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Neurotoxicity of heroin-cocaine combinations in rat cortical neurons
Abstract
Cocaine and heroin are frequently co-abused by humans, in a combination known as speedball. Recently, chemical interactions between heroin (Her) or its metabolite morphine (Mor) and cocaine (Coc) were described, resulting in the formation of strong adducts. In this work, we evaluated whether combinations of Coc and Her affect the neurotoxicity of these drugs, using rat cortical neurons incubated with Coc, Her, Her followed by Coc (Her+Coc) and Her plus Coc (Her:Coc, 1:1). Neurons exposed to Her, Her+Coc and Her:Coc exhibited a decrease in cell viability, which was more pronounced in neurons exposed to Her and Her+Coc, in comparison with neurons exposed to the mixture (Her:Coc). Cells exposed to the mixture showed increased intracellular calcium and mitochondrial dysfunction, as determined by a decrease in intracellular ATP levels and in mitochondrial membrane potential, displaying both apoptotic and necrotic characteristics. Conversely, a major increase in cytochrome c release, caspase 3-dependent apoptosis, and decreased metabolic neuronal viability were observed upon sequential exposure to Her and Coc. The data show that drug combinations potentiate cortical neurotoxicity and that the mode of co-exposure changes cellular death pathways activated by the drugs, strongly suggesting that chemical interactions occurring in Her:Coc, such as adduct formation, shift cell death mechanisms towards necrosis. Since impairment of the prefrontal cortex is involved in the loss of impulse control observed in drug addicts, the data presented here may contribute to explain the increase in treatment failure observed in speedball abusers.
... An increase in extracellular glutamate has been associated with excitotoxic processes, due to increased activation of N-methyld-aspartate (NMDA) receptors and subsequent increase in intracellular Ca 2+ concentration (Ca 2+ i ) (Rego & Oliveira, 2003, for review), which could contribute to cocaine neurotoxicity. Indeed, an increase in Ca 2+ i was observed in rat cortical neurons, after cocaine exposure (Cunha- Oliveira et al., 2010). ...
... Thus, besides pharmacodynamic interactions, chemical interactions between drugs could also play a role in speedball neurotoxicity. Primary cultures of rat cortical neurons were either sequentially or simultaneously exposed to heroin and/or cocaine (Cunha- Oliveira et al., 2010), to investigate this possibility. The effects of cocaine seemed to predominate over heroin's effects when the cells were exposed to a mixture of the two drugs (where the probability of chemical interactions between the drugs is enhanced), but not upon sequential exposure (Cunha- Oliveira et al., 2010). ...
... Primary cultures of rat cortical neurons were either sequentially or simultaneously exposed to heroin and/or cocaine (Cunha- Oliveira et al., 2010), to investigate this possibility. The effects of cocaine seemed to predominate over heroin's effects when the cells were exposed to a mixture of the two drugs (where the probability of chemical interactions between the drugs is enhanced), but not upon sequential exposure (Cunha- Oliveira et al., 2010). Since both drugs were present at the same amounts in both situations, this result suggested that the interaction of the mixture of drugs with opioid receptors may be lower, as compared to a sequential administration of the two drugs, probably due to the presence of cocaine-morphine adducts. ...
... Since cocaine massively increases dopamine levels in the brain, culminating in cell death, we studied the LINS effects on a cocaine model of dopamine-induced neurotoxicity (Garcia et al. 2012;Garcia et al. 2019;Cunha-Oliveira et al. 2006;Garcia et al. 2017;Kuhar et al. 1991;Kovacic 2005;Cunha-Oliveira et al. 2010). Metoclopramide, a selective D 2 R antagonist, and haloperidol, a D 2 R/ D 3 R antagonist, were used to verify the possible preventive actions at dopamine receptors (Sanger and Andrews A C B ...
... MTT assay showed that 10 µM LINS01003, LINS01004, and LINS01011, as well as 10 µM metoclopramide and 10 µM haloperidol, showed a partially preventive effect when incubated in the presence of cocaine LC50 using SH-SY5Y cell line for 48 h. Although studies approaching the biological effects of cocaine require micromolar concentrations of the drug, several in vitro studies use millimolar concentrations (up to 2.5 mM) to induce a rapid neuronal death, mimicking chronic cocaine exposure pattern on cells (Garcia et al. 2012;Garcia et al. 2019;Imam et al. 2005;Lepsch et al. 2009;Cunha-Oliveira et al. 2010;Numa et al. 2011). It is important to highlight that cocaine concentration used in this study was somewhat comparable to cocaine plasma concentration in human drug abusers reported in the literature, ranging from 0.0003 to 1 mM (Nakamura and Noguchi 1981;Mittleman and Wetli 1984;Peretti et al. 1990;Albuquerque and Kurth 1993;Yuan and Acosta 2000). ...
... As previously demonstrated in metamphetamine, MDMA, and MPTP exposure, dopamine receptors blockade may be protective against drug-induced increase of dopamine (Beauvais et al. 2011;Granado et al. 2011;Chen et al. 2013). However, cocaine also induces other effects such as oxidative stress, mitochondrial dysfunction, and caspase cascade activation (Cunha-Oliveira et al. 2006;Kovacic 2005;Cunha-Oliveira et al. 2010). ...
Excessive levels of dopamine in the synaptic cleft, induced by cocaine for example, activates dopaminergic receptors, mainly D1R, D2R, and D3R subtypes, contributing to neurotoxic effects. New synthetic 1-[(2,3-dihydro-1-benzofuran-2-yl)methyl]piperazine derivatives (the LINS01 compounds), designed as histaminergic receptor (H3R) ligands, are also dopaminergic receptor ligands, mainly D2R and D3R. This study aims to evaluate the neurotoxicity of these new synthetic LINS01 compounds (LINS01003, LINS01004, LINS01011, and LINS01018), as well as to investigate their protective potential on a cocaine model of dopamine-induced neurotoxicity using SH-SY5Y cell line culture. Neurotoxicity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and automated cell counting with fluorescent dyes (acridyl orange and propidium iodide) assays. Concentration-response curves (CRCs) were performed for all LINS compounds and cocaine using MTT assay. The results show that LINS series did not decrease cell viability after 48h of exposure—except for 100 µM LINS01018, which was discontinued from the study. Likewise, MTT, LDH, and fluorescent dyes staining showed no difference is cell viability for LINS compounds at 10 µM. When incubated with 2.5 mM cocaine (lethal concentration 50) for 48h, 10 µM of each LINS compound, metoclopramide (D2R antagonist) and haloperidol (D2R/D3R antagonist), ameliorated cocaine-induced neurotoxicity. However, only metoclopramide, haloperidol, and LINS01011 compound significantly decreased LDH released in the culture medium, suggesting that this new synthetic compound presents a more robust effect. This preliminary in vitro neurotoxicity study suggests that LINS01 compounds are not neurotoxic, and that they play a promising role in preventing cocaine-induced neurotoxicity.
... 1. In rat primary cortical neurons acute exposure to cocaine (1 mM, 24 h) resulted in disruption of mitochondrial membrane potential [27,28] as well as accumulation of intracellular Ca 2+ and decreased cellular ATP levels [28]. Human primary neurons also demonstrated ATP depletion after cocaine exposure (1 mM, 48 h; [29]). ...
... 1. In rat primary cortical neurons acute exposure to cocaine (1 mM, 24 h) resulted in disruption of mitochondrial membrane potential [27,28] as well as accumulation of intracellular Ca 2+ and decreased cellular ATP levels [28]. Human primary neurons also demonstrated ATP depletion after cocaine exposure (1 mM, 48 h; [29]). ...
... Interestingly, Neuro 2a neuronal-like cells exposed to high concentrations of cocaine (4 mM) showed no change in viability [59]. Cell death markers have also been observed in response to cocaine exposure in primary cortical neurons [27,28] striatal neurons [60,61] and microglia [58] with a cocaine concentration between 1 mM and 1 mM. Cell viability decreased in line with mitochondrial function (measured by MTT) in rat primary hippocampal neurons (1-2 mM, 48 h; [29]). ...
The incidence of cocaine abuse is increasing especially in the U.K. where the rates are among the highest in Europe. In addition to its role as a psychostimulant, cocaine has profound effect on brain metabolism, impacting glycolysis and impairing oxidative phosphorylation. Cocaine exposure alters metabolic gene expression and protein networks in brain regions including the prefrontal cortex, the ventral tegmental area and the nucleus accumbens, the principal nuclei of the brain reward system. Here, we focus on how cocaine impacts mitochondrial function, in particular through alterations in electron transport chain function, reactive oxygen species (ROS) production and oxidative stress (OS), mitochondrial dynamics and mitophagy. Finally, we describe the impact of cocaine on brain energy metabolism in the developing brain following prenatal exposure. The plethora of mitochondrial functions altered following cocaine exposure suggest that therapies maintaining mitochondrial functional integrity may hold promise in mitigating cocaine pathology and addiction.
... In vitro studies showed that cocaine activates apoptotic signaling pathways. Cocaine exposure was shown to dissipate ΔΨ m in rat cortical neurons (Cunha- Oliveira et al., 2006aOliveira et al., , 2010, in isolated brain mitochondria (Cunha- Oliveira et al., 2013d), and in C6 astroglioma cells (Badisa, Darling-Reed, & Goodman, 2010). Further evidence for the activation of the intrinsic apoptotic signaling by cocaine includes alterations in Bcl-2 and Bax protein levels (Dey, Mactutus, Booze, & Snow, 2007;Lepsch et al., 2009;Xiao & Zhang, 2008), cytochrome c (Cunha- Oliveira et al., 2006aOliveira et al., , 2010, and AIF (Alvaro-Bartolome et al., 2011) release from mitochondria, and caspase-9 activation (Cunha- Oliveira et al., 2006a). ...
... Cocaine exposure was shown to dissipate ΔΨ m in rat cortical neurons (Cunha- Oliveira et al., 2006aOliveira et al., , 2010, in isolated brain mitochondria (Cunha- Oliveira et al., 2013d), and in C6 astroglioma cells (Badisa, Darling-Reed, & Goodman, 2010). Further evidence for the activation of the intrinsic apoptotic signaling by cocaine includes alterations in Bcl-2 and Bax protein levels (Dey, Mactutus, Booze, & Snow, 2007;Lepsch et al., 2009;Xiao & Zhang, 2008), cytochrome c (Cunha- Oliveira et al., 2006aOliveira et al., , 2010, and AIF (Alvaro-Bartolome et al., 2011) release from mitochondria, and caspase-9 activation (Cunha- Oliveira et al., 2006a). This apoptotic signaling is associated with mitochondrial dysfunction in rat cortical neurons, occurring simultaneously with decreased ATP levels and increased intracellular calcium concentration (Cunha- Oliveira et al., 2010), which may be partially explained by the loss of ΔΨ m that drives mitochondrial calcium uptake. ...
... Further evidence for the activation of the intrinsic apoptotic signaling by cocaine includes alterations in Bcl-2 and Bax protein levels (Dey, Mactutus, Booze, & Snow, 2007;Lepsch et al., 2009;Xiao & Zhang, 2008), cytochrome c (Cunha- Oliveira et al., 2006aOliveira et al., , 2010, and AIF (Alvaro-Bartolome et al., 2011) release from mitochondria, and caspase-9 activation (Cunha- Oliveira et al., 2006a). This apoptotic signaling is associated with mitochondrial dysfunction in rat cortical neurons, occurring simultaneously with decreased ATP levels and increased intracellular calcium concentration (Cunha- Oliveira et al., 2010), which may be partially explained by the loss of ΔΨ m that drives mitochondrial calcium uptake. However, the induction of structural apoptotic hallmarks by cocaine is not consensual in the literature. ...
Cocaine is a lipophilic weak base with a positive charge at physiological pH, which may accumulate in mitochondria and dissipate the mitochondrial transmembrane potential. Cocaine impairs mitochondrial respiration through a direct effect on complex I. Acute cocaine exposure activates mitochondrial apoptotic signaling and induces oxidative stress in the brain, which may be a cause or a consequence of mitochondrial dysfunction. In contrast, long-term cocaine exposure induces adaptation to oxidative stress. Cocaine-induced mitochondrial dysfunction may be a cause, or effect, of altered epigenetic mechanisms that may account for some of the long-term effects of cocaine on the users or in their progeny.
... In a study involving only male subjects, cocaine use reduced glucose brain metabolism in 26 out of 29 brain regions (London et al., 1990), an effect that persisted at least 4 months after cocaine detoxification (Volkow et al., 1992). In vitro, primary cortical neurones exposed to cocaine show reduced ATP production and decreased mitochondrial potential (Cunha-Oliveira et al., 2006;Cunha-Oliveira et al., 2010;De Simone et al., 2016). Other studies confirmed that the reduction in ATP, at least in part, is a direct effect of the drug on mitochondria rather than a consequence of perturbed cellular dynamics (Cunha-Oliveira et al., 2013a, 2013bYuan & Acosta, 2000;Lehrmann et al., 2003;Zhou et al., 2011;Bhattacherjee et al., 2019;Dietrich et al., 2004). ...
... Neuro-2a cells at approximatively 80% confluency in 150-mm tissue culture plates (Corning Inc.) were treated for 24 h either with 1 mM cocaine dissolved in saline or with an equivalent volume of saline (control) in Opti-MEM (Thermo Fisher Scientific), an EV-and serum-free optimised cell medium. This dose of cocaine is known to stimulate mitochondrial dysfunction in the absence of cell death (Cunha-Oliveira et al., 2010), as also confirmed by our data ( Figure 5). Furthermore, Neuro-2a cells are known to grow well in Opti-MEM without addition of serum (Li et al., 2015). ...
Cocaine, an addictive psychostimulant, has a broad mechanism of action, including the induction of a wide range of alterations in brain metabolism and mitochondrial homeostasis. Our group recently identified a subpopulation of non‐microvesicular, non‐exosomal extracellular vesicles of mitochondrial origin (mitovesicles) and developed a method to isolate mitovesicles from brain parenchyma. We hypothesised that the generation and secretion of mitovesicles is affected by mitochondrial abnormalities induced by chronic cocaine exposure. Mitovesicles from the brain extracellular space of cocaine‐administered mice were enlarged and more numerous when compared to controls, supporting a model in which mitovesicle biogenesis is enhanced in the presence of mitochondrial alterations. This interrelationship was confirmed in vitro. Moreover, cocaine affected mitovesicle protein composition, causing a functional alteration in mitovesicle ATP production capacity. These data suggest that mitovesicles are previously unidentified players in the biology of cocaine addiction and that target therapies to fine‐tune brain mitovesicle functionality may be beneficial to mitigate the effects of chronic cocaine exposure.
... Cocaine could bind to dopamine transport proteins and thus directly prevent the reuptake of dopamine. 72,73,75,76 Overdosage of Cocaine could trigger toxic effects such as rhabdomyolysis and acute liver injury. 68,69,71,77 Structurally, the drug is a benzoic acid ester with an ionizable tertiary amino group. ...
... For deprotonated G5, only one stable interaction pattern/orientation for the inter-molecular -N-H···O=C-hydrogen bond is observed. 76 Fig. S7. Comparison between the AM1 and B3LYP/6-31G* optimized structures in the new round of charge fitting for the deprotonated and protonated forms of Ketamine (G5) and Cocaine (G7). ...
Describing, understanding, and designing complex interaction networks within macromolecular systems remain challenging in modern chemical research. Host-guest systems, despite their relative simplicity in both the structural feature and interaction patterns, still pose problems in theoretical modelling. The barrel-shaped supra-molecular container Cucurbit[8]uril (CB8) shows promising functionalities in various areas, e.g., catalysis and molecular recognition. It can stably coordinate a series of structurally diverse guests with high affinities. In this work, we examine the binding of 7 commonly abused drugs to the CB8 host, aiming at providing a general picture of CB8-guest binding. A thorough comparison of widely used fixed-charge models for drug-like molecules is presented. Extensive sampling of the configurational space of these host-guest systems is performed, and the binding pathway and interaction patterns of CB8-guest complexes are investigated in detail. Iterative refitting of the atomic charges suggests significant conformation-dependence of charge generation. The initial model generated at the original conformation could be inaccurate for new conformations explored during conformational search. Our investigations of the configurational space of CB8-drug complexes suggest that the host-guest interactions are more complex than expected. Despite the structural simplicities of these molecules, the conformational fluctuations of the host and the guest molecules and orientations of functional groups lead to the existence of an ensemble of binding modes (e.g., bracelet-like guest conformations and crescent free energy landscapes). Thus, understandings obtained from static calculations based on a single or several structures are limited for these host-guest interactions. The investigation protocol provides useful guidelines for studying host-guest binding, and the insights of the binding thermodynamics, performance of fixed-charge models, and binding patterns of the CB8-guest systems are useful for elucidating the binding mechanism of other host-guest complexes.
... Cocaine could bind to dopamine transport proteins and thus directly prevent the reuptake of dopamine. 72,73,75,76 Overdosage of Cocaine could trigger toxic effects such as rhabdomyolysis and acute liver injury. 68,69,71,77 Structurally, the drug is a benzoic acid ester with an ionizable tertiary amino group. ...
... For deprotonated G5, only one stable interaction pattern/orientation for the inter-molecular -N-H···O=C-hydrogen bond is observed. 76 Fig. S7. Comparison between the AM1 and B3LYP/6-31G* optimized structures in the new round of charge fitting for the deprotonated and protonated forms of Ketamine (G5) and Cocaine (G7). ...
Describing, understanding, and designing complex interaction networks within macromolecular systems remain challenging in modern chemical research. Host-guest systems, despite their relative simplicity in both the structural feature and interaction patterns, still pose problems in theoretical modelling. The barrel-shaped supra-molecular container Cucurbit[8]uril (CB8) shows promising functionalities in various areas, e.g., catalysis and molecular recognition. It can stably coordinate a series of structurally diverse guests with high affinities. In this work, we examine the binding of 7 commonly abused drugs to the CB8 host, aiming at providing a general picture of CB8-guest binding. A thorough comparison of widely used fixed-charge models for drug-like molecules is presented. Extensive sampling of the configurational space of these host-guest systems is performed, and the binding pathway and interaction patterns of CB8-guest complexes are investigated in detail. Iterative refitting of the atomic charges suggests significant conformation-dependence of charge generation. The initial model generated at the original conformation could be inaccurate for new conformations explored during conformational search. Our investigations of the configurational space of CB8-drug complexes suggest that the host-guest interactions are more complex than expected. Despite the structural simplicities of these molecules, the conformational fluctuations of the host and the guest molecules and orientations of functional groups lead to the existence of an ensemble of binding modes (e.g., bracelet-like guest conformations and crescent free energy landscapes). Thus, understandings obtained from static calculations based on a single or several structures are limited for these host-guest interactions. The investigation protocol provides useful guidelines for studying host-guest binding, and the insights of the binding thermodynamics, performance of fixed-charge models, and binding patterns of the CB8-guest systems are useful for elucidating the binding mechanism of other host-guest complexes.
... The combination of psychostimulants and opioids, generally cocaine and heroin, is popularly known as 'speedball' (Cunha-Oliveira et al., 2010;Leri et al., 2003;Park et al., 2018;Trujillo et al., 2011). Such couse of cocaine with heroin or synthetic opioids has been linked with an increase in cocaine-related fatal overdose in the US (Jones et al., 2017;Pichini et al., 2018) and with an increased risk of neurotoxicity and behavioral change in some animal studies (Cunha-Oliveira et al., 2010;Trujillo et al., 2011). ...
... The combination of psychostimulants and opioids, generally cocaine and heroin, is popularly known as 'speedball' (Cunha-Oliveira et al., 2010;Leri et al., 2003;Park et al., 2018;Trujillo et al., 2011). Such couse of cocaine with heroin or synthetic opioids has been linked with an increase in cocaine-related fatal overdose in the US (Jones et al., 2017;Pichini et al., 2018) and with an increased risk of neurotoxicity and behavioral change in some animal studies (Cunha-Oliveira et al., 2010;Trujillo et al., 2011). Furthermore, the symptoms of cocaine-induced myocardial infarction (e.g., chest pain) may be masked by co-administration of heroin. ...
Background:
Impurities in commonly used illicit drugs raise concerns for unwitting consumers when pharmacologically active adulterants, especially new psychoactive substances (NPS), are used. This study examines impurities detected in illicit drugs seized in one Australian jurisdiction.
Methods:
Queensland Health Forensic and Scientific Services provided analytical data. Data described the chemical composition of 9346 samples of 11 illicit drugs seized by police during 2015-2016. Impurities present in primary drugs were summarized and tabulated. A systematic search for published evidence reporting similar analyses was conducted.
Results:
Methamphetamine was the primary drug in 6608 samples, followed by MDMA (1232 samples) and cocaine (516 samples). Purity of primary drugs ranged from ∼30% for cocaine, 2-CB and GHB to >90% for THC, methamphetamine, heroin and MDMA. Methamphetamine and MDMA contained the largest variety of impurities: 22 and 18 variants, respectively. Drug adulteration patterns were broadly similar to those found elsewhere, including NPS, but in some primary drugs impurities were found which had not been reported elsewhere. Psychostimulants were adulterated with each other. Levamisole was a common impurity in cocaine. Psychedelics were adulterated with methamphetamine and NPS. Opioids were quite pure, but some samples contained methamphetamine and synthetic opioids.
Conclusions:
Impurities detected were mostly pharmacologically active adulterants probably added to enhance desired effects or for active bulking. Given the designer nature of these drug cocktails, the effects of the adulterated drugs on users from possible complex multi-drug interactions is unpredictable. Awareness-raising among users, research into complex multi-drug effects and ongoing monitoring is required.
... Additionally, individuals may experience depression, a sense of detachment from reality, emotional volatility, and, in more severe instances, nightmares, hallucinations, substance dependency, withdrawal symptoms, and an increased risk of suicidal ideation [44,45]. CNS is particularly susceptible to the effects of tramadol and often exhibits heightened sensitivity to various neurotoxic drugs, which can induce oxidative stress, promote apoptosis, and inhibit neurogenesis [46,47]. The current literature review examined the effect of prolonged tramadol use on various brain regions in animals, with particular emphasis on oxidative stress, autophagy, and apoptosis, all of which contribute to neurodegenerative processes. ...
Tramadol is often recommended by healthcare professionals to help manage pain levels in patients suffering from various illnesses. Several studies have confirmed a connection between tramadol use and increased oxygen-free radicals, as well as activation of apoptosis and autophagy signaling pathways. These factors could damage the neuronal activities and ultimately cause brain damage. The abuse of tramadol is becoming more prevalent, with a noticeable rise in incidents involving poisoning and even fatalities associated with this particular drug. There has been a lack of review articles specifically examining the impacts of tramadol on neurodegeneration by focusing the oxidative stress, autophagy, and apoptosis sig-naling pathways. The objective of this current research was to examine the most recent animal experiments regarding the impact of prolonged tramadol exposure on causing neurotoxicity via oxidative stress, autophagy, and apoptosis pathways. Specially, provides insights into molecular and cellular mechanisms. This review indicates the increase of oxidative stress activity, apopto-sis, and neuroinflammation and the decrease of antioxidant enzymes and neurotrophic factors following the chronic use of tramadol in different brain regions in animals. This implies that the damage caused to the nerve cells can be regarded as the primary concern when considering the chronic administration of this medication. Future research should prioritize well-designed clinical trials to assess the safety and effectiveness of tramadol in humans.
... As a psychostimulant, it exerts its effects primarily by influencing monoamine neurotransmitters (Xu et al., 2013). Cocaine neurotoxicity and neurological damage stem from several mechanisms, including mitochondrial dysfunction (Cunha-Oliveira et al., 2010), oxidative stress (Poon et al., 2007), neuroinflammation (Correia et al., 2020), excitotoxicity (Moran et al., 2005), and autophagy (Cao et al., 2017). ...
The recreational abuse of addictive drugs poses considerable challenges to public health, leading to widespread neurotoxicity and neurological dysfunction. This review comprehensively examines the neurotoxic mechanisms, clinical manifestations, and treatment strategies associated with six commonly abused substances: methamphetamine, cocaine, synthetic cathinones, ketamine, nitrous oxide and heroin. Despite their diverse pharmacological properties, these drugs converge on shared neurotoxic pathways, including oxidative stress, mitochondrial dysfunction, excitotoxicity, and neuroinflammation. Psychostimulants, such as methamphetamine, cocaine and synthetic cathinones, disrupt monoaminergic neurotransmission, causing cognitive impairment, psychiatric disturbances, and neurovascular damage. Dissociative anesthetics, including ketamine and nitrous oxide, impair glutamatergic transmission and mitochondrial function, thereby exacerbating excitotoxicity and neuronal apoptosis. Opioids, such as heroin, primarily target the brain’s reward system and induce oxidative stress, neuroinflammation, and cerebrovascular complications. Treatment strategies remain limited, focusing on symptomatic management, neuroprotective interventions, and behavioral therapies. Emerging approaches, such as antioxidants, NMDA receptor modulators, and cognitive rehabilitation, show promise but require further validation. By highlighting the underlying mechanisms and therapeutic challenges, this review provides a foundation for developing targeted interventions and advancing research on drug-induced neurotoxicity.
... The chemical composition of nyaope suggests that the cell toxicity induced by nyaope is likely mediated by heroin and its related compounds, or to other drugs present in the nyaope cocktail (caffeine) or a combination thereof. Insights into the toxic mechanisms of heroin (Cunha-Oliveira et al., 2010) and caffeine (Herz, 1999) may subsequently offer a possible explanation for the observed nyaope-induced toxic effects. ...
Nyaope is a local adulterated drug that contributes significantly to the psychosocial challenge of substance use in South Africa. Despite being a huge burden on society and the health care system, research into the deleterious effects of nyaope is limited. The aim of the present study was therefore to perform a chemical analysis of the drug and to assess its toxic effects on neuroblastoma cells. Gas chromatography-mass spectrometry (GC/MS) analysis showed that nyaope mainly consists of heroin and heroin-related products. SH-SY5Y cells were subsequently exposed to increasing concentrations of nyaope (0.625, 1.25, 2.5, 5 and 10 µg/µL) for 1, 6 or 24 h. The toxic effects of nyaope were determined by measuring lactate dehydrogenase (LDH) released into the cell culture medium as an indicator of necrosis, the mRNA expression levels of Bax and Bcl-2 as markers of apoptosis, and the mRNA expression levels of p62 and microtubule-associated protein 1 A/1B light-chain 3 (LC3) as indicators of autophagy. Exposing SH-SY5Y cells to concentrations of nyaope 5 µg/µL and greater for 24 h, resulted in a significant increase in LDH levels in the cell culture medium, unchanged mRNA expression of Bax and Bcl-2 mRNA, and significantly reduced p62 and elevated LC3 mRNA expression levels. The chemical analysis suggests that nyaope should be considered synonymous with heroin and the toxic effects of the drug may recruit pathways involved in necrosis and autophagy.
... Persons with OUD often have a history of using other substances (e.g., psychostimulants), alcohol and nicotine, each with its own potential effects on immune function (Redwine et al., 2003;Alfonso-Loeches et al., 2010;Fox et al., 2012;Ahearn et al., 2021;Rodas et al., 2021). Common patterns of poly-drug use (e.g., opioids and cocaine) may also cause more severe neurotoxicity than opioid use alone (Cunha-Oliveira et al., 2010). ...
Opioid use disorder (OUD) is a major current cause of morbidity and mortality. Long-term exposure to short-acting opioids (MOP-r agonists such as heroin or fentanyl) results in complex pathophysiological changes to neuroimmune and neuroinflammatory functions, affected in part by peripheral mechanisms (e.g., cytokines in blood), and by neuroendocrine systems such as the hypothalamic-pituitary-adrenal (HPA) stress axis. There are important findings from preclinical models, but their role in the trajectory and outcomes of OUD in humans is not well understood. The goal of this narrative review is to examine available data on immune and inflammatory functions in persons with OUD, and to identify major areas for future research. Peripheral blood biomarker studies revealed a pro-inflammatory state in persons with OUD in withdrawal or early abstinence, consistent with available postmortem brain studies (which show glial activation) and diffusion tensor imaging studies (indicating white matter disruptions), with gradual abstinence-associated recovery. The mechanistic roles of these neuroimmune and neuroinflammatory changes in the trajectory of OUD (including recovery and medication management) cannot be examined practically with postmortem data. Collection of longitudinal data in larger-scale human cohorts would allow examination of these mechanisms associated with OUD stage and progression. Given the heterogeneity in presentation of OUD, a precision medicine approach integrating multi-omic peripheral biomarkers and comprehensive phenotyping, including neuroimaging, can be beneficial in risk stratification, and individually optimized selection of interventions for individuals who will benefit, and assessments under refractory therapy.
... For example, repeated morphine administration in mice downregulates TSP expression in the cortex 24 h after the final injection, as well as in cultured astrocytes following repeated morphine treatment [79]. One mechanism by which heroin may impact TSP expression is through increased oxidative stress, as evidenced by the induction of oxidative stress in humans following chronic heroin exposure [80] and also in cultured cortical neurons [81,82]. Moreover, cultured primary astrocytes reduce TSP-1 gene expression under increased oxidative stress conditions, which is prevented by NAC [83]. ...
Clinical and preclinical studies indicate that adaptations in corticostriatal neurotransmission significantly contribute to heroin relapse vulnerability. In animal models, heroin self-administration and extinction produce cellular adaptations in both neurons and astrocytes within the nucleus accumbens (NA) core that are required for cue-induced heroin seeking. Specifically, decreased glutamate clearance and reduced association of perisynaptic astrocytic processes with NAcore synapses allow glutamate release from prelimbic (PrL) cortical terminals to engage synaptic and structural plasticity in NAcore medium spiny neurons. Normalizing astrocyte glutamate homeostasis with drugs like the antioxidant N-acetylcysteine (NAC) prevents cue-induced heroin seeking. Surprisingly, little is known about heroin-induced alterations in astrocytes or pyramidal neurons projecting to the NAcore in the PrL cortex (PrL-NAcore). Here, we observe functional adaptations in the PrL cortical astrocyte following heroin self-administration (SA) and extinction as measured by the electrophysiologically evoked plasmalemmal glutamate transporter 1 (GLT-1)-dependent current. We likewise observed the increased complexity of the glial fibrillary acidic protein (GFAP) cytoskeletal arbor and increased association of the astrocytic plasma membrane with synaptic markers following heroin SA and extinction training in the PrL cortex. Repeated treatment with NAC during extinction reversed both the enhanced astrocytic complexity and synaptic association. In PrL-NAcore neurons, heroin SA and extinction decreased the apical tuft dendritic spine density and enlarged dendritic spine head diameter in male Sprague–Dawley rats. Repeated NAC treatment during extinction prevented decreases in spine density but not dendritic spine head expansion. Moreover, heroin SA and extinction increased the co-registry of the GluA1 subunit of AMPA receptors in both the dendrite shaft and spine heads of PrL-NAcore neurons. Interestingly, the accumulation of GluA1 immunoreactivity in spine heads was further potentiated by NAC treatment during extinction. Finally, we show that the NAC treatment and elimination of thrombospondin 2 (TSP-2) block cue-induced heroin relapse. Taken together, our data reveal circuit-level adaptations in cortical dendritic spine morphology potentially linked to heroin-induced alterations in astrocyte complexity and association at the synapses. Additionally, these data demonstrate that NAC reverses PrL cortical heroin SA-and-extinction-induced adaptations in both astrocytes and corticostriatal neurons.
... Synaptic loss is considered an indicator for axonal damage or axonal transport disturbances in various neurological pathologies of the brain [49] . Mitochondrial dysfunction, oxidative stress, hindrance of synaptogenesis and enhanced apoptosis were described as the causes of opioids neurotoxicity [50,51] . ...
... Moreover, chronic opioid administration causes neurotoxicity in the brain (Mao et al., 2002). Neurotoxicity induced by opioids is commonly caused by mitochondrial dysfunction, oxidative stress, apoptosis, and inhibition of synaptogenesis and neurogenesis (Awadalla & Salah-Eldin, 2016;Cunha-Oliveira et al., 2010). It has been shown that chronic tramadol administration enhanced the apoptosis process in the cerebral cortex of the experimental model (Ghoneim et al., 2014). ...
Tramadol is a synthetic opioid with centrally acting analgesic activity that alleviates moderate to severe pain and treats withdrawal symptoms of the other opioids. Like other opioid drugs, tramadol abuse has adverse effects on central nervous system components. Chronic administration of tramadol induces maladaptive plasticity in brain structures responsible for cognitive function, such as the hippocampus. However, the mechanisms by which tramadol induces these alternations are not entirely understood. Here, we examine the effect of tramadol on apoptosis and synaptogenesis of hippocampal neuronal in vitro. First, the primary culture of hippocampal neurons from neonatal rats was established, and the purity of the neuronal cells was verified by immunofluorescent staining. To evaluate the effect of tramadol on neuronal cell viability MTT assay was carried out. The western blot analysis technique was performed for the assessment of apoptosis and synaptogenesis markers. Results show that chronic exposure to tramadol reduces cell viability of neuronal cells and naloxone reverses this effect. Also, the level of caspase‐3 significantly increased in tramadol‐exposed hippocampal neurons. Moreover, tramadol downregulates protein levels of synaptophysin and stathmin as synaptogenesis markers. Interestingly, the effects of tramadol were abrogated by naloxone treatment. These findings suggest that tramadol can induce neurotoxicity in hippocampal neuronal cells, and this effect was partly mediated through opioid receptors.
... In vivo and in vitro studies have also shown that cocaine has a neurotoxic potential. Cunha-Oliveira et al. saw that 1 mM of cocaine led to an increase in calcium concentrations and caspase-3 activity, as well as a decrease in mitochondrial membrane potential and ATP in rat cortical neurons exposed for 24 h [112]. Furthermore, cocaine exposure in models of rat primary hippocampal neurons (1 mM) and mouse primary cortical neurons (1, 10, 100 and 200 µM) increased the expression of autophagy markers LC-3 I and II [113,114]. ...
Cocaine is one of the most consumed stimulants throughout the world, as official sources report. It is a naturally occurring sympathomimetic tropane alkaloid derived from the leaves of Erythroxylon coca, which has been used by South American locals for millennia. Cocaine can usually be found in two forms, cocaine hydrochloride, a white powder, or ‘crack’ cocaine, the free base. While the first is commonly administered by insufflation (‘snorting’) or intravenously, the second is adapted for inhalation (smoking). Cocaine can exert local anaesthetic action by inhibiting voltage-gated sodium channels, thus halting electrical impulse propagation; cocaine also impacts neurotransmission by hindering monoamine reuptake, particularly dopamine, from the synaptic cleft. The excess of available dopamine for postsynaptic activation mediates the pleasurable effects reported by users and contributes to the addictive potential and toxic effects of the drug. Cocaine is metabolised (mostly hepatically) into two main metabolites, ecgonine methyl ester and benzoylecgonine. Other metabolites include, for example, norcocaine and cocaethylene, both displaying pharmacological action, and the last one constituting a biomarker for co-consumption of cocaine with alcohol. This review provides a brief overview of cocaine’s prevalence and patterns of use, its physical-chemical properties and methods for analysis, pharmacokinetics, pharmacodynamics, and multi-level toxicity.
... However, similar research on the predictor markers of future health of offspring are warranted. Opioid use stimulates telomere shortening and age-related disease in adults [36][37][38][39], which raises a question how it may affect aging and aging biomarkers trans-generationally in the offspring of users? In the current research, we aimed to study telomere length in umbilical cord blood of newborns born to opioid consuming mothers compared to normal controls. ...
Opioid use accelerates normal aging in adults that raises a question on whether it may trans-generationally affect aging and aging biomarkers in the offspring of users as well? In the present research, we investigated the relative telomere length in umbilical cord blood of newborns born to opioid consuming mothers compared to normal controls. Telomere length shortening is a known biomarker of aging and aging related diseases. Its measure at birth or early in life is considered as a predictor of individual health in adulthood. Here, we performed a case-control study to investigate whether maternal opioid use affects newborns relative telomere length (RTL). 57 mother-newborn dyads were included in this study, 30 neonates with opioid using mothers (OM), and 27 with not-opioid using mothers (NOM)). RTL was measured in leukocyte cells genomic DNA using real-time PCR. The correlation of maternal opioid use with neonates telomer length was assessed using logistic regression analysis. The results displayed a significant association between odds ratio of long RTL and maternal opioid use when sensitivity analysis was performed by neonate sex; where the data indicates significantly increased odds ratio of long leukocyte RTL in association with maternal opioid use in male neonates only. Further work is necessary to assess this association in larger samples and test the potential underlying mechanisms for this observation.
... More studies have analyzed the effects of the cocaine and heroin co-use [6]. The combination of cocaine and heroin is more neurotoxic than each drug alone [28], with super-addictive or addictive effects [29]. Logistic regression analysis applied to our data confirmed that polydrug use represents a risk factor with respect to monodrug use. ...
Polydrug use is a frequent pattern of consumption in Europe. This behavior has mainly been analyzed within restricted groups; more rarely in large populations. Current polydrug use is less studied than simultaneous use. This study focused on the concurrent assumption of polydrug among drivers using hair matrix. Hair matrix, for its biological characteristics, allows to identify illicit drug use more often than other matrices, i.e., urine, and it provides information on the long-term use of them. Hair samples of subjects positive for opiates, cocaine and delta-9-tetrahydrocannabinol (Δ9-THC) collected by the forensic toxicology laboratory of the University of Macerata in the period 2010–2020, were analyzed using a gas chromatography-mass spectrometry method. Our results evidenced that a significant part of the examined population (12.15%) used polydrug. A strong predominance of males over females was evident. Polydrug users were more frequently young people. The abuse of two substances was predominant. Cocaine and Δ9-THC was the most common combination, followed by cocaine and morphine, and morphine and Δ9-THC. The timeframe of polydrug use was also analyzed. Our study shows that polydrug use is a very frequent behavior, and that hair analysis may be a powerful tool to obtain objective biological information of this complex phenomenon.
... Even though further study is needed to determine whether ERBB3 also negatively affects neurons in the brain, we can estimate that an increase of ERBB3 in the striatum in response to cocaine and, especially, heroin may exert a negative effect on cell survival based on previous reports. 64,65 The PTK2B gene encodes a non-receptor tyrosine kinase, Pyk2 that is activated by intracellular calcium and highly expressed in the CNS. 66 In this research, we found that PTK2B mRNA expression was reduced in the striatum by cocaine and, especially, heroin. ...
Cocaine and heroin cause impairment of neural plasticity in the brain including striatum. This study aimed to identify genes differentially expressed in the striatum of cynomolgus monkeys in response to cocaine and heroin. After chronic administration of cocaine and heroin in the monkeys, we performed large‐scale transcriptome profiling in the striatum using RNA‐Seq technology and analysed functional annotation. We found that 547 and 1238 transcripts were more than 1.5‐fold up‐ or down‐regulated in cocaine‐ and heroin‐treated groups, respectively, compared to the control group, and 3432 transcripts exhibited differential expression between cocaine‐ and heroin‐treated groups. Functional annotation analysis indicated that genes associated with nervous system development (NAGLU, MOBP and TTL7) and stress granule disassembly (KIF5B and KLC1) were differentially expressed in the cocaine‐treated group compared to the control group, whereas gene associated with neuron apoptotic process (ERBB3) was differentially expressed in the heroin‐treated group. In addition, IPA network analysis indicated that genes (TRAF6 and TRAF3IP2) associated with inflammation were increased by the chronic administration of cocaine and heroin. These results provide insight into the correlated molecular mechanisms as well as the upregulation and down‐regulation of genes in the striatum after chronic exposure to cocaine and heroin.
... For example, repeated morphine administration in mice downregulates TSP-1 gene expression in the cortex 24 hours after the final injection, as well as in cultured astrocytes following repeated morphine treatment [71]. One mechanism by which heroin may impact TSP-1 expression is through increased oxidative stress given that chronic heroin exposure induces a state of oxidative stress in human abusers [72] and also in cultured cortical neurons [73,74]. Moreover, cultured primary astrocytes reduce TSP-1 gene expression under increased oxidative stress conditions, which is prevented by NAC [75]. ...
Both clinical and preclinical studies indicate that adaptations in corticostriatal neurotransmission underlie heroin relapse vulnerability. In animal models, heroin self-administration and extinction produce linked molecular and cellular adaptations in both astrocytes and neurons in the nucleus accumbens (NA) core that are required for cued relapse. For example, decreased expression of the glutamate transporter GLT-1 and reduced association of perisynaptic astrocytic processes with NAcore synapses allow glutamate overflow from prelimbic (PrL) cortical terminals to engage synaptic and structural plasticity in NAcore medium spiny neurons. Importantly, normalizing heroin-induced GLT-1 downregulation prevents glutamate overflow, medium spiny neuron plasticity, and relapse. Surprisingly, little is known about heroin-induced alterations in cortical astroglia and their interaction with neurons. Here we show that heroin SA followed by extinction leads to increased astrocyte complexity and association with synaptic markers in the PrL cortex in male Sprague-Dawley rats. Enhanced astroglial complexity and synaptic interaction were reversed during extinction by repeated treatment with N-acetylcysteine (NAC), an antioxidant drug previously shown to inhibit heroin seeking. We also show that dendritic spines of PrL cortical neurons projecting to the NAcore are enlarged, yet the density of spines is decreased, after extinction from heroin SA. Repeated NAC treatment prevented the decrease in spine density but not dendritic spine expansion. These results reveal circuit-level adaptations in cortical dendritic spine morphology that are related to heroin-induced alterations in astrocyte complexity and association at synapses and demonstrate that NAC reverses cortical heroin-induced adaptations in multiple cell types.
... Studies have indicated drugs such as cocaine, opiates, and alcohol induce oxidative stress, which contributes to cytotoxicity in different organs [9- 11]. In this state, mitochondrial dysfunction and elevated mitochondrial reactive oxygen species accelerate cell death [12,13]. Oxidative stress and increase of inflammatory cytokines in addicted subjects cause accumulation of toxic agents in the body, which has negative effects on the vascular, pulmonary, and nervous systems [14,15]. ...
Both heroin abuse and early life stress (ELS) affect the immune system and the hypothalamic-pituitary-adrenal (HPA) axis. Additionally, accelerated aging due to mild inflammation has been indicated in these conditions. The present study aims to compare plasma levels of apoptosis markers, inflammatory markers, and stress hormones during early heroin abstinence period. Thirty-one individuals with heroin/opioid use disorder who had heroin-ELS and 26 of their siblings who were not abusing substances (ELS), and 32 individuals with heroin/opioid use disorder without a history of ELS (heroin-no ELS) were included in the study. The levels of interleukin-6, C-reactive protein, erythrocyte sedimentation rate, albumin, alanine transaminase, aspartate transaminase, and white blood cell count were assessed as the inflammatory and biochemistry markers. Also, apoptosis markers including tumor necrosis factor (TNF)-related weak inducer of apoptosis, TNF-related apoptosis-inducing ligand, soluble tumor necrosis factor receptor type I as apoptosis markers were detected by enzyme-linked immunosorbent assay. ELS was simultaneously evaluated using the Childhood Trauma Questionnaire, Minnesota Multiphasic Personality Inventory, and beck depression inventory scales. Besides, heroin craving was assessed by Daily Drinking/Drug Questionnaire score in individuals with heroin use disorder. This is the first study to evaluate the inflammatory, stress, and apoptosis markers during heroin abstinence, supporting the association between ELS and peripheral pro-inflammatory markers' levels and HPA axis.
... Additionally, using a sequential heroin and cocaine self-administration paradigm, similar levels of glutamatergic neuronal activation were found following exposure to heroin-or cocaine-associated cues (Rubio et al. 2018) and methadone maintenance reduces cocaine-induced increases in mu-opioid receptor expression in the nucleus accumbens (Leri et al. 2006). In support of synergistic effects, sequential application of heroin and cocaine directly to cortical neurons induces greater neurotoxicity compared to exposure to either drug alone (Cunha-Oliveira et al. 2010). ...
Rationale
Comorbid use of heroin and cocaine is highly prevalent among drug users and can greatly increase addiction risk. Nonetheless, little is known regarding how a multi-drug history impacts motivation and cue responsivity to individual drugs.
Objective
We used behavioral-economic procedures to examine motivation to maintain drug consumption and tests of drug-seeking to drug-associated cues to assess sensitivity to heroin and cocaine-associated cues in rats that had a self-administration history of heroin, cocaine, or both drugs.
Results
Unexpectedly, we found that groups with a polydrug history of heroin and cocaine did not have higher levels of motivation or cue-induced reinstatement of drug-seeking for either cocaine or heroin compared to single drug groups. Nonetheless, we did find drug-specific differences in both economic price and cue sensitivity. Specifically, demand elasticity was lower for cocaine compared to heroin in animals with a single drug history, but not with polydrug groups. In addition, cocaine demand was predictive of the degree of cue-induced reinstatement of drug-seeking for cocaine following extinction, whereas heroin demand was predictive of the degree of reactivity to a heroin-associated cue. Furthermore, although cue reactivity following the initial self-administration phase did not differ across cues and drug history, reactivity to both heroin and cocaine cues was greater during subsequent heroin use compared to cocaine use, and this enhanced reactivity to heroin cues persisted during forced abstinence.
Conclusions
These results indicate that there is a greater motivation to maintain cocaine consumption, but higher sensitivity to drug-associated cues with a history of heroin use, suggesting that cocaine and heroin may drive continued drug use through different behavioral processes.
... Opioids induce direct and indirect adaptations in the peripheral and central immune systems [141] with a clear relationship between opioid dependence and inflammatory processes [142]. Opioids, such as morphine and heroin, act directly on macrophages and lymphocytes, which produce changes in the CNS, resulting in neurotoxicity [143][144][145]. Preclinical models show that chronic morphine treatment increases proinflammatory cytokine levels and overactivates the glia [146,147]. ...
... Recently, chemical interactions between heroin (Her) or its metabolite morphine (Mor) and cocaine (Coc) were described, resulting in the formation of strong adducts. (10) Cocaine is a psychostimulant drug with sympathomimetic properties that is widely abused. In the central nervous system, cocaine interacts with monoaminergic systems, which mediate many of the drugs effects. ...
World Health Organisation defines Drug Abuse as the harmful or hazardous use of psychoactive substances, including alcohol and illicit drugs. Enough is enough. Let us try to stop the drug abuse and addiction by improving the mental health conditions. Tempting situations and impulsive decisions will ruin the personality. Drug addiction is a complex but treatable brain disease.
Listening the children and youth is the first step to help them to grow healthy and safe.
Clinical depression can be a killer. Researchers say more than 18,000 people who take their lives each year in the United States suffer from severe depression. When a loved one dies, a marriage ends, a job promotion doesn't come through, or a tear-jerker movie wrenches at your heartstrings. Suffering from clinical depression- a medical disorder (just like heart disease, diabetes or high blood pressure) that can affect both your behavior and physical health. Left untreated, depression can wreak havoc on your life. In fact, only heart disease results in more days spent confined to bed, and only arthritis is blamed for more chronic pain. Women who suffer from depression twice as often as men are most likely to try snacking, shopping and having a heart-to-heart talk with a friend. Men, on the other hand, more frequently seek distracting, pleasurable activities-like sex- to zap depression. And males are far more likely than women to turn to potentially dangerous behaviors to alter their moods, including abusing drugs and alcohol. The problem is, recreational drugs and alcohol not only don't work, but researchers have concluded they can actually cause- as well as worsen-depression. (1)Drug abuse is defined as the manipulative drug-seeking behavior or the compulsive use of drugs for non-medical purposes, despite harmful side-effects.
Some people suffer from emotional problems like anxiety, tension, fear, loneliness, etc., leading to neuroses. The drugs which primarily affect mental processes to improve moods are called psychoactive drugs and, hence, are classified under CNS stimulants. Neurosis and psychosis are mental illnesses which are associated with psychological disorders involving the brain. A prolonged CNS stimulation always results in depression
... Heroin use may trigger numerous forms of synaptic plasticity in the brain reward regions, and reduce inefficient and redundant neurons for acquiring sensitization toward addiction-related cues 28 . The neurotoxic effects of heroin are involved in loss of gray matter and white matter, cognition, neuronal apoptosis, synaptic defects, depression of neurogenesis, and so on [29][30][31][32][33][34] . The number of synapses, dendritic spines density, and membrane resistance of VTA dopaminergic neurons could be profoundly affected by chronic morphine use 35,36 . ...
The reward system plays a vital role in drug addiction. The purpose of this study is to investigate the structural connectivity characteristics and driving-control subnetwork patterns of reward circuits in heroin abusers and assess the genetic modulation on the reward network. We first defined the reward network based on systematic literature review, and built the reward network based on diffusion tensor imaging data of 78 heroin abusers (HAs) and 79 healthy controls (HCs) using structural connectomics. Then we assessed genetic factors that might modulate changes in the reward network by performing imaging-genetic screening for 22 addiction-related polymorphisms. The genetic association was validated by performing genetic associations (1032 HAs and 2863 HCs) and expanded-variant analysis. Finally, we estimated the association between these genetic variations, reward network, and clinical performance. We found that HAs had widespread deficiencies in the structural connectivity of the reward circuit (center in VTA-linked connections), which correlated with cognition deficiency. The disruptions synchronously were shown on the reward driving system and reward control system. GABRA2 rs279858-linked variants might be a key genetic modulator for heroin vulnerability by affecting the connections of reward network and cognition. The role of the reward network connections that mediates the effects of rs279858 on cognition would be disrupted by heroin addiction. These findings provide new insights into the neurocircuitry and genetic mechanisms of addiction.
... Here we also observed a cocaine-mediated reduction in F(Ratio) during T-type calcium channels activation, suggesting the existence of compensatory mechanisms in VB neurons in order to manage higher [Ca 2+ ] i levels through the activation of these channels. Indeed, acute cocaine has been shown to enhance basal [Ca 2+ ] i in cortical neurons [37], while repeated cocaine exposure led to a deregulation of [Ca 2+ ] i homeostasis in nucleus accumbens neurons, that reduced calcium entry [38]. Acute cocaine administration can increase the expression of endoplasmic reticulum stress proteins in striatal neurons [39]. ...
The ventrobasal (VB) thalamus relay nucleus processes information from rodents' whiskers, projecting to somatosensory cortex. Cocaine and methylphenidate (MPH) have been described to differentially alter intrinsic properties of, and spontaneous GABAergic input to, VB neurons. Here we studied using bis-fura 2 ratiometric fluorescence the effects of cocaine and MPH on intracellular [Ca(2+)] dynamics at the soma and dendrites of VB neurons. Cocaine increased baseline fluorescence in VB somatic and dendritic compartments. Peak and areas of fluorescence amplitudes were reduced by cocaine binge treatment in somas and dendrites at different holding potentials. MPH binge treatment did not alter ratiometric fluorescence at either somatic or dendritic levels. These novel cocaine-mediated blunting effects on intracellular [Ca(2+)] might account for alterations in the capacity of thalamocortical neurons to maintain gamma band oscillations, as well as their ability to integrate synaptic afferents.
... A number of studies have demonstrated that opioids such as morphine and heroin affect the immune system either directly through acting on macrophages and lymphocytes peripherally or indirectly by eliciting changes in the CNS that may result in neurotoxicity (Cunha-Oliveira et al., 2010;Fecho et al., 1996;McCarthy et al., 2001;Nelson et al., 2010;Sacerdote, 2006). Chronic morphine treatment to a rodent neuropathic model led to substantial increases in proinflammatory cytokine levels (e.g., IL-1b, TNF-a, IL-6) as well as glial cell overactivation (Raghavendra et al., 2003), an observation that was supported by reports of significant elevations in cytokine expression in the brain of an animal model of opioid dependence (Chen et al., 2012). ...
Over the years, drug addiction has proven to be a perplexing conundrum for scientists. In attempts to decipher the components of the puzzle, multiple theories of addiction have been proposed. While these theories have assisted in providing essential fundamental information, current research recommends that a new theory needs to be presented taking into consideration the results of recent developments in the fields of neuroimmunology, genetics, and neuropsychiatry. After extensively examining the published literature, we propose in this review that neuroinflammation and hypothalamic functioning strongly underpin addictive behavior.To substantiate this notion, we typed the search-string "cocaine addiction, hypothalamus, and inflammation" into PubMed and Google Scholar. 50 and 1280 results were obtained in PubMed and Google Scholar, respectively. All article abstracts were perused for relevance to this review and 177 articles were used. Recent studies have purported that both acute and chronic psychostimulant use can activate specific components of the innate immune system. Findings such as these provide the scientific evidence supporting a hypothesis that includes a role for the innate immune system and inflammation in addictive behavior. However, the pathophysiological mechanisms by which they mediate the development of addiction have not been clearly delineated. The following review particularly focuses on the lateral hypothalamus and its functioning in satiety, and how inflammatory processes in the brain may contribute to addiction.
... analyses done over the past decade have increased our understanding of drug addiction. Opioid-induced degeneration in the cortical (Cunha-Oliveira et al., 2010) and dopaminergic neurons has been reported (Chu et al., 2008;Sklair-Tavron et al., 1996). These damaged brain cells might cause the dysfunction of neuronal plasticity in heroin addicts. ...
Background:
Long-term heroin addicts have low plasma brain-derived neurotrophic factor (BDNF) levels. However, the mechanisms and effects of systemic disturbances of BDNF caused by heroin remain unclear.
Objective:
Blood platelet might be a source of neurotrophic factors like BDNF and transforming growth factor (TGF)-β1. Thus, we investigated the effects of heroin on platelets, BDNF and TGF-β1, the association between blood platelets, BDNF, TGF-β1, and executive function in long-term heroin addicts.
Methods:
We enrolled 170 heroin addicts and 141 healthy controls. We measured their plasma BDNF and TGF-β1 levels and counted their platelets, red and white blood cells. The Wisconsin Card Sorting Test (WCST) was used to assess their executive function.
Results:
Plasma BDNF and TGF-β1 levels were significantly downregulated in long-term heroin addicts. BDNF, TGF-β1, and platelet levels were lower in patients who had used heroin for more than 6 years than in those who had used it for less than 6 years. Lower plasma BDNF and TGF-β1 levels were highly correlated with the changes in platelet counts. In the WCST, the number of trials needed to complete the first category were negatively associated with platelet counts and BDNF levels.
Conclusions:
In long-term heroin addicts, lower platelet counts contributed to lower plasma BDNF and TGF-β1 levels, which, in turn, contributed to the disruption of executive function after long-term heroin use. Neurotrophic- and platelet-protective agents might provide a useful research focus for heroin addiction therapy.
... Furthermore, Lepsch, Planeta, and Scavone (2015), using primary mesencephalic and striatal cultures from rat embryonic brain, described an inhibition of neurite prolongation and apoptosis in both cell cultures, demonstrated by an increase in DNA fragmentation, a decrease in microtubule associated protein 2, and/or neuronal nucleus protein staining. Cocaine also induced mitochondrial dysfunction and activated the mitochondria-dependent intrinsic caspase cascade in cortical neurons (Cunha-Oliveira et al., 2010. ...
Repeated exposure to cocaine can induce long-lasting effects in the brain that lead to changes in morphology or function of cellular components, including mitochondria, inhibition of neurite extension, reduction in dilation of the endoplasmic reticulum and abnormal lysosomal proteolysis. Moreover, it produces enduring neuroadaptations in the mesocorticolimbic dopamine system that has been related to drug craving. Several studies have demonstrated neural and systemic toxic effects of cocaine in humans and animals, as well as persistent alterations in intracellular signaling.
... The interaction of multiple drugs can lead to further oxidative damage [26]. For example, the combination of cocaine and opioids ('speedball') accentuates mitochondrial dysfunction [27], and co-abuse of cocaine and ethanol (produces an active metabolite, cocaethylene) resulted in increased ROS generation [28]. ...
Drug-addiction may trigger early onset of age-related disease, due to drug-induced multi-system toxicity and perilous lifestyle, which remains mostly undetected and untreated. We present the literature on pathophysiological processes that may hasten aging and its relevance to addiction, including: oxidative stress and cellular aging, inflammation in periphery and brain, decline in brain volume and function, and early onset of cardiac, cerebrovascular, kidney, and liver disease. Timely detection of accelerated aging in addiction is crucial for the prevention of premature morbidity and mortality.
... The neurotoxic effects of drugs of abuse are commonly associated with oxidative stress, mitochondrial dysfunction, apoptosis and inhibition of neurogenesis, in addition to other mechanisms. 3,4 Adolescence is a critical phase for cerebral development. Exposure to addictive substances during this phase leads to various alterations in brain functions that can be translated into functional consequences throughout life. ...
p class="abstract"> Background: Adolescence is a critical period for cerebral development. Exposure to addictive substances during this phase leads to various alterations in brain functions that persist into adulthood. The present study was designed to study the neurotoxic effects of tramadol and cannabis, alone and in combination, in adolescent male albino rats by studying their behavioral, biochemical, and histopathological neurotoxic effects and their long–term consequences after withdrawal.
Methods: For this purpose, 132 adolescent male albino rats were divided into 5 groups (22 rats/ group). Group I (negative control), received only regular diet and tap water to measure the basic parameters, Group II (positive control; IIA&IIB); IIA, gavaged with normal saline. IIB, gavaged with olive oil. Group III (tramadol), gavaged with tramadol (42, 84 and 168 mg/kg/day) in the first, second and third ten days of the study respectively. Group IV (cannabis), gavaged with hashish extract (92, 184 and 368 mg/kg/day) in the first, second and third ten days of the study respectively. Group V (tramadol+cannabis), gavaged with tramadol and hashish extract in the same doses as Group III&IV. By the end of the first month, the half number of rats was subjected to performing behavior tests. Specimens from the brain were taken for performing biochemical and histopathological studies. All remaining rats were held for another 4 weeks non–dosing spontaneous recovery period after withdrawal of the treatment and were evaluated again by the same previous parameters.
Results: Abuse of tramadol or cannabis, alone and in combination, caused antidepressant effect (sucrose preference test), impaired spatial memory (Morris water maze), elevated serotonin levels in the cerebral cortex and hippocampus, induced oxidative stress (significantly elevated malondialdehyde level and reduced catalase activity) as well as deleteriously altered brain histopathology and marked increase in brain Caspase–3 expression. However, abuse of both tramadol and cannabis conferred more antidepressant effect but more neurotoxic effect. After withdrawal, the antidepressant effect was reversed, no improvement of the spatial memory, marked depletion of 5–HT, more improvement in antioxidants and apoptotic markers and incomplete regression of brain histopathological alteration resulted.
Conclusions: Abuse of tramadol and cannabis, alone and in combination, induced neurotoxicity which proved behaviorally, biochemically and histopathologically. </p
... Several drug identification methods, clinical researches including volunteers with cocaine-heroin addicts, and animal experiments were conducted to clarify the pharmacokinetic effect mechanisms of speedball in detail [12][13][14][15][16]. There are also some studies reported in the literature explaining the neuropsychobiologic way of actuation of these drugs [17][18][19][20]. ...
Abstract
Background
The “speedball”, which generally defines the simultaneous use of cocaine and heroin, is a street language term and refers to multiple drug intakes. It is also difficult to discriminate the speedball abuser from others. Recently, speedball abuse listed in international drug reports is increasing not only among famous people but also in community.
In this study, a speedball case has been demonstrated with the toxicological findings in the serum sample for the first time in Turkey.
Case report
A married 33 years old woman was admitted to the Emergency Room at the Cerrahpaşa Medical Faculty, with various complaints. There were no obvious signs of an acute intoxication, which may caused by a sympathomimetic agent. After the clinical examination, toxicological analysis was requested from the Forensic Toxicology Laboratory at the Institute of Forensic Sciences. Serum analyses was performed by GC-MS and the concentrations at the time of administration were determined as 330,0 ng/mL and 11,23 ng/mL for cocaine and heroin, respectively along with qualitatively determined and 6-MAM.
Conclusion
Since it is known that the combined drug abuse may increase the effect of each other and cause fatal consequences, it is intended to draw attention to approach during emergency treatments. Multidisciplinary approach between clinicians and toxicology experts will be in the patient's best interest in the case of speedball abuse.
... These color changes were from blue (oxidized, resazurin) to purple/pink (reduced, resorufin) and then to colorless (hydroresorufin). The optical density or absorbance at 600 nm was determined as described by Oliveira et al. (2010) using a microplate reader (PerkinElmer, MO, USA), and the numerical values were converted into 7 levels in response to the extent of color changes. For this assay, "0" represents no change (dark blue), and "1-6" represent positive reactions of increasing color intensities. ...
Biofertilizers can help improve soil quality, promote crop growth, and sustain soil health. The photosynthetic bacterium Rhodopseudomonas palustris strain PS3 (hereafter, PS3), which was isolated from Taiwanese paddy soil, can not only exert beneficial effects on plant growth but also enhance the efficiency of nutrient uptake from applied fertilizer. To produce this elite microbial isolate for practical use, product development and formulation are needed to permit the maintenance of the high quality of the inoculant during storage. The aim of this study was to select a suitable formulation that improves the survival and maintains the beneficial effects of the PS3 inoculant. Six additives (alginate, polyethylene glycol [PEG], polyvinylpyrrolidone-40 [PVP], glycerol, glucose, and horticultural oil) were used in liquid-based formulations, and their capacities for maintaining PS3 cell viability during storage in low, medium, and high temperature ranges were evaluated. Horticultural oil (0.5 %) was chosen as a potential additive because it could maintain a relatively high population and conferred greater microbial vitality under various storage conditions. Furthermore, the growth-promoting effects exerted on Chinese cabbage by the formulated inoculants were significantly greater than those of the unformulated treatments. The fresh and dry weights of the shoots were significantly increased, by 10–27 and 22–40 %, respectively. Horticultural oil is considered a safe, low-cost, and easy-to-process material, and this formulation would facilitate the practical use of strain PS3 in agriculture.
Substance use has been intertwined with human history for millennia. Throughout the ages, people have consumed various substances for medicinal, spiritual, and recreational reasons, although occasional use differs significantly from substance use disorders (SUDs). Exposure to lifetime stressors constitutes a significant risk factor for both psychiatric disorders and SUD development and relapse. Indeed, hypothalamic–pituitary–adrenal (HPA) axis modulation, alterations in neuroanatomical and neurotransmitter systems, as well as neuroinflammation are common features of stress-related mood disorders and SUDs. In this mini-review, we will explore how stress exposure influences the SUDs' neurobiological basis on different scales—from large neural circuitries to specific molecular mechanisms—and discuss novel targets for potential treatments.
Introduction/Aim
The study examines how chronic resveratrol administration affects behavioral and neurochemical changes caused by Lorazepam (LZP), a classical anti-anxiety medicine associated with neurodegenerative and neurological problems.
Method
Forty male rats were placed into four groups: a control group receiving 1% Tween 80, the LZP group receiving 2 mg/kg/day, the Resveratrol group receiving 50 mg/kg/day, and the LZP plus resveratrol group receiving the same doses of LZP and Resveratrol. Oral therapy was given daily for 6 weeks. The animals were euthanized after open field and Y maze behavioral tests. In specific brain regions, neurochemical analyses were performed on GABA, glutamic acid, monoamines (norepinephrine, dopamine, and serotonin) and their metabolites, DNA fragmentation (8-hydroxy-2–deoxyguanosine or 8-HdG), brain-derived neurotrophic factor (BDNF), and Ca-ATPase.
Results
Resveratrol therapy improved GABA, glutamic acid, monoamines, and their metabolites in the cerebral cortex, hippocampus, and striatum. Additionally, it reduced DNA fragmentation (8- HdG) and counteracted LZP-induced Ca-ATPase downregulation at a significant level (p < 0.05). Resveratrol also reversed LZP-induced behavioral changes in the Y maze and open field tests.
Conclusion
Resveratrol has anxiolytic-like actions like benzodiazepines and neuroprotective capabilities against LZP-induced adverse effects.
Substance use disorders (SUD) can lead to serious health problems, and there is a great interest in developing new treatment methods to alleviate the impact of substance abuse. In recent years, the ketogenic diet (KD) has shown therapeutic benefits as a dietary therapy in a variety of neurological disorders. Recent studies suggest that KD can compensate for the glucose metabolism disorders caused by alcohol use disorder by increasing ketone metabolism, thereby reducing withdrawal symptoms and indicating the therapeutic potential of KD in SUD. Additionally, SUD often accompanies increased sugar intake, involving neural circuits and altered neuroplasticity similar to substance addiction, which may induce cross-sensitization and increased use of other abused substances. Reducing carbohydrate intake through KD may have a positive effect on this. Finally, SUD is often associated with mitochondrial damage, oxidative stress, inflammation, glia dysfunction, and gut microbial disorders, while KD may potentially reverse these abnormalities and serve a therapeutic role. Although there is much indirect evidence that KD has a positive effect on SUD, the small number of relevant studies and the fact that KD leads to side effects such as metabolic abnormalities, increased risk of malnutrition and gastrointestinal symptoms have led to the limitation of KD in the treatment of SUD. Here, we described the organismal disorders caused by SUD and the possible positive effects of KD, aiming to provide potential therapeutic directions for SUD.
The Habenula is increasingly being investigated in addiction. Reduced volumes of other relevant brain regions in addiction, such as nucleus accumbens, globus pallidus and hypothalamus have been reported. Reduced volumes of the habenula as well as reduced neuronal cell count in the habenula have also been reported in mood disorders and an overlap between mood disorders and addiction is clinically widely recognized. Thus, our aim was to investigate possible volume and neuronal cell count differences in heroin addicts compared to healthy controls. Volumes of the medial (MHB) and lateral habenula (LHB) in heroin addicts (n = 12) and healthy controls (n = 12) were assessed by morphometry of 20 µm serial whole brain sections. Total brain volume was larger in the heroin group (mean 1466.6 ± 58.5 cm3 vs. mean 1331.5 ± 98.8 cm3), possibly because the heroin group was about 15 years younger (p = 0.001). Despite larger mean whole brain volume, the mean relative volume of the MHB was smaller than in healthy non-addicted controls (6.94 ± 2.38 × 10–6 vs.10.64 ± 3.22 × 10−6; p = 0.004). A similar finding was observed regarding relative volumes of the LHB (46.62 ± 10.90 × 10−6 vs. 63.05 ± 16.42 × 10−6p = 0.009). In parallel, neuronal cell numbers were reduced in the MHB of heroin-addicted subjects (395,966 ± 184,178 vs. 644,149 ± 131,140; p < 0.001). These findings were not significantly confounded by age and duration of autolysis. Our results provide further evidence for brain-structural deficits in heroin addiction.
Clinical research has demonstrated the efficacy of injectable opioid treatment for long-term, treatment-refractory opioid-dependent patients. It has been hypothesized that compulsive drug use is particularly associated with neuroplasticity changes in the networks corresponding to withdrawal/negative affect and preoccupation/antici-pation rather than binge/intoxication. However, as yet, no study has investigated the effect of long-term opioid treatment on key regions within these networks. Magnetic resonance imaging (MRI) was used to assess brain volumes changes during long-term (approximately 9 years) injectable opioid agonist treatment with diacetylmorphine (DAM) in 22 patients with opioid use disorder. Voxel-based morphometry was applied to detect volumetric changes within the networks of binge/intoxication (ventral/dorsal striatum, globus pallidus and thalamus), withdrawal/negative affect (amygdala and ventral striatum) and preoccupation/anticipation (hippocampus, orbitofrontal and anterior cingulate cortex). The relationships between significant volume changes and features of opioid use disorder were tested using Pearson correlation. Long-term opioid agonist treatment was associated with the enlargement of the right caudate nucleus, which was related to the duration of opioid use disorder. In contrast, reduced volume in the right amygdala, anterior cingulate cortex and orbitofrontal cortex were found that were related to opioid dose, onset of opioid consumption and state anxiety. These findings suggest that long-term opioid agonist treatment is related to structural changes in key brain regions underlying binge/intox-ication, withdrawal/negative affect and preoccupation/anticipation, suggesting sustained interaction between these systems. K E Y W O R D S anticipation, binge, brain volume changes, long-term opioid treatment, voxel-based morphometry, withdrawal
Tramadol is a common analgesic, frequently used for relieving moderate or severe pain and widely used to delay ejaculation. However, repeated large doses have several adverse effects, especially on the brain tissue. So, this study was designed to assess the potentially deleterious effects of chronic administration of tramadol on principal fields of the hippocampus in adult and juvenile male albino mice. Thirty swiss male albino mice were divided equally into three groups: Group Ia (control adult) 3 months old, Group Ib (control juvenile) 3-week postnatal mice, Group II (tramadol treated adult mice) and Group III (tramadol treated juvenile mice). Both treated groups received tramadol tablets dissolved in water in a dose of 40mg/kg for 1 month by gastric tube. Tramadol treated groups showed degenerative changes in dentate gyrus (DG) granule cells, pyramidal neurons of CA1and CA3 fields in the form of electron-dense or rarified cytoplasm, dilated rER and mitochondrial changes. Additionally, immunohistochemical results revealed significantly increased in caspase 3 positive cells in different hippocampal principal fields. Astrogliosis and microgliosis were proved by the increased immunoreactivity of astrocytes to glial fibrillary acidic protein (GFAP) and microglia to CD68. Morphometric findings showed a significant reduction of both surface area of granule and pyramidal cells, and in thickness of DG, CA1, CA3 layers. Moreover, most of these morphological changes were aggravated in the juvenile-treated group. So, it can be concluded that tramadol abuse can induce an altered morphological change on the principal fields of the hippocampus in adult and juvenile mice.
Speedball (heroin + cocaine) is a prevalent drug combination among intravenous drug users. Although its use is generally discussed to be a function of changes in the rewarding effects of either or both drugs, changes in the aversive effects of either drug may also be impacted (weakened) by the combination. To address this latter possibility and its potential role in the use of speedball, the present studies examined the interaction of cocaine and heroin in taste avoidance conditioning. In Experiment 1, male Sprague-Dawley rats were given access to a novel saccharin solution and then injected with either vehicle or heroin (3.2 mg/kg, IP) followed immediately by various doses of cocaine (10, 18 or 32 mg/kg, SC). At the two lowest doses of cocaine, only animals injected with the drug combination (H + C) displayed a taste avoidance relative to control subjects (taste avoidance was induced with both the combination and the high dose of cocaine). At no dose did animals injected with the combination of heroin and cocaine drink less than animals injected with cocaine alone. In Experiment 2, male Sprague-Dawley rats were similarly treated but injected with vehicle or cocaine (10 mg/kg) followed by injections of various doses of heroin (1.8, 3.2, 5.6 or 10 mg/kg). At the three highest doses of heroin, only animals injected with the drug combination (C + H) displayed significant avoidance relative to control subjects (no avoidance was evident with the combination of cocaine and the low dose of heroin). At no dose did animals injected with the combination of cocaine and heroin drink less than animals injected with heroin alone. Together, these results suggest that the aversive effects of heroin and cocaine are not attenuated by co-administration by cocaine and heroin, respectively. The importance of this for the use of speedball was discussed.
Simultaneous administration of psychostimulants and opioids is a major drug abuse problem worldwide. The combination of psychostimulants and opioids produces more serious effects than either drug alone and is responsible for numerous deaths. In recent years, owing to its increased use, methamphetamine (METH), a psychostimulant, has become a popular choice for use in combination with opioids, especially heroin. However, little is known about the neurotoxicity of METH/heroin combination. The aims of this study were to evaluate whether METH/heroin combination was more neurotoxic than either drug alone and analyze the possible neurotoxic mechanisms using rat pheochromocytoma (PC12) cells. Our data showed that METH/heroin combination exhibited a significant decrease in cell viability than either drug alone, and the coefficient of drug interaction (CDI) indicated that the combination appeared to produce synergistic effects. Further studies showed that METH/heroin combination induced apoptosis and decreased the mitochondrial potential significantly, compared to either drug alone. This was demonstrated by a significant decrease in the expression of Bcl-2 and an increase in expression of Bax, accompanied by increase in the activities of caspase-3 and caspase-9. These results suggest that the combination of METH and heroin is more neurotoxic than either drug alone, and it induces apoptosis via the mitochondrial apoptotic pathway.
Eleven different complexes were found between heroin (or its main metabolite, morphine) and cocaine (or its main metabolite, ecgonine methyl ester) in a B3LYP computational study. Ten of these complexes display intermolecular hydrogen bonds, while only one is a stacked structure. All of them display positive complexation energies in the gas phase that turn into negative values in aqueous solution according to PCM calculations. Complexation energies become even more negative when explicit solvation water molecules are taken into account. Thus, complexes between these compounds could be present in biological media. The electron density of the 11 complexes was analysed within the QTAIM framework distinguishing three terms for every atomic property: (i) geometry distortion; (ii) BSSE estimated by extending the counterpoise (CP) method; and (iii) binding. We notice that: (i) geometry distortion effects are basically localised in the atoms involved in intermolecular bonds (interaction sites); (ii) counterpoise corrections for atomic properties are very small; and (iii) binding CP-corrected effects spread throughout the whole complex. The later are the most significant and indicate the important role played by hydrogens outside the interaction sites as electron density sources and sinks in complex formation.
Excited delirium syndrome (ExDS) is a term used to describe a clinical condition characterized by bizarre and aggressive behaviour, commonly associated with the use of psychoactive compounds, especially cocaine. The pathophysiology of ExDS is complex and not yet fully understood. In addition to a central dopamine hypothesis, other mechanisms are thought to be involved in cocaine-related ExDS, such as increased reactive oxygen species production by the family of the NADPH oxidase NOX enzymes. In this review, we will summarize current knowledge on the crucial contribution of brain NADPH oxidase derived oxidative stress in the development of cocaine-induced ExDS. Data from animal models as well as human evidence will be discussed.
Tramadol abuse is one of the most frequent health problems in Egypt and worldwide. In most cases, tramadol abused by men face a problem with premature ejaculation. Tramadol like other opioids induces a decrease in plasma antioxidant levels, which may reflect a failure of the antioxidant defense mechanism against oxidative damage. The present work aimed to study the possible deleterious effects of oral administration of tramadol on brain and lung tissues in rats. Twenty adult male albino rats were divided into two groups; a control administered with normal saline and tramadol-treated (40 mg/kg b.w.) group for 20 successive days. At the end of experimental period, blood was collected and specimens from brains and lungs were taken for histopathological and molecular studies. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) activities were measured in serum of control and tramadol-treated groups. Brain and lung specimens were histopathological evaluated using light microscopy. The expression levels of apoptotic related genes; Bcl-2, Bax and Caspase-3 were study in brain and lung tissues using RT-PCR analysis. We recorded a significant increase MDA level, while antioxidant enzymes; GSH, SOD and CAT were significantly decreased after tramadol-treatment. The obtained results revealed that tramadol induced a remarkable histomorphological changes in rats’ brains (cerebral cortex and hippocampus) and severe histopathological changes in rats' lung when compared to that of control. On molecular level, the expression of the pro-apoptotic Bax and Caspase-3 showed a significant increase whereas the anti-apoptotic Bcl-2 decreased markedly indicating that tramadol is harmful at cellular level and can induce apoptotic changes in brain tissues. Our data confirmed the risk of increased oxidative stress, neuronal and pulmonary damage due to tramadol abuse. Although tramadol is reported to be effective in pain management, its toxicity should be kept in mind.
Crack cocaine has a high potential to induce cocaine addiction and its smoke contains cocaine's pyrolysis product anhydroecgonine methyl ester (AEME), a partial agonist at M1- and M3-muscarinic acetylcholine receptor and an antagonist at the remaining subtypes. No reports have assessed AEME's role in addiction. Adult male Wistar rats were intraperitoneally administered with saline, 3mg/kg AEME, 15mg/kg cocaine, or a cocaine-AEME combination on every other day during a period of 9 days. After a 7-days withdrawal period, a challenge injection of the respective drugs was performed on the 17th day. The locomotor activity was evaluated on days 1, 3, 5, 7, 9 and 17, as well as dopamine levels (9th day) and dopaminergic receptors proteins (D1R and D2R on the 17th day) in the caudate-putamen (CPu) and nucleus accumbens (NAc). AEME was not able to induce the expression of behavioral sensitization, but it substantially potentiates cocaine-effects, with cocaine-AEME combination presenting higher expression than cocaine alone. An increase in the dopamine levels in the CPu in all non-saline groups was observed, with the highest levels in the cocaine-AEME group. There was a decrease in D1R protein level in this brain region only for cocaine and cocaine-AEME groups. In the NAc, an increase in the dopamine levels was only observed for cocaine and cocaine-AEME groups, with no changes in both D1R and D2R protein levels. These behavioral and neurochemical data indicate that AEME alone does not elicit behavioral sensitization but it significantly potentiates cocaine effects when co-administered, resulting in dopamine increase in CPu and NAc, brain regions where dopamine release is mediated by cholinergic activity.
Cocaine is extensively used as a psychostimulant among subjects at different ages worldwide. Cocaine causes neuronal dysfunction and, consequently, negatively affects human behavior and decreases life quality severely. Cocaine acts through diverse mechanisms, including mitochondrial impairment and activation of cell signaling pathways associated to stress response. There is some controversy regarding the effect of cocaine in inducing cell death through apoptosis in different experimental models. The aim of the present work is to discuss data associated to the mitochondrial consequences of cocaine exposure of mammalian cells in several experimental models from in vitro to in vivo, including postmortem human tissue analyses. Furthermore, future directions are proposed in order to serve as a suggestive guide in relation to the next steps towards the complete elucidation of the mechanisms of toxicity elicited by cocaine upon mitochondria of neuronal cells.
Patients with acute cocaine poisoning present with life-threatening symptoms involving several organ systems. While the effects of cocaine are myriad, they are the result of a limited number of cocaine-protein interactions, including monoamine transporters, neurotransmitter receptors and voltage-gated ion channels. These primary interactions trigger a cascade of events that ultimately produce the clinical effects. The purpose of this article is to review the primary interactions of cocaine and the effects that these interactions trigger. We also describe the progression of symptoms observed in cocaine poisoning as they relate to serum cocaine concentrations.
We investigated the relative importance of heroin and its metabolites in eliciting a behavioral response in mice by studying the relationship between concentrations of heroin, 6-monoacetylmorphine (6MAM), and morphine in brain tissue and the effects on locomotor activity. Low doses (subcutaneous) of heroin (< or =5 micromol/kg) or 6MAM (< or =15 micromol/kg) made the mice run significantly more than mice given equimolar doses of morphine. There were no differences in the response between heroin and 6MAM, although we observed a shift to the left of the dose-response curve for the maximal response of heroin. The behavioral responses were abolished by pretreatment with 1 mg/kg naltrexone. Heroin was detected in brain tissue after injection, but the levels were low and its presence too short-lived to be responsible for the behavioral response observed. The concentration of 6MAM in brain tissue increased shortly after administration of both heroin and 6MAM and the concentration changes during the first hour roughly reflected the changes in locomotor activity. Both the maximal and the total concentration of 6MAM were higher after administration of heroin than after administration of 6MAM itself. The morphine concentration increased slowly after injection and could not explain the immediate behavioral response. In summary, the locomotor activity response after injection of heroin was mediated by 6MAM, which increased shortly after administration. Heroin acted as an effective prodrug. The concentration of morphine was too low to stimulate the immediate response observed but might have an effect on the later part of the heroin-induced behavioral response curve.
Cocaine is a worldwide used drug and its abuse is associated with physical, psychiatric and social problems. The mechanism by which cocaine causes neurological damage is very complex and involves several neurotransmitter systems. For example, cocaine increases extracellular levels of dopamine and free radicals, and modulates several transcription factors. NF-kappaB is a transcription factor that regulates gene expression involved in cellular death. Our aim was to investigate the toxicity and modulation of NF-kappaB activity by cocaine in PC 12 cells. Treatment with cocaine (1 mM) for 24 hours induced DNA fragmentation, cellular membrane rupture and reduction of mitochondrial activity. A decrease in Bcl-2 protein and mRNA levels, and an increase in caspase 3 activity and cleavage were also observed. In addition, cocaine (after 6 hours treatment) activated the p50/p65 subunit of NF-kappaB complex and the pretreatment of the cells with SCH 23390, a D1 receptor antagonist, attenuated the NF-kappaB activation. Inhibition of NF-kappaB activity by using PDTC and Sodium Salicilate increased cell death caused by cocaine. These results suggest that cocaine induces cell death (apoptosis and necrosis) and activates NF-kappaB in PC12 cells. This activation occurs, at least partially, due to activation of D1 receptors and seems to have an anti-apoptotic effect on these cells.
Cocaine abuse during pregnancy has been associated with numerous adverse perinatal outcomes.
The present study was to determine whether prenatal cocaine exposure induced apoptosis and the possible role of Bcl-2 family genes in the programming cell death in fetal rat brain.
Pregnant rats were treated with cocaine subcutaneously (30 & 60 mg/kg/day) from day 15 to 21 of gestation. Then the fetal and maternal brains were isolated.
Cocaine produced a dose-dependent decrease in fetal brain weight and brain/body weight ratio (P<0.05). Apoptotic nuclei in fetal brain were increased from 2.6 +/- 0.1 (control) to 8.1+/- 0.6 (low dose) and 10.4 +/- 0.2% (high dose) (P<0.05). In accordance, cocaine dose dependently increased activities of caspase-3, caspase-8, and caspase-9 (% of control) in the fetal brain by 177%, 155%, 174%, respectively, at 30 mg/kg/day, and by 191%, 176%, 274%, respectively, at 60 mg/kg/day. In contrast, cocaine showed no effect on caspase activities in the maternal brain. Cocaine produced a dose-dependent increase in both Bcl-2 and Bax protein expression in the fetal brain, and increased the ratio of Bax/Bcl-2 at dose of 30 mg/kg/day (P<0.05).
Our study has demonstrated that prenatal cocaine exposure induces apoptosis in the fetal brain, and suggested that up-regulating Bax/Bcl-2 gene expression may be involved in cocaine-induced apoptosis. The increased apoptosis of neuronal cells in the fetal brain is likely to play a key role in cocaine-induced neuronal defects during fetal development.
This article reviews the pharmacokinetics of heroin after intravenous, oral, intranasal, intramuscular and rectal application and after inhalation in humans, with a special focus on heroin maintenance therapy in heroin dependent patients. In heroin maintenance therapy high doses pharmaceutically prepared heroin (up to 1000 mg/day) are prescribed to chronic heroin dependents, who do not respond to conventional interventions such as methadone maintenance treatment. Possible drug-drug interactions with the hydrolysis of heroin into 6-monoacetylmorphine and morphine, the glucuronidation of morphine and interactions with drug transporting proteins are described. Since renal and hepatic impairment is common in the special population of heroin dependent patients, specific attention was paid on the impact of renal and hepatic impairment. Hepatic impairment did not seem to have a clinically relevant effect on the pharmacokinetics of heroin and its metabolites. However, some modest effects of renal impairment have been noted, and therefore control of the creatinine clearance during heroin-assisted treatment seems recommendable.
The pharmacokinetics of cocaine were studied in five subjects with histories of drug abuse who were otherwise healthy. A two-compartment system was used to model the distribution kinetics of the drug. The steady-state volume of distribution averaged 131.8 L or 1.96 L/kg, elimination clearance was 2.10 L/min, and the t 1/2 was 48 minutes. Cocaine concentrations in a hypothetic biophase were estimated to correlate the chronotropic effects of this drug with its pharmacokinetics. The experimentally determined kinetic parameters indicate that the peak chronotropic effect would occur 7.3 minutes after intravenous bolus injection of cocaine, and that biophase cocaine concentrations would initially accelerate the heart rate by 0.3 bpm for each 1 ng/ml. The kinetic analysis also demonstrated that the chronotropic effects of cocaine decline more rapidly than either plasma levels or biophase concentrations. This progressive attenuation in intensity of the chronotropic effect of a given biophase cocaine concentration could be modeled as a first-order process and is compatible with either the intervention of homeostatic reflex mechanisms or the phenomenon of acute tolerance.
Although many deaths occur annually from heroin intoxication, the presence of heroin has not been reported in postmortem tissues. Recognizing heroin's susceptibility to rapid chemical and metabolic hydrolysis, extraction procedures were developed for the efficient recovery of heroin, 6-acetylmorphine, and morphine from postmortem tissue utilizing solid-phase extraction coupled with gas chromatography/mass spectrometry. From heroin-related deaths, 21 sets of blood and urine specimens were collected. The mode of death in these cases was categorized as rapid, delayed, or undetermined. Compared with delayed deaths, rapid deaths were characterized by the following trends: higher mean concentrations of 6-acetylmorphine, free morphine, and total opiates in blood; a higher ratio of free morphine concentrations to total opiate concentrations in blood; lower mean concentrations of 6-acetylmorphine and morphine in urine; greater likelihood of 6-acetylmorphine detection in blood; and lesser likelihood of heroin detection in urine. The study also included analysis of multiple tissue specimens from two subjects who died of heroin intoxication. Heroin was identified in urine and injection-site tissue. Concentrations of 6-acetylmorphine in cerebrospinal fluid, spleen, and brain were substantially higher than in blood, liver, lung, and kidney. All specimens were positive for morphine. Heroin metabolites were detected in hair specimens. The identification of heroin and 6-acetylmorphine in biological tissues effectively established the presence of heroin in cases of acute narcotic intoxication. These studies demonstrated that measurement of heroin and its metabolites provides useful information for the differential diagnosis of heroin-related deaths.
Imaging studies have revealed neurochemical and functional changes in the brains of drug-addicted subjects that provide new insights into the mechanisms underlying addiction. Neurochemical studies have shown that large and fast increases in dopamine are associated with the reinforcing effects of drugs of abuse, but also that after chronic drug abuse and during withdrawal, brain dopamine function is markedly decreased and these decreases are associated with dysfunction of prefrontal regions (including orbitofrontal cortex and cingulate gyrus). The changes in brain dopamine function are likely to result in decreased sensitivity to natural reinforcers since dopamine also mediates the reinforcing effects of natural reinforcers and on disruption of frontal cortical functions, such as inhibitory control and salience attribution. Functional imaging studies have shown that during drug intoxication, or during craving, these frontal regions become activated as part of a complex pattern that includes brain circuits involved with reward (nucleus accumbens), motivation (orbitofrontal cortex), memory (amygdala and hippocampus), and cognitive control (prefrontal cortex and cingulate gyrus). Here, we integrate these findings and propose a model that attempts to explain the loss of control and compulsive drug intake that characterize addiction. Specifically, we propose that in drug addiction the value of the drug and drug-related stimuli is enhanced at the expense of other reinforcers. This is a consequence of conditioned learning and of the resetting of reward thresholds as an adaptation to the high levels of stimulation induced by drugs of abuse. In this model, during exposure to the drug or drug-related cues, the memory of the expected reward results in overactivation of the reward and motivation circuits while decreasing the activity in the cognitive control circuit. This contributes to an inability to inhibit the drive to seek and consume the drug and results in compulsive drug intake. This model has implications for therapy, for it suggests a multi-prong approach that targets strategies to decrease the rewarding properties of drugs, to enhance the rewarding properties of alternative reinforcers, to interfere with conditioned-learned associations, and to strengthen cognitive control in the treatment of drug addiction.
The medial prefrontal cortex (mPFC) plays a critical role in cocaine addiction. However, evidence to elucidate how the mPFC is functionally involved in cocaine addiction remains incomplete. Recent studies have revealed that repeated cocaine administration induces various neuroadaptations in pyramidal mPFC neurons, including a reduction in voltage-gated K+ currents (VGKCs) and a possible increase in voltage-sensitive Ca2+ currents (I(Ca)). Here, we performed both current-clamp recordings in brain slices and voltage-clamp recordings in freshly dissociated cells to determine whether I(Ca) is altered in mPFC pyramidal neurons after chronic cocaine treatment with a short-term or long-term withdrawal. In addition, a critical role of VGKCs in regulating the generation of Ca2+ plateau potential was also studied in mPFC neurons. Repeated cocaine administration significantly prolonged the duration of evoked Ca2+ plateau potentials and increased the whole-cell I(Ca) in mPFC neurons after a 3 d withdrawal. Selective blockade of L-type Ca2+ channels by nifedipine not only significantly increased the threshold but also reduced the duration and amplitude of Ca2+ plateau potentials in both saline- and cocaine-withdrawn mPFC neurons. However, there was no significant difference in the increased threshold, reduced duration, and decreased amplitude of Ca2+ potentials between saline- and cocaine-withdrawn neurons after blockade of L-type Ca2+ channels. Moreover, an increase in amplitude was also observed, whereas the prolonged duration persisted, in Ca2+ potentials after 2-3 weeks of withdrawal. These findings indicate that chronic exposure to cocaine facilitates the responsiveness of I(Ca), particularly via the activated L-type Ca2+ channels, to excitatory stimuli in rat mPFC pyramidal neurons.
Cocaine abuse increases the risk of life-threatening neurological complications such as strokes and seizures. Although the vasoconstricting properties of cocaine underlie its cerebrovascular effects, the mechanisms underlying its neurotoxicity remain incompletely understood. Here, we use optical techniques to measure cerebral blood volume, hemoglobin oxygenation (S(t)O(2)), and intracellular calcium ([Ca(2+)](i)) to test the hypothesis that cocaine increases [Ca(2+)](i) in the brain. The effects of cocaine were compared with those of methylphenidate, which has similar catecholaminergic effects as cocaine (except for serotonin increases) but no local anesthetic properties, and of lidocaine, which has similar local anesthetic effects as cocaine but is devoid of catecholaminergic actions. To control for the hemodynamic effects of cocaine, we assessed the effects of cocaine in animals in which normal blood pressure was maintained by infusion of phenylephrine, and we also measured the effects of transient hypotension (mimicking that induced by cocaine). We show that cocaine induced significant increases ( approximately 10-15%) in [Ca(2+)](i) that were independent of its hemodynamic effects and of the anesthetic used (isofluorance or alpha-chloralose). Lidocaine but not methylphenidate also induced significant [Ca(2+)](i) increases ( approximately 10-13%). This indicates that cocaine at a dose within the range used by drug users significantly increases the [Ca(2+)](i) in the brain and its local anesthetic, but neither its catecholaminergic nor its hemodynamic actions, underlies this effect. Cocaine-induced [Ca(2+)](i) increases are likely to accentuate the neurotoxic effects from cocaine-induced vasoconstriction and to facilitate the occurrence of seizures from the catecholaminergic effects of cocaine. These findings support the use of calcium channel blockers as a strategy to minimize the neurotoxic effects of cocaine.
Drug misuse and abuse are major health problems. Harmful drugs are regulated according to classification systems that purport to relate to the harms and risks of each drug. However, the methodology and processes underlying classification systems are generally neither specified nor transparent, which reduces confidence in their accuracy and undermines health education messages. We developed and explored the feasibility of the use of a nine-category matrix of harm, with an expert delphic procedure, to assess the harms of a range of illicit drugs in an evidence-based fashion. We also included five legal drugs of misuse (alcohol, khat, solvents, alkyl nitrites, and tobacco) and one that has since been classified (ketamine) for reference. The process proved practicable, and yielded roughly similar scores and rankings of drug harm when used by two separate groups of experts. The ranking of drugs produced by our assessment of harm differed from those used by current regulatory systems. Our methodology offers a systematic framework and process that could be used by national and international regulatory bodies to assess the harm of current and future drugs of abuse.
The drugs of abuse cocaine (C), heroin (H), and morphine (M) have been studied to enable understanding of the occurrence of cocaine–opioid interactions at a molecular level. Electrochemical, Raman, and NMR studies of the free drugs and their mixtures were used to study drug–drug interactions. The results were analyzed using data obtained from quantum-mechanical calculations. For the cocaine–morphine mixture (C–MH), formation of a binary complex was detected; this involved the 3-phenolic group and the heterocyclic oxygen of morphine and the carbonyl oxygen and the methyl protons of cocaine’s methyl ester group. NMR studies conducted simultaneously also revealed C–MH binding geometry consistent with theoretical predictions and with electrochemical and vibrational spectroscopy results. These results provide evidence for the occurrence of a cocaine–morphine interaction, both in the solid state and in solution, particularly for the hydrochloride form. A slight interaction, in solution, was also detected by NMR for the cocaine–heroin mixture.
Figure
"Schematic representation of the proposed model for cocaine:morphine salt interaction"
The oxidative behavior of heroin in aqueous solution is reported. In order to identify its oxidation peaks, several metabolites, 6-monoacetylmorphine, 3-monoacetylmorphine and norheroin, were synthesized and their electrochemical behavior studied using differential pulse voltammetry. The anodic waves observed for heroin correspond to the oxidation of the tertiary amine group and its follow-up product (secondary amine), and to the oxidation of the phenolic group obtained from hydrolysis, at alkaline pHs, of the 3-acetyl group. The results enabled a new oxidative mechanism for heroin to be proposed in which a secondary amine, norheroin, and an aldehyde are obtained. The voltammetric behavior of 6-monoacetylmorphine and morphine was found to be similar demonstrating that the presence of an acetyl substituent on the 6-hydroxy group does not have a relevant influence on the peak potential of the wave resulting from oxidation of the 3-phenolic group.
The efficacy of heroin metabolites for the stimulation of μ opioid receptor-mediated G-protein activation was investigated using agonist-stimulated [35S]guanosine-5′-O-(γ-thio)-triphosphate binding. In rat thalamic membranes, heroin and its primary metabolite, 6-monoacetylmorphine (6-MAM), were more efficacious than morphine or morphine-6-βd-glucuronide. This increased efficacy was not due to increased action of heroin and 6-MAM at δ receptors, as determined by competitive antagonism by naloxone, lack of antagonism by naltrindole, and competitive partial antagonism with morphine. In agreement with this interpretation, the same relative efficacy profile of heroin and its metabolites was observed at the cloned human μ opioid receptor expressed in C6 glioma cells. Moreover, these efficacy differences were GDP-dependent in a manner consistent with accepted mechanisms of receptor-mediated G-protein activation. The activity of heroin was attributed to in vitro deacetylation to 6-MAM, as confirmed by HPLC analysis. These results indicate that the heroin metabolite 6-MAM possesses higher efficacy than other heroin metabolites at μ opioid receptors, which may contribute to the higher efficacy of heroin compared with morphine in certain behavioral paradigms in vivo.
The efficacy of heroin metabolites for the stimulation of μ opioid receptor-mediated G-protein activation was investigated using agonist-stimulated [35S]guanosine-5′-O-(γ-thio)-triphosphate binding. In rat thalamic membranes, heroin and its primary metabolite, 6-monoacetylmorphine (6-MAM), were more efficacious than morphine or morphine-6-βd-glucuronide. This increased efficacy was not due to increased action of heroin and 6-MAM at δ receptors, as determined by competitive antagonism by naloxone, lack of antagonism by naltrindole, and competitive partial antagonism with morphine. In agreement with this interpretation, the same relative efficacy profile of heroin and its metabolites was observed at the cloned human μ opioid receptor expressed in C6 glioma cells. Moreover, these efficacy differences were GDP-dependent in a manner consistent with accepted mechanisms of receptor-mediated G-protein activation. The activity of heroin was attributed to in vitro deacetylation to 6-MAM, as confirmed by HPLC analysis. These results indicate that the heroin metabolite 6-MAM possesses higher efficacy than other heroin metabolites at μ opioid receptors, which may contribute to the higher efficacy of heroin compared with morphine in certain behavioral paradigms in vivo.
Since cocaine in blood rapidly hydrolyzes to benzoylecgonine, cocaine concentrations determined in postmortem blood may not reflect the presence or concentration of cocaine in the body at the time of death. The interpretative value of the determination of cocaine and benzoylecgonine in brain tissue was investigated. Cocaine and benzoylecgonine were quantitated by coextraction and formation of the propyl derivative of benzoylecgonine followed by selected ion monitoring gas chromatography/mass spectrometry (GC/MS) using electron ion impact ionization. Cocaine and benzoylecgonine were found to be evenly distributed throughout the brain. Cocaine and benzoylecgonine concentrations were stable in frozen brain tissue (-4 degrees C) on reanalysis after 1 to 3 months of storage, and in refrigerated tissue (10 degrees C) after 30 days of storage. Blood, brain, and liver concentrations of cocaine and benzoylecgonine in 37 cocaine overdose cases and 46 cases in which cocaine was incidental to the cause of death were reviewed. The ratios of cocaine/benzoylecgonine in the toxic cases (brain mean 14.7 and blood mean 0.64) were clearly different from those found in the incidental cases (brain mean 0.87 and blood mean 0.27). The brain/blood ratios of cocaine and benzoylecgonine concentrations generally were characteristic of the time elapsed since cocaine dosing. In cocaine overdose cases, the mean ratio was 9.6 for cocaine and 0.36 for benzoylecgonine. These are within the range found in animal studies for brain/blood ratios of cocaine and benzoylecgonine 0.5 to 2 h after cocaine administration. In incidental cases, the brain/blood ratios were mean 2.5 for cocaine and 1.4 for benzoylecgonine.(ABSTRACT TRUNCATED AT 250 WORDS)
The relative affinity to opiate receptors of heroin, 6-acetylmorphine and morphine was estimated by determining their ability to displace specifically bound 3H-naltrexone from rat brain opiate binding sites. In vitro hydrolysis of heroin to 6-acetylmorphine was monitored in the binding assay filtrate by use of a quantitative HPLC procedure. The rate of heroin hydrolysis was significantly slower at 0 degrees C than at 37 degrees C. The displacement of 1 nM 3H-naltrexone by unlabeled ligand at concentrations ranging from 7 to 500 nM was measured at 0 degrees C for 120 minutes, yielding IC50 values of heroin = 483 nM, 6-acetylmorphine = 73 nM and morphine = 53 nM. When the binding data for heroin were recalculated to include the displacement that could be attributed to the 6-acetylmorphine derived from heroin degradation during the incubation, all of the apparent heroin binding was accounted for by the 6-acetylmorphine. These results are consistent with previous reports of the low binding affinity of morphine congeners (e.g., codeine) that lack a free phenolic 3-hydroxyl group and support the view that heroin is a prodrug which serves to determine the distribution of its intrinsically active metabolites, 6-acetylmorphine and morphine.
Morphological alterations of cardiac mitochondria have been observed in rats chronically treated with cocaine. Whether cocaine directly causes heart mitochondrial dysfunction remains unclear. The present study was undertaken to investigate the effect of cocaine on mitochondrial function in cultured myocardial cells. Cells were incubated with cocaine (10(-5)-10(-3) M) for 3-72 h, using either a repeated or single exposure protocol. Cocaine (10(-3) M) produced severe cytotoxicity after repeated exposure (24-72 h), as elevated by leakage of lactate dehydrogenase. Treatment of the cultures with a single exposure protocol (10(-5)-10(-3) M for 24 h or less) produced a very modest cytotoxic effect, as shown by a small increase in LDH leakage. However, cellular ATP levels showed a time-dependent decline in cultures treated with the single exposure protocol. Experiments using a digitized fluorescence imaging system revealed that cocaine (single exposure protocol) caused a dose- and time-dependent decrease in mitochondrial membrane potential, and the decline in membrane potential occurred prior to manifestation of cytotoxicity shown with the repeated exposure protocol. Cytosolic and mitochondrial calcium levels, as determined by fura-2, were not affected during treatment with cocaine. Our results suggest that cocaine may compromise cardiac mitochondrial function and may lead to cardiotoxicity.
Cocaine use poses a major health problem not only because of the dependence it causes but also because of the generation of life-threatening cardiac arrhythmias following overdose. Elucidating the molecular mechanisms of action of cocaine, therefore, remains a critical step in developing treatment for cocaine addiction and preventing cardiac complications. Although the neurotransmitter transporters are suggested to be primary targets for cocaine, the continued drug-seeking behavior of transporter knock-out mice suggests the involvement of additional mechanisms. Several studies have shown that voltage-gated calcium channel blockers can prevent the behavioral and reinforcing effects of the drug and also cocaine-induced cardiac events, including lethal ventricular fibrillation. However, the role of voltage-gated calcium channels in cocaine-induced responses is not clear. Herein, I show that cocaine, in pharmacological doses, selectively and potently enhances L-type calcium channel currents in isolated rat ventricular myocytes. This potentiation by cocaine is due to an increase and decrease, respectively, in the calcium channel opening and closing rates, with no apparent effects on voltage-dependence or single-channel conductance. The effects of cocaine are rapidly reversible and unaffected by prior ATPgammaS-induced channel phosphorylation. These results suggest that cocaine directly binds and facilitates the opening of L-type calcium channels. Importantly, elevated intracellular calcium levels via this mechanism triggering second messenger pathways and gene activation may contribute to many of the cardiovascular and central nervous system effects of cocaine.
Cardiotoxicity is commonly associated with cocaine abuse. Previous studies have indicated that cocaine alters myocardial mitochondrial function. This study was undertaken to investigate the effect of cocaine on activity of the mitochondrial electron transport chain in cultures of neonatal rat cardiomyocytes and in isolated myocardial mitochondria. Cocaine concentrations (10(-5) to 10(-3) M) were used, and these concentrations have been reported in human cocaine users and are within a similar range of cocaine concentrations used in studies in vivo. After 24 hr treatment of cocaine, there was a slight increase in lactate dehydrogenase leakage in the cells treated with cocaine (10(-3) M). Reduction of tetrazolium compounds, neotetrazolium chloride (NTC) and triphenyltetrazolium chloride (TTC) was analyzed in intact cells to assess activity of the mitochondrial electron transport chain. Cocaine (10(-3) M) did not significantly change TTC and NTC reduction. In isolated mitochondria, cocaine (10(-3) M) significantly inhibited glutamate/malate-mediated respiration. These data suggest that cocaine at high concentrations may inhibit complex I of the mitochondrial electron transport chain of myocardial cells.
The binding, internalization, and trafficking of the fluorescently labeled opioid peptides Fluo-dermorphin and Fluo-deltorphin were quantitatively studied by confocal microscopy in primary cortical neurons in culture. Specific binding of these selective ligands to neurons naturally expressing mu (mu) and delta (delta) opioid receptors (OR), respectively, resulted in their internalization into neuronal somas and processes, as indicated by the persistence of fluorescent labeling following removal of cell surface binding by hypertonic acid wash. This internalization was receptor-specific, as the fluorescent signal was completely abolished when the cells were concomitantly incubated with the opioid receptor antagonist naloxone. It also was clathrin-dependent, as it was totally prevented by the endocytosis inhibitor phenylarsine oxide. Accordingly, internalized ligands were detected inside small, endosome-like vesicles. These labeled vesicles accumulated within nerve cell bodies between 5-30 min of incubation with the fluorescent ligands. This accumulation was abolished after treatment with the antitubular agent nocodazole, suggesting that it was due to a microtubule-dependent, retrograde transport of the internalized ligands from processes to the soma. By contrast, there was no change in the compartmentalization of internalized (mu)OR or deltaOR, as assessed by immunocytochemistry, suggesting that the latter were recycled locally. The present results provide the first demonstration of receptor-mediated internalization of opioid peptides in cultured neurons. It is proposed that their retrograde transport into target cells might be involved in mediating some of the long-term, transcriptional effects of opioids.
Cell death and reactive oxygen species production have been suggested to be involved in neurodegeneration induced by the drugs of abuse. In this study we analyze the toxicity of the following drugs of abuse: heroin, morphine, d-amphetamine, and cocaine in undifferentiated PC12 cells, used as dopaminergic neuronal models. Our data show that opioid drugs (heroin and morphine) are more toxic than stimulant drugs (d-amphetamine and cocaine). Toxic effects induced by heroin are associated with a decrease in intracellular dopamine, an increase in DOPAC levels, and the formation of ROS, whereas toxic effects induced by amphetamine are associated with a decrease in intracellular dopamine and in ATP/ADP levels. In contrast with cocaine, both amphetamine and heroin induced features of apoptosis. The data suggest that the death of cultured PC12 cells induced by the drugs of abuse is correlated with a decrease in intracellular dopamine levels, which can be associated with an increased dopamine turnover and oxidative cell injury.
The use of cocaine by heroin-dependent individuals, or by patients in methadone or buprenorphine maintenance treatment, is substantial and has negative consequences on health, social adjustment and outcome of opioid-addiction treatment. The pharmacological reasons for cocaine use in opioid-dependent individuals, however, are poorly understood and little is known about the patterns of heroin and cocaine co-use. We reviewed anecdotal evidence suggesting that cocaine is co-used with opioid drugs in a variety of different patterns, to achieve different goals. Clinical and preclinical experimental evidence indicates that the simultaneous administration of cocaine and heroin (i.e. 'speedball') does not induce a novel set of subjective effects, nor is it more reinforcing than either drug alone, especially when the doses of heroin and cocaine are high. There is mixed evidence that the subjective effects of cocaine are enhanced in individuals dependent on opioids, although it is clear that cocaine can alleviate the severity of symptoms of withdrawal from opioids. We also reviewed preclinical studies investigating possible neurobiological interactions between opioids and cocaine, but the results of these studies have been difficult to interpret mainly because the neurochemical mechanisms mediating the motivational effects of cocaine are modified by dependence on, and withdrawal from, opioid drugs. Our analysis encourages further systematic investigation of cocaine use patterns among opioid-dependent individuals and in laboratory animals. Once clearly identified, pharmacological and neuroanatomical methods can be employed in self-administering laboratory animals to uncover the neurobiological correlates of specific patterns of co-use.
To live or to die? This crucial question eloquently reflects the dual role of Ca2+ in living organisms--survival factor or ruthless killer. It has long been known that Ca2+ signals govern a host of vital cell functions and so are necessary for cell survival. However, more recently it has become clear that cellular Ca2+ overload, or perturbation of intracellular Ca2+ compartmentalization, can cause cytotoxicity and trigger either apoptotic or necrotic cell death.
To determine the cardiovascular molecular events associated with acute exposure to cocaine, the present study utilized in vivo analysis of left-ventricular heart function in adult rabbits, fluorescence confocal microscopy of fluo-2, rhod-2, (5-(and-6) carboxy 2',7' dichlorodihydrofluores-cein diacetate (carboxy-H2DCFDA), and JC-1 in H9C2 cells and gene expression microarray technology for analysis of gene activation in both rabbit ventricular tissue and H9C2 cells. In the rabbit, acute cocaine exposure (2 mg/kg) caused left-ventricular dysfunction and 0.1-10 mM cocaine increased cytosolic and mitochondrial calcium activity and mitochondrial membrane depolarization in H9C2 cells. A 3-min pretreatment of H9C2 cells by 10 microM verapamil, nifedipine, or nadolol inhibited calcium increases, but only 1 mM N-acetylcysteine (NAC) or 1 mM glutathione blocked mitochondrial membrane depolarization. Cocaine induced activation of genes in the rabbit heart and H9C2 cells including angiotensinogen, ADRB1, and c-reactive protein (CRP). In H9C2 cells, NAC pretreatment blocked cocaine-mediated increases in CRP, FAS, FAS ligand, and cytokine receptor-like factor1 (CRLF1) expression. Collectively, these data suggest that acute cocaine administration initiates cellular and genetic changes that, if chronically manifested, could cause cardiac deficits similar to those seen in heart failure and ischemia, such as ventricular dysfunction, cardiac arrhythmias, and cardiac remodeling.
Drug abuse is associated with brain dysfunction and neurodegeneration, and various recreational drugs induce apoptotic cell death. This study examined the role of the mitochondrial apoptotic pathway in psychostimulant-induced neuronal dysfunction. Using primary neuronal cultures, we observed that amphetamine (IC50=1.40 mM) was more potent than cocaine (IC50=4.30 mM) in inducing cell toxicity. Apoptotic cell death was further evaluated using cocaine and amphetamine concentrations that moderately decreased cell reduction capacity but did not affect plasma membrane integrity. Compared to cocaine, amphetamine highly decreased the mitochondrial membrane potential, as determined using the fluorescent probe rhodamine-123, whereas both drugs decreased mitochondrial cytochrome c. In contrast to amphetamine, cocaine cytotoxicity was partly mediated through effects on the electron transport chain, since cocaine toxicity was ameliorated in mitochondrial DNA-depleted cells lacking mitochondrially encoded electron transport chain subunits. Cocaine and amphetamine induced activation of caspases-2, -3 and -9 but did not affect activity of caspases-6 or -8. In addition, amphetamine, but not cocaine, was associated with the appearance of evident nuclear apoptotic morphology. These events were not accompanied by differences in the release of the apoptosis-inducing factor (AIF) from mitochondria. Our results demonstrate that although both amphetamine and cocaine activate the mitochondrial apoptotic pathway in cortical neurons, amphetamine is more likely to promote apoptosis.
Recent data have revealed an unexpected role of Bcl-2 in modulating the steady-state levels and agonist-dependent fluxes of Ca(2+) ions. Direct monitoring of endoplasmic reticulum (ER) Ca(2+) concentration with recombinant probes reveals a lower state of filling in Bcl-2-overexpressing cells and a higher leak rate from the organelle. The broader set of indirect data using cytosolic probes reveals a more complex scenario, as in many cases no difference was detected in the Ca(2+) content of the intracellular pools. At the same time, Ca(2+) signals have been shown to affect important checkpoints of the apoptotic process, such as mitochondria, thus tuning the sensitivity of cells to various challenges. In this contribution, we will review (i) the data on the effect of Bcl-2 on [Ca(2+)](er), (ii) the functional significance of the Ca(2+)-signalling alteration and (iii) the current insight into the possible mechanisms of this effect.
The aim of this study was to evaluate postmortem incorporation of opiates in bone and bone marrow after diacetylmorphine (heroin) administration to mice. Mice were given acute (lethal dose of 300 mg/kg) or chronic (10 and 20 mg/kg/24 h for 20 days) intraperitoneal administration of diacetylmorphine. The two metabolites of diacetylmorphine, 6-acetylmorphine (6-AM) and morphine, were extracted from whole blood, brain, spinal cord, bone marrow and bone (after hydrolysis) using a liquid/liquid method. Quantification was performed by gas chromatography-mass spectrometry (GC/MS). Results showed that after acute administration, opiates were present in all studied tissues. Morphine concentrations appeared to be higher than those of 6-AM in blood (52.4 microg/mL versus 27.7 microg/mL, n=12), bone marrow (87.8 ng/mg versus 8.9 ng/mg, n=6) and bone (0.85 ng/mg versus 0.43 ng/mg, n=6), but 6-AM concentrations were higher than those of morphine in brain (14.0 ng/mg versus 7.4 ng/mg, n=12) and spinal cord (27.8 ng/mg versus 20.8 ng/mg, n=12). No correlation was found for both compounds between blood concentrations and either brain, spinal cord, bone or bone marrow concentrations while a significant one was found between brain and spinal cord concentrations either for morphine (r=0.89, n=12, p<0.001) or 6-AM (r=0.93, n=12, p<0.001), the concentration being higher in spinal cord than in brain. When bones were stored for 2 months, only 6-AM remained in bone marrow but not in bone. After chronic administration, mice being sacrificed by cervical dislocation 24 h after the last injection, no opiate was detected in any studied tissues. Further studies are required, in particular in human bones, but these results seem to show that 6-AM could be detect in bone marrow several weeks after the death and could be an alternative tissue for forensic toxicologist to detect a fatal diacetylmorphine overdose, even if no correlation between blood and bone marrow was observed. On the other hand, neither bone tissue nor bone marrow will allow the confirmation of a chronic diacetylmorphine use.
In heroin overdose deaths the blood morphine concentration varies substantially. To explore possible pharmacokinetic explanations for variable sensitivity to opiate toxicity we studied mortality and drug concentrations in male Sprague-Dawley rats. Groups of rats were injected intravenously (i.v.) with heroin, 21.5 mg/kg, or morphine, 223 mg/kg, causing a 60-80% mortality among drug-naïve rats. Additional groups of rats were pre-treated with morphine for 14 days, with or without 1 week of subsequent abstinence. Brain, lung and blood samples were analyzed for 6-acetylmorphine, morphine, morphine-3-glucuronide and morphine-6-glucuronide. i.v. morphine administration to drug-naïve rats resulted in both rapid and delayed deaths. The brain morphine concentration conformed to an exponential elimination curve in all samples, ruling out accumulation of morphine as an explanation for delayed deaths. This study found no support for formation of toxic concentration of morphine-6-glucuronide. Spontaneous death among both heroin and morphine rats occurred at fairly uniform brain morphine concentrations. Morphine pre-treatment significantly reduced mortality upon i.v. morphine injection, but the protective effect was less evident upon i.v. heroin challenge. The morphine pre-treatment still afforded some protection after 1 week of abstinence among rats receiving i.v. morphine, whereas rats given i.v. heroin showed similar death rate as drug-naïve rats.
Cocaine inhibits survival and growth of rat locus coeruleus (LC) neurons, which may mediate alterations in attention, following in utero exposure to cocaine. These effects are most severe in early gestation during peak neuritogenesis. Prenatal cocaine exposure may specifically decrease LC survival through an apoptotic pathway involving caspases. Dissociated fetal LC neurons or substantia nigra (SN) neurons (control) were exposed in vitro to a pharmacologically active dose of cocaine hydrochloride (500 ng/ml) and assayed for apoptosis using terminal deoxynucleotidyl transferase mediated DNA nick end labeling and Hoechst methodologies. Cocaine exposure decreased survival and induced apoptosis in LC neurons, with no changes in survival of SN neurons. Activation of apoptotic signal transduction proteins was determined using enzyme assays and immunoblotting at 30 min, 1 h, 4 h and 24 h. In LC neurons, Bax levels were induced at 30 min and 1 h, following cocaine treatment, and Bcl-2 levels remained unchanged at all time points, altering the Bax/Bcl-2 ratio. The ratio was reversed for SN neurons (elevated Bcl-2 levels and transient reduction of Bax levels). Further, cocaine exposure significantly increased caspase-9 and caspase-3 activities at all time points, without changes in caspase-8 activity in LC neurons. In addition, cleavage of caspase-3 target proteins, alpha-fodrin and poly (ADP-ribose) polymerase (PARP) were observed following cocaine treatment. In contrast, SN neurons showed either significant reductions, or no significant changes, in caspase-3, -8 or -9 activities or caspase-3 target proteins, alpha-fodrin and PARP. Thus, cocaine exposure in vitro may preferentially induce apoptosis in fetal LC neurons putatively regulated by Bax, via activation of caspases and their downstream target proteins.
The concomitant use of cocaine by heroin-dependent subjects, or by patients on methadone maintenance treatment, is a relevant phenomenon that determines the negative consequences on health, social adjustment, and outcome of opioid addiction treatment. Little is known about the patterns of co-use of these two substances and the pathophysiological alterations following this condition. Only a few studies have evaluated the neurochemical effects in subjects carrying this specific pattern of abuse. Similarly, the impact of cocaine abuse on psychiatric and social function in subjects already affected by opioid addiction is still poorly understood and further studies are necessary to investigate this specific area that could profoundly affect methadone maintenance treatment. The aim of this article is to investigate the psychopathological symptoms of heroin-cocaine abuse in a group of heroin addicts applying for treatment. Results show a direct relationship between cocaine abuse and a higher rate of psychiatric disorders, but a negative correlation with the severity of self-rated psychopathology.
Cortical function has been suggested to be highly compromised by repeated heroin self-administration. We have previously shown that street heroin induces apoptosis in neuronal-like PC12 cells. Thus, we analysed the apoptotic pathways involved in street heroin neurotoxicity using primary cultures of rat cortical neurons. Our street heroin sample was shown to be mainly composed by heroin, 6-monoacetylmorphine and morphine. Exposure of cortical neurons to street heroin induced a slight decrease in metabolic viability, without loss of neuronal integrity. Early activation of caspases involved in the mitochondrial apoptotic pathway was observed, culminating in caspase 3 activation, Poly-ADP Ribose Polymerase (PARP) cleavage and DNA fragmentation. Apoptotic morphology was completely prevented by the non-selective caspase inhibitor z-VAD-fmk, indicating an important role for caspases in neurodegeneration induced by street heroin. Ionotropic glutamate receptors, opioid receptors and oxidative stress were not involved in caspase 3 activation. Interestingly, street heroin cytotoxicity was shown to be independent of a functional mitochondrial respiratory chain, as determined using NT-2 rho(0) cells. Nonetheless, in street heroin-treated cortical neurons, cytochrome c was released, accompanied by a decrease in mitochondrial potential and Bcl-2/Bax. Pure heroin hydrochloride similarly decreased metabolic viability but only slightly activated caspase 3. Altogether, our data suggest an important role for mitochondria in mediating street heroin neurotoxic effects.
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- Jr Atkinson
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Cocaine induces cell death and activates the transcription nuclear factor kappa-b in pc12 cells Understanding polydrug use: review of heroin and cocaine co-use
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The addicted human brain: insights from imaging studies
- N D Volkow
- J S Fowler
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Polydrug use: patterns and responses
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- S Orrenius
- B Zhivotovsky
- P Nicotera
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Regulation of cell death: the calcium-apoptosis link
- Orrenius