Anti-apoptotic effects of novel phenolic antioxidant isolated from the Pacific oyster (Crassostrea gigas) on cultured human hepatocytes under oxidative stress

The antioxidant, and hepatoprotective properties of 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), a natural phenolic antioxidant isolated from the Pacific oyster, were defined using cultured human hepatocyte-derived cells (C3A). DHMBA showed no cytotoxicity at 62.5-500 mu M, as well as chlorogenic acid (CGA), vitamin C, and vitamin E. However, butylated hydroxytoluene, eicosapentaenoic acid, docosahexaenoic acid and catechin reduced cell viability. In the presence of the prooxidant 2,2'-azobis(2-amidino-propane) dihydrochloride (AAPH), DHMBA at 125-500 mu M improved cell viability, whereas CGA had no effect. DNA ladder formation and flow-cytometric studies indicated that DHMBA inhibited MPH-induced apoptosis and necrosis. CGA was ineffective. Thus, DHMBA is a novel, potent antioxidant, effectively protecting cultured hepatocytes from apoptosis and necrosis caused by oxidative stress. Additionally, the concentration of DHMBA was determined by mass spectrometry to be 24.4 mu mol/kg wet oyster meat, and three polyphenols (gentisic acid, daidzein, and matairesinol) were newly identified in the oyster extracts. (C) 2014 Elsevier Ltd. All rights reserved.