A phenolic antioxidant from the Pacific oyster (Crassostrea gigas) inhibits oxidation of cultured human hepatocytes mediated by diphenyl-1-pyrenylphosphine

3,5-Dihydroxy-4-methoxybenzyl alcohol (DHMBA), an antioxidant isolated from the Pacific oyster (Crassostrea gigas), was studied in a cell-based fluorometric antioxidant assay using human hepatocyte-derived cells (C3A) and diphenyl-1-pyrenylphosphine (DPPP) as a fluorescent probe. In comparison with two hydrophilic antioxidants. DHMBA showed the stronger inhibition of DPPP-mediated fluorescence than chlorogenic acid and L-ascorbic acid: at a concentration of 320 mu M of DPPP, the inhibition was 26.4 +/- 2.6%, 11.1 +/- 1.2%, and 0 +/- 2.0% for DHMBA, chlorogenic acid, and L-ascorbic acid, respectively (mean +/- SD, n = 4). Their relative oxygen radical absorbance capacities (ORAC) were dissociated with their cell-based antioxidant activities: 1.47 +/- 0.40, 4.57 +/- 0.30, and 0.53 +/- 0.13 mu mol TE/mu mol for DHMBA, chlorogenic acid, and L-ascorbic acid, respectively (mean +/- SD, n = 4). The amphiphilicity of DHMBA was better than chlorogenic acid and L-ascorbic acid might underlie this dissociation. Since the C3A cells are human hepatoma-derived cells, DHMBA might be useful in the prevention and treatment of liver diseases by involving an oxidation process. (C) 2012 Elsevier Ltd. All rights reserved.