Study Of Orlistat On Anti-steatosis In Rat Models Of Non-alcoholic Fatty Liver Disease

Background:Nonalcoholic Fatty Liver Disease?NAFLD?is the leading cause of chronic liver disease in developed countries.And with the continuous improvement of people's living standards,the number of NAFLD patients around the world is also increasing.NAFLD may develop into its associated hepatitis,cirrhosis,and even liver cancer.Therefore,it is crucial to actively seek therapeutic targets of NAFLD and effective therapeutic drugs against NAFLD.Orlistat,whose efficacy in weight loss is proven,is the only over-the-counter weight loss drug in the current world,but its role in the hepatopathy of NAFLD remains to be determined.Objective:To investigate the effect of orlistat on hepatic steatosis in rats with NAFLD and its possible mechanism.Methods:1.The model:after one week of adaptive feeding of the purchased SPF-rated healthy male SD?Sprague-Dawley?rats,dividing these rats into two groups,the blank control group and the model group,by adapting the method of random number table;the former was fed normal diet while the latter was fed high-fat diet,and after 10 weeks,three rats were choosed in each group randomly for Hematoxylin-eosin staining?HE?in the liver;when the microscope showed that more than5%of liver cells are in vacuolar degeneration,it suggested the model was successful.2.Drug intervention:after the success of the model,the model group was randomly divided into 5 groups,respectively,vitamin E group?VE?,blank model group,high dose orlistat group,middle dose orlistat group,and low dose orlistat group,and there were 8 rats in each group;while feeding the high-fat diet,each group was given corresponding drug gavage separately(the VE group was given 200 mg·kg^-1d^-1 vitamin E gavage,the blank model group was given 2 ml·d^-1 normal saline gavage,and the high,middle,low orlistat groups were respectively given 15,10,5 mg·kg^-1·d^-1 orlistat gavage);the blank control group was fed with ordinary diet and given 2ml·d-1 normal saline gavage.3.Data collection:weighing these rats weekly and after 8 weeks drug intervention,measuring the weight and the body length of the rats,after that,killing them,and then separating and weighing their own liver,epididymal fat and perirenal fat;ALT?TG?TC and blood glucose were detected in the blood samples;adding HE staining in pathological sections of the liver to observe the degree of hepatic steatosis;the expression level of malondialdehyde?MDA?was detected by immunohistochemistry and the protein expression changes of leptin and retinol binding protein 4?RBP4?in liver tissue was detected by Western blot.Results:1.At the 11th week,every group selects three rats randomly.If HE staining of liver pathological sections in the model group showed that the vacuolar degeneration of liver cells was more than 5%,while the blank control group revealed no significant hepatic fatty degeneration of liver cells,it would indicate that the modeling was successful.2.After 8weeks of different drug interventions,compared with the blank control group,general indicators such as weight,wet liver weight,epididymal fat and perirenal fat,and serum biochemical indicators like ALT,TG,TC and blood glucose in rats increased to different degrees?P<0.05?.In addition,compared with the blank model group,the general indicators and the serum biochemical indexes in the drug intervention groups show decreased?P<0.05?.3.In the blank control group,no significant vacuolar degeneration was visual in HE staining of liver sections;in drug intervention groups and blank model group,varying degrees of vacuolar degeneration were observed;in the drug intervention groups,different degrees of vacuolar degeneration were decreased,in a dose-dependent manner.4.Immunohistochemical results showed that MDA expression increased in the drug intervention groups and blank model group,while compared with blank model group,it showed decreased in the drug intervention groups?P<0.05?,especially in the high dose orlistat group?P<0.05?.5.WB results indicated that the protein expression levels of leptin and RBP4 showed decreased in the drug intervention groups?P<0.05?,especially in the high dose orlistat group?P<0.05?.Conclusions:?1?Rats feed a high-fat diet for 10 weeks are able to make the liver meet the requirements of NAFLD model.?2?Orlistat can reduce body mass index,liver index and visceral fat proportion,blood lipid,ALT and blood glucose in NAFLD model rats;?3?Orlistat may fight hepatic steatosis by down-regulating MDA,leptin and RBP4.