Measurement of Total Phenolics, Antiradical Capacity and Reducing Power of Extracts of Chinese Medicinal Plants

P. cocos, B. ochracea, P. lactiflora, A. dahurica were procured and identified and seperately extracted using water (ethanol, methanol) in the ultrasonic cleaner. TPC, DPPH scavenging ability and reducing power (RP) were determined. The results from this study showed that P lactiflora had the highest content as 18.62 mg GAE/g dw in ethanol, whereas P cocos contained only 0.37 mg GAE/g dw in water and P lactiflora exhibits the highest capacity (68.97%) to reduce DPPH in methanol extract with lowest IC50 value of 1.12 mg dw/ml and 1.14 mg dw/ml in ethanol extract at a concentration of 1.6 mg dw/ml. In RP assay, P. lactiflora had highest FRAP values (37.65 mg AAE/g dw in methanol extract), and P cocos with least activity 3.25 mg AAE/g dw. The RP value has a apparently positive correlation with TPC and DPPH scavenging activity. TPC is remarkably related to its overall antioxidant ability. P lactiflora could be selected as an excellent antioxidant for functional foods as well as pharmaceutics.