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Cannabidiol (CBD) is a non-psychoactive component of Cannabis which has recently received regulatory consideration for the treatment of intractable forms of epilepsy such as the Dravet and the Lennox-Gastaut syndromes. The mechanisms of the antiepileptic effects of CBD are unclear, but several pre-clinical studies suggest the involvement of ion channels. Therefore, we have evaluated the effects of CBD on seven major cardiac currents shaping the human ventricular action potential and on Purkinje fibers isolated from rabbit hearts to assess the in vitro cardiac safety profile of CBD. We found that CBD inhibits with comparable micromolar potencies the peak and late components of the Na V 1.5 sodium current, the Ca V 1.2 mediated L-type calcium current, as well as all the repolarizing potassium currents examined except K ir 2.1. The most sensitive channels were K V 7.1 and the least sensitive were K V 11.1 (hERG), which underly the slow (I Ks ) and rapid (I Kr ) components, respectively, of the cardiac delayed-rectifier current. In the Purkinje fibers, CBD decreased the action potential (AP) duration more potently at half-maximal than at near complete repolarization, and slightly decreased the AP amplitude and its maximal upstroke velocity. CBD had no significant effects on the membrane resting potential except at the highest concentration tested under fast pacing rate. These data show that CBD impacts cardiac electrophysiology and suggest that caution should be exercised when prescribing CBD to carriers of cardiac channelopathies or in conjunction with other drugs known to affect heart rhythm or contractility., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Cannabidiol (CBD) is a biologically active, non-psychotropic component of Cannabis sativa whose popularity has grown exponentially in recent years. Besides a wealth of potential health benefits, ingestion of CBD poses risks for a number of side effects, of which hepatotoxicity and CBD/herb-drug interactions are of particular concern. Here, we investigated the interaction potential between the cannabidiol-rich cannabis extract (CRCE) and methylsulfonylmethane (MSM), a popular dietary supplement, in the mouse model. For this purpose, 8-week-old male C57BL6/J mice received MSM-containing water (80 mg/100 mL) ad libitum for 17 days. During the last three days of treatment, mice received three doses of CRCE administered in sesame oil via oral gavage (123 mg/kg/day). Administration of MSM alone did not result in any evidence of liver toxicity and did not induce expression of mouse cytochrome P450 (CYP) enzymes. Administration of CRCE did produce significant ( p < 0.05) increases in Cyp1a2 , Cyp2b10 , Cyp2c29 , Cyp3a4 , Cyp3a11 , Cyp2c65 , and Cyp2c66 messenger RNA, however, this effect was not amplified by MSM/CRCE co-treatment. Similarly, no evidence of liver toxicity was observed in MSM/CRCE dosed mice. In conclusion, short-term MSM/CRCE co-administration did not demonstrate any evidence of hepatotoxicity in the mouse model.

The present study investigates the interaction between cannabidiol (CBD) oil and three biopesticides: Azatin and two baculovirus formulations (Madex and Helicovex), both separately and in combination, in order to investigate their interaction against adults of four major coleopteran stored-product pests: Sitophilus zeamais (Coleoptera: Curculionidae), Rhyzopertha dominica (Coleoptera: Bostrichidae), Prostephanus truncatus (Coleoptera: Bostrichidae) and Trogoderma granarium (Coleoptera: Dermestidae). CBD, which has been understudied for its insecticidal properties, was applied at three different doses (500, 1500 and 3000 ppm). The biopesticides were administered at 1500 ppm. Interactions in the combined treatments were mathematically estimated as not synergistic and mostly competitive except for the combined treatments of CBD (1500 and 3000 ppm) with Azatin (1500 ppm) which were marked by an additive interaction. In its individual application, CBD oil generated the highest insect mortality while its effect was clearly dose-dependent. The findings reveal a promising effect of CBD oil against these coleopterans which had not been previously tested together.

An interesting and valuable discussion has arisen from our recent article (Lachenmeier et al., 2020) and we are pleased to have the opportunity to expand on the various points we made. Equally important, we wish to correct several important misunderstandings that were made by Kruse and Beitzke (2020) on behalf of the European Industrial Hemp Association (EIHA) that possibly contributed to their concerns about the validity of our data, toxicological assessment and conclusions regarding regulatory status of cannabidiol (CBD) products. First and foremost, our study did only assess the risk of psychotropic Δ 9 -tetrahydrocannabinol (THC) without inclusion of non-psychotropic Δ 9 -tetrahydrocannabinolic acid (THCA). Secondly, as this article will discuss in more detail, there is ample evidence for adverse effects of CBD products, not only in paediatric patients, but also in adult users of over-the-counter CBD products (including inadvertent "high" effects). Thirdly, the exposure and risk assessment was conducted using up-to-date guidelines according to the European Food Safety Authority (EFSA) and the German Federal Institute for Risk Assessment (BfR). And finally, the current legal situation in the European Union, without approval of any hemp extract-containing product according to the Novel Food regulation, actually allows blanket statements that all such products are illegal on the market, and this indeed would imply a general ban on the use and marketing of such products as food or food ingredients until such an approval has been granted. We hope that this reassures the F1000Research readership regarding the validity of our results and conclusions. We are pleased, though, that the EIHA has acknowledged the fact that there are non-compliant CBD products available, but according to our data these are a substantial fraction of the market., Competing Interests: No competing interests were disclosed., (Copyright: © 2021 Lachenmeier DW and Walch SG.)

An interesting and valuable discussion has arisen from our recent article (Lachenmeier et al., 2020) and we are pleased to have the opportunity to expand on the various points we made. Equally important, we wish to correct several important misunderstandings that were made by Kruse and Beitzke (2020) on behalf of the European Industrial Hemp Association (EIHA) that possibly contributed to their concerns about the validity of our data, toxicological assessment and conclusions regarding regulatory status of cannabidiol (CBD) products. First and foremost, our study did only assess the risk of psychotropic Δ 9 -tetrahydrocannabinol (THC) without inclusion of non-psychotropic Δ 9 -tetrahydrocannabinolic acid (THCA). Secondly, as this article will discuss in more detail, there is ample evidence for side effects of CBD products, not only in paediatric patients, but also in adult users of over-the-counter CBD products (including inadvertent "high" effects). Thirdly, the exposure and risk assessment was conducted using up-to-date guidelines according to the European Food Safety Authority (EFSA) and the German Federal Institute for Risk Assessment (BfR). And finally, the current legal situation in the European Union, without approval of any hemp extract-containing product according to the Novel Food regulation, actually allows blanket statements that all such products are illegal on the market, and this indeed would imply a general ban on the use and marketing of such products as food or food ingredients until such an approval has been granted. We hope that this reassures the F1000Research readership regarding the validity of our results and conclusions. We are pleased, though, that the EIHA has acknowledged the fact that there are non-compliant CBD products available, but according to our data these are a substantial fraction of the market., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Lachenmeier DW and Walch SG.)

This Correspondence article is a counterstatement to a Brief Report published by Lachenmeier and co-workers on 17th February 2020 in F1000Research: "Are side effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?". This counterstatement proposes that the authors of that article neither present proof or evidence for the alleged side effects of CBD products (no case reports presented with utilisable data), nor do they show that side effects are due to the presence of THC. Primarily, there is no clear definition of THC because the authors do not explain whether they mean Delta9-THC only (without its precursor tetrahydrocannabinolic acid (THCA)) or total-THC (the sum of Delta9-THC and its precursor THCA, normalised to THC); indeed EU Recommendation 2016/2115 on the monitoring of cannabinoids in food requires the measurement and documentation of the precursor acids complementary to the decarboxylated cannabinoids. The key part of the authors' work - Table 2 with the assessment of the CBD products - leaves the reader in the dark about the nature of "THC". This is all the more concerning because acid-free Delta9-THC is psychotropic but THCA is not. Additionally, the classification of the CBD products ("toxicity assessment") presented is based on the assignment of the quantitative relation to the LOAEL (lowest observed adverse effect level) of THC (2.5 mg of acid-free Delta9-THC per adult and day as assigned by EFSA, 2015). However, many assumptions by Lachenmeier et al. on daily intake of CBD products are questionable, in particular food supplements, where the recommended daily consumption was missing on the label. Finally, the authors of the paper also compare their findings with the German recommendations on maximum levels of total-THC in food, ignoring that those limits refer to total-THC and the ready-to-eat products, and not to the food ingredient itself - in particular hemp tea products., Competing Interests: Competing interests: DK is the President of the European Industrial Hemp Association (EIHA); BB is member of the EIHA Advisory Committee. The EIHA is the European association of the hemp processing industry with about 250 members in more than 30 countries. The EIHA, based in Brussels (Belgium), represents the interests of industrial hemp producers and traders on a pan-European and national level. The industrial hemp sector includes the cultivation and processing of hemp fibres and seeds as well as cannabinoids. The EIHA therefore represents the common interests of hemp farmers, producers and traders working with hemp fibres, shives, seeds, leaves and cannabinoids. EIHA’s main task is to serve, protect and represent the hemp sector in the EU and international policy-making. EIHA covers different areas for the application of hemp, namely its use for construction materials, textiles, cosmetics, feed, food and supplements. EIHA confirms that funding was not granted to this specific piece of research, but was part of the general work of the association’s tasks as stated above., (Copyright: © 2020 Kruse D and Beitzke B.)

Background: Population-based studies suggest increasing rates of concurrent use of vaping products that contain either nicotine or cannabinoids. The aim of this pilot study was to test in vitro the acute inhalation toxicity of vaporized flavored and unflavored nicotine solutions co-administered with cannabidiol (CBD)., Methods: Bronchial epithelial cells (H292) were exposed directly to aerosol generated from electronic cigarettes refilled with propylene glycol only, unflavored nicotine solutions in propylene glycol with and without CBD, as well as to solutions containing only CBD. Cells were also exposed to a commercially available flavored solution containing nicotine and CBD. The in vitro toxicological effects were assessed after exposure using the following methods: 1) a trypan blue exclusion assay (cell viability), 2) neutral red uptake assay (metabolic activity) and 3) ELISA (concentrations of inflammatory mediators)., Results: Unflavored solution containing only CBD was significantly more cytotoxic than unflavored solution containing only nicotine. Unflavored solution containing both CBD and nicotine was significantly more cytotoxic than unflavored solutions with only nicotine. Levels of released cytokines were significantly higher when cells were co-exposed to nicotine and CBD as compared to cells exposed to only nicotine or only CBD. Overall, flavored products showed increased toxicity as compared to unflavored solutions., Conclusions: This pilot in vitro study suggests independent and additive toxic effects of vaporized nicotine and CBD. Observed toxic effects are accentuated by flavorings. Future studies are needed to determine the potential long-term health consequences of concurrent use of vaporized nicotine and cannabis products.

Decidualization, which comprises proliferation and differentiation of endometrial stromal cells (ESCs), is essential for the establishment of a receptive endometrium and pregnancy to occur. A deregulation of decidualization has been associated with miscarriage, infertility and other pregnancy-related disorders. The role of estradiol (E 2 ) on decidualization has already been shown, since it regulates proliferation of ESCs and expression of progesterone receptor. In this study, we investigated the effects of phytocannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), in proliferation and differentiation of ESCs, as well as, in E 2 metabolism/signaling. We found that CBD, but not THC, inhibits ESCs differentiation. We also show that CBD prevents the increase on transcript levels of CYP19A1 gene and the elevation of E 2 levels that are observed in differentiating ESCs. Moreover, we found that CBD presents anti-aromatase activity. In overall, we highlight a novel effect of CBD on human endometrial differentiation, which may lead to infertility problems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Rationale: The behavioural effects elicited by chemical constituents of Cannabis sativa, such as cannabidiol (CBD), on the ventromedial hypothalamus (VMH) are not well understood. There is evidence that VMH neurons play a relevant role in the modulation of unconditioned fear-related defensive behavioural reactions displayed by laboratory animals., Objectives: This study was designed to explore the specific pattern of distribution of the CB 1 receptors in the VMH and to investigate the role played by this cannabinoid receptor in the effect of CBD on the control of defensive behaviours and unconditioned fear-induced antinociception., Methods: A panic attack-like state was triggered in Wistar rats by intra-VMH microinjections of N-methyl-D-aspartate (NMDA). One of three different doses of CBD was microinjected into the VMH prior to local administration of NMDA. In addition, the most effective dose of CBD was used after pre-treatment with the CB 1 receptor selective antagonist AM251, followed by NMDA microinjections in the VMH., Results: The morphological procedures demonstrated distribution of labelled CB 1 receptors on neuronal perikarya situated in dorsomedial, central and ventrolateral divisions of the VMH. The neuropharmacological approaches showed that both panic attack-like behaviours and unconditioned fear-induced antinociception decreased after intra-hypothalamic microinjections of CBD at the highest dose (100 nmol). These effects, however, were blocked by the administration of the CB 1 receptor antagonist AM251 (100 pmol) in the VMH., Conclusion: These findings suggest that CBD causes panicolytic-like effects and reduces unconditioned fear-induced antinociception when administered in the VMH, and these effects are mediated by the CB 1 receptor-endocannabinoid signalling mechanism in VMH.

Cannabis sativa L. contains more than 100 phytocannabinoids that can interact with cannabinoid receptors CB1 and CB2. None of the cannabinoid receptor ligands is entirely CB1- or CB2-specific. The effects of cannabinoids therefore differ not just because of different potency at cannabinoid receptors but also because they can interact with other non-CB1 and non-CB2 targets, such as TRPV1, GPR55, and GPR119. The most studied phytocannabinoid is Δ9-tetrahydrocannabinol (THC). THC is a partial agonist at both cannabinoid receptors, but its psychotomimetic effect is produced primarily via activation of the CB1 receptor, which is strongly expressed in the central nervous system, with the noteworthy exception of the brain stem. Although acute cognitive and other effects of THC are well known, the risk of irreversible neuropsychological effects of THC needs further research to elucidate the association. Unlike THC, phytocannabinoid cannabidiol (CBD) does not appear to have psychotomimetic effects but may interact with some of the effects of THC if taken concomitantly. CBD administered orally has recently undergone well-controlled clinical trials to assess its safety in the treatment of paediatric epilepsy syndromes. Their findings point to increased transaminase levels as a safety issue that calls for postmarketing surveillance for liver toxicity. The aim of this review is to summarise what is known about acute and chronic toxicological effects of both compounds and address the gaps in knowledge about the safety of exogenous cannabinoids that are still open.

Cannabidiol (CBD) is one of the most abundant phytocannabinoids present in the plant Cannabis sativa (marijuana). There have been several studies of CBD in the last few decades, mainly focused on its neuroprotective properties, particularly after the identification of the endocannabinoid system and its participation in the central nervous system. On the other hand, the peripheral effects of CBD, particularly on reproductive physiology, were also evidenced. A narrative review was conducted using the PubMed database to identify studies that analyzed the pharmacological effects of CBD on the male reproductive system of vertebrates and invertebrates. Thirty-two citations (in vivo and in vitro) were identified. Among the vertebrates, the studies were carried out with men, monkeys, rats and mice. Studies with invertebrates are centered exclusively on the sea urchin. The CBD treatment periods include mostly acute and subacute evaluations. Exposure to CBD is associated with a reduction in mammalian testis size, the number of germ and Sertoli cells in spermatogenesis, fertilization rates, and plasma concentrations of hypothalamic, pituitary and gonadal hormones. Moreover, chronic doses of CBD have impaired sexual behavior in mice. From the studies identified in this review, it is possible to conclude that CBD has negative effects on the reproductive system of males. However, knowledge is still limited, and additional research is required to elucidate fully the mechanisms of action, as well as the reversibility of CBD effects on the reproductive system., (© 2019 John Wiley & Sons, Ltd.)

Cannabidiol (CBD) is a natural compound with psychoactive therapeutic properties well described. Conversely, the immunological effects of CBD are still poorly explored. In this study, the potential anti-inflammatory effects and underlying mechanisms of CBD and its analog Dimethyl-Heptyl-Cannabidiol (DMH-CBD) were investigated using RAW 264.7 macrophages. CBD and DMH-CBD suppressed LPS-induced TNF production and NF-kB activity in a concentration-dependent manner. Both compounds reduced the NF-kB activity in a μM concentration range: CBD (IC 50  = 15 μM) and DMH-CBD (IC 50  = 38 μM). However, the concentrations of CBD that mediated NF-kB inhibition were similar to those that cause cytotoxicity (LC 50  = 58 μM). Differently, DMH-CBD inhibited the NF-kB activation without cytotoxic effects at the same concentrations, although it provokes cytotoxicity at long-term exposure. The inhibitory action of the DMH-CBD on NF-kB activity was not related to the reduction in IkBα degradation or either p65 (NF-kB) translocation to the nucleus, although it decreased p38 MAP kinase phosphorylation. Additionally, 8-(3-Chlorostyryl) caffeine (CSC), an A 2A antagonist, reversed the effect of DMH-CBD on NF-kB activity in a concentration-dependent manner. Collectively, our results demonstrated that CBD reduces NF-kB activity at concentrations intimately associated with those that cause cell death, whereas DMH-CBD decreases NF-kB activity at non-toxic concentrations in an A 2A receptor dependent-manner., (Copyright © 2019 Elsevier Inc. All rights reserved.)

While Δ 9 -tetrahydrocannabinol (THC) has been widely studied in the realm of developmental and reproductive toxicology, few studies have investigated potential toxicities from a second widely used cannabis constituent, cannabidiol (CBD). CBD is popularized for its therapeutic potential for reducing seizure frequencies in epilepsy. This study investigated developmental origins of health and disease (DOHaD) via multigenerational gene expression patterns, behavior phenotypes, and reproductive fitness of a subsequent F1 following an F0 developmental exposure of zebrafish (Danio rerio) to THC (0.024, 0.12, 0.6 mg/L; 0.08, 0.4, 2 μM) or CBD (0.006, 0.03, 0.15 mg/L; 0.02, 0.1, 0.5 μM). Embryonic exposure at these concentrations did not cause notable morphological abnormalities in either F0 or F1 generations. However, during key developmental stages (14, 24, 48, 72, and 96 h post fertilization) THC and CBD caused differential expression of c-fos, brain-derived neurotrophic factor (bdnf), and deleted-in-azoospermia like (dazl), while in F1 larvae only CBD differentially expressed dazl. Larval photomotor behavior was reduced (F0) or increased (F1) by THC exposure, while CBD had no effect on F0 larvae, but decreased activity in the unexposed F1 larvae. These results support our hypothesis of cannabinoid-related developmental neurotoxicity. As adults, F0 fecundity was reduced, but it was not in F1 adults. Conversely, in the adult open field test there were no significant effects in F0 fish, but a significant reduction in the time in periphery was seen in F1 fish from the highest THC exposure group. The results highlight the need to consider long-term ramifications of early-life exposure to cannabinoids., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Currently, there is a great interest in the potential medical use of cannabidiol (CBD), a non-intoxicating cannabinoid. Productive pharmacological research on CBD occurred in the 1970s and intensified recently with many discoveries about the endocannabinoid system. Multiple preclinical and clinical studies led to FDA-approval of Epidiolex®, a purified CBD medicine formulated for oral administration for the treatment of infantile refractory epileptic syndromes, by the US Food and Drug Administration in 2018. The World Health Organization considers rescheduling cannabis and cannabinoids. CBD use around the world is expanding for diseases that lack scientific evidence of the drug's efficacy. Preclinical and clinical studies also report adverse effects (AEs) and toxicity following CBD intake., Methods: Relevant studies reporting CBD's AEs or toxicity were identified from PubMed, Cochrane Central, and EMBASE through January 2019. Studies defining CBD's beneficial effects were included to provide balance in estimating risk/benefit., Results: CBD is not risk-free. In animals, CBD AEs included developmental toxicity, embryo-fetal mortality, central nervous system inhibition and neurotoxicity, hepatocellular injuries, spermatogenesis reduction, organ weight alterations, male reproductive system alterations, and hypotension, although at doses higher than recommended for human pharmacotherapies. Human CBD studies for epilepsy and psychiatric disorders reported CBD-induced drug-drug interactions, hepatic abnormalities, diarrhea, fatigue, vomiting, and somnolence., Conclusion: CBD has proven therapeutic efficacy for serious conditions such as Dravet and Lennox-Gastaut syndromes and is likely to be recommended off label by physicians for other conditions. However, AEs and potential drug-drug interactions must be taken into consideration by clinicians prior to recommending off-label CBD., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Cannabidiol (CBD) and cannabidivarin (CBDV) are natural cannabinoids which are consumed in increasing amounts worldwide in cannabis extracts, as they prevent epilepsy, anxiety, and seizures. It was claimed that they may be useful in cancer therapy and have anti-inflammatory properties. Adverse long-term effects of these drugs (induction of cancer and infertility) which are related to damage of the genetic material have not been investigated. Therefore, we studied their DNA-damaging properties in human-derived cell lines under conditions which reflect the exposure of consumers. Both compounds induced DNA damage in single cell gel electrophoresis (SCGE) experiments in a human liver cell line (HepG2) and in buccal-derived cells (TR146) at low levels (≥ 0.2 µM). Results of micronucleus (MN) cytome assays showed that the damage leads to formation of MNi which reflect chromosomal aberrations and leads to nuclear buds and bridges which are a consequence of gene amplifications and dicentric chromosomes. Additional experiments indicate that these effects are caused by oxidative base damage and that liver enzymes (S9) increase the genotoxic activity of both compounds. Our findings show that low concentrations of CBD and CBDV cause damage of the genetic material in human-derived cells. Furthermore, earlier studies showed that they cause chromosomal aberrations and MN in bone marrow of mice. Fixation of damage of the DNA in the form of chromosomal damage is generally considered to be essential in the multistep process of malignancy, therefore the currently available data are indicative for potential carcinogenic properties of the cannabinoids.

Pet exposure to marijuana-containing products-both recreational and medicinal-along with exposure to extracts such as cannabidiol is increasing in conjunction with greater accessibility. Cannabis products are even sold for use in pets. In addition, exposure to illegal synthetic cannabinoids remains concerning. Veterinarians need to be able to recognize associated clinical signs and understand when cases have the potential for severity. This article provides a brief history of cannabis along with a review of the endocannabinoid system, common cannabis products, expected clinical signs, and medical treatment approaches associated with cannabis exposure in pets., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cannabidiol (CBD) is a potent substance extracted from Cannabis sativa. As it has been suggested that marijuana can affect the reproductive system, we decided to assess the effects of chronic CBD exposure on the male reproductive system in an animal model. 21-day old male Swiss mice received CBD for 34 consecutive days at doses (p.o.) of either 15 or 30 mg/kg, and a control group received sunflower oil. Body weight gain and circulating progesterone concentration did not significantly change in CBD-treated animals. In the sexual behavior analysis, the CBD 15 group presented a delay in performing the first mount and intromission, and a reduced number of mounts and ejaculations. The CBD 30 group showed a 30% reduction in fertility rate and a 23% reduction in the number of litters. Our results indicate that chronic CBD exposure promotes functional impairment of the reproductive system of male Swiss mice., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Children and adults with frequent and severe episodes of epilepsy that do not respond to standard treatments (such as carbamazepine, phenytoin and valproate) have long been prescribed cannabidiol (CBD) as an anticonvulsant drug. However, the safety of its chronic use in relation to reproduction has not been fully examined. This study aimed to assess the effects of chronic CBD exposure on the male reproductive system. CBD was orally administered to 21-day-old male Swiss mice at doses of 15 and 30 mg kg -1 daily (CBD 15 and 30 groups, respectively), with a control group receiving sunflower oil, for 34 consecutive days. After a 35 day recovery period, the following parameters were evaluated: weight of reproductive organs, testosterone concentration, spermatogenesis, histomorphometry, daily sperm production and its morphology. The CBD 30 group had a 76% decrease in total circulating testosterone, but it remained within the physiological normal range (240-1100 ng dl -1 ). CBD treatment induced a significant increase in the frequency of stages I-IV and V-VI of spermatogenesis, and a decrease in the frequency of stages VII-VIII and XII. A significant decrease in the number of Sertoli cells was observed only in the CBD 30 group. In both CBD groups the number of spermatozoa in the epididymis tail was reduced by 38%, sperm had head abnormalities, and cytoplasmic droplets were observed in the medial region of flagellum. These results indicated that chronic CBD exposure was associated with changes in the male reproductive system, suggesting its reproductive toxicity., (Copyright © 2018 John Wiley & Sons, Ltd.)

Cannabidiol (CBD) is a non-psychotomimetic compound of the Cannabis sativa that has been used for the treatment of severe epilepsy as well as other diseases of nervous system. However, toxicity studies of CBD have great relevance to guarantee the patients safety. In this context, morphological analyses of zebrafish can contribute to evaluate the teratogenic potential, as well as evaluation of acetylcholinesterase activity and motor activity of zebrafish are valuable tools to verify the neurotoxicity potential. In the present work, we use this methodology to test the toxicity of CBD to zebrafish embryos. No malformation was observed in morphological analysis of embryos exposed to all tested concentrations of CBD. Although, twenty per cent of embryos exposed to maximal dose of CBD (300 μg/L) hatched after 96hpf, while embryos in control solution had already hatched in this period. Embryos exposed to CBD did not show differences in acetylcholinesterase activity, but embryos exposed to CBD 20-300 μg/L were 1.4 up to 1.7-fold more active when compared to the control. Despite that, at 48 hpf, motor activity returned to control values. Our results suggest that the effects observed after CBD exposure are intimately related to CB1 receptor that is present in zebrafish since early stages of development. The present work showed early light effects induced by CBD exposure in concentrations that did not alter biochemical activity., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Marijuana is one of the most commonly used illicit recreational drugs and is widely used for medicinal purposes. The psychoactive ingredient in marijuana is ∆ 9 -tetrahydrocannabinol (∆ 9 -THC), whereas the major non-psychoactive ingredient is cannabidiol (CBD). Here, we exposed zebrafish embryos to ∆ 9 -THC or CBD for 5 hours during the critical stage of development known as gastrulation. Embryos were allowed to develop normally and were examined at 2 and 5 days post fertilization. THC and CBD treated embryos exhibited reduced heart rates, axial malformations and shorter trunks. Cannabinoid treatment altered synaptic activity at neuromuscular junctions (NMJs), and fluorescent labelling of primary and secondary motor neurons indicated a change in branching patterns and a reduction in the number of axonal branches in the trunk musculature. Furthermore, there were alterations in the α-bungarotoxin labelling of nicotinic acetylcholine receptors at NMJs. Locomotion studies show that larvae exposed to THC or CBD during gastrulation exhibited drastic reductions in the number of C-start escape responses to sound stimuli, but not to touch stimuli. Together these findings indicate that zebrafish embryos exposed to ∆ 9 -THC or CBD during the brief but critical period of gastrulation exhibited alterations in heart rate, motor neuronal morphology, synaptic activity at the NMJ and locomotor responses to sound.

Cannabidiol (CBD) has gained much attention in the past several years for its therapeutic potential in the treatment of drug-resistant epilepsy, such as Dravet syndrome. Although CBD has shown anecdotal efficacy in reducing seizure frequency, little is known regarding the potential adverse side effects of CBD on physiology, development, organogenesis, or behavior. The goal of this project was to compare the relative morphological, behavioral, and gene expression phenotypes resulting after a developmental exposure to Δ9-tetrahydrocannabinol (THC) or CBD. Zebrafish were exposed from blastula through larval stage (96 h postfertilization [hpf]) to 0.3, 0.6, 1.25, 2.5, 5 mg/l (1, 2, 4, 8, 16 µM) THC or 0.07, 0.1, 0.3, 0.6, 1.25 mg/l CBD (0.25, 0.5, 1, 2, 4 µM). Despite the similarity in THC and CBD dysmorphologies, ie, edemas, curved axis, eye/snout/jaw/trunk/fin deformities, swim bladder distention, and behavioral abnormalities, the LC50 for CBD (0.53 mg/l) was nearly 7 times lower than THC (3.65 mg/l). At 96 hpf, c-fos, dazl, and vasa were differentially expressed following THC exposure, but only c-fos expression was significantly increased by CBD. Cannabidiol was more bioconcentrated compared with THC despite higher THC water concentrations. This work supports the potential for persistent developmental impacts of cannabinoid exposure, but more studies are needed to assess latent effects and their molecular mechanisms of toxicity.

The immune system is an important target of various xenobiotics, which may lead to severe adverse effects including immunosuppression or inappropriate immunostimulation. Mitochondrial toxicity is one possibility by which xenobiotics exert their toxic effects in cells or organs. In this study, we investigated the impact of three natural compounds, cyclosporine A (CsA), deoxynivalenol (DON) and cannabidiol (CBD) on mitochondrial functions in the THP-1 monocytic cell line. The cells were exposed for 24h to two different concentrations (IC 10 and IC 50 determined by MTT) of each compound. The cells showed concentration-dependent elevated intracellular reactive oxygen species (iROS) and induction of apoptosis (except DON) in response to the three test compounds. Mitochondrial functions were characterized by using bioenergetics profiling experiments. In THP-1 monocytes, the IC 50 of CsA decreased basal and maximal respiration as well as ATP production with an impact on spare capacity indicating a mitochondrial dysfunction. Similar reaction patterns were observed following CBD exposure. The basal respiration level and ATP-production decreased in the THP-1 cells exposed to the IC 50 of DON with no major impact on mitochondrial function. In conclusion, impaired mitochondrial function was accompanied by elevated iROS and apoptosis level in a monocytic cell line exposed to CsA and CBD. Mitochondrial dysfunction may be one explanation for the cytotoxicity of CBD and CsA also in other in immune cells., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Cannabidiol (CBD) is considered a promising neuroprotectant after perinatal hypoxia-ischemia (HI). We have previously studied the effects of CBD 1 mg/kg in the early phase after global HI in piglets. In contrast to prior studies, we found no evidence of neuroprotection and hypothesized that higher doses might be required to demonstrate efficacy in this animal model., Objective: To assess the safety and potential neuroprotective effects of high-dose CBD., Methods: Anesthetized newborn piglets underwent global HI by ventilation with 8% O2 until the point of severe metabolic acidosis (base excess -20 mmol/L) and/or hypotension (mean arterial blood pressure ≤20 mm Hg). Piglets were randomized to intravenous treatment with vehicle (n = 9) or CBD (n = 13). The starting dose, CBD 50 mg/kg, was reduced if adverse effects occurred. The piglets were euthanized 9.5 h after HI and tissue was collected for analysis., Results: CBD 50 mg/kg (n = 4) induced significant hypotension in 2 out of 4 piglets, and 1 out of 4 piglets suffered a fatal cardiac arrest. CBD 25 mg/kg (n = 4) induced significant hypotension in 1 out of 4 piglets, while 10 mg/kg (n = 5) was well tolerated. A significant negative correlation between the plasma concentration of CBD and hypotension during drug infusion was observed (p < 0.005). Neuroprotective effects were evaluated in piglets that did not display significant hypotension (n = 9) and CBD did not alter the degree of neuronal damage as measured by a neuropathology score, levels of the astrocytic marker S100B in CSF, magnetic resonance spectroscopy markers (Lac/NAA and Glu/NAA ratios), or plasma troponin T., Conclusions: High-dose CBD can induce severe hypotension and did not offer neuroprotection in the early phase after global HI in piglets., (© 2017 S. Karger AG, Basel.)

States and the federal government are under growing pressure to legalize the use of cannabis products for medical purposes in the United States. Sixteen states have legalized (or decriminalized possession of) products high in cannabidiol (CBD) and with restricted ∆(9) -tetrahydrocannabinol (∆(9) -THC) content. In most of these states, the intent is for use in refractory epileptic seizures in children, but in a few states, the indications are broader. This review provides an overview of the pharmacology and toxicology of CBD; summarizes some of the regulatory, safety, and cultural issues relevant to the further exploitation of its antiepileptic or other pharmacologic activities; and assesses the current status and prospects for clinical development of CBD and CBD-rich preparations for medical use in the United States. Unlike Δ(9) -THC, CBD elicits its pharmacologic effects without exerting any significant intrinsic activity on the cannabinoid receptors, whose activation results in the psychotropic effects characteristic of Δ(9) -THC, and CBD possesses several pharmacologic activities that give it a high potential for therapeutic use. CBD exhibits neuroprotective, antiepileptic, anxiolytic, antipsychotic, and antiinflammatory properties. In combination with Δ(9) -THC, CBD has received regulatory approvals in several European countries and is currently under study in trials registered by the U.S. Food and Drug Administration in the United States. A number of states have passed legislation to allow for the use of CBD-rich, limited Δ(9) -THC-content preparations of cannabis for certain pathologic conditions. CBD is currently being studied in several clinical trials and is at different stages of clinical development for various medical indications. Judging from clinical findings reported so far, CBD and CBD-enriched preparations have great potential utility, but uncertainties regarding sourcing, long-term safety, abuse potential, and regulatory dilemmas remain., (© 2016 Pharmacotherapy Publications, Inc.)

Cannabidiol (CBD) has been investigated in a wide spectrum of clinical approaches due to its psychopharmacological properties. CBD has low affinity for cannabinoid neuroreceptors and agonistic properties to 5-HT receptors. An interaction between cannabinoid and purinergic receptor systems has been proposed. The purpose of this study is to evaluate CBD properties on memory behavioral and locomotor parameters and the effects of pre-treatment of adenosine receptor blockers on CBD impacts on memory using adult zebrafish. CBD (0.1, 0.5, 5, and 10mg/kg) was tested in the avoidance inhibitory paradigm and anxiety task. We analyzed the effect of a long-term caffeine pre-treatment (~20mg/L - four months). Also, acute block of adenosine receptors was performed in co-administration with CBD exposure in the memory assessment. CBD promoted an inverted U-shaped dose-response curve in the anxiety task; in the memory assessment, CBD in the dose of 5mg/Kg promoted the strongest effects without interfering with social and aggressive behavior. Caffeine treatment was able to prevent CBD (5mg/kg) effects on memory when CBD was given after the training session. CBD effects on memory were partially prevented by co-treatment with a specific A2A adenosine receptor antagonist when given prior to or after the training session, while CBD effects after the training session were fully prevented by adenosine A1 receptor antagonist. These results indicated that zebrafish have responses to CBD anxiolytic properties that are comparable to other animal models, and high doses changed memory retention in a way dependent on adenosine., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: Drugs of abuse affect pregnancy outcomes, however, the mechanisms in which cannabis exerts its effects are not well understood. The aim of this study was to examine the influence of short-term (1-2 hours) exposure to cannabidiol, a major phytocannabinoid, on human placental breast cancer resistance protein function., Study Design: The in vitro effect of short-term exposure to cannabidoil on breast cancer resistance protein in BeWo and Jar cells (MCF7/P-gp cells were used for comparison) was tested with mitoxantrone uptake, and nicardipine was used as positive control. The ex vivo perfused cotyledon system was used for testing the effect of cannabidoil on glyburide transport across the placenta. Glyburide (200 ng/mL) was introduced to maternal and fetal compartments through a recirculating 2 hour perfusion, and its transplacental transport was tested with (n = 8) or without (n = 8) cannabidoil., Results: (1) Cannabidoil inhibition of breast cancer resistance protein-dependent mitoxantrone efflux was concentration dependent and of a noncell type specific nature (P < .0001); (2) In the cotyledon perfusion assay, the administration of cannabidoil to the maternal perfusion media increased the female/male ratio of glyburide concentrations (1.3 ± 0.1 vs 0.8 ± 0.1 at 120 minutes of perfusion, P < .001)., Conclusion: (1) Placental breast cancer resistance protein function is inhibited following even a short-term exposure to cannabidoil; (2) the ex vivo perfusion assay emphasize this effect by increased placental penetration of glyburide to the fetal compartment; and (3) these findings suggest that marijuana consumption enhances placental barrier permeability to xenobiotics and could endanger the developing fetus. Thus, the safety of drugs that are breast cancer resistance protein substrates is questionable during cannabis consumption by pregnant women., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Background and Objective: Marijuana (Cannabis sativa) use may be associated with gingival enlargement, resembling that caused by phenytoin. Cannabidiol (CBD), a nonpsychotropic Cannabis derivative, is structurally similar to phenytoin. While there are many reports on effects of phenytoin on human gingival fibroblasts, there is no information on effects of Cannabis components on these cells. The objective of this study was to determine effects of CBD on human gingival fibroblast fibrogenic and matrix-degrading activities., Material and Methods: Fibroblasts were incubated with CBD in serum-free medium for 1-6 d. The effect of CBD on cell viability was determined by measuring activity of a mitochondrial enzyme. The fibrogenic molecule transforming growth factor β and the extracellular matrix molecule fibronectin were measured by ELISA. Pro-MMP-1 and total MMP-2 were measured by ELISA. Activity of MMP-2 was determined via a colorimetric assay in which a detection enzyme is activated by active MMP-2. Data were analysed using ANOVA and Scheffe's F procedure for post hoc comparisons., Results: Cannabidiol had little or no significant effect on cell viability. Low CBD concentrations increased transforming growth factor β production by as much as 40% (p < 0.001), while higher concentrations decreased it by as much as 40% (p < 0.0001). Cannabidiol increased fibronectin production by as much as approximately 100% (p < 0.001). Lower CBD concentrations increased MMP production, but the highest concentrations decreased production of both MMPs (p < 0.05) and decreased MMP-2 activity (p < 0.02)., Conclusion: The data suggest that the CBD may promote fibrotic gingival enlargement by increasing gingival fibroblast production of transforming growth factor β and fibronectin, while decreasing MMP production and activity., (© 2011 John Wiley & Sons A/S.)

Rationale: Several pre-clinical and human-based studies have shown that acutely administered cannabidiol (CBD) can produce anxiolytic-like effects, Objectives: The present study investigated the effects of chronic administration of CBD on rat behaviour and on the expression of brain proteins., Methods: Male Lister-hooded rats (150-200 g, n = 8 per group) received daily injections of CBD (10 mg/kg, i.p.) for 14 days. The rats were subjected to two behavioural tests: locomotor activity and conditioned emotional response (CER). The expression of brain-derived neurotrophic factor (BDNF), its receptor tyrosine kinase B (Trk B), extracellular signal-regulated kinases (ERK1/2) and phospho-ERK1/2 and the transcription factor cyclic AMP response element binding protein activation (CREB) and phospho-CREB were determined in brain regions such as the frontal cortex and hippocampus using Western immunoblotting., Results: CBD significantly increased the time spent freezing in the CER test with no effect on locomotor activity. CBD significantly reduced BDNF expression in the hippocampus and frontal cortex with no change in the striatum. In addition, CBD significantly reduced TrkB expression in the hippocampus with a strong trend towards reduction in the striatum but had no effect in the frontal cortex. In the hippocampus, CBD had no effect on ERK1/2 or phospho-ERK2, but in the frontal cortex, CBD significantly reduced phospho-ERK1/2 expression without affecting total ERK., Conclusion: Chronic administration of CBD produced an anxiogenic-like effect in clear opposition to the acute anxiolytic profile previously reported. In addition, CBD decreased the expression of proteins that have been shown to be enhanced by chronic treatment with antidepressant/anxiolytic drugs.

There is a high comorbidity between cannabis use and schizophrenia. Several factors contribute to this comorbidity: secondary development of addiction, cannabis-related induction of psychosis and shared neurobiological alterations. Meanwhile, there is evidence that cannabis use is associated with an increased risk of schizophrenia. Prospective epidemiological studies have shown that a frequent cannabis use doubles the risk for schizophrenia. Interestingly, schizophrenic patients with comorbid cannabis use often show significantly better performances in neuropsychological tests than patients without cannabis use. This is nevertheless not due to a positive effect of cannabis, but a sign of cannabis-related psychosis induction in subjects with a higher level of function and less cognitive impairment. Whether cannabis use leads to schizophrenia is determined by the individual vulnerability.

Heavy marijuana use has been linked to white matter histological alterations. However, the impact of cannabis constituents on oligodendroglial pathophysiology remains poorly understood. Here, we investigated the in vitro effects of cannabidiol, the main nonpsychoactive marijuana component, on oligodendrocytes. Exposure to cannabidiol induced an intracellular Ca(2+) rise in optic nerve oligodendrocytes that was not primarily mediated by entry from the extracellular space, nor by interactions with ryanodine or IP(3) receptors. Application of the mitochondrial protonophore carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP; 1 μM) completely prevented subsequent cannabidiol-induced Ca(2+) responses. Conversely, the increase in cytosolic Ca(2+) levels elicited by FCCP was reduced after previous exposure to cannabidiol, further suggesting that the mitochondria acts as the source of cannabidiol-evoked Ca(2+) rise in oligodendrocytes. n addition, brief exposure to cannabidiol (100 nM-10 μM) led to a concentration-dependent decrease of oligodendroglial viability that was not prevented by antagonists of CB(1), CB(2), vanilloid, A(2A) or PPARγ receptors, but was instead reduced in the absence of extracellular Ca(2+). The oligodendrotoxic effect of cannabidiol was partially blocked by inhibitors of caspase-3, -8 and -9, PARP-1 and calpains, suggesting the activation of caspase-dependent and -independent death pathways. Cannabidiol also elicited a concentration-dependent alteration of mitochondrial membrane potential, and an increase in reactive oxygen species (ROS) that was reduced in the absence of extracellular Ca(2+). Finally, cannabidiol-induced cytotoxicity was partially prevented by the ROS scavenger trolox. Together, these results suggest that cannabidiol causes intracellular Ca(2+) dysregulation which can lead to oligodendrocytes demise.

Cannabidiol, the major nonpsychotropic phytocannabinoid, has been recently demonstrated to induce apoptosis in primary lymphocytes via an oxidative stress-dependent mechanism. Cannabidiol can be converted by microsomal enzymes to the hydroxyquinone metabolite HU-331 that forms adducts with glutathione. The present study tested the hypothesis that HU-331 could cause apoptosis via the depletion of thiols in splenocytes. Our results showed that HU-331 treatment significantly enhanced splenocyte apoptosis in a time- and concentration-dependent manner. Concordantly, a gradual diminishment in the cellular thiols and glutathione was detected in HU-331-treated splenocytes. The apoptosis and thiol diminishment induced by HU-331 were abrogated in the presence of thiol antioxidants, including N-acetyl-(L)-cysteine and N-(2-mercaptopropionyl) glycine, whereas the non-thiol antioxidants catalase and pyruvate were ineffective. In comparison, both thiol and non-thiol antioxidants were capable of attenuating H(2)O(2)-induced thiol diminishment and reactive oxygen species generation in splenocytes. Collectively, these results suggest that HU-331 might be an active metabolite of cannabidiol potentially contributing to the induction of apoptosis in splenocytes, and that the apoptosis is primarily mediated by the loss of cellular thiols., (Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.)

Cannabidiol (CBD) is the main non-psychotropic component of the glandular hairs of Cannabis sativa. It displays a plethora of actions including anticonvulsive, sedative, hypnotic, antipsychotic, antiinflammatory and neuroprotective properties. However, it is well established that CBD produces its biological effects without exerting significant intrinsic activity upon cannabinoid receptors. For this reason, CBD lacks the unwanted psychotropic effects characteristic of marijuana derivatives, so representing one of the bioactive constituents of Cannabis sativa with the highest potential for therapeutic use.The present review reports the pharmacological profile of CBD and summarizes results from preclinical and clinical studies utilizing CBD, alone or in combination with other phytocannabinoids, for the treatment of a number of CNS disorders.

This review describes recent advances in the metabolism of cannabinoids. Cannabidiol was metabolized to cannabielsoin, 6 beta-hydroxymethyl-delta 9-tetrahydrocannabinol and an oxepine derivative through epoxide intermediates by hepatic microsomal enzymes containing cytochrome P450 of animals. Cannabidiol inactivated cytochrome P450 UT-2 (CYP2C11) not equal to in male rats and a member of 3A subfamily in mouse liver. These inactivations may be very important because serious drug-drug interactions will occur in the case that cannabidiol is co-administered with drugs which are metabolized mainly by the enzyme system containing these P450 isozymes. A member of cytochrome P450 belonging to 2C subfamily was the major isozymes responsible for the cannabinoid metabolism in many experimental animals and that of 3A subfamily made some contribution to the metabolism of cannabinoids by human hepatic microsomes. Microsomal aldehyde oxygenase, a particular isozyme of cytochrome P450 catalyzing the oxidation of 11-oxo-tetrahydrocannabinol to tetrahydrocannabinol-11-oic acid, was found for the first time by the authors. Cytochrome P450 MUT-2 (CYP2C29) is the major isozyme responsible for the microsomal aldehyde oxygenase activity in mouse hepatic microsomes.

Cannabielsoin (CBE) was identified as a novel metabolite of cannabidiol (CBD) in the guinea pig in vivo and in vitro. Its formation by liver microsomes of guinea pigs needed NADPH and molecular oxygen, and was inhibited with SKF 525-A, metyrapone and alpha-naphthoflavone, indicating participation of cytochrome P-450 (P-450). The CBE-forming activity was highest in guinea pigs, followed by mice, rabbits and rats. In the rat, sex difference was found in the CBE formation (male greater than female). CBD monomethylether (CBDM) was also biotransformed to CBE monomethylether (CBEM) in the guinea pig in vivo and in vitro. When CBD dimethylether (CBDD) was employed as substrate, 1S,2R-epoxy-CBDD was identified. The results suggest that CBD and CBDM are biotransformed by P-450 to CBE-type metabolites via 1S,2R-epoxides. In pharmacological studies using mice, CBDD and 1S,2R-epoxy-CBD-2',6'-diacetate produced hypothermia, and CBD, CBDM and CBEM prolonged pentobarbital-induced sleep. Moreover, 1S,2R-epoxy-CBD-2',6'-diacetate was examined in the Ames test, but had no mutagenicity.

The synthesis of a variety of novel 10-substituted cannabidiol (CBD) and 11- or 12-substituted delta 8-tetrahydrocannabinol (delta 8-THC) analogues containing amino, alkylamino, azido, or a N,N-bis(2-chloroethyl)amino functional group is described, as well as their pharmacological evaluation in mice. These analogues, which possess only a portion of the full pharmacological spectrum of activity of delta 9-THC, indicate that cannabinoid-mediated reduction of spontaneous locomotor activity, hypothermia, antinociception, and/or catalepsy need not be produced simultaneously, possibly suggesting the existence of more than one mechanism of action. The 10-substituted CBD analogues 3, 4, and 5 with an ethylamino, propylamino, or azido functional group, respectively, proved to be largely inactive, except for the production of central nervous system (CNS) depression concomitant with toxicity. Toxicity and CNS depression may be related phenomena in these nitrogenous compounds since 12-amino and 12-ethylamino analogues (8 and 11) of delta 8-THC also proved to be very toxic. Antinociceptive and hypothermic responses (without reduction of motor activity) were observed at a dose of 10 mg/kg of the 11-ethylamino analogue (9) of delta 8-THC, while a dose of 50 mg/kg of the nitrogen mustard 11-[N,N-bis(2-chloroethyl)amino]-delta 8-THC (12) was necessary to produce any observable pharmacological effect. When selected analogues were evaluated for antagonistic properties, they failed to attenuate the effects of delta 9-THC. Some nitrogen mustard analogues were capable of producing minimal pharmacological effects after either peripheral or direct CNS administration; however, these analogues also failed to attenuate the effects of delta 9-THC either immediately after administration or 24-48 h later.

The cytogenetic effects of subacute oral administration of delta-9-tetrahydrocannabinol, cannabidiol, cannabinol, and placebo were assessed in 27 subjects in a prospective double-blind study. Both conventional chromosome aberration analysis and sister chromatid exchange were considered. A comparison group of 5 nondrug users was also investigated. The aneuploidy frequency decreased significantly following delta-9-tetrahydrocannabinol administration. By contrast, the frequencies of chromosome aberrations increased slightly for all three drug groups and decreased in the placebo and comparison groups although none of the predrug versus postdrug comparisons were statistically significant. No increase in the sister chromatid exchange frequency was found in any of the groups when predrug versus postdrug comparisons were made. The present study is the fourth short term prospective investigation failing to demonstrate a statistically significant increase in chromosome damage due to cannabinoid usage. However, it must be kept in mind that to date only gross chromosomal aberrations have been identified so that the more subtle chromosomal as well as molecular genetic damage has not been ruled out.

Maternal exposure to cannabinoids influenced spermatogenesis and fertility in their male offspring examined at 60-80 days of age. Approximately 20% less spermatozoa were found in males whose mothers had received either the non-psychoactive cannabinol (CBN) or cannabidiol (CBD) on day 1 postpartum. Males exposed to the major psychoactive component of marihuana, delta 9-tetrahydrocannabinol (THC) appeared to have spermatozoa in number comparable to controls. This finding may be consistent with the additional observation that CBN or CBD, but not THC, reduced the percentage of successful impregnations by cannabinoid-exposed males. However, males exposed to each of these cannabinoids produced significantly less live offspring compared to controls. Plasma levels of testosterone and luteinizing hormone (LH) were reduced significantly in mice exposed to THC on day 12 of gestation, while testicular weight was reduced in adult mice exposed either on day 12 of gestation to CBD or on day 1 post-partum to THC. These results indicate that perinatal exposure to psychoactive and non-psychoactive components of marihuana can produce long-term disruption of testicular function including the spermatogenic as well as the steroidogenic components.

Maternal exposure to the major psychoactive delta 9-tetrahydrocannabinol (THC), or to the nonpsychoactive cannabinol (CBN) or cannabidiol (CBD) on day 12 of gestation, or on day 1 postpartum, affected the concentrations of hepatic cytochromes P-450 in adult male offspring. Levels of P-450 were significantly increased in adult males prenatally exposed to cannabinoids, but were reduced after postnatal exposure. The response to exogenous testosterone was also differentially affected by perinatal cannabinoid exposure, with reduced plasma androgen in males prenatally exposed to THC, but increased levels of hormone in mice exposed postnatally to THC or CBN. There was a concomitant decrease in plasma albumin and increased gamma-globulin in adult males postnatally exposed to CBN. Beta-globulin levels were also significantly increased in adult males exposed to cannabichromene (CBC) on day 1 postpartum. Cannabinoid exposure during perinatal periods of development exert effects on hepatic function, plasma androgen levels, and on the immune system. These effects may reflect the ability of perinatal cannabinoid exposure to interfere with androgen-mediated processes of differentiation.

The mechanisms of the anticonvulsant activity of cannabidiol (CBD) and the central excitation of delta 9-tetrahydrocannabinol (delta 9-THC) were investigated electrophysiologically with conscious, unrestrained cobalt epileptic rats. The well-known antiepileptics, trimethadione (TMO), ethosuximide (ESM), and phenytoin (PHT), were included as reference drugs. Direct measurements were made of spontaneously firing, epileptic potentials from a primary focus on the parietal cortex and convulsions were monitored visually. ESM and TMO decreased the frequency of focal potentials, but PHT and CBD exerted no such effect. Although CBD did not suppress the focal abnormality, it did abolish jaw and limb clonus; in contrast, delta 9-THC markedly increased the frequency of focal potentials, evoked generalized bursts of polyspikes, and produced frank convlusions. 11-OH-delta 9-THC, the major metabolite of delta 9-THC, displayed only one of the excitatory properties of the parent compound: production of bursts of polyspikes. In contrast to delta 9-THC and its 11-OH metabolite, CBD, even in very high doses, did not induce any excitatory effects or convulsions. The present study provides the first evidence that CBD exerts anticonvulsant activity against the motor manifestations of a focal epilepsy, and that the mechanism of the effect may involve a depression of seizure generation or spread in the CNS.

Maternal exposure to delta 9-tetrahydrocannabinol (THC), the major psychoactive constituent in marihuana, or to the non-psychoactive cannabinol (CBN) or cannabidiol (CBD) alters endocrine functions and concentrations of brain biogenic amines in their male offspring. Prenatal CBN exposure on day 18 of gestation resulted in decreased plasma FSH levels, testicular testosterone (T) concentrations, and seminal vesicles weights, but increased plasma levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) post-castration in adulthood. Prenatal exposure to THC significantly enhanced the responsiveness of the testes to intratesticular LH injection in vivo and tended to increase human chorionic gonadotropin (hCG)-stimulated T production by decapsulated testes in vitro. In the CBN-exposed mice, hCG-stimulated T production was enhanced, while CBD exposure had no effect. Prenatal THC exposure altered the negative feedback effects of exogenous gonadal steroids in castrated adults, with lower plasma T and FSH levels after 20 micrograms T than in castrated controls. In contrast, CBD-exposed mice had higher levels of LH in plasma post-castration. In CBN-exposed adults, two weeks post-castration the concentration of norepinephrine (NE) and dopamine (DA) in hypothalamus and remaining brain were reduced, while levels of serotonin (5-HT) and its metabolite, 5-HIAA, were elevated compared to that in castrated OIL-controls. Prenatal CBD-exposure also reduced NE and elevated 5-HT and 5-HIAA, but did not affect DA levels post-castration. Concentrations of brain biogenic amines were not influenced by prenatal THC exposure in the present study. A single prenatal exposure to psychoactive or non-psychoactive components of marihuana results in long term alterations in the function of the hypothalamo-pituitary-gonadal axis. Changes in the concentrations of brain biogenic amines may be related to these effects of prenatal cannabinoids on endocrine function in adult male mice.

Sperm morphology was studied in hybrid mice of genotype (C57BL X C3H)F1 following treatment with specific cannabinoids. Mice were treated for 5 consecutive days with the specific cannabinoid; 35 days after the last treatment, epididymal sperm were scored in the light microscope and assessed in the scanning electron microscope. The animals treated with delta9-tetrahydrocannabinol (delta9-THC) and cannabinol (CBN) had a statistically higher incidence of abnormal sperm than the controls. The incidence of abnormal sperm in the animals treated with cannabidiol (CBD) was not statistically different from the control value. The relative toxicity of the cannabinoids in these studies was delta9-THC greater than CBN greater than CBD. Normal sperm have a smooth kidney-shaped head with a prominent hook; abnormal sperm have shapes which include heads without hooks, banana-shaped heads, amorphous heads and folded heads.

A Langendorff perfused rat heart preparation was designed to process dose-response effects of cardioactive drugs on rate, coronary flow, and supraaortic differential pressure (delta P; an index of cardiac performance). In this preparation, delta 9- -tetrahydrocannabinol (THC) 2 X 10(-6) M to 10(-5) M induces in the isolated perfused rat heart a biphasic increase in rate (maximal at 8 X 10(-6) M). Tachycardia is associated with decreases in (delta P) and no change or decreased coronary flow. Cardiac toxicity is observed with 3 X 10(-5) M. Cannabidiol (CBD) at concentrations of 9 X 10(-6) M to 10(-4) M has limited effect on rate while increasing delta P and coronary flow. Cannabinol (CBN) 8 X 10(-6) M to 3 X 10(-4) M depresses rate and delta P while coronary flow remains constant. Simultaneous equimolar administration of THC with CBD antagonizes or mitigates the cardiac effects of THC on rate, delta P, and coronary flow.

Maternal exposure to delta 9-tetrahydrocannabinol (THC), the major psychoactive component in marihuana, or to the non-psychoactive cannabinol (CBN) or cannabidiol (CBD) alters male reproductive functions and brain biogenic amines in male and female offspring. Postnatal exposure to THC or CBN reduced body weights, while testicular weights were lower in CBD-exposed mice. Testicular testosterone (T) levels were also lower in CBN- and CBD-exposed animals. Postnatal cannabinoid exposure reduced plasma luteinizing hormone (LH) levels in intact and castrated adults. Although basal T production in vitro was not affected by postnatal cannabinoid exposure, testes from CBD-exposed males were more responsive to gonadotropin stimulation. In contrast, in vivo responsiveness to intratesticular human chorionic gonadotropin (hCG) administration was significantly reduced in THC- and CBD-exposed males. Pituitary weights and their basal LH production in vitro was higher in THC- or CBN-exposed mice. Pituitaries from cannabinoid-exposed males were less responsive to LH releasing hormone (RH) stimulation, however, hypothalamic LHRH content was significantly higher in the THC-exposed males. Hypothalamic dopamine (DA) levels were significantly lower in CBN-exposed castrated mice, compared to castrated controls. The reduction in hypothalmic norepinephrine (NE) in THC- and CBN-exposed castrates after alpha-methylparatyrosine (alpha-MPT) was significantly less than that observed in control castrates. Hypothalamic DA levels were depleted to a greater extent in CBD-exposed males. Brain levels of serotonin (5-HT) and 5-HIAA were significantly higher in castrated, than in intact THC-exposed males. In ovariectomized CBN-exposed females, hypothalamic NE levels were lower, while the alpha-MPT-induced depletion of NE was less in CBD-exposed, compared to control females. Levels of 5-HT were lower only in THC-exposed females. Plasma levels of LH were significantly higher in CBN-exposed, while plasma levels of FSH were reduced in THC- and CBD females. Maternal exposure to psychoactive or non-psychoactive cannabinoids on the day of parturition results in long term alterations in neuroendocrine function in male and female offspring. It is possible that the observed alterations in biogenic amines may mediate the effects of cannabinoids on pituitary and gonadal function.

Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have antagonistic effects on the isolated perfused heart in a Langendorff preparation. THC in concentration of 2 X 10(-6) to 10(-5)M induces an increased frequency with a maximum at 8 X 10(-6)M, and at the same time a decrease in contractile force and coronary flow. CBD at similar concentrations does not affect heart rate, while increasing contractile force and coronary flow. These effects of CBD prevail when this cannabinoid is administered simultaneously with THC.

Marihuana extract containing 21.3% delta-9-tetrahydrocannabinol (100 micrograms/hr), delta-9-tetrahydrocannabinol (20 micrograms/hr), cannabidiol (20 micrograms/hr), or the polyethylene glycol vehicle (1 microliter/hr) was delivered topically to cat eyes via osmotic minipumps over a 9-day period. Intraocular pressure differences between treated and untreated eyes of cats receiving marihuana extract remained 3-4 mmHg lower than those for vehicle controls, while differential values for the delta 9-THC-treated group remained reduced by 3-5 mmHg; data for these two groups did not differ statistically. Pressure differences between treated and untreated eyes of cats receiving cannabidiol were likewise 3-4 mmHg lower than values for controls. Ocular toxicity after delta 9-THC, consisting of conjunctival erythema and chemosis as well as corneal opacification, was quite severe. Although these changes also occurred after marihuana extract, their intensity was much reduced. In contrast, no ocular toxicity became apparent during administration of cannabidiol. While marihuana extract and delta 9-THC produced a dose-related increase in the appearance of 8-13 Hz polyspike discharges in the electrocorticograms of rats, both polyethylene glycol and cannabidiol lacked this effect. These results indicate that the ocular and central effects of marihuana extract and delta 9-THC are qualitatively similar. In addition, it appears that the ocular hypotensive effect produced by cannabidiol is relatively dissociable from both the ocular toxicity and the neurotoxicity associated with marihuana extract.

The effects of cannabidiol (CBD) on electrically evoked kindled seizures were studied in conscious, unrestrained rats with chronically implanted cortical and limbic electrodes, and the results were compared with those of delta 9-tetrahydrocannabinol (delta 9-THC), phenytoin (PHT), and ethosuximide (ESM). All drugs were anticonvulsant, but there were marked differences in their effects on afterdischarge (AD) threshold, duration, and amplitude. CBD, like PHT and delta 9-THC, elevated the AD threshold; in contrast, ESM decreased the threshold but suppressed AD spread. CBD, however, also resembled ESM inasmuch as both drugs decreased AD duration and amplitude. Electrophysiologically, the antiseizure effects of CBD were a combination of those of PHT and ESM. The combination of effects may account for the observation that CBD was the most efficacious of the drugs tested against limbic ADs and convulsions. Other properties of CBD were also noted: For example, compared with delta 9-THC, it is a much more selective anticonvulsant vis-à-vis motor toxicity. CBD also lacks the CNS excitatory effects produced by delta 9-THC, PHT, and ESM. These characteristics, combined with its apparently unique set of electrophysiological properties, support the suggestion that CBD has therapeutic potential as an antiepileptic.