Mitigative Effects And Mechanisms Of Seabuckthorn Polysaccharide And Lactobacillus Casei Zhang On Non-alcoholic Fatty Liver Disease Induced By High-fat Diet In Rats

Non-alcoholic fatty liver disease(NAFLD)is a common chronic liver disease,and the pathogenesis of NAFLD is complex.The pathogenesis of NAFLD has become a research hotspot.Studies have shown that seabuckthorn polysaccharide(SP)and probiotic Lactobacillus casei Zhang(Lcz)posess hepatoprotective effects.In this paper,we studied the mitigative effects and mechanisms of SP and probiotic Lcz on NAFLD through establishing experiment model of fatty liver disease induced by high-fat diet in rats.Male Wistar rats(6-8 weeks old)were randomly divided into 6 groups(n=8),Control group(Ctrl),HFD model group(HFD),Berberine positive medicine control group(HFD+BR),SP treatment group(HFD+SP),Lcz treatment group(HFD+Lcz)and SP and Lcz combined treatment group(HFD+SP+Lcz).After adaption for two weeks,rats in the Ctrl group were fed with standard diet(11.4% fat),while the other groups were continuously fed with a high fat diet(33.1% fat)for 6 weeks.After then,the HFD+BR group,HFD+SP group,HFD+Lcz group,HFD+SP+Lcz group were orally administrated with 50mg/kg BR,200mg/kg SP,1×109CFU/ml Lcz and 200mg/kg SP add 1×109CFU/ml Lcz solution,respectively.The high-fat diet was replaced by standard diet at the treatment period.Rats were sacrificed four weeks later.Serum,liver and feces samples were collected for subsequent analysis.The results showed that SP and Lcz decreased ALT and AST levels,MDA and NO levels both singly and in combination.HE staining result indicated a significant decrease in the degree of steatosis in SP and Lcz treatment groups.SP and Lcz inhibited the serum and hepatic expression o f IL-6,TNF-? and IL-1?,decreased the expression of TLR4,NLRP3 and AS C.In addition,SP and Lcz reduced the phosphorylation of MAPKs.The 16 S functional gene sequencing results indicated that,SP and Lcz treatment groups increased the relative abundances of Clostridia,Firmicutes and Ruminococcaceae at the levels of phylum,class,order,family,genus and species,while the relative abundance of Bacteroidaceae and Prevotellaceae was decreased.These results demonstrated that SP and Lcz alleviate the progression of NAFLD through regulation on inflammation,oxidation,lipid metabolism and the structure of the microbiota.