Mulberry (Morus alba L.) leaves containing many nutritional components are the best food for silkworms. The extracts from mulberry leaves have a potent antihyperglycemic activity in diabetic mice. Many phenolic compounds have been identified from the root bark of mulberry tree. Morus alba L. also contains rutin, isoquercitrin, and astragalin. The root bark of Morus alba has been shown to have a skin whitening effect.
Lee et al. (23) investigated the in vitro effects of an 85% methanol extract of dried Morus alba leaves on melanin biosynthesis. These extracts inhibited the tyrosinase activity that converts dopa to dopachrome in the biosynthetic process of melanin. Mulberroside F (moracin M-6, 30-di-O-beta-D-glucopyranoside), which was obtained after the bioactivity-guided fractionation of the extracts, showed inhibitory effects on tyrosinase activity and on the melanin formation of melan-a cells. But its activity was low and weaker than that of KA.