The role of hepatic cytochrome P450s in the cytotoxicity of dronedarone

Abstract

Dronedarone is used to treat patients with cardiac arrhythmias and has been reported to be associated with liver injury. Our previous mechanistic work demonstrated that DNA damage-induced apoptosis contributes to the cytotoxicity of dronedarone. In this study, we examined further the underlying mechanisms and found that after a 24-h treatment of HepG2 cells, dronedarone caused cytotoxicity, G1-phase cell cycle arrest, suppression of topoisomerase II, and DNA damage in a concentration-dependent manner. We also investigated the role of cytochrome P450s (CYPs)-mediated metabolism in the dronedarone-induced toxicity using our previously established HepG2 cell lines expressing individually 14 human CYPs (1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 3A4, 3A5, and 3A7). We demonstrated that CYP3A4, 3A5, and 2D6 were the major enzymes that metabolize dronedarone, and that CYP3A7, 2E1, 2C19, 2C18, 1A1, and 2B6 also metabolize dronedarone, but to a lesser extent. Our data showed that the cytotoxicity of dronedarone was decreased in CYP3A4-, 3A5-, or 2D6-overexpressing cells compared to the control HepG2 cells, indicating that the parent dronedarone has higher potency than the metabolites to induce cytotoxicity in these cells. In contrast, cytotoxicity was increased in CYP1A1-overexpressing cells, demonstrating that CYP1A1 exerts an opposite effect in dronedarone's toxicity, comparing to CYP3A4, 3A5, or 2D6. We also studied the involvement of topoisomerase II in dronedarone-induced toxicity, and demonstrated that the overexpression of topoisomerase II caused an increase in cell viability and a decrease in γ-H2A.X induction, suggesting that suppression of topoisomerase II may be one of the mechanisms involved in dronedarone-induced liver toxicity.

Development and Application of TK6-derived Cells Expressing Human Cytochrome P450s for Genotoxicity Testing

“…In addition, some evidence suggests the use of HepG2 cells may result in a reduced sensitivity to genotoxicants in the MN assay (Fowler et al, 2014). Recently, some genetically modified HepG2 cell lines expressing human drug metabolizing genes have been developed and used for assessing drug metabolism-associated toxicity (Chen et al, 2018;Wu et al, 2016;Xuan et al, 2016). Human embryonic kidney cells (HEK293T) have also been engineered to transiently express human CYPs via mRNA transfection (DeGroot et al, 2018).…”

Licorice Ameliorates Cisplatin-Induced Hepatotoxicity Through Antiapoptosis, Antioxidative Stress, Anti-Inflammation, and Acceleration of Metabolism

“…TOP2A was closely related to the proliferation of various cancer cells (Chen et al, 2017;Liu et al, 2018). Overexpression of TOP2A increased hepatocyte viability and participated in drug-induced hepatotoxicity (Chen et al, 2018), and is an important biomarker involved in hepatocyte proliferation during liver regeneration in rats (Bai et al, 2019). The expression of ABCB1B, CYP4A2, CYP1A1, CYP1A2, ESR1, TOP2A, and ABCC2 in CP-induced hepatotoxicity rats can be reversed by GC pretreatment in a dose-dependent manner, which is crucial in the transmembrane transport of drugs and CP hepatotoxicity processes.…”