Abstract: Objective To analyze the active principle of Melagenine and its effect on melanocytes of guinea epidermis.Methods The content of endothelins and sialic acid of Melagenine were determined by radioimmunoassay and spectrophotometer.The skin of the back of guinea pigs was treated with Melagenine and irradiated with infraredray.Then the biopsy specimens were taken from the treated and untreated back skin,sections and supe-rthin sections were prepared for special staining and TEM examination,respectively,the number melanocytes and melanin content index(MCI)were measured.Results The contents of en-dothelins and sialic acid in melagenine were 210.5±30.1 pg/mL and 147.9±12.1μg/mL,respectively;the number of melanocytes,the keratinocytes with melanin granules and the melanin content index were all in-creased significantly in the treated skin.Conclusions There are endothelins,carbohydrates and glycolipids in melagenine,endothelins can promote the proliferation of melanocytes,while carbohydrates and glycolipids can enhance intercellular recognition and adhesion.The result of the study shows that melagenine promotes the proliferation of melanocytes and synthesis of melanin in the skinof guinea pigs.

Key words: Sialic acids, Melanins, Melanocytes, Endothelins