Nonpsychoactive Cannabinoid Cannabidiol Research Articles

Cannabinoids and healthy ageing: the potential for extending healthspan and lifespan in preclinical models with an emphasis on Caenorhabditis elegans.

There is a significant global upsurge in the number and proportion of older persons in the population. With this comes an increasing prevalence of age-related conditions which pose a major challenge to healthcare systems. The development of anti-ageing treatments may help meet this challenge by targeting the ageing process which is a common denominator to many health problems. Cannabis-like compounds (cannabinoids) are reported to improve quality of life and general well-being in human trials, and there is increasing preclinical research highlighting that they have anti-ageing activity. Moreover, preclinical evidence suggests that endogenous cannabinoids regulate ageing processes. Here, we review the anti-ageing effects of the cannabinoids in various model systems, including the most extensively studied nematode model, Caenorhabditis elegans. These studies highlight that the cannabinoids lengthen healthspan and lifespan, with emerging evidence that they may also hinder the development of cellular senescence. The non-psychoactive cannabinoid cannabidiol (CBD) shows particular promise, with mechanistic studies demonstrating it may work through autophagy induction and activation of antioxidative systems. Furthermore, CBD improves healthspan parameters such as diminishing age-related behavioural dysfunction in models of both healthy and accelerated ageing. Translation into mammalian systems provides an important next step. Moreover, looking beyond CBD, future studies could probe the multitude of other cannabis constituents for their anti-ageing activity.

Identification of histone acetyltransferase genes responsible for cannabinoid synthesis in hemp

BackgroundHistone acetyltransferases (HATs) play an important role in plant growth and development, stress response, and regulation of secondary metabolite biosynthesis. Hemp (Cannabis sativa L.) is famous for its high industrial, nutritional, and medicinal value. It contains non-psychoactive cannabinoid cannabidiol (CBD) and cannabinol (CBG), which play important roles as anti-inflammatory and anti-anxiety. At present, the involvement of HATs in the regulation of cannabinoid CBD and CBG synthesis has not been clarified.MethodsThe members of HAT genes family in hemp were systematically analyzed by bioinformatics analysis. In addition, the expression level of HATs and the level of histone acetylation modification were analyzed based on transcriptome data and protein modification data. Real-time quantitative PCR was used to verify the changes in gene expression levels after inhibitor treatment. The changes of CBD and CBG contents after inhibitor treatment were verified by HPLC-MS analysis.ResultsHere, 11 HAT genes were identified in the hemp genome. Phylogenetic analysis showed that hemp HAT family genes can be divided into six groups. Cannabinoid synthesis genes exhibited spatiotemporal specificity, and histones were acetylated in different inflorescence developmental stages. The expression of cannabinoid synthesis genes was inhibited and the content of CBD and CBG declined by 10% to 55% in the samples treated by HAT inhibitor (PU139). Results indicated that CsHAT genes may regulate cannabinoid synthesis through altering histone acetylation.ConclusionsOur study provides genetic information of HATs responsible for cannabinoid synthesis, and offers a new approach for increasing the content of cannabinoid in hemp.

Therapeutic Potential of Cannabidiol, Cannabidiolic Acid, and Cannabidiolic Acid Methyl Ester as Treatments for Nausea and Vomiting.

Introduction: Nausea and vomiting are the most distressing symptoms reported by oncology patients undergoing anticancer treatment. With the currently available treatments, vomiting and especially nausea remain problematic, highlighting the need for alternative treatments. Discussion: Here we review in vitro and in vivo evidence for the effectiveness of the nonpsychoactive cannabinoid cannabidiol (CBD) in managing nausea and vomiting. In addition, we also review the evidence for CBD's acidic precursor, cannabidiolic acid (CBDA), and a methylated version of CBDA (CBDA-ME) in these phenomena. Finally, we explore the potential role of CBD in the treatment of cannabinoid hyperemesis syndrome. Conclusions: CBD has demonstrated efficacy in reducing nausea and vomiting, with CBDA and CBDA-ME being more potent. The data suggest a need for these compounds to be evaluated in clinical trials for their ability to reduce nausea and/or vomiting.

Evaluation of repeated or acute treatment with cannabidiol (CBD), cannabidiolic acid (CBDA) or CBDA methyl ester (HU-580) on nausea and/or vomiting in rats and shrews

When acutely administered intraperitoneally, the non-psychoactive cannabinoid cannabidiol (CBD), its acidic precursor cannabidiolic acid (CBDA) and a stable methyl ester of CBDA (HU-580) reduce lithium chloride (LiCl)-induced conditioned gaping in male rats (a selective preclinical model of acute nausea) via activation of the serotonin 1A (5-HT1A) receptor. To utilise these compounds to manage nausea in the clinic, we must determine if their effectiveness is maintained when injected subcutaneously (s.c) and when repeatedly administered. First, we compared the effectiveness of each of these compounds to reduce conditioned gaping following repeated (7-day) and acute (1-day) pretreatments and whether these anti-nausea effects were mediated by the 5-HT1A receptor. Next, we assessed whether the effectiveness of these compounds can be maintained when administered prior to each of 4 conditioning trials (once per week). We also evaluated the ability of repeated CBD (7 days) to reduce LiCl-induced vomiting in Suncus murinus. Finally, we examined whether acute CBD was equally effective in male and female rats. Both acute and repeated (7 day) s.c. administrations of CBD (5 mg/kg), CBDA (1 μg/kg) and HU-580 (1 μg/kg) similarly reduced LiCl-induced conditioned gaping, and these effects were blocked by 5HT1A receptor antagonism. When administered over 4 weekly conditioning trials, the anti-nausea effectiveness of each of these compounds was also maintained. Repeated CBD (5 mg/kg, s.c.) maintained its anti-emetic efficacy in S. murinus. Acute CBD(5 and 20 mg/kg, s.c.) administration reduced LiCl-induced conditioned gaping similarly in male and female rats. When administered repeatedly (7 days), CBD, CBDA and HU-580 did not lose efficacy in reducing nausea and continued to act via agonism of the 5-HT1A receptor. When administered across 4 weekly conditioning trials, they maintained their effectiveness in reducing LiCl-induced nausea. Repeated CBD also reduced vomiting in shrews. Finally, CBD's anti-nausea effects were similar in male and female rats. This suggests that these cannabinoids may be useful anti-nausea and anti-emetic treatments for chronic conditions, without the development of tolerance.

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

The endocannabinoid system (ECS) has emerged in recent years as a potential treatment target for alcohol use disorders (AUD). In particular, the nonpsychoactive 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.

Cannabidiol directly targets mitochondria and disturbs calcium homeostasis in acute lymphoblastic leukemia

Anticancer properties of non-psychoactive cannabinoid cannabidiol (CBD) have been demonstrated on tumors of different histogenesis. Different molecular targets for CBD were proposed, including cannabinoid receptors and some plasma membrane ion channels. Here we have shown that cell lines derived from acute lymphoblastic leukemia of T lineage (T-ALL), but not resting healthy T cells, are highly sensitive to CBD treatment. CBD effect does not depend on cannabinoid receptors or plasma membrane Ca2+-permeable channels. Instead, CBD directly targets mitochondria and alters their capacity to handle Ca2+. At lethal concentrations, CBD causes mitochondrial Ca2+ overload, stable mitochondrial transition pore formation and cell death. Our results suggest that CBD is an attractive candidate to be included into chemotherapeutic protocols for T-ALL treatment.

Anti-inflammatory agents for smoking cessation? Focus on cognitive deficits associated with nicotine withdrawal in male mice

Nicotine withdrawal is associated with cognitive deficits including attention, working memory, and episodic memory impairments. These cognitive deficits are a hallmark of nicotine abstinence which could be targeted in order to prevent smoking relapse. The underlying mechanisms, however, are poorly understood. In this study, memory impairment was observed in mice 4 days after the precipitation of nicotine withdrawal by the nicotinic antagonist mecamylamine. The presence of cognitive deficits correlated with microglial activation in the hippocampus and the prefrontal cortex. Moreover, an increased expression of neuroinflammatory markers including IL1β, TNFα and IFNγ was found in both memory-related brain regions. Notably, flow cytometric analysis also revealed an enhancement of TNFα and IFNγ plasmatic levels at the same time point during nicotine withdrawal. Impaired neurogenesis, as shown by reduction in the expression of the endogenous cell proliferation marker Ki67 and the early neuron marker doublecortin, was also associated with nicotine abstinence. Treatment with the non-psychoactive cannabinoid cannabidiol abolished memory impairment of nicotine withdrawal and microglia reactivity, reduced the expression of IL1β and IFNγ in the hippocampus and the prefrontal cortex, respectively, and normalized Ki67 levels. The nonsteroidal anti-inflammatory drug indomethacin also prevented cognitive deficits and microglial reactivity during withdrawal. These data underline the usefulness of anti-inflammatory agents to improve cognitive performance during early nicotine abstinence.

The non-psychoactive phytocannabinoid cannabidiol (CBD) attenuates pro-inflammatory mediators, T cell infiltration, and thermal sensitivity following spinal cord injury in mice

We evaluated the effects of the non-psychoactive cannabinoid cannabidiol (CBD) on the inflammatory response and recovery of function following spinal cord injury (SCI). Female C57Bl/6 mice were exposed to spinal cord contusion injury (T9-10) and received vehicle or CBD (1.5 mg/kg IP) injections for 10 weeks following injury. The effect of SCI and CBD treatment on inflammation was assessed via microarray, qRT-PCR and flow cytometry. Locomotor and bladder function and changes in thermal and mechanical hind paw sensitivity were also evaluated. There was a significant decrease in pro-inflammatory cytokines and chemokines associated with T-cell differentiation and invasion in the SCI-CBD group as well as a decrease in T cell invasion into the injured cord. A higher percentage of SCI mice in the vehicle-treated group (SCI-VEH) went on to develop moderate to severe (0–65.9% baseline thermal threshold) thermal sensitivity as compared with CBD-treated (SCI-CBD) mice. CBD did not affect recovery of locomotor or bladder function following SCI. Taken together, CBD treatment attenuated the development of thermal sensitivity following spinal cord injury and this effect may be related to protection against pathological T-cell invasion.

HU-446 and HU-465, Derivatives of the Non-psychoactive Cannabinoid Cannabidiol, Decrease the Activation of Encephalitogenic T Cells.

Cannabidiol (CBD), the non-psychoactive cannabinoid, has been previously shown by us to decrease peripheral inflammation and neuroinflammation in mouse experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). Here we have studied the anti-inflammatory effects of newly synthesized derivatives of natural (-)-CBD ((-)-8,9-dihydro-7-hydroxy-CBD; HU-446) and of synthetic (+)-CBD ((+)-8,9-dihydro-7-hydroxy-CBD; HU-465) on activated myelin oligodendrocyte glycoprotein (MOG)35-55-specific mouse encephalitogenic T cells (T(MOG) ) driving EAE/MS-like pathologies. Binding assays followed by molecular modeling revealed that HU-446 has negligible affinity toward the cannabinoid CB1 and CB2 receptors while HU-465 binds to both CB1 and CB2 receptors at the high nanomolar concentrations (Ki = 76.7 ± 5.8 nm and 12.1 ± 2.3 nm, respectively). Both, HU-446 and HU-465, at 5 and 10 μm (but not at 0.1 and 1 μm), inhibited the MOG35-55-induced proliferation of autoreactive T(MOG) cells via CB1/CB2 receptor independent mechanisms. Moreover, both HU-446 and HU-465, at 5 and 10 μm, inhibited the release of IL-17, a key autoimmune cytokine, from MOG35-55-stimulated T(MOG) cells. These results suggest that HU-446 and HU-465 have anti-inflammatory potential in inflammatory and autoimmune diseases.

Targeting multiple cannabinoid anti-tumour pathways with a resorcinol derivative leads to inhibition of advanced stages of breast cancer.

The psychoactive cannabinoid Δ(9) -tetrahydrocannabinol (THC) and the non-psychoactive cannabinoid cannabidiol (CBD) can both reduce cancer progression, each through distinct anti-tumour pathways. Our goal was to discover a compound that could efficiently target both cannabinoid anti-tumour pathways. To measure breast cancer cell proliferation/viability and invasion, MTT and Boyden chamber assays were used. Modulation of reactive oxygen species (ROS) and apoptosis was measured using dichlorodihydrofluorescein and annexin/propidium iodide, respectively, in combination with cell flow cytometry. Changes in protein levels were evaluated using Western analysis. Orthotopic and i.v. mouse models of breast cancer metastasis were used to test the activity of cannabinoids in vivo. CBD reduced breast cancer metastasis in advanced stages of the disease as the direct result of down-regulating the transcriptional regulator Id1. However, this was associated with moderate increases in survival. We therefore screened for analogues that could co-target cannabinoid anti-tumour pathways (CBD- and THC-associated) and discovered the compound O-1663. This analogue inhibited Id1, produced a marked stimulation of ROS, up-regulated autophagy and induced apoptosis. Of all the compounds tested, it was the most potent at inhibiting breast cancer cell proliferation and invasion in culture and metastasis in vivo. O-1663 prolonged survival in advanced stages of breast cancer metastasis. Developing compounds that can simultaneously target multiple cannabinoid anti-tumour pathways efficiently may provide a novel approach for the treatment of patients with metastatic breast cancer.

Cannabidiol inhibits paclitaxel‐induced neuropathic pain through 5‐HT1A receptors without diminishing nervous system function or chemotherapy efficacy

Paclitaxel (PAC) is associated with chemotherapy-induced neuropathic pain (CIPN) that can lead to the cessation of treatment in cancer patients even in the absence of alternate therapies. We previously reported that chronic administration of the non-psychoactive cannabinoid cannabidiol (CBD) prevents PAC-induced mechanical and thermal sensitivity in mice. Hence, we sought to determine receptor mechanisms by which CBD inhibits CIPN and whether CBD negatively effects nervous system function or chemotherapy efficacy. The ability of acute CBD pretreatment to prevent PAC-induced mechanical sensitivity was assessed, as was the effect of CBD on place conditioning and on an operant-conditioned learning and memory task. The potential interaction of CBD and PAC on breast cancer cell viability was determined using the MTT assay. PAC-induced mechanical sensitivity was prevented by administration of CBD (2.5 - 10 mg·kg⁻¹) in female C57Bl/6 mice. This effect was reversed by co-administration of the 5-HT(1A) antagonist WAY 100635, but not the CB₁ antagonist SR141716 or the CB₂ antagonist SR144528. CBD produced no conditioned rewarding effects and did not affect conditioned learning and memory. Also, CBD + PAC combinations produce additive to synergistic inhibition of breast cancer cell viability. Our data suggest that CBD is protective against PAC-induced neurotoxicity mediated in part by the 5-HT(1A) receptor system. Furthermore, CBD treatment was devoid of conditioned rewarding effects or cognitive impairment and did not attenuate PAC-induced inhibition of breast cancer cell viability. Hence, adjunct treatment with CBD during PAC chemotherapy may be safe and effective in the prevention or attenuation of CIPN.

Cannabidiol inhibits angiogenesis by multiple mechanisms

Several studies have demonstrated anti-proliferative and pro-apoptotic actions of cannabinoids on various tumours, together with their anti-angiogenic properties. The non-psychoactive cannabinoid cannabidiol (CBD) effectively inhibits the growth of different types of tumours in vitro and in vivo and down-regulates some pro-angiogenic signals produced by glioma cells. As its anti-angiogenic properties have not been thoroughly investigated to date, and given its very favourable pharmacological and toxicological profile, here, we evaluated the ability of CBD to modulate tumour angiogenesis. Firstly, we evaluated the effect of CBD on human umbilical vein endothelial cell (HUVEC) proliferation and viability - through [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and FACS analysis - and in vitro motility - both in a classical Boyden chamber test and in a wound-healing assay. We next investigated CBD effects on different angiogenesis-related proteins released by HUVECs, using an angiogenesis array kit and an ELISA directed at MMP2. Then we evaluated its effects on in vitro angiogenesis in treated HUVECs invading a Matrigel layer and in HUVEC spheroids embedded into collagen gels, and further characterized its effects in vivo using a Matrigel sponge model of angiogenesis in C57/BL6 mice. CBD induced HUVEC cytostasis without inducing apoptosis, inhibited HUVEC migration, invasion and sprouting in vitro, and angiogenesis in vivo in Matrigel sponges. These effects were associated with the down-modulation of several angiogenesis-related molecules. This study reveals that CBD inhibits angiogenesis by multiple mechanisms. Its dual effect on both tumour and endothelial cells supports the hypothesis that CBD has potential as an effective agent in cancer therapy.

Cannabidiol attenuates cisplatin‐induced nephrotoxicity by decreasing oxidative/nitrosative stress, inflammation and cell death

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 and NOX1,, enhanced ROS generation, nitrotyrosine formation, apoptosis , PARP activity, and inflammation in the kidneys of mice, associated with marked histopathological damage and impaired renal function. Pretreatment of mice with cannabidiol markedly attenuated the cisplatin‐induced oxidative/nitrosative stress, inflammation and cell death in the kidney, and improved renal function. Thus, our results suggest that cannabidiol may represent a promising new protective strategy against cisplatin‐induced nephrotoxicity.

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

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.

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

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.

Cannabidiol attenuates high glucose-induced endothelial cell inflammatory response and barrier disruption

A nonpsychoactive cannabinoid cannabidiol (CBD) has been shown to exert potent anti-inflammatory and antioxidant effects and has recently been reported to lower the incidence of diabetes in nonobese diabetic mice and to preserve the blood-retinal barrier in experimental diabetes. In this study we have investigated the effects of CBD on high glucose (HG)-induced, mitochondrial superoxide generation, NF-kappaB activation, nitrotyrosine formation, inducible nitric oxide synthase (iNOS) and adhesion molecules ICAM-1 and VCAM-1 expression, monocyte-endothelial adhesion, transendothelial migration of monocytes, and disruption of endothelial barrier function in human coronary artery endothelial cells (HCAECs). HG markedly increased mitochondrial superoxide generation (measured by flow cytometry using MitoSOX), NF-kappaB activation, nitrotyrosine formation, upregulation of iNOS and adhesion molecules ICAM-1 and VCAM-1, transendothelial migration of monocytes, and monocyte-endothelial adhesion in HCAECs. HG also decreased endothelial barrier function measured by increased permeability and diminished expression of vascular endothelial cadherin in HCAECs. Remarkably, all the above mentioned effects of HG were attenuated by CBD pretreatment. Since a disruption of the endothelial function and integrity by HG is a crucial early event underlying the development of various diabetic complications, our results suggest that CBD, which has recently been approved for the treatment of inflammation, pain, and spasticity associated with multiple sclerosis in humans, may have significant therapeutic benefits against diabetic complications and atherosclerosis.

CB1 cannabinoid receptor‐mediated modulation of food intake in mice

1 Marijuana's appetite-increasing effects have long been known. Recent research suggests that the CB(1) cannabinoid receptor antagonist SR141716A may suppress appetite. This study represents a further, systematic investigation of the role of CB(1) cannabinoid receptors in the pharmacological effects of cannabinoids on food intake. 2 Mice were food-restricted for 24 h and then allowed access to their regular rodent chow for 1 h. Whereas the CB(1) antagonist SR141716A dose-dependently decreased food consumption at doses that did not affect motor activity, Delta(9)-tetrahydrocannabinol (Delta(9)-THC) increased food consumption at doses that had no effect on motor activity. O-3259 and O-3257, structural analogs of SR141716A, produced effects similar to those of the parent compound. 3 Amphetamine (a known anorectic) and diazepam (a benzodiazepine and CNS depressant) decreased food consumption, but only at doses that also increased or decreased motor activity, respectively. The CB(2) cannabinoid receptor antagonist SR144528 and the nonpsychoactive cannabinoid cannabidiol did not affect food intake nor activity. 4 SR141716A decreased feeding in wild-type mice, but lacked pharmacological activity in CB(1) knockout mice; however, basal food intake was lower in CB(1) knockout mice. Amphetamine decreased feeding in both mouse genotypes. 5 These results suggest that SR141716A may affect the actions of endogenous cannabinoids in regulating appetite or that it may have effects of its own aside from antagonism of cannabinoid effects (e.g., decreased feeding behavior and locomotor stimulation). In either case, these results strongly suggest that CB(1) receptors may play a role in regulation of feeding behavior.

Comparison of Cannabidiol, Antioxidants, and Diuretics in Reversing Binge Ethanol-Induced Neurotoxicity

Binge alcohol consumption in the rat induces substantial neurodegeneration in the hippocampus and entorhinal cortex. Oxidative stress and cytotoxic edema have both been shown to be involved in such neurotoxicity, whereas N-methyl-d-aspartate (NMDA) receptor activity has been implicated in alcohol withdrawal and excitoxic injury. Because the nonpsychoactive cannabinoid cannabidiol (CBD) was previously shown in vitro to prevent glutamate toxicity through its ability to reduce oxidative stress, we evaluated CBD as a neuroprotectant in a rat binge ethanol model. When administered concurrently with binge ethanol exposure, CBD protected against hippocampal and entorhinal cortical neurodegeneration in a dose-dependent manner. Similarly, the common antioxidants butylated hydroxytoluene and alpha-tocopherol also afforded significant protection. In contrast, the NMDA receptor antagonists dizocilpine (MK-801) and memantine did not prevent cell death. Of the diuretics tested, furosemide was protective, whereas the other two anion exchanger inhibitors, L-644,711 [(R)-(+)-(5,6-dichloro2,3,9,9a-tetrahydro 3-oxo-9a-propyl-1H-fluoren-7-yl)oxy acetic acid] and bumetanide, were ineffective. In vitro comparison of these diuretics indicated that furosemide is also a potent antioxidant, whereas the nonprotective diuretics are not. The lack of efficacy of L-644,711 and bumetanide suggests that the antioxidant rather than the diuretic properties of furosemide contribute most critically to its efficacy in reversing ethanol-induced neurotoxicity in vitro, in our model. This study provides the first demonstration of CBD as an in vivo neuroprotectant and shows the efficacy of lipophilic antioxidants in preventing binge ethanol-induced brain injury.

Electrophysiologic properties of the cannabinoids.

The effects of the psychoactive cannabinoid delta 9-tetrahydrocannabinol (THC) and the nonpsychoactive cannabinoid cannabidiol (CBD) were investigated comparatively on electrically caused transcallosal cortical evoked responses, electrically induced limbic after discharges, photically evoked cortical afterdischarges, spontaneous cortical focal epileptic potentials, and spinal monosynaptic reflexes. In each system, THC produced central excitation; for example, the drug's responses ranged from enhancement of synaptic transmission to precipitation of frank convulsions. In addition to central nervous system stimulation, THC usually elicited depression; the qualitative character of the effect of the drug was dependent upon the dosage and the test system. In contrast to THC, cannabidiol generated no CNS excitation: it was either depressant or inert in these test systems. The results clearly demonstrate the complexity of the CNS properties of THC and the selectivity of the depressant properties of cannabidiol; moreover, the data illustrate the wide range of neuropharmacologic responses that potentially any cannabinoid can effect.