Antioxidant activities of solvent extracts from pomegranate endocarp

Abstract

This study was designed to investigate antioxidant activities of pomegranate endocarp extracts. Pomegranate endocarp extract contains the highest antioxidant function compared to pomegranate extracts from other parts. Pomegranate endocarp extract was fractionated with hexane, dichloromethane, ethyl acetate, butanol extract, and water, followed by evaluation for antioxidant activity. During this experiment, various antioxidant tests such as nitrite scavenging activity, reducing power, superoxide anion scavenging activity, ABTS+ scavenging activity, SOD like-activity, and DPPH radical scavenging activity were conducted on the CH2Cl2, EtOAc, BuOH, H2O fractions of pomegranate endocarp extract. Results showed that the ethyl acetate fraction contained the highest DPPH radical scavenging activity among the samples. For SOD like-activity, the dichloromethane fraction had the highest antioxidant activity. For superoxide anion scavenging activity, the ethyl acetate fraction had the highest antioxidant activity. In the ABTS+ scavenging activity test, the ethyl acetate fraction IC50 was 39.26 μg/mL, whereas that of the butanol fraction was 40.95 μg/mL. In testing reduction power at 0.1 mg/mL, the O.D. of the ethyl acetate fraction was highest at 1.404 and showed higher activity than ascorbic acid at 1.332. The results of the nitrite scavenging activity test were very similar to those of the SOD like-activity test. These results suggest that pomegranate endocarp extract may have value as a natural antioxidant.