墨旱莲乙醇提取物动物致色素作用和对小鼠B16黑素瘤细胞黑素生成的影响

目的选择离体实验中对黑色素合成的关键酶—酪氨酸酶(tyrosinase,TYR)有激活作用的墨旱莲(旱莲草),研究其动物致色素作用和对小鼠B16黑素瘤细胞黑素生成及相关基因犤TYR、TYR相关蛋白(TRP-1/2)mRNA犦表达的影响。方法以棕色豚鼠为动物模型,用Schmorl法染色,计数含黑素的细胞;用多巴(DOPA)-氧化酶染色,计算每100个基底细胞中DOPA阳性细胞数。培养的小鼠B16黑素瘤细胞以四甲基偶氮唑盐比色(MTT)法、氢氧化钠(NaOH)法和体外氧化DOPA反应方法分别测定细胞的增殖活性、黑素生成量及TYR活性;逆转录-聚合酶链反应(RT-PCR)测定TYR及其TRP-1/2基因的表达。结果墨旱莲乙醇提取物可使豚鼠表皮基底层中含黑素颗粒细胞增多,使豚鼠表皮内DOPA阳性细胞增多(P<0.05);具有促进小鼠B16黑素瘤细胞黑素合成及TYR活性作用(P<0.05),对细胞TYR基因有上调作用,而对TRP-1/2mRNA的表达无明显作用。结论墨旱莲乙醇提取物具有促进黑素合成及上调酪氨酸酶基因表达的作用,对白癜风色素恢复有较好应用和开发的前景。

Effects of Ethanol Extract from Eclipta Prostrata L on Pigmentation in Brownish Guinea Pigs and on Melanogenesis in Cultured Murine Melanoma Cells B16

Objective To study the effects of Eclipta prostrata L (Mohanlian) ethanol extract, which activates tyrosinase in vitro, on melanogenesis and expression of its related genes(TYR, TRP-1/2 mRNA) in cultured B16 melanoma cells. Methods Using brownish guinea pigs as experimental models, cells containing melanin granules and DOPA-positive cells in 100 basal cells were counted by Schmorl and DOPA-oxidase stain methods respectively. The cells proliferation, melanogenesis and tyrosinase activity in cultured B16 cells were measured by MTT method, NaOH method and oxidative DOPA reaction respectively. The expression of TYR and TRP-1/2 mRNA were measured by RT-PCR. Results The ethanol extract of Eclipta prostrata L increased the cells with melanin granules in epidermal basal layer of guinea pigs and the DOPA-positive cells in epidermis. It also promoted melanogenesis and tyosinase activity(P<0.05) in B16 melanoma cells, and up-regulated TYR mRNA , but had no effects on TRP-1/2 mRNA. Conclusion Eclipta prostrata L ethanol extract have effects on activating melanogenesis and up-regulating TYR mRNA, which may be useful in treating vitiligo and promising in developing new drugs for treatment of vitiligo.