Yamakoshi Jun, Otsuka Fujio, Sano Atsushi, Tokutake Shoichi, Saito Makoto, Kikuchi Mamoru, Kubota Yoshiro
Research and Development Division, Kikkoman Corporation, Noda, Noda City, Chiba, Japan.
Pigment Cell Res. 2003 Dec;16(6):629-38. doi: 10.1046/j.1600-0749.2003.00093.x.
Antioxidants such as vitamins C and E have been reported to inhibit the progression of ultraviolet (UV) radiation-induced pigmentation in the skin of hairless mice. However, little is known of the lightening effect of proanthocyanidin, a powerful polyphenolic antioxidant, on UV-induced pigmentation of the skin. We investigated the lightening effect of oral administration of a proanthocyanidin-rich grape seed extract (GSE) using guinea pigs with UV-induced pigmentation. These pigmented guinea pigs were fed diets containing 1% GSE or 1% vitamin C (w/w) for 8 weeks. GSE-feeding had an apparent lightening effect on the guinea pigs' pigmented skin. Histologic evaluation demonstrated a decrease in the number of 3,4-dihydroxyphenylalanine (DOPA)-positive melanocytes as well as 8-hydroxy-2'-deoxyguanosine (8-OHdG)-positive, Ki-67-positive, proliferating cell nuclear antigen (PCNA)-positive melanin-containing cells in the basal epidermal layer of the UV-irradiated skin in GSE-fed guinea pigs. In contrast, these parameters did not change in the skin of vitamin C-fed or control guinea pigs. GSE inhibited the activity of mushroom tyrosinase and also inhibited melanogenesis without inhibiting the growth of cultured B16 mouse melanoma cells. In conclusion, we demonstrated that oral administration of GSE is effective in lightening the UV-induced pigmentation of guinea pig skin. This effect may be related to the inhibition of melanin synthesis by tyrosinase in melanocytes and the reactive oxygen species (ROS)-related proliferation of melanocytes.
据报道，抗氧化剂如维生素C和E可抑制无毛小鼠皮肤中紫外线（UV）辐射诱导的色素沉着进展。然而，对于原花青素这种强大的多酚类抗氧化剂对紫外线诱导的皮肤色素沉着的美白效果知之甚少。我们使用紫外线诱导色素沉着的豚鼠研究了口服富含原花青素的葡萄籽提取物（GSE）的美白效果。这些色素沉着的豚鼠被喂食含有1% GSE或1%维生素C（重量/重量）的饮食8周。喂食GSE对豚鼠色素沉着的皮肤有明显的美白效果。组织学评估显示，在喂食GSE的豚鼠紫外线照射皮肤的基底表皮层中，3,4-二羟基苯丙氨酸（DOPA）阳性黑素细胞以及8-羟基-2'-脱氧鸟苷（8-OHdG）阳性、Ki-67阳性、增殖细胞核抗原（PCNA）阳性的含黑色素细胞数量减少。相比之下，在喂食维生素C的豚鼠或对照豚鼠的皮肤中，这些参数没有变化。GSE抑制蘑菇酪氨酸酶的活性，并且在不抑制培养的B16小鼠黑色素瘤细胞生长的情况下也抑制黑色素生成。总之，我们证明口服GSE可有效减轻豚鼠皮肤紫外线诱导的色素沉着。这种效果可能与抑制黑素细胞中酪氨酸酶的黑色素合成以及与活性氧（ROS）相关的黑素细胞增殖有关。
