Hypolipidemic Effect of Puerarin and Underlying Mechanism Investigation

Abstract

Excessive intake of fat in the diet is one of the main reasons leading to hyperlipidaemia, which will result in many diseases that endanger the human health. Puerarin, which is extracted from the dry roots of the legume plant Radix Puerariae, has been reported to be able to improve the regeneration capability of liver cells, recover the normal liver functions, and prevent the accumulation of fat in the liver. However, research on the regulation of blood lipids has never been referred. In this paper, decrease of the blood lipids in rats by puerarin and the underlying mechanism have been thoroughly discussed. Hyperlipidaemia models were established by feeding the rats with high-fat diet, to which puerarin (10mg/kg, 20mg/kg and 40mg/kg) was then given continuously for 15 days by gavage, and blood indexes of the rats were tested and shown as follows: Puerarin could reduce the serum TC, TG and LDL-C values (P<0.05) and elevate the HDL-C values (P<0.05), which was thus demonstrated to exhibit significant hypolipidemic activity. Total RNA of the rat livers of the group treated with 400mg/kg of puerarin was extracted, and cDNA library was constructed utilizing mag-bind oligo (dT) enriched mRNA. Gene sequencing was carried out, the resulting data were assessed and their saturation was also analyzed. Besides, screening, cluster analysis of expression patterns, GO functional significant enrichment analysis and PATHWAY significant enrichment analysis for the differential gene expressions were performed. Gene expression profiling exhibited that 780 gene levels of the control and hyperlipidaemia model groups changed, in which 525 genes were up-regulated, and 255 genes were down-regulated. Meanwhile, 495 gene levels of the model group changed compared to those of the puerarin groups, in which 72 genes were up-regulated, 423 genes were down-regulated, and the number of the changed genes both involved was 163. Moreover, pathway of the fatty acid metabolism of the most significant enriched GO term was most closely related to the blood lipid metabolism in the differentially expressed genes. In this pathway, alcohol dehydrogenase 6 in the fatty alcohol cycle was down-regulated by puerarin. As a result, puerarin reduced the generation of fatty acids, regulated the entire fatty acid metabolism, and lowered the blood lipids eventually.