红藻糖苷抑制黑色素形成的作用研究

Suppression of melanin formation by floridoside

探索红藻糖苷对生物体黑色素产生的抑制作用。利用黑素瘤细胞B16-F0评价红藻糖苷对细胞合成黑色素的影响;从抑制酪氨酸酶酶活角度研究其抑制机理。研究显示,红藻糖苷对黑素瘤细胞无明显细胞毒性,但呈浓度依赖性抑制细胞黑色素产生。红藻糖苷对酪氨酸酶的单酚酶和二酚酶活性都有抑制作用,单酚酶的IC50为89mmol/L;对二酚酶的抑制为可逆竞争性抑制,Ki为16.44 mmol/L。可见,红藻糖苷具有抑制细胞生成黑色素的能力,其机理与抑制酪氨酸酶活性有关。

To study the inhibitory effect of floridoside in red algae on the generation of melanin,the B16-F0 melanoma cells were used to evaluate the ability of floridoside on the biosynthesis of melanin. The effect of floridoside on the activity of tyrosinase was also detected for investigating the mechanism. Results indicated that floridoside showed no obvious toxicity to B16-F0 melanoma cells,but suppressed melanogenesis with the concentration dependence manner. Floridoside was discovered to inhibit both the monophenolase and the o-diphenolase activities. It influenced the steady state of monophenolase activity and IC50 was 89 mmol/L. The inhibition on o-diphenolase activity was in a concentration dependent manner,and 40 mmol/L floridoside reduced the steady state activity for 33. 08%.The inhibition kinetics analyzed by Lineweaver-Burk plots showed that floridoside was a reversible competitive inhibitor,and the inhibition constant was determined to be 16. 44 mmol/L for the free enzyme. In general,floridoside was potential to suppress the generation of melanin,and the mechanism was to inhibit the activity of tyrosinase,especially the activity of o-diphenolase.