| Objective With the change of living and producing style, the incidencesof non-alcoholic fat liver disease (NAFLD) have been rising. At present, thereare two ways to regulate lipid: non-drug therapy and drug therapy. The formerincludes changing the lifestyle (lowing calorie diet, exercise, losing weight,educing the waistline). The latter includes improving IR and correctingmetabolic disorder, such as Insulin sensitization and statins. NAFLD is closelyrelated to the unreasonable diet structure and unbalanced nutrient. Only relingon drug treatment, the effect is not ideal. Understanding hepatic fibrogenesisin NAFLD is an important research area and will be valuable for identifyingpotential therapeutic targets to prevent the progression of fibroticsteatohepatitis to more severe disease. So far, dietary intervention is worthin-depth and widely explored.Intermittent fasting (IF) is a new form of diet plan, usually adopting themethod of alternate-day fasting (ADF), namely the first day fasting and takingfood on the following day. Foreign research datas show that ADF can reducerats fasting plasma glucose, improve insulin sensitivity, lower heart rate andblood pressure, reduce the concentration of cholesterol and triglyceride, andincrease the concentration of high-density lipoprotein. However, molecularmechanisms of these effects are yet to be fully defined, needing furtherresearch. Calorie restriction (CR) that is another kind of diet intervention hasthe same effect with ADF. At present, there is a lot of relevant researchdocumentation at home and abroad. Since proposed the theory that the CR hasanti-aging proposed, the biological effect of CR aroused people’s more andmore attention. Studies have shown that CR can lighten the weight, lowerblood pressure, reduce rats fasting plasma glucose, improve insulin sensitivity,lower cholesterol levels, and made older animal keep physiological state when they are young, such as the sensitivity of the response to external stimuli. Theaim of this study is to elucidate the effect of ADF on liver function and serumlipid levels in rat with non-alcoholic fatty liver disease induced by high-fatdiet. Provide new strategies and experimental basis for clinical effectiveprevention and treatment of nonalcoholic fatty liver disease.Methods Fifty male wistar rats were randomly divided into2groups:Blank group (n=12, fed with normal food) and NAFLD model group (n=38,fed with high-fat food). Eight weeks later2rats were randomly selected fromeach group and were killed to undergo pathological examination of the liver.When the experimental model of NAFLD rats was established, the remainingNAFLD rats were divided into4groups randomly:(1) Control group fed withnormal diet,(2) ADF group fed in the form of ADF,(3) CR group fed withnormal diet which were60%of control group,(4) NAFLD group fedcontinuously with high-fat diet. The body-weight and diet consumption wererecorded during the experiment of4week. After fasting and water deprivationfor more than12hours, all of the animals were anesthetized and weighted.Blood samples were collected from heart for biochemical analysis. Liverswere weighted and partly fixed in10%formalin for histological analysis.Liver injury was estimated by serum ALT, AST and ALP levels andhistological examination. The TC, TG, HDL-C, LDL-C, VLDL-C levels,weight, liver index also were analyzed.Results1The rat of NAFLD group showed less activity than the Control group,sikness and dim hair. The rat of ADF group and CR group showed moreactivity, shiny hair and good appetite. ADF and CR group rats improvedsignificantly on the general condition than NAFLD group.2Liver tissue pathology observation: The high-fat diet resulted insteatosis, inflammatory in rat liver section. The rat of NAFLD group showedthe histologic appearance of hepatic fatty change. Compared with NAFLDgroup, the hepatic lobules injury of treatment groups were decreased. The livertissue of ADF group was improved as similarly as the CR group. 3The determination of weight and liver index in rats: The weight andliver index were increased by high-fat diet (P＜0.05) compared to the Blankgroup. The weight and liver index of ADF group were decreased significantly（P＜0.05）compared to the NAFLD group. And the CR group weredecreased significantly （P＜0.05). The Control group were decreasedsignificantly (P＜0.05). The weight of ADF group were decreasedsignificantly（P＜0.05）compared to the CR group, nevertheless, there was nostatistically significant difference in the liver index.4The level of serum liver function test in rats: The serum alanineaminotransferase (ALT), aspartate aminotransferase (AST) and alkalinephosphatase (ALP) levels of NAFLD group were increased significantly (P＜0.05) compared to the Blank group. The serum AST, AST and ALP of ADFgroup were decreased significantly (P＜0.05) compared to the NAFLD group.The serum AST, AST and ALP of CR group were decreased significantly (P＜0.05）compared to the NAFLD group. The serum ALT and ALP of the controlgroup were decreased significantly (P＜0.05) compared to the NAFLD group,nevertheless, there was no statistically significant difference in the serum AST.The serum ALT of ADF group were decreased significantly (P＜0.05)compared to the CR group, nevertheless, there was no statistically significantdifference in the serum AST and ALT.5The level of serum lipid test in rats: The serum total cholesterol (TC),triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and very lowdensity lipoprotein cholesterol (VLDL-C) levels of NAFLD group wereincreased significantly (P＜0.05) compared to the Blank group, and the highdensity lipoprotein cholesterol (HDL-C) were decreased significantly (P＜0.05). The serum TC, TG, LDL-C and VLDL-C levels of ADF group weredecreased significantly (P＜0.05) compared to the NAFLD group, and theHDL-C were increased significantly (P＜0.05). The serum LDL-C andVLDL-C levels of ADF group were decreased significantly (P＜0.05)compared to the CR group, nevertheless, there was no statistically significantdifference in the serum TC, TG and HDL-C. The serum TC, TG, LDL-C and VLDL-C levels of CR group were decreased significantly (P＜0.05)compared to the NAFLD group, and the HDL-C were increased significantly(P＜0.05). The serum TC, TG, LDL-C and VLDL-C levels of ADF groupwere decreased significantly (P＜0.05) compared to the control group, and theHDL-C were increased significantly (P＜0.05).Conclusion1High fat diet can successfully establish the experimental model ofNAFLD.2Alternate day fasting have the effects of lowering significantly lowerthe serum lipids level and protecting the liver function, and then improvenon-alcoholic fatty liver disease. Its mechanism may be alternate-day fastingby increasing insulin sensitivity and regulating lipid metabolism disorder playthe role of lowering lipid and protecting liver.3The prevention effects of alternate-day fasting on non-alcoholic fattyliver disease are similar to those of calorie restriction, but in terms of lipidmetabolic abnormalities may be superior to caloric restriction.4Compared to normal diet, non-alcoholic fatty liver disease treated byalternate day fasting bring better results. |
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