Abstract
The aim of this study was to investigate the protective effects of ethanol (EAP) and acidic ethanol extracts (AEAP) of astringent persimmon fruits (Diospyros kaki) against hydrogen peroxide (H(2)O(2))-induced oxidative stress in Caco-2 epithelial cells. Levels of reactive oxygen species (ROS) and reduced glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT), as well as protein and DNA damage were measured. Treatment with H(2)O(2) induced oxidative stress in Caco-2 cells but had no effect on SOD activity. Both EAP and AEAP protected the cells against oxidative damage and exhibited similar effects on cellular ROS scavenging activity and protein carbonyl levels. However, AEAP was more potent than EAP in normalizing CAT activity and cytosolic GSH level, and in protecting against DNA damage. These results demonstrated that astringent persimmon fruit extracts were biologically active, and that the tannin-rich fraction (AEAP) possesses stronger protective activity against H(2)O(2)-induced oxidative stress in Caco-2 cells.