Anti-Tyrosinase Activity OfStachytarpheta Cayennensis in Vitro

Tyrosinase, also known as polyphenol oxidase, is a key enzyme that catalyzes synthesis of melanin in plants, microorganisms and mammalian cells. Melanin biosynthesis inhibitory compounds are useful for skin whitening agents used in cosmetics and also as a remedy for disturbances in pigmentation. Contributing to their roles in tissue remodeling in health and disease, several studies have reported investigations on plant extracts as inhibitors of proteinases and as anti-oxidants. The correlation between the radical scavenging activity and tyrosinase inhibitory activity designate the ability of the compound in preventing free radical caused skin cells damage, anti-wrinkle and reduce hyperpigmentation. Phenoliclike structure in their compounds and were reported to possess tyrosinase inhibitory effect. Arbutin, kojic acid and kojic derivative were used as whitening cosmetic and medicines, but clinical effects of these compounds are unsatisfactory. The polyphenolic compounds found in many plants were gained interest for cosmetic product development as they might possess less toxicity than the synthetic compounds. The usage of pure chemical in the cosmetic product such as hydroquinone as whitening agent was reported to be toxic, induce severe skin irritation and skin cancer in long-term used. The anti-tyrosinase activity of the different plant extracts was determined by using mushroom tyrosinase as a suitable model system. The antioxidant based on DPPH scavenging activity and tyrosinase inhibitory activities in vitro were performed and determined for the correlation of both activities. The results showed that antityrosinase activity was not in dose dependent manner with the plant extract, which have shown 10.8% inhibition at the concentration of 20μg/ml. This result suggests that the plant extract might be used as skin whitening and anti- ageing agents.