中药单体胡椒碱促进表皮黑素细胞黑素合成的实验研究

目的：研究中药单体胡椒碱对表皮黑素细胞黑素合成的影响，初步探讨胡椒碱影响表皮黑素细胞黑素合成的作用机制。方法：培养的表皮黑素细胞分别以系列浓度的胡椒碱作用24、72、120h，测定细胞增殖率、黑素含量，激光共聚焦显微镜观察并定量分析荧光染色后细胞内酪氨酸酶、酪氨酸酶相关蛋白酶(TRP)1、TRP2的表达情况。结果：胡椒碱呈浓度依赖性促进黑素合成。且作用72h时效果最明显。0．50mmol／L胡椒碱作用72h可促进表皮黑素细胞酪氨酸酶、TRP1的表达，而对TRP2的表达无明显影响。结论：中药单体胡椒碱可轻度抑制表皮黑素细胞的生长，明显促进表皮黑素细胞的黑素合成，其机制可能主要通过上调酪氨酸酶和TRP1的表达而发挥作用。

Researches on enhanced melanogenesis in the response of epidermal melanocytes by piperine

Objective: To study the effects of piperine, a natural chemical on the pigment formation in epidermal melanocytes and to explore the mechanism of melanogenesis induced by piperine. Methods: The melanocytes were incubated with five different concentrations of natural piperine for 24 h, 72 h and 120 h, respectively. Then melanin content, cellular proliferation rate were measured. The changes of intracellular expression of tyrosinase, TRP1 and TRP2 were observed by laser scanning confocal microscopy. Results: High dose of piperine(> 0.50 mmol/L)could inhibit the proliferation of epidermal melanocytes, and piperine could increase the cellular melanin content in dose-dependent manner,which was most obvious at 72 h. At the concentration of 0.50mmol/L, piperine could stimulate the expression of tyrosinase,TRP1, but had no effects on TRP2. Conclusions: Piperine can stimulate melanogenesis and slightly inhibit the proliferation of epidermal melanocyte, which may be induced by upregulations of tyrosinase and TRP1.