The study of inhibitory effect of lotus seedpod extract on melanogenesis

• Main Authors: Ting-Shuan-Lee, 李庭暄
• Other Authors: Jing-Hsien Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/nsb2vf

碩士 === 中山醫學大學 === 營養學研究所 === 102 === Melanogenesis has many important physiological functions, including photo-protection of human skin from UV irradiation. Melanin synthesis is stimulated by α-melanocyte stimulating hormone (α-MSH). However, abnormal melanogenesis causes hyperpigmentation in the skin, which results in serious aesthetic issues and increases the risk of skin cancer. Previous studies have indicated lotus seedpod extract (LSE) has antioxidant, anti-aging and anticancer activities. Therefore, in this study we examined the effect of LSE on melanogenesis and signaling pathways in vitro and in vivo. Results showed that non-cytotoxic doses of LSE and its main composition Epigallocatechin (EGC) reduced α-MSH-induced both tyrosinase activity and melanin production in mouse melanoma B16F0 cells. Western blotting data showed LSE and EGC inhibited the expression of tyrosinase and TRP-1 (tyrosinase-related protein 1), Phosphorylation of p38 MAPK and PKA by α-MSH stimulation was efficiently blocked by LSE treatment. Further, LSE also suppressed the nuclear levels of CREB causing the consequent disturbed activation of MITF in α-MSH-stimulated B16F0 cells. The LSE-inhibited α-MSH-induced tyrosinase expression appeared be a consequence of MITF inactivation, because its DNA binding activity was suppressed by LSE. Besides, LSE inhibited melanin production in the ear skin of C57BL/6 mice exposed to UVB and the molecules involved in the melanogenesis. These findings suggested that LSE might be used as a potential natural whitening agent.