Liang Xiao-Yu, Hong Fen-Fang, Yang Shu-Long
Department of Physiology, College of Medicine, Nanchang University, Nanchang, 330006, People's Republic of China.
Experimental Teaching Center, Nanchang University, Nanchang, 330031, People's Republic of China.
Diabetes Metab Syndr Obes. 2021 Apr 28;14:1871-1883. doi: 10.2147/DMSO.S304817. eCollection 2021.
Non-alcoholic fatty liver disease (NAFLD) is the main form of chronic liver disease in the world. Astragaloside IV (ASIV) has been tested in experimental models of different diseases. The purpose of this study was to evaluate the effect and protective mechanism of ASIV on NAFLD.
Lipopolysaccharide (LPS)- and palmitate acid (PA)-induced RAW264.7 cells and LO2 cells were used as a NAFLD model. The mice NAFLD model was evaluated by hematoxylin-eosin staining (HE staining), and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Liver lipid metabolism was evaluated by triglyceride (TG) and total cholesterol (TC) kits and oil red O staining. Oxidative stress indicators were examined through biochemical methods. Inflammatory factors were explored through enzyme-linked immuno sorbent assay (ELISA), real-time quantitative PCR and oxidative stress indicator kits. The expression levels of 5-LO (5-lipoxygenase) and leukotriene A4 hydrolase (LTA4H) were checked by real-time quantitative PCR and Western blotting. Apoptosis was detected by Annexin V-FITC/PI cell apoptosis detection kit.
Our results showed that in vivo ASIV significantly reduced liver tissue damage, and serum AST, ALT and serum TG levels in NAFLD mice. In vitro, ASIV reduced cell supernatant TG and TC content increased by PA treatment, and significantly decreased the accumulation of intracellular lipid droplets induced by PA treatment. Additionally, ASIV reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and restored glutathione peroxidase (GSH-Px) levels in PA-treated LO2 cell supernatant. Furthermore, ASIV inhibited the production of proinflammatory cytokines (IL-6 and TNF-α) in RAW264.7 cells induced by LPS. We also found that ASIV downregulated the expression of 5-LO and LTB4 (leukotriene B4) in NAFLD mice. Moreover, ASIV restored apoptotic protein (Bax and Bcl-2) expression in PA-treated LO2 cells.
ASIV may reduce liver steatosis, hepatocyte oxidative stress and apoptosis, and decrease liver inflammation, thereby attenuating the progression of NAFLD and thus might be of therapeutic interest.
非酒精性脂肪性肝病（NAFLD）是全球慢性肝病的主要形式。黄芪甲苷IV（ASIV）已在不同疾病的实验模型中进行了测试。本研究的目的是评估ASIV对NAFLD的作用及保护机制。
将脂多糖（LPS）和棕榈酸（PA）诱导的RAW264.7细胞和LO2细胞用作NAFLD模型。通过苏木精-伊红染色（HE染色）、天冬氨酸转氨酶（AST）和丙氨酸转氨酶（ALT）水平评估小鼠NAFLD模型。通过甘油三酯（TG）和总胆固醇（TC）试剂盒以及油红O染色评估肝脏脂质代谢。通过生化方法检测氧化应激指标。通过酶联免疫吸附测定（ELISA）、实时定量PCR和氧化应激指标试剂盒探索炎症因子。通过实时定量PCR和蛋白质免疫印迹法检测5-脂氧合酶（5-LO）和白三烯A4水解酶（LTA4H）的表达水平。使用膜联蛋白V-异硫氰酸荧光素/碘化丙啶（Annexin V-FITC/PI）细胞凋亡检测试剂盒检测细胞凋亡。
我们的结果表明，在体内，ASIV显著降低了NAFLD小鼠的肝组织损伤、血清AST、ALT和血清TG水平。在体外，ASIV降低了PA处理导致的细胞上清液TG和TC含量，并显著减少了PA处理诱导的细胞内脂滴积累。此外，ASIV降低了PA处理的LO2细胞上清液中的活性氧（ROS）和丙二醛（MDA）水平，并恢复了谷胱甘肽过氧化物酶（GSH-Px）水平。此外，ASIV抑制了LPS诱导的RAW264.7细胞中促炎细胞因子（IL-6和TNF-α）的产生。我们还发现，ASIV下调了NAFLD小鼠中5-LO和白三烯B4（LTB4）的表达。此外，ASIV恢复了PA处理的LO2细胞中凋亡蛋白（Bax和Bcl-2）的表达。
ASIV可能减轻肝脏脂肪变性、肝细胞氧化应激和细胞凋亡，并减轻肝脏炎症，从而减缓NAFLD的进展，因此可能具有治疗意义。
