Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, China.
Free Radic Biol Med. 2021 Feb 20;164:1-12. doi: 10.1016/j.freeradbiomed.2020.12.020. Epub 2021 Jan 1.
Non-alcoholic steatohepatitis (NASH) is the progressive stage of non-alcoholic fatty liver disease that may ultimately lead to cirrhosis and liver cancer, and there are few therapeutic options for its treatment. Physalin B (PB), a withanolide isolated from Physalis species (Solanaceae), exhibits a broad spectrum of biological activities, however, the potential role of PB in NASH has not been evaluated. The present study investigated the protective effects of PB against NASH and further elucidated the mechanisms of PB in hepatic autophagy and oxidative stress in vitro and in vivo. We conducted a series of experiments using methionine-choline deficient (MCD) diet induced NASH mice and cultured L02 cells. Serum markers of liver injury, morphology, and the histology of liver tissues were investigated. Western blot assays and quantitative real-time PCR were used to investigate the hepatoprotective effect of PB. PB significantly ameliorated hepatic injury, including hepatic index, transaminase activities, histology, and inflammation in MCD-induced mice. Moreover, PB markedly increased the expression of P62 and the ratio of LC3Ⅱ/Ⅰ in vitro and in vivo. Furthermore, PB promoted the interaction between endogenous KEAP1 and P62, reduced the interaction between KEAP1 and NRF2, activated the nuclear translocation of NRF2 and NRF2 target gene expression, and ultimately attenuated oxidative stress. In addition, knockdown of P62 blocked PB-mediated activation of NRF2 in L02 cells. These results clearly indicated that PB ameliorated NASH by stimulating autophagy and P62-KEAP1-NRF2 antioxidative signaling, suggesting that PB is expected to become a novel therapeutic drug for NASH.
非酒精性脂肪性肝炎（NASH）是一种非酒精性脂肪性肝病的进展阶段，可能最终导致肝硬化和肝癌，而其治疗方法很少。来自茄科（Solanaceae）酸浆属（Physalis）植物的甾体化合物Physalin B（PB）具有广泛的生物活性，但 PB 在 NASH 中的潜在作用尚未得到评估。本研究探讨了 PB 对 NASH 的保护作用，并进一步阐明了 PB 在体外和体内肝自噬和氧化应激中的作用机制。我们使用蛋氨酸-胆碱缺乏（MCD）饮食诱导的 NASH 小鼠和培养的 L02 细胞进行了一系列实验。检测血清肝损伤标志物、肝脏形态和组织学变化。采用 Western blot 检测和实时定量 PCR 检测 PB 的肝保护作用。PB 显著改善了 MCD 诱导的小鼠肝损伤，包括肝指数、转氨酶活性、组织学和炎症。此外，PB 显著增加了 P62 和 LC3Ⅱ/Ⅰ的表达，无论是在体外还是在体内。此外，PB 促进了内源性 KEAP1 和 P62 之间的相互作用，减少了 KEAP1 和 NRF2 之间的相互作用，激活了 NRF2 的核易位和 NRF2 靶基因的表达，最终减轻了氧化应激。此外，P62 的敲低阻断了 PB 在 L02 细胞中介导的 NRF2 激活。这些结果清楚地表明，PB 通过刺激自噬和 P62-KEAP1-NRF2 抗氧化信号通路改善 NASH，提示 PB 有望成为治疗 NASH 的一种新型治疗药物。
