Depigmentation of melanocytes by the treatment of extracts from traditional Chinese herbs: a cell culture assay.
OBJECTIVE
To obtain potential skin whitening agents from traditional Chinese herbs, we tested changes of melanin content in melanocyte cell lines after treatment with extracts of 90 traditional Chinese herbs.


METHODS
Mouse melanocyte cell lines were used. Depigmentation activity of the herb extracts were first screened in Mel-Ab cells, and then re-evaluated in melan-a cells and co-culture of melan-a and SP-1 cells. Melanin content and cell viability were the two indications for evaluation. Tyrosinase activity and the expression of melanin synthesis related enzymes in cells treated with the herb extracts were also tested.


RESULTS
Nine herb extracts were proved to have depigmentation activity similar to or better than that of arbutin and low cytotoxicity to melanocytes. Two of them were more effective in co-cultured melan-a cells. Most of the effective herb extracts inhibited tyrosinase activity and the expression of tyrosinase. Some of them also inhibited tyrosinase related protein-1 and/or tyrosinase related protein-2 in cultured cells.


CONCLUSIONS
We have found 9 herb extracts to be promising skin whitening agents. Among them, water extract of Galla Chinensis and ethanol extract of Radix Clematidis exhibited higher depigmentation activity and caused lower tyrosinase activity in cell culture assays and are worthy to be further studied.
Zhong
Shaomin
S
Department of Dermatology, Peking University First Hospital, Beijing, China.
Wu
Yan
Y
Soo-Mi
Ahn
A
Zhao
Junyu
J
Wang
Ke
K
Yang
Shuxia
S
Jae-Ho
Yeon
Y
Zhu
Xuejun
X
D000818:Animals; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D008544:Melanocytes / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012880:Skin Pigmentation / Q000187:drug effects*
D004365:Drugs, Chinese Herbal; D012333:RNA, Messenger; D010088:Oxidoreductases; C064056:tyrosinase-related protein-1; D014442:Monophenol Monooxygenase