Cannabidiol regulates the expression of hypothalamus-pituitary-adrenal axis-related genes in response to acute restraint stress.

Abstract

Research interest has grown around the potential therapeutic use of cannabidiol in mood-related disorders, due to its anxiolytic and antidepressant-like effects. These have been partially attributed to its action as an allosteric modulator of 5-HTR1A. However, the exact mechanism supporting cannabidiol properties remains unclear. To assess the effects of cannabidiol on different targets of the hypothalamus-pituitary-adrenal axis under baseline and stress conditions. We administered cannabidiol (5 mg/kg, 15 mg/kg or 30 mg/kg, intraperitoneally) or vehicle to male C57BL/6J mice 90 min before single restraint stress exposure (20 min). Using real-time polymerase chain reaction analysis, we measured alterations in the relative gene expression of corticotropin-releasing factor in the paraventricular nucleus, pro-opiomelanocortin in the arcuate nucleus of the hypothalamus, glucocorticoid receptor in the hippocampus, and serotonin 5-HTR1A receptor in the hippocampus and amygdala. Under baseline conditions, cannabidiol did not modify any element of the hypothalamus-pituitary-adrenal axis. In contrast, all doses induced alterations in 5-HTR1A in the amygdala and hippocampus. Interestingly, cannabidiol at low (5 mg/kg) and intermediate doses (15 mg/kg) successfully blocked the effects induced by acute stress on corticotropin-releasing factor, pro-opiomelanocortin and glucocorticoid receptor gene expression. Also, restraint stress induced the opposite effects in 5-HTR1A gene expression in the hippocampus and amygdala, an effect not seen in mice treated with cannabidiol at low doses. Taken together, these data suggest the ability of cannabidiol to regulate acute stress hypothalamus-pituitary-adrenal axis activation might be explained, at least in part, by its action on 5-HTR1A receptors.