Antityrosinase and antioxidant activities of selected Thai herbal extracts

Abstract

Tyrosinase inhibitors and antioxidants have been used in cosmetics as skin whiteners. The aims of the
present study were to test the anti-tyrosinase and antioxidant activities of Thai herbal extracts in indigenous
use as skin toneres. Eight Thai herbal extractes were investigated using the dopachrome method for assaying
anti-tyrosinase and the DPPH free radical scavenging activity for assaying antioxidant activity. Garcinia
Mangostana Linn. Trigonostemon reideoides. and Curcuma aromatica Salisb. extracts showed strong antityrosinase
acitivity with percentage tyrosinase inhibition values of 74.55, 50.23 and 42.45 respectively
while G. mangostana Linn, Nelumbo nucifera Gaertn. and T. reideoides. extracts showed high antioxidant
activity with the EC50 values at concentrations of 4.03 ,4.88 and 7.52 μg/ml, respectively. In conclusion,
the herbal extracts of G. mangostana Linn , T. reideoides.and N. nucifera Gaertn. have potential for use as
skin whiteners in cosmetic formulations.