Cannabinoids: Revealing their complexity and role in central networks of fear and anxiety

Phytocannabinoids restore seizure-induced alterations in emotional behaviour in male rats

Epilepsy often presents with severe emotional comorbidities including anxiety and abnormal fear responses which impose a significant burden on, and reduce, quality of life in people living with the disease. Our lab has recently shown that kindled seizures lead to changes in emotional processing resulting from the downregulation of anandamide signalling within the amygdala. Phytocannabinoids derived from the Cannabis sativa plant have attracted a lot of interest as a new class of drugs with potential anticonvulsant effects. Among the wide number of compounds occurring in Cannabis sativa, Δ9- tetrahydrocannabinol (THC), the one responsible for its main psychoactive effects, and the nonpsychoactive cannabidiol (CBD) have been extensively examined under pre-clinical and clinical contexts to control seizures, however, neither have been assessed in the context of the management of emotional comorbidities associated with seizure activity. We used two behavioural procedures to assess anxiety- and fear-like responding in adult male Long-Evans rats: elevated plus maze and auditory fear conditioning. In agreement with previous reports, we found seizure-induced increases in anxiety- and fear-like responding. These effects were reversed by either CBD (vaporized) or THC (oral). We also found that antagonism of serotonin 1 A receptors prior to CBD exposure prevented its protective effects. Phytocannabinoids offer a novel and reliable opportunity to treat seizure induced comorbid emotional alterations.

Identification of Fatty Acids, Amides and Cinnamic Acid Derivatives in Supercritical-CO2 Extracts of Cinnamomum tamala Leaves Using UPLC-Q-TOF-MSE Combined with Chemometrics

Cinnamomum tamala leaf (CTL), also known as Indian bay leaf, is used all over the world for seasoning, flavoring, and medicinal purposes. These characteristics could be explained by the presence of several essential bioactive substances and lipid derivatives. In this work, rapid screening and identification of the chemical compounds in supercritical (SC)-CO2 extracts of CTL by use of UPLC-Q-TOF-MSE with a multivariate statistical analysis approach was established in both negative and positive mode. A total of 166 metabolites, including 66 monocarboxylic fatty acids, 52 dicarboxylic fatty acids, 27 fatty acid amides, and 21 cinnamic acid derivatives, were tentatively identified based on accurate mass and the mass spectrometric fragmentation pattern, out of which 142 compounds were common in all SC-CO2 extracts of CTL. Further, PCA and cluster hierarchical analysis clearly discriminated the chemical profile of analyzed extracts and allowed the selection of SC-CO2 extract rich in fatty acids, fatty acid amides, and other bioactive constituents. The result showed that the higher number of compounds was detected in CTL4 (300 bar/55 °C) extract than the other CTL extracts. The mono- and di-carboxylic fatty acids, fatty acid amides, and cinnamic acid derivatives were identified in CTL for the first time. UPLC-Q-TOF-MSE combined with chemometric analysis is a powerful method to rapidly screen the metabolite profiling to justify the quality of CTL as a flavoring agent and in functional foods.

Endocannabinoid Hydrolase Inhibitors: Potential Novel Anxiolytic Drugs

Over the past decade, the idea of targeting the endocannabinoid system to treat anxiety disorders has received increasing attention. Previous studies focused more on developing cannabinoid receptor agonists or supplementing exogenous cannabinoids, which are prone to various adverse effects due to their strong pharmacological activity and poor receptor selectivity, limiting their application in clinical research. Endocannabinoid hydrolase inhibitors are considered to be the most promising development strategies for the treatment of anxiety disorders. More recent efforts have emphasized that inhibition of two major endogenous cannabinoid hydrolases, monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH), indirectly activates cannabinoid receptors by increasing endogenous cannabinoid levels in the synaptic gap, circumventing receptor desensitization resulting from direct enhancement of endogenous cannabinoid signaling. In this review, we comprehensively summarize the anxiolytic effects of MAGL and FAAH inhibitors and their potential pharmacological mechanisms, highlight reported novel inhibitors or natural products, and provide an outlook on future directions in this field.

Sex-dependent differences in the anxiolytic-like effect of cannabidiol in the elevated plus-maze

RATIONALE

Cannabidiol (CBD), the major non-psychoactive constituent of cannabis, has therapeutic potential for the treatment of anxiety. Most preclinical studies investigate only acute effects of CBD and only in males, yet the drug is most likely to be used over a sustained period in clinical practice.

OBJECTIVES

The objectives of this study were to investigate the anxiolytic-like effect of CBD in female rats compared to males and to determine whether the responsiveness of females was influenced by the stage of the estrous cycle.

METHODS

We carried out experiments to compare the effect of CBD in male and female rats in the elevated plus maze (EPM) in response to acute and short-term (4 days) administration through a complete cycle in females.

RESULTS

Male and female rats behaved in a similar manner in the EPM, but females in the late diestrus (LD) phase exhibited more anxiety-like behavior than at other stages, the difference reaching statistical significance compared to proestrus stages. CBD produced anxiolytic-like effects in both sexes, but female rats were responsive only in LD and 10-fold lower dose than males. After sub-chronic (4 days) treatment, responsiveness to CBD was maintained in females in LD, but females in proestrus remained unresponsive to CBD treatment.

CONCLUSIONS

We suggest that there are sex differences in the anxiolytic-like effects of CBD in rats that reflect different underlying mechanisms: based on literature data, gonadal hormone status linked to GABA_A receptor expression in females, and 5-HT_1A receptor activation in males.

Increased cannabis intake during the COVID-19 pandemic is associated with worsening of depression symptoms in people with PTSD

BACKGROUND

Some evidence suggests substance use affects clinical outcomes in people with posttraumatic stress disorder (PTSD). However, more work is required to examine links between mental health and cannabis use in PTSD during exposure to external stressors such as the COVID-19 pandemic. This study assessed mental health factors in individuals with self-reported PTSD to: (a) determine whether stress, anxiety, and depression symptoms were associated with changes in cannabis consumption across the pandemic, and (b) to contrast the degree to which clinically significant perceived symptom worsening was associated with changes in cannabis intake.

METHOD

Data were obtained as part of a larger web-based population survey from April 3rd to June 24th 2020 (i.e., first wave of the pandemic in Canada). Participants (N = 462) with self-reported PTSD completed questionnaires to assess mental health symptoms and answered questions pertaining to their cannabis intake. Participants were categorized according to whether they were using cannabis or not, and if using, whether their use frequency increased, decreased, or remained unchanged during the pandemic.

RESULTS

Findings indicated an overall perceived worsening of stress, anxiety, and depression symptoms across all groups. A higher-than-expected proportion of individuals who increased their cannabis consumption reached threshold for minimal clinically important worsening of depression, X2(3) = 10.795, p = 0.013 (Cramer's V = 0.166).

CONCLUSION

Overall, those who increased cannabis use during the pandemic were more prone to undergo meaningful perceived worsening of depression symptoms. Prospective investigations will be critical next steps to determine the directionality of the relationship between cannabis and depressive symptoms.

Brain systems in cocaine abstinence-induced anxiety-like behavior in rodents: A review

Cocaine use disorder (CUD) is a significant public health issue that generates substantial personal, familial, and economic burdens. Still, there are no FDA-approved pharmacotherapies for CUD. Cocaine-dependent individuals report anxiety during withdrawal, and alleviation of anxiety and other negative affective states may be critical for maintaining drug abstinence. However, the neurobiological mechanisms underlying abstinence-related anxiety in humans or anxiety-like behavior in rodents are not fully understood. This review summarizes investigations regarding anxiety-like behavior in mice and rats undergoing cocaine abstinence, as assessed using four of the most common anxiety-related assays: the elevated plus (or its derivative, the elevated zero) maze, open field test, light-dark transition test, and defensive burying task. We first summarize available evidence that cocaine abstinence generates anxiety-like behavior that persists throughout protracted abstinence. Then, we examine investigations concerning neuropeptide, neurotransmitter, and neuromodulator systems in cocaine abstinence-induced anxiety-like behavior. Throughout, we discuss how differences in sex, rodent strain, cocaine dose and dosing strategy and abstinence duration interact to generate anxiety-like behavior.

Qualitative and Quantitative Analysis of Six Fatty Acid Amides in 11 Edible Vegetable Oils Using Liquid Chromatography-Mass Spectrometry

Fatty acid amides (FAAs) are endogenous lipid molecules that exhibit various physiological activities. FAAs are usually present at nanomolar levels in biological samples. In this study, a method for the qualitative and quantitative determination of six FAAs (linoleamide, linoleoyl ethanolamide, oleoyl ethanolamide, palmitic amide, oleamide, and octadecanamide) in edible vegetable oils was established. All six FAAs were detected in sesame, peanut, soybean (decolorized and non-decolorized), and blended oils; five in sunflower oil; four in rice oil; three in linseed and olive oils; and two in corn and canola oils. The total contents of FAAs were highest in sesame oil (104.88 ± 3.01 μg/mL), followed by peanut oil (34.96 ± 3.87 μg/mL), soybean oil (16.75 ± 1.27 μg/mL), and blended oil (13.33 ± 0.77 μg/mL), and the contents in the other edible vegetable oils were all <1.03 μg/mL. The concentrations of linoleoyl ethanolamide and oleoyl ethanolamide were highest in non-decolorized soybean oil, while the other four FAAs (linoleamide, palmitic amide, oleamide, and octadecanamide) showed the highest concentrations in sesame oil. The total contents of these FAAs in eight different oils were higher than those in biological fluids and tissue. Our study confirmed that edible vegetable oils are rich in FAAs, and provides reliable data for evaluating the nutritive value of vegetable oils.