喜树碱对B16F10细胞增殖及黑色素合成抑制机理

Inhibition mechanism of camptothecin on proliferation and melanin synthesis of B16F10 cells

为研究喜树碱(Camptothecin,CPT)对B16F10小鼠恶性黑色素瘤细胞的增殖及黑色素合成抑制机制,利用噻唑蓝(Methylthiazoletetrazolium,MTT)检测法、显微观察法、Na OH裂解法和多巴氧化法分析不同浓度的CPT对细胞增殖、形态、黑色素合成及酪氨酸酶活性的影响.结果显示:随着CPT浓度的增高和处理时间的延长,B16F10细胞的增殖抑制增强. 160μmol/L CPT处理72 h,B16F10细胞增殖抑制率达77. 0%,一定范围内呈现时间和浓度依赖性(P <0. 05).同时不同浓度CPT对细胞黑色素合成和酪氨酸酶活性也具有明显抑制作用,40μmol/L CPT处理72 h,细胞中黑色素的合成量为85. 37%,酪氨酸酶的活性为56. 4%(P <0. 05).结果表明,喜树碱能有效抑制小鼠黑色素瘤细胞B16F10的增殖和细胞内的黑色素的产生,其机制可能与抑制酪氨酸酶的活性有关.

The inhibition mechanism of proliferation and melanin synthesis of B16F10 cell induced by Camptothecin（CPT） was studied. Different concentrations CPT influences of Methylthiazoletetrazolium（MTT） cytotoxicity assay, microscope observation-assay, NaOH cracking-assay and L-Dopa oxidation-assay on the proliferation, cellular morphology, melanin synthesis and tyrosinase activity of B16F10 cells were investigated. The results showed that the B16F10 cells inhibition rate increased with the increase of CPT concentration and induction time.When the concentration of CPT was 160 μmol/L,the proliferation inhibition rate of B16F10 cells was 77.0% for 72 h treated group, which showed time- and concentration- dependent manner（ P 〈0.05）. Meanwhile, the melanogenesis and tyrosinase activity of cells were depressed sharply induced by CPT at different concentrations. When the concentration of CPT was 40 μmol/L, melanin synthesis and tyrosinase activity of cell were 85.37% and 56.4% for 72 h treated group, respectively （ P 〈0.05）.This study revealed that, camptothecin could inhibit the proliferation of B16F10 cells as well as the melanogrnesis effectively.The mechanism may be related to the inhibition of tyrosinase activity.