Protective Effect Of PDTC In A Rat Model Of Nonalcoholic Fatty Liver Disease And The Possible Mechnaisms

Objects:To establish a rat model of nonalcoholic fatty liver disease (NAFLD)with high-fat diet; To assess the effects of anti-NF-KB antibody pyrrolidine dithiocarbamate (PDTC) in experimental NAFLD model and to explore the mechanisms of PDTC in NAFLD.Methods:Fifty-two male SD rats were randomly divided into six groups after fed with normal diet for 7 days:(1), Simple Fatty Liver groups:control group(n=8), which were fed on normal diet; high-fat diet group(n=10), which were fed on high-fat diet; treated group(n=8), which were fed on high-fat diet. At the end of 8 week,2 rats were randomly drew off from each group to identify the Simple Fatty Liver model; rats of control group were given normal sodium chloride 0.3ml every day for 4 weeks, and rats of high-fat diet group were suspended feding on high-fat diet and were given normal sodium chloride 0.3ml every day for 4 weeks; For treated group, the rats were suspended feding on high-fat diet and were given PDTC 100mg/kg/day with intraperitoneal injection for 4 weeks; at the end of 12 week, all rats were killed; (2), Nonalcoholic steatohepatitis (NASH) groups:control group(n=8), which were fed on normal diet; and high-fat diet group(n=10), which were fed on high-fat diet; treated group(n=8), which were fed on high-fat diet. At the end of 12 week,2 rats were randomly drew off from each group to identify the Simple Fatty Liver model; rats of control group were given normal sodium chloride 0.3ml every day for 4 weeks, rats of high-fat diet group were suspended feding on high-fat diet and were given normal sodium chloride 0.3ml every day for 4weeks; For treated group, the rats were suspended feding on high-fat diet and were given PDTC 100mg/ kg/day with intraperitoneal injection for 4 weeks; at the end of 16week, all rats were killed; After executing, serum alanine aminotransferase (ALT),aspartate aminotransferase(AST),triglyceride(TG),total cholesterol (TC), high-density lipoprotein (HDL), fasting blood glucose(FBS) and fasting insμlin(Fins) were measured by drawing blood from the heart; then, the liver was dissociated and weighed, fasting insulin resistance index(FIRI) and lixer index were calculated;Hepatic pathological changes were assessed by using HE staining, Red oil staining and Masson staining, The expression of NF-κB p65 in liver tissue was detected by immunohistochemistry, The TNF-a mRNA, IL-6 mRNA and PPARa mRNA were measured by RT-PCR.Results:HE staining showed that the model of simple fatty liver and NASH were successfμlly established; Compared to the corresponding period of control groups, the liver index, levels of serum ALT, AST, TG, TC and FIRI of the high-fat diet groups of Simple Fatty Liver groups and NASH groups were higher, HDL were lower, there were statistics differences between them(p<0.05 or p<0.01); Compared to the corresponding period of high-fat diet groups, the liver index, levels of serum ALT, AST, TG, TC and FIRI of the treated group of Simple Fatty Liver groups and NASH groups were lower, HDL were higher, there were statistics differences between them(p<0.05 or p<0.01); HE staining, Red oil staining and Masson staining showed that the pathological changes were better than that of the high-fat diet groups; immunohistochemistry showed the expression of NF-κB p65 in the nucleus were lower than that of the high-fat diet groups, and there were statistics differences between them(p<0.05); RT-PCR showed the expression of TNF-a mRNA and IL-6 mRNA were lower than that of the high-fat diet groups, and there were statistics differences between them(p<0.05), the expression of PPARa mRNA were higher than that of the high-fat diet groups, and there were statistics differences between them(p<0.05); Between the high-fat diet groups, there were statistics differences for the liver index, levels of serum ALT, AST, TG, TC and FIRI, the degree of liver steatosis, inflammation, the area of lipid droplets and fibrous tissue area, NF-κB p65, TNF-a mRNA, IL-6 mRNA, PPARa mRNA; Between the treated groups(p<0.05), there were the same results(p<0.05).Conclusions:1. The SD rat model of Simple Fatty Liver can be successfμlly established by constantly feeding high-fat diet for 8 weeks.2. The SD rat model of NASH can be successfμlly established by constantly feeding high-fat diet for 12 weeks.3. PDTC can improve IR, the liver function and reduced the serum lipid, may play a therapeutic role in SD rat with NAFLD.4. PDTC have the effect of losing weight, adjusting lipid metabolism, anti-inflammatory, and can inhibit NF-κB into the nucleus, the mechanism may be relevent to the effect of inhititing NF-κB into the nucleus, then reducing expression of TNF-a mRNA, IL-6 mRNA and increasing the expression of PPARa mRNA in the liver.5. PDTC may become a new safe and effective drug for NAFLD.