Inhibitory and Eliminating Effects of Yeast-extracted Melanoston on Pigmentation and Preexisting Pigmentation, Respectively

Kim, Jeong Soo; Park, Kyoung Tae; Ahn, Young Seob; Yu, Hee Joon

Abstract

BACKGROUND: Melanoston is a new melanogenesis inhibitor isolated from yeast. However, little is known about the mechanism of this agent in melanogenesis and also its clinical effectiveness on hyperpigmented lesions.
OBJECTIVE
The purpose of this study was to examine the inhibitory effect of melanoston on in vivo activity of tyrosinase.
METHODS
We assessed tyrosinase activity, which participates in the synthesis of melanin pigment and resides in melanocytes of guinea pig's epidermis, using immunohistochemical methods after application of 0.1% and 0.01% melanoston on the skin of guinea pigs. We also conducted an 8-week clinical trial on 30 women volunteers to determine the clinical efficacy and safety of melanoston. Participants were instructed to apply melanoston and vehicle on 7 small areas of skin on both forearms for 8 weeks, before and after UVB exposure, and they were examined daily for the first week, then weekly thereafter.
RESULTS
The lowest level of tyrosinase activity was observed at the 3rd week after application of 0.1% and 0.01% melanoston on the skin of guinea pigs, and melanoston had a relatively strong inhibitory effect on tyrosinase, as compared with vehicle and arbutin. Differences in the degree of pigmentation between areas treated with 0.5% melanoston and application of vehicle only, and between before and after UVB exposure were considered to be significant (p<0.001, on each time).
CONCLUSION
We conclude that melanoston has an inhibitory effect on melanogenesis and some eliminating effect on preexisting pigmentation.