Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan.
Agriculture and Biotechnology Business Division, Toyota Motor Corporation, Toyota-shi, Aichi 471-8571, Japan.
J Agric Food Chem. 2022 Jun 1;70(21):6455-6466. doi: 10.1021/acs.jafc.2c01693. Epub 2022 May 11.
There are numerous cultivars of tea ( L.), but the differences in their anti-hyperglycemic-related effects are largely unknown. The inhibition of the dipeptidyl peptidase (DPP)-IV enzyme plays an essential role in controlling hyperglycemia in diabetes by blocking the degradation of incretin hormones, which is necessary for insulin secretion. In this study, we examined the DPP-IV inhibitory activity of leaf extracts from diverse Japanese green tea cultivars. The inhibitory rates differed among tea extracts. Metabolic profiling (MP), using liquid chromatography-mass spectrometry, of all cultivars revealed compositional differences among cultivars according to their DPP-IV inhibitory capacity. Epigallocatechin-3--(3--methyl)gallate, kaempferol-3--rutinoside, myricetin-3--glucoside/galactoside, and theogallin were newly identified as DPP-IV inhibitors. The bioactivity of a tea extract was potentiated by adding these ingredients in combination. Our results show that MP is a useful approach for evaluating the DPP-IV inhibitory potency of green tea and for determining bioactivity-related ingredients and combinations.
有许多茶树（L.）的栽培品种，但它们在抗高血糖相关效果方面的差异在很大程度上尚不清楚。二肽基肽酶（DPP）-IV 酶的抑制在通过阻断肠降血糖素激素的降解来控制糖尿病中的高血糖中起着至关重要的作用，这对于胰岛素分泌是必需的。在这项研究中，我们检查了来自不同日本绿茶品种的叶提取物的 DPP-IV 抑制活性。茶提取物之间的抑制率不同。使用液相色谱-质谱法（MP）对所有品种进行代谢组学分析，根据它们的 DPP-IV 抑制能力揭示了品种之间的组成差异。表没食子儿茶素-3-O-（3-O-甲基）没食子酸酯、山柰酚-3-O-芸香糖苷、杨梅素-3-O-葡萄糖苷/半乳糖苷和茶红素被新鉴定为 DPP-IV 抑制剂。茶提取物的生物活性通过添加这些成分的组合得到增强。我们的结果表明，MP 是评估绿茶的 DPP-IV 抑制效力以及确定与生物活性相关的成分和组合的有用方法。
