Forester Sarah C, Lambert Joshua D
Department of Food Science, The Pennsylvania State University, University Park, PA, USA.
Department of Food Science, The Pennsylvania State University, University Park, PA, USA ; Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA.
J Funct Foods. 2015 Aug 1;17:183-188. doi: 10.1016/j.jff.2015.05.012.
(-)-Epigallocatechin-3-gallate (EGCG), has been shown to inhibit cancer . EGCG, however, is rapidly methylated by catechol--methyl transferase (COMT), which reduces its cancer preventive efficacy. Tolcapone (TOL), is a clinically-used COMT inhibitor. Here, we examined the effect of TOL on the bioavailability of EGCG in male CF-1 mice. Plasma and tissue levels of EGCG and its methyl metabolites were determined following intragastric administration of EGCG (100 mg/kg), TOL (30 mg/kg), or the combination. In mice treated with EGCG, unmethylated plasma EGCG accounted for 63.4 % of the total. Co-administration of TOL increased this fraction to 87.9 %. In the urine, unmethylated EGCG accounted for 29.2 % of the total, whereas treatment with EGCG plus TOL increased this to 81.8 %. Similar effects were observed in the major organs examined. TOL effectively inhibited the methylation of EGCG . Future studies should examine the cancer preventive effects of the combination.
（-）-表没食子儿茶素-3-没食子酸酯（EGCG）已被证明具有抗癌作用。然而，EGCG会被儿茶酚-O-甲基转移酶（COMT）迅速甲基化，从而降低其防癌功效。托卡朋（TOL）是一种临床使用的COMT抑制剂。在此，我们研究了TOL对雄性CF-1小鼠体内EGCG生物利用度的影响。在分别灌胃给予EGCG（100 mg/kg）、TOL（30 mg/kg）或两者组合后，测定血浆和组织中EGCG及其甲基代谢产物的水平。在给予EGCG的小鼠中，未甲基化的血浆EGCG占总量的63.4%。同时给予TOL可使这一比例增至87.9%。在尿液中，未甲基化的EGCG占总量的29.2%，而给予EGCG加TOL治疗可使其增至81.8%。在所检查的主要器官中也观察到了类似的效果。TOL有效地抑制了EGCG的甲基化。未来的研究应考察两者组合的防癌效果。
