Abstract:The in vitro antioxidant activity and protective effect of Brassica rapa ethanol extracts (BREE) on oxidative damage of Caco-2 cells were investigated. In vitro antioxidant capability of BCEE was evaluated according to the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals(·OH) scavenging ability, and reducing power assay, respectively. Cellular protective effect of BREE was investigated using a model of intestinal epithelial Caco-2 cells induced oxidative stress by hydrogen peroxide (H2O2, 150 μmol/L) of. Cell viability was determined by MTT assay. The intracellular levels of superoxide dismutase (SOD), catalase(CAT) and glutathione peroxidase (GSH-Px) were determined by commercial assay kits according the manuscripts. The intracellular levels of malondiadehycle (MDA) and reactive oxygen specisis (ROS) were determined by thiobarbituric acid reactive substance (TBARS) and dichloro-dihydro-fluorescein diacetate(DCFH-DA) assay, respectively. The levels of interlukin (IL)-1β and IL-8 were determined by enzyme linked immunosorbent assay (ELISA) kits. BREE exhibited a great activity of scavenging DPPH and ·OH radicals, and also showed a strong reducing power. BREE significantly increased the cell viability and activities of SOD, CAT and GSH-Px in cells. In addition, BREE also effectively decreased the intracellular levels of ROS and MDA, and reduced the secretion of IL-1β and IL-8 in Caco-2 cells treated with H2O2 . These results suggested that the BREE exhibited a good in vitro antioxidant activity. BREE treatment could enhance the activities of endogenous antioxidant enzymes, which could attenuate the oxidative damage and reduce the inflammation reaction in Caco-2 cells treated with H2O2.
