Antimelanogenic effects of Arbutin

Paik, Jong Hyun; Lee, Mu Hyoung

Abstract

BACKGROUND: Arbutin is a glycosylated hydroquinone found at high concentration in certain plants capable of surviving extreme and sustained dehydration. It has been suggested as an inhibitory compound of melanogenesis. OBJECTIVE: The purpose of this study was to investigate the effect of arbutin on melanogenesis in cultured human melanocytes and to evaluate the effectiveness of arbutin in patients with melasma. METHODS: I. In vitro study:we examine the cell number, SRB assay, tyrosinase activity, and melanin contents of cultured human melanocytes in control(absence of arbutin) and experimental groups (presence of 10(-5) M, 10(-4) M, and 10(-3) M arbutin). II. In vivo study:6 patients with melasma applied a 3 % arbutin solution twice daily for 8 weeks. Clinical response to treatment was evaluated by patients' subjective assessment and MASI(Melasma Area and Severity Index) score after 8 weeks of treatment. RESULTS: I. In vitro study 1. The number of melanocytes was decreased in groups treated with 10(-5) M, 10(-4) M, 10(-3) M arbutin for 2 days and 10(-4) M, 10(-3) M arbutin for 7 days. 2. On SRB assay, the proliferation of melanocytes was decreased in groups treated with 10(-5) M, 10(-4) M, 10(-3) M arbutin for 2 days and for 7 days. 3. Tyrosinase activity was decreased in groups treated wtih 10(-4) M, 10(-3) M arbutin for 2 days and 10(-5) M, 10(-4) M, 10(-3) M arbutin for 7 days. 4. The melanin contents were decreased in group treated with 10(-3) M arbutin for 7 days. II. In vivo study 1. On patients'subjective assessment, one showed moderate improvement, one showed mild improvement, and the other four showed no change. 2. On MASI score, there was less than 10% improvement in all 6 patients. 3. Side effects were not found in all 6 patients. CONCLUSION: Although arbutin showed an inhibitory effect on cell proliferation, tyrosinase activity, and melanin synthesis in cultured human melanocytes, there was no significant effect of depigmentation in the patients with melasma.