Analysis Of Hepatic CYP1A Enzymes In Rats With Progressive Stages Of Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a kind of chronic liver disease not due to excessive alcohol use, drug infection and autoimmune factors, including benign hepatic steatosis, its evolution of non-alcoholic steatohepatitis (NASH) and cirrhosis of liver, and eventually may lead to liver dysfunction. Liver fatty degeneration and lipid metabolism dysfunction will seriously affect the functions of the liver, and may cause a series of pathological syndrome. With the continuous improvement of people’s living standard, the incidence of NAFLD is increasing year by year, seriously affecting people’s quality of life.Cytochrome P450 enzymes (CYP450) is a class of mono-oxygenase system, existing mainly in the liver and gut. It can participate and catalytic variety of endogenous substances and xenobiotics metabolism, and is closely related to the pathogenesis of NAFLD. CYP450 enzymes mediated lipid oxidation and the generation of oxygen free radicals, resulting in hepatocytes steatosis, steatohepatitis, fibrosis and a serious of pathological changes. In the progressive stages of NAFLD, CYP450 enzymes system is affected by many factors, leading to the activity and protein expression changes. In previous studies, the activity and protein expression of CYP450 enzymes in different subtypes is often different, the alterations of the same subtype is often controversial. In this experiment, SD rat models NAFLD were successfully induced by high-fat emulsions, the activity and protein expression of CYP1A1 and CYP1A2 were detected by probe drug method and western blot analysis, which is closely related to the onset of NAFLD. And then, explore the mechanism between them, and provide theoretical basis for the clinical treatment. The main contents of this paper are as follows:1. Analysis of hepatic CYP1A1 enzyme in rats with progressive stages of NAFLD Objective:To explore the alterations of CYP1A1 activity and protein expression in rats liver with progressive stages of NAFLD. Methods:According to the characteristics of each NAFLD periods induced by high fat emulsion, a group of rats were killed at the 1, 9,13,17 week to do H&E staining, select the best representative of the diagnostic criteria of current rat models and merge them together. RP-HPLC was used to detect the metabolite resorufin and western blot was applied to detect the relative protein expression. Results:According to the concentration of resorufin, the metabolic activity of CYP1A1 were (0.307±0.016 μM) in normal group, (0.343±0.011 μM) in mild steatosis group, (0.395±0.034 μM) in serious steatosis group and (0.457±0.049 μM) in NASH group. While, to the result of western blot, the protein expression of CYP1A1 was increased during NAFLD progression. Conclusion:In the process of NAFLD in rats, both the activity and the protein expression of CYP1A1 increased.2. Analysis of hepatic CYP1A2 enzyme in rats with progressive stages of NAFLD Objective:To explore the alterations of CYP1A2 activity and protein expression in rats liver with progressive stages of NAFLD. Methods:High fat induced NAFLD rat models were prepared, RP-HPLC was used to detect the metabolite acetaminophen and western blot was applied to detect the relative protein expression. Results:According to the concentration of acetaminophen, the metabolic activity of CYP1A2 were (1.79±0.15 μM) in normal group, (2.43±0.18 μM) in mild steatosis group, (2.43±0.18 μM) in serious steatosis group and (1.42±0.09 μM) in NASH group. While, to the result of western blot, the protein expression of CYP1A1 was decreased during NAFLD progression. Conclusion:In the process of NAFLD in rats, elevated CYPl A2 activity at the initial period of NAFLD, but then decreased consecutively with increasing disease severity, while, the protein expression of CYP1A2 was decreased.