Tea catechins, the main bioactive polyphenols in green tea, are well known for their health promoting effects. Previous studies have shown that gallocatechin-3-gallate (GCG), epigallocatechin-3-gallate (EGCG) and epicatechin-3-gallate (ECG) exerted strong inhibitory effects on mushroom tyrosinase activity in vitro, whilst EGCG inhibited melanogenesis in vivo, yet the underlying mechanisms are not entirely clear. In this study, we (i) evaluated and compared the inhibitory effects of the main tea catechins (GCG, EGCG, and ECG) on melanogenesis in B16F10 melanoma cells, and (ii) explain the underlying mechanisms. The results showed that the tea catechins significantly suppressed tyrosinase activity and melanin synthesis in B16F10 cells, where the effects of ECG > EGCG > GCG. Interestingly, the inhibitory effects of the catechins were stronger than those of arbutin (AT), a well-known depigmenting agent. Moreover, GCG, EGCG, and ECG regulated the melanogenesis of B16F10 cells through the cAMP/CREB/MITF pathway. These results revealed catechins could be used as anti-melanogenic agents to protect cells from abnormal melanogenesis.

茶儿茶素是绿茶中的主要生物活性多酚，以其促进健康的作用而闻名。先前的研究表明，加洛儿茶素-3-没食子酸酯（GCG），表没食子儿茶素-3-没食子酸酯（EGCG）和表儿茶素-3-没食子酸酯（ECG）在体外对蘑菇酪氨酸酶活性具有强烈的抑制作用，而EGCG却在体内抑制了黑素生成。潜在的机制尚不完全清楚。在这项研究中，我们（i）评估并比较了主要茶儿茶素（GCG，EGCG和ECG）对B16F10黑色素瘤细胞黑色素生成的抑制作用，并且（ii）解释了其潜在机制。结果表明，茶儿茶素能显着抑制B16F10细胞的酪氨酸酶活性和黑色素合成，其中ECG> EGCG> GCG的影响。有趣的是 儿茶素的抑制作用要强于著名的脱色剂熊果素（AT）。此外，GCG，EGCG和ECG通过cAMP / CREB ​​/ MITF途径调节B16F10细胞的黑色素生成。这些结果表明儿茶素可以用作抗黑色素生成剂，以保护细胞免受异常黑色素生成的影响。