Antioxidative activity of geranium (Pelargonium inquinans Ait) and its active component, 1,2,3,4,6-penta-O-galloyl-beta-D-glucose.

The antioxidative activity of geranium (Pelargonium inquinans Ait) and its active component was investigated under in vitro and cellular oxidative stress models. The MeOH extract, and n-hexane, EtOAc, BuOH and H(2)O fractions from geranium showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effects and protective potential from oxidative damage by the radical generator, 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in renal epithelial LLC-PK(1) cells. In particular, the EtOAc fraction exerted the strongest antioxidative potential in not only the in vitro but also in the cellular system. It suggests that the antioxidative activity of geranium is attributed mainly to components from the EtOAc fraction. Furthermore, the active component, 1,2,3,4,6-penta-O-galloyl-beta-d-glucose (PGG), was identified from the EtOAc fraction by the bioassay-linked fractionation method. It displayed a potent antioxidant effect against the DPPH radical, showing an IC(50) value of 1.14 microg/mL. Moreover, the compound recovered the cell viability declined by AAPH treatment significantly and dose-dependently, implying a protective role against cellular oxidative damage. The present study suggests that geranium has an excellent antioxidative potential and that PGG from geranium is considered to be the active component with an antioxidative effect. (c) 2008 John Wiley & Sons, Ltd.