Cannabis sativa Root Extract Exerts Anti-Nociceptive and Anti-Inflammatory Effects via Endocannabinoid Pathway Modulation In Vivo and In Vitro

Cannabis sativa root has traditionally been used to relieve pain and inflammation, but its pharmacological properties remain underexplored due to low levels of psychoactive cannabinoids. This study aimed to investigate the anti-inflammatory and antinociceptive effects of the ethyl acetate fraction of Cannabis sativa root (CSREA) using in vivo rodent pain models. Mice were subjected to formalin and acetic acid-induced nociceptive tests, while rats were evaluated using a carrageenan-induced paw edema model. CSREA significantly reduced pain-related behaviors in both early (0–10 min) and late phases (15–30 min) of the formalin test and decreased writhing responses in the acetic acid model. Notably, CSREA also improved survival rates following acetic acid injection. Inflammatory markers, including IL-6 and IL-1β, were significantly lowered in serum. Furthermore, CSREA suppressed paw edema and redness in the carrageenan-induced rat model, demonstrating dose-dependent anti-inflammatory efficacy comparable to diclofenac. CSREA also downregulated pain-related gene expression (SCN9A, ASIC1A, TACR1) and regulated key enzymes involved in endocannabinoid metabolism (FAAH, MAGL, DAGL), suggesting its role in the molecular modulation of pain pathways. These effects are likely mediated via modulation of the endocannabinoid system, particularly by rebalancing the CB1R/CB2R ratio. The findings suggest that CSREA holds promise as a natural therapeutic agent for managing pain and inflammation and warrants further investigation into its molecular mechanisms and long-term effects.