Study On The Mechanism Of Salidroside Intervening Furan Hepatotoxicity Based On Liver Metabolomics And Intestinal Flora

Furan is an endogenous pollutant commonly existing in heat-processed foods,and it has liver toxicity and potential carcinogenicity.Salidroside is a phenol glycoside compound widely existing in Rhodiola plants,and its pharmacological effects on anti-aging,anti-fatigue,liver and kidney protection have been confirmed.The purpose of this thesis is to explore the mechanism of furan on liver toxicity and the protective mechanism of salidroside from the two aspects of intestinal flora and metabolites by means of related molecular biology methods such as 16 S rDNA and LC-MS/MS.Firstly,the protective effect of salidroside on furan-induced liver injury was evaluated.Forty BALB/c mice were divided into 5 groups,which were the control group,furan-exposed group(8 mg/kg.bw/day),salidroside low-dose group(10mg/kg.bw/day),salidroside medium-dose group(20 mg/kg.bw/day)and salidroside high-dose group(40 mg/kg.bw/day)were administered lasting 30 days.The effects of salidroside on reducing the toxicity induced by furan were investigated through the changes of typical indicators and histopathology in mouse tissues.According to the experimental results,it was found that the levels of AST,ALT,and MDA in the furan-exposed group were significantly higher than those in the control group and the levels of GSH-Px,GST,and SOD decreased significantly.With the concentration of salidroside increasing,the levels of each index gradually recovered.Salidroside could reduce the significant increase of TNF-? and IL-6 content in serum induced by furan(p<0.05);while the content of IL-10 increased after giving different doses of salidroside,indicating that salidroside could regulate the body's immunity by inhibiting pro-inflammatory factors and increasing the secretion of inflammatory inhibitors.Secondly,the LC-MS/MS non-targeted metabolomics technology was used to determine the metabolites in liver tissues of mice.We found that furan could causemetabolic disturbances in the liver of mice,as shown by the screening of 38 biomarkers in the liver,and 23 biomarkers significant changes after salidroside administration.MetaboAnalyst 4.0 software was used to analyze the effect of furan on liver metabolic pathways.In positive ion mode,it mainly involved ?-linolenic acid metabolism,bile acid metabolism,galactose metabolism,taurine and subtaurine metabolism,arachidonic acid metabolism and so on;In negative ion mode,it mainly involved caffeine metabolism,bile acid metabolism,ketone body synthesis and degradation,biotin metabolism,sulfur metabolism,and so on.In view of the hepato-intestinal circulation of bile acid metabolism,RT-qPCR was used to verify the key target genes of the bile acid metabolism pathway.The results showed that salidroside could inhibit the expression of FXR and SHP in the liver and increase the content of CYP7A1 and BSEP,activate the gene expression of ileum FXR,SHP and FGF15,effectively regulate the bile acid signal pathway in the liver and ileum,and alleviate liver and intestine damage caused by the accumulation of bile acid.Thirdly,the effects of salidroside on intestinal flora diversity in a furan-induced liver injury mice model were studied by 16 S rDNA sequencing technology.Bacterial species structure had been greatly improved,the number of beneficial bacteria had been greatly increased,and the number of harmful bacteria had been relatively reduced after supplying salidroside.At the same time,significantly changed of BSH-containing bacteria such as Bacteroides,Bifidobacterium,and Clostridium with7? dehydroxylase activity were found,which was related to intestinal bile acid metabolism.Western blot technology was used to determine the expression of tight junction protein(ZO-1,occludin)in colon tissue and the ELISA method was used to determine the LPS content in serum,indicating that salidroside can change the diversity and abundance of intestinal flora effectively,alleviate the damage to the intestinal barrier and inhibit LPS levels in the serum,and then alleviate the intestinal dysfunction caused by furan..In summary,through the associated analysis of metabolomics and intestinal flora data,and the targeted study of the regulatory product-bile acid,and the application of RT-qPCR,Western blot and other technologies,the research concluded that salidroside can regulate liver metabolism,especially relieve the disturbance of the hepato-intestinal circulation of bile acid metabolism,thereby maintaining the intestinal flora balance and the integrity of the intestinal barrier,reducing the level of bacterial product LPS,and alleviating liver damage caused by furan in mice,whichprovides theoretical basis for salidroside development and application as a potential food-borne hazard inhibitor.