In Vitro and Cellular Antioxidant Activity of a Water Extract of Saururus chinensis

The water extract of Saururus chinensis was investigated for oxygen radical absorbance capacity (ORAC), reducing capacity, metal chelating activity, and intracellular antioxidant activity using HepG2 cell. When 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) was used for the generation of peroxyl radicals in vitro, S. chinensis extract (SC-E) showed the strong and concentration-dependent scavenging activity through donating protons which could be explained by its reducing property. When hydroxyl radicals were generated in vitro through the addition of $Cu^{2+}$ and $H_2O_2$, SC-E demonstrated the antioxidant activity depending on its concentration. In HepG2 cell model, most of intracellular oxidative stress generated by AAPH was efficiently removed by SC-E. However, when $Cu^{2+}$ without $H_2O_2$ was used as an oxidant in the intracellular assay, SC-E partially reduced the oxidative stress caused by $Cu^{2+}$ in cellular antioxidant activity assay system. These results indicate that SC-E could be utilized for the development of functional foods as antioxidant resource in the near future.