Exp Dermatol. 2010 Aug;19(8):e340-2. doi: 10.1111/j.1600-0625.2009.01061.x.
Skin hyperpigmentation disorders as a result of abnormal melanin production induced by ultraviolet (UV) irradiation are both a clinical and a cosmetic problem. This melanin production is mediated by tyrosinase whose expression is positively regulated by microphthalmia-associated transcription factor (MITF). We recently found that expression of heat shock protein 70 (HSP70) inhibits melanin production. In this study, we searched for HSP70 inducers from Chinese herbs and selected an ethanol extract of Eupatorium lindleyanum (E. lindleyanum). Not only melanin production but also the activity and expression of tyrosinase were significantly suppressed in cells treated with E. lindleyanum extract as well as in HSP70-overexpressing cells. The expression of MITF was clearly suppressed in cells treated with E. lindleyanum extract but not in HSP70-overexpressing cells. These results suggest that E. lindleyanum extract suppresses the expression of tyrosinase and melanin production through both HSP70-dependent and HSP70-independent mechanisms.
皮肤色素沉着紊乱是由于紫外线（UV）照射引起的黑色素产生异常所致，既是临床问题也是美容问题。这种黑色素的产生是由酪氨酸酶介导的，其表达受小眼畸形相关转录因子（MITF）的正向调节。我们最近发现热休克蛋白 70（HSP70）的表达抑制黑色素的产生。在这项研究中，我们从中药中寻找 HSP70 诱导剂，并选择了泽兰（Eupatorium lindleyanum）的乙醇提取物（E. lindleyanum）。不仅黑色素的产生，而且细胞中酪氨酸酶的活性和表达也明显受到泽兰提取物以及 HSP70 过表达细胞的抑制。泽兰提取物处理的细胞中 MITF 的表达明显受到抑制，但 HSP70 过表达细胞中不受抑制。这些结果表明，泽兰提取物通过 HSP70 依赖和非依赖机制抑制酪氨酸酶的表达和黑色素的产生。
