Evaluation on Antioxidant Activities of Extracts from Gynostemma pentaphyllum

Three methods,including salicylic acid,DPPH(2,2-diphenyl-1-picrylhydrazyl) and deoxidization Fe3+,were used to evaluate the in vitro antioxidant activities of extracts from Gynostemma pentaphyllum using ethanol,petroleum ether,chloroform,ethyl acetate,n-butanol or water,and Vc was employed as a control.The results showed that with the exception of petroleum ether extract,the extracts had good scavenging activities for hydroxyl radical(·OH),especially crude polysaccharide,which demonstrated the highest activitie and its half elimination ratio(IC50) was 0.203 mg/mL.The extracts possessed strong scavenging activities on DPPH radical,the effect of ethyl acetate extracts was the strongest and its IC50 value was 0.008 mg/mL.Additionally,the obtained extracts had stronger deoxidize Fe3+ ability,the activity of the ethyl acetate extracts was somewhat stronger than that of Vc.