Distinct Interactions of Cannabinol and Its Cytochrome P450-Generated Metabolites with Receptors and Sensory Neurons

Interest in nonpsychotropic cannabinoids like cannabinol (CBN) is increasing for pain therapy. This study delivers critical insights into CBN's metabolism and pharmacological effects, uncovering its therapeutic potential for pain reduction. Using metabolomics, we identify CBN-11-OH as the dominant metabolite, with lower levels of CBN-1'-OH and CBN-quinone. Computational simulations reveal CBN's stability at the CYP2C9 active site, driving hydroxy metabolite formation. We report the intricate biotransformation of CBN by multiple cytochrome P450 enzymes. CBN and its metabolites exhibit mild anti-inflammatory effects in microglial cells, though less potent than cannabigerol and cannabichromene. Receptor activation assays further reveal that CBN-1'-OH acts as a partial CB1 agonist, while CBN and its metabolites antagonize CB1 and CB2 receptors. Notably, CBN and CBN-11-OH elevate intracellular Ca²⁺ levels in dorsal root ganglia sensory neurons─an effect linked to potential pain relief. These findings lay the groundwork for harnessing CBN and its metabolites in novel pain therapeutics.