Macedo J A, Ferreira L R, Camara L E, Santos J C, Gambero A, Macedo G A, Ribeiro M L
Food Science Department, Faculty of Food Engineering, Campinas State University, P.O. Box 6121, 13083-862 SP, Brazil; Unidade Integrada de Farmacologia e Gastroenterologia (UNIFAG), São Francisco University, Av. São Francisco de Assis 218, Bragança Paulista, SP, Brazil.
Food Science Department, Faculty of Food Engineering, Campinas State University, P.O. Box 6121, 13083-862 SP, Brazil.
Food Chem. 2012 Jul 15;133(2):358-65. doi: 10.1016/j.foodchem.2012.01.041. Epub 2012 Jan 24.
Green tea (Camellia sinensis) is one of the most widely consumed beverages in the world. The cancer chemopreventive qualities of green tea have been well documented. Epigallocatechin gallate (EGCG) is often described as the most potently chemopreventive green tea catechin; however, the low bioavailability of EGCG is a limiting factor for its biological effect. Thus, the aim of this work was to test the chemopreventive potential of green tea extract and EGCG after tannase-mediated hydrolysis. The results showed that the biotransformed compounds retained most of the beneficial properties of the original compounds, and some beneficial properties were improved in the biotransformed compounds. Biotransformation of EGCG decreased its toxicity without affecting its antiproliferative effects. Furthermore, human cells gene expression profiling showed that the biotransformed compounds modulated the expression of several genes related to carcinogenesis. These results demonstrate the benefits of the biotechnological modification of natural food molecules, allowing the improvement of the nutraceutical potential of a beverage as green tea.
绿茶（茶树）是世界上消费最为广泛的饮品之一。绿茶的癌症化学预防特性已有充分记载。表没食子儿茶素没食子酸酯（EGCG）常被描述为最具强效化学预防作用的绿茶儿茶素；然而，EGCG的低生物利用度是其生物学效应的一个限制因素。因此，这项工作的目的是测试经单宁酶介导水解后的绿茶提取物和EGCG的化学预防潜力。结果表明，生物转化后的化合物保留了原始化合物的大部分有益特性，并且一些有益特性在生物转化后的化合物中得到了改善。EGCG的生物转化降低了其毒性，同时不影响其抗增殖作用。此外，人类细胞基因表达谱分析表明，生物转化后的化合物调节了几个与致癌作用相关的基因的表达。这些结果证明了天然食品分子生物技术修饰的益处，使得绿茶这类饮品的营养保健潜力得到提高。
