Social Factors and Animal Models of Cannabis Use

Effects of endocannabinoid system modulation on social behaviour: A systematic review of animal studies

There is a clear link between psychiatric disorders and social behaviour, and evidence suggests the involvement of the endocannabinoid system (ECS). A systematic review of preclinical literature was conducted using MEDLINE (PubMed) and PsychINFO databases to examine whether pharmacological and/or genetic manipulations of the ECS alter social behaviours in wildtype (WT) animals or models of social impairment (SIM). Eighty studies were included. Risk of bias (RoB) was assessed using SYRCLE's RoB tool. While some variability was evident, studies most consistently found that direct cannabinoid receptor (CBR) agonism decreased social behaviours in WT animals, while indirect CBR activation via enzyme inhibition or gene-knockout increased social behaviours. Direct and, more consistently, indirect CBR activation reversed social deficits in SIM. These CBR-mediated effects were often sex- and developmental-phase-dependent and blocked by CBR antagonism. Overall, ECS enzyme inhibition may improve social behaviour in SIM, suggesting the potential usefulness of ECS enzyme inhibition as a therapeutic approach for social deficits. Future research should endeavour to elucidate ECS status in neuropsychiatric disorders characterized by social deficits.

Prosocial Effects of Nonpsychotropic Cannabis sativa in Mice

Introduction:Cannabis sativa L. (C. sativa) is used since ancient times to produce fabrics, baskets, and cords. Later, different ethnic groups used to burn the leaves and flowers of psychotropic cultivars with high Δ9-tetrahydrocannabinol (D9-THC) levels, during the religious or propitiatory rites to alter the state of consciousness. To date, it is not known whether also nonpsychotropic cultivars of C. sativa were used during these rites, and whether these varieties could have an effect on human behavior. This study aimed to evaluate the behavioral effects of an extract of nonpsychotropic C. sativa (NP-CS) in mice. Materials and Methods: An extract of a nonpsychotropic cultivar of C. sativa dissolved in medium-chain triglyceride oil was used and the different phytochemical components were evaluated. The relative composition in terms of phytocannabinoid content was assessed by reverse phase high-performance liquid chromatography coupled to UV detection (RP-HPLC-UV), and the volatile components were analyzed by gas chromatography-mass spectrometry (GC-MS). In addition, the behavioral effect of NP-CS was assessed on a wild-type mouse model. The animals were treated for 14 days (oral gavage) and motility, anxiety, and social effects were assessed. Results: RP-HPLC-UV analysis demonstrated that D9-THC was present in lower concentration with respect to other cannabinoids, like cannabidiol. Furthermore, the GC-MS analysis revealed the presence of several terpenoids. Concerning in vivo studies, chronic treatment with NP-CS did not alter body weight, motility, and anxiety and increased social interaction. Conclusions: This study highlighted the prosocial effects of NP-CS.

A pharmacological characterization of Cannabis sativa chemovar extracts

Background

Cannabis contains Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and cannabidiol (CBD) as the primary constituents responsible for pharmacological activity. However, there are numerous additional chemically-related structures to Δ⁹–THC and CBD that are pharmacologically active and may influence the pharmacological properties of Δ⁹-THC and CBD. This study chemically characterized the cannabinoid constituents in a series of cannabis chemovar extracts and investigated the potential cannabinoid entourage effect in two behavioral assays.

Methods

Six chemovar extracts were compared to pure Δ⁹-THC, CBD and morphine for effects on the following behavioral assays in mice: hot plate and tail suspension. The battery of behavioral tests was conducted post intravenous administration of cannabis chemovar extract. Cannabinoid profiles of extracts were analyzed using high performance liquid chromatography. Cannabis extracts were administered at equal doses of Δ⁹-THC to investigate the role of their cannabinoid profiles in modulating the effects of Δ⁹-THC. Dose response curves were fit using a log[inhibitor] vs response three parameter model and differences between group means were determined using a one-way ANOVA followed by a post hoc test.

Results

Cannabis chemovars tested in this study exhibited substantially different cannabinoid profiles. All chemovars produced dose-dependent immobility in the tail suspension assay and dose-dependent antinociception in the hot plate assay. The maximum antinociceptive effect and ED50 was comparable between cannabis chemovars and Δ⁹-THC. Two cannabis chemovars produced significantly greater immobility in the tail suspension test, with no significant differences in ED50.

Conclusions

Commercially available cannabis chemovars vary widely in cannabinoid content, but when equalized for Δ⁹-THC content, they produce similar behavioral effects with two exceptions. These findings provide only limited support for the entourage hypothesis. Further studies are necessary to characterize the nature of these pharmacological differences between cannabis chemovars and pure Δ⁹-THC.

Herbs and Spices in the Treatment of Functional Gastrointestinal Disorders: A Review of Clinical Trials

More than fifty percent of all new patient visits to pediatric gastroenterology clinics consult for functional abdominal pain disorders (FAPDs). In 2005, a technical report of the American Academy of Pediatrics and the North American Pediatric Gastroenterology, Hepatology and Nutrition society (NASPGHAN) found limited or inconclusive evidence for most therapeutic interventions for this group of disorders. The report did not include studies on herbs and spices. Since then, there has been an increasing interest in the use of complementary and alternative medicine (CAM) for the treatment of chronic pain disorders in children. About 40% of parents of pediatric gastroenterology patients have utilized CAM. This review evaluated the published literature on the effectiveness of CAM, specifically the use of herbs and spices, for the treatment of FAPDs. We found little evidence for most of the commonly used herbs and spices. Despite its common use, research on the efficacy, safety, and optimal dosage remains limited. There is evidence to suggest the benefit of peppermint oil and STW 5 for the treatment of FAPDs in children. The paucity of data on most therapies underscores the need for large clinical trials to assess their efficacy.