Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/51719
標題: 台桑二號不同萃取方式對酪胺酸酶活性及黑色素生成之影響
Effects of mulberry leaf extracts on tyrosinase activity and melanin contents from Morus alba L.
作者: 羅玉青
Lo, Yu-Ching
關鍵字: 桑葉;Mulberry leaves;酪胺酸酶;活性;黑色素瘤細胞;美白評估;麴酸;tyrosinase activity;melanoma cell;whitening;kojic acid
出版社: 食品暨應用生物科技學系
摘要: 
酪胺酸酶(Tyrosinase : EC 1.14.18.1)是一種含銅的多酚氧化酶(polyphenol oxidase),也是催化黑色素(melanin)生合成的關鍵酵素,在黑色素形成過程中扮演重要角色。近年來許多研究都在嘗試著從天然植物中,尋找有效的酪胺酸酶抑制物,並進而應用於化妝品的製造。雖然桑樹(如桑根白皮)被報導有美白作用,但有關桑葉的美白作用至今未有研究報導。因此本研究的目的在探討台灣主要栽種桑品系 - 台桑二號 (Morus alba L. var. acidosa G. cv. Taisang 2) 之桑葉萃取物對酪胺酸酶活性以及對人體黑色素瘤細胞抑制黑色素形成能力的影響。 作法為:將50%乙醇桑葉萃取物(MEE-50)和95%乙醇桑葉萃取物(MEE-95),分別以試管及細胞(A2058 cells)模式,測定其細胞存活率、細胞內酪胺酸酶活性及黑色素活性分析。 結果顯示:1)在試管試驗中相同濃度時,桑葉乙醇萃取物比水萃取物對酪胺酸酶有較佳的抑制能力;2)桑葉中富含之槲皮酮、槲皮酮苷及芸香苷對酪胺酸酶抑制能力為: 麴酸>槲皮酮>芸香苷>槲皮酮苷;3)從實驗中得知台桑二號50%及95%乙醇萃取物,在濃度1000µg/ml時,具有細胞毒性;4)在細胞內抗酪胺酸酶活性方面,在濃度250-500 µg/ml時,以MEE-50桑萃取物效果最好,但與控制組麴酸(100 µg/ml )間相比有顯著差異p<0.05;5)台桑二號桑葉粗萃物在試管試驗具有抑制酪胺酸酶的能力,與細胞結果有相同趨勢,未來可利用試管試驗作為原料篩選及產品開發的參考依據。

Tyrosinase or polyphenol oxidase (EC 1.14.18.1) is a copper-containing enzyme that is involved in the synthesis of melanin. In recent years many researchers have attempted to seek effective tyrosinase inhibitors from natural sources for applications to the cosmetics manufacturing. Although the mulberry tree (for example White Mulberry Root-bark) has been reported in media news that it has skin whitening effect, no experimental evidence is available to support this finding. In this research, we used Taisang No. 2 (Morus alba L. var. acidosa G. cv. Taisang 2), which is the main species of mulberry trees cultivated in Taiwan, to study the inhibition of tyrosinase and melanin formation in human melanoma cells. The leaves were extracted with water (MWE), 50% ethanol (MEE-50) or 95% ethanol (MEE-95) for determinations of the cell viability effect, tyrosinase activity and melanin content in test tube and in cultured cells (A2058 cells).. The results show that: 1) The 50% ethanol extracts had a higher tyrosinase inhibitory activity than the other two extracts; 2) Some phenolics contained in the mulberry leaves (quercetin, quercitrin, rutin) inhibited tyrosinase activity in the order: kojic acid(as positive control)>quercetin>rutin>quercitrin; 3) MEE-50 and MEE-95 were cytotoxicity to A2058 cell in a dose-dependent manner (1000µg/ml ). 4) MEE-50 had a higher tyrosinase inhibitory activity than the other two extracts to A2058 cell in a dose-dependent manner (250-500µg/ml); 5)These results demonstrate that the extracts of Taisang No. 2 mulberry leaves have the potential to suppress tyrosinase activity and melanin formation. The results suggest that these effects may be related to the phenol compounds.
URI: http://hdl.handle.net/11455/51719
Appears in Collections:食品暨應用生物科技學系

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.