7-Hydroxycannabidiol and 7-carboxycannabidiol induced cytotoxicity via apoptosis and endoplasmic reticulum stress in human hepatic cells.

Cannabidiol (CBD), a major component of extract from the plant Cannabis sativa L., has demonstrated efficacy in treating childhood-onset epilepsy; however, animal studies and clinical trials have reported elevated liver enzymes after CBD use, suggesting potential liver toxicity. In a previous study, we demonstrated that CBD caused cytotoxicity with apoptosis and endoplasmic reticulum (ER) stress in human hepatic cells. In the present study, we investigated the toxicity profile of the two main metabolites of CBD, 7-hydroxy-CBD and 7-carboxy-CBD, in primary human hepatocytes and HepG2 cells. Our findings indicated that both metabolites induced cellular damage similar to the parent drug in these cells. 7-Hydroxy-CBD and 7-carboxy-CBD also caused cell cycle disturbances, apoptosis, and ER stress in HepG2 cells. Additionally, we explored the role of cytochrome P450 (CYP) in the metabolism of 7-hydroxy-CBD and 7-carboxy-CBD using HepG2 cell lines expressing 14 individual CYPs. We determined that 7-hydroxy-CBD is metabolized by CYP2D6, and CYP2D6-mediated metabolism attenuated the cytotoxicity, apoptosis, and ER stress induced by 7-hydroxy-CBD. The CYPs did not metabolize 7-carboxy-CBD. In summary, our findings highlight the mechanisms underlying cytotoxicity induced by 7-hydroxy-CBD and 7-carboxy-CBD in hepatic cells.