Preliminary Screening of Selected Plant Extracts for Anti Tyrosinase Activity

Tyrosinase inhibition is an important approach towards controlling hyper pigmentation. We aimed to screen alcoholic extracts of 11 plants extract for their tyrosinase inhibitory activity. These plants have been used traditionally in the treatment of skin ailments and for the improvement of skin complexion. The extracts were quantified for total phenols, alkaloids and tannins. In vitro tyrosinase inhibition was performed with kojic acid as the positive control. Cell viability was tested on B16 F0 melanoma cells. The extracts of Rosa berberifolia, Punica granatum and Casiia angustifolia showed more than 80% inhibition at 500 mg/ml concentration. Nine of the extracts were also shown to have a high phenolic content greater than 200 mg/g of the plant material. The tyrosinase inhibitory activity of the extracts of Cassia angustifolia, Punica granatum and Rosa berberifolia were comparable with that of the control, kojic acid. The three extracts also showed lesser than 50% cytotoxicity at the concentrations tested. From the screening assays, it is seen that three plants have appreciable tyrosinase inhibitory activity. Hence, these plants may be further evaluated for their use in cosmetics and hyper pigmentation.