Saito Masataka, Saito Kyoko, Kunisaki Naomichi, Kimura Shigeru
Laboratory of Food Science, Kagawa Nutrition University, Chiyoda, Sakado, Saitama 350-0288, Japan.
J Agric Food Chem. 2002 Nov 20;50(24):7169-74. doi: 10.1021/jf025741t.
We have investigated the inhibitory effects of polyphenols from natural products, such as green tea, bilberry, grape, ginkgo, and apple, on rainbow trout gelatinase activities. Gelatinases from the skin, muscle, and blood of rainbow trout contained serine proteinase, metalloproteinase, and other proteinase activities as measured by gelatin zymography. The polyphenols of green tea caused the strong inhibition of some gelatinase activities when compared with those of the other products. This inhibition was quite similar to that of metalloproteinase by ethylenediaminetetraacetic acid, suggesting that the effects of green tea polyphenols on proteinase activities are specific for metalloproteinases. The major catechins of green tea polyphenols were then separated and identified by reverse-phase chromatography to be (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin, (-)-epicatechin gallate, and (-)-epicatechin. The effects of these catechins on gelatinase activities were examined; the most potent inhibitor of metalloproteinase activities was found to be EGCG. These results have indicated that green tea polyphenols including EGCG are useful for regulating metalloproteinase activities of fish meat.
我们研究了天然产物中的多酚，如绿茶、越橘、葡萄、银杏和苹果，对虹鳟鱼明胶酶活性的抑制作用。通过明胶酶谱法测定，虹鳟鱼皮肤、肌肉和血液中的明胶酶含有丝氨酸蛋白酶、金属蛋白酶和其他蛋白酶活性。与其他产品相比，绿茶中的多酚对某些明胶酶活性有强烈的抑制作用。这种抑制作用与乙二胺四乙酸对金属蛋白酶的抑制作用非常相似，表明绿茶多酚对蛋白酶活性的影响对金属蛋白酶具有特异性。然后通过反相色谱法分离并鉴定了绿茶多酚的主要儿茶素为（-）-表没食子儿茶素没食子酸酯（EGCG）、（-）-表没食子儿茶素、（-）-表儿茶素没食子酸酯和（-）-表儿茶素。检测了这些儿茶素对明胶酶活性的影响；发现对金属蛋白酶活性最有效的抑制剂是EGCG。这些结果表明，包括EGCG在内的绿茶多酚可用于调节鱼肉中的金属蛋白酶活性。
