【作者】 徐继敏；

【导师】 何光源；

【作者基本信息】 华中科技大学 ， 生物化学与分子生物学， 2009， 硕士

【摘要】 白发的发生主要是由于毛囊中黑素细胞酪氨酸酶的活性降低或丧失,合成黑色素的功能减退,使毛干中缺乏黑色素而引起。传统医学治疗白发的常用中药有何首乌、黑芝麻等,目前国内对于何首乌疗效的研究较多,关于黑芝麻在白发治疗方面的研究很少。为了研究黑芝麻在治疗白发方面的疗效和作用机制,本课题采用水提法提取黑芝麻有效成分,以鼠B16F1黑素瘤细胞为模型,运用生物化学,分子生物学和免疫学方法,在细胞水平和分子水平上,研究黑芝麻水提液对黑素瘤细胞增殖、酪氨酸酶活性、黑素生成量及黑素合成途径相关基因表达的影响,并探讨黑芝麻促进黑色素生成的机理。黑芝麻水提液能够使B16F1黑素瘤细胞的增殖率和活性有所提高(P>0.05);促进B16F1黑素瘤细胞酪氨酸酶活性显著增强(P<0.05),黑色素生成量显著增加。在分子水平上,RT-PCR和Western结果显示,黑芝麻水提物能够显著促进小眼畸形相关转录因子(MITF)的转录和翻译,其主要下游基因酪氨酸酶(TYR)的转录和翻译也呈现同步增强,并且随着处理浓度越大,增强效果越明显;酪氨酸酶相关蛋白-1(TRP-1)和酪氨酸酶相关蛋白-2(TRP-2)的表达无显著变化(P>0.05)。本课题证实黑芝麻水提液在体外能显著增加黑素瘤细胞酪氨酸酶的活性,有效刺激B16F1黑素瘤细胞中黑素合成,实验结果表明这种效果可能是通过促进MITF基因的表达,调控TYR基因在mRNA和蛋白质水平上增强表达来完成。更多还原

【Abstract】 White hair is caused by the lack of melanin in hair, which results from loss of tyrosinase activity in melanoma cells of Hair follicle. Semen Sesami Nigrum is a traditional medicine of curing white hair. To study the effect and mechanism of Semen Sesami Nigrum on white hair cure, we treated murine B16F1 Melanoma cells with 3 different concentrations of water extract of Semen Sesami Nigrum (WES). The effects of WES on cell viability, tyrosinase activity and melanogenesis of B16 murine melanoma cells were studied using Biochemical Molecular Biological and Immunological methods to clarify the mechanism of its stimulating effect on melanogenesis.B16F1 cells were incubated with three different concentrations of WES for 72h and then cell viability, tyrosinase activity, melanin content were respectively measured.The protein and mRNA expression of melanogenesis key enzymes were investigated by western Blotting and RT-PCR.In the range of experimental dose, WES increased B16 cell viability (P>0.05).,and also increased the activity of tyrosinase and melanin content significantly in a dose-dependent manner (P<0.05). The increasing mRNA and protein expression of TYR and MITF were also observed in a dose-dependent manner (P<0.05). No effect was observed on either mRNA or protein expression of TRP-1 and TRP-2.WES could Significantly increase the tyrosinase activity, and enhance the subsequent process of melanogenesis in B16 melanoma cells, which may be attributed to the increasing expression of MITF, which Controls the Transcription of TYR gene on mRNA and protein levels.更多还原