Itoh Kimihisa, Hirata Noriko, Masuda Megumi, Naruto Shunsuke, Murata Kazuya, Wakabayashi Keitaro, Matsuda Hideaki
School of Pharmacy, Kinki University, Osaka, Japan.
Biol Pharm Bull. 2009 Mar;32(3):410-5. doi: 10.1248/bpb.32.410.
The 50% ethanolic extract (CH-ext) obtained from the unripe fruit of Citrus hassaku exhibited significant tyrosinase inhibitory activity. The CH-ext showed antioxidant activity, such as superoxide dismutase (SOD)-like activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Activity-guided fractionation of the CH-ext indicated that flavanone glycoside-rich fractions showed potent tyrosinase inhibitory activity. Further examination revealed that the tyrosinase inhibitory activity and antioxidant activity of the CH-ext were attributable to naringin and neohesperidin, respectively. The CH-ext showed inhibition of melanogenesis without any effects on cell proliferation in cultured murine B16 melanoma cells after glucosamine exposure. The topical application of the CH-ext to the dorsal skin of brownish guinea pigs showed in vivo preventive effects against UVB-induced pigmentation.
从日本夏橙未成熟果实中获得的50%乙醇提取物（CH-ext）表现出显著的酪氨酸酶抑制活性。CH-ext具有抗氧化活性，如超氧化物歧化酶（SOD）样活性和1,1-二苯基-2-苦基肼（DPPH）自由基清除活性。对CH-ext进行活性导向分级分离表明，富含黄烷酮糖苷的级分显示出较强的酪氨酸酶抑制活性。进一步研究发现，CH-ext的酪氨酸酶抑制活性和抗氧化活性分别归因于柚皮苷和新橙皮苷。在氨基葡萄糖处理后，CH-ext对培养的小鼠B16黑色素瘤细胞的黑色素生成有抑制作用，且对细胞增殖无任何影响。将CH-ext局部应用于棕色豚鼠背部皮肤，显示出对紫外线B诱导色素沉着的体内预防作用。
