Inhibitory effects of oolong tea polyphenols on pancreatic lipase in vitro
Inhibitory effects of oolong tea polyphenols on pancreatic lipase in vitro
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DOI：
10.1021/jf047814
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发表时间：
2005-06-01
影响因子：
6.1
通讯作者：
Kiso, Y
中科院分区：
文献类型：
--
作者：
Nakai, M;Fukui, Y;Kiso, Y
研究了从茶叶中分离的54种多酚对14种胰脂肪酶的抑制活性。胰脂肪酶是肠道脂肪吸收的关键酶。（-）-表没食子儿茶素3-o -没食子儿茶素I （EGCG）是绿茶中主要的多酚之一，对脂肪酶有抑制作用，IC50为0.349 μ m。(-)-表没食子儿茶素-3,5-二二酸黄烷-3-醇双二酸酯对脂肪酶的抑制活性比(-)-表没食子儿茶素，(+)-没食子儿茶素，(+)-表没食子儿茶素，(-)-表没食子儿茶素的IC50为0.098 μ m。14株对胰脂肪酶活性为0或最低（IC50 ~ 20 μ M）。这些数据表明，该结构中没食子酰部分的存在是增强胰脂肪酶抑制所必需的。众所周知，在乌龙茶的生产过程中，黄烷-13-醇是通过多酚氧化酶和/或加热聚合而成的。乌龙茶中典型的乌龙茶素A、B和乌龙茶素3′- o -没食子酸酯表现出较强的抑制活性，其IC50值分别为0.048、0.108和0.068 μ M，甚至高于EGCG。以乌龙茶提取物为原料制备了A乌龙茶聚合多酚（OTPP），通过制备高效液相色谱法有效地去除了零活性和低活性的黄烷-3-醇单体。凝胶渗透色谱法测得OTPP的重量-平均分子量（Mw）和数量-平均分子量（Mn）分别为2017和903。OTPP对胰脂肪酶的抑制作用（IC50 = 0.28 μ g/mL）是单宁酶处理的OTPP （IC50 = 1.38 μ g/mL）的5倍。这些数据表明，在它们的化学结构中存在没食子酰基团和/或黄烷-3-醇的聚合是增强胰腺A脂肪酶抑制所必需的。
Fifty-four polyphenols isolated from tea leaves were evaluated for their inhibitory activities against 14 pancreatic lipase, the key enzyme of lipid absorption in the gut. (-)-Epigallocatechin 3-O-gallate I (EGCG), which is one of major polyphenols in green tea, showed lipase inhibition with an IC50 Of 0.349 mu M. Moreover, flavan-3-ol digallate esters, such as (-)-epigallocatechin-3,5-digallate, showed 14 higher activities of inhibition on lipase with an IC50 of 0.098 mu M. On the other hand, nonesterified flavan-3-ols, such as (+)-catechin, (-)-epicatechin, (+)-gallocatechin, and (-)-epigallocatechin, 14 showed zero and/or the lowest activities against pancreatic lipase (IC50 > 20 mu M). These data suggested that the presence of galloyl moieties within the structure was required for enhancement of pancreatic lipase inhibition. It is well-known that flavan-13-ols are polymerized by polyphenol oxidase and/or heating in a manufacturing process of oolong tea. Oolonghomobisflavans A and B and oolongtheanin 3'-O-gallate, which are typical in oolong tea leaves, showed strong inhibitory activities with IC50 values of 0.048, 0.108, and 0.068 mu M, respectively, even higher than that of EGCG. The A oolong tea polymerized polyphenols (OTPP) were prepared for the assay from oolong tea extract, from which the preparation effectively subtracted the zero and/or less-active monomeric flavan-3-ols by preparative high-performance liquid chromatography. The weight-average molecular weight (Mw) and number-average molecular-weight (Mn) values of OTPP were 2017 and 903, respectively, by using gel permeation choromatography. OTPP showed a 5-fold stronger inhibition against pancreatic lipase (IC50 = 0.28 mu g/mL) by comparison with that of the tannase-treated OTPP (IC50 1.38 mu g/mL). These data suggested that the presence of galloyl moieties within their chemical structures and/or the polymerization of flavan-3-ols were required for enhancement of pancreatic A lipase inhibition.