Unraveling the molecular basis of cannabidiolic acid methyl Ester's anti-depressive effects in a rat model of treatment-resistant depression

Major depressive disorder (MDD) stands as a significant cause of disability globally. Cannabidiolic Acid-Methyl Ester (CBDA-ME) (EPM-301, HU-580), a derivative of Cannabidiol, demonstrates immediate antidepressant-like effects, yet it has undergone only minimal evaluation in psychopharmacology. Our goal was to investigate the behavioral and potential molecular mechanisms associated with the chronic oral administration of this compound in the Wistar Kyoto (WKY) genetic model of treatment-resistant depression. Male WKY rats were subjected to behavioral assessments before and after receiving chronic (14-day) oral doses of CBDA-ME (0.5 mg/kg), 15 mg/kg of imipramine or vehicle. At the end of the study, plasma corticosterone levels and mRNA expression of various genes in the medial Prefrontal Cortex and Hippocampus were measured. Behavioral outcomes from CBDA-ME treatment indicated an antidepressant-like effect similar to imipramine, as oral ingestion reduced immobility and increased swimming duration in the Forced Swim Test. Neither treatment influenced locomotion in the Open Field Test nor preference in the Saccharin Preference Test. The behavioral impact in WKY rats coincided with reduced corticosterone serum levels, upregulated mRNA expression of Cannabinoid receptor 1, Fatty Acid Amide Hydrolase, and Corticotropin-Releasing Hormone Receptor 1, alongside downregulation of the Serotonin Transporter in the hippocampus. Additionally, there was an upregulation of CB1 mRNA expression and downregulation of Brain-Derived Neurotrophic Factor in the mPFC. These findings contribute to our limited understanding of the antidepressant effects of CBDA-ME and shed light on its potential psychopharmacological mechanisms. This discovery opens up possibilities for utilizing cannabinoids in the treatment of major depressive disorder and related conditions.

Acute oral cannabidiolic acid methyl ester reduces depression-like behavior in two genetic animal models of depression

BACKGROUND AND PURPOSE

Cannabidiolic acid methyl ester (HU-580) was recently shown to reduce stress-induced anxiety-like behavior in rats. The aim of this study was to examine the antidepressant effect of HU-580 in two different rat models of depression.

EXPERIMENTAL APPROACH

Using the forced swim test (FST), we evaluated the effect of HU-580 in 43 Wistar-Kyoto (WKY) and 23 Flinders Sensitive Line (FSL) adult male rats.

KEY RESULTS

1 mg/kg HU-580 reduced immobility and increased swimming in WKY rats, compared to vehicle-treated controls (p < 0.05). This dose exerted similar effects in FSL rats (p < 0.05).

CONCLUSION AND IMPLICATIONS

This is the first report of antidepressant efficacy of HU-580. These findings expand the very limited existent results, suggesting that HU-580 is a potent anxiolytic agent. Taken together with its chemical stability, HU-580 emerges as a candidate for a future antidepressant medication.