Study Of The Mechanism Of Strengthening Spleen And Removing Dampness Of Radix Astragali And Its Separated Components Based On Whole Genome Expression

Objective: To explore the role of spleen in water metabolism in rats with syndrome of dampness retention due to spleen deficiency induced by complex factors with whole genome expression chip To study the property and flavor pharmacological effects of Astragalus and its separated components(water extract, flavonoids, saponins and polysaccharides) based on the hypothesis of property and flavor, And to study the effects of Astragalus and its separated components on whole genome expression of liver in rats with syndrome of dampness retention due to spleen deficiency with gene chip, and then to explore the material basis and the molecular mechanism behind those effects.Methods: The TCM syndrome model of dampness retention due to spleen deficiency was induced in rats with complex factors of high fat and low protein diet, loading swimming for six weeks, and evaluated with PLS method to screen the specific indicators and to test its reliability. After the TCM syndrome model successfully induced, radix Astragali and its separated components were administered to the rats for two weeks in different groups. Ordinary situation, serum protein, serum fat, water loading index, the morphology and function of the liver were tested to study the property and flavor pharmacological effects. The differential expression genes manifested in different groups with whole genome expression chip were analyzed with Gene Ontology and KEGG pathway, to explore the material basis and the molecular mechanism. Several of genes were selected to test the accuracy of results by PCR.Results: After six weeks of induction, rats in model group showed specific signsof dampness retention due to spleen deficiency. The rats in the model group appeared weight loss, accidie, squinting, camponotus signs, weakened gastrointestinal function, decreased serum protein, the disorder of blood lipid, and the dysfunction of water transport, indicating the successful establishment of the rat model. The model was evaluated as successful one by PLS and Gas, LDL-C, and general status score, weight, total cholesterol, locomotor activity, and water loading index were indicated as the important variables. All of Radix Astragali separated components obviously improved the ordinary syndromes elevated protein levels, regulated the lipid metabolism, promoted the circulation of water, and improved the abnormal morphology and function of the liver, which may be the "warm property and sweet flavor" effect of Astragalus. And Astragalus polysaccharide was proved to be the best among the separated components. According to the results of gene chip, genes of ion and water transportion, glycolytic/gluconeogenic pathway, the glutathione metabolism pathway, PPAR signaling pathway and histidine metabolism were abnormally expressed in rats with syndrome of dampness retention due to spleen deficiency. Radix Astragali and its separated components can regulate and improve the expression of genes of model rats, by the mechanisms of ion and water channels, glycolytic/gluconeogenic pathway, glutathione metabolism pathway, PPAR signaling pathway, histidine metabolism, glucose metabolism of linoleic acid, galactose metabolism and arginine and proline. And Astragalus polysaccharide, as the main component of Radix Astragali, also proved to be the best. The results of RT-PCR were consistent with the gene chip results, indicating reliability of the gene chip.Conclusion: Abnormal ion and water transport, the lack of energy, the weakened antioxidant defense, "Yin Sheng Yang Xu," may be the molecular mechanism of dampness retention due to spleen deficiency. Radix Astragali decoction and its separated components can improve abnormal ion and water transport, the lack of energy, the weakened antioxidant defense, and Astragalus polysaccharide may be the substance contributed mostly. According to the hypothesis of property and flavor, Astragalus is warm and able to promote the body’s energy and related metabolism, the characteristics of which are the enhanced glycolytic pathway and lipid oxidation, gluconeogenesis and amino acid metabolism inhibition.