ScopeAcute alcoholic liver injury (AALI), a global health concern, is exacerbated by excessive episodic drinking. L‐theanine (LTA), a compound found in tea leaves, mitigates the AALI‐induced liver oxidative stress and inflammation. However, its relationship with alcohol metabolism and its liver‐protective mechanism remains unexplored.Methods and resultsThis study investigates the protective mechanisms of LTA against AALI in mice. The results demonstrate that LTA mitigates liver tissue damage and reduces the serum levels of aspartate aminotransferase and alanine aminotransferase, and liver levels of triglycerides, malondialdehyde, reactive oxygen species (ROS), tumor necrosis factor‐α, interleukin‐6, and interleukin‐1β. However, LTA enhances the activity of ethanol‐metabolizing enzymes and decreases ethanol and acetaldehyde serum levels. Mechanistically, LTA accelerates alcohol metabolism by upregulating the hepatic expression of ADH6, ALDH1B1, ALDH2, CAT, and ACSS1 mRNA and protein in AALI mice, LTA downregulates the expression of CYP2E1 mRNA and protein and promoting antioxidative activities thus reducing the accumulation of ROS. This attenuated inflammation by inhibiting the phosphorylation of nuclear factor‐kappa B inhibitor alpha (IκBα) and downregulating the hepatic expression of NF‐κB p65, TNF‐α, IL‐1β, IL‐6 mRNA, and protein.ConclusionLTA is a beneficial dietary supplement that protects against AALI by modulating alcohol metabolism and the TNF‐α/NF‐κB pathway.

中文翻译：

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L-茶氨酸对小鼠急性酒精性肝损伤的保护作用及机制


范围急性酒精性肝损伤 （AALI） 是一个全球性的健康问题，发作性过量饮酒会加剧。L-茶氨酸 （LTA） 是一种在茶叶中发现的化合物，可减轻 AALI 诱导的肝脏氧化应激和炎症。然而，它与酒精代谢的关系及其肝脏保护机制仍未得到探索。方法和结果本研究探讨了 LTA 对小鼠 AALI 的保护机制。结果表明，LTA 减轻肝组织损伤并降低血清天冬氨酸转氨酶和丙氨酸转氨酶水平，以及肝脏甘油三酯、丙二醛、活性氧 （ROS）、肿瘤坏死因子 α 、白细胞介素-6 和白细胞介素-1β 水平。然而，LTA 可增强乙醇代谢酶的活性并降低乙醇和乙醛血清水平。从机制上讲，LTA 通过上调 AALI 小鼠肝脏中 ADH6、ALDH1B1、ALDH2、CAT 和 ACSS1 mRNA 和蛋白的表达来加速酒精代谢，LTA 下调 CYP2E1 mRNA 和蛋白的表达并促进抗氧化活性，从而减少 ROS 的积累。这通过抑制核因子-κB 抑制剂 α （IκBα） 的磷酸化和下调 NF-κB p65、TNF-α、IL-1β、IL-6 mRNA 和蛋白质的肝脏表达来减轻炎症。结论LTA 是一种有益的膳食补充剂，通过调节酒精代谢和 TNF-α/NF-κB 通路来预防 AALI。