Inhibitory effect of botanical extracts on melanin synthesis by suppressing function of endothelin 1 or its production

摘要

Endothelin-1 (ET-1) has been previously reported to be up-regulated at the transcriptional level in epidermis after ultraviolet (UV)B irradiation, playing an important role in UVB-induced pigmentation. We have recently found that extracts of Matricaia chamomilla L. and Althaea offcinalis L. suppress ET-1-induced intra-cellular calcium mobilization and proliferation of human melanocytes and that Sanguisorba officinalis L. extract inhibits ET-1 production of human keratinocytes. In this report, to clarify the availability of these botanical extracts for a whitening agent, we examined whether these botanical extracts inhibited UVB-induced pig-mentation in in vivo. When M. chamomilla extract was applied to human skin after UVB irradiation, pigmentation was significantly diminished. Similarly, extracts of A. offficinalis and S. officinalis also inhibited the UVB-induced pigmentation on brownish guinea pig skin. These findings indicate that botanical extracts, which inhibit ET-1-induced calcium mobilization and proliferation or ET1 production, are good ingredients for a whitening agent.