背景:非酒精性脂肪性肝病(NAFLD),以肝脏脂肪变性和肝细胞损伤为特征,是肥胖引起的代谢失调,几乎没有可用的治疗选择。线粒体功能的增强被认为是NALFD的有效治疗。不饱和脂肪酸(UFA)已被证明对代谢综合征疾病,如高脂血症,冠状动脉疾病和心血管疾病。刺梨种子油(ORRT)的不饱和脂肪酸含量高,质量高。然而,到目前为止,尚未报道ORRT对NALFD的影响。
目的:本研究旨在评价ORRT对NAFLD的体内外保护作用及其分子机制。
方法:有益效果,特别是改善线粒体功能,并在体内和体外研究了ORRT治疗NAFLD的潜在机制。通过甘油三酯(TG)测定脂质水平,总胆固醇(TC),和油红O染色。通过检测抗氧化酶活性来评估氧化应激和炎症,MDA含量,和ELISA测定。血TG,TC,在HFD小鼠中测量HDL-c和LDL-c水平。蛋白质印迹分析用于确定参与脂肪酸氧化的蛋白质的水平,氧化代谢,线粒体生物发生和功能。通过JC-1染色测量线粒体膜电位水平,以测试ORRT对线粒体功能的影响。GW6471(PPARα抑制剂)用于证实PPARα与PGC-1α之间的关系。
结果:ORRT通过减少脂质积累显著抑制NAFLD进展,氧化应激和炎症反应。此外,ORRT上调产热相关基因表达,如解偶联蛋白1(UCP1)和p38丝裂原活化蛋白激酶(p38MAPK)。结果表明,参与脂肪酸氧化的关键基因的表达(例如,CPT-1α,ACADL,PPARα)和线粒体生物发生和功能(例如,TFAM,NRF1,PGC-1α,和COXIV)显著增加。连同观察到的MMP改善,这些发现提示ORRT激活了线粒体氧化途径.此外,GW6471抑制ORRT促进PGC-1α的表达,CPT-1α,和ACADL。总之,ORRT具有通过PPARα/PGC-1α信号通路阻止脂质积累的潜力,它可以被开发为一种天然的健康促进油对抗NAFLD。
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis and hepatocyte injury, is an obesity-induced metabolic dysregulation with few available therapeutic options. Enhancement of the mitochondrial function was considered as an effective treatment for NALFD. Unsaturated fatty acids (UFAs) have been shown to have beneficial effects on metabolic syndrome disease such as hyperlipidemia, coronary artery disease and cardiovascular diseases. The seed oil of Rosa roxburghii Tratt (ORRT) was of high quality in terms of its high amount of unsaturated fatty acids. However, the effects of ORRT on NALFD have not been reported so far.
OBJECTIVE: The study aimed to evaluate the protective effects and molecular mechanism of ORRT for the treatment of NAFLD in vivo and in vitro.
METHODS: The beneficial effects, especially improving the mitochondrial function, and the potential mechanism of ORRT on NAFLD were studied both in vivo and in vitro. Lipid levels were determined by triglyceride (TG), total cholesterol (TC), and Oil Red O staining. Oxidative stress and inflammation were assessed by detecting antioxidant enzyme activity, MDA content, and ELISA assay. Blood TG, TC, HDL-c and LDL-c levels were measured in HFD mice. Western blot analyses were used to determine the levels of the protein involved in fatty acid oxidation, oxidative metabolism, and mitochondria biogenesis and function. The mitochondrial membrane potential level was measured by JC-1 staining to teste the effect of ORRT on mitochondrial function in vitro. GW6471 (inhibitor of PPARα) was used to confirm the relationship between PPARα and PGC-1α.
RESULTS: ORRT significantly restrained NAFLD progression by attenuating lipid accumulation, oxidative stress and inflammatory response. Furthermore, ORRT upregulated thermogenesis-related gene expressions, such as uncoupling protein 1 (UCP1) and p38 mitogen-activated protein kinase (p38 MAPK). The results showed that the expression of key genes involved in fatty acid oxidation (e.g., CPT-1α, ACADL, PPARα) and in mitochondrial biogenesis and function (e.g., TFAM, NRF1, PGC-1α, and COX IV) was significantly increased. Together with the observed MMP improvement, these findings suggested that ORRT activated the mitochondrial oxidative pathway. Additionally, GW6471 inhibited the ORRT on promoting the expression of PGC-1α, CPT-1α, and ACADL. In conclusion, ORRT possessed the potential to prevent lipid accumulation via the PPARα/PGC-1α signaling pathway, which could be developed as a natural health-promoting oil against NAFLD.