DLPC attenuates alcohol-induced cytotoxicity in HepG2 cells expressing CYP2E1

Abstract

Aims: Alcoholic liver injury was shown to result largely from oxidative stress generated by ethanol metabolism via cytochrome P4502E1 (CYP2E1). Our aim was to determine whether this could be overcome by using dilinoleoylphosphatidylcholine (DLPC), an innocuous antioxidant extracted from soybeans. Methods: To address this question, we determined whether DLPC protects against alcohol-induced cytotoxicity in HepG2 cells expressing CYP2E1. A HepG2 subclone (2E1) expressing CYP2E1 and a control subclone (Neo) were exposed for 2 h to DLPC (10 μM), and then 100 mM ethanol was added for 5 days. Results: Ethanol significantly decreased cell viability in the 2E1 cells and increased apoptosis. These alterations were attenuated by DLPC with the most significant effects in the 2E1 cells. This was accompanied by a reduction of the ethanol-induced oxidative stress, including diminished hydrogen peroxide production in the 2E1, but not in the Neo cells. The mitochondrial membrane potential was significantly diminished by ethanol in both cells. It was also improved after adding DLPC, but only in the 2E1 cells. In these cells, mitochondrial glutathione (GSH) was also partially restored by DLPC, which significantly inhibited the CYP2E1 induction by ethanol. Conclusion: DLPC opposes the cytotoxicity induced by alcohol in HepG2 cells expressing CYP2E1, a protective action due, at least in part, to an attenuation of the alcohol-induced oxidative stress and the alteration in the mitochondrial membrane potential. On account of these beneficial effects of DLPC and its innocuity, it is now germane to assess its therapeutic action in alcoholics. © The Author 2005. Published by Oxford University Press on behalf of the Medical Council on Alcohol. All rights reserved.