Abstract
Inflammation is a natural response of the body to signals of tissue damage or infection caused by pathogens. However, when it becomes imbalanced, it can lead to various disorders such as cancer, obesity, cardiovascular problems, neurological conditions, and diabetes. The endocannabinoid system, which is present throughout the body, plays a regulatory role in different organs and influences functions such as food intake, pain perception, stress response, glucose tolerance, inflammation, cell growth and specialization, and metabolism. Phytocannabinoids derived from Cannabis sativa can interact with this system and affect its functioning. In this study, we investigate the mechanisms underlying the anti-inflammatory effects of three minor phytocannabinoids including tetrahydrocannabivarin (THCV), cannabichromene (CBC), and cannabinol (CBN) using an in vitro system. We pre-treated THP-1 macrophages with different doses of phytocannabinoids or vehicle for one hour, followed by treating the cells with 500 ng/mL of LPS or leaving them untreated for three hours. To induce the second phase of NLRP3 inflammasome activation, LPS-treated cells were further treated with 5 mM ATP for 30 min. Our findings suggest that the mitigation of the PANX1/P2X7 axis plays a significant role in the anti-inflammatory effects of THCV and CBC on NLRP3 inflammasome activation. Additionally, we observed that CBC and THCV could also downregulate the IL-6/TYK-2/STAT-3 pathway. Furthermore, we discovered that CBN may exert its inhibitory impact on the assembly of the NLRP3 inflammasome by reducing PANX1 cleavage. Interestingly, we also found that the elevated ADAR1 transcript responded negatively to THCV and CBC in LPS-macrophages, indicating a potential involvement of ADAR1 in the anti-inflammatory effects of these two phytocannabinoids. THCV and CBN inhibit P-NF-κB, downregulating proinflammatory gene transcription. In summary, THCV, CBC, and CBN exert anti-inflammatory effects by influencing different stages of gene expression: transcription, post-transcriptional regulation, translation, and post-translational regulation.