Research Of Monascus Vinegar On Lipid Metabolism And The Mechanism In HFD-fed Rat

Monascus vinegar(MV)is a typical functional fermented food.MV is used as starter to produce variety of bioactive components such as organic acids,pigments,lovastatin,and polyphenols,therefore,MV considered as an effective functional food to regulate dyslipidemia because of its nutritional and medicinal value.At present,the research of single components or extract of MV on lipid metabolism are mainly concentrated.However,as a complex system of multi strain fermentation and containing a variety of active substances,the mechanism of MV in regulating lipid metabolism is unrevealed.Therefore,16 S r RNA was used to explore the effects of MV on intestinal flora structure and intestinal function,and the relationship between intestine and lipid metabolism was established.Therefore,the biological pathways of MV regulating lipid metabolism by using 16 S r RNA technology,serum metabolomics and liver transcriptomics.Taking human hepatoma cells(HepG2)as a model,a homeostasis model of MV regulating lipid metabolism was constructed to clarify the mechanism of the vinegar preventing lipid metabolism disorder.The results further strengthen the understanding of the function of MV,provide new strategies for dietary intervention to prevent metabolic diseases related to dyslipidemia,and provide new ideas and method guidance for the research of other food functional components to improve the body’s lipid metabolism.The study investigated the effect of MV on lipid metabolism in high-fat diet(HFD)rat,the results showed that 4 m L/kg body weight dose of MV regulated the increase of body and liver weights significantly.Compared with the Model group,the serum lipid synthase ACC decreased by 43.23%,the lipid decomposing enzymes ATGL and CPT-1 increased by31.83% and 41.69% respectively,and the content of FFA of TG decomposition decreased by 29.04%.Meantime,the levels of lipid synthase FAS,ACCA and lipolytic enzyme LPL in liver were significantly regulated by MV either,which regulated the levels of blood lipid and liver fat effectively.Based on the results of liver pathology,the liver injury caused by hepatic steatosis was reduced by MV while preventing liver lipid peroxidation.The effect of MV on intestinal homeostasis was studied by 16 S r RNA high-throughput sequencing.16 S r RNA analysis showed that MV targeted to reduce the abundance of Allobaculum,Bacteroides,Fusicatenibacter,Blautia and Agathobacter proinflammatory bacteria and increase the abundance of unclassified＿f＿Ruminococcaceae,Ruminococcaceae＿UCG-014,Lachnospiraceae＿NK4A136＿group and norank＿f＿Muribaculaceae regulating blood lipid and cholesterol bacteria to regulate the structure of flora.The levels of intestinal SCFAs were monitored by GC-MS,the results showed that the concentrations of acetic acid and propionic acid significantly in HD group,and increased the m RNA levels of claudin-1,ZO-1 and occludin by 26.79%,47.12% and47.81% respectively,as well as decreased the expression and phosphorylation levels of MAPK,NF and PI3 K by 31.98%,43.88% and 40.12%,so as to alleviate intestinal injury and enhance intestinal barrier function.Pearson analysis showed that unclassified＿f＿Ruminococcaceae,Ruminococcaceae＿UCG-014,Lachnospiraceae＿NK4A136＿group and norank＿f＿Muribaculaceae were the dominant bacterium of MV regulating intestinal function and was significantly correlated with lipid metabolism parameters.These results show that MV provides guarantee for maintaining intestinal function and flora structure and preventing harmful metabolites from entering the circulatory system.Serum metabolomics and multi sequence comparative analysis showed that lipid metabolism and digestive system were the main metabolic pathways regulated by MV.Based on the screening results of KEGG secondary pathway,glycerol phospholipid metabolism and arachidonic acid metabolism were the main lipid metabolism pathways and bile acid metabolism was the unique pathway regulated by MV.Multivariate statistics showed that lyso PC(20:0),lyso PC(24:0),lyso PC(24:1(15Z)),lyso PC(22:0),glycerphosphocholine,glycocholic acid,cholic acid,choline,2-phenylethanol glucuronide and deoxycholic acid were potential marker regulated by MV.The potential mechanism of MV in preventing lipid metabolism disorder was revealed from overall metabolism perspective.To clarify the molecular mechanism of MV regulating lipid metabolism,the liver gene spectrum was sequenced by transcriptome technology.It was obtained that lipid metabolism pathway,PPAR signal pathway and bile secretion pathway were the main metabolic pathways regulated by MV.The differential genes in glycerol phospholipid metabolism,arachidonic acid metabolism and fatty acid degradation pathway are mainly involved in the synthesis and oxidative decomposition of fatty acids,and are regulated by PPARα directly.Therefore,PPARα-Bile acid signaling pathway is speculated to be the main pathway for MV to regulate lipid metabolism.q RT-PCR and Western blot confirmed that MV played a role in regulating lipid metabolism by increasing the expression of lipid decomposition genes Acat2,Cpt1 a and Acaa1 b or proteins CPT-1 and ATGL,and reducing the expression of lipid synthesis gene Cyp4a3 or proteins ACCα and FAS.The decreased expression of cholesterol synthesis protein HMGCR significantly enhanced the expression of cholesterol transporter Apo A1,increased the expression of LDLR and CYP7A1 in bile secretion pathway and promoted bile acid transformation.It was confirmed that PPARα-Bile acid signaling pathway is the molecular mechanism of MV regulating lipid metabolism disorder.HepG2 cell model combined with PPARα Gene Silencing experiment confirmed that the expression of PPARα was regulated by 3 μL/m L MV,the expression of lipid synthesis protein SREBP-1,FAS and ACCα was inhibited and the expression of the lipid decomposition protein CPT-1 and ATGL were promoted.Meantime,compared with oleic acid(OA)group,the decreased expression of cholesterol synthesis protein SREBP-2significantly increased the expression of bile transformation protein LXR and CYP7A1 in bile secretion pathway,which can improve bile secretion and promote lipid mitochondrial oxidation.The model of MV regulating lipid metabolism homeostasis in HepG2 cells was successfully constructed.And clarified that the PPARα-Bile acid signaling pathway is the core mechanism of MV regulating lipid metabolism disorder.