4-octyl itaconate (4-OI) is a cell-permeable itaconate derivative with anti-inflammatory and antioxidant properties. However, its therapeutic potential for oxidative stress-induced liver injury remains unknown. This study investigated the hepatoprotective effects and mechanisms of 4-OI against oxidative damage in in vitro and in vivo models. 4-OI attenuated H₂O₂-induced cytotoxicity, oxidative stress, and mitochondrial dysfunction in L02 and HepG2 cells. Untargeted metabolomics profiling and pathway analysis identified the PI3K/AKT/mTOR and MAPK pathways as key regulators of 4-OI's protective effects. Specifically, 4-OI induced phosphorylation of AKT and ERK1/2, leading to activation of the Nrf2 signaling pathway. Nrf2 upregulated expression of the mitochondrial deacetylase Sirt3, which subsequently alleviated H₂O₂-induced cell injury. In mice, 4-OI reduced acetaminophen (APAP)-induced liver injury as evidenced by attenuated hepatocellular necrosis and decreased serum liver enzymes. It also elevated hepatic expression of Nrf2, Sirt3, p-AKT and p-ERK1/2. Inhibition of AKT, ERK1/2 or Nrf2 blocked the protective effects of 4-OI in vitro, suggesting its antioxidant activity is mediated by activating the Nrf2/Sirt3 pathway via AKT and ERK1/2 phosphorylation. In summary, 4-OI exerted antioxidant and hepatoprotective effects by activating the Nrf2/Sirt3 signaling pathway through AKT and ERK1/2 phosphorylation, which were elucidated using in vitro and in vivo oxidative stress models. This provides novel insights into the mechanisms of 4-OI against oxidative stress-related liver diseases.

4-辛基衣康酸酯(4-OI) 是一种细胞渗透性衣康酸酯衍生物，具有抗炎和抗氧化特性。然而，其对氧化应激引起的肝损伤的治疗潜力仍不清楚。本研究在体外和体内模型中研究了 4-OI 对氧化损伤的保肝作用和机制。 4-OI 减弱了 L02 和 HepG2 细胞中 H ₂ O ₂诱导的细胞毒性、氧化应激和线粒体功能障碍。非靶向代谢组学分析和通路分析确定 PI3K/AKT/mTOR 和 MAPK 通路是 4-OI 保护作用的关键调节因子。具体而言，4-OI 诱导 AKT 和 ERK1/2 磷酸化，从而激活 Nrf2信号通路。 Nrf2 上调线粒体脱乙酰酶 Sirt3 的表达，从而减轻 H ₂ O ₂诱导的细胞损伤。在小鼠中，4-OI 可以减轻对乙酰氨基酚 (APAP) 诱导的肝损伤，肝细胞坏死减弱和血清肝酶降低就证明了这一点。它还提高了 Nrf2、Sirt3、p-AKT 和 p-ERK1/2 的肝脏表达。抑制 AKT、ERK1/2 或 Nrf2 可阻断 4-OI 的体外保护作用，表明其抗氧化活性是通过 AKT 和 ERK1/2 磷酸化激活 Nrf2/Sirt3 途径来介导的。总之，4-OI 通过 AKT 和 ERK1/2 磷酸化激活 Nrf2/Sirt3 信号通路，发挥抗氧化和保肝作用，体外和体内氧化应激模型已阐明这一作用。这为 4-OI 对抗氧化应激相关肝脏疾病的机制提供了新的见解。