FISHERIES RESEARCH INSTITUTE,MOA,TAIWANFISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

In this study, the antioxidative and cytoprotective effect of Sargassum hemiphyllum ethanolic extract against hydrogen peroxide (H₂O₂)-stimulated 3T3-L1 adipocytes was investigated. The amount of total phenolic compounds in S. hemiphyllum ethanolic extract was 22.35 ± 1.41 mg/g dry seaweed. The antioxidative activity of S. hemiphyllum ethanolic extract was evaluated using four different methods, including reducing power, DPPH free radicals scavenging activity, Fe₊₂ chelating activity and SOD-like activity. The results showed that S. hemiphyllum ethanolic extract had the potential DPPH free radicals scavenging and SOD-like activities. The S. hemiphyllum ethanolic extract significantly reduced the intracellular reactive oxygen species (ROS) that produced by H₂O₂ stimulating, and it also raised cell survivability. At 1.5 and 2.0 mg/ml, S. hemiphyllum ethanolic extract increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), and decreased its mRNA expression of gp91^phox and p67^phox of NADPH oxidase subunits. Thus, it is suggested that S. hemiphyllum ethanolic extract increasingly protected 3T3-L1 adipocytes against oxidative damage by the cellular antioxidant activity and inhibited oxidase mRNA expression.