The inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet B-induced pigmentation via the suppression of endothelin-converting enzyme-1alpha.
Endothelin-1 (ET-1) has been reported to be expressed in human epidermis at both the gene and protein levels. ET-1 plays a pivotal role in ultraviolet B (UVB)-induced pigmentation due to its accentuated secretion after UVB irradiation and its function as a mitogen and as a melanogen for human melanocytes. We have recently found that endothelin-converting enzyme (ECE)-1alpha plays a constitutive role in the secretion of ET-1 by human keratinocytes and that an extract of Sanguisorba officinalis L. inhibits ECE activity in human endothelial cells, which predominantly express ECE-1alpha. In this report, to clarify the potential use of this botanical extract as a whitening agent, we examined whether this extract inhibits UVB-induced pigmentation in vivo. When this extract was applied to human keratinocytes after UVB irradiation, secretion of ET-1 by those cells was reduced, and this was accompanied by a concomitant increase in the secretion of inactive precursor Big endothelin-1. When hairless mice were exposed to UVB light and were treated with the extract, it suppressed the induction of ET-1 in the UVB-irradiated epidermis. In the course of UVB-induced pigmentation of brownish guinea pig skin, this extract significantly diminished pigmentation in UVB-exposed areas. These findings indicate that ECE-1alpha in keratinocytes plays a pivotal role in the induction of pigmentation following UVB irradiation and that an extract of S. officinalis, which inhibits ET-1 production in human keratinocytes, is a good ingredient for a whitening agent.
Hachiya
A
A
Kao Biological Science Laboratories, Haga, Tochigi, Japan. 309947@kastanet.kao.co.jp
Kobayashi
A
A
Ohuchi
A
A
Kitahara
T
T
Takema
Y
Y
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors*; D002478:Cells, Cultured; D019332:Endothelin-1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D000072396:Endothelin-Converting Enzymes; D006168:Guinea Pigs; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism / Q000528:radiation effects; D008666:Metalloendopeptidases; D051379:Mice; D008812:Mice, Hairless; D010858:Pigmentation / Q000187:drug effects* / Q000528:radiation effects*; D010936:Plant Extracts / Q000494:pharmacology*; D019685:Rosales / Q000737:chemistry*; D014466:Ultraviolet Rays
D019332:Endothelin-1; D010936:Plant Extracts; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes