The Study On Screening Biomarkers Of Yin-Deficiency-Heat Syndrome And The Treatment Mechanism Of Zhibai Dihuang Granule Based On Metabolomics

Background:The heat syndrome is a concept of traditional Chinese medicine(TCM)which is usually triggered by some external precipitating factors like high stress in life,inappropriate diet,insufficient sleep and lack of water,as well as genetic factors.Clinical manifestations of the heat syndrome include gingivitis,oral ulcer,sore throat,hard stools,restless fever,etc.The syndrome does not result in organic lesions and pose a threat to life,but is a big trouble for people with these symptoms.It is divided into two major types,the excess fire and the deficiency fire.The latter is caused by overstrain or eating too much food with hot nature,leading to viscera function disorder and the consumption of yin-fluid.The yin deficiency causes endogenous heat and the deficiency fire arises.The deficiency fire consists of Qi-Deficiency-Heat and Yin-Deficiency-Heat.Zhibai Dihuang Granule is kind of Chinese patent medicine which is used in the treatment of Yin-Deficiency-Heat(YDH)Syndrome.While TCM is popular among Chinese people,it is questioned by Western medicine for its unique theory system.The heat syndrome is a common pathological state bothering Western medicine a lot.The therapeutic method in TCM,nourishing yin to lessen fire,has a notable curative effect on YDH.However,there are few studies on the biological mechanism of YDH and the treatment mechanism of Zhibai Dihuang Granule.Objective:The current study aims to investigate the metabolic profiling in the serum of YDH rats based on non-targeted metabolomics,screen differentially expressed metabolites and find important metabolic pathways before and after treatment using Zhibai Dihuang Granule.Methods:We established a YDH model and a treatment model by intragastric administration of traditional Chinese medicine with hot nature and Zhibai Dihuang Granule.The rats of the control group were perfused by normal saline.Serum metabolites were detected by liquid chromatography-tandem mass spectrometry(LC-MS).Principal component analysis(PCA)and partial least squares-discriminate analysis(PLS-DA),coupled with univariate analyses such as the T test and fold change analysis,were adopted to screen differentially expressed metabolites based on KEGG and HMDB databases.Results:The average weight of the YDH model group significantly decreased compared with the control group,which represented that the rats of the model group were in a state of hyperfunction.Results of multivariate analyses indicated that three experimental groups were separated distinctly.According to multivariate analyses and univariate analyses coupled with KEGG and HMDB databases,the results were described as followed.Compared with the control group,38 metabolites were significantly increased and three metabolites were significantly decreased in the model group.Pathways involved included steroid hormone biosynthesis,tyrosine metabolism,lysine biosynthesis,arginine and proline metabolism,histidine metabolism,tryptophan metabolism,arachidonic acid metabolism and alpha-linolenic acid metabolism,which reflected the abnormality in the energy metabolism and immune function.After the treatment of Zhibai Dihuang Granule,12 metaboltes recovered obviously.Pathways involved included steroid hormone biosynthesis,histidine metabolism,arginine and proline metabolism and tyrosine metabolism,which suggested that Zhibai Dihuang Granule might treat YDH via regulating expression levels of these metabolites or pathways.Conclusion:Our study is the first to probe into the treatment mechanism of Zhibai Dihuang Granule on YDH and has discovered several differentially expressed metabolites and some important pathways related to YDH,which provides bases for other researches on YDH.