Abstract

Masriani, Dzul Fadly

West Kalimantan has an abundant variety of plant species, a potential source of new compounds for functional food, medicine, and cosmetics. This study aims to determine the oxidation, α-glucosidase, and tyrosinase inhibitory activities of the ethanol extract of seven plants from West Kalimantan, including the bark of tebelian (Eusideroxylon zwageri Teijsm. et Binnend), the flower of putat (Planchonia valida (Blume) Blume), leaves of tepung tawar (Costus speciosus (Koen) Smith), leaves of buas-buas (Premna serratifolia Linn), leaves of indigo (Indigofera tinctoria Linn), leaves of manggis (Garcinia mangostana Linn), and leaves of Hanjuang (Cordolyne fruticose Linn). The plants were obtained from Lanjak Village, Kapuas Hulu Regency, West Kalimantan. The ethanol extracts were obtained by extracting the seven plants by maceration with 96% ethanol that has been distilled for 3x24 h. The water extract obtained by maceration of the sample plants using distilled water carried out for 48 h. The antioxidant activities were determined using the free radical scavenging method 1,1-diphenyl-2-picrylhydrazyl (DPPH). The inhibitory activity of α-glucosidase and tyrosinase enzymes by monophenolase reaction was determined by the colorimetric method. The study indicated the ethanol and water extract of E. zwageri bark, P.valida flower, P. serrativeolia leaves, I. tinctoria leaves, G. mangostana leaves, and C. fruticosa leaves have antioxidant activities in IC50 were <15.63 - 653.84 µg/mL. Only the ethanolic extract of E. zwageri bark, P. valide flowers, and G. mangostana leaves were able to blockage the activity of α-glucosidase enzymes, about 150.54, 202.53, and 163.16 µg/mL, respectively. Tyrosinase activity was only blocked by the ethanolic extract from P. valide flower, was 772.01 µg/mL. The disclosure of antioxidant activity, α-glucosidase, and tyrosinase can be the basis for the use of these plants as raw materials in the functional food, cosmetics, and pharmaceutical industries.