Antioxidant activities of traditional medicinal plants from Lauraceae family in Sarawak

This study aims to determine the antioxidant activities of traditional plants from the Lauraceae family in Sarawak. Twenty selected plants from the Lauraceae family were collected from various mixed dipterocarp forests located in the Kuching and Samarahan Districts of Sarawak. Their antioxidant activities were evaluated on the methanolic extracts using the DPPH (2,2-Diphenyl-l-picrylhydrazyl ) assay. The findings indicated a large variation in the antioxidant activity of which ranged from 14.1 to > 500 µg/mL with a mean value of 184.1 µg/L. Amongst all the tested methanol extracts of the plant samples, the bark of L. grandis (EC50 value of 14.1 µg/mL) exhibited remarkable antioxidant activity when compared to vitamin E (EC50 value of 13.8 µg/mL) and quercetin (EC50 value of 11.7 ug/mL). In addition, the methanolic extracts of the roots of L. accedens var oblanceolaat, the leaves of Dehaasia longpetiolata and the bark of Beilschmiedia pulverulenta showed EC50 values of less than 30 µg/mL.