Ameliorative Effect Of Sipunculus Nudus L.Polysaccharide On Non-alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease(NAFLD)is prevalent in many areas.It has a prominent feature is the accumulation of fat in liver cells.The cause of the disease is complex,but not including alcohol and other factors that can cause clear liver damage.NAFLD is not only a chronic liver disease,but also with the deepening of the pathological changes,it may develop from simple fatty liver to hepatitis.Severe cases it can develop into liver cancer.According to statistics,the incidence of NAFLD in western countries is about 20-30%.And the incidence of NAFLD in China is about 15%.The prevalence of NAFLD was increased with the increase of obesity and other metabolic syndrome.It has developed into second chronic liver diseases in China.NAFLD has become one of the most serious diseases that seriously damage the national physical and mental health and affect the social stability and harmony.The polysaccharide of Sipunculus nudus L.(SNPS)is a kind of important bioactive components isolated from Sipunculus nudus L.It has multiple physiological functions,such as enhancing immunity,anti-oxidation,anti-aging.At present,the domestic and foreign research on SNPS biological activity has achieved certain results,but the research of the polysaccharide on the prevention and treatment of nonalcoholic fatty liver and its mechanism of action is less.Therefore,this subject use SNPS as raw material.Optimization of the extraction process of polysaccharide by ultrasonic assisted.The polysaccharide purification use DEAE-52 and Sephadex G-100,and exploring its structure by infrared spectroscopy(IR)and gas chromatography(GC).To use of high fat animal model,we explore the therapeutical effect of SNPS to NAFLD.By using the steatosis cell model,we evaluate the effect of purified polysaccharides to NAFLD.Through the determination of some physiological and biochemical indexes and related protein expression,we explore the possible mechanism of SNP from lipid accumulation and oxidative stress.The main results are as follows:1.Through the single factor experiment and response surface,the sequence of various factors effect polysaccharide extraction yield is ultrasonic temperature,ultrasonic power,ultrasonic time,material liquid ratio.The optimum extraction conditions of polysaccharide in ultrasonic assisted:liquid ratio 1:25(g:mL),ultrasonic temperature is 70?,ultrasonic time 48min,ultrasonic power is 387W.Under this process we performed 5 validation tests,the average yield of SNP is 7.0295%.2.SNP purification use DEAE-52 and Sephadex G-100.Three purified polysaccharides were obtained,named SNP1,SNP2,SNP3.The structure and monosaccharide composition were determined by IR and GC.3.To use of high fat animal model,we explore the therapeutical effect of SNPS to NAFLD.The results shows:after 8 weeks of high-fat diet fed,the body weight,liver weight,liver coefficient of golden hamster was significantly higher than the normal diet of golden hamsters.PD group and SNPS group weight and liver index were significantly decreased than the model group(P<0.05 or P<0.01).The PD and SNPS can significantly reduce weight and liver index of fat golden hamster.And they can effectively reduce the accumulation of fat in the liver,reducing the probability of inflammation in the liver.It can be seen from the blood lipid,compared with the normal group,the triglyceride and cholesterol levels in the model group were significantly higher.It can be concluded that the liver lipid metabolism disorders,modeling good results.PD group and SNPS group content of triglyceride and cholesterol were significantly lower than the model group(P<0.05 or P<0.01).Therefore,PD and SNPS have a certain regulatory effect on NAFLD induced by high fat diet.However,there was no significant difference between the high density lipoprotein and low density lipoprotein in each group.The ALT and AST values in the model group were higher than those in the normal group,and the difference was significant.PD group and SNP group were significantly lower than the model group.From some antioxidant indexes of hamster liver can be seen,the content of MDA of SNPS group and PD group was significantly lower than the model group.And their SOD activity was significantly higher than the model group.This suggest that SNPS can improve the total antioxidant capacity of golden hamsters.Thus,SNPS can reduce the accumulation of lipid of high fat diet hamster,and repair the hepatic injury.4.By using the steatosis cell model,we evaluate the effect of SNP,SNP1,SNP2,SNP3 to NAFLD.The results show:compared with the model group,SNP,SNP1,SNP2,SNP3 can significantly reduce the intracellular triglyceride content,and they also can reduce the activity of ALT and AST.Using Western-blot,we explore the mechanism that polysaccharides can improve NAFLD.The results showed that they could up regulate the expression of p-AMPK,PPAR?,ACOX1,and down regulate the expression of SREBP-1 protein.It can be concluded that drugs can regulate lipid metabolism through two aspects:lipid cumulation and oxidative stress by AMPK and PPARa pathway.