| Non-alcoholic fatty liver disease(NAFLD)is a very common but largely ignored global liver disease,with a high incidence and a trend of younger people.Moreover,NAFLD patients are often accompanied by abnormal metabolism of multiple organ tissues(such as liver,spleen and kidney).At present,there are some symptomatic drugs for lipid reduction and liver protection,but they are often accompanied by adverse effects.Phytoactive ingredients(such as flavonoids,phytomonoterpenes and phenolic acids)can effectively relieve weight gain and lipid metabolism disorders,and have a certain protective effect on the liver.Chlorogenic acid(CGA)is one of the most abundant and powerful phenolic acids in human diet,which can regulate liver metabolism.However,due to the complexity of "multi-target" NAFLD,the mechanism of CGA regulating the reduction of fat accumulation in NAFLD remains unclear,and the metabolic components of extrahepatic organs still need to be further explored.In this paper,non-targeted metabolomics,16 S r RNA gene sequencing and molecular docking techniques were used to analyze the protective mechanism of CGA against NAFLD from multiple perspectives The main findings are as follows:CGA supplementation decreased the elevated liver transaminase and lipid levels in NAFLD mice,improved lipid deposition in liver tissue,and reduced the levels of inflammatory factors.Metabolomics found that CGA mainly reversed phenylalanine,tyrosine and tryptophan biosynthesis,and also had a certain effect on primary bile acid biosynthesis in the liver.CGA significantly reversed purine,glycerophospholipid metabolism and other metabolic pathways in the spleen.CGA significantly affected histidine metabolism and sphingolipid metabolism,and also had regulatory effects on taurine and hypotaurine metabolism in the kidney.These results indicate that CGA can alleviate excessive lipid accumulation,reduce inflammatory response,regulate purine metabolism and triglyceride metabolism disorders,improve the metabolic disorders of liver,spleen and kidney,and thus play a protective role in liver injury induced by high fat diet.CGA supplementation improves colon tissue morphology,reduces FITC-Dex concentration and LPS levels,increases short-chain fatty acid(SCFAs)concentration,and protects intestinal barrier.CGA increased intestinal microbial richness;It upped the proportion of beneficial bacteria,including Lactobacillus and Bacteroides,and significantly lowered the relative abundance of microorganisms,such as Ruminnococcaceae and Desulfovibrio,11 kinds of microorganisms such as Muribaculaceae and Parasutterella were enriched.Correlation analysis showed that Ruminococcus was positively correlated with some lipid accumulation parameters,and negatively correlated with liver metabolites.Function prediction results showed that CGA intervention restored L-tryptophan biosynthesis and D-galacturonic acid degradation of intestinal flora,and down-regulated glycine betaine degradation and fatty acid reuse levels.It is suggested that CGA intake may alleviate hepatic steatosis by regulating intestinal microbiota composition and function and restoring intestinal barrier integrity.Cytochrome P450 enzyme cholesterol 7 alpha-hydroxylase(CYP7A1),Cytochrome P450 family 8 subfamily B member 1(CYP8B1)and Bile brine hydrolysase(BSH)were used to construct model target proteins,and CGA and its metabolites were used as ligands to screen out metabolites with high scores.Compared with positive control,CGA and its metabolites have high binding ability to target proteins,especially 3HA in CYP7A1.CYP7A1-3HA was simulated by molecular dynamics.RMSD,RMSF,Rg and SASA values determined by CYP7A1-3HA had a small fluctuation range,and there were continuous and stable hydrogen bond forces.These results indicate that CGA and its metabolites may enhance the enzyme activities of CYP7A1,CYP8B1 and BSH,increase the bile acid level,increase cholesterol consumption,reduce lipid accumulation in NAFLD,and improve the liver injury in NAFLD. |
