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Neuroprotective effect of cannabidiol, a non‐psychoactive component from Cannabis sativa, on β‐amyloid‐induced toxicity in PC12 cells
Abstract
Abstract Alzheimer's disease is widely held to be associated with oxidative stress due, in part, to the membrane action of beta-amyloid peptide aggregates. Here, we studied the effect of cannabidiol, a major non-psychoactive component of the marijuana plant (Cannabis sativa) on beta-amyloid peptide-induced toxicity in cultured rat pheocromocytoma PC12 cells. Following exposure of cells to beta-amyloid peptide (1 micro g/mL), a marked reduction in cell survival was observed. This effect was associated with increased reactive oxygen species (ROS) production and lipid peroxidation, as well as caspase 3 (a key enzyme in the apoptosis cell-signalling cascade) appearance, DNA fragmentation and increased intracellular calcium. Treatment of the cells with cannabidiol (10(-7)-10(-4)m) prior to beta-amyloid peptide exposure significantly elevated cell survival while it decreased ROS production, lipid peroxidation, caspase 3 levels, DNA fragmentation and intracellular calcium. Our results indicate that cannabidiol exerts a combination of neuroprotective, anti-oxidative and anti-apoptotic effects against beta-amyloid peptide toxicity, and that inhibition of caspase 3 appearance from its inactive precursor, pro-caspase 3, by cannabidiol is involved in the signalling pathway for this neuroprotection.
... Although evidence has shown a slight effect of CBD on Aβ and tau pathology in vitro, CBD-mediated improvement in cognitive behavior is associated with the neuroprotective role of CBD against Aβ-induced cytotoxicity. It has been reported that in PC12 cells, CBD decreases Aβ-stimulated ROS and NO production, along with p38 MAPK and NF-κB, which is a redox-sensitive transcription factor that is activated under oxidative and inflammatory conditions [100,101]. Moreover, an increased expression of p50 and Previous studies have observed a promising effect of CBD on improving cognitive impairment in AD mice. ...
... Although evidence has shown a slight effect of CBD on Aβ and tau pathology in vitro, CBD-mediated improvement in cognitive behavior is associated with the neuroprotective role of CBD against Aβ-induced cytotoxicity. It has been reported that in PC12 cells, CBD decreases Aβ-stimulated ROS and NO production, along with p38 MAPK and NF-κB, which is a redox-sensitive transcription factor that is activated under oxidative and inflammatory conditions [100,101]. Moreover, an increased expression of p50 and p65, the components of NF-κB, parallel to upregulated GFAP, S100, iNOS, and inflammatory factors was observed in Aβ-treated cultured astrocytes [102]. ...
... CBD can blunt Aβ-induced oxidative stress and neuroinflammation in astrocytes through PPARγ [102]. Meanwhile, Aβ-induced neuroinflammation and oxidative stress were associated with increased cell death and CBD treatment before Aβ treatment or to APP-transfected neuroblastoma cells improved cell survival [96,100]. In addition, CBD-treated SH-SY5Y APP+ cells showed a smaller number of apoptotic cells. ...
Alzheimer’s disease (AD), the most common neurodegenerative disease, is characterized by progressive cognitive impairment. The deposition of amyloid beta (Aβ) and hyperphosphorylated tau is considered the hallmark of AD pathology. Many therapeutic approaches such as Food and Drug Administration-approved cholinesterase inhibitors and N–methyl–D–aspartate receptor antagonists have been used to intervene in AD pathology. However, current therapies only provide limited symptomatic relief and are ineffective in preventing AD progression. Cannabidiol (CBD), a phytocannabinoid devoid of psychoactive responses, provides neuroprotective effects through both cannabinoid and noncannabinoid receptors. Recent studies using an AD mouse model have suggested that CBD can reverse cognitive deficits along with Aβ-induced neuroinflammatory, oxidative responses, and neuronal death. Furthermore, CBD can reduce the accumulation of Aβ and hyperphosphorylation of tau, suggesting the possibility of delaying AD progression. Particularly, the noncannabinoid receptor, peroxisome proliferator-activated receptor gamma, has been suggested to be involved in multiple functions of CBD. Therefore, understanding the underlying mechanisms of CBD is necessary for intervening in AD pathology in depth and for the translation of preclinical studies into clinical settings. In this review, we summarize recent studies on the effect of CBD in AD and suggest problems to be overcome for the therapeutic use of CBD.
... In this contest, the anti-inflammatory properties of CBD were evaluated by both in vitro and in vivo studies in an animal model of Ab-induced neuroinflammation (Iuvone et al., 2004;Esposito et al., 2006;Esposito et al., 2007;Esposito et al., 2011). In particular, authors demonstrated that CBD reduces the tau protein hyperphosphorylation through the inhibition of Wingless-type MMTV integration site family member (Wnt) pathways and significantly attenuates all the markers of the Abinduced neuroinflammation, including the glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS) protein expression, nitrite production, and interleukin 1 b (IL-1b) (Iuvone et al., 2004;Esposito et al., 2006;Esposito et al., 2007;Iuvone et al., 2009;Esposito et al., 2011). ...
... In this contest, the anti-inflammatory properties of CBD were evaluated by both in vitro and in vivo studies in an animal model of Ab-induced neuroinflammation (Iuvone et al., 2004;Esposito et al., 2006;Esposito et al., 2007;Esposito et al., 2011). In particular, authors demonstrated that CBD reduces the tau protein hyperphosphorylation through the inhibition of Wingless-type MMTV integration site family member (Wnt) pathways and significantly attenuates all the markers of the Abinduced neuroinflammation, including the glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS) protein expression, nitrite production, and interleukin 1 b (IL-1b) (Iuvone et al., 2004;Esposito et al., 2006;Esposito et al., 2007;Iuvone et al., 2009;Esposito et al., 2011). CBD pre-treatment induces a reduction of ROS production, lipid peroxidation, caspase-3 levels, and DNA fragmentation in PC12 cells stimulated by Ab, an in vitro model of AD (Iuvone et al., 2004;Bedse et al., 2014;Gallelli et al., 2018). ...
... In particular, authors demonstrated that CBD reduces the tau protein hyperphosphorylation through the inhibition of Wingless-type MMTV integration site family member (Wnt) pathways and significantly attenuates all the markers of the Abinduced neuroinflammation, including the glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS) protein expression, nitrite production, and interleukin 1 b (IL-1b) (Iuvone et al., 2004;Esposito et al., 2006;Esposito et al., 2007;Iuvone et al., 2009;Esposito et al., 2011). CBD pre-treatment induces a reduction of ROS production, lipid peroxidation, caspase-3 levels, and DNA fragmentation in PC12 cells stimulated by Ab, an in vitro model of AD (Iuvone et al., 2004;Bedse et al., 2014;Gallelli et al., 2018). ...
Cannabis sativa, commonly known as marijuana, contains a pool of secondary plant metabolites with therapeutic effects. Besides Δ9-tetrahydrocannabinol that is the principal psychoactive constituent of Cannabis, cannabidiol (CBD) is the most abundant nonpsychoactive phytocannabinoid and may represent a prototype for anti-inflammatory drug development for human pathologies where both the inflammation and oxidative stress (OS) play an important role to their etiology and progression. To this regard, Alzheimer's disease (AD), Parkinson's disease (PD), the most common neurodegenerative disorders, are characterized by extensive oxidative damage to different biological substrates that can cause cell death by different pathways. Most cases of neurodegenerative diseases have a complex etiology with a variety of factors contributing to the progression of the neurodegenerative processes; therefore, promising treatment strategies should simultaneously target multiple substrates in order to stop and/or slow down the neurodegeneration. In this context, CBD, which interacts with the eCB system, but has also cannabinoid receptor-independent mechanism, might be a good candidate as a prototype for anti-oxidant drug development for the major neurodegenerative disorders, such as PD and AD. This review summarizes the multiple molecular pathways that underlie the positive effects of CBD, which may have a considerable impact on the progression of the major neurodegenerative disorders.
... In this context, the strong antioxidant effect of CBD was reported against glutamate toxicity in primary neuronal culture [68]. The neuroprotection and antioxidant properties of CBD were also observed on β-amyloid peptide-induced toxicity in cultured rat PC12 cells [84]. CBD modulates microglial cell function in vitro and prevents the learning of a spatial navigation task and TNF-α and IL-6 gene expression in β-amyloid-injected mice [71,85]. ...
... No psycoactive effets [80] Neuroprotection [84] Reduce microglia activation [85] Delay cognitive decline [167] Hypotension at high doses [168] Anxiogenic-like effect [169] WIN 55,212-2 HU 210 CP 55,940 JWH-018 ...
Alzheimer’s disease (AD) is a detrimental brain disorder characterized by a gradual cognitive decline and neuronal deterioration. To date, the treatments available are effective only in the early stage of the disease. The AD etiology has not been completely revealed, and investigating new pathological mechanisms is essential for developing effective and safe drugs. The recreational and pharmacological properties of marijuana are known for centuries, but only recently the scientific community started to investigate the potential use of cannabinoids in AD therapy—sometimes with contradictory outcomes. Since the endocannabinoid system (ECS) is highly expressed in the hippocampus and cortex, cannabis use/abuse has often been associated with memory and learning dysfunction in vulnerable individuals. However, the latest findings in AD rodent models have shown promising effects of cannabinoids in reducing amyloid plaque deposition and stimulating hippocampal neurogenesis. Beneficial effects on several dementia-related symptoms have also been reported in clinical trials after cannabinoid treatments. Accordingly, future studies should address identifying the correct therapeutic dosage and timing of treatment from the perspective of using cannabinoids in AD therapy. The present paper aims to summarize the potential and limitations of cannabinoids as therapeutics for AD, focusing on recent pre-clinical and clinical evidence.
... Generally, different Cannabis extracts present different proportions between CBD and THC, which may modify pharmacological and psychological effects (Potter et al., 2008). In that context, CBD has been shown to be a promising compound due to its hypnotic (Carlini and Cunha, 1981;Monti, 1977;Pickens, 1981), antiinflammatory (Costa et al., 2004;Esposito et al., 2011), antioxidants (Hampson et al., 1998(Hampson et al., , 2000, antipsychotic (Zuardi et al., 1991;2006) and neuroprotective (Hampson et al., 1998(Hampson et al., , 2000Iuvone et al., 2004) properties. Additionally, CBD presents low toxicity, high tolerability and the lack of psychoactive effects (Bergamaschi et al., 2011;Carlini and Cunha, 1981;Cunha et al., 1980), supporting its safe pharmacological use. ...
... In that context, identification of potential drugs that could induce neuroprotection, like CBD, certainly has an impact on epilepsies treatment, for this purpose preclinical studies are required. Neuroprotective CBD effects are observed in numerous neurodegenerative disorders in preclinical research, such as in Huntington, Parkinson, and Alzheimer diseases (Campos et al., 2016;Fernández-Ruiz et al., 2013;Iuvone et al., 2004). Nevertheless, few data were found associated with neuroprotection in preclinical studies of the epilepsies. ...
Epilepsy is a neurological disorder characterized by the presence of seizures and neuropsychiatric comorbidities. Despite the number of antiepileptic drugs, one-third of patients did not have their seizures under control, leading to pharmacoresistance epilepsy. Cannabis sativa has been used since ancient times in Medicine for the treatment of many diseases, including convulsive seizures. In this context, Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been a promising compound for treating epilepsies due to its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. In this review, we summarize evidence of the CBD anticonvulsant activities present in a great diversity of animal models. Special attention was given to behavioral CBD effects and its translation to human epilepsies. CBD anticonvulsant effects are associated with a great variety of mechanisms of action such as endocannabinoid and calcium signaling. CBD has shown effectiveness in the clinical scenario for epilepsies, but its effects on epilepsy-related comorbidities are scarce even in basic research. More detailed and complex behavioral evaluation about CBD effects on seizures and epilepsy-related comorbidities are required.
... In vitro studies have shown that CBD dosedependently inhibits tau hyperphosphorylation in Aβ-simulated PC12 cells (Esposito et al., 2006a). Furthermore, CBD can increase cell survival, reduce Aβ-induced lipid peroxidation and reactive oxygen species production (Iuvone et al., 2004), attenuate nitric oxide (Esposito et al., 2006b), and counteract the elevation of APP expression in transfected human neuroblastoma cells, thereby increasing cell survival (Scuderi et al., 2014). In vivo, CBD has been found to attenuate Aβ-evoked neuroinflammation in a pharmacological mouse model of AD (Esposito et al., 2007). ...
... In brief, in vitro studies have shown that CBD acts against Aβ-induced toxicity in various ways, including inhibition of tau hyperphosphorylation (Esposito et al., 2006a) which was associated with a reduction in the phosphorylated glycogen synthase kinase 3β, the protein responsible for NFT formation in AD. In addition, CBD can increase cell survival, reduce Aβ-induced lipid peroxidation, reactive oxygen species production (Iuvone et al., 2004), and attenuate nitric oxide production via inhibition of phosphorylated p38 mitogen-activated protein kinase and transcription factor nuclear factor-κB (Esposito et al., 2006b). Finally, CBD can counteract the elevation of APP expression by inducing ubiquitination of APP through activation of peroxisome proliferator-activated receptor-γ (PPARγ; Scuderi et al., 2014). ...
Alzheimer's disease (AD) is a neurodegenerative disease that causes behavioral and cognitive impairments. The phytocannabinoid cannabidiol (CBD) has anti-inflammatory, antioxidant, and neuroprotective properties, and in vitro and limited in vivo evidence suggests that CBD possesses therapeutic-like properties for the treatment of AD. Cannabinoids are known to have dose-dependent effects and the therapeutic potential of medium-dose CBD for AD transgenic mice has not been assessed in great detail yet. 12-month-old control and APP
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/PS1ΔE9 (APPxPS1) transgenic female mice were treated daily via intraperitoneal injection with 5 mg/kg bodyweight CBD (or vehicle) commencing three weeks prior to the assessment of behavioral domains including anxiety, exploration, locomotion, motor functions, cognition, and sensorimotor gating. APPxPS1 mice exhibited a hyperlocomotive and anxiogenic-like phenotype and had wild type-like motor and spatial learning abilities, although AD transgenic mice took generally longer to complete the cheeseboard training (due to a lower locomotion speed). Furthermore spatial learning and reversal learning was delayed by one day in APPxPS1 mice compared to control mice. All mice displayed intact spatial memory and retrieval memory, but APPxPS1 mice showed reduced levels of perseverance in the cheeseboard probe trial. Importantly, vehicle-treated APPxPS1 mice were characterized by object recognition deficits and delayed spatial learning, which were reversed by CBD treatment. Finally, impairments in sensorimotor gating of APPxPS1 mice were not affected by CBD. In conclusion, medium-dose CBD appears to have therapeutic value for the treatment of particular behavioral impairments present in AD patients. Future research should consider the molecular mechanisms behind CBD's beneficial properties for AD transgenic mice.
... Iuvone et al. demonstrated that CBD (10 μM) attenuated apoptosis in PC12 cells by reducing intracellular calcium accumulation, lipid peroxidation, ROS generation, and downregulating caspase-3 level. CBD also demonstrated an antioxidant effect by inhibiting inducible nitric oxide synthase protein expression and nitric oxide production, followed by blocking p38 MAP kinase phosphorylation and the NF-κB activation (Esposito et al., 2006a;Iuvone et al., 2004). In the H 2 O 2 induced OS model, CBD has shown to protect primary hippocampal neurons, oligodendrocyte progenitor cells, and cerebellar granule cells (Lupica et al., 2017;Mecha et al., 2012;Ricart and Fiszman, 2001). ...
... Iuvone et al. addressed that CBD was effective in reducing Aβmediated neurotoxicity, where they found that treatment of CBD in PC12 cells at a dose of 0.1 μM-100 μM decreased expressions of caspase-3, ROS and intracellular Ca 2+ level. Furthermore, CBD reduced lipid peroxidation, which eventually protects cells from apoptosis (Iuvone et al., 2004). In addition, Esposito et al. found that CBD at a dose of 1μM to 100 μM inhibits iNOS expression and p38 MAPK phosphorylation, and thus reduces intracellular NO level and NF-kB activation in the same cell line (Esposito et al., 2006b). ...
The aberrant accumulation of disease-specific protein aggregates accompanying cognitive decline is a pathological hallmark of age-associated neurological disorders, also termed as proteinopathies, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis and multiple sclerosis. Along with oxidative stress and neuroinflammation, disruption in protein homeostasis (proteostasis), a network that constitutes protein surveillance system, plays a pivotal role in the pathobiology of these dementia disorders. Cannabidiol, a non-psychotropic phytocannabinoid of Cannabis sativa, is known for its pleiotropic neuropharmacological effects on the central nervous system, including the ability to abate oxidative stress, neuroinflammation, and protein misfolding. Over the past years, compelling evidence has documented disease-modifying role of cannabidiol in various preclinical and clinical models of neurological disorders, suggesting the potential therapeutic implications of cannabidiol in these disorders. Because of its putative role in the proteostasis network in particular, cannabidiol could be a potent modulator for reversing not only age-associated neurodegeneration but also other protein misfolding disorders. However, the current understanding is insufficient to underpin this proposition. In this review, we discuss the potentiality of cannabidiol as a pharmacological modulator of the proteostasis network, highlighting its neuroprotective and aggregates clearing roles in the neurodegenerative disorders. We anticipate that the current effort will advance our knowledge on the implication of CBD in proteostasis network, opening up a new therapeutic window for ageing proteinopathies.
... CBD reduced tau protein hyperphosphorylation (Casarejos et al., 2013;Aso et al., 2016) and the production of interleukins and nitric oxide in the brain (Iuvone et al., 2009;Walther and Halpern, 2010;Aso et al., 2016). In in vitro models of AD and MS, CBD pretreatment reduced ROS accumulation, mitochondrial dysfunction, lipid peroxidation, caspase-3 levels and DNA fragmentation (Iuvone et al., 2004;Vallée et al., 2017). ...
Cannabidiol (CBD) is a phytocannabinoid with a broad-range of therapeutic potential in several conditions, including neurological (epilepsy, neurodegenerative diseases, traumatic and ischemic brain injuries) and psychiatric disorders (schizophrenia, addiction, major depressive disorder, and anxiety). The pharmacological mechanisms responsible for these effects are still unclear, and more than 60 potential molecular targets have been described. Regarding neuropsychiatric disorders, most studies investigating these mechanisms have focused on neuronal cells. However, glial cells (astrocytes, oligodendrocytes, microglia) also play a crucial role in keeping the homeostasis of the central nervous system. Changes in glial functions have been associated with neuropathological conditions, including those for which CBD is proposed to be useful. Mostly in vitro studies have indicated that CBD modulate the activation of proinflammatory pathways, energy metabolism, calcium homeostasis, and the proliferative rate of glial cells. Likewise, some of the molecular targets proposed for CBD actions are f expressed in glial cells, including pharmacological receptors such as CB1, CB2, PPAR-γ, and 5-HT1A. In the present review, we discuss the currently available evidence suggesting that part of the CBD effects are mediated by interference with glial cell function. We also propose additional studies that need to be performed to unveil the contribution of glial cells to CBD effects in neuropsychiatric disorders.
... Os canabinoides estimulam a remoção do Aβ intraneuronal e bloqueiam a resposta inflamatória, de forma que a toxicidez de peptídeos Aβ pode ser bloqueada pela ativação de receptores canabinoides (Currais, Quehenberger et al. 2016). O canabidiol (CBD) (≥0,1 µM) diminui níveis de ROS e peroxidação lipídica associada à proteína β-amilóide in vitro, além de atenuar a ativação microglial in vitro e in vivo em modelos de AD (Mildew, Mites et al. 2004, Esposito, De Filippis et al. 2006, Martín-Moreno, Reigada et al. 2011. ...
... The beneficial effects of cannabidiol have been described for a wide range of psychiatric disorders, including AD, anorexia nervosa, anxiety, dementia, dystonia, HD, PD, post-traumatic stress disorder (PTSD), psychosis, Tourette syndrome, and depression [119]. It has also exerted a combination of neuroprotective, anti-oxidative, and anti-apoptotic effects against b-amyloid peptide toxicity, effectively decreased reactive oxygen species (ROS) production, lipid peroxidation, caspase 3 levels, DNA fragmentation, and intracellular calcium and thus significantly elevated cell survival as well as prevented amyloid plaque formation associated with late-onset Alzheimer's disease (LOAD) [120,121]. Furthermore, preclinical evidence suggests that cannabinoids may attenuate neurodegeneration by decreasing excitotoxicity ...
Huntington's disease (HD) is an incurable, chronic, progressive, and autosomal-dominant genetic neurodegenerative disorder manifested by abnormal involuntary and voluntary movements, cognitive, and psychiatric disruptions linked with corticostriatal neuronal loss. HD is one of the deadliest diseases commonly affecting older people and the present treatment offers only systematic relief without hindering the onset or ameliorating the disease. 3-Nitropropionic acid (3-NP) treatment mimics HD pathology via striatal degeneration leading to motor and cognitive anomalies. Therefore, striatal neurodegeneration involving a 3-NP model using transgenic animals and expressing mutant proteins is commonly used in preclinical investigations in order to elucidate HD-pathology and explore possible anti-HD therapeutics. In this present review, a number of plant-derived natural products are reported on the basis of their ability as disease-modifying agents active against HD-pathology in various neurotoxic and transgenic animal models via biochemical and molecular modulations of different signaling pathways commonly involving mitochondrial and oxidative stress. Anti-HD activity has been observed for α-mangostin, astragalan, berberine, celastrol, curcumin, galantamine, ginsenosides, hesperidin, lycopene, melatonin, onjisaponin b, protopanaxtriol, resveratrol, S-allylcysteine, sesamol, spermidine, vanillin, etc. These natural compounds alleviated disease pathology via retarding motor dysfunction, autophagy, mitochondrial dysfunction, lipid peroxidation, neuroinflammation, striatal toxicity, and also by promoting antioxidation, mutant protein degradation, motor and cognitive functions, behavioral improvement via modulation of biochemical and molecular signaling pathways, viz., Keap1-Nrf2-ARE pathway, MAPKs and NF-κB pathways, ERK pathway, etc. Moreover, the complex nature and possible synergism of polyherbal formulations containing phytochemicals against the multifactorial nature of HD-pathogenesis have also been discussed. However, very few systematic structure–activity relationship studies have been performed in order to explain the underlying mechanism of action of the natural products against neurodegenerative disorders, such as HD. Limited animal models and overdependence on cellular models are considered as major constraints in evaluating anti-HD natural products. However, the advent of HD transgenic models expressing mutant proteins may facilitate the routine screening of probable anti-HD natural therapeutics besides explaining HD-pathogenesis and more efficacious treatment strategies.
... The cannabis derivatives also have a potent antioxidant property, particularly CBD was shown more protective than a-tocopherol against glutamate neurotoxicity (Hampson et al., 1998). Besides, CBD not only suppressed ROS generation and lipid peroxidation but also reduced caspase 3, (Figure 3) and intracellular calcium levels in Ab-induced PC12 neuronal cells (Iuvone et al., 2004). Furthermore, it also lowered iNOS and NO in similar conditions (Esposito et al., 2006b). ...
Alzheimer’s disease (AD) is an irreversible chronic neurodegenerative disorder that occurs when neurons in the brain degenerate and die. Pain frequently arises in older patients with neurodegenerative diseases including AD. However, the presence of pain in older people is usually overlooked with cognitive dysfunctions. Most of the times dementia patients experience moderate to severe pain but the development of severe cognitive dysfunctions tremendously affects their capability to express the presence of pain. Currently, there are no effective treatments against AD that emphasize the necessity for increasing research to develop novel drugs for treating or preventing the disease process. Furthermore, the prospective therapeutic use of cannabinoids in AD has been studied for the past few years. In this regard, targeting the endocannabinoid system has considered as a probable therapeutic strategy to control several associated pathological pathways, such as mitochondrial dysfunction, excitotoxicity, oxidative stress, and neuroinflammation for the management of AD. In this review, we focus on recent studies about the role of cannabinoids for the treatment of pain and related neuropathological changes in AD.
... It was shown that CBD, acting similarly to the classic antioxidant butylated hydroxytoluene (BHT), prevents dihydrorodamine oxidation in the Fenton reaction [28]. In addition, CBD has been found to decrease β-amyloid formation in neurons by reducing the concentration of transition metal ions [29]. ...
Cannabidiol (CBD) is one of the main pharmacologically active phytocannabinoids of Cannabis sativa L. CBD is non-psychoactive but exerts a number of beneficial pharmacological effects, including anti-inflammatory and antioxidant properties. The chemistry and pharmacology of CBD, as well as various molecular targets, including cannabinoid receptors and other components of the endocannabinoid system with which it interacts, have been extensively studied. In addition, preclinical and clinical studies have contributed to our understanding of the therapeutic potential of CBD for many diseases, including diseases associated with oxidative stress. Here, we review the main biological effects of CBD, and its synthetic derivatives, focusing on the cellular, antioxidant, and anti-inflammatory properties of CBD.
... R. Libro et al. 32 discovered that CBD was involved in the prevention of the expression of proteins potentially involved in tau phosphorylation and Aβ-peptide production. Long-term treatment of transgenic Alzheimer's disease mice with CBD prevented the development of social recognition memory deficits according to D. Cheng et al. 33 Thus, CBD can act in many different ways against neurodegenerative diseases: it can prevent the production of Aβ peptides, and it can probably act on cell membranes, peptide secondary structures, the ability of peptides to aggregate, etc. 30,31 In this work the accent is on the amyloid hypothesis, which says that the development of Alzheimer's and Parkinson's diseases happens due to the aggregation of Aβ peptides in an extracellular space. 34−37 Such aggregates build plaques on cell membranes which cause apoptosis (cell's death) later. ...
In this work cannabidiol (CBD) was investigated as a possible drug against the cytotoxicity of Aβ(31−35) and Aβ(25− 35) peptides with the help of atomistic molecular dynamics (MD) and well-tempered metadynamics simulations. Four interrelated mechanisms of possible actions of CBD are proposed from our computations. This implies that one mechanism can be a cause or/ and a consequence of another. CBD is able to decrease the aggregation of peptides at certain concentrations of compounds in water. This particular action is more prominent for Aβ(25−35), since originally Aβ(31−35) did not exhibit aggregation properties in aqueous solutions. Interactions of CBD with the peptides affect secondary structures of the latter ones. Clusters of CBD are seen as possible adsorbents of Aβ(31−35) and Aβ(25−35) since peptides are tending to aggregate around them. And last but not least, CBD exhibits binding to MET 35. All four mechanisms of actions can possibly inhibit the Aβ-cytotoxicity as discussed in this paper. Moreover, the amount of water also played a role in peptide clustering: with a growing concentration of peptides in water without a drug, the aggregation of both Aβ(31−35) and Aβ(25−35) increased. The number of hydrogen bonds between peptides and water was significantly higher for simulations with Aβ(25−35) at the higher concentration of peptides, while for Aβ(31−35) that difference was rather insignificant. The presence of CBD did not substantially affect the number of hydrogen bonds in the simulated systems.
... Recently, a growing interest has been focused on C. sativa biotypes with low content of Δ 9tetrahydrocannabinol (Δ 9 -THC <0.2%) and with a high titre of nonpsichotropic cannabinoids such as cannabidiol (CBD)/cannabidiolic acid (CBDA) or cannabigerol (CBG)/cannabigerolic acid (CBGA) . This, for a possible use in therapy of Cannabisbased medicinal extracts free of the Δ 9 -THC psychotropic side effects (Iuvone et al., 2004). ...
The aim of this study was to compare the micro‐morphological features of two different non‐drug Cannabis sativa L. biotypes (Chinese accession G‐309 and one fibrante variety) and to evaluate the phytochemical profile as well as some biological properties of the essential oils (EOs) obtained by hydrodistillation of dried flowering tops. After a micro‐morphological evaluation by scanning electron microscopy, the phytochemical composition was analysed by GC–FID and GC–MS analyses. Antioxidant and anti‐acetylcholinesterase properties were investigated by several in vitro cell‐free assays, while neuroactive effects were evaluated on mouse cortical neuronal as well as human iPS cell‐derived central nervous system cells grown on MEA chips. Both EOs showed strong antioxidant properties mainly attributable to the high content of hydroxylated compounds as well as significant anti‐acetylcholinesterase activities (IC50 74.64 and 57.31 μg/ml for Chinese accession and fibrante variety, respectively). Furthermore, they showed a concentration‐dependent inhibition of spontaneous electrical activity of human and mouse neuronal networks, with the fibrante variety, which showed the best activity (MFR, IC50 0.71 and 10.60 μg/ml, respectively). The observed biological activities could be due to a synergic effect between terpenes and phytocannabinoids, although in vivo studies, which clarify the molecular mechanism, are still lacking.
... The beneficial effects of cannabidiol have been described for a wide range of psychiatric disorders, including AD, anorexia nervosa, anxiety, dementia, dystonia, HD, PD, post-traumatic stress disorder (PTSD), psychosis, Tourette syndrome, and depression [119]. It has also exerted a combination of neuroprotective, anti-oxidative, and anti-apoptotic effects against b-amyloid peptide toxicity, effectively decreased reactive oxygen species (ROS) production, lipid peroxidation, caspase 3 levels, DNA fragmentation, and intracellular calcium and thus significantly elevated cell survival as well as prevented amyloid plaque formation associated with late-onset Alzheimer's disease (LOAD) [120,121]. Furthermore, preclinical evidence suggests that cannabinoids may attenuate neurodegeneration by decreasing excitotoxicity ...
... The direction of action of CBD is dependent on the type of cells treated. In the case of fully differentiated cells such as neurons or cardiomyocytes, CBD protects cells against oxidative stress and apoptosis [128,129]. However, CBD intensifies oxidative stress and apoptosis in immune and cancer cells [130][131][132]. ...
Apoptosis is the physiological mechanism of cell death and can be modulated by endogenous and exogenous factors, including stress and metabolic alterations. Reactive oxygen species (ROS), as well as ROS-dependent lipid peroxidation products (including isoprostanes and reactive aldehydes including 4-hydroxynonenal) are proapoptotic factors. These mediators can activate apoptosis via mitochondrial-, receptor-, or ER stress-dependent pathways. Phospholipid metabolism is also an essential regulator of apoptosis, producing the proapoptotic prostaglandins of the PGD and PGJ series, as well as the antiapoptotic prostaglandins of the PGE series, but also 12-HETE and 20-HETE. The effect of endocannabinoids and phytocannabinoids on apoptosis depends on cell type-specific differences. Cells where cannabinoid receptor type 1 (CB1) is the dominant cannabinoid receptor, as well as cells with high cyclooxygenase (COX) activity, undergo apoptosis after the administration of cannabinoids. In contrast, in cells where CB2 receptors dominate, and cells with low COX activity, cannabinoids act in a cytoprotective manner. Therefore, cell type-specific differences in the pro- and antiapoptotic effects of lipids and their (oxidative) products might reveal new options for differential bioanalysis between normal, functional, and degenerating or malignant cells, and better integrative biomedical treatments of major stress-associated diseases.
... On the other hand, studies have indicated that CBD exerts a protective effect on the nervous system by inhibiting neuronal apoptosis [106]. As shown in Fig. 9, caspase activation is the core step leading to apoptosis. ...
... 17 In addition, CBD (10 lM) was reported to reduce the death of neuron-like PC12 cells from 39% to 12% against b-amyloid peptides, and decrease the reactive oxygen species production, lipid peroxidation, intracellular calcium, and caspase-3 levels. 41 Several other compounds have also been studied for potential protection of cortical or hippocampal neurons against H 2 O 2 . [42][43][44] Y-27632, a Rho-associated kinase (ROCK) inhibitor, increased the cell viability to 87% from 66.5% against H 2 O 2 at maximum. ...
Introduction: Reports on the neurotoxic and neuroprotective effects of cannabidiol (CBD) have not been in complete accord, showing different and somewhat contradictory results depending upon the brain cell types and experimental conditions employed. This work systematically examines the neuroprotective capability of CBD against oxidative stress (i.e., hydrogen peroxide [H2O2]) as well as its toxicity profile in the in vitro culture platform of primary hippocampal neurons. Materials and Methods: The low cell-density (100 neurons per mm2) culture was used for analyzing the viability and morphology of neurons at a single-cell level with a confocal laser-scanning microscope (CLSM). Primary neurons were obtained from the hippocampal tissues of embryonic day-18 (E18) Sprague-Dawley rat pups and treated with CBD (0.1-100 μM) and/or H2O2 (0.1-50 μM) at 1 DIV (days in vitro). Results: The lethal concentration 50 (LC50) value (the concentration causing 50% cell death) of CBD was calculated to be 9.85 μM after 24 h of incubation, and that of H2O2 was 2.46 μM under the same conditions. The neuroprotection ratio of CBD against H2O2 ([H2O2]=10 μM) was 2.40 with 5 μM of CBD, increasing the cell viability to 57% from 24%. The CLSM analysis suggested that the cell-death mechanisms were different for CBD and H2O2, and CBD did not completely rescue the morphological alterations of primary hippocampal neurons caused by H2O2, such as neurite degeneration, at least in the in vitro neuron culture. Conclusion: Although CBD showed both neurotoxic and neuroprotective effects on hippocampal neurons in the in vitro setting, the use of low-concentrated (i.e., 5 μM) CBD, not causing toxic effects on the neurons, significantly rescued the neurons from the oxidative stress (H2O2), confirming its neuroprotection capability.
... The beneficial effects of cannabidiol have been described for a wide range of psychiatric disorders, including AD, anorexia nervosa, anxiety, dementia, dystonia, HD, PD, post-traumatic stress disorder (PTSD), psychosis, Tourette syndrome, and depression [119]. It has also exerted a combination of neuroprotective, anti-oxidative, and anti-apoptotic effects against b-amyloid peptide toxicity, effectively decreased reactive oxygen species (ROS) production, lipid peroxidation, caspase 3 levels, DNA fragmentation, and intracellular calcium and thus significantly elevated cell survival as well as prevented amyloid plaque formation associated with late-onset Alzheimer's disease (LOAD) [120,121]. Furthermore, preclinical evidence suggests that cannabinoids may attenuate neurodegeneration by decreasing excitotoxicity ...
Bacopa monnieri (L.) Wettst. (Scrophulariaceae), commonly known as water hyssop, is an extensively used herb in Ayurveda. The bioactive phyto-constituents like the dammarane-type triterpenoid saponins such as bacosides A, B, and C were reported mostly for neuroprotective, nootropic, and memory-enhancing properties. Furthermore, B. monnieri also acts as a natural antioxidant, which can ameliorate morphine dependence, memory deficit in epilepsy, hepatocarcinogenesis, hepatotoxicity, β-amyloid cytotoxicity, inflammation, and oxidative stress (Singh et al., Physiol Plant. 2019). The neuroprotective role of the plant was manifested against neurodegenerative disorders like Parkinson’s disease (PD), Alzheimer’s disease (AD)-associated dementia, attention-deficit hyperactivity disorder in children, and anxiety. Somer report also found the traces of heavy metals in various species of Bacopa monnieri. Inadequate knowledge regarding underlying mechanism of neuroprotection and associated systematic structure-activity relationship (SAR) studies and development of semisynthetic derivatives of saponins are of high importance to facilitate rational designing of novel drugs based on leads from bacopasaponins. This review systematically summarizes the origin, analysis of the pharmacotherapeutic properties, and structural significance of bioactivities exerted by the bacopasaponins. Moreover, future research arenas, lacunae in the present understanding, are also highlighted in this work. Together, this book chapter may further direct to the synthetic optimization of bacopasaponins as lead compounds for the designing of efficacious and clinically acceptable analogues.
... Additionally, a study on a mouse model of AD revealed that Cannabis extract ∆-9-THC-CBD combined in exact ratio reduces Aβ levels and also attenuates learning impairment [124]. An AD rat model was developed by administering Δ-9-THC (3 mg/kg) for 4 weeks, the addition of COX-2 inhibitor decreased the number of Aβ plaques and degenerated new neurons [125]. Thus, following the treatment, the rats showed reduced AD symptoms. ...
Background
Cannabis and its extracts are now being explored due to their huge health benefits. Although, the effect it elicits whether in humans or rodents may vary based on the age of the animal/subject and or the time in which the extract is administered. However, several debates exist concerning the various medical applications of these compounds. Nonetheless, their applicability as therapeutics should not be clouded based on their perceived negative biological actions.
Methodology
Articles from reliable databases such as Science Direct, PubMed, Google scholar, Scopus and Ovid were searched. Specific search methods were employed using multiple keywords: ‘‘Medicinal Cannabis; endocannabinoid system; cannabinoids receptors; cannabinoids and cognition; brain disorders; neurodegenerative diseases’’. For the inclusion/exclusion criteria, only relevant articles related to medicinal cannabis and its various compounds were considered.
Result and conclusion
The current review highlights the role, effects and involvement of cannabis; cannabinoids and endocannabinoids in preventing selected neurodegenerative diseases and possible amelioration of cognitive impairments. Also, cannabis utilization in many disease conditions such as Alzheimer’s and Parkinson’s disease among others. In conclusion, the usage of cannabis should be further explored as accumulating evidence suggests that it could be effective and somewhat safe especially when recommended dosage is adhered to. Furthermore, an in-depth studies should be conducted in order to unravel the specific mechanism underpinning the involvement of cannabinoids at the cellular level and their therapeutic applications.
... The selected plant possess various activities like C. sativa antioxidant activity (Chen et al., 2012). The various parts of the plant are used in the treatment of several diseases, pain, whooping cough, asthma, sedative-hypnotic (Frankhauser et al., 2002) neurodegenerative diseases (Gerra et al., 2010) chemotherapy-induced nausea and vomiting, multiple sclerosis (Vara et al., 2011) anticoagulant (Iuvone et al., 2004) and glaucoma (McAllister et al., 2007) anticancer agents (Levndal et al., 2006;Costa 2004). This study was aimed to evaluate the antioxidant property and H O -induced oxidative stress 2 2 protection activity of the aqueous extract of and C. sativa explore the underlying mechanism of action. ...
... Consequently, natural products, such as cannabidiol (CBD) and tetrahydrocannabinol (THC), have also shown to be effective in vitro and in vivo [184][185][186][187]. In PC12 neuronal cells, CBD has shown protection against oxidative stress, Aβ-induced neurotoxicity, inhi-bition of tau hyperphosphorylation, prevention of proinflammatory gene transcription, and inhibition of Aβ-induced tau hyperphosphorylation [188,189]. In vivo, CBD has shown attenuation of Aβ-induced neuroinflammatory responses by minimizing proinflammatory gene and mediator expression, as well as minimized reactive gliosis [187,190]. ...
Alzheimer’s disease (AD) is an age-related, progressive neurodegenerative disorder characterized by impaired cognition, memory loss, and altered personality. Many of the available pharmaceutical treatments do not alter the onset of disease progression. Recently, alternatives to developed drug candidates have been explored including medicinal plants and herbal treatments for the treatment of AD. This article examines the role of herbal plant extracts and the neuroprotective effects as alternative modes of intervention for AD progression. These extracts contain key metabolites that culminate alterations in AD progression. The traditional plant extracts explored in this article induce a variety of beneficial properties, including antioxidants, anti-inflammatory, and enhanced cognition, while also inducing activity on AD drug targets such as Aβ degradation. While these neuroprotective aspects for AD are relatively recent, there is great potential in the drug discovery aspect of these plant extracts for future use in AD treatment.
... In this study, THC and URB597 (the latter to enhance AEA signaling) were given. Interestingly, THC and URB597 impaired [Iuvone et al., 2004]. Studies using an in vivo model of AD showed that CBD had an anti-infl ammatory action due to a reduction in inducible NO synthase (iNOS) and release of interleukin IL-1β and inhibited hyperphosphorylation of tau protein in PC12 cells, this being a marker for AD . ...
Cannabinoids are natural compounds found in the hemp (Cannabis sativa). Scientific interest in cannabinoids arose after the discovery of the major psychoactive component in hemp, Δ9-tetrahydrocannabinol. Subsequent studies detected receptors in the brain subject to the actions of this compound, along with ligands for these receptors, i.e., endogenous cannabinoids (EC), which make up, along with the enzymes synthesizing, transporting, and degrading them, the endocannabinoid system (ECS). Interest in EC has consistently increased in recent years, especially after their important role in cognitive functions was discovered. They are regulators of synaptic transmission in the brain, mediate numerous forms of plasticity, and control neuron energy metabolism. EC exert influences using a series of mechanisms and interactions with neuromediators, neurotrophic factors, and neuropeptides. The main functions of EC in the brain are retrograde synaptic signaling and neuromodulation, which maintain cellular homeostasis. Information on the influences of cannabinoid drugs on cognitive functions is very contradictory. The cause of this may be that there are still inadequate strictly scientific data from clinical and sociological studies, while in animal experiments different authors use different methods and approaches for actions on the ECS. Thus, effects can differ depending on the substances used, their doses, and routes of administration, and the tasks and experimental conditions selected for testing. There is an extensive literature on the protective effect of ECS activation in neurodegenerative diseases in humans and models of cognitive deficit in animals. This review addresses data providing evidence of the influences of cannabinoid drugs and activation of the EC system on cognitive functions in the normal brain and in neurodegenerative diseases, Alzheimer’s disease, and temporal epilepsy. The possible causes of contradictions in existing data are also discussed.
... No straightforward phenotypic variations towards the cytotoxic or cytoprotective phenotype were instead observed after CBD treatment in both glia cell populations. These results confirm previous studies showing an immunomodulatory effect of CBD on glial cells [41][42][43][44][45], characterized by the reduction in the number of active cells and in the consequent release of pro-inflammatory factors, such as TNFα, COX-2 and iNOS [33,46]. These effects could account for the therapeutic action exerted by CBD in this study. ...
Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the Substantia Nigra pars compacta, leading to classical PD motor symptoms. Current therapies are purely symptomatic and do not modify disease progression. Cannabidiol (CBD), one of the main phytocannabinoids identified in Cannabis Sativa, which exhibits a large spectrum of therapeutic properties, including anti-inflammatory and antioxidant effects, suggesting its potential as disease-modifying agent for PD. The aim of this study was to evaluate the effects of chronic treatment with CBD (10 mg/kg, i.p.) on PD-associated neurodegenerative and neuroinflammatory processes, and motor deficits in the 6-hydroxydopamine model. Moreover, we investigated the potential mechanisms by which CBD exerted its effects in this model. CBD-treated animals showed a reduction of nigrostriatal degeneration accompanied by a damping of the neuroinflammatory response and an improvement of motor performance. In particular, CBD exhibits a preferential action on astrocytes and activates the astrocytic transient receptor potential vanilloid 1 (TRPV1), thus, enhancing the endogenous neuroprotective response of ciliary neurotrophic factor (CNTF). These results overall support the potential therapeutic utility of CBD in PD, as both neuroprotective and symptomatic agent.
... CBD was recently shown to exert a similar effect on H 2 O 2 -induced ROS in intestinal cell monolayers [197]. Furthermore, data from Branca and colleagues (2019) indicate that CBD attenuates neural ROS production following cadmium chloride exposure in a manner similar to to α-tocopheryl acetate [176], and CBD also dose-dependently reduces -amyloid-induced ROS production in neurons [198]. In parallel, CBD has been shown to ameliorate cisplatin-induced production of renal nitrotyrosine in a model of nephrotoxicity [199], and has also been shown to dose-dependently reduce tert-Butyl hydroperoxide-induced ROS production in keratinocytes [184]. ...
Cannabidiol (CBD), one of the primary non-euphoric components in the Cannabis sativa L. plant, has undergone clinical development over the last number of years as a therapeutic for patients with Lennox-Gastaut syndrome and Dravet syndromes. This phytocannabinoid demonstrates functional and pharmacological diversity, and research data indicate that CBD is a comparable antioxidant to common antioxidants. This review gathers the latest knowledge regarding the impact of CBD on oxidative signalling, with focus on the proclivity of CBD to regulate antioxidants and control the production of reactive oxygen species. CBD is considered an attractive therapeutic agent for neuroimmune disorders, and a body of literature indicates that CBD can regulate redox function at multiple levels, with a range of downstream effects on cells and tissues. However, pro-oxidant capacity of CBD has also been reported, and hence caution must be applied when considering CBD from a therapeutic standpoint. Such pro- and antioxidant functions of CBD may be cell- and model-dependent, and may also be influenced by CBD dose, the duration of CBD treatment and the underlying pathology.
... paracetamol), herbal cannabis contains at least 144 compounds referred to as cannabinoids -the most well recognised being tetrahydrocannabinol (THC) and cannabidiol (CBD) (Supplementary Figure 1) . THC is the primary psychoactive compound whereas CBD does not exhibit psychoactive properties, however, both THC and CBD are reported to have applications for medical disorders (Iuvone et al., 2004;Russo and Guy, 2006). The many chemical components in cannabis such as terpenes (Supplementary Figure 1) produce what is referred to as the 'entourage effect' when cannabis is consumed as a naturally occurring mixture of compounds from the raw plant material (Booth et al., 2017;Russo, 2011). ...
Background: Despite rescheduling of cannabis to Schedule 2 and amendments to the law permitting legal availability of cannabis for the treatment of medical conditions, access to cannabis for medical use remains challenging for patients in the United Kingdom (UK). Recreational use is widespread despite laws stating users can be sentenced to prison for up to 5 years for possession.
Objective: The aim of the study was to develop a model for a legal cannabis market in the UK building upon the results of a preceding study in which a UK population sample determined that pharmacies are the most suitable primary legal vendor of cannabis as opposed to regulated shops or the black market.
Methods: An online survey was developed using Qualtrics software and advertised via the Multidisciplinary Association for Psychedelic Studies' Facebook, Twitter and Instagram social media accounts and monthly newsletter.
Results: Three hundred and ninety seven individuals, a majority having used cannabis at least once, consented to participate in the study. The participants concluded that there is enough evidence for cannabis to be prescribed to treat a range of medical conditions. In addition to pharmacies providing cannabis to patients with a prescription, a majority of participants supported cannabis being sold in pharmacies for harm reduction purposes and allowing access to medicinal cannabis in cases where supporting evidence is insufficient to merit a prescription. Participants supported greater integration between dispensing pharmacies and mental health services. Overall, the participants did not oppose a consultation or screening for potential cannabis users prior to obtaining access from licensed vendors. UK participants were supportive of the concept of a cannabis card, which users can present to licensed vendors such as pharmacies, with specific recommendations (such as strains relevant to a patient's medical condition) being coded into the card. A majority of participants supported the existence of shisha-type bars for the purchase and onsite consumption of cannabis and determined that such vendors should not be part of a pharmacy chain of stores or regulated by pharmacy regulators. The participants generally preferred that laws regarding public consumption are in line with existing smoking legislation. Participants determined that it should be legally permitted to grow cannabis at home for personal medical and non-medical purposes but not to sell for profit.
Conclusion: The results are suggestive of a regulatory system that medical and non-medical cannabis users can use which aims to maximise therapeutic applications, minimise harms and respect individual liberty.
... [70]. Dans des modèles cellulaires d'étude de la maladie d'Alzheimer, le CBD s'est montré efficace pour diminuer la mort cellulaire induite par l'accumulation de plaques amyloïdes [71] et inhiber l'hyperphosphorylation de la protéine tau responsable des dégénérescences neurofibrillaires [72]. Le CBD a également diminué le stress oxydant et la neuro-inflammation via les voies de signalisation canoniques des protéines Wnt impliquées dans le contrôle de l'homéostasie neuronale et l'activation des PPAR␥ [73]. ...
Résumé
Objectifs
Dans cet article, nous souhaitons faire le point sur les différentes propriétés du cannabidiol (CBD) potentiellement intéressantes pour le sportif.
Actualités
Le CBD est, avec le Δ9-tetrahydrocannabinol, l’un des phytocannabinoïdes les plus abondants du Cannabis Sativa L. Avec la levée de l’interdiction en 2018 du CBD par l’Agence mondiale anti-dopage, il est probable que les sportifs se tournent davantage vers les produits au CBD dérivés du Cannabis Sativa L.
Perspectives et projets
Des études précliniques sur le CBD ont montré des effets anxiolytiques, analgésiques, anti-inflammatoires, neuroprotecteurs mais également sur le sommeil. Ces propriétés pourraient être intéressantes dans la gestion des blessures, des commotions, de l’anxiété et des troubles du sommeil. Si le CBD paraît être une molécule sûre, les effets secondaires indésirables existent bel et bien et notamment pour les produits non réglementés.
Conclusion
Le manque de preuves scientifiques et le trop peu d’études cliniques appliquées aux sportifs ne permettent pas, pour le moment, de recommander l’utilisation du CBD aux athlètes.
... The selected plant possess various activities like C. sativa antioxidant activity (Chen et al., 2012). The various parts of the plant are used in the treatment of several diseases, pain, whooping cough, asthma, sedative-hypnotic (Frankhauser et al., 2002) neurodegenerative diseases (Gerra et al., 2010) chemotherapy-induced nausea and vomiting, multiple sclerosis (Vara et al., 2011) anticoagulant (Iuvone et al., 2004) and glaucoma (McAllister et al., 2007) anticancer agents (Levndal et al., 2006;Costa 2004). This study was aimed to evaluate the antioxidant property and H O -induced oxidative stress 2 2 protection activity of the aqueous extract of and C. sativa explore the underlying mechanism of action. ...
... It has also be shown that the activation of CB1 receptor by anandamide protects hippocampal neurons from oxidative injury by decreasing intracellular ROS and lowering the expression of type 2 NADPH oxidase -effects that are abolished in the presence of CB1 antagonist AM251 or CB1-siRNA (Jia et al., 2014). Moreover, the non-psychoactive phytocannabinoid, cannabidiol, shows neuroprotection by diminishing ROS levels and lipid peroxidation products in vitro and in vivo in Alzheimer's disease models (Iuvone et al., 2004). With regard to traumatic brain injury, a positive correlation occurs between tetrahydrocannabinol intake and decreased mortality in adult TBI patients (Nguyen et al., 2014) while anandamide-CB1 receptor signaling reduces the progression of clinical symptoms in G93A-SOD1 transgenic mice model of ALS (Bilsland et al., 2006). ...
Free radicals are intricately woven into the fabric of oxidative stress and are significant in the development of neurodegenerative disorders (NDs). This chapter examines free radicals in the context of neurodegeneration and provides overview of the multiple roles they play in the pathophysiology and clinical progression of varying NDs including Pick's disease (PiD), Parkinson's disease (PD), Alzheimer's disease (AD), prion diseases (PrD), traumatic brain injury, and aging. The molecular mechanisms of degeneration in Huntington's disease (HD) are also examined with respect to free radicals. Different antioxidant systems and their mechanisms of action are briefly reviewed in addition to the role of diet in aging. The effectiveness of selected synthetic drugs and natural products used in oxidative stress is also reviewed. Lastly, the chapter examines challenges associated with the use of antioxidants and how promising future directions like the endocannabinoid system is being pursued in the race to effectively manage NDs.
Neuropsychiatric disorders, such as addiction, are associated with cognitive impairment, including learning and memory deficits. Previous research has demonstrated that the chronic use of methamphetamine (METH) induces long-term cognitive impairment and cannabidiol (CBD), as a neuroprotectant, can reverse spatial memory deficits induced by drug abuse. The study aimed to evaluate the effect of CBD on METH-induced memory impairment in rats chronically exposed to METH (CEM). For the induction of CEM, animals received METH (2 mg/kg, twice/day) for 10 days. Thereafter, the effect of intracerebroventricular (ICV) administration of CBD (32 and 160 nmol) during the (10 days) abstinence period on spatial memory was evaluated using the Y-Maze test, while recognition memory was examined using the novel object recognition (NOR) test. The results revealed a significant increase in the motor activity of METH-treated animals compared with the control group and, after the 10-day abstinence period, motor activity returned to baseline. Notably, the chronic administration of METH had impairing effects on spontaneous alternation performance and recognition memory, which was clearly observed in the NOR test. Additionally, although the ICV administration of CBD (160 nmol) could reverse long-term memory, a lower dose (32 nmol) did not result in any significant increase in exploring the novel object during short-term memory testing. These novel findings suggest that the chronic administration of METH induces memory impairment and presents interesting implications for the potential use of CBD in treating impairment deficits after chronic exposure to psychostimulant drugs such as METH.
Background: Phytocannabinoids naturally occur in the cannabis plant (Cannabis sativa), and Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) predominate. There is a need for rapid inexpensive methods to quantify total THC (for statutory definition) and THC-CBD ratio (for classification into three chemotypes). This study explores the capabilities of a spectroscopic technique that combines ultraviolet-visible and fluorescence, absorbance-transmittance excitation emission matrix (A-TEEM). Methods: The A-TEEM technique classifies 49 dry flower extracts into three C. sativa chemotypes, and quantifies the total THC-CBD ratio, using validated gas chromatography (GC)-flame ionization (FID) and High-Performance Liquid Chromatography (HPLC) methods for reference. Multivariate methods used are principal components analysis for a chemotype classification, extreme gradient boost (XGB) discriminant analysis (DA) to classify unknown samples by chemotype, and XGB regression to quantify total THC and CBD content using GC-FID and HPLC data on the same samples. Results: The A-TEEM technique provides robust classification of C. sativa samples, predicting chemotype classification, defined by THC-CBD content, of unknown samples with 100% accuracy. In addition, A-TEEM can quantify total THC and CBD levels relevant to statutory determination, with limit of quantifications (LOQs) of 0.061% (THC) and 0.059% (CBD), and high cross-validation (>0.99) and prediction (>0.99), using a GC-FID method for reference data; and LOQs of 0.026% (THC) and 0.080% (CBD) with high cross-validation (>0.98) and prediction (>0.98), using an HPLC method for reference data. A-TEEM is highly predictive in separately quantifying acid and neutral forms of THC and CBD with HPLC reference data. Conclusions: The A-TEEM technique provides a sensitive method for the qualitative and quantitative characterization of the major cannabinoids in solution, with LOQs comparable with GC-FID and HPLC, and high values of cross-validation and prediction. As a spectroscopic technique, it is rapid, with data acquisition <45 sec per measurement; sample preparation is simple, requiring only solvent extraction. A-TEEM has the sensitivity to resolve and quantify cannabinoids in solution based on their unique spectral characteristics. Discrimination of legal and illegal chemotypes can be rapidly verified using XGB DA, and quantitation of statutory levels of total THC and total CBD comparable with GC-FID and HPLC can be obtained using XBD regression.
Dementia is a group of diseases characterized by gradual impairment of brain function. Alzheimer’s disease is the most common form of dementia and is characterized by many neuropsychiatric symptoms, of which loss of memory is only one and possibly not the most problematic. The pathophysiology of Alzheimer’s disease involves a triad of neuroinflammation, formation of amyloid plaques, and hyperphosphorylation of tau protein. The endocannabinoid system is involved in the pathophysiology of Alzheimer’s disease and, because of this, may be an important therapeutic target in the future. Preclinical and clinical research indicates that cannabidiol, tetrahydrocannabinol, and some of terpenes found in cannabis may be useful in the treatment of the neurobehavioural aspects of the condition. Medicinal cannabis may be a valuable part of a holistic approach to the treatment of AD that considers a range of factors including diet, exercise, stress reduction, and others. This chapter explores the evidence that key phytocannabinoids such as cannabidiol and tetrahydrocannabinol and some of the other phytonutrients of Cannabis sativa may have a role to play in the treatment of this disease that, as yet, has no cure.
Burning mouth syndrome (BMS) is a neuropathic pain disorder associated with a burning sensation on oral mucosal surfaces with frequently reported xerostomia, dysgeusia and tingling or paraesthetic sensations. However, patients present no clinically evident causative lesions. The poor classification of the disorder has resulted in a diagnostic challenge, particularly for the clinician/dentist evaluating these individuals. Major research developments have been made in the BMS field in recent years to address this concern, principally in terms of the pathophysiological mechanisms underlying the disorder, in addition to therapeutic advancements. For the purpose of this review, an update on the pathophysiological mechanisms will be discussed from a neuropathic, immunological, hormonal and psychological perspective. This review will also focus on the many therapeutic strategies that have been explored for BMS, including antidepressants/antipsychotics, nonsteroidal anti-inflammatories, hormone replacement therapies, phytotherapeutic compounds and non-pharmacological interventions, overall highlighting the lack of controlled clinical studies to support the effectiveness of such therapeutic avenues. Particular focus is given to the cannabinoid system, and the potential of cannabis-based therapeutics in managing BMS patients.
Objectives:
This study was to discuss the research trend of dementia treatment using cannabis for the purpose of providing the basis of cannabis use for medical purposes in the future.
Methods:
This study searched publications, which were registered to databases or published by Aug 22, 2019, and targeted the full-text or abstracts of these publications. We selected the final nine studies met all selection criteria.
Results:
These results implied that the CBD components of cannabis might be useful to treat and prevent AD because CBD components could suppress the main causal factors of AD. Moreover, it was suggested that using CBD and THC together could be more useful than using CBD or THC alone.
Conclusion:
We hope that there will be a solid foundation to use cannabis for medical use by continuously evaluating the possibility of using cannabis for clinical purposes as a dementia treatment substance and cannabis can be used as a positive tool.
One of the main non-psychoactive phytocannabinoids of cannabis is cannabidiol (CBD), which has attracted much attention for its neuroprotective roles. The present study was designed to assess whether pretreatment of CBD can attenuate two of the destructive processes of cerebral ischemia, including oxidative stress and cell death. The male rats were randomly divided into 6 main groups (control, MCAO, vehicle, and CBD-treated groups). Using stereotaxic surgery, a cannula was inserted into the right lateral ventricle of the rat brain. CBD was injected at doses of 50, 100 and 200 ng/rat for five consecutive days. After pretreatment, middle cerebral artery (MCA) was blocked for 60 min using the intraluminal filament technique. 24 h after reperfusion, each main group was considered for measurement of infarct volume, superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), p53 gene expression, pathological alterations, and expression of Bax, Bcl-2, cytochrome C, and caspase-3 proteins. The results revealed that CBD at dose of 100 ng/rat reduced the infarction volume and MDA level in cortical and striatal areas of rat brain compared with vehicle group. In addition, the CBD at dose of 100 ng/rat elevated the activity of SOD enzyme in cortex and striatum. The increase in the activity of CAT was also seen at dose of 100 ng/rat in cortex. Furthermore, the Bcl-2/Bax ratio was significantly diminished by the dose of 100 ng/rat CBD in cortex. Moreover, a decrease in expression of cytosolic cytochrome C was observed by CBD at doses of 100 and 200 ng/rat in cortex. CBD at doses 100 and 200 ng/rat also reduced the expression of caspase-3 in cortical and striatal areas, respectively. P53 was downregulated following administration of CBD at dose of 100 ng/rat. Moreover, histological analysis showed the decrease in the percentage of pyknotic neurons in 100 and 200 ng/rat CBD-received groups. CBD played the anti-apoptosis and anti-oxidant roles in cerebral ischemia by affecting the pathways of intrinsic apoptosis, endogenous antioxidant enzymes, and lipid peroxidation.
In the sports domain, cannabis is prohibited by the World Anti-Doping Agency (WADA) across all sports in competition since 2004. The few studies on physical exercise and cannabis focused on the main compound i.e. Δ9-tetrahydrocannabinol. Cannabidiol (CBD) is another well-known phytocannabinoid present in dried or heated preparations of cannabis. Unlike Δ9-tetrahydrocannabinol, CBD is non-intoxicating but exhibits pharmacological properties that are interesting for medical use. The worldwide regulatory status of CBD is complex and this compound is still a controlled substance in many countries. Interestingly, however, the World Anti-Doping Agency removed CBD from the list of prohibited substances – in or out of competition - since 2018. This recent decision by the WADA leaves the door open for CBD use by athletes. In the present opinion article we wish to expose the different CBD properties discovered in preclinical studies that could be further tested in the sport domain to ascertain its utility. Preclinical studies suggest that CBD could be useful to athletes due to its anti-inflammatory, analgesic, anxiolytic, neuroprotective properties and its influence on the sleep-wake cycle. Unfortunately, almost no clinical data are available on CBD in the context of exercise, which makes its use in this context still premature.
Introduction:
Using nanoparticle (NP) drugs can have better effects on the target tissue in various diseases. Alzheimer's disease (AD) is one of the degenerative neurological diseases that due to its high prevalence, requires the use of more appropriate treatments. Therefore, the aim of this study was consideration of the effect of cannabidiol (CBD) coated by nano-chitosan on learning and memory, hippocampal cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 1 (CB2) levels, and amyloid plaques in an AD rat model.
Material and methods:
Thirty-five male Wistar rats were randomly divided into 5 groups (n = 7 in each): control, Alzheimer's disease model that received the beta-amyloid (Aβ) peptide (Alz), Alz + nano-chitosan (NP) Alz + CBD, and Alz + NP + CBD. Alz was induced by injection of the Aβ1-42 peptide into the hippocampal area cornu ammonis1. After confirmation of Alz, 1 μL of CBD and NP + CBD were administered by oral gavage daily in rats for 1 month. The Morris water maze (MWM) test was used to assess learning and memory of animals. Cresyl violet staining was used for consideration of dead cells. Gene and protein expression of CB1 and CB2 was performed by real-time PCR and immunohistochemistry methods.
Results:
Induction of Alz significantly increased Aβ plaques and dead cells compared to the control group (p < 0.001). Results of MWM in the day test show that Alz + NP + CBD significantly decrease escape latency (p < 0.01), travelled distance (p < 0.001), and significantly increased spending time (p < 0.001) compared to the Alz group. Protein expression of CB1 and CB2 significantly increased in Alz + CBD and Alz + NP + CBD compared to the Alz group (p < 0.05).
Conclusion:
It seems that CBD coated by nano-chitosan has good potential for reducing Aβ plaques, increasing brain CB1 and levels CB2, and improving learning and memory in Alz rats.
Introduction
Deposition of amyloid-beta (Aβ) peptide in the brain is the leading source of the onset and progression of Alzheimer's disease (AD). Recent studies have suggested that anti-amyloidogenic agents may be a suitable therapeutic strategy for AD.
Aim
The current review was proposed to address the beneficial effects of cannabis-based drugs for the treatment of AD, focusing primarily on Aβ modifications.
Method
Keywords related to AD, Aβ, and cannabis-based on MeSH were identified and were searched in PubMed, Google Scholar, Scopus, Ovid-Medline, and Web of Science from inception until 15 March 2020. The full text of identified papers was obtained and assessed based on exclusion and inclusion criteria. The review is based on articles that have focused on AD and the amyloidogenic pathway.
Result
A total of 17 studies were identified based on the inclusion criteria; however, nine studies qualified for this systematic review. The maximum and minimum cannabis dosages, mostly CBD and THC in animal studies, were 0.75 and 50 mg/kg, respectively. Cannabis (CBD and THC) was injected for 10 to 21 days. The findings of the 9 articles indicated that cannabis-based drugs might modulate Aβ modifications in several AD models.
Conclusion
Our findings establish that cannabis-based drugs inhibited the progression of AD by modulating Aβ modifications.
Synthetic Cannabinoids (CBs) are a novel class of psychoactive substances that have rapidly evolved around the world with the addition of diverse structural modifications to existing molecules which produce new structural analogues that can be associated with serious adverse health effects. Synthetic CBs represent the largest class of drugs detected by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) with a total of 207 substances identified from 2008 to October 2020, and 9 compounds being reported for the first time. Synthetic CBs are sprayed on natural harmless herbs with an aim to mimic the euphoric effect of Cannabis. They are sold under different brand names including Black mamba, spice, K2, Bombay Blue, etc. As these synthetic CBs act as full agonists at the CB receptors, they are much more potent than natural Cannabis and have been increasingly associated with acute to chronic intoxications and death. Due to their potential toxicity and abuse, the US government has listed some synthetic CBs under schedule 1 classification. The present review aims to provide a focused overview of the literature concerning the development of synthetic CBs, their abuse, and potential toxicological effects including renal toxicity, respiratory depression, hyperemesis syndrome, cardiovascular effects, and a range of effects on brain function.
Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive decline, motor impairments, and accumulation of hallmark proteins, amyloid-beta (Aβ) and tau. Traditionally, transgenic mouse models for AD have focused on Aβ pathology, however, recently a number of tauopathy transgenic models have been developed, including the TAU58/2 transgenic model. Cannabidiol (CBD), a non-toxic constituent of the Cannabis sativa plant, has been shown to prevent and reverse cognitive deficits in Aβ transgenic mouse models of AD. Importantly, the therapeutic properties of CBD on the behavioural phenotype of tauopathy mouse models have not been investigated.
We assessed the impact of chronic CBD treatment (i.e. 50 mg/kg CBD i.p. administration starting 3 weeks prior to behavioural assessments) on disease-relevant behaviours of 4-month-old TAU58/2 transgenic males in paradigms for anxiety, motor functions, and cognition.
TAU58/2 transgenic males demonstrated reduced body weight, anxiety and impaired motor functions. Furthermore, they demonstrated increased freezing in fear conditioning compared to control animals. Interestingly, both sociability and social recognition memory were intact in AD transgenic mice. Chronic CBD treatment did not affect behavioural changes in transgenic males.
In summary, 4-month-old TAU58/2 transgenic males exhibited no deficits in social recognition memory, suggesting that motor deficits and changes in anxiety at this age do not impact on social domains. The moderate increase in fear-associated memory needs further investigation but could be related to differences in fear extinction. Future investigations will need to clarify CBD's therapeutic potential for reversing motor deficits in TAU58/2 transgenic mice by considering alternative CBD treatment designs including changed CBD dosing.
Cannabidiol (CBD) extracts have gained attention for their therapeutic efficacy. The present study used a zebrafish embryo caudal fin amputation model and found 1.25 mg/L crude CBD extract accelerated caudal fin regeneration and reduced apoptosis after amputation, while not altering mitotic regenerating cells. The purity of the CBD extract was 55.5 ± 0.37%. Pure CBD promoted fin regeneration and inhibited neutrophil accumulation in a dose-dependent manner, while these effects were not seen in a high concentration of CBD (2.5 mg/L), possibly due to the toxicity of the high dose. An equivalent amount of pure CBD (0.625 to 1.25 mg/L) enhanced regeneration and reduced apoptosis similarly to crude CBD extract (1.25 mg/L). Additionally, CBD reduced the gene expression level of cxcl8, tnf-a, and il-1β, and protein expression level of IL-1β, Caspase 3, and PARP, but not Bcl-2 or Bax. These results suggest that CBD exerts its effect on wound pro-regeneration in part by modulating the inflammatory response and the IL-1β/Caspase 3/PARP signal pathway.
Cannabidiol (CBD), a phytocannabinoid from the Cannabis sativa plant, exhibits a broad spectrum of potential therapeutic properties for neurodegenerative diseases. An accumulation of amyloid‐β (Aβ) protein is one of the most important neuropathology in neurodegenerative diseases like Alzheimer's disease (AD). Data on the effect of CBD on the amelioration of Aβ‐induced neurite degeneration and its consequences of life and health spans is sparse. This study aimed to investigate the effects of CBD on neurite outgrowth in cells and lifespan and health span in Caenorhabditis elegans (C. elegans). In human SH‐SY5Y neuronal cells, CBD prevented neurite lesion induced by Aβ1‐42 and increased the expression of fatty acid amide hydrolase (FAAH) and cannabinoid receptor 1 (CB1R). Furthermore, CBD both protected the reduction of dendritic spine density and rescued the activity of synaptic Ca2+/calmodulin‐dependent protein kinase II (CaMKII) from Aβ1‐42 toxicity in primary hippocampal neurons. In C. elegans, we used the transgenic CL2355 strain of C. elegans, which expresses the human Aβ peptide throughout the nervous system and found that CBD treatment extended lifespan and improved health span. The neuroprotective effect of CBD was further explored by observing the dopaminergic neurons using transgenic dat‐1: GFP strains using the confocal microscope. This study shows that CBD prevents the neurite degeneration induced by Aβ, by a mechanism involving CB1R activation, and extends lifespan and improves health span in Aβ‐overexpressing worms. Our findings support the potential therapeutic approach of CBD for the treatment of AD patients.
Cannabis and cannabinoid-based products are increasingly being accepted and commodified globally. Yet there is currently limited understanding of the effect of the varied cannabinoid compounds on the brain. Exogenous cannabinoids interact with the endogenous cannabinoid system that underpins vital functions in the brain and body, and are thought to perturb key brain and cognitive function. However, much neuroimaging research has been confined to observational studies of cannabis users, without examining the specific role of the various cannabinoids (THC, CBD etc.). This narrative review summarises the brain structural imaging evidence to date associated with cannabis use, its major cannabinoids (e.g. THC, CBD), and synthetic cannabinoid products that have emerged as recreational drugs. In doing so, we seek to highlight some of the key issues to consider in understanding cannabinoid-related brain effects, emphasizing the dual neurotoxic and neuroprotective role of cannabinoids, and the need to consider the distinct role of the varied cannabinoids in establishing their effect on the brain.
In the last few years research into Cannabis and its constituent phytocannabinoids has burgeoned, particularly in the potential application of novel cannabis phytochemicals for the treatment of diverse illnesses related to neurodegeneration and dementia, including Alzheimer’s (AD), Parkinson’s (PD) and Huntington’s disease (HD). To date, these neurological diseases have mostly relied on symptomatological management. However, with an aging population globally, the search for more efficient and disease-modifying treatments that could delay or mitigate disease progression is imperative. In this context, this review aims to present a state of art in the research with cannabinoids and novel cannabinoid-based drug candidates that have been emerged as novel promising alternatives for drug development and innovation in the therapeutics of a number of diseases, especially those related to CNS-disturbance and impairment.
With the advent of medical cannabis usage globally, there has been a renewed interest in exploring the chemical diversity of this unique plant. Cannabis produces hundreds of unique phytocannabinoids, which not only have diverse chemical structures but also a range of cellular and molecular actions, interesting pharmacological properties, and biological actions. In addition, it produces other flavonoids, stilbenoids, and terpenes that have been variably described as conferring additional or so-called entourage effects to whole-plant extracts when used in therapeutic settings. This review explores this phytochemical diversity in relation to specific bioactivity ascribed to phytocannabinoids as neuroprotective agents. It outlines emergent evidence for the potential for selected phytocannabinoids and other cannabis phytochemicals to mitigate factors such as inflammation and oxidative stress as drivers of neurotoxicity, in addition to focusing on specific interactions with pathological misfolding proteins, such as amyloid β, associated with major forms of neurodegenerative diseases such as Alzheimer’s disease.
The blood brain barrier (BBB) is central to the neurovascular unit (NVU) where it creates a semi-permeable barrier between neuronal tissue and the vascular networks that feed the brain. In neurodegenerative conditions and ischaemic stroke, the BBB becomes compromised and as a result its permeability increases. This not only exacerbates neuronal damage at the site of injury but also causes unwanted extravasation of peripheral immune cells into the brain, fuelling the overactivation of the immune response. Endocannabinoids and phytocannabinoids have both displayed neuroprotective effects, attenuating damage in a range of models including Parkinson’s, Huntington’s, amyloid lateral sclerosis and ischaemic stroke. The current study aimed to investigate the neuroprotective properties of emerging phytocannabinoids; specifically focusing on the BBB and NVU in the context of ischaemic stroke pathophysiology. A four-cell blood brain barrier model was constructed consisting of; human brain microvascular endothelial cells (HBMECs), astrocytes, pericytes and neurons. Cells were cultured on collagen coated transwell inserts and permeability was assessed using transepithelial resistance (TEER). A systematic review was conducted to examine work on the neuroprotective properties of minor phytocannabinoids, aside from cannabidiol (CBD) and delta 9-tetrahydrocannabinol (Δ9-THC). Following on from this, in vitro experiments were conducted using minor phytocannabinoids with the most neuroprotective potential; cannabidivarin (CBDV), cannabigerol (CBG) and cannabidiolic acid (CBDA). Inserts or monocultures (four cell model and pericyte, HBMECs and neuronal monolayers) were subjected to either a 4 h oxygen-glucose deprivation (OGD) protocol or an 8 h OGD (astrocyte monocultures), to model ischaemic stroke in vitro. Media was analysed for various chemokines and cytokines using enzyme-linked immunoassays or multiplex assays. From the systematic review, emerging phytocannabinoids cannabidivarin (CBDV) and cannabigerol (CBG) were found to display efficacy in various neurogenerative conditions and of the limited available mechanistic data, were found to mediate some of their effects through peroxisome proliferator-activated receptor gamma (PPARy). Data showed CBDV (300 nM-10 µM) attenuated MCP-1 levels in HBMEC monolayers, as well as reducing IL-6 (30 nM, 1 µM and 10 µM; p<0.05) and VEGF (10 nM- 10 µM; p<0.01) levels in astrocyte monocultures post OGD. CBG (10 nM-3 µM; p<0.0001) also reduced levels of IL-6 secreted by astrocytes and decreased levels of DNA damage response proteins including Chk1, Chk2, H2A.X and p53 post OGD. Neither CBG, nor CBDV reduced levels of IL-6, VEG or IL-8 in pericytes compared to the vehicle control post OGD. Cannabidiolic acid (CBDA) was also investigated and was found to decrease IL-6 in pericyte monocultures which was mediated, at least in part, by 5-HT1A activation. In a four-cell model of the BBB, CBDA offset increases in permeability vs the vehicle control and offered direct protection to neurons, as shown by a lack of propidium iodide (PI) staining in CBDA treated cells, indicating live cells are present. Data presented in this thesis show minor phytocannabinoids CBDV, CBG and CBDA provide protection against OGD mediated damage, with CBDA also offering protection against increases in permeability of the BBB post OGD. These novel data warrant further investigation into the neuroprotective properties of phytocannabinoids, particularly in ischaemic stroke.
Nervous system disorders are increasing in global prevalence. The prevention and treatment of nervous system disorders by modern medicines are insufficient, facilitating the rapid growth and use of traditional medicines. Plant-derived herbal preparations are used for the well-being and treatment of nervous system disorders by a large proportion of the Sri Lankan population. This ethnopharmacology may be common to the Southeast Asian region, as in Ayurvedic treatments, or endemic to Sri Lanka. While some herbs of benefits to the nervous system are currently under scientific investigation (e.g., Centella asiatica, Bacopa monnieri, Curcuma longa, Withania somnifera), others are less well known (e.g., Celastrus paniculatus, Evolvulus alsinoides, Acorus calamus, Sphaeranthus indicus). Notably, many bioactive components beneficial to the nervous system have been described from “single-herb” preparations. Scientific data on the mechanisms of action of these phytochemicals from herbal plants are available. Further poly-herbal preparations are frequently used in the treatment of neurological disorders or for enhancing nervous system function. The efficacy of these treatments has been demonstrated over the centuries. The compositions of these preparations are discussed in terms of concurrent and synergistic actions, the negation of toxicity, and other features as sometimes described in their formulation. However, many of these preparations require scientific elucidation, where scientific data to determining active ingredients and mechanisms of action are needed. This, together with the growing interest in preventive health, has led to an interest in the health benefits of foods and traditional treatments of nervous system disorders.
High level of detrimental factors including reactive oxygen species (ROS) and inflammatory cytokines accumulated in the infarct core and their erosion to salvageable penumbra are key pathological cascades of ischemia-reperfusion injury in stroke. Few neuroprotectants can remodel the hostile microenvironment of the infarct core for the failure to interfere with dead or biofunctionally inactive dying cells. Even ischemia-reperfusion injury is temporarily attenuated in the penumbra by medications; insults of detrimental factors from the core still erode the penumbra continuously along with drug metabolism and clearance. Herein, a strategy named "nanobuffer" is proposed to neutralize detrimental factors and buffer destructive erosion to the penumbra. Inspired by neutrophils' tropism to the infarct core and affinity to inflammatory cytokines, poly(lactic-co-glycolic acid) (PLGA) nanoparticles are coated with neutrophil membrane to target the infarct core and absorb inflammatory cytokines; α-lipoic acid is decorated on the surface and cannabidiol is loaded for ROS scavenging and neuroprotection, respectively, to construct the basic unit of the nanobuffer. Such a nanobuffer exerts a comprehensive effect on the infarct area via detrimental factor neutralization and cannabidiol-induced neuroprotection. Besides, the nanobuffer can possibly be enhanced by dynamic ROP (ring-opening-polymerization)-induced membrane cross-fusion among closely adjacent units in vivo. Systematic evaluations show significant decrease of detrimental factors in the core and the penumbra, reduced infarct volume, and improved neurological recovery compared to the untreated group of stroke rats.
Background: This study was designed to investigate Saudis' attitudes toward mental distress and psychotropic medication, attribution of causes, expected side effects, and to analyze participants' expectations toward alternative or complementary medicine using aromatic and medicinal plants, through a survey.
Method: The study included 674 participants (citizens and residents in Saudi Arabia) who were randomly contacted via email and social media and gave their consent to complete a questionnaire dealing with 39 items that can be clustered in six parts. Descriptive statistics and Chi-square for cross-tabulation were generated using SPSS.
Results: Among the 664 participants, 73.4% believed that there are some positive and negative outcomes of psychotropic medication. Participants (72.0%) think that the most important reason leading to psychological disorders is mainly due to the loss of a relative or beloved person, and 73.9% considered psychic session as one of the possible treatments of psychological disorders. Surprisingly, only 18.8% of the participants agreed that medicinal and aromatic plants could be a possible treatment of the psychological disorder. Participants (82%) consider that physicians are the most trustful and preferred source of information about alternative and complementary medicine.
Terpenoids, also referred as terpenes have been used extensively in drug related industry due to pharmaceutical properties. These have driven the emergence of studies on terpenoid from plant. Cannabis sativa plant is one of the common natural sources of terpenoids and cannabinoids. The cannabis produces and accumulates terpenoids in grandular trichomes. The grandular trichomes are abundant on the surface of female inflorescence. About 140 terpenoids are known in cannabis and some of them have medicinal potential in treatment of pain, inflammatory, cognition, epilepsy and immune functioning. The biological effect of terpenoid from cannabis is mainly attributed to limonene, myrcene, pinene, linalool, ß-caryophyllene, caryophyllene oxide, nerolidol and phytol. The different composition of terpenoids are responsible in exhibit the unique organoleptic properties and influence the medicinal qualities of difference cannabis strains and varieties. This article aims to review the cannabis plant for terpenoid, terpenoid biosynthesis and its pharmacological activities. The terpenoids from cannabis could be valuable natural resources for drug development.
Inflammation and apoptosis are regulated by similar factors, including ultraviolet B (UVB) radiation and cannabinoids, which are metabolized by cyclooxygenase-2 (COX-2) into pro-apoptotic prostaglandin derivatives. Thus, the aim of this study was to evaluate the impact of cyclooxygenase-2 inhibition by celecoxib on the apoptosis of keratinocytes modulated by UVB, anandamide (AEA) and cannabidiol (CBD). For this purpose, keratinocytes were non-treated/treated with celecoxib and/or with UVB and CBD and AEA. Apoptosis was evaluated using microscopy, gene expressions using quantitate reverse-transcriptase polymerase chain reaction; prostaglandins using liquid chromatography tandem mass spectrometry and cyclooxygenase activity using spectrophotometry. UVB enhances the percentage of apoptotic keratinocytes, which can be caused by the increased prostaglandin generation by cyclooxygenase-2, or/and induced cannabinoid receptor 1/2 (CB1/2) expression. AEA used alone intensifies apoptosis by affecting caspase expression, and in UVB-irradiated keratinocytes, cyclooxygenase-2 activity is increased, while CBD acts as a cytoprotective when used with or without UVB. After COX-2 inhibition, UVB-induced changes are partially ameliorated, when anandamide becomes an anti-apoptotic agent. It can be caused by observed reduced generation of anandamide pro-apoptotic derivative prostaglandin-ethanolamide by COX. Therefore, products of cyclooxygenase-dependent lipid metabolism seem to play an important role in the modulation of UVB-induced apoptosis by cannabinoids, which is particularly significant in case of AEA as inhibition of cyclooxygenase reduces the generation of pro-apoptotic lipid mediators and thus prevents apoptosis.
We have developed a quantitative assay to monitor the oxidative burst (H2O2 production) of polymorphonuclear leukocytes (PMNL) using single cell analysis by flow cytometry, and have examined whether PMNL respond to membrane stimulation with an all-or-none oxidative burst. During incubation with normal neutrophils, dichlorofluorescin diacetate diffused into the cells, was hydrolyzed to 2',7'-dichlorofluorescin (DCFH) and was thereby trapped within the cells. The intracellular DCFH, a nonfluorescent fluorescein analogue, was oxidized to highly fluorescent 2',7'-dichlorofluorescein (DCF) by PMNL stimulated by phorbol myristate acetate (PMA). That the oxidative product was DCF was shown by excitation/emission spectra and by mass spectrometry of the product from PMA-stimulated PMNL. Normal resting and PMA-stimulated PMNL oxidized 6.9 +/- 0.7 and 160 +/- 13 attomoles DCF per cell, respectively, in 15 min. Absence of calcium and magnesium ions and/or addition of 2 mM EDTA did not inhibit DCF formation by PMNL stimulated by 100 ng/ml PMA. Since EDTA prevented aggregation of PMNL (even when stimulated by 100 ng/ml PMA), which would prevent accurate flow cytometric analysis, further experiments were performed with EDTA in the medium. A close correlation between average DCFH oxidation and hexose monophosphate shunt stimulation was demonstrated using cells from patients whose PMNL had oxidative metabolic defects of varying severity. Intracellular DCFH was also oxidized by reagent H2O2 or oxygen derivatives generated by glucose oxidase + glucose or by xanthine oxidase + acetaldehyde; DCFH oxidation by these systems was inhibited by catalase but unchanged by superoxide dismutase. The data indicate that the DCFH oxidation assay is quantitatively related to the oxidative metabolic burst of PMNL, and they strongly suggest that the reaction is mediated by H2O2 generated by the PMNL. Incubation of PMNL with varying concentrations of PMA caused graded responses by all PMNL present; i.e., 1 ng/ml PMA caused a mean response of 34% maximal with a single population of responding PMNL (rather than 66% resting and 34% fully stimulated as predicted by the all-or-none hypothesis). Thus, with these assay conditions, oxidative product formation by PMNL occurs as a graded response to membrane stimulation by PMA.
In phase 1 of the study, 3 mg/kg daily of cannabidiol (CBD) was given for 30 days to 8 health human volunteers. Another 8 volunteers received the same number of identical capsules containing glucose as placebo in a double-blind setting. Neurological and physical examinations, blood and urine analysis, ECG and EEG were performed at weekly intervals. In phase 2 of the study, 15 patients suffering from secondary generalized epilepsy with temporal focus were randomly divided into two groups. Each patient received, in a double-blind procedure, 200-300 mg daily of CBD or placebo. The drugs were administered for along as 4 1/2 months. Clinical and laboratory examinations, EEG and ECG were performed at 15- or 30-day intervals. Throughout the experiment the patients continued to take the antiepileptic drugs prescribed before the experiment, although these drugs no longer controlled the signs of the disease. All patients and volunteers tolerated CBD very well and no signs of toxicity or serious side effects were detected on examination. 4 of the 8 CBD subjects remained almost free of convulsive crises throughout the experiment and 3 other patients demonstrated partial improvement in their clinical condition. CBD was ineffective in 1 patient. The clinical condition of 7 placebo patients remained unchanged whereas the condition of 1 patient clearly improved. The potential use of CBD as an antiepileptic drug and its possible potentiating effect on other antiepileptic drugs are discussed.
beta-Amyloid is a 39- to 43-amino-acid neurotoxic peptide that aggregates to form the core of Alzheimer disease-associated senile (amyloid) plaques. No satisfactory hypothesis has yet been proposed to explain the mechanism of beta-amyloid aggregation and toxicity. We present mass spectrometric and electron paramagnetic resonance spin trapping evidence that beta-amyloid, in aqueous solution, fragments and generates free radical peptides. beta-Amyloid fragments, at concentrations that previously have been shown to be neurotoxic to cultured neurons, can inactivate oxidation-sensitive glutamine synthetase and creatine kinase enzymes. Also, salicylate hydroxylation assays indicate that reactive oxygen species are generated by the beta-amyloid-(25-35) fragment during cell-free incubation. These results are formulated into a free radical-based unifying hypothesis for neurotoxicity of beta-amyloid and are discussed with reference to membrane molecular alterations in Alzheimer disease.
The neuroprotective actions of cannabidiol and other cannabinoids were examined in rat cortical neuron cultures exposed to toxic levels of the excitatory neurotransmitter glutamate. Glutamate toxicity was reduced by both cannabidiol, a nonpsychoactive constituent of marijuana, and the psychotropic cannabinoid (-)Delta9-tetrahydrocannabinol (THC). Cannabinoids protected equally well against neurotoxicity mediated by N-methyl-D-aspartate receptors, 2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid receptors, or kainate receptors. N-methyl-D-aspartate receptor-induced toxicity has been shown to be calcium dependent; this study demonstrates that 2-amino-3-(4-butyl-3-hydroxyisoxazol-5-yl)propionic acid/kainate receptor-type neurotoxicity is also calcium-dependent, partly mediated by voltage sensitive calcium channels. The neuroprotection observed with cannabidiol and THC was unaffected by cannabinoid receptor antagonist, indicating it to be cannabinoid receptor independent. Previous studies have shown that glutamate toxicity may be prevented by antioxidants. Cannabidiol, THC and several synthetic cannabinoids all were demonstrated to be antioxidants by cyclic voltametry. Cannabidiol and THC also were shown to prevent hydroperoxide-induced oxidative damage as well as or better than other antioxidants in a chemical (Fenton reaction) system and neuronal cultures. Cannabidiol was more protective against glutamate neurotoxicity than either ascorbate or alpha-tocopherol, indicating it to be a potent antioxidant. These data also suggest that the naturally occurring, nonpsychotropic cannabinoid, cannabidiol, may be a potentially useful therapeutic agent for the treatment of oxidative neurological disorders such as cerebral ischemia.
REVIEW
Apoptosis, an evolutionarily conserved form of cell suicide, requires specialized machinery. The central component of this
machinery is a proteolytic system involving a family of proteases called caspases. These enzymes participate in a cascade
that is triggered in response to proapoptotic signals and culminates in cleavage of a set of proteins, resulting in disassembly
of the cell. Understanding caspase regulation is intimately linked to the ability to rationally manipulate apoptosis for therapeutic
gain.
Alzheimer’s disease (AD) and Parkinson’s disease are the most common forms of age-related neurodegenerative disorders. The pathogenesis of these and other neurodegenerative diseases remains unclear, and effective treatments are currently lacking. However, recent studies from three diverse disciplines, neuropathology, genetics, and biophysics, have begun to converge on a novel target for therapeutic attack: ordered protein aggregation. Indeed, abnormal protein aggregation characterizes many, if not all, neurodegenerative disorders, not just AD and Parkinson’s disease, but also Creutzfeldt–Jakob disease, motor neuron diseases, the large group of polyglutamine disorders, including Huntington’s disease (1), as well as diseases of peripheral tissue like familial amyloid polyneuropathy (FAP). Many of these deposits were originally identified by their histochemical staining property, hence their designation as amyloid (starch-like). Subsequently, it was learned that amyloid deposits contain extremely insoluble protein fibrils that share similar morphological features (80- to 150-Å fibrils) but comprise many different proteins with no obvious sequence similarity. This review will focus on biophysical studies of protein aggregation in AD and FAP, where mechanistic models connecting pathological and genetic data to clinical disease are beginning to emerge. These two examples illustrate two ends of the biophysical spectrum: in one (AD), a flexible peptide is poised to form fibrils, whereas in the other (FAP), a stable globular tetramer must dissociate and partially unfold before forming a new stable fibril structure.
We have studied the effects of two cannabinoid receptor agonists, WIN 55,212-2 and cannabinol, on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in the C6 glioma cell line. After 24 h of lipopolysaccharide (LPS) (1 microg/mL) and interferon-gamma (IFN-gamma) (300 U/mL) stimulation, a significant increase in NO production, evaluated as nitrite, was observed in the culture medium. WIN 55,212-2 (0.1-10000 nM) and cannabinol (0.3-30000 nM), dose-dependently inhibited nitrite production showing a different potency (WIN 55,212-2 EC(50): 4.2 nM; cannabinol EC(50): 700 nM). WIN 55,212-2 (100 nM), given concomitantly to the stimulus also inhibited iNOS expression but had no effect when added to the cells 2 h after LPS/IFN-gamma, indicating a possible interference at the protein synthesis level or at an earlier step, as gene transcription. The cannabinoid CB1 receptor antagonist, SR141716A (0.1-100 nM), but not the cannabinoid CB2 receptor antagonist, SR144528 (0.1-100 nM), reduced in a dose-related manner WIN 55,212-2-and cannabinol-induced inhibition of nitrite production. SR141161A also reversed the WIN 55,212-2-induced inhibition of iNOS expression. These data suggest that selective cannabinoid CB1 receptor activation, by inhibiting iNOS expression and NO overproduction in glial cells, might be helpful in NO-mediated inflammation leading to neurodegeneration.
The endocannabinoid anandamide [N-arachidonoylethanolamine (AEA)] is thought to function as an endogenous protective factor of the brain against acute neuronal damage. However, this has never been tested in an in vivo model of acute brain injury. Here, we show in a longitudinal pharmacological magnetic resonance imaging study that exogenously administered AEA dose-dependently reduced neuronal damage in neonatal rats injected intracerebrally with the Na(+)/K(+)-ATPase inhibitor ouabain. At 15 min after injury, AEA (10 mg/kg) administered 30 min before ouabain injection reduced the volume of cytotoxic edema by 43 +/- 15% in a manner insensitive to the cannabinoid CB(1) receptor antagonist SR141716A. At 7 d after ouabain treatment, 64 +/- 24% less neuronal damage was observed in AEA-treated (10 mg/kg) rats compared with control animals. Coadministration of SR141716A prevented the neuroprotective actions of AEA at this end point. In addition, (1) no increase in AEA and 2-arachidonoylglycerol levels was detected at 2, 8, or 24 hr after ouabain injection; (2) application of SR141716A alone did not increase the lesion volume at days 0 and 7; and (3) the AEA-uptake inhibitor, VDM11, did not affect the lesion volume. These data indicate that there was no endogenous endocannabinoid tone controlling the acute neuronal damage induced by ouabain. Although our data seem to question a possible role of the endogenous cannabinoid system in establishing a brain defense system in our model, AEA may be used as a structural template to develop neuroprotective agents.
Huperzine A, a novel Lycopodium alkaloid originally discovered in the Chinese herb Qian Ceng Ta (Huperzia serrata), is a reversible, potent, and selective acetylcholinesterase (AChE) inhibitor and has been extensively used for the treatment of Alzheimer's disease (AD) in China. The present studies were designed to investigate effects of huperzine A on amyloid P-peptide fragment 25-35 (Abeta25-35)-induced neuronal apoptosis and potential mechanisms in primary cultured rat cortical neurons. After exposure of the cells to Abeta25-35 (20 muM), apoptotic cell death was observed as evidenced by a significant decrease in cell viability, alteration of neuronal morphology, and DNA fragmentation. Pretreatment of the cells with huperzine A (0.01 -10 muM) prior to Abeta25-35 exposure significantly elevated the cell survival and reduced Abeta25-35-induced nuclei fragmentation. Reactive oxygen species (ROS)-based fluorescence, caspase-3-like fluorogenic cleavage, and Western blot analysis demonstrated that huperzine A reduced Abeta25-35-induced ROS formation in a dose-dependent manner, and 1 muM of huperzine A attenuated Abeta25-35-induced caspase-3 activity at 6, 12, 24, and 48 hr posttreatment. Our results provide the first direct evidence that huperzine A protects neurons against Abeta25-35-induced apoptosis via the inhibition of ROS formation and caspase-3 activity. (C) 2002 Wiley-Liss, Inc.
Abstract Amyloid peptides (AβPs) are implicated in neuronal death associated with Alzheimer's disease. Their toxicity involves disruption cellular Ca2+ homeostasis, leading to activation of caspases and cell death. Antioxidants can prevent such cell death and show beneficial clinical effects in Alzheimer's disease patients. Using the model neurosecretory cell line, PC12, we have shown that AβPs cause enhancement of evoked exocytosis via formation of a Cd2+-resistant Ca2+ influx pathway, and also cause selective, functional up-regulation of current through L-type Ca2+ channels. The involvement of reactive oxygen species (ROS) in these effects were investigated by examining the ability of various antioxidants to interfere with these responses. Both melatonin and ascorbic acid fully blocked the enhancement of catecholamine secretion caused by application of AβP(1−40), as monitored in real time amperometrically, but inhibition of the transcriptional regulator NF-κB with SN-50 did not affect secretion. Enhanced immunofluorescence, observed in AβP-treated cells using a monoclonal antibody raised against the N-terminus of AβP, was also suppressed by melatonin. Ascorbic acid, melatonin and ebselen also fully prevented augmentation of whole-cell Ca2+ currents caused by application of AβP(1−40). By contrast, inhibitors of NF-κB (sulfasalazine and SN-50) were able to prevent AβP induced Ca2+ channel current enhancement, whilst inhibitors of mitogen-activated protein kinase and protein kinase C could not. Our results indicate that augmentation or induction by AβPs of two important, distinct factors regulating Ca2+ homeostasis is mediated by increased ROS production, but only one of these (up-regulation of native Ca2+ channels) requires activation of NF-κB.
Cannabidiol and other cannabinoids were examined as neuroprotectants in rat cortical neuron cultures exposed to toxic levels of the neurotransmitter, glutamate. The psychotropic cannabinoid receptor agonist Δ9-tetrahydrocannabinol (THC) and cannabidiol, (a non-psychoactive constituent of marijuana), both reduced NMDA, AMPA and kainate receptor mediated neurotoxicities. Neuroprotection was not affected by cannabinoid receptor antagonist, indicating a (cannabinoid) receptor-independent mechanism of action. Glutamate toxicity can be reduced by antioxidants. Using cyclic voltametry and a fenton reaction based system, it was demonstrated that Cannabidiol, THC and other cannabinoids are potent antioxidants. As evidence that cannabinoids can act as an antioxidants in neuronal cultures, cannabidiol was demonstrated to reduce hydroperoxide toxicity in neurons. In a head to head trial of the abilities of various antioxidants to prevent glutamate toxicity, cannabidiol was superior to both a-tocopherol and ascorbate in protective capacity. Recent preliminary studies in a rat model of focal cerebral ischemia suggest that cannabidiol may be at least as effective in vivo as seen in these in vitro studies.
β-Amyloid peptide (Aβ), a proteolytic fragment of the β-amyloid precursor protein, is a major component of senile plaques in the brain of Alzheimer's disease patients. This neuropathological feature is accompanied by increased neuronal cell loss in the brain and there is evidence that Aβ is directly neurotoxic. In the present study reduced cell viability in four different neuroblastoma cell types was observed after treatment with human Aβ1–42 for 1 day. Of the cell types tested rat PC12 and human IMR32 cells were most susceptible to Aβ toxicity. Chromosomal condensation and fragmentation of nuclei were seen in PC12, NB2a, and B104 cells but not in IMR32 cells irrespective of their high sensitivity to Aβ. Electrophoretic analysis of cellular DNA confirmed internucleosomal DNA fragmentation typical for apoptosis in all cell types except IMR32. These findings suggest that the form of Aβ-induced cell death (necrosis or apoptosis) may depend on the cell type.
The phosphatidylinositol 3 kinase (PI3K)-Akt/PKB pathway protects neurons from apoptosis caused by diverse stress stimuli. However, its protective role against the amyloid beta peptide (Aβ), a major constituent of Alzheimer's disease plaques, has not been studied. We investigated the effect of the Aβ-derived Aβ(25–35) peptide on apoptosis and on the Akt survival pathway in PC12 cells. Cells submitted to micromolar concentrations of Aβ(25–35) exhibited increased production of reactive oxygen species (ROS) and morphological alterations consistent with apoptosis. Akt1 was activated shortly after incubation with Aβ(25–35) and Aβ(1–40) with a kinetics different to that of nerve-derived growth factor. Akt1 activation was blocked by the PI3K inhibitor wortmannin. We tested the hypothesis that Akt1 might modify the vulnerability of neural cells to apoptosis induced by Aβ(25–35). Overexpression of an active version of Akt1 attenuated the apoptotic effect of Aβ(25–35) as determined by flow cytometry. Moreover, PC12 cells overexpressing a membrane-targeted N-myristylated fusion protein of enhanced green fluorescence protein (EGFP) and mouse Akt1 exhibited lower levels of ROS than control EGFP-transfected cells. The present findings demonstrate that Akt1 is activated in response to Aβ(25–35) in a PI3K-dependent manner and that active Akt1 protects PC12 cells against the pro-apoptotic action of this peptide.
The fragment of β-amyloid comprised of amino acids 25–35 induces a rapid, concentration-dependent increase in cytosolic free calcium levels in suspensions of PC12 neuronal cells. This action of β-amyloid 25–35 is not altered by pretreatment with the calcium channel blockers nifedipine or cobalt, with the depleter of intracellular calcium stores cyclopiazonic acid, or with the phospholipase C inhibitor neomycin. However, the effects of β-amyloid 25–35 on cytosolic free calcium are absent in calcium-free buffer and are blocked by the antioxidant lazaroid U-83836E and by vitamin E. β-Amyloid 25–35 is also neurotoxic and produces a concentration-dependent reduction in the viability of PC12 cells in culture. The neurotoxic action of β-amyloid is blocked by U-83836E and vitamin E but not by nifedipine or cobalt. These data indicate that both the disruption of calcium homeostasis and the reduction of cell viability produced by β-amyloid in PC12 cells are mediated by free radical-based processes.
Deposit of β-amyloid protein (Aβ) in Alzheimer's disease brain may contribute to the associated neurodegeneration. We have studied the neurotoxicity of Aβ in primary cultures of murine cortical neurons, with the aim of identifying pharmacologic ways of attenuating the injury. Exposure of cultures to Aβ (25–35 fragment; 3–25 4mUM) generally triggers slow, concentration-dependent neurodegeneration (over 24–72 h). With submaximal Aβ- (25–35) exposure (10 μM), substantial (>40% within 48 h) degeneration often occurs and is markedly attenuated by the presence of the Ca2+ channel blockers nimodipine (1–20 μM) and Co2+ (100 μM) during the Aβ exposure. However, Aβ neurotoxicity is not affected by the presence of glutamate receptor antagonists. We suggest that Ca2+ influx through voltage-gated Ca2+ channels may contribute to Aβ-induced neuronal injury and that nimodipine and Co2+, by attenuating such influx, are able to attenuate Aβ neurotoxicity.
(−)-Cannabidiol (CBD) is a non-psychotropic component of Cannabis with possible therapeutic use as an anti-inflammatory drug. Little is known on the possible molecular targets of this compound. We investigated whether CBD and some of its derivatives interact with vanilloid receptor type 1 (VR1), the receptor for capsaicin, or with proteins that inactivate the endogenous cannabinoid, anandamide (AEA).
CBD and its enantiomer, (+)-CBD, together with seven analogues, obtained by exchanging the C-7 methyl group of CBD with a hydroxy-methyl or a carboxyl function and/or the C-5′ pentyl group with a di-methyl-heptyl (DMH) group, were tested on: (a) VR1-mediated increase in cytosolic Ca2+ concentrations in cells over-expressing human VR1; (b) [14C]-AEA uptake by RBL-2H3 cells, which is facilitated by a selective membrane transporter; and (c) [14C]-AEA hydrolysis by rat brain membranes, which is catalysed by the fatty acid amide hydrolase.
Both CBD and (+)-CBD, but not the other analogues, stimulated VR1 with EC50=3.2 – 3.5 μM, and with a maximal effect similar in efficacy to that of capsaicin, i.e. 67 – 70% of the effect obtained with ionomycin (4 μM). CBD (10 μM) desensitized VR1 to the action of capsaicin. The effects of maximal doses of the two compounds were not additive.
(+)-5′-DMH-CBD and (+)-7-hydroxy-5′-DMH-CBD inhibited [14C]-AEA uptake (IC50=10.0 and 7.0 μM); the (−)-enantiomers were slightly less active (IC50=14.0 and 12.5 μM). CBD and (+)-CBD were also active (IC50=22.0 and 17.0 μM).
CBD (IC50=27.5 μM), (+)-CBD (IC50=63.5 μM) and (−)-7-hydroxy-CBD (IC50=34 μM), but not the other analogues (IC50>100 μM), weakly inhibited [14C]-AEA hydrolysis.
Only the (+)-isomers exhibited high affinity for CB1 and/or CB2 cannabinoid receptors.
These findings suggest that VR1 receptors, or increased levels of endogenous AEA, might mediate some of the pharmacological effects of CBD and its analogues. In view of the facile high yield synthesis, and the weak affinity for CB1 and CB2 receptors, (−)-5′-DMH-CBD represents a valuable candidate for further investigation as inhibitor of AEA uptake and a possible new therapeutic agent.
British Journal of Pharmacology (2001) 134, 845–852; doi:10.1038/sj.bjp.0704327
Amyloid β protein (Aβ), the central constituent of senile plaques in Alzheimer's disease (AD) brain, is known to exert toxic effects on cultured neurons. The role of the voltage-sensitive Ca2+ channel (VSCC) in β(25–35) neurotoxicity was examined using rat cultured cortical and hippocampal neurons. When L-type VSCCs were blocked by application of nimodipine, β(25–35) neurotoxicity was attenuated, whereas application of ω-conotoxin GVIA (ω-CgTX-GVIA) or ω-agatoxin IVA (ω-Aga-IVA), the blocker for N- or P/Q-type VSCCs, had no effects. Whole-cell patch-clamp studies indicated that the Ca2+ current density of β(25–35)-treated neurons is about twofold higher than that of control neurons. Also, β(25–35) increased Ca2+ uptake, which was sensitive to nimodipine. The 2′,7′-dichlorofluorescin diacetate assay showed the ability of β(25–35) to produce reactive oxygen species. Nimodipine had no effect on the level of free radicals. In contrast, vitamin E, a radical scavenger, reduced the level of free radicals, neurotoxicity, and Ca2+ uptake. These results suggest that β(25–35) generates free radicals, which in turn, increase Ca2+ influx via the L-type VSCC, thereby inducing neurotoxicity.
A thiobarbituric acid (TBA) test procedure with reasonable reproducibility applicable to the assay of lipoperoxides in various animal tissue homogenates is described. It was concluded that the deproteinization of homogenate prior to coloration is not needed, but double wavelength measurement is necessary to avoid interference and the reaction should be performed with phosphoric acid at a definite pH near 2.0. The most reproducible procedure is as follows: To 0.5 ml of 10% homogenate of the tissue sample, add 3 ml of 1% H3PO4 and 1 ml of 0.6% TBA aqueous solution; stir and heat the mixture on a boiling water bath for 45 min. After cooling, add 4 ml of n-butanol, shake, and separate the butanol layer by centrifugation; determine the optical density of the butanol layer at 535 and 520 nm; and calculate the difference of optical density between the two determinations to be taken as the TBA value.
The use of dichlorofluorescin (DCFH) as a measure of reactive oxygen species was studied in aqueous media. Hydrogen peroxide oxidized DCFH to fluorescent dichlorofluorescein (DCF), and the oxidation was amplified by the addition of ferrous iron. Hydrogen peroxide-induced DCF formation in the presence of ferrous iron was completely inhibited by deferoxamine and partially inhibited by ethylenediaminetetraacetic acid, but was augmented by diethylenetriaminepentaacetic acid. Iron-peroxide-induced oxidation of DCFH was partially inhibited by catalase but not by horseradish peroxidase. Nonchelated iron-peroxide oxidation of DCFH was partially inhibited by several hydroxyl radical scavengers, but was independent of the scavenger concentration, and this suggests that free hydroxyl radical is not involved in the oxidation of DCFH in this system. Superoxide anion did not directly oxidize DCFH. Data suggest that H2O2-Fe(2+)-derived oxidant is mainly responsible for the nonenzymatic oxidation of DCFH. In addition, peroxidase alone and oxidants formed during the reduction of H2O2 by peroxidase oxidize DCFH. Since DCFH oxidation may be derived from several reactive intermediates, interpretation of specific reactive oxygen species involved in biological systems should be approached with caution. However, DCFH remains an attractive probe as an overall index of oxidative stress in toxicological phenomena.
In Alzheimer's disease (AD), abnormal accumulations of beta-amyloid are present in the brain and degenerating neurons exhibit cytoskeletal aberrations (neurofibrillary tangles). Roles for beta-amyloid in the neuronal degeneration of AD have been suggested based on recent data obtained in rodent studies demonstrating neurotoxic actions of beta-amyloid. However, the cellular mechanism of action of beta-amyloid is unknown, and there is no direct information concerning the biological activity of beta-amyloid in human neurons. We now report on experiments in human cerebral cortical cell cultures that tested the hypothesis that beta-amyloid can destabilize neuronal calcium regulation and render neurons more vulnerable to environmental stimuli that elevate intracellular calcium levels. Synthetic beta-amyloid peptides (beta APs) corresponding to amino acids 1-38 or 25-35 of the beta-amyloid protein enhanced glutamate neurotoxicity in cortical cultures, while a peptide with a scrambled sequence was without effect. beta APs alone had no effect on neuronal survival during a 4 d exposure period. beta APs enhanced both kainate and NMDA neurotoxicity, indicating that the effect was not specific for a particular subtype of glutamate receptor. The effects of beta APs on excitatory amino acid (EAA)-induced neuronal degeneration were concentration dependent and required prolonged (days) exposures. The beta APs also rendered neurons more vulnerable to calcium ionophore neurotoxicity, indicating that beta APs compromised the ability of the neurons to reduce intracellular calcium levels to normal limits. Direct measurements of intracellular calcium levels demonstrated that beta APs elevated rest levels of calcium and enhanced calcium responses to EAAs and calcium ionophore. The neurotoxicity caused by EAAs and potentiated by beta APs was dependent upon calcium influx since it did not occur in calcium-deficient culture medium. Finally, the beta APs made neurons more vulnerable to neurofibrillary tangle-like antigenic changes induced by EAAs or calcium ionophore (i.e., increased staining with tau and ubiquitin antibodies). Taken together, these data suggest that beta-amyloid destabilizes neuronal calcium homeostasis and thereby renders neurons more vulnerable to environmental insults.
Based on encouraging preliminary findings, cannabidiol (CBD), a major nonpsychotropic constituent of Cannabis, was evaluated for symptomatic efficacy and safety in 15 neuroleptic-free patients with Huntington's Disease (HD). The effects of oral CBD (10 mg/kg/day for 6 weeks) and placebo (sesame oil for 6 weeks) were ascertained weekly under a double-blind, randomized cross-over design. A comparison of the effects of CBD and placebo on chorea severity and other therapeutic outcome variables, and on a Cannabis side effect inventory, clinical lab tests and other safety outcome variables, indicated no significant (p greater than 0.05) or clinically important differences. Correspondingly, plasma levels of CBD were assayed by GC/MS, and the weekly levels (mean range of 5.9 to 11.2 ng/ml) did not differ significantly over the 6 weeks of CBD administration. In summary, CBD, at an average daily dose of about 700 mg/day for 6 weeks, was neither symptomatically effective nor toxic, relative to placebo, in neuroleptic-free patients with HD.
Putative Alzheimer disease (AD)-specific proteins (A68) were purified to homogeneity and shown to be major subunits of one
form of paired helical filaments (PHFs). The amino acid sequence and immunological data indicate that the backbone of A68
is indistinguishable from that of the protein tau (tau), but A68 could be distinguished from normal human tau by the degree
to which A68 was phosphorylated and by the specific residues in A68 that served as phosphate acceptors. The larger apparent
relative molecular mass (Mr) of A68, compared to normal human tau, was attributed to abnormal phosphorylation of A68 because
enzymatic dephosphorylation of A68 reduced its Mr to close to that of normal tau. Moreover, the LysSerProVal motif in normal
human tau appeared to be an abnormal phosphorylation site in A68 because the Ser in this motif was a phosphate acceptor site
in A68, but not in normal human tau. Thus, the major subunits of a class of PHFs are A68 proteins and the excessive or inappropriate
phosphorylation of normal tau may change its apparent Mr, thus transforming tau into A68.
The relationship of microglia and astrocytes to deposits of beta-amyloid protein (BAP) was studied in Alzheimer's disease by immunohistochemistry. BAP was detected in forms varying from diffuse amorphous deposits to compact spherical masses. These latter corresponded in frequency and distribution to senile plaques revealed by Bielschowsky and thioflavine S staining. Approximately half the diffuse deposits had no human leukocyte antigen (HLA)-DR-positive reactive microglia associated with them while nearly all compact deposits had single or multiple HLA-DR-positive reactive microglia embedded in their core. Electron microscopy showed these reactive microglia to be in intimate contact with amyloid fibrils. These data suggest that amyloid deposition may precede the activation of microglia.
A tetrazolium salt has been used to develop a quantitative colorimetric assay for mammalian cell survival and proliferation. The assay detects living, but not dead cells and the signal generated is dependent on the degree of activation of the cells. This method can therefore be used to measure cytotoxicity, proliferation or activation. The results can be read on a multiwell scanning spectrophotometer (ELISA reader) and show a high degree of precision. No washing steps are used in the assay. The main advantages of the colorimetric assay are its rapidity and precision, and the lack of any radioisotope. We have used the assay to measure proliferative lymphokines, mitogen stimulations and complement-mediated lysis.
beta-Amyloid peptide (A beta), a proteolytic fragment of the beta-amyloid precursor protein, is a major component of senile plaques in the brain of Alzheimer's disease patients. This neuropathological feature is accompanied by increased neuronal cell loss in the brain and there is evidence that A beta is directly neurotoxic. In the present study reduced cell viability in four different neuroblastoma cell types was observed after treatment with human A beta 1-42 for 1 day. Of the cell types tested rat PC12 and human IMR32 cells were most susceptible to A beta toxicity. Chromosomal condensation and fragmentation of nuclei were seen in PC12, NB2a, and B104 cells but not in IMR32 cells irrespective of their high sensitivity to A beta. Electrophoretic analysis of cellular DNA confirmed internucleosomal DNA fragmentation typical for apoptosis in all cell types except IMR32. These findings suggest that the form of A beta-induced cell death (necrosis or apoptosis) may depend on the cell type.
Amyloid beta protein (A beta) is a 40-43 amino acid peptide that is associated with plaques in the brains of Alzheimer's patients and is cytotoxic to cultured neurons. Using both primary central nervous system cultures and clonal cell lines, it is shown that a number of anti-oxidants protect cells from A beta toxicity, suggesting that at least one pathway to A beta cytotoxicity results in free radical damage. A beta causes increased levels of H2O2 and lipid peroxides to accumulate in cells. The H2O2-degrading enzyme catalase protects cells from A beta toxicity. Clonal cell lines selected for their resistance to A beta toxicity also become resistant to the cytolytic action of H2O2. In addition, A beta induces the activity of NF-kappa B, a transcription factor thought to be regulated by oxidative stress. Finally, A beta-induced H2O2 production and A beta toxicity are blocked by reagents that inhibit flavin oxidases, suggesting that A beta activates a member of this class of enzymes. These results show that the cytotoxic action of A beta on neurons results from free radical damage to susceptible cells.
Incubation of cultured rat aortic smooth muscle cells (ASMCs) in a medium containing high glucose concentrations (25 mM) did not affect the basal cytosolic free calcium ([Ca2+]i) but led to significant reductions in peak [Ca2+]i response evoked by arginine vasopressin, angiotensin II, and endothelin-1 (ET-1). This was observed in both the presence and absence of extracellular Ca2+. Maintenance of rat ASMCs in a medium containing mannose (an osmotic control for high glucose) did not affect either the basal or peptide agonist-evoked increase in [Ca2+]i. However, pretreatment with either the nonselective protein kinase C (PKC) inhibitor staurosporine or the selective PKC inhibitor 2,6-diamino-N-([1-(1-oxotridecyl)-2 piperidinyl] methyl) hexanamide reversed the attenuating effect of high glucose on peak [Ca2+]i response evoked by ET-1. Also, short-term incubation of ASMCs with the active phorbol ester, phorbol 12-myristate 13-acetate, led to a reduction in peak [Ca2+]i response to all three agonists, whereas the inactive phorbol ester, 4 alpha-phorbol 12,13-didecanoate, which does not activate PKC, had no such effect. Although high-glucose treatment of rat ASMCs led to significant reductions in the maximal number of binding sites to the extent of 39% of [125I]ET-1 specific binding, no significant differences in the affinity (Kd approximately 110 pM) characteristics were evident between control and high-glucose treatment groups. It is proposed that incubation of rat ASMCs with high glucose enhances the de novo synthesis of diacylglycerol and activates membrane-bound PKC and that this, in turn, impairs agonist-mediated intracellular Ca2+ mobilization.