Camellia sinensis water extracts posses anti-melanogenic effects by decreasing both tyrosinase activity and protein expression. - GreenMedInfo Summary

Tea contains polyphenols and is one of the most popular beverages consumed worldwide. Because most tyrosinase inhibitors that regulate melanogenesis are phenol/catechol derivatives, this study investigated the inhibitory effect of Camellia sinensis water extracts (CSWEs), including black tea, green tea, and white tea extracts, on melanogenesis in immortalized melanocytes. CSWEs inhibited melanin accumulation and synthesis and tyrosinase activity in a concentration-dependent manner, and their inhibitory effects were superior to those of arbutin, a well-known depigmenting agent. The anti-melanogenic activity of black (fermented) tea was higher than that of a predominant tea catecholamine, epigallocatechin gallate. CSWEs, especially black tea extract, also decreased tyrosinase protein levels in a concentration-dependent manner. These results suggest that the anti-melanogenic effect of CSWEs is mediated by a decrease in both tyrosinase activity and protein expression and may be augmented by fermentation. Thus, CSWEs could be useful as skin-whitening agents in the cosmetic industry.