Cornus officinalis Methanol Extract Upregulates Melanogenesis in Melan-a Cells

Cornus officinalis is widely distributed in Korea, and its fruit has been used to make as herbal drug for traditional medicine in Korea, Japan, and China because of its tonic, analgesic, and diuretic properties. However, the effects of C. officinalis methanol extract (COME) on melanogenesis remain poorly understood. We evaluated the melanogenic capability of COME in melan-a cells, which are immortalized mouse melanocytes. COME increased melanin synthesis in a dose-dependent manner. Treatment with 12.5 mu g/mL of COME significantly increased melanin content by 36.1% (p < 0.001) to a level even higher than that (31.6%) of 3-isobutyl-1-methyl-xanthine, a well-known pigmentation agent. COME also upregulated tyrosinase activity and its messenger RNA and protein expression. In addition, COME upregulated the expression of tyrosinase-related proteins 1 and 2 and microphthalmia-associated transcription factor-M messenger RNA expression. These results imply that COME may be appropriate for development as a natural product to treat hair graying.