Evaluation of total polyphenols and flavonoids contents and biological activities from fresh and dried samples of Blumea lacera (Burm. f.) DC. and Rorippa indica (L.) Hiern.

Abstract

This study aimed to determine the change in the total contents of polyphenols, flavonoids, and some biological activities (DPPH free radical scavenging and enzyme α-glucosidase inhibition) through the impact of heat during the drying process. The study was conducted on 96% ethanolic extracts from fresh and dried Blumea lacera (Burm. f.) DC. and Rorippa indica (L.) Hiern. Results indicated that the drying process increased the active ingredient content of Rorippa indica (L.) Hiern. and Blumea lacera (Burm. f.) DC.  by about 2,1 times. While biological activities of Rorippa indica in this study continued to be relatively weak, the samples of Blumea lacera indicated still alternately antioxidant and α-glucosidase inhibitory activities; specifically, the dried sample scavenged DPPH free radical best (IC_{50, DPPH} = 76.51 µg/mL) and preserving the freshness of sample conserved the α-glucosidase inhibitory activity (IC_{50, α-glucosidase} = 18.23 µg/mL).