基于肝基因表达谱分析的黄芪及其拆分组分对脾虚水湿不化大鼠脂质代谢影响的机制研究

Mechanism of the effect of Radix Astragali and its separated components on the lipid metabolism of rats with syndrome of dampness retention due to spleen deficiency based on whole liver genome expression

目的:探讨黄芪及其拆分组分对脾虚水湿不化大鼠肝脏脂质代谢影响的分子机制。方法:采用高脂低蛋白饮食+负重游泳复合因素诱导6周,建立脾虚水湿不化大鼠模型,造模后给予黄芪及其拆分组分(水提物、黄酮、皂苷、多糖)干预2周,检测肝脏的病理变化,并通过基因芯片检测黄芪及其拆分组分对脾虚水湿不化大鼠脂质代谢调节通路的影响。结果:与正常对照组相比,脾虚水湿不化大鼠肝脏体积变大,肝细胞肿胀呈空泡样变,PPARα信号通路基因fabp4、olr1、cpt1b下调,me1、cyp7a1和aqp7基因上调。与脾虚水湿不化大鼠相比,黄芪及其拆分组分组空泡样变肝细胞数目明显减少,细胞肿胀程度减轻。与脾虚水湿不化大鼠相比,黄芪水煎液组cyp7a1基因下降,olr1和fabp4基因升高,黄芪黄酮组fabp4基因升高,aqp7基因下降,黄芪多糖组cyp7a1基因下降,olr1和cpt1b基因升高;黄芪水煎液组亚油酸代谢通路pla2 g4a、pla2 g2d、cyp2c12、loc687842升高,黄芪皂苷组pla2 g4a、pla2 g2d和loc687842升高,黄芪多糖组cyp2c12和loc687842升高。结论:黄芪及其拆分组分(黄酮、皂苷和多糖)可以不同程度的改善脾虚水湿不化大鼠的肝脏形态和功能,其机制可能与调节肝脏脂质代谢PPARα信号通路(关键基因为me1、cyp7a1、aqp7、fabp4、olr1、cpt1b)和亚油酸代谢通路(关键基因为pla2 g4a、pla2 g2d、cyp2c12、loc687842)有关,黄芪各拆分组分中多糖组分为调节脂代谢的主要物质。

Objective： To explore the molecular mechanism of the effect of Radix Astragali and its separated components on the lipid metabolism of rats with syndrome of dampness retention due to spleen deficiency. Methods： Rats with syndrome of dampness retention due to spleen deficiency were induced by complex factors of high fat and low protein diet,loading swimming for six weeks. And then,Radix Astragali and its separated components were administered to corresponding groups for two weeks,both pathological changes of the liverand gene expression changes related to lipid metabolism regulation were tested by using gene chip. Results： Morphological changes of the larger liver and bubble-like swelling of liver cells were detected in rats with syndrome of dampness retention due to spleen deficiency. Compared with the normal control group,genes of the PPARα pathway including fabp4,olr1 and cpt1 b were down-regulated; me1,cyp7a1 and aqp7 were up-regulated in rats with syndrome of dampness retention due to spleen deficiency. Compared with the model control group,the number and degree of bubble-like swelling of liver cells in Radix Astragali and its separated components groups were decreased. Compared with the model control group,cyp7a1 was downregulated,olr1 and fabp4were up-regulated in rats of the decoction liquid of Radix Astragali group; aqp7 was down-regulated and fabp4 was up-regulated in rats of Astragali flavone group; cyp7a1 was down-regulated,olr1 and cpt1bwere up-regulated in rats of Astragalus polysaccharide group. Compared with the model control group,genes of the Linoleic acid metabolic pathway including pla2g4 a,pla2 g2 d,cyp2c12 and loc687842wereup-regulated in rats of the decoction liquid of Radix Astragali group,pla2 g4 a,pla2 g2 d,cyp2c12 and loc687842 were up-regulated in rats of Astragali saponin group,cyp2c12 and loc687842 were also up-regulated in rats of Astragalus polysaccharide group. Conclusion： Radix Astragali and its separated components（ including Astragali flavones,Astragali saponin and Astragalus polysaccharide） obviously improved the abnormal morphology of the livers of rats with syndrome ofdampness retention due to spleen deficiency,the mechanism of which may be the regulation of key genes of PPARα and Linoleic acid metabolic pathway. The key genes of PPARα pathway were me1,cyp7a1,aqp7,fabp4,olr1 and cpt1 b,and the key genes of Linoleic acid metabolic pathway were pla2 g4 a,pla2 g2 d,cyp2c12 and loc687842. The Astragalus polysaccharide was proved to be the main substance in the regulation of lipid metabolism.