Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China; Lushan Tea Science Research Institute, Jiujiang, Jiangxi, 332000, China.
Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China; National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, 410128, China.
Food Chem Toxicol. 2023 Nov;181:114095. doi: 10.1016/j.fct.2023.114095. Epub 2023 Oct 10.
The protein levels in a diet are correlated with immunity but the long-term intake of excessive protein can compromise various aspects of health. L-theanine regulates immunity and protein metabolism; however, how its regulatory immunity effects under a high-protein diet are unclear. We used proteomics, metabonomics, and western blotting to analyze the effects of diets with different protein levels on immune function in rats to determine the role of L-theanine in immunity under a high-protein diet. The long-term intake of high-protein diets (≥40% protein) promoted oxidative imbalance and inflammation. These were alleviated by L-theanine. High-protein diets inhibited peroxisome proliferator-activated receptor (PPAR)α expression through the interleukin (IL)-6/signal transducer and activator of transcription (STAT)3 pathway and mediated inflammation. L-theanine downregulated anti-fatty acid-binding protein 5 (FABP5), inhibited the IL-6/STAT3 axis, and reduced high-protein diet-induced PPARα inhibition. Therefore, L-theanine alleviates the adverse effects of high-protein diets via the FABP5/IL-6/STAT3/PPARα pathway and regulates the immunity of normally fed rats through the epoxide hydrolase (EPHX)2/nuclear factor-kappa B inhibitor (IκB)α/triggering receptor expressed on myeloid cells (TREM)1 axis.
饮食中的蛋白质水平与免疫力相关，但长期摄入过量蛋白质会损害健康的多个方面。L-茶氨酸调节免疫和蛋白质代谢；然而，在高蛋白饮食下，其调节免疫的作用机制尚不清楚。我们使用蛋白质组学、代谢组学和蛋白质印迹分析了不同蛋白质水平的饮食对大鼠免疫功能的影响，以确定 L-茶氨酸在高蛋白饮食下的免疫作用。长期摄入高蛋白饮食（≥40%蛋白质）会促进氧化失衡和炎症。L-茶氨酸可缓解这些影响。高蛋白饮食通过白细胞介素 (IL)-6/信号转导和转录激活因子 (STAT)3 通路抑制过氧化物酶体增殖物激活受体 (PPAR)α 的表达并介导炎症。L-茶氨酸下调抗脂肪酸结合蛋白 5 (FABP5)，抑制 IL-6/STAT3 轴，并减少高蛋白饮食诱导的 PPARα 抑制。因此，L-茶氨酸通过 FABP5/IL-6/STAT3/PPARα 通路缓解高蛋白饮食的不良影响，并通过环氧水解酶 (EPHX)2/核因子-κB 抑制剂 (IκB)α/髓样细胞表达的触发受体 (TREM)1 轴调节正常喂养大鼠的免疫功能。
