中草藥美白活性研究五倍子對B16黑色素細胞黑色素形成之抑制研究

現今草本精華之美白化妝品廣受女性朋友歡迎，所以本研究目的是對中草藥的美白活性成份研究。首先檢測以70 %丙酮或50 %乙醇萃取之30種中草藥，對抗氧化能力和黑色素生成的影響。結果顯示：五倍子、大黃、頷垂豆、安石榴、玫瑰具有較明顯之抑制酪胺酸酶(Tyrosinase)之活性，其IC50 分別為 22.00、77.75、80.04、120.13及127.00 mg/ml。且其清除DPPH自由基之活性，IC50分別為為3.78、23.19、24.87、11.77及14.62 mg/ml，其中以五倍子效果最好。再以a-MSH、UVA刺激B16細胞黑色素形成之細胞模式，進行五倍子之黑色素形成抑制研究，結果顯示:五倍子在無誘導劑處理細胞、UV照射兩天及a-MSH合併誘導誘導之下，均呈劑量依存性之抑制作用。另以Folin-Ciocalteu reaction及HPLC分析其主要植物化學成份分佈：得知五倍子富含總多酚類，且其主成份為1,2,3,4,6-Penta-O- -galloyl-b-D-glucose (PG)，再利用相同實驗方法分析PG的酪胺酸酶抑制作用，其IC50為 15 mM，且經由酵素動力學分析，屬於非競爭型抑制劑(Non-competitive inhibitor)。最後以親水軟膏為基劑，調製五倍子萃取物軟膏，進行動物皮膚刺激性試驗。觀察結果發現：2 g/g (w/w)、1 g/g (w/w)之五倍子濃度均不會引起小鼠皮膚過敏。所以，經由上述結果推論，五倍子應具皮膚美白化妝品開發研究之潛力。

Nowadays herbal medicines of whitening cosmetic are popular for women. For this reason, we attempted to find the whiting activity compound present in many herbal medicines used. First screen 70 % acetone or 50 % ethanol extracts of 30 differents kinds of herbal medicines that effects of antioxidation and melanin biosynthesis. Results showed that: Rhus javanica Linne 、Rheum palmatum Linne、Archidendron lucidum Benth、Punica granatum Linne and Rosa rugosa Thunberg showed a potent tyrosinase activity inhibition , IC50 value was 22.00, 77.75, 80.04, 120.13 and 127.00 mg/ml. The antioxidation of DPPH, IC50 value was 3.78、23.19、24.87、11.77 and 14.62 mg/ml, Rhus javanica Linne showed the most potent effect. In the cell culture assay use a-MSH、UVA induce melanogenesis in B-16 mouse melanoma cell. The results of the inhibitory effect of Rhus javanica Linne with no inducer and with inducer a-MSH co-culture and radiation UVA 2 days on melanin biosynthesis was observed in B-16 mouse melanoma cell all in a dose dependence. Then use Folin-Ciocalteu reaction and HPLC assay was used to identify the major compound: Rhus javanica Linne was richly in polyphenol and the major component was 1,2,3,4,6-Penta-O- galloyl-b-D-glucose (PG), and use the same tyrosinase activity inhibition assay PG whose IC50 value was 15 mM. By mushroom tyrosinase inhibition kinetics assay, the inhibition mechanism obtained from Lineweaver-Burk plots showed that 1,2,3,4,6-Penta-O-galloyl-b-D- -glucose is a non-competitive inhibitor. Then skin stimulate tests in animal modesl, results showing that both 2 g/g (w/w) and 1 g/g (w/w) Rhus javanica Linne, was not induce an allergic reaction in mice skin. Overall, the results indicate that the Rhus javanica Linne could be development as whitening cosmetic for skin care.