Qin Si, He Zhilan, Wu Yuanjie, Zeng Chaoxi, Zheng Zhibing, Zhang Haowei, Lv Chenghao, Yuan Yong, Wu Haoren, Ye Jianhui, Liu Zhonghua, Shi Meng
Lab of Food Function and Nutrigenomics, College of Food Science and Technology, Hunan Agricultural University, Changsha, China.
Hunan Tea Group Co. LTD, Changsha, China.
Front Nutr. 2022 Feb 3;9:819980. doi: 10.3389/fnut.2022.819980. eCollection 2022.
Instant dark tea (IDT) is a new product gaining increasing attention because it is convenient and can endow significant health benefit to consumers, which is partially attributed to its high concentration of functional ingredients. However, the molecular mechanism underlying its regulatory effect on hyperlipidaemia is rarely studied. In this study, we performed omics and molecular verification in high-fat diet (HFD)-fed rat, aiming to reveal the mechanism and provide molecular evidence. The results showed that the major bioactive components in IDT were 237.9 mg/g total polysaccharides, 336.6 mg/g total polyphenols, and 46.9 mg/g EGCG. Rats fed with IDT (0.27-0.54 g/kg for 12 weeks) significantly reduced the body weight and TC, TG, LDL-C, blood glucose, and MDA and induced the level of serum HDL-C and also the levels of liver SOD, CAT, GSH-Px, and Nrf2, compared to HFD group. For molecular mechanism study, HIDT feeding had significant impact on the gene expressions of biomarkers in lipogenesis (, and ), lipid oxidation (γ), and glucose glycolysis ( and ) in liver tissue. Moreover, gut microbiome study found that rats fed with IDT dramatically modified the gut microbial species at the family level, such as suppressing the increase abundance of Proteobacteria and Firmicutes induced by HFD. HIDT significantly boosted the relative composition of beneficial bacterium and and decreased the relative abundance of the harmful bacterium and , compared to HFD ( < 0.01). Correlation analysis between microbiome and animal indicators found that seven genera including , and were found as potential biomarkers that were strongly correlated with oxidative stress and metabolism genes. For instance, was significantly correlated with body weight, TG, HDL-C, Nfr2, , and . Collectively, the above data obtained in this study had provided the primary molecular evidence for the molecular mechanism and brought in novel insights based on omics for the regulatory effect of IDT on hyperlipidaemia.
速溶黑茶（IDT）是一种越来越受关注的新产品，因为它方便且能为消费者带来显著的健康益处，这部分归因于其高浓度的功能成分。然而，其对高脂血症调节作用的分子机制鲜有研究。在本研究中，我们对高脂饮食（HFD）喂养的大鼠进行了组学和分子验证，旨在揭示其机制并提供分子证据。结果表明，IDT中的主要生物活性成分是总多糖237.9毫克/克、总多酚336.6毫克/克和表没食子儿茶素没食子酸酯（EGCG）46.9毫克/克。与HFD组相比，用IDT喂养的大鼠（0.27 - 0.54克/千克，持续12周）显著降低了体重、总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL - C）、血糖和丙二醛（MDA），并提高了血清高密度脂蛋白胆固醇（HDL - C）水平以及肝脏超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH - Px）和核因子E2相关因子2（Nrf2）的水平。对于分子机制研究，高剂量IDT喂养对肝脏组织中脂肪生成（ 、 和 ）、脂质氧化（γ）和糖酵解（ 和 ）生物标志物的基因表达有显著影响。此外，肠道微生物组研究发现，用IDT喂养的大鼠在科水平上显著改变了肠道微生物种类，例如抑制了HFD诱导的变形菌门和厚壁菌门丰度的增加。与HFD相比，高剂量IDT显著提高了有益菌 和 的相对组成，降低了有害菌 和 的相对丰度（ < 0.01）。微生物组与动物指标之间的相关性分析发现，包括 、 和 在内的7个属被发现是与氧化应激和代谢基因密切相关的潜在生物标志物。例如， 与体重、TG、HDL - C、Nfr2、 和 显著相关。总体而言，本研究获得的上述数据为分子机制提供了初步的分子证据，并基于组学为IDT对高脂血症的调节作用带来了新的见解。
