芪白合剂对培养的人黑素细胞生长及酪氨酸酶、MITF基因表达的影响

Effects of Qibai-mixture on the proliferation and mRNA expression of tyrosinase and microphthalmia transcription factor in cultured human melanocytes

目的研究芪白合剂对黑素细胞生长及黑素细胞酪氨酸酶、小眼相关转录因子(MITF)基因表达的影响。方法芪白合剂组方黄芪、党参、白芷、白蒺藜、鸡血藤,水煎煮浓缩成3g/mL,取青紫蓝兔,按12 mL·kg^(-1)·d^(-1)连续灌胃3天后于末次给药1 h,2 h和5 h无菌采血,收集血清;采用体外培养正常人黑素细胞,观察不同采血时间的芪白合剂含药血清对黑素细胞生长、酪氨酸酶的活性、黑素合成以及用RT-PCR的方法测定其对酪氨酸酶、MITF基因表达的影响。结果含药血清与对照血清比较,能明显促进黑素细胞生长,上调酪氨酸酶的活性和黑素合成(P<0.05),以1 h和2 h所采血清作用明显。并可以促进酪氨酸酶和MITF的基因表达。结论芪白合剂可以通过直接作用于黑素细胞和酪氨酸酶通道来促进黑素合成。

Objective To investigate the effects of Qibai-mixture on the proliferation, tyrosinase activity and mclanogenesis of cultured human melanocytes. Methods The water decoction of Qibai-mixture, which consisted of huangqi, dangshen, baizhi, baijili, jixueteng, was concentrated to 3 g/mL, then was used to treat black, purple and blue rabbits by intragastric administration at a dose of 12 mL·k^-1·d^-1 for three days. Serum samples were collected from the rabbits at 1 h, 2 h and 5 h after the last intragastric administration. Human melanocytes were cultured with the serum samples or drug-free serum as control for 24 or 48 h. The proliferation, tyrosinase activity and melanogenesis of melanocytes were detected by MTT method, DOPA-oxidation, and NaOH-assay, respectively. The mRNA expression of tyrosinase and mierophthalmia transcription factor （MITF） was examined with semiquantitative RT-PCR. Results Compared with the control serum, the serum collected at 1 h and 2 h after the last administration could significantly stimulate the proliferation, up-regulate the activity of tyrosinase, promote the melaningenesis, and increase the mRNA expression of tyrosinase and MITF, of the cultured melanocytes. Conclusion These results demonstrate that Qibai-mixture could promote melanogenesis by directly acting on melanocytes and tyrosinase signal pathway.