Article

Therapeutic potential of cannabidiol against ischemia/reperfusion liver injury in rats

September 2011
European Journal of Pharmacology 670(1):216-23

DOI:10.1016/j.ejphar.2011.08.048

Source
PubMed

Authors:

Albaha University Faculty of Medicine Albaha Saudi Arabia

The therapeutic potential of cannabidiol, the major non-psychotropic Cannabis constituent, was investigated in rats exposed to ischemia/reperfusion liver injury. Ischemia was induced by clamping the pedicle of the left hepatic lobe for 30 min, and cannabidiol (5mg/kg, i.v.) was given 1h following the procedure and every 24h thereafter for 2 days. Ischemia/reperfusion caused significant elevations of serum alanine aminotransferase and hepatic malondialdehyde, tumor necrosis factor-α and nitric oxide levels, associated with significant decrease in hepatic reduced glutathione. Cannabidiol significantly attenuated the deterioration in the measured biochemical parameters mediated by ischemia/reperfusion. Histopathological examination showed that cannabidiol ameliorated ischemia/reperfusion-induced liver damage. Immunohistochemical analysis revealed that cannabidiol significantly reduced the expression of inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-κB, Fas ligand and caspase-3, and increased the expression of survivin protein in ischemic/reperfused liver tissue. These results emphasize that cannabidiol represents a potential therapeutic option to protect the liver against hypoxia-reoxygenation injury.

Cannabidiol’s Multifactorial Mechanisms Has Therapeutic Potential for Aneurysmal Subarachnoid Hemorrhage: a Review

Article

Full-text available

Sep 2022

Subarachnoid hemorrhage (SAH) is a major health burden that accounts for approximately 5% of all strokes. The most common cause of a non-traumatic SAH is the rupture of a cerebral aneurysm. The most common symptom associated with SAH is a headache, often described as “the worst headache of my life.” Delayed cerebral ischemia (DCI) is a major factor associated with patient mortality following SAH and is often associated with SAH-induced cerebral vasospasm (CV). Cannabidiol (CBD) is emerging as a potential drug for many therapeutic purposes, including epilepsy, anxiety, and pain relief. We aim to review the potential use of CBD as a treatment option for post-SAH critically ill patients. Through a literature review, we evaluated the known pharmacology and physiological effects of CBD and correlated those with the pathophysiological outcomes associated with cerebral vasospasm following subarachnoid hemorrhage. Although overlap exists, data were formatted into three major categories: anti-inflammatory, vascular, and neuroprotective effects. Based on the amount of information known about the actions of CBD, we hypothesize the anti-inflammatory effects are likely to be the most promising therapeutic mechanism. However, its cardiovascular effects through calcium regulation and its neuroprotective effects against cell death, excitotoxicity, and oxidative stress are all plausible mechanisms by which post-SAH critically ill patients may benefit from both early and late intervention with CBD. More research is needed to better understand if and how CBD might affect neurological and vascular functions in the brain following injury such as subarachnoid hemorrhage.

Cannabidiol and Sports Performance: a Narrative Review of Relevant Evidence and Recommendations for Future Research

Article

Full-text available

Jul 2020

Cannabidiol (CBD) is a non-intoxicating cannabinoid derived from Cannabis sativa. CBD initially drew scientific interest due to its anticonvulsant properties but increasing evidence of other therapeutic effects has attracted the attention of additional clinical and non-clinical populations, including athletes. Unlike the intoxicating cannabinoid, Δ9-tetrahydrocannabinol (Δ9-THC), CBD is no longer prohibited by the World Anti-Doping Agency and appears to be safe and well-tolerated in humans. It has also become readily available in many countries with the introduction of over-the-counter "nutraceutical" products. The aim of this narrative review was to explore various physiological and psychological effects of CBD that may be relevant to the sport and/or exercise context and to identify key areas for future research. As direct studies of CBD and sports performance are is currently lacking, evidence for this narrative review was sourced from preclinical studies and a limited number of clinical trials in non-athlete populations. Preclinical studies have observed robust anti-inflammatory, neuroprotective and analgesic effects of CBD in animal models. Preliminary preclinical evidence also suggests that CBD may protect against gastrointestinal damage associated with inflammation and promote healing of traumatic skeletal injuries. However, further research is required to confirm these observations. Early stage clinical studies suggest that CBD may be anxiolytic in "stress-inducing" situations and in individuals with anxiety disorders. While some case reports indicate that CBD improves sleep, robust evidence is currently lacking. Cognitive function and thermoregulation appear to be unaffected by CBD while effects on food intake, metabolic function, cardiovascular function, and infection require further study. CBD may exert a number of physiological, biochemical, and psychological effects with the potential to benefit athletes. However, well controlled, studies in athlete populations are required before definitive conclusions can be reached regarding the utility of CBD in supporting athletic performance.

Xjenza Online Volume 5 Issue 2, 2017

Article

Full-text available

Dec 2017

Xjenza Online

As we get ready to welcome 2018, Xjenza Online will enter a new era under the leadership of the new editor Dr Cristiana Sebu, Associate Professor of Biomathematics at the University of Malta. It is incredible how fast time has gone by as I am now writing my last editorial as the Editor-in-Chief of Xjenza Online. It has been an honour and a privilege for me to have had the opportunity to lead this prestigious Journal, the official organ of the Malta Chamber of Scientists, for the past 5 years. My Editorship has been a rewarding and fulfilling experience. During this time, Xjenza Online has been reborn, grown in size and become the Maltese journal for authoritative reports in all the areas of science. We have published 10 issues, 2 per year, 1 virtual issue on Maltese COST Actions and 1 as Proceedings of the International Mediterranean Neuroscience Conference (MNS2017) held in Malta in 2017. When I look back on my Editorship, I am very proud of what Xjenza Online has achieved and of what it has become. The tremendous growth in science and technology has resulted in a proliferation of high-quality research articles published in Xjenza Online from both Maltese and international Scholars. This, my last issue of Xjenza Online, continues this trend, showcasing some local and international important research and offering several valuable insights into different fields. The issue opens with the contribution by Melanie Grima and colleagues who have reviewed the molecular mechanisms of the sleep wake cycle with the aim of finding some therapeutic applications for insomnia. Gabriella Gatt et al., show that the prevalence of an easily preventable tooth condition such as erosive tooth wear is high in school aged Maltese children. Brockdorff and Bernice Amaira produce an estimate for human capital stock for Malta over the period 2005 to 2013 and compare Malta’s performance with that of other countries. Emanuele Colica et al., present a 3D digital model of Ramla Bay (Gozo) obtained by using photograms taken from drones useful for monitoring the dynamics of the beach-dune system and the characterization of the coast for the mitigation of coastal erosion. Jennifer Fiorentino present a revised appraisal of Lichens of the Maltese Islands described by S. Sommier and A. Caruana Gatto in 1915. Yanica Ellul and Katya De Giovanni report on the social impact of the American University of Malta’s Cospicua site on the Cottonera and the surrounding localities. The selection contains three commentaries. Manuela Radic and colleagues’ contribution from Malta and Palermo, Italy focused on liver diseases induced by alcohol, cannabinoids and nicotine; Tiziana M. Florio from L`Aquila, Italy gives her view of Parkinson’s Disease motor disorganization and temporal processing and finally Cristiana Sebu has revised the application of the Electrical Impedance Mammography for low-cost, portable and non-invasive breast cancer screening. The collection ends with 6th Annual Science in the House Exhibition by David C. Magri. The success of this Journal would not have been possible without the involvement, commitment, and support from a large group of associates and colleagues. First, I would like to thank Professor Alex Felice for his trust and support. Then, there are the Associate Editors, without their important work, it would not be possible to maintain the Journal's high standards of publication. Additionally, I take this opportunity to thank my visiting students from Cardiff University who have served as Editorial Assistants during these years (Stephanie in 2013, Caitlin 2014, Magdalena 2015, Katie and Amber 2016, Katie and Sunneth 2017) and above all Dr Jackson Said the Managing Editor and the copy editors William Hicklin and Gabriel Farrugia. Last but not least, the continued success of this Journal is only possible through the combined cooperation of authors and reviewers. Without their contributions, there would be no Xjenza Online! I am grateful to the authors for their high-standard of work and to the reviewers for their crucial help in the peer-review process. In turning the reins over to the new Editor-in-Chief, with great hopes I look forward to the future of Xjenza Online and I wish all the best to the new editorial team. The new Xjenza Online will continue to make every effort to improve content and wide fields, for the benefit of our readers and all others interested in the recent development in the different branches of science in Malta and abroad. It is now time to pass the baton to the new Editor and to conclude my last Editorial, but this is not my final farewell to Xjenza. Indeed, I have been asked to act as Publication Manager for the Chamber of Scientists to continue supporting the new Editors behind the scenes in furthering the success of Xjenza Online. Giuseppe Di Giovanni Editor-in Chief of Xjenza Online December 2017

Information for Healthcare Professionals: Cannabis and the Cannabinoids (2013)

Research

Full-text available

May 2016

Hanan Abramovici

This research monograph is a peer-reviewed summary of the scientific evidence on the uses and harms of cannabis and cannabinoids for medical purposes.

The effect of endocannabinoid system in ischemia-reperfusion injury: a friend or a foe?

Article

May 2015

The effect of endocannabinoid system in ischemia-reperfusion injury: A friend or a foe?

Article

May 2015

Introduction: In recent years, the endocannabinoid system has emerged as a new therapeutic target in variety of disorders associated with inflammation and tissue injury, including those of the neuronal, liver, renal and cardiovascular system. The aim of the present review is to elucidate the effect of endocannabinoid system on ischemia reperfusion injury (IRI) in different organs and systems. Areas covered: The MEDLINE/PubMed database was searched for publications with the medical subject heading Cannabinoids* (CBs), CB receptors*, organ*, ischemia/reperfusion injury*, endocannabinoid* and system*. The initial relevant studies retrieved from the literature were 91 from PubMed. This number was initially limited to 35, after excluding the reviews and studies reporting data for receptors other than cannabinoid. Expert opinion: CB2 receptors may play an important compensatory role in controlling tissue inflammation and injury in cells of the neuronal, cardiovascular, liver and renal systems, as well as in infiltrating monocytes/macrophages and leukocytes during various pathological conditions of the systems (atherosclerosis, restenosis, stroke, myocardial infarction, heart, liver and renal failure). These receptors limit inflammation and associated tissue injury. On the basis of preclinical results, pharmacological modulation of CB2 receptors may hold a unique therapeutic potential in stroke, myocardial infarction, atherosclerosis, IRI and liver disease.

Effects of iNOS in Hepatic Warm Ischaemia and Reperfusion Models in Mice and Rats: A Systematic Review and Meta-Analysis

Article

Full-text available

Oct 2022
INT J MOL SCI

Warm ischaemia is usually induced by the Pringle manoeuver (PM) during hepatectomy. Currently, there is no widely accepted standard protocol to minimise ischaemia-related injury, so reducing ischaemia-reperfusion damage is an active area of research. This systematic review and meta-analysis focused on inducible nitric oxide synthase (iNOS) as an early inflammatory response to hepatic ischaemia reperfusion injury (HIRI) in mouse- and rat-liver models. A systematic search of studies was performed within three databases. Studies meeting the inclusion criteria were subjected to qualitative and quantitative synthesis of results. We performed a meta-analysis of studies grouped by different HIRI models and ischaemia times. Additionally, we investigated a possible correlation of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) regulation with iNOS expression. Of 124 included studies, 49 were eligible for the meta-analysis, revealing that iNOS was upregulated in almost all HIRIs. We were able to show an increase of iNOS regardless of ischemia or reperfusion time. Additionally, we found no direct associations of eNOS or NO with iNOS. A sex gap of primarily male experimental animals used was observed, leading to a higher risk of outcomes not being translatable to humans of all sexes.

Cannabidiol attenuates alcohol-induced liver steatosis, metabolic dysregulation, inflammation and neutrophil-mediated injury

Article

Full-text available

Sep 2017

Cannabidiol (CBD) is a non-psychoactive component of marijuana, which has anti-inflammatory effects. It has also been approved by FDA for various orphan diseases for exploratory trials. Herein, we investigated the effects of CBD on liver injury induced by chronic plus binge alcohol feeding in mice. CBD or vehicle was administered daily throughout the alcohol feeding study. At the conclusion of the feeding protocol, serums samples, livers or isolated neutrophils were utilized for molecular biology, biochemistry and pathology analysis. CBD significantly attenuated the alcohol feeding-induced serum transaminase elevations, hepatic inflammation (mRNA expressions of TNFα, MCP1, IL1β, MIP2 and E-Selectin, and neutrophil accumulation), oxidative/nitrative stress (lipid peroxidation, 3-nitrotyrosine formation, and expression of reactive oxygen species generating enzyme NOX2). CBD treatment also attenuated the respiratory burst of neutrophils isolated from chronic plus binge alcohol fed mice or from human blood, and decreased the alcohol-induced increased liver triglyceride and fat droplet accumulation. Furthermore, CBD improved alcohol-induced hepatic metabolic dysregulation and steatosis by restoring changes in hepatic mRNA or protein expression of ACC-1, FASN, PPARα, MCAD, ADIPOR-1, and mCPT-1. Thus, CBD may have therapeutic potential in the treatment of alcoholic liver diseases associated with inflammation, oxidative stress and steatosis, which deserves exploration in human trials.

Cannabidiol Protects againstChronic Plus Binge Alcohol Induced Liver Injury by Modulating Neutrophil Infiltration, E Selectin, Inflammation and Oxidative/Nitrative Stress

Article

Full-text available

Nov 2014
FREE RADICAL BIO MED

Cannabidiol Rescues Acute Hepatic Toxicity and Seizure Induced by Cocaine

Article

Full-text available

Apr 2015
MEDIAT INFLAMM

Cocaine is a commonly abused illicit drug that causes significant morbidity and mortality. The most severe and common complications are seizures, ischemic strokes, myocardial infarction, and acute liver injury. Here, we demonstrated that acute cocaine intoxication promoted seizure along with acute liver damage in mice, with intense inflammatory infiltrate. Considering the protective role of the endocannabinoid system against cell toxicity, we hypothesized that treatment with an anandamide hydrolysis inhibitor, URB597, or with a phytocannabinoid, cannabidiol (CBD), protects against cocaine toxicity. URB597 (1.0 mg/kg) abolished cocaine-induced seizure, yet it did not protect against acute liver injury. Using confocal liver intravital microscopy, we observed that CBD (30 mg/kg) reduced acute liver inflammation and damage induced by cocaine and prevented associated seizure. Additionally, we showed that previous liver damage induced by another hepatotoxic drug (acetaminophen) increased seizure and lethality induced by cocaine intoxication, linking hepatotoxicity to seizure dynamics. These findings suggest that activation of cannabinoid system may have protective actions on both liver and brain induced by cocaine, minimizing inflammatory injury promoted by cocaine, supporting its further clinical application in the treatment of cocaine abuse.

MICROSCOPIC ARCHITECTURE OF THE LIVER OF EXPERIMENTAL RATS AFTER CANNABIDIOL OIL APPLICATIONS

Article

Sep 2023

Cannabidiol (CBD), found in Cannabis sativa (hemp), is a non-psychoactive phytochemical substance that has gained considerable popularity over the past decade. Cannabidiol is the main phytocannabinoid, its share in the plant extract can reach 40%. The aim of the study was to study and compare the microscopic architecture of the liver in normal and after 2 weeks cannabidiol oil applications in experimental rats. We conducted an experimental study of the effect of CBD on the liver 2 weeks after its use as a dietary supplement. The main group consisted of 18 rats to which 5 drops (3 mg 10%) of cannabidiol oil were added to the main feed once a day for 2 weeks. The control group consisted of 6 sexually mature white male rats, which were provided with water and food without any restrictions. Our research results showed that the use of CBD oil as a food supplement did not have a toxic effect on the liver, did not cause any damage.

The Effects of Cannabidiol, a Non-Intoxicating Compound of Cannabis, on the Cardiovascular System in Health and Disease

Article

Full-text available

Sep 2020
INT J MOL SCI

Cannabidiol (CBD) is a non-intoxicating and generally well-tolerated constituent of cannabis which exhibits potential beneficial properties in a wide range of diseases, including cardiovascular disorders. Due to its complex mechanism of action, CBD may affect the cardiovascular system in different ways. Thus, we reviewed the influence of CBD on this system in health and disease to determine the potential risk of cardiovascular side effects during CBD use for medical and wellness purposes and to elucidate its therapeutic potential in cardiovascular diseases. Administration of CBD to healthy volunteers or animals usually does not markedly affect hemodynamic parameters. Although CBD has been found to exhibit vasodilatory and antioxidant properties in hypertension, it has not affected blood pressure in hypertensive animals. Hypotensive action of CBD has been mainly revealed under stress conditions. Many positive effects of CBD have been observed in experimental models of heart diseases (myocardial infarction, cardiomyopathy, myocarditis), stroke, neonatal hypoxic ischemic encephalopathy, sepsis-related encephalitis, cardiovascular complications of diabetes, and ischemia/reperfusion injures of liver and kidneys. In these pathological conditions CBD decreased organ damage and dysfunction, oxidative and nitrative stress, inflammatory processes and apoptosis, among others. Nevertheless, further clinical research is needed to recommend the use of CBD in the treatment of cardiovascular diseases.

Effects of cannabinoid receptor 2 synthetic agonist, AM1241, on bleomycin induced pulmonary fibrosis

Article

Full-text available

Jun 2020

Bleomycin (BLM) is a chemotherapeutic agent that can cause pulmonary fibrosis. Little is known about the possible protective role of the CB2 receptor agonist, AM1241. We investigated the effects of CB2 receptor activation by AM1241 on BLM induced lung fibrosis in a rat model. BLM was administered via the trachea. Adult female Wistar rats were divided into five groups: saline (control group), BLM (BLM group), CB2 agonist (AM1241) + BLM (BLMA group), CB2 antagonist (AM630) and CB2 agonist (AM1241) + BLM (BLMA + A group), and vehicle (dimethylsulfoxide) + BLM (BLM + vehicle group). Hydroxyproline, collagen type 1, total protein, glutathione (GSH), malondialdehyde (MDA), interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels were measured in lung fibrosis and control tissue using standard methods. We investigated the histopathology of lung tissue to determine the extent of fibrosis. We found significantly higher levels of hydroxyproline, TNF-α, IL-6 and total protein in the BLM group compared to the BLMA group. The level of GSH also was higher in the BLMA group compared to the BLM group. Inflammation and fibrotic changes were significantly reduced in the BLMA group. Our findings suggest that CB2 receptor activation provided protection against BLM induced pulmonary fibrosis by suppressing oxidative stress and increasing cytokines.

Cannabidiol (CBD) in Dietary Supplements: Perspectives on Science, Safety, and Potential Regulatory Approaches

Article

Jun 2020

The proliferation in the last few years of cannabidiol (CBD)-containing products in the U.S. markets has been greatly accelerated by changes in the regulatory environment, and by perceptions of their health benefits and presumed safety. The result has been aggressive marketing of many types of products, some of dubious quality, making or implying drug-type claims. The recent approval by the U.S. Food and Drug Administration (FDA) of CBD in the form of Epidiolex®, further complicates the regulatory picture. In addition, a number of studies suggest that, at least at high doses, there may be serious adverse effects or drug interactions associated with CBD. At present, CBD-containing products do not meet the strict definition of dietary supplements, but the FDA is continuing to consider some framework under which they might be allowed. Meanwhile, FDA has adopted a “risk-based” enforcement policy. Possible approaches to a new framework for regulation of CBD products as dietary supplements are discussed here, including expanded research emphasis, a robust corporate stewardship program, and a rigorous adverse event reporting program.

Cannabinoids and the Microbiota-Gut-Brain-Axis: Emerging Effects of Cannabidiol and Potential Applications to Alcohol Use Disorders

Article

Full-text available

Dec 2019
ALCOHOL CLIN EXP RES

The endocannabinoid system (ECS) has emerged in recent years as a potential treatment target for alcohol use disorders (AUD). In particular, the non-psychoactive cannabinoid cannabidiol (CBD) has shown preclinical promise in ameliorating numerous clinical symptoms of AUD. There are several proposed mechanism(s) through which cannabinoids (and CBD in particular) may confer beneficial effects in the context of AUD. First, CBD may directly impact specific brain mechanisms underlying AUD to influence alcohol consumption and the clinical features of AUD. Second, CBD may influence AUD symptoms through its actions across the digestive, immune, and central nervous systems, collectively known as the microbiota-gut-brain-axis (MGBA). Notably, emerging work suggests that alcohol and cannabinoids exert opposing effects on the MGBA. Alcohol is linked to immune dysfunction (e.g., chronic systemic inflammation in the brain and periphery) as well as disturbances in gut microbial species (microbiota) and increased intestinal permeability. These MGBA disruptions have been associated with AUD symptoms such as craving and impaired cognitive control. Conversely, existing preclinical data suggest that cannabinoids may confer beneficial effects on the gastrointestinal and immune system, such as reducing intestinal permeability, regulating gut bacteria and reducing inflammation. Thus, cannabinoids may exert AUD harm-reduction effects, at least in part, through their beneficial actions across the MGBA. This review will provide a brief introduction to the ECS and the MGBA, discuss the effects of cannabinoids (particularly CBD) and alcohol in the brain, gut, and immune system (i.e., across the MGBA), and put forth a theoretical framework to inform future research questions.

Cannabis in liver disorders: a friend or a foe?

Article

Aug 2018
EUR J GASTROEN HEPAT

The recent legalization of recreational marijuana use in some parts of the world, the discovery of new indications for the clinical application of cannabis, and the acceptance of the use of cannabis in practice has been paralleled by extensive research on the active components of cannabis and the endocannabinoid system within the human body. In this review, we evaluate the available evidence on cannabis and its constituents and the application of this evidence in clinical practice, focusing particularly on the liver and liver diseases. Constituents of cannabis, such as cannabidiol and Δ-tetrahydrocannabinol, have shown anti-inflammatory, antioxidant, and hepatoprotective effects both in in vitro and clinical studies, and appear to have potential in the symptom management and treatment of various liver diseases that were previously considered difficult to manage conservatively. In addition, the manipulation of the inherent endocannabinoid response system has found favor in many clinical fields and has generated considerable research and clinical interest. Moreover, evidence with regard to the adverse effects of marijuana use in liver diseases is weak, which has led to raise a question on the prior rules, with regard to a denial of liver transplantation to marijuana users. All in all, the recent trends in research, clinical experiences, as well as the legislature, has opened up new avenues towards the widespread clinical application of cannabis and its derivatives as well as modifiers of the components of the endocannabinoid system. More research is required to fully exploit these new evidences.

Untargeted rat brain metabolomics after oral administration of a single high dose of cannabidiol

Article

Full-text available

Aug 2018
J PHARMACEUT BIOMED

Cannabidiol (CBD), for long time considered as a minor cannabinoid of Cannabis sativa, has recently gained much attention due to its antioxidant, anti-inflammatory, analgesic and anticonvulsant properties. A liquid chromatography coupled to mass spectrometry based method was developed for the quantitative determination of CBD and other cannabinoids (Δ9-tetrahydrocannabinol (THC), 11-hydroxy-THC and 11-nor-9-carboxy-THC) in rat brain samples after oral administration of a single high dose (50 mg/kg) of CBD. The main challenge of the present work was to study CBD pharmacokinetics in rat cortex: the identification of its metabolites and pharmacodynamics through the study of variations in endogenous compounds' concentrations following CBD administration. An untargeted metabolomics approach revealed the formation of some CBD metabolites that are not commonly found in other body tissues or fluids. Lastly, the changes in some endogenous compounds' concentrations were correlated with some of the pharmacological properties of this cannabinoid.

The Cannabinoids Switch of Oxidative Stress: A Double-Edged Sword

Article

Full-text available

Dec 2013

Oxidative Stress, deriving from a perturbation of the cellular balance between pro-oxidant and anti-oxidant molecules, has been involved in the patho-physiology of multiple diseases, and anti-oxidant supplementation are largely studied for therapeutic purposes. The Cannabis sativa derivates, the cannabinoids (CBs), are widely used as a recreational drug, but pharmacological activities also prompt to therapeutic use. Exposure to CBs rises physical and psychic effects which can evolve in both short-term and long-term toxicity. High inter-individual variation exists in the susceptibility to these effects. Many evidences show a complex modulator action of CBs on cellular oxidative stress, with different outcomes according to cellular type, microenvironment, time and dose of exposition. The subtle balance between anti-oxidant or pro-oxidant action of CBs should be taken into account to achieve a more accurate comprehension of the molecular mechanisms involved in toxicity, considering that OS is not merely a damaging factor, but is also involved in protective pathways.

Effect of selective versus non-selective cyclooxygenase inhibitors on ischemia-reperfusion-induced hepatic injury in rats

Article

May 2015

Aim Ischemia reperfusion (IR) injury represents an important pathological process of liver injury during major hepatic surgery. The role of cyclooxygenase (COX) enzymes in the pathogenesis of ischemia-reperfusion (IR)-induced liver injury is not clear. This study investigated the effect of selective COX-2 inhibitor, celecoxib, versus non-selective, indomethacin, on hepatic IR injury in rats. Hepatic IR was induced in adult male rats. The animals were divided into 4 groups: normal control (sham group), IR non-treated group; IR- indomethacin-treated group; and IR- celecoxib-treated group. Liver injury was evaluated by serum alanine aminotransferase (ALT) and histopathological examination of liver tissues. Hepatic tissue content of oxidative stress parameters glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, malondialdehyde (MDA), nitric oxide (NO) and the inflammatory marker, tumor necrosis factor-alpha, (TNF-α) were measured. Moreover, the immunohistochemical detection of endothelial NO synthase (eNOS), inducible NO synthase (iNOS), and caspase-3 in hepatic tissue was performed. Celecoxib, but not indomethacin, significantly attenuated hepatic IR injury as evidenced by reduction in serum ALT as well as by improvement in the histopathological scoring. Such effect was associated with attenuation in oxidative stress and TNF-α, along with modulation of immunohistochemical expression of eNOS, iNOS and caspase-3 in hepatic tissue. The present study concluded that selective COX-2 inhibition (but not non-selective), is hepatoprotective against liver IR injury; indicating a differential role of COX-1 versus COX-2. Modulation of iNOS, eNOS and caspase-3 might participate in the protective effect of selective COX-2-inhibitors. Copyright © 2015. Published by Elsevier Inc.

Protective Effects of Cannabidiol on Lesion-Induced Intervertebral Disc Degeneration

Article

Full-text available

Dec 2014
PLOS ONE

Disc degeneration is a multifactorial process that involves hypoxia, inflammation, neoinnervation, accelerated catabolism, and reduction in water and glycosaminoglycan content. Cannabidiol is the main non-psychotropic component of the Cannabis sativa with protective and anti-inflammatory properties. However, possible therapeutic effects of cannabidiol on intervertebral disc degeneration have not been investigated yet. The present study investigated the effects of cannabidiol intradiscal injection in the coccygeal intervertebral disc degeneration induced by the needle puncture model using magnetic resonance imaging (MRI) and histological analyses. Disc injury was induced in the tail of male Wistar rats via a single needle puncture. The discs selected for injury were punctured percutaneously using a 21-gauge needle. MRI and histological evaluation were employed to assess the results. The effects of intradiscal injection of cannabidiol (30, 60 or 120 nmol) injected immediately after lesion were analyzed acutely (2 days) by MRI. The experimental group that received cannabidiol 120 nmol was resubmitted to MRI examination and then to histological analyses 15 days after lesion/cannabidiol injection. The needle puncture produced a significant disc injury detected both by MRI and histological analyses. Cannabidiol significantly attenuated the effects of disc injury induced by the needle puncture. Considering that cannabidiol presents an extremely safe profile and is currently being used clinically, these results suggest that this compound could be useful in the treatment of intervertebral disc degeneration.

Is the cardiovascular system a therapeutic target for CBD?

Article

Jun 2012
BRIT J CLIN PHARMACO

Cannabidiol (CBD) has beneficial effects in disorders as wide ranging as diabetes, Huntington's disease, cancer and colitis. Accumulating evidence now also suggests that CBD is beneficial in the cardiovascular system. CBD has direct actions on isolated arteries, causing both acute and time-dependent vasorelaxation. In vitro incubation with CBD enhances the vasorelaxant responses in animal models of impaired endothelium-dependent vasorelaxation. CBD protects against the vascular damage caused by a high glucose environment, inflammation, or the induction of type 2 diabetes in animal models, and reduces the vascular hyperpermeability associated with such environments. A common theme throughout these studies is the anti-inflammatory and anti-oxidant effect of CBD. In the heart, in vivo CBD treatment protects against ischaemia-reperfusion damage, or against cardiomyopathy associated with diabetes. Similarly, in a different model of ischaemia-reperfusion, CBD has been shown to reduce infarct size and increase blood flow in animal models of stroke, sensitive to 5HT(1A) receptor antagonism. Although acute or chronic CBD treatment seems to have little effect on haemodynamics, CBD reduces the cardiovascular response to models of stress, applied either systemically or intracranially, inhibited by a 5HT(1A) receptor antagonist. In blood, CBD influences the survival and death of white blood cells, white blood cell migration and platelet aggregation. Taken together, this preclinical data appears to support a positive role for CBD treatment in the heart, and in peripheral and cerebral vasculature. However, further work is required to strengthen this hypothesis, establish mechanisms of action and whether similar responses to CBD would be observed in humans. © 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

Cannabis Use Has Negligible Effects Following Severe Traumatic Injury

Article

Mar 2017
J Trauma Nurs

Nearly half of all states have legalized medical marijuana or recreational-use marijuana. As more states move toward legalization, the effects on injured patients must be evaluated. This study sought to determine effects of cannabis positivity at the time of severe injury on hospital outcomes compared with individuals negative for illicit substances and those who were users of other illicit substances. A Level I trauma center performed a retrospective chart review covering subjects over a 2-year period with toxicology performed and an Injury Severity Score (ISS) of more than 16. These individuals were divided into the negative and positive toxicology groups, further divided into the marijuana-only, other drugs-only, and mixed-use groups. Differences in presenting characteristics, hospital length of stay, intensive care unit (ICU) stays, ventilator days, and death were compared. A total of 8,441 subjects presented during the study period; 2,134 (25%) of these had toxicology performed; 843 (40%) had an ISS of more than 16, with 347 having negative tests (NEG); 70 (8.3%) substance users tested positive only for marijuana (MO), 323 (38.3%) for other drugs-only, excluding marijuana (OD), and 103 (12.2%) subjects showed positivity for mixed-use (MU). The ISS was similar for all groups. No differences were identified in Glasgow Coma Scale (GCS), ventilator days, blood administration, or ICU/hospital length of stay when comparing the MO group with the NEG group. Significant differences occurred between the OD group and the NEG/MO/MU groups for GCS, ICU length of stay, and hospital charges. Cannabis users suffering from severe injury demonstrated no detrimental outcomes in this study compared with nondrug users.

From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology

Article

Oct 2016

Apart from having been used and misused for at least four millennia for, among others, recreational and medicinal purposes, the cannabis plant and its most peculiar chemical components, the plant cannabinoids (phytocannabinoids), have the merit to have led humanity to discover one of the most intriguing and pleiotropic endogenous signaling systems, the endocannabinoid system (ECS). This review article aims to describe and critically discuss, in the most comprehensive possible manner, the multifaceted aspects of 1) the pharmacology and potential impact on mammalian physiology of all major phytocannabinoids, and not only of the most famous one Δ(9)-tetrahydrocannabinol, and 2) the adaptive pro-homeostatic physiological, or maladaptive pathological, roles of the ECS in mammalian cells, tissues, and organs. In doing so, we have respected the chronological order of the milestones of the millennial route from medicinal/recreational cannabis to the ECS and beyond, as it is now clear that some of the early steps in this long path, which were originally neglected, are becoming important again. The emerging picture is rather complex, but still supports the belief that more important discoveries on human physiology, and new therapies, might come in the future from new knowledge in this field.

Ultra Low Dose Delta 9-Tetrahydrocannabinol Protects Mouse Liver from Ischemia Reperfusion Injury

Article

Full-text available

Jul 2015

Background/aims: Ischemia/reperfusion (I/R) injury is the main cause of both primary graft dysfunction and primary non-function of liver allografts. Cannabinoids has been reported to attenuate myocardial, cerebral and hepatic I/R oxidative injury. Delta-9-tetrahydrocannabinol (THC), a cannabinoid agonist, is the active components of marijuana. In this study we examined the role of ultralow dose THC (0.002mg/kg) in the protection of livers from I/R injury. This extremely low dose of THC was previously found by us to protect the mice brain and heart from a variety of insults. Methods: C57Bl Mice were studied in in vivo model of hepatic segmental (70%) ischemia for 60min followed by reperfusion for 6 hours. Results: THC administration 2h prior to the induction of hepatic I/R was associated with significant attenuated elevations of: serum liver transaminases ALT and AST, the hepatic oxidative stress (activation of the intracellular signaling CREB pathway), the acute proinflammatory response (TNF-α, IL-1α, IL-10 and c-FOS hepatic mRNA levels, and ERK signaling pathway activation). This was followed by cell death (the cleavage of the pro-apoptotic caspase 3, DNA fragmentation and TUNEL) after 6 hours of reperfusion. Significantly less hepatic injury was detected in the THC treated I/R mice and fewer apoptotic hepatocytes cells were identified by morphological criteria compared with untreated mice. Conclusion: A single ultralow dose THC can reduce the apoptotic, oxidative and inflammatory injury induced by hepatic I/R injury. THC may serve as a potential target for therapeutic intervention in hepatic I/R injury during liver transplantation, liver resection and trauma.

Cannabinoids

Chapter

Jul 2014

Endocannabinoids are endogenous agonists that activate cannabinoid receptors in mammalian tissues. This chapter describes the pharmacological effects and the potential therapeutic applications of cannabinoids in gastrointestinal and liver diseases, with a special emphasis on the experimental and clinical pharmacology of Δ9-tetrahydrocannabinol (THC). Components of the endogenous cannabinoid system have been detected in the gut and in the liver of a number of animal species, including humans. THC, endogenous and synthetic cannabinoids have been evaluated in a number of experimental models of gastrointestinal dysfunctions. Available data suggest that major areas of interest for possible therapeutic application are gastrointestinal reflux disease (GERD), irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and colon cancer. The future direction for the use of cannabinoids in gastrointestinal and liver disorders will have to strike to a balance between unwanted side-effects from CB1 receptor activation and the beneficial actions.

Pharmacologic Effects of Cannabidiol on Acute Reperfused Myocardial Infarction in Rabbits: Evaluated With 3.0T Cardiac Magnetic Resonance Imaging and Histopathology

Article

Full-text available

Jun 2015
J CARDIOVASC PHARM

Cannabidiol (CBD) has anti-inflammatory effects. We explored its therapeutic effects on cardiac ischemia-reperfusion injury with an experimental imaging platform. Reperfused acute myocardial infarction (AMI) was induced in rabbits with a 90-min coronary artery occlusion followed by 24-h reperfusion. Before reperfusion, rabbits received two intravenous doses of 100 μg/kg CBD (n=10) or vehicle (control, n=10). Evans blue was intravenously injected for later detection of the AMI-core. Cardiac magnetic resonance imaging (cMRI) was performed to evaluate cardiac morphology and function. After euthanasia, blood Troponin I (cTnI) was assessed, and the heart was excised and infused with multifunctional red-iodized-oil dye. The heart was sliced for digital radiography to quantify the perfusion density rate (PDR), area at risk (AAR), and myocardial salvage index (MSI), followed by histomorphologic staining. Compared to controls, CBD treatment improved systolic wall thickening (p<0.05), significantly increased blood flow in the AAR (p<0.05), significantly decreased microvascular obstruction (p<0.05), increased the PDR by 1.7-fold, lowered the AMI-core/AAR ratio (p<0.05), and increased the MSI (p<0.05). These improvements were associated with reductions in serum cTnI, cardiac leukocyte infiltration, and myocellular apoptosis (p<0.05). Thus, CBD therapy reduced AMI size and facilitated restoration of LV function. We demonstrated that this experimental platform has potential theragnostic utility.

Nebivolol and chrysin protect the liver against ischemia/reperfusion-induced injury in rats

Article

Mar 2015

Oxidative stress and decrease in nitric oxide play a key role in the pathogenesis of hepatic ischemia/reperfusion (I/R)-induced injury, one of the leading causes of liver damage post-surgical intervention, trauma and transplantation. This study aimed to evaluate the protective effect of nebivolol and chrysin against I/R-induced liver injury via their vasodilator and antioxidant effects, respectively. Adult male Wister rats received nebivolol (5 mg/kg) and/or chrysin (25 mg/kg) by oral gavage daily for one week then subjected to ischemia via clamping the portal triad for 30 min then reperfusion for 30 min. Liver function enzymes, alanine transaminase (ALT) and aspartate transaminase (AST), as well as hepatic Myeloperoxidase (MPO), total nitrate (NOx), glutathione (GSH) and liver malondialdehyde (MDA) were measured at the end of the experiment. Liver tissue damage was examined by histopathology. In addition, the expression levels of nitric oxide synthase (NOS) subtypes, endothelial (eNOS) and inducible (iNOS) in liver samples were assessed by Western blotting and confirmed by immunohistochemical analysis. Both chrysin and nebivolol significantly counteracted I/R-induced oxidative stress and tissue damage biomarkers. The combination of these agents caused additive liver protective effect against I/R-induced damage via the up regulation of nitric oxide expression and the suppression of oxidative stress. Chrysin and nebivolol combination showed a promising protective effect against I/R-induced liver injury, at least in part, via decreasing oxidative stress and increasing nitric oxide levels.

Dioscin Attenuates Hepatic Ischemia-Reperfusion Injury in Rats Through Inhibition of Oxidative-Nitrative Stress, Inflammation and Apoptosis

Article

Jul 2014

Background: Dioscin shows potent effects against liver damage in our previous studies; however, the action of it on hepatic ischemia-reperfusion (I/R) injury is still unknown. In the present article, the effects and possible mechanisms of dioscin against hepatic I/R injury were investigated. Methods: Seventy percent partial hepatic warm ischemia was induced in Wistar rats for 60 min followed by succedent reperfusion. In the prophylactic test, dioscin was administered intragastrically to the rats at doses of 20, 40, and 60 mg/kg once daily for seven consecutive days before I/R. In the therapeutic test, the rats received dioscin intragastrically at a dose of 60 mg/kg once 2 hr before I/R. Results: We found that dioscin significantly decreased serum alanine aminotransferase and aspartate aminotransferase activities, increased survival rate of rats, and improved I/R-induced hepatocyte abnormality. In addition, dioscin obviously increased the levels of SOD, CAT, GSH-Px, GSH, decreased the levels of MDA, TNOS, iNOS, NO, and prevented DNA fragmentation caused by I/R injury. Further research indicated that dioscin markedly decreased the gene expressions of interleukin-1β, interleukin-6, tumor necrosis factor-α, intercellular adhesion molecule-1, MIP-1α, MIP-2, Fas, FasL, decreased the protein expressions of NF-κB, AP-1, COX-2, HMGB-1, CYP2E1, Bak, caspase-3, p53, PARP, Caspase-9, decreased the levels of JNK, ERK and p38 MAPKs phosphorylation, and upregulated the levels of Bcl-2 and Bcl-x. Conclusion: Our results suggest that dioscin has potent actions against hepatic I/R injury through suppression of inflammation, oxidative-nitrative stress, and apoptosis, which should be developed as a new drug to treat hepatic I/R injury in the future.

Protective effect of cannabidiol against cadmium hepatotoxicity in rats

Article

Jul 2013

The protective effect of cannabidiol, the non-psychoactive component of Cannabis sativa, against liver toxicity induced by a single dose of cadmium chloride (6.5mgkg(-1) i.p.) was investigated in rats. Cannabidiol treatment (5mgkg(-1)/day, i.p.) was applied for five days starting three days before cadmium administration. Cannabidiol significantly reduced serum alanine aminotransferase, and suppressed hepatic lipid peroxidation, prevented the depletion of reduced glutathione and nitric oxide, and catalase activity, and attenuated the elevation of cadmium level in the liver tissue resulted from cadmium administration. Histopathological examination showed that cadmium-induced liver tissue injury was ameliorated by cannabidiol treatment. Immunohistochemical analysis revealed that cannabidiol significantly decreased the cadmium-induced expression of tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, caspase-3, and caspase-9, and increased the expression of endothelial nitric oxide synthase in liver tissue. It was concluded that cannabidiol may represent a potential option to protect the liver tissue from the detrimental effects of cadmium toxicity.

Cardioprotective effect of cannabidiol in rats exposed to doxorubicin toxicity

Article

May 2013
ENVIRON TOXICOL PHAR

The potential protective effect of cannabidiol, the major non-psychotropic Cannabis constituent, was investigated against doxorubicin cardiotoxicity in rats. Cardiotoxicity was induced by six equal doses of doxorubicin (2.5mgkg(-1) i.p., each) given at 48h intervals over two weeks to achieve a total dose of 15mgkg(-1). Cannabidiol treatment (5mgkg(-1)/day, i.p.) was started on the same day of doxorubicin administration and continued for four weeks. Cannabidiol significantly reduced the elevations of serum creatine kinase-MB and troponin T, and cardiac malondialdehyde, tumor necrosis factor-α, nitric oxide and calcium ion levels, and attenuated the decreases in cardiac reduced glutathione, selenium and zinc ions. Histopathological examination showed that cannabidiol ameliorated doxorubicin-induced cardiac injury. Immunohistochemical analysis revealed that cannabidiol significantly reduced the expression of inducible nitric oxide synthase, nuclear factor-κB, Fas ligand and caspase-3, and increased the expression of survivin in cardiac tissue of doxorubicin-treated rats. These results indicate that cannabidiol represents a potential protective agent against doxorubicin cardiac injury.

Cannabidiol treatment ameliorates ischemia/reperfusion renal injury in rats

Article

Aug 2012

To investigate the protective effect of cannabidiol, the major non-psychotropic Cannabis constituent, against renal ischemia/reperfusion injury in rats. Bilateral renal ischemia was induced for 30 min followed by reperfusion for 24h. Cannabidiol (5mg/kg, i.v.) was given 1h before and 12h following the procedure. Ischemia/reperfusion caused significant elevations of serum creatinine and renal malondialdehyde and nitric oxide levels, associated with a significant decrease in renal reduced glutathione. Cannabidiol significantly attenuated the deterioration in the measured biochemical parameters induced by ischemia/reperfusion. Histopathological examination showed that cannabidiol ameliorated ischemia/reperfusion-induced kidney damage. Immunohistochemical analysis revealed that cannabidiol significantly reduced the expression of inducible nitric oxide synthase, tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, Fas ligand and caspase-3, and increased the expression of survivin in ischemic/reperfused kidney tissue. Cannabidiol, via its antioxidant and anti-inflammatory properties, may represent a potential therapeutic option to protect against ischemia/reperfusion renal injury.

Impacting tumor cell-fate by targeting the inhibitor of apoptosis protein survivin

Article

Full-text available

Apr 2011
MOL CANCER

Survivin (BIRC5), a member of the inhibitor of apoptosis protein (IAP) family that inhibits caspases and blocks cell death is highly expressed in cancer and is associated with a poorer clinical outcome. Functioning simultaneously during cell division and apoptosis inhibition, survivin plays a pivotal role in determining cell survival. Survivin has consistently been identified by molecular profiling analysis to be associated with higher tumor grade, more advanced disease, abbreviated survival, accelerated rates of recurrence, and chemotherapy and radiation resistance. Survivin's differential expression in cancer compared to normal tissue and its role as a nodal protein in a number of cellular pathways make it a highly flexible therapeutic target, suitable for small-molecule inhibitiors, molecular antagonists, and vaccination-based therapies. By targeting survivin it is hoped that multiple tumor signaling circuitries may be simultaneously disabled. This effect may be applicable to many tumor histologies irrespective of specific genetic makeup. To date, survivin inhibitors have shown modest activity as single agents, but it is anticipated that when given in combination with cytotoxic chemotherapy or monoclonal antibodies they may exhibit enhanced efficacy. This review discusses the complex circuitry of survivin in human cancers and highlights clinical trials involving novel agents that target this important protein.

Cannabidiol reduces lipopolysaccharide-induced vascular changes and inflammation in the mouse brain: An intravital microscopy study

Article

Full-text available

Jan 2011
J NEUROINFLAMM

The phytocannabinoid cannabidiol (CBD) exhibits antioxidant and antiinflammatory properties. The present study was designed to explore its effects in a mouse model of sepsis-related encephalitis by intravenous administration of lipopolysaccharide (LPS). Vascular responses of pial vessels were analyzed by intravital microscopy and inflammatory parameters measured by qRT-PCR. CBD prevented LPS-induced arteriolar and venular vasodilation as well as leukocyte margination. In addition, CBD abolished LPS-induced increases in tumor necrosis factor-alpha and cyclooxygenase-2 expression as measured by quantitative real time PCR. The expression of the inducible-nitric oxide synthase was also reduced by CBD. Finally, preservation of Blood Brain Barrier integrity was also associated to the treatment with CBD. These data highlight the antiinflammatory and vascular-stabilizing effects of CBD in endotoxic shock and suggest a possible beneficial effect of this natural cannabinoid.

Acute administration of cannabidiol in vivo suppresses ischaemia-induced cardiac arrhythmias and reduces infarct size when given at reperfusion

Article

Full-text available

Jul 2010
BRIT J PHARMACOL

Cannabidiol (CBD) is a phytocannabinoid, with anti-apoptotic, anti-inflammatory and antioxidant effects and has recently been shown to exert a tissue sparing effect during chronic myocardial ischaemia and reperfusion (I/R). However, it is not known whether CBD is cardioprotective in the acute phase of I/R injury and the present studies tested this hypothesis. Male Sprague-Dawley rats received either vehicle or CBD (10 or 50 microg kg(-1) i.v.) 10 min before 30 min coronary artery occlusion or CBD (50 microg kg(-1) i.v.) 10 min before reperfusion (2 h). The appearance of ventricular arrhythmias during the ischaemic and immediate post-reperfusion periods were recorded and the hearts excised for infarct size determination and assessment of mast cell degranulation. Arterial blood was withdrawn at the end of the reperfusion period to assess platelet aggregation in response to collagen. CBD reduced both the total number of ischaemia-induced arrhythmias and infarct size when administered prior to ischaemia, an effect that was dose-dependent. Infarct size was also reduced when CBD was given prior to reperfusion. CBD (50 microg kg(-1) i.v.) given prior to ischaemia, but not at reperfusion, attenuated collagen-induced platelet aggregation compared with control, but had no effect on ischaemia-induced mast cell degranulation. This study demonstrates that CBD is cardioprotective in the acute phase of I/R by both reducing ventricular arrhythmias and attenuating infarct size. The anti-arrhythmic effect, but not the tissue sparing effect, may be mediated through an inhibitory effect on platelet activation.

Non-CB1, Non-CB2 Receptors for Endocannabinoids, Plant Cannabinoids, and Synthetic Cannabimimetics: Focus on G-protein-coupled Receptors and Transient Receptor Potential Channels

Article

Full-text available

Oct 2009
J NEUROIMMUNE PHARM

The molecular mechanism of action of Delta(9)-tetrahydrocannabinol (THC), the psychotropic constituent of Cannabis, has been a puzzle during the three decades separating its characterization, in 1964, and the cloning, in the 1990s, of cannabinoid CB1 and CB2 receptors. However, while these latter proteins do mediate most of the pharmacological actions of THC, they do not seem to act as receptors for other plant cannabinoids (phytocannabinoids), nor are they the unique targets of the endogenous lipids that were originally identified in animals as agonists of CB1 and CB2 receptors, and named endocannabinoids. Over the last decade, several potential alternative receptors for phytocannabinoids, endocannabinoids, and even synthetic cannabimimetics, have been proposed, often based uniquely on pharmacological evidence obtained in vitro. In particular, the endocannabinoid anandamide, and the other most abundant Cannabis constituent, cannabidiol, seem to be the most "promiscuous" of these compounds. In this article, we review the latest data on the non-CB1, non-CB2 receptors suggested so far for endocannabinoids and plant or synthetic cannabinoids, and lay special emphasis on uncharacterized or orphan G-protein-coupled receptors as well as on transient receptor potential channels.

Cannabidiol, a safe and non-psychotropic ingredient of the marijuana plant Cannabis sativa, is protective in a murine model of colitis

Article

Full-text available

Sep 2009
J MOL MED-JMM

Inflammatory bowel disease affects millions of individuals; nevertheless, pharmacological treatment is disappointingly unsatisfactory. Cannabidiol, a safe and non-psychotropic ingredient of marijuana, exerts pharmacological effects (e.g., antioxidant) and mechanisms (e.g., inhibition of endocannabinoids enzymatic degradation) potentially beneficial for the inflamed gut. Thus, we investigated the effect of cannabidiol in a murine model of colitis. Colitis was induced in mice by intracolonic administration of dinitrobenzene sulfonic acid. Inflammation was assessed both macroscopically and histologically. In the inflamed colon, cyclooxygenase-2 and inducible nitric oxide synthase (iNOS) were evaluated by Western blot, interleukin-1beta and interleukin-10 by ELISA, and endocannabinoids by isotope dilution liquid chromatography-mass spectrometry. Human colon adenocarcinoma (Caco-2) cells were used to evaluate the effect of cannabidiol on oxidative stress. Cannabidiol reduced colon injury, inducible iNOS (but not cyclooxygenase-2) expression, and interleukin-1beta, interleukin-10, and endocannabinoid changes associated with 2,4,6-dinitrobenzene sulfonic acid administration. In Caco-2 cells, cannabidiol reduced reactive oxygen species production and lipid peroxidation. In conclusion, cannabidiol, a likely safe compound, prevents experimental colitis in mice.

Cannabidiol: A Promising Drug for Neurodegenerative Disorders?

Article

Full-text available

Feb 2009
CNS NEUROSCI THER

Neurodegenerative diseases represent, nowadays, one of the main causes of death in the industrialized country. They are characterized by a loss of neurons in particular regions of the nervous system. It is believed that this nerve cell loss underlies the subsequent decline in cognitive and motor function that patients experience in these diseases. A range of mutant genes and environmental toxins have been implicated in the cause of neurodegenerative disorders but the mechanism remains largely unknown. At present, inflammation, a common denominator among the diverse list of neurodegenerative diseases, has been implicated as a critical mechanism that is responsible for the progressive nature of neurodegeneration. Since, at present, there are few therapies for the wide range of neurodegenerative diseases, scientists are still in search of new therapeutic approaches to the problem. An early contribution of neuroprotective and antiinflammatory strategies for these disorders seems particularly desirable because isolated treatments cannot be effective. In this contest, marijuana derivatives have attracted special interest, although these compounds have always raised several practical and ethical problems for their potential abuse. Nevertheless, among Cannabis compounds, cannabidiol (CBD), which lacks any unwanted psychotropic effect, may represent a very promising agent with the highest prospect for therapeutic use.

New Insights into the Regulation of Inducible Nitric-Oxide Synthesis

Article

Full-text available

Jul 1994
Am J Physiol

Recent studies have identified the induction of nitric oxide (NO) synthesis in many cell types as part of the host response to sepsis and inflammation. Induced NO can have a variety of effects which may be detrimental or beneficial during sepsis or inflammation, depending on amount, duration, and anatomic site of synthesis. As arginine is the only physiological nitrogen donor for NO synthesis, metabolism of this amino acid may play an important role in regulation of NO synthesis during sepsis. This review will discuss the roles NO plays in sepsis and the potential impact of arginine metabolism on NO synthesis.

Preliminary assessment of the efficacy, tolerability and safety of a cannabis-based medicine (Sativex) in the treatment of pain caused by rheumatoid arthritis

Article

Full-text available

Feb 2006

To assess the efficacy of a cannabis-based medicine (CBM) in the treatment of pain due to rheumatoid arthritis (RA). We compared a CBM (Sativex) with placebo in a randomized, double-blind, parallel group study in 58 patients over 5 weeks of treatment. The CBM was administered by oromucosal spray in the evening and assessments were made the following morning. Efficacy outcomes assessed were pain on movement, pain at rest, morning stiffness and sleep quality measured by a numerical rating scale, the Short-Form McGill Pain Questionnaire (SF-MPQ) and the DAS28 measure of disease activity. Seventy-five patients were screened and 58 met the eligibility criteria. Thirty-one were randomized to the CBM and 27 to placebo. Mean (S.D.) daily dose achieved in the final treatment week was 5.4 (0.84) actuations for the CBM and 5.3 (1.18) for placebo. In comparison with placebo, the CBM produced statistically significant improvements in pain on movement, pain at rest, quality of sleep, DAS28 and the SF-MPQ pain at present component. There was no effect on morning stiffness but baseline scores were low. The large majority of adverse effects were mild or moderate, and there were no adverse effect-related withdrawals or serious adverse effects in the active treatment group. In the first ever controlled trial of a CBM in RA, a significant analgesic effect was observed and disease activity was significantly suppressed following Sativex treatment. Whilst the differences are small and variable across the population, they represent benefits of clinical relevance and show the need for more detailed investigation in this indication.

Carrier EJ, Auchampach JA, Hillard CJ. Inhibition of an equilibrative nucleoside transporter by cannabidiol: a mechanism of cannabinoid immunosuppression. Proc Natl Acad Sci USA 103: 7895-7900

Article

Full-text available

May 2006

The plant-derived cannabinoids delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD) both have immunosuppressive effects; although some effects of THC are mediated by the CB2 receptor, CB2 binds CBD weakly. In examining the effects of THC and CBD on microglial proliferation, we found that these compounds potently inhibit [3H]thymidine incorporation into a murine microglial cell line with no effect on cell cycle. Treatment with THC and CBD decreased [3H]thymidine uptake into microglia, with IC50 values that match inhibition of [3H]thymidine incorporation into DNA. CBD and, less potently, THC decreased uptake of [3H]adenosine to a similar extent as [3H]thymidine in both murine microglia and RAW264.7 macrophages. Binding studies confirm that CBD binds to the equilibrative nucleoside transporter 1 with a Ki < 250 nM. Because adenosine agonists have antiinflammatory effects, and because uptake of adenosine is a primary mechanism of terminating adenosine signaling, we tested the hypothesis that CBD is immunosuppressive because it enhances endogenous adenosine signaling. In vivo treatment with a low dose of CBD decreases TNFalpha production in lipopolysaccharide-treated mice; this effect is reversed with an A2A adenosine receptor antagonist and abolished in A2A receptor knockout mice. These studies demonstrate that CBD has the ability to enhance adenosine signaling through inhibition of uptake and provide a non-cannabinoid receptor mechanism by which CBD can decrease inflammation.

Survivin is not only a death encounter but also a survival protein for invading tumor cells

Article

Full-text available

Feb 2007
FRONT BIOSCI

Cell proliferation and cell death pathways meet at a pivotal crossroad, crucial to maintain normal homeostasis and to eliminate dangerous cells before they start dividing. Survivin (SVV) is an intriguing and fascinating protein at this crossroad that interfaces life and death, through its dual role in facilitating cell division and encountering apoptosis. SVV's prominent expression in essentially all human malignancies, and low or no expression in most normal tissues, suggests that it would be an ideal target for cancer-directed therapy. However, SVV has been recently described as a target for fine tuning by alternative splicing mechanism generating five defined splice variants and a number of other uncharacterized/bizarre isoforms. This diversity indicates that SVV, in addition to its known functions in tumorgenesis, angiogenesis and cardiovascular diseases, might be associated with other unknown functions. Intriguingly, new accumulating evidence from our own work and others, suggest a novel role for SVV in the mechanisms of tumor invasion and metastasis. The SVV pathway has now provided tangible opportunities for targeted, rational cancer therapy. It is therefore an attractive and promising therapeutic target not only for cancer but also for other diseases. Although a number of studies utilizing SVV as an anti-cancer strategy are well underway, further investigation into the exact molecular interactions underpinning its functions is critical for the success of such trials. Impeding development of safe and effective SVV antagonists for clinical use is due to a lack of understanding the molecular mechanisms by which SVV differentially affects apoptosis and cell division in both normal and malignant cells. In this report, in addition to reviewing the SVV known functions, we discuss the newly proposed mechanisms by which SVV might serve as a survival tool for invading tumor cells.

Cannabidiol, a nonpsychoactive Cannabis constituent, protects against myocardial ischemic reperfusion injury

Article

Full-text available

Dec 2007

Cannabidiol (CBD) is a major, nonpsychoactive Cannabis constituent with anti-inflammatory activity mediated by enhancing adenosine signaling. Inasmuch as adenosine receptors are promising pharmaceutical targets for ischemic heart diseases, we tested the effect of CBD on ischemic rat hearts. For the in vivo studies, the left anterior descending coronary artery was transiently ligated for 30 min, and the rats were treated for 7 days with CBD (5 mg/kg ip) or vehicle. Cardiac function was studied by echocardiography. Infarcts were examined morphometrically and histologically. For ex vivo evaluation, CBD was administered 24 and 1 h before the animals were killed, and hearts were harvested for physiological measurements. In vivo studies showed preservation of shortening fraction in CBD-treated animals: from 48 +/- 8 to 39 +/- 8% and from 44 +/- 5 to 32 +/- 9% in CBD-treated and control rats, respectively (n = 14, P < 0.05). Infarct size was reduced by 66% in CBD-treated animals, despite nearly identical areas at risk (9.6 +/- 3.9 and 28.2 +/- 7.0% in CBD and controls, respectively, P < 0.001) and granulation tissue proportion as assessed qualitatively. Infarcts in CBD-treated animals were associated with reduced myocardial inflammation and reduced IL-6 levels (254 +/- 22 and 2,812 +/- 500 pg/ml in CBD and control rats, respectively, P < 0.01). In isolated hearts, no significant difference in infarct size, left ventricular developed pressures during ischemia and reperfusion, or coronary flow could be detected between CBD-treated and control hearts. Our study shows that CBD induces a substantial in vivo cardioprotective effect from ischemia that is not observed ex vivo. Inasmuch as CBD has previously been administered to humans without causing side effects, it may represent a promising novel treatment for myocardial ischemia.

Protective effects of apocynin and allopurinol on ischemia/reperfusion-induced liver injury in mice

Article

Full-text available

Jun 2008
WORLD J GASTROENTERO

To determine the effects of allopurinol, an inhibitor of xanthine oxidase, and apocynin, an inhibitor of NADPH oxidase, on oxidant stress and liver injury caused by hepatic ischemia/reperfusion (I/R) procedure in mice. Mice were pretreated with a xanthine oxidase inhibitor, allopurinol, or NADPH oxidase (NOX) inhibitor, apocynin before the hepatic I/R procedure. Then treated or untreated mice underwent the hepatic I/R procedure. The effects on hepatic injury and superoxide anions were determined after starting reperfusion. A standard warm hepatic I/R procedure led to a marked increase in superoxide anion production as indicated by a superoxide anion tracer, MCLA. At the same time, the procedure caused profound acute liver injury, as indicated by elevated serum alanine aminotransferase and tumor necrosis factor-alpha levels, reduced liver glutathione levels and elevated malondialdehyde contents, as well as a high apoptotic cell count. All these changes were reversed by the use of apocynin or allopurinol prior to the hepatic I/R procedure. Allopurinol and apocynin exerted protective effects on hepatic ischemia/reperfusion injury. The protection is associated with blocking the generation of superoxide anions during the hepatic I/R procedure by inhibiting xanthine oxidase and NADPH oxidase activity.

Conversion of xanthine dehydrogenase into xanthine oxidase in rat liver and plasma at the onset of reperfusion after ischemia

Article

Jun 1994

A Kooij

Molecular targets for cannabidiol and its synthetic analogues: Effect on vanilloid VR1 receptors and on the cellular uptake and enzymatic hydrolysis of anandamide

Article

Oct 2001
BRIT J PHARMACOL

(−)-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

Cannabidiol protects against hepatic ischemia/reperfusion injury by attenuating inflammatory signaling and response, oxidative/nitrative stress, and cell death

Article

Feb 2011

Ischemia/reperfusion (I/R) is a pivotal mechanism of liver damage after liver transplantation or hepatic surgery. We have investigated the effects of cannabidiol (CBD), the nonpsychotropic constituent of marijuana, in a mouse model of hepatic I/R injury. I/R triggered time-dependent increases/changes in markers of liver injury (serum transaminases), hepatic oxidative/nitrative stress (4-hydroxy-2-nonenal, nitrotyrosine content/staining, and gp91phox and inducible nitric oxide synthase mRNA), mitochondrial dysfunction (decreased complex I activity), inflammation (tumor necrosis factor α (TNF-α), cyclooxygenase 2, macrophage inflammatory protein-1α/2, intercellular adhesion molecule 1 mRNA levels; tissue neutrophil infiltration; nuclear factor κB (NF-κB) activation), stress signaling (p38MAPK and JNK), and cell death (DNA fragmentation, PARP activity, and TUNEL). CBD significantly reduced the extent of liver inflammation, oxidative/nitrative stress, and cell death and also attenuated the bacterial endotoxin-triggered NF-κB activation and TNF-α production in isolated Kupffer cells, likewise the adhesion molecule expression in primary human liver sinusoidal endothelial cells stimulated with TNF-α and attachment of human neutrophils to the activated endothelium. These protective effects were preserved in CB2 knockout mice and were not prevented by CB1/2 antagonists in vitro. Thus, CBD may represent a novel, protective strategy against I/R injury by attenuating key inflammatory pathways and oxidative/nitrative tissue injury, independent of classical CB1/2 receptors.

Cannabidiol Attenuates Cardiac Dysfunction, Oxidative Stress, Fibrosis, and Inflammatory and Cell Death Signaling Pathways in Diabetic Cardiomyopathy

Article

Dec 2010

In this study, we have investigated the effects of cannabidiol (CBD) on myocardial dysfunction, inflammation, oxidative/nitrative stress, cell death, and interrelated signaling pathways, using a mouse model of type I diabetic cardiomyopathy and primary human cardiomyocytes exposed to high glucose. Cannabidiol, the most abundant nonpsychoactive constituent of Cannabis sativa (marijuana) plant, exerts anti-inflammatory effects in various disease models and alleviates pain and spasticity associated with multiple sclerosis in humans. Left ventricular function was measured by the pressure-volume system. Oxidative stress, cell death, and fibrosis markers were evaluated by molecular biology/biochemical techniques, electron spin resonance spectroscopy, and flow cytometry. Diabetic cardiomyopathy was characterized by declined diastolic and systolic myocardial performance associated with increased oxidative-nitrative stress, nuclear factor-κB and mitogen-activated protein kinase (c-Jun N-terminal kinase, p-38, p38α) activation, enhanced expression of adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1), tumor necrosis factor-α, markers of fibrosis (transforming growth factor-β, connective tissue growth factor, fibronectin, collagen-1, matrix metalloproteinase-2 and -9), enhanced cell death (caspase 3/7 and poly[adenosine diphosphate-ribose] polymerase activity, chromatin fragmentation, and terminal deoxynucleotidyl transferase dUTP nick end labeling), and diminished Akt phosphorylation. Remarkably, CBD attenuated myocardial dysfunction, cardiac fibrosis, oxidative/nitrative stress, inflammation, cell death, and interrelated signaling pathways. Furthermore, CBD also attenuated the high glucose-induced increased reactive oxygen species generation, nuclear factor-κB activation, and cell death in primary human cardiomyocytes. Collectively, these results coupled with the excellent safety and tolerability profile of CBD in humans, strongly suggest that it may have great therapeutic potential in the treatment of diabetic complications, and perhaps other cardiovascular disorders, by attenuating oxidative/nitrative stress, inflammation, cell death and fibrosis.

Protective Effects of Baicalin against Ischemia/Reperfusion Injury in Rat Liver

Article

Nov 2010
J NAT PROD

The cytoprotective properties of baicalin (1), a flavonoid glycoside isolated from Scutellaria baicalensis, have been investigated against injury to the liver caused by ischemia/reperfusion (I/R). Rats were subjected to 60 min of ischemia followed by 5 h of reperfusion, and 1 was administered intraperitoneally 24 and 1 h before ischemia. Following I/R, the levels of serum alanine aminotransferase and hepatic lipid peroxidation were elevated, whereas the hepatic glutathione content was decreased, with these changes attenuated by 1. Serum levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were markedly increased by I/R, but suppressed by 1. Baicalin attenuated increases in inducible nitric oxide synthase, cyclooxygenase (COX)-2, and TNF receptor 1-associated protein expression and augmented an increase in heme oxygenase-1 (HO-1). The increase in TNF-α, IL-6, and, COX-2 mRNA expression was attenuated by 1, while the increase in HO-1 mRNA expression was augmented. Nuclear factor-κB nuclear localization was inhibited by 1, and this compound limited the rate of mitochondrial swelling and the activation of caspases-3 and -8 observed in I/R rats. Rats treated with 1 had markedly fewer apoptotic cells than I/R rats. It was concluded that baicalin (1) exhibits antioxidant, anti-inflammatory, and antiapoptotic effects, which protect against hepatocellular I/R-induced damage.

Protective Role of Heme Oxygenase-1 Against Liver Damage Caused by Hepatic Ischemia and Reperfusion in Rats

Article

May 2010
ANTIOXID REDOX SIGN

This study investigated the time course of heme oxygenase (HO)-1 expression and the role of endogenous HO-1 in hepatic ischemia and reperfusion (I/R). Rats were pretreated with hemin, an HO-1 inducer, and zinc protoporphyrin (ZnPP), an HO-1 inhibitor. Hepatic HO activity increased at 1 h after reperfusion, reaching a maximum at 6 h after reperfusion and then declined. HO-1 mRNA and protein expression in I/R liver were upregulated prior to reperfusion and highly induced again by reperfusion. The ALT level was upregulated at all time points, with a peak at 4-6 h. This increase was augmented by ZnPP but attenuated by hemin. Lipid peroxidation and serum HMGB1 release significantly increased at 1 h after reperfusion and remained elevated throughout the 24 h of reperfusion period, whereas the glutathione content decreased markedly at 4-6 h after reperfusion. These changes were attenuated by hemin but augmented by ZnPP. The levels of serum TNF-α, iNOS, and COX-2 protein and mRNA expressions were upregulated after reperfusion, further enhanced by ZnPP, and suppressed by hemin. HO-1 overexpression protects the liver against I/R injury by modulating oxidative stress and proinflammatory mediators.

Protective effect of methylprednisolone on warm ischemia-reperfusion injury in a cholestatic rat liver

Article

Mar 2010

Cholestasis has been identified as a risk factor for oxidative stress, and it potentially enhances after ischemic-reperfusion injury. The aim of this study was to evaluate the role of methylprednisolone on warm ischemia-reperfusion injury in the presence of cholestasis. A reversible cholestatic rat model was created. After 7 days, rats received 30 mg/kg of intravenous methylprednisolone 2 hours before ischemia, followed by 30 minutes of ischemia. Rats were euthanized 24 hours after ischemia. Serum aspartate aminotransferase and interleukin-6 were measured, and the liver was harvested for histology and myeloperoxidase estimation. Methylprednisolone had a protective effect, with a statistically significant decrease in aspartate aminotransferase (P=.01) and a trend toward decreased levels of interleukin-6 (P=.07). Histology showed a significant difference in architectural distortion (P=.01), cytoplasmic vacuolation (P=.01), and nodular hepatocellular necrosis (P=.04). Methylprednisolone attenuated the ischemic-reperfusion injury in the presence of cholestasis and can be considered for clinical use in the presence of cholestasis.

Cytochrome P450 induction by phenobarbital exacerbates warm hepatic ischemia-reperfusion injury in rat livers

Article

Feb 2010
FREE RADICAL RES

Recent studies have shown that cytochrome P450 inhibitors reduce oxidative stress and injury to the liver following warm ischemia-reperfusion (IR). The aim here was to test the effect of P450 induction by phenobarbital on the IR injury in rat livers. Rats were pre-treated with saline or phenobarbital and subjected to IR or sham operation. IR significantly increased the plasma alanine aminotransferase concentrations. Phenobarbital further exacerbated the injury by an additional 50% increase in the alanine aminotransferase levels. Phenobarbital also caused an approximately 40% increase in the total P450 content of the liver, which was also associated with a 75% increase in the reactive oxygen species (ROS) generation in the IR group. There was a strong correlation between the microsomal ROS generation and total P450 content, CYP3A2 activity or CYP2B1 activity. It is concluded that the induction of P450 by phenobarbital significantly increases hepatic production of ROS, leading to significantly higher hepatic IR injury.

Effects of the Antioxidants Lycium Barbarum and Ascorbic Acid on Reperfusion Liver Injury in Rats

Article

Dec 2009

Ischemia/reperfusion (I/R) of the rat liver can induce liver injury through mechanisms involving oxidative and nitrosative stresses. In this study we examined the effects of antioxidants Lycium barbarum (LB) and ascorbic acid on I/R-induced liver injury in rats. Liver ischemia was induced by clamping the common hepatic artery and portal vein of rats for 40 minutes. Thereafter, flow was restored with reperfusion for 90 minutes. Blood samples collected before ischemia and after reperfusion were analyzed for alanine transaminase (ALT), lactic dehydrogenase (LDH), hydroxyl radical, and nitric oxide (NO) levels. Pharmacologic interventions included administration of ascorbic acid (100 mg/kg, i.p., 1 hour before I/R) or LB, an extract of Gogi berries: 600 mg in 100 mL of drinking water for 2 weeks prior to experimentation. This protocol resulted in elevation of blood concentrations of NO, hydroxyl radical, ALT, and LDH (P < .001) in the I/R-induced liver injury group. Ascorbic acid significantly attenuated the reperfusion liver injury by attenuating hydroxyl radical (P < .01) and NO (P < .05) release. The LB aggravated I/R-induced liver injury by increasing hydroxyl radical release with no effect on NO release. This I/R protocol resulted in oxidative and nitrosative stress and liver injury. Ascorbic acid showed significant protective effects on reperfusion liver injury by attenuating hydroxyl radical and NO release. In contrast, LB aggravated liver injury by increasing hydroxyl radical release.

Role of Hydrogen Sulfide in Hepatic Ischemia-Reperfusion-Induced Injury In Rats

Article

Oct 2009
LIVER TRANSPLANT

Hydrogen sulfide (H2S) displays anti-inflammatory and cytoprotective activities as evidenced by the inhibition of myocardial ischemia-reperfusion injury and production of lipid peroxidation. H2S also exerts many physiological or pathological effects on livers. Therefore, we designed the present study to investigate the roles of H2S in hepatic ischemia-reperfusion (HIR)-induced injury in rats by measuring H2S levels, H2S synthesizing activity, and cystathionine gamma-lyase (CSE) messenger RNA (mRNA) expression. We also applied DL-propargyl glycine (PAG) and sodium hydrosulfide (NaHS) to investigate their effects on the severity of liver injury induced by HIR. The levels of H2S, H2S production activity, and CSE mRNA expression in livers were increased by HIR. Administration of NaHS significantly attenuated the severity of liver injury and inhibited the production of lipid peroxidation, serum inflammatory factors [including nitric oxide, tumor necrosis factor alpha (TNF-alpha), interleukin 10, and intercellular cell adhesion molecule 1], cell apoptosis, and apoptosis-related proteins (including caspase-3, Fas, Fas ligand, and TNF-alpha), which were caused or elevated by HIR, whereas PAG aggravated them. However, NaHS or PAG did not show significant effects on the activation of caspase-9, which was also increased by HIR. Although further investigation is required, this study may indicate that H2S plays a protective role in HIR-induced injury.

Effect of olprinone, a phosphodiesterase III inhibitor, on hepatic ischemia-reperfusion injury in rats

Article

Sep 2009
SHOCK

I/R injury is the main cause for hepatic dysfunction and failure after liver transplantation and liver resection. Therefore, reduction of I/R injury is the most important goal to improve the outcome of these procedures. Olprinone is a newly developed selective phosphodiesterase III inhibitor, which has been reported to ameliorate renal I/R injury in rats. However, no clear evidence for the actions of olprinone on inflammatory response after hepatic I/R injury has been disclosed thus far. Our study was designed to evaluate the action of olprinone on the hepatic I/R injury in rats. Olprinone increased the cyclic adenosine monophosphate level in injured liver tissue and ameliorated the liver injury after hepatic I/R. Moreover, olprinone suppressed the activation of p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and nuclear factor-kappaB, cytokine production (TNF-alpha, IL-6, and cytokine-induced neutrophil chemoattractant factor 1), and intercellular adhesion molecule 1 expression in liver after hepatic I/R. These observations suggest that olprinone protects liver against I/R injury via the elevation of cyclic adenosine monophosphate level and suppression of intercellular adhesion molecule 1 expression and cytokine production (TNF-alpha, IL-6, and cytokine-induced neutrophil chemoattractant factor 1), possibly by interfering with the signaling pathways of p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and nuclear factor-kappaB in rats.

Therapeutic Time Window of Cannabidiol Treatment on Delayed Ischemic Damage via High-Mobility Group Box1-Inhibiting Mechanism

Article

Oct 2009
BIOL PHARM BULL

Cannabidiol decreases cerebral infarction and high-mobility group box1 (HMGB1) in plasma in ischemic early phase. However, plasma HMGB1 levels in ischemic delayed phase reach higher concentration with the progressing brain injury. In this study, we investigated the therapeutic time window of cannabidiol on functional deficits, glial HMGB1 and plasma HMGB1 levels in a 4 h mouse middle cerebral artery (MCA) occlusion model. Cannabidiol-treated mice were divided into 3 groups as follows: group (a) treated from day 1, group (b) treated from day 3, group (c) treated from day 5 after MCA occlusion. Moreover, minocycline, microglia inhibitor, and fluorocitrate, an inhibitor of astroglial metabolism, were used to compare with cannabidiol-treated group. Repeated treatment with cannabidiol from 1 and 3 d at the latest after cerebral ischemia improved functional deficits and survival rates. However, cannabidiol from 5 d could not improve the ischemic damage as well as fluorocitrate-treated group. Moreover, both group (a), group (b) and minocycline but not group (c) and fluorocitrate-treated group had a decrease in the number of Iba1 expressing HMGB1 positive cells and HMGB1 levels in plasma. Cannabidiol may provide therapeutic possibilities for the progressing brain injury via HMGB1-inhibiting mechanism.

Induction of hepatic cyclooxygenase-2 by hyperhomocysteinemia via nuclear factor- B activation

Article

Sep 2009
AM J PHYSIOL-REG I

Hyperhomocysteinemia, an elevation of blood homocysteine (Hcy), is a metabolic disorder associated with dysfunction of multiple organs. Apart from endothelial dysfunction, Hcy can cause hepatic lipid accumulation and liver injury. However, the mechanism responsible for Hcy-induced liver injury is poorly understood. The aim of this study was to investigate the regulation of cyclooxygenase-2 (COX-2), a proinflammatory factor, expression in the liver during the initial phase of hyperhomocysteinemia. Sprague-Dawley rats were fed a high-methionine diet for 1 or 4 wk. Serum and liver concentrations of Hcy were significantly elevated after 1 or 4 wk of dietary treatment. COX-2 mRNA and protein levels were significantly elevated in the liver of hyperhomocysteinemic rats. The induction of COX-2 expression was more prominent in 1-wk hyperhomocysteinemic rats than that in the 4-wk group. EMSA revealed an activation of NF-kappaB in the same liver tissue in which COX-2 was induced. Administration of a NF-kappaB inhibitor to hyperhomocysteinemic rats effectively abolished hepatic COX-2 expression, inhibited the formation of inflammatory foci, and improved liver function. Further investigation revealed that oxidative stress due to increased superoxide generation was responsible for increased phosphorylation and degradation of IkappaBalpha leading to NF-kappaB activation in the liver. Administration of 4-hydroxy-tetramethyl-piperidine-1-oxyl, an SOD mimetic, to hyperhomocysteinemic rats not only inhibited NF-kappaB activation but also prevented hepatic COX-2 induction and improved liver function. These results suggest that hyperhomocysteinemia-induced COX-2 expression is mediated via NF-kappaB activation. Increased oxidative stress and inflammatory response may contribute to liver injury associated with hyperhomocysteinemia.

Ryan BM, O'Donovan N, Duffy MJ.. Survivin: a new target for anti-cancer therapy. Cancer Treat Rev 35: 553-562

Article

Jul 2009

Survivin is one of the most cancer-specific proteins identified to date, being upregulated in almost all human tumors. Biologically, survivin has been shown to inhibit apoptosis, enhance proliferation and promote angiogenesis. Because of its upregulation in malignancy and its key role in apoptosis, proliferation and angiogenesis, survivin is currently attracting considerable attention as a new target for anti-cancer therapies. In several animal model systems, downregulation of survivin or inactivation of its function has been shown to inhibit tumor growth. Strategies under investigation to target survivin include antisense oligonucleotides, siRNA, ribozymes, immunotherapy and small molecular weight molecules. The translation of these findings to the clinic is currently ongoing with a number of phase I/II clinical trials targeting survivin in progress. These include use of the antisense oligonucleotide LY2181308, the low molecular weight molecule inhibitor YM155 and survivin-directed autologous cytotoxic T lymphocytes. The optimum use of survivin antagonists in the treatment of cancer is likely to be in combination with conventional cancer therapies.

Protective effect of bicyclol on liver injury induced by hepatic warm ischemia/reperfusion in rats

Article

Apr 2009

Aim: Bicyclol is a synthetic anti-hepatitis drug with anti-oxidative property. The purpose of this study was to investigate the effect of bicyclol on hepatic ischemia/reperfusion (I/R) injury and related mechanisms. Methods: Rats were subjected to 90 min of hepatic ischemia followed by reperfusion for 1, 3, 6 and 24 h. Three doses of bicyclol were orally administered before ischemia. Liver injury was evaluated by biochemical and histopathological examinations. Liver malondialdehyde (MDA), superoxide dismutase (SOD), nitric oxide (NO), inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) contents, and plasma endotoxin levels were spectrophotometrically measured. The expressions of inflammatory and anti-inflammatory cytokines were detected by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Liver intercellular adhesion molecule-1 (ICAM-1) was examined by immunohistochemistry, and the expressions of nuclear factor (NF)-κB, inhibitor of NF-κB (IκB) and toll-like receptor 4 (TLR4) were determined by western blot. Results: Bicyclol significantly inhibited the elevations of serum alanine aminotransferase, total bilirubin and plasma endotoxin levels, alleviated the formation of liver MDA and nitrite/nitrate, restored impaired antioxidant SOD, attenuated hepatic necrosis and neutrophil infiltration, and also improved the 7-day survival in I/R rats. Additionally, bicyclol markedly downregulated the overexpression of ICAM-1, modulated the expression of inflammatory/anti-inflammatory cytokines and inhibited the expression of NF-κB and TLR4 in I/R rats. Conclusion: Bicyclol had a remarkable protective effect on hepatic I/R injury, which was partially due to inhibiting the expression of TLR4 and NF-κB via its ability to attenuate oxidative stress and endotoxin.

Protective effects of taurine against endotoxin-induced acute liver injury after hepatic ischemia reperfusion

Article

Apr 2009
AMINO ACIDS

Hepatic ischemia reperfusion (HIR) not only results in liver injury, but also leads to endotoxemia, which aggravates HIR-induced liver injury and dysfunction, or even causes liver failure. Taurine has been shown to protect organs from ischemia reperfusion or endotoxin by its anti-oxidant and anti-inflammatory activities. The aim of this study was to investigate whether taurine could attenuate endotoxin-induced acute liver injury after HIR. Wistar rats subjected to 30 min of hepatic ischemia followed by reperfusion and lipopolysaccharide (LPS) (0.5 mg/kg) administration, exhibited liver dysfunction (elevated serum levels of ALT, AST and LDH) and hepatic histopathological alteration. The serum levels of TNF-alpha and production of myeloperoxidase (MPO) and malondialdehyde (MDA) in liver tissues and apoptosis of hepatocytes were also increased after the combination of HIR and LPS. However, pre-administration of taurine protected livers from injury induced by the combination of HIR + LPS as the histological score, apoptotic index, MPO activity and production of MDA in liver tissues, and serum levels of AST, ALT, LDH and TNF-alpha, were significantly reduced. The expression of caspase-3, Fas and Fas ligand was upregulated in homogenates of livers from rats subjected to HIR and LPS, and this elevated expression could be inhibited by taurine. In summary, the results further emphasize the potential utilization of taurine in protecting livers against endotoxin-induced injury especially after HIR, by its anti-inflammatory, anti-oxidative and anti-apoptotic activities.

Cannabidiol Attenuates Cisplatin-Induced Nephrotoxicity by Decreasing Oxidative/Nitrosative Stress, Inflammation, and Cell Death

Article

Mar 2009
J PHARMACOL EXP THER

The platinum compound cisplatin is one of the most potent chemotherapy agents available to treat various malignancies. Nephrotoxicity is a common complication of cisplatin chemotherapy, which involves increased oxidative and nitrosative stress, limiting its clinical use. In this study, we have investigated the effects of a nonpsychoactive cannabinoid cannabidiol, which was reported to exert antioxidant effects and has recently been approved for the treatment of inflammation, pain, and spasticity associated with multiple sclerosis in patients in a mouse model of cisplatin-induced nephropathy. Cisplatin induced increased expression of superoxide-generating enzymes RENOX (NOX4) and NOX1, enhanced reactive oxygen species generation, inducible nitric-oxide synthase expression, nitrotyrosine formation, apoptosis (caspase-3/7 activity, DNA fragmentation, and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining), poly(ADP-ribose) polymerase activity, and inflammation (tumor necrosis factor-alpha and interleukin-1beta) in the kidneys of mice, associated with marked histopathological damage and impaired renal function (elevated serum blood urea nitrogen and creatinine levels) 72 h after the administration of the drug. Treatment of mice with cannabidiol markedly attenuated the cisplatin-induced oxidative/nitrosative stress, inflammation, and cell death in the kidney, and it improved renal function. Thus, our results suggest that cannabidiol may represent a promising new protective strategy against cisplatin-induced nephrotoxicity.

Protective effect of ischemic preconditioning on hepatic ischemia-reperfusion injury by advancing the expressive phase of survivin in rats

Article

Dec 2008
HEPATOB PANCREAT DIS

Survivin is a new and important gene in the regulation of apoptosis. It is very important to explore the effect of the expression of survivin protein caused by ischemia-reperfusion (IR) injury. The effect of IR injury caused by ischemic preconditioning (IP) on the liver in rats and the relation between the protective effect of IP and the expression of survivin are unclear. One hundred and fifty male Wistar rats (weighing 190-210 g, aged 6-7 weeks) were divided into three groups at random: ischemic preconditioning (IP), ischemia-reperfusion (IR) and sham-operation (SO). Sample specimens were collected from each group at 6, 12, 24, 48, and 72 hours after reperfusion. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by an automatic biochemical analyzer. Malondialdehyde (MDA) in liver tissue was measured. Pathological changes in the liver and immunohistochemical staining for survivin were determined with an optical microscope. The ALT levels in the IP and IR groups after reperfusion at each time were higher than those in the SO group (P<0.05), whereas after reperfusion for 6 and 12 hours, the ALT levels in the IP group were lower than those in the IR group (P<0.05). The AST levels in all IP and IR groups were higher than those in the SO group (P<0.05), whereas after reperfusion for 12, 24, 48 and 72 hours, the AST levels in the IP group were lower than those in the IR group (P<0.05). The MDA concentrations after reperfusion in the IP group were lower than those in the IR group (P<0.05), though the MDA concentrations in the IP and IR groups increased in contrast to those in the SO group after reperfusion at each time (P<0.05). After reperfusion for 12, 24, 48 and 72 hours, the number of survivin-positive cells was larger in the IP and IR groups than in the SO group (P<0.05). After reperfusion for 12, 24, and 48 hours the number of survivin-positive cells in the IP group increased compared with that in the IR group (P<0.05). IR increases the protein expression of survivin in liver tissue. IP inhibits the accumulation of MDA, advances the expressive phase of survivin protein in hepatic tissue, and improves liver function.

Neuroprotective Effects of the Nonpsychoactive Cannabinoid Cannabidiol in Hypoxic-Ischemic Newborn Piglets

Article

Jul 2008
Pediatr Res

To test the neuroprotective effects of the nonpsychoactive cannabinoid cannabidiol (CBD), piglets received i.v. CBD or vehicle after hypoxia-ischemia (HI: temporary occlusion of both carotid arteries plus hypoxia). Nonhypoxic-ischemic sham-operated piglets remained as controls. Brain damage was studied by near-infrared spectroscopy (NIRS) and amplitude-integrated electroencephalography (aEEG) and by histologic assessment (Nissl and FluoroJadeB staining). In HI+vehicle, HI led to severe cerebral hemodynamic and metabolic impairment, as reflected in NIRS by an increase in total Hb index (THI) and a decrease in the fractional tissue oxygenation extraction (FTOE); in HI+CBD the increase of THI was blunted and FTOE remained similar to SHAM. HI profoundly decreased EEG amplitude, which was not recovered in HI+vehicle, indicating cerebral hypofunction; seizures were observed in all HI+vehicle. In HI+CBD, however, EEG amplitude recovered to 46.4 7.8% baseline and seizures appeared only in 4/8 piglets (both p < 0.05). The number of viable neurons decreased and that of degenerating neurons increased in HI+vehicle; CBD reduced both effects by more than 50%. CBD administration was free from side effects; moreover, CBD administration was associated with cardiac, hemodynamic, and ventilatory beneficial effects. In conclusion, administration of CBD after HI reduced short-term brain damage and was associated with extracerebral benefits.

Nitric Oxide: A Novel Mediator of Inflammation

Article

Dec 1995

Conversion of xanthine dehydrogenase to xanthine oxidase in rat liver and plasma at the onset of reperfusion after ischemia

Article

Jun 1994

The aim of this study was to test whether conversion of xanthine dehydrogenase into xanthine oxidase as induced by fasting, ischemia of the liver or both is an in vivo process or only occurs in vitro in homogenates. For this purpose, the conversion rate of xanthine dehydrogenase into xanthine oxidase was studied in liver homogenates obtained from rats after normal feeding or 24 hr of fasting followed or not by 2 hr of ischemia of the liver. In fed rats, the conversion rate of xanthine dehydrogenase into xanthine oxidase was studied as well in liver homogenates after different periods of reperfusion after 2 hr of ischemia. Homogenization was carried out under strictly controlled conditions, after which the supernatants were incubated at 37 degrees C in buffer for 0 to 5 hr. Enzyme activities were assayed spectrophotometrically by measuring urate production at 295 nm. Conversion started only after 2 to 3 hr of incubation of supernatants of control fed livers, whereas conversion started immediately after 24 hr of fasting. The percentage oxidase activity of total xanthine oxidoreductase activity in ischemic livers from fed animals was slightly higher (26.7% +/- 1.7%; p < 0.05) than in control livers (19.3% +/- 1.4%), whereas the percent oxidase activity in ischemic livers from fasted animals (16.7% +/- 1.0%) was not different from that in control animals (16.8% +/- 1.1%). Ischemia for 2 hr caused in vitro a substantial increase in the conversion rate in supernatants of livers of fed and fasted rats as compared with their controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous Versus Intermittent Portal Triad Clamping for Liver Resection

Article

Apr 1999

The authors compared the intra- and postoperative course of patients undergoing liver resections under continuous pedicular clamping (CPC) or intermittent pedicular clamping (IPC). Reduced blood loss during liver resection is achieved by pedicular clamping. There is controversy about the benefits of IPC over CPC in humans in terms of hepatocellular injury and blood loss control in normal and abnormal liver parenchyma. Eighty-six patients undergoing liver resections were included in a prospective randomized study comparing the intra- and postoperative course under CPC (n = 42) or IPC (n = 44) with periods of 15 minutes of clamping and 5 minutes of unclamping. The data were further analyzed according to the presence (steatosis >20% and chronic liver disease) or absence of abnormal liver parenchyma. The two groups of patients were similar in terms of age, sex, nature of the liver tumors, results of preoperative assessment, proportion of patients undergoing major or minor hepatectomy, and nature of nontumorous liver parenchyma. Intraoperative blood loss during liver transsection was significantly higher in the IPC group. In the CPC group, postoperative liver enzymes and serum bilirubin levels were significantly higher in the subgroup of patients with abnormal liver parenchyma. Major postoperative deterioration of liver function occurred in four patients with abnormal liver parenchyma, with two postoperative deaths. All of them were in the CPC group. This clinical controlled study clearly demonstrated the better parenchymal tolerance to IPC over CPC, especially in patients with abnormal liver parenchyma.

Hepatic ischemia-reperfusion injury - Reply

Article

Mar 2001
AM J SURG

The morbidity associated with liver transplantation and major hepatic resections is partly a result of ischemia-reperfusion injury. The entire world literature on the subject was searched via Medline. Keywords included reperfusion injury, transplantation, liver resection, nitric oxide, endothelin, cytokines, Kupffer cells, ischemic/ischaemic preconditioning, and nuclear factor-kappa B. An imbalance between endothelin and nitric oxide levels results in failure of the hepatic microcirculation at the onset of reperfusion. Activation of nuclear factor-kappa B in the liver promotes proinflammatory cytokine and adhesion molecule synthesis. These result in oxygen-derived free radical production and neutrophil recruitment, further contributing to cellular injury. Various therapeutic modalities acting on the above mediators have been successfully used to attenuate reperfusion injury in animal models of hepatic transplantation and resection. Application of the knowledge gained from animal models of hepatic ischemia-reperfusion to the clinical setting will improve the outcome of hepatic surgery.

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) up-regulates death receptor 5 (DR5) mediated by NF??B activation in epithelial derived cell lines

Article

Nov 2002

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL/APO-2L) activates nuclear factor kappaB (NFkappaB). This activation is regulated by the recruitment of an adaptor protein Fas associating death domain (FADD) to TRAIL death receptors, death receptor 4 (DR4, TRAIL-R1) and death receptor 5 (DR5 TRAIL-R2). This leads to recruitment of caspase 8 and receptor interacting protein (RIP) to the receptor complex. Upon recruitment of caspase 8 and RIP, NFkappaB inducing kinase (NIK) becomes activated causing NFkappaB activation. The role of TRAIL induced NFkappaB activation in epithelial cells is unknown. Herein we demonstrate that TRAIL increases expression of DR5 in human embryonic kidney (HEK) 293, MCF-7 and MDA MB 231 epithelial cell lines while DR4 expression remains unchanged. Blockage of NFkappaB activation either by expression of dominant negative IkappaB or treatment with proteasome inhibitor lactacystin eliminates TRAIL induced DR5 expression. Expression of FADD dominant negative in HEK 293 cells that prevents the recruitment of caspase 8 and RIP to TRAIL death receptors also eliminates this increase. By over expression of the p65 subunit of NFkappaB that increases NFkappaB transcriptional activity, DR5 expression was increased compared to vector alone expressing cells. By blocking TRAIL induced NFkappaB activation, the sensitivity of cells to undergo TRAIL induced apoptosis was significantly decreased. Conversely, the amount of TRAIL induced apoptosis was increased in HEK 293 cells over expressing p65 subunit of NFkappaB. Finally blockage of NFkappaB activation eliminates the synergistic apoptotic response of TRAIL and etoposide. Thus, TRAIL mediated NFkappaB activation increases DR5 expression thereby amplifying the apoptotic response of TRAIL in epithelial derived cells.

Death Receptor Activation-Induced Hepatocyte Apoptosis and Liver Injury

Article

Oct 2003

The TNFalpha receptor super-family consists of several members sharing a sequence homology in a unique function domain, the death domain, which is located in the intracellular portion of the receptor. These so-called death receptors, including Fas, TNF-R1 and TRAIL-R1/TRAIL-R2, are expressed on hepatocytes. When stimulated by their ligands, FasL, TNFalpha or TRAIL, respectively, the death receptors can activate multiple death domain-initiated apoptosis programs, including both extrinsic and intrinsic pathways. A cascade of caspases is activated, which cleave proteins important for the cell structure and function. Activation of the intrinsic pathway also leads to mitochondrial release of several apoptotic proteins and mitochondrial dysfunction, which kill the cell through both caspase-dependent and caspase-independent mechanisms. Death receptor-induced hepatocyte apoptosis contributes to the development of a number of liver diseases, including viral hepatitis, inflammatory hepatitis, Wilson's disease, alcoholic liver disease, endotoxiemia-induced liver failure and ischemia/reperfusion-induced liver damage. This article comprehensively reviews the mechanisms of induction and regulation of death receptor-initiated apoptosis in hepatocytes, examines how these molecular events affect our understanding of the pathogenesis of these diseases and further discusses the potential therapeutic application of the knowledge. We hope we can provide a cohesive and integrated perspective on the many aspects of these complicated processes.

Oral anti-inflammatory activity of cannabidiol, a non-psychoactive constituent of Cannabis, in acute carrageenan-induced inflammation in the rat paw

Article

Apr 2004

Cannabidiol, the major non-psychoactive component of marijuana, has various pharmacological actions of clinical interest. It is reportedly effective as an anti-inflammatory and anti-arthritic in murine collagen-induced arthritis. The present study examined the anti-inflammatory and anti-hyperalgesic effects of cannabidiol, administered orally (5–40 mg/kg) once a day for 3 days after the onset of acute inflammation induced by intraplantar injection of 0.1 ml carrageenan (1% w/v in saline) in the rat. At the end of the treatment prostaglandin E2 (PGE2) was assayed in the plasma, and cyclooxygenase (COX) activity, production of nitric oxide (NO; nitrite/nitrate content), and of other oxygen-derived free radicals (malondialdehyde) in inflamed paw tissues. All these markers were significantly increased following carrageenan. Thermal hyperalgesia, induced by carrageenan and assessed by the plantar test, lasted 7 h. Cannabidiol had a time- and dose-dependent anti-hyperalgesic effect after a single injection. Edema following carrageenan peaked at 3 h and lasted 72 h; a single dose of cannabidiol reduced edema in a dose-dependent fashion and subsequent daily doses caused further time- and dose-related reductions. There were decreases in PGE2 plasma levels, tissue COX activity, production of oxygen-derived free radicals, and NO after three doses of cannabidiol. The effect on NO seemed to depend on a lower expression of the endothelial isoform of NO synthase. In conclusion, oral cannabidiol has a beneficial action on two symptoms of established inflammation: edema and hyperalgesia.

Nitric oxide protects rat hepatocytes against reperfusion injury mediated by the mitochondrial permeability transition

Article

Jun 2004

We investigated the effects of nitric oxide (NO) on hepatocellular killing after simulated ischemia/reperfusion and characterized signaling factors triggering cytoprotection by NO. Cultured rat hepatocytes were incubated in anoxic Krebs-Ringer-HEPES buffer at pH 6.2 for 4 hours and reoxygenated at pH 7.4 for 2 hours. During reoxygenation, some hepatocytes were exposed to combinations of NO donors (S-nitroso-N-acetylpenicillamine [SNAP] and others), a cGMP analogue (8-bromoguanosine-3,5-cGMP [8-Br-cGMP]), and a cGMP-dependent protein kinase inhibitor (KT5823). Cell viability was determined by way of propidium iodide fluorometry. Inner membrane permeabilization and mitochondrial depolarization were monitored by confocal microscopy. SNAP, but not oxidized SNAP, increased cGMP during reperfusion and decreased cell killing. Other NO donors and 8-Br-cGMP also prevented cell killing. Both guanylyl cyclase and cGMP-dependent kinase inhibition blocked the cytoprotection of NO. However, 5-hydroxydecanoate and diazoxide- mitochondrial K(ATP) channel modulators-did not affect NO-dependent cytoprotection or reperfusion injury. During reoxygenation, confocal microscopy showed mitochondrial repolarization, followed by depolarization, inner membrane permeabilization, and cell death. In the presence of either SNAP or 8-Br-cGMP, mitochondrial repolarization was sustained after reperfusion preventing inner membrane permeabilization and cell death. In isolated rat liver mitochondria, a cGMP analogue in the presence of a cytosolic extract and adenosine triphosphate blocked the Ca(2+)-induced mitochondrial permeability transition (MPT), an effect that was reversed by KT5823. In conclusion, NO prevents MPT-dependent necrotic killing of ischemic hepatocytes after reperfusion through a guanylyl cyclase and cGMP-dependent kinase signaling pathway, events that may represent the target of NO cytoprotection in preconditioning.

Evidence for novel cannabinoid receptors

Article

Jun 2005
PHARMACOL THERAPEUT

Cannabinoids, including the bioactive constituents of the marijuana plant, their synthetic analogs, and endogenous lipids with cannabinoid-like activity, produce their biological effects by interacting with specific receptors. To date, two G protein-coupled cannabinoid receptors have been identified by molecular cloning, CB1 receptors mainly expressed in the brain and mediating most of the neurobehavioral effects of cannabinoids and CB2 receptors expressed by immune and hematopoietic tissues. Recent findings indicate that some cannabinoid effects are not mediated by either CB1 or CB2 receptors, and in some cases there is compelling evidence to implicate additional receptors in these actions. These include transient receptor potential vanilloid 1 (TRPV1) receptors and as-yet-unidentified receptors implicated in the endothelium-dependent vasodilator effect of certain cannabinoids and in the presynaptic inhibition of glutamatergic neurotransmission in the hippocampus. The case for these additional receptors is being reviewed here.

The case for survivin as a regulator of microtubule dynamics and cell-death decisions

Article

Jan 2007
CURR OPIN CELL BIOL

Dario Altieri

Survivin has aroused keen interest in disparate areas of basic and translational research. This stems from the complexity of a 'survivin network', which appears to intersect multiple pathways of cell division, resistance to apoptosis, surveillance checkpoints and adaptation to unfavorable environments. Such intricacy has also engendered different models for survivin function and its implications. As antagonists of survivin are being evaluated in the clinic, a critical reassessment of the pathway, especially with respect to cell division and cell survival, is now a priority. Building a unifying model to reconcile the differing views on survivin will aid in the design and interpretation of molecularly based clinical trials targeting this network in humans.

Melatonin abates liver ischemia/reperfusion injury by improving the balance between nitric oxide and endothelin

Article

Dec 2006
HEPATOB PANCREAT DIS

Melatonin exerts complex physiological and pharmacological effects on multiple systems and organs. We hypothesized that melatonin might abate ischemia/reperfusion (I/R) injury in the liver by inhibiting excessive oxidative stress and keeping nitric oxide (NO) from being scavenged by free radicals. The aim of the present study was to investigate whether melatonin protects the liver from I/R injury and, if so, by what underlying mechanism. Under anesthesia, Wistar rats were intraperitoneally injected with 20 mg/kg melatonin (dissolved in physiological saline containing 4% ethanol, Mel group), 4% alcohol (Alc group), or physiological saline (NS group). The artery, portal vein and bile duct of the left lobe of the liver were clamped for 60 minutes and then released. At different time points after I/R, the rats were sacrificed and blood samples were collected to measure the levels of serum alanine aminotransferase (ALT), lactic dehydrogenase (LDH), and NO. Hepatic tissue samples were collected for measuring endothelin expression by immunohistochemical staining and for routine morphological and histological examination. The levels of both ALT and LDH in the Mel group were significantly reduced for up to 24 hours after I/R compared with the Alc and NS groups (P<0.05). The levels of NO in the Mel group were significantly elevated for up to 12 hours after I/R relative to the NS group (P<0.05). The NO levels were also elevated at 0.5 and 6 hours after I/R in the Alc group (P<0.05). The immunohistochemical staining of hepatic tissue showed that endothelin-positive cells were significantly fewer in the Mel group than in the Alc and NS groups at 6 hours after I/R (P<0.01). The necrosis of hepatocytes and the destruction of hepatic cords in the Alc and NS groups were greatly improved in Mel-treated rats, which is in concert with our functional data. Pretreatment with melatonin increased NO bioavailability and decreased endothelin expression, and consequently played a protective role in preserving both liver function and structure during ischemia and reperfusion injury.

Protection of hepatic cells from apoptosis induced by ischemia/reperfusion injury by protein therapeutics

Article

Mar 2007

Aim: Apoptosis is involved in hepatic ischemia/reperfusion injury. The protein FNK, constructed from an anti-apoptotic protein Bcl-xL, exhibits the stronger anticell death activity. We evaluated the effect of FNK on apoptosis after hepatic ischemia and reperfusion, using FNK-overexpressing transgenic mice and the HIV/Tat protein-transduction-domain (PTD) that mediates the introduction of FNK into cells when fused with FNK (PTD-FNK). Methods: Mice were given hepatic ischemic insult for 90 min followed by reperfusion for 3 h. FNK overexpression was determined by immunohistochemistry and Western blot. PTD-FNK was intraperitoneally injected into wild mice 3 h before the insult. Liver injury was determined by the caspase activation, DNA fragmentation, and hematoxylin–eosin and terminal deoxynucleotidyl transferase-mediated dUTP- digoxigenin nick-end labelling (TUNEL) stainings. Results: In FNK-transgenic mice, FNK overexpression inhibited the activation of caspase 3/caspase 3-like activity and DNA fragmentation caused by the injury. In wild mice preinjected with PTD-FNK, PTD-FNK significantly inhibited the caspase activation and DNA fragmentation, reduced the area of liver vacuolization, and protected hepatic cells surrounding blood vessels, irrespective of central or portal veins, from the ischemia/reperfusion damage. Conclusions: FNK inhibits apoptotic death due to the ischemia/reperfusion injury. Our results provide the reasonable expectation of therapeutic protein PTD-FNK for clinical applications, such as transplantation, to protect against ischemia/reperfusion injury.

Effect of Trolox on altered vasoregulatory gene expression in hepatic ischemia/reperfusion

Article

Mar 2004

This study was designed to investigate the effect of Trolox, a hydrophilic analogue of vitamin E, on the alteration of vasoregulatory gene expression during hepatic ischemia and reperfusion (I/R). Rats were subjected to 60 min of hepatic ischemia in vivo. The rats were treated intravenously with Trolox (2.5 mg/kg) or the vehicle as a control 5 min before reperfusion. Liver samples were obtained 5 h after reperfusion for a RT-PCR analysis on the mRNA for the genes of interest. These mRNA peptides are endothelin-1 (ET-1), potent vasoconstrictor peptide, its receptor ET(A) and ET(B), vasodilator endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), heme oxygenase-1 (HO-1), tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase-2 (COX-2). It was seen that serum alanine aminotransferase and lipid peroxidation levels were markedly increased after I/R and Trolox significantly suppressed this increase. In contrast, the glutathione concentration decreased in the I/R group, and this decrease was inhibited by Trolox. ET-1 mRNA expression was increased by I/R, an increase which was prevented by Trolox. The mRNA levels for ET(A) receptor was significantly decreased, whereas ET(B) receptor transcript increased in the I/R group. The increase in ET(A) was prevented by Trolox. The mRNA levels for iNOS and HO-1 significantly increased in the I/R group and Trolox attenuated this increase. There were no significant differences in eNOS mRNA expression among any of the experimental groups. The mRNA levels for COX-2 and TNF-alpha significantly increased in I/R group and Trolox also attenuated this increase. Our findings suggest that I/R induces an imbalanced hepatic vasoregulatory gene expression and Trolox ameliorates this change through its free radical scavenging activity.

Impacting tumor cell-fate by targeting the inhibitor of apoptosis protein survivin Nitric oxide protects rat he-patocytes against reperfusion injury mediated by the mitochondrial permeability transition

Jan 2004
1533-1543

R J Kelly
A Lopez-Chavez
D Citrin
J E Janik
J C Morris

Kelly, R.J., Lopez-Chavez, A., Citrin, D., Janik, J.E., Morris, J.C., 2011. Impacting tumor cell-fate by targeting the inhibitor of apoptosis protein survivin. Mol. Cancer 10, 35. Kim, J.S., Ohshima, S., Pediaditakis, P., Lemasters, J.J., 2004. Nitric oxide protects rat he-patocytes against reperfusion injury mediated by the mitochondrial permeability transition. Hepatology 39, 1533–1543.

Therapeutic potential of cannabidiol against ischemia/reperfusion liver injury in rats

Abstract

No full-text available

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