Institute of Digestive Diseases, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China.
Teaching Experiment Center, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
BMC Complement Med Ther. 2022 Aug 9;22(1):213. doi: 10.1186/s12906-022-03697-9.
Salvia-Nelumbinis naturalis (SNN), the extract of Chinese herbal medicine, has shown effects on NAFLD. This study aims to explore the underlying mechanism of SNN for regulating the lipid metabolism disorder in NAFLD based on the SIRT1/AMPK signaling pathway.
Male C57BL/6J mice fed with a high-fat diet (HFD) were used to establish the NAFLD model. Dynamic changes of mice including body weight, liver weight, serological biochemical indexes, liver histopathological changes, and protein level of AMPK and SIRT1 were monitored. After18 weeks, SNN treatment was administrated to the NAFLD mice for another 4 weeks. Besides the aforementioned indices, TC and TG of liver tissues were also measured. Western blot and quantitative RT-PCR were used to detect the expression and/or activation of SIRT1 and AMPK, as well as the molecules associated with lipid synthesis and β-oxidation. Furthermore, AML12 cells with lipid accumulation induced by fatty acids were treated with LZG and EX527 (SIRT1 inhibitor) or Compound C (AMPK inhibitor ) to confirm the potential pharmacological mechanism.
Dynamic observation found the mice induced by HFD with gradually increased body and liver weight, elevated serum cholesterol, hepatic lipid accumulation, and liver injury. After 16 weeks, these indicators have shown obvious changes. Additionally, the hepatic level of SIRT1 and AMPK activation was identified gradually decreased with NAFLD progress. The mice with SNN administration had lower body weight, liver weight, and serum level of LDL-c and ALT than those of the NAFLD model. Hepatosteatosis and hepatic TG content in the liver tissues of the SNN group were significantly reduced. When compared with control mice, the NAFLD mice had significantly decreased hepatic expression of SIRT1, p-AMPK, p-ACC, ACOX1, and increased total Acetylated-lysine, SUV39H2, and SREBP-1c. The administration of SNN reversed the expression of these molecules. In vitro experiments showed the effect of SNN in ameliorating hepatosteatosis and regulating the expression of lipid metabolism-related genes in AML12 cells, which were diminished by EX527 or Compound C co-incubation.
Taken together, the SIRT1/AMPK signaling pathway, involved in hepatic lipid synthesis and degradation, plays a pivotal role in the pathogenesis of NAFLD development. The regulation of SIRT1/AMPK signaling greatly contributes to the underlying therapeutic mechanism of SNN for NAFLD.
中药丹参提取物（SNN）对非酒精性脂肪性肝病（NAFLD）有一定的疗效。本研究旨在探讨 SNN 通过 SIRT1/AMPK 信号通路调节 NAFLD 脂质代谢紊乱的作用机制。
采用高脂饮食（HFD）喂养雄性 C57BL/6J 小鼠建立 NAFLD 模型。动态监测小鼠体重、肝重、血清生化指标、肝组织病理变化及 AMPK 和 SIRT1 蛋白水平。18 周后，NAFLD 小鼠给予 SNN 治疗 4 周。除上述指标外，还检测肝组织 TC 和 TG。Western blot 和 qRT-PCR 检测 SIRT1 和 AMPK 的表达和/或激活，以及与脂质合成和β-氧化相关的分子。此外，用脂肪酸诱导脂滴堆积的 AML12 细胞用 LZG 和 EX527（SIRT1 抑制剂）或 Compound C（AMPK 抑制剂）处理，以确认潜在的药理学机制。
动态观察发现，HFD 诱导的小鼠体重和肝重逐渐增加，血清胆固醇升高，肝内脂质堆积，肝损伤。16 周后，这些指标变化明显。此外，随着 NAFLD 的进展，SIRT1 和 AMPK 激活的肝水平逐渐降低。给予 SNN 的小鼠体重、肝重、血清 LDL-c 和 ALT 水平低于 NAFLD 模型组。SNN 组肝组织肝组织 steatosis 和肝组织 TG 含量明显降低。与对照组相比，NAFLD 小鼠肝组织 SIRT1、p-AMPK、p-ACC、ACOX1 表达降低，总乙酰化赖氨酸、SUV39H2、SREBP-1c 增加。SNN 处理可逆转这些分子的表达。体外实验表明，SNN 可改善 AML12 细胞 steatosis，并调节脂代谢相关基因的表达，而 EX527 或 Compound C 共孵育可减弱这种作用。
综上所述，参与肝内脂质合成和降解的 SIRT1/AMPK 信号通路在 NAFLD 发病机制中起关键作用。SIRT1/AMPK 信号的调节对 SNN 治疗 NAFLD 的潜在治疗机制有很大贡献。
