非酒精性脂肪性肝病（NAFLD）正在成为一种全球性流行病，目前还没有有效的治疗方法。NAFLD的特点是肝脏新生脂肪（DNL）增加和脂肪酸氧化（FAO）的补偿增强不足，这扰乱了脂质的平衡。在NAFLD中，脂质代谢主要依赖于代谢重编程。此外，脂质代谢在脂肪生成和FAO之间的转换中起着关键作用，这有利于抗NAFLD疗法。我们最近的研究表明，植物化学物质四氢巴马汀（THP）在肝细胞肝癌（HCC）中具有积极的疗效。然而，目前还不清楚THP的治疗效益主要是延缓肝脂肪变性向HCC的进展。本研究旨在使用体内和体外模型对THP在NAFLD中的药理功能和潜在机制进行系统评估。NAFLD模型使用高脂饮食（HFD）喂养小鼠进行体内实验，以及使用棕榈酸和油酸刺激的体外肝细胞进行体外实验。综合性地进行代谢组学分析、生化指标和计算生物学实验，以全面揭示在治疗NAFLD和AMPK-SREBP-1c-Sirt1信号通路之间的关键联结。肝代谢组学分析显示，THP通过增强FAO和抑制糖酵解、三羧酸循环和尿素循环来改变脂质代谢。基因表达分析显示，THP深度抑制肝脏DNL并促进FAO。THP补充不仅显著减少了体重/肝重增加和血清指标，还改善了肝脂肪变性。同时，在THP补充后观察到了体内和体外的脂质毒性损害，从而保护免受肥胖引起的损伤。代谢表型实验显示，THP促进了脂肪变性细胞中由糖酵解抑制到FAO增强的转换，从而重编程脂质代谢。在机制上，THP通过激活AMPK-SREBP-1c-Sirt1轴信号加速脂质氧化。应用分子对接技术结合表面等离子共振和细胞热稳定性分析蛋白靶位点的结合，以及siRNA实验，证实AMPKα是THP的直接分子靶点。总之，THP通过在NAFLD中通过AMPK-SREBP-1c-Sirt1通路切换脂质代谢，改善了肝脂肪变性。本研究为对抗NAFLD中肝脂肪变性的治疗提供了有吸引力的植物化学成分。版权所有 © 2023 Elsevier GmbH。保留所有权利。

Nonalcoholic fatty liver disease (NAFLD) is becoming a global epidemic without effective treatment currently available. NAFLD is characterized by an increase in hepatic de novo lipogenesis (DNL) and inadequate compensatory enhancement in fatty acid oxidation (FAO), which disturbs lipid homeostasis. In NAFLD, lipid metabolism relies heavily on metabolic reprogramming. Moreover, lipid metabolism plays an essential role in switching between lipogenesis and FAO, which is beneficial for the anti-NAFLD therapy. Our recent study demonstrated that the phytochemical tetrahydropalmatine (THP) has positive efficacy in hepatocellular carcinoma (HCC). However, it remains unclear whether the therapeutic benefits of THP are primarily due to delaying the progression of hepatic steatosis to HCC.This work aimed to systemically evaluate the pharmacological functions and underlying mechanisms of THP in NAFLD using both in vitro and in vivo models.NAFLD models were established using high-fat diet (HFD)-fed mice in vivo and palmitic acid- and oleic acid-challenged hepatocytes in vitro. Metabonomics analysis concomitant with biochemical indices and computational biology assays were performed comprehensively to reveal the key link between the treatment of NAFLD and the AMPK-SREBP-1c-Sirt1 signaling axis.Hepatic metabolomics analysis revealed that THP altered lipid metabolism by enhancing FAO and inhibiting glycolysis, tricarboxylic acid cycle, and urea cycle in HFD-fed mice. Analysis of gene expression showed that THP profoundly suppressed hepatic DNL and promoted FAO. THP supplementation not only significantly decreased body/liver weight gain and serum indices but also ameliorated hepatic steatosis. Simultaneously, impaired lipotoxicity was observed in vivo and in vitro after THP supplementation, protecting against steatosis-driven injury. Metabolic phenotype assays showed that THP promoted switching from glycolysis inhibition to FAO enhancement in steatotic cells, resulting in reprogramming lipid metabolism. Mechanistically, THP accelerated lipid oxidation by activating AMPK-SREBP-1c-Sirt1 axis signaling. Applying molecular docking combined with surface plasmon resonance and cellular thermal shift assay target engagement, as well as siRNA assays, AMPKα was confirmed as a direct molecular target of THP.In summary, THP ameliorates hepatic steatosis in NAFLD by switching lipid metabolism via the AMPK-SREBP-1c-Sirt1 pathway. This work provides an attractive phytochemical component for therapy against hepatic steatosis in NAFLD.Copyright © 2023 Elsevier GmbH. All rights reserved.