Mechanism of Total Saponin of Astragali Radix and Total Alkaloids of Nelumbinis Folium Against Hyperlipidemia Based on PPARγ/LXRα/ABCG1 Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the effect of the combination of total saponin of Astragali Radix-total alkaloids of Nelumbinis Folium on reversal cholesterol transport （RCT） in hyperlipidemia rats， and to discuss its mechanism. MethodSixty SD rats were randomly divided into control group， high-fat diet group， total saponin of Astragali Radix-total alkaloids of Nelumbinis Folium low （17 mg·kg-1+40 mg·kg-1）， middle （34 mg·kg-1+80 mg·kg-1）， high dose （68 mg·kg-1+160 mg·kg-1） groups and simvastatin （2.1 mg·kg-1） group， with 10 mice in each group. The Hyperlipidemia model was duplicated by feeding rats with a high-fat diet for 6 weeks. From the 3rd week， except for the control group and the high-fat diet group given distilled water， other groups were given corresponding drugs intragastric treatment for 4 weeks. The changes in blood lipid and liver function of rats were detected by an automatic biochemical analyzer. Hematoxylin-eosin （HE） and oil red O staining were used to observe the pathological morphological changes and steatosis of rat liver tissue. The contents of total cholesterol （TC） and total bile acid （TBA） in rat liver tissue and feces were determined by a semi-automatic biochemical analyzer. The mRNA and protein expression levels of peroxisome proliferators-activated receptors γ （PPARγ）， liver X receptors α （LXRα）， ATP-binding cassette transporter G1 （ABCG1） and cholesterol 7α-hydroxylase （CYP7A1） in rat liver tissue were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultCompared with the control group， the contents or activities of TC， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， TBA， aspartate aminotransferase （AST）， alanine aminotransferase （ALT） in serum were significantly increased （P<0.01）， and the contents of high-density lipoprotein cholesterol （HDL-C） in the high-fat diet group were significantly decreased （P<0.01）. The hepatocyte was clearly swollen like ballooning degeneration， with a lot of fat vacuoles and red fat droplets. The contents of TC and TBA in liver tissue and feces were significantly increased （P<0.01）， and the mRNA and protein expression levels of PPARγ， LXRα， ABCG1， and CYP7A1 in liver tissue were significantly decreased （P<0.01）. Compared with the high-fat diet group， the contents or activities of TC， TG， LDL-C， TBA， AST， and ALT in the serum of rats in administered groups were significantly decreased （P<0.01）， while the content of HDL-C was significantly increased （P<0.01）. Hepatocyte swelling was significantly reduced， and the ballooning degeneration， fat vacuoles， and red lipid droplets in liver tissue were significantly decreased. The contents of TC and TBA in liver tissue were significantly decreased （P<0.05， P<0.01）， and the contents of TC and TBA in feces were significantly increased （P<0.05， P<0.01）. The mRNA and protein expression levels of PPARγ， LXRα， ABCG1， and CYP7A1 in liver tissue were significantly increased （P<0.05， P<0.01）. ConclusionTotal saponin of Astragali Radix-total alkaloids of Nelumbinis Folium has a positive effect on the prevention and treatment of hyperlipidemia rats， and its mechanism may be related to the activation of PPARγ/LXRα/ABCG1 signaling pathway and regulation of RCT.