异欧前胡素对人表皮黑素细胞酪氨酸酶和Rab27a的调节作用

Effects of isoimperaterin on regulation of tyrosinase and Rab27a in human epidermal melanocytes

目的:探讨异欧前胡素对体外培养的人表皮黑素细胞酪氨酸酶和Rab27a的凋节作用。方法:体外分离人表皮黑素细胞并纯化培养,随机分为对照组和实验组。对照组加入M-254培养基,实验组加入含25μmol/L异欧前胡素的M-254培养基,培养48h后倒置显微镜下观察黑素细胞的形态;MTT法检测黑素细胞活力;Western blot法检测黑素细胞酪氨酸酶和转运相关蛋白Rab27a的表达;L-多巴氧化法和NaOH法测定黑素细胞酪氨酸酶活性和黑素含量。结果:与对照组比较,实验组人表皮黑素细胞的树状突起变长,黑素细胞活力降低17.2%(P<0.05),黑素细胞酪氨酸酶表达下降30.3%(P<0.01),而Rab27a表达升高31.9%(P<0.05);酪氨酸酶活性降低25.6%(P<0.05);黑素含量降低30.9%(P<0.01)。结论:25μmol/L异欧前胡素使黑素细胞的树状突起变长,抑制黑素细胞活力,抑制黑素细胞酪氨酸酶的表达和活性,促进黑素转运相关蛋白Rab27a的表达,降低黑素细胞中黑素的含量。

OBJECTIVE：To investigate the effects of isoimperaterin on regulation of tyrosinase and Rab27a in cultured human epidermal melanocytes. METHODS：Human epidermal melanocytes were isolated and cultured. The cells were randomly divided into control and experimental groups. Melanocytes of the control group were cultured with M-254 culture medium. Cells of the experimental group were cultured with M-254 culture medium containing 25 μmol/L isoimperaterin. The cells were cultured for 48 h and observed using inverted microscopy. Cell vitality was assayed using MTT method. The expression of tyrosinase and transfer-related protein Rab27a were analyzed by western blotting. The activity of tyrosinase and the content of melanin were measured by L-dopa oxidation and NaOH method,respectively. RESULTS：Compared with the control group,the dendrites of melanocytes of experimental group were elongated after treatment with 25 μmol/L isoimperaterin for 48 h. Melanocyte vitality was reduced by 17.2% （P〈0.05）. Expression of tyrosinase was decreased by 30.3% （P〈0.01） and Rab27a was increased by 31.9% （P〈0.05）. The activity of tyrosinase was reduced by 25.6% （P〈0.05）. Melanin content was decreased by 30.9% （P〈0.01）. CONCLUSION：25 μmol/L isoimperaterin elongated melanocytic dendrites but inhibited melanocyte vitality. It also inhibited the expression and activity of tyrosinase and promoted the expression of transfer-related protein Rab27a to reduce the content of melanin in cultured human epidermal melanocytes.