Determination of active constituents and antioxidant activity of premna trichostoma miq. leaf extract

Abstract

Premna trichostoma Miq. (Lamiaceae) mainly distribute in Asia including Thailand. Folk healers use this plant to treat fever as a juice, splash, and bathe. The aims of this study are to evaluate the quantity of active constituents and antioxidant activity of P. trichostoma leaf extract. Total phenolic compounds were determined using Folin-Ciocalteu method. Total flavonoid contents were determined by Aluminum chloride method. The amount of apigenin and kaempferol contents were analyzed by high performance liquid chromatography (HPLC). In addition, the antioxidant activity was evaluated by DPPH and ABTS assay. The results showed that total phenolic contents, total flavonoid contents, and the amount of apigenin and kaempferol of P. trichostoma leaf extract was 46.45±15.30 mg GAE/g extract, 25.48±2.02 mg CE/g extract, 11.16±0.04 and 4.54±0.08 µg/g extract, respectively. The IC50 values from the DPPH and ABTS assay was 117.50±1.22 and 36.14±1.53 µg/ml, respectively. This study shows the antioxidant properties and active constituents of P. trichostoma leaf extract which indicates the potentials for further development of this plant