5-甲氧补骨脂素及山柰素对黑素细胞的酪氨酸酶活性和增殖的影响

Effect of 5-Methoxypsoralen and Kaempferol on tyrosinase activity and proliferation of melanocytes

目的:探讨5-甲氧补骨脂素(5-MOP)、山柰素人正常黑素细胞(MC)酪氨酸酶(TYR)活性、增殖以及对细胞形态的影响。方法:采用多巴氧化法分别检测5-MOP、山柰素对培养的人正常黑素细胞TYR活性及对黑素细胞增殖的影响。结果:5-MOP随浓度增加,对黑素细胞的增殖率及TYR激活率呈剂量-时间依赖性的上调,以72h作用最强。与空白对照相比,差异均非常显著;山柰素对TYR活性有抑制作用,呈现明显的量效和时效关系,与对照组相比,10μM、50μM及100μM的山柰素作用48、72h,对TYR的抑制作用明显加强,以72h抑制率为最大。山柰素对黑素细胞的促增殖作用在1μM作用最强,随着浓度增加及作用时间的延长,增殖率呈下降之势。发现5-MOP作用的黑素细胞组,细胞树突增多,多为3、4极以上,而山柰素组2极细胞则明显增多。结论:山柰素是一种有应用前景的TYR抑制剂。MC树突的变化可能与MC内TYR的功能及黑素合成有关,在黑素合成过程中,TYR可能发挥着更为关键的作用,而MC增殖对黑素产生只起相对辅助作用。

Objective： To study the effects of 5 - methoxypsoralen （5 - MOP） and kaempferol on the tyrosinase activity and proliferation of the cultured normal human melanocytes. Methods： Tyrosinase activity of melanocyte was detected hy DOPA oxidase assay. Proliferation of melanocytes was determined using MTr method. Results： 5 - MOP promoted the tyrosinase activity in a dose- and time- dependent manner. The effect was greatest at 72 h. The tyrosinase activity in melanocyte exposed to 500 μM 5 - MOP for 72 h was markedly greater than that of control （ P 〈 0.01 ）. The proliferation of melanocytes treated with 1 - 100 μM 5 - MOP was significantly greater than that of control （ P 〈 0.01 ）. The number of melanocyte dendrites was more than that of control. Kaemferol inhibited tyrosinase activity in a dose - and time - dependent manner, which was greater than that of control after treatment with 10 μM, 50μM （ P 〈 0.05） and 100μM （ P 〈 0.01） for 48 and 72 h. Additionally, kaemferol promoted the proliferation of melanocytes in a dose - and time - dependent manner, which was similar to that of 5 - MOP. The number of melanocyte dendrites was less than that of controls. With the increase of kaemferol concentration and culture time, most multipolar cells changed into hipolar melanocytes. Conclusion： The results suggest that kaemferol is a strong potential inhihitor of tyrosinase. The change of melanocyte dendrites is probably related to tyrosinase activity and melanin synthesis, and the multipolar dendrite may be the marker of melanin synthesis in melanocyte. The tyrosinase activity may play a more significant role than melanocyte proliferation in melanin production.