龍眼籽抗老化成分研究

Anti-aging Constituents from seeds of Dimocarpus longan Lour.

詹秀珍(Hsiu-Chen Chan)

指導教授 ： 李慶國

共同指導教授 ： 蕭哲志

臺北醫學大學/藥學院/生藥學研究所/碩士(2011年)

摘要

龍眼為生長於亞熱帶地區的無患子科植物，龍眼籽在過去研究發現具有抗氧化、抗酪胺酸脢、抗醣化及抗癌等多種用途。而在過去實驗室以多種天然物作為抗老化活性篩選時，發現龍眼籽萃取物對基質金屬蛋白酶 (matrix metalloproteinases, MMPs) 具有抑制活性。皮膚中細胞外基質 (Extracellular matrix, ECM) 所內含之膠原蛋白、彈性蛋白及透明質酸可維持皮膚彈性及張力，而皮膚老化最主要的變化即為以細胞外基質為受質的基質金屬蛋白酶增高所致。
在本次實驗中，取龍眼籽甲醇粗萃取物，利用乙酸乙酯及正丁醇做分配萃取，得到龍眼籽乙酸乙酯層、正丁醇層及水層萃取物，再以活性追蹤方式，利用gelatin zymography活性實驗，對此三層做活性評估，發現乙酸乙酯層萃取物對MMPs酵素抑制效果最佳，故以乙酸乙層萃取物做進一步成分分離，得到11種化合物 (DL1 - DL11)，包括八個tannin類化合物、一個glycoside類化合物及兩個其他類化合物，其中四個為新化合物。
再將此11種化合物繼續投入gelatin zymography活性實驗，最後得到DL3 (1-O-galloyl-6-O-luteoyl-α-D-glucopyranose) 為具有最佳抑制酵素活性之化合物，對MMP-2之IC50為49.63 ?b 11.00 uM，且在細胞存活率實驗中也發現對細胞並無毒殺作用 (存活率>90%)，期待可發展為具抗皮膚老化作用之保養品。

關鍵字

龍眼籽 ； 抗老化 ； 基質金屬蛋白酶

並列摘要

Longan (Dimocarpus longan Lour.) is a subtropical evergreen tree belonging to the family Sapindaceae. Longan seeds have been found to possess antioxidant, anti-tyrosinase, anti-glycated and anti-cancer activities. In the past, there were samples collected to estimate anti-aging activity in our lab. The result was found that longan seed possesses excellent inhibitory activity toward MMPs.
The three major extracellular components of the dermis are collagen, elastin, and hyaluronic acid. Collagen, elastin, and hyaluronic acid provide elasticity and resilience in skin. Degradation of dermal collagen by increasing MMPs impairs the structural integrity of the skin and causes cutaneous aging.
In this study, the methanol extract of longan seeds was analyzed the anti-aging effect by inhibiting the activity of MMP-2 and MMP-9. After the methanol extract of longan seeds was partitioned by ethyl acetate (EA), n-butanol and H2O, the EA layer was chosen to be further separated due to its better inhibitive activity of MMP-2 and MMP-9. There are compounds purified from the EA layer of longan seeds by open column chromatography and high performance liquid chromatography (HPLC). DL1 - DL11 were evaluated the anti-MMP-2 and anti-MMP-9 activity by HT-1080 cells. DL3 (1-O-galloyl-6-O-luteoyl-β-D-glucopyranose) could inhibit MMP-2 activity with IC50=49.63 ?b 11.00 uM and had no cytotoxicity effect for HT-1080 cells.

並列關鍵字

longan seed ； anti-aging ； Matrix metalloproteinases (MMPs)

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