Mechanism of Astragaloside Ⅳ on db/db Mice with Type 2 Diabetes Mellitus and Non-alcoholic Fatty Liver Disease Based on AMPK Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo study the mechanism of astragaloside Ⅳ （AS Ⅳ） on db/db mice with type 2 diabetes mellitus （T2DM） and non-alcoholic fatty liver disease （NAFLD） based on network pharmacology and experimental validation. MethodA total of 24 db/db mice were randomly divided into four groups： model group， metformin group， and low-dose and high-dose AS Ⅳ groups. Six C57 mice were used as the blank group. The low-dose and high-dose AS Ⅳ groups were given AS Ⅳ of 0.015 and 0.030 g·kg-1 by gavage， and the metformin group was given 0.067 g·kg-1 by gavage. The blank and model groups were given equal volumes of distilled water by gavage. After intragastric administration， fasting blood glucose （FBG） was detected， and an oral glucose tolerance test was performed. Serum lipid level and liver histopathology were detected. The target and enrichment pathway of AS Ⅳ for treating T2DM and NAFLD were predicted by network pharmacology， and the main enrichment pathway was verified by molecular biology techniques. The protein expressions of AMPK， p-AMPK， sterol regulatory element-binding protein-1 （SREBP-1）， and fatty acid synthetase （FAS） in liver tissue were detected by Western blot. ResultCompared with the blank group， the levels of body mass， liver weight coefficient， fasting blood glucose， serum total cholesterol， triglyceride， and low-density lipoprotein cholesterol in mice treated with AS Ⅳ were decreased （P<0.05， P<0.01）. The pathology of liver tissue showed significant improvement in lipid accumulation， and imaging results showed that the degree of fatty liver was reduced after AS Ⅳ therapy. Network pharmacological prediction results showed that vascular endothelial growth factor α （VEGFA）， galactoagglutinin 3 （LGALS3）， serine/threonine kinase B2 （Akt2）， RHO-associated coiled-coil protein kinase 1 （ROCK1）， serine/threonine kinase B1 （Akt1）， signaling and transcriptional activator protein （STAT3）， and messtimal epidermal transformation factor （MET） were key targets in "drug-disease" network. The results from the Kyoto encyclopedia of genes and genomes （KEGG） enrichment showed that the AMP-dependent protein kinase （AMPK） signaling pathway was strongly associated with T2DM and NAFLD. Western blot results showed that compared with the blank group， the expression levels of p-AMPK/AMPK in the model group were significantly down-regulated， while those of SREBP-1 and FAS proteins were significantly up-regulated （P<0.01）. Compared with the model group， the expression levels of p-AMPK/AMPK in the metformin group and high-dose AS Ⅳ group were significantly up-regulated， while those of SREBP-1 and FAS proteins were significantly down-regulated （P<0.05， P<0.01）. ConclusionAS Ⅳ regulates the expression of lipid proteins by activating the AMPK signaling pathway， thereby improving lipid metabolism.