Department of Cosmetic Science, Providence University, Taichung, Taiwan, ROC.
Phytomedicine. 2011 Nov 15;18(14):1244-9. doi: 10.1016/j.phymed.2011.06.028. Epub 2011 Jul 28.
Citrus fruits are the major source of flavonoids for humans, and flavanones are the main flavonoids in the Citrus species. Among the Citrus flavanones, the glycoside derivatives of naringenin, naringin and narirutin, are the most abundant in grapefruit. The present study aimed to investigate the molecular events of melanogenesis induced by naringenin in murine B16-F10 melanoma cells. Melanin content, tyrosinase activity and Western blot analysis were performed to elucidate the possible underlying mechanisms. Exposure of melanoma cells to naringenin resulted in morphological changes accompanied by the induction of melanocyte differentiation-related markers, such as melanin synthesis, tyrosinase activity, and the expression of tyrosinase and microphthalmia-associated transcription factor (MITF). We also observed an increase in the intracellular accumulation of β-catenin as well as the phosphorylation of glycogen synthase kinase-3β (GSK3β) protein after treatment with naringenin. Moreover, the activity of phosphatidylinositol 3-kinase (PI3K) was up-regulated by naringenin since the phosphorylated level of downstream Akt protein was enhanced. Based on these results, we concluded that naringenin induced melanogenesis through the Wnt-β-catenin-signalling pathway.
柑橘类水果是人类黄酮类化合物的主要来源，而类黄酮是柑橘属植物中的主要类黄酮。在柑橘类黄酮中，柚皮苷、柚皮苷和新橙皮苷的糖苷衍生物在葡萄柚中含量最丰富。本研究旨在探讨柚皮素在小鼠 B16-F10 黑素瘤细胞中诱导黑素生成的分子事件。通过测定黑素含量、酪氨酸酶活性和 Western blot 分析，阐明可能的潜在机制。柚皮素处理黑素瘤细胞后，细胞形态发生变化，同时诱导黑素细胞分化相关标志物的表达，如黑色素合成、酪氨酸酶活性以及酪氨酸酶和小眼畸形相关转录因子（MITF）的表达。我们还观察到β-连环蛋白在细胞内的积累增加，以及用柚皮素处理后糖原合成酶激酶-3β（GSK3β）蛋白的磷酸化增加。此外，柚皮素还能上调磷脂酰肌醇 3-激酶（PI3K）的活性，因为下游 Akt 蛋白的磷酸化水平增强。基于这些结果，我们得出结论，柚皮素通过 Wnt-β-连环蛋白信号通路诱导黑素生成。
