| Objectives:An experimental rat model of NASH was established by feeding SD rats a high-fat diet and intervened with TSRC by gavage. By detecting the MDA content, the T-AOC activity in the serum of the inferior vena cava and the content of MDA, the activity of GSH-Px, CAT, SOD in the supernatants of liver tissue among the experimental NASH rat model group, the TSRC group, the polyene phosphatidylcholine group and the blank group, and analyzing the differences in the oxidative capacity and the antioxidant capacity respectively in each group, we aimed to observe and discuss the curative effect that TSRC intervened the oxidative stress existed in an experimental rat model of NASH and the mechanism in the process.Methods:1 The modeling method:14 rats were selected randomly from 50 clean healthy male SD rats and assigned to the blank group, then the remaining 36 rats were assigned to the modeling group. The blank group and the modeling group were fed with a normal diet and a high-fat diet (ingredients:82.5% normal diet+10% lard+5% yolk powder +2% cholesterol+0.5% sodium cholate) respectively for 16 weeks. We selected 1 rat from each group at the end of the 4th week,1 rat from each group at the end of the 8th week,2 rats from each group at the end of the 12th week,2 rats from each group at the end of the 16th week randomly and measured their body weight, wet liver weight and liver index. We collected the blood from the inferior vena cava to detect AST, ALT, TC, TG levels and took the moderate liver tissue from the centre of the right hepatic lobe to observe the steatosis, inflammation and fibrosis of hepatic tissues by HE staining with the light microscope. Finally, according to the results of the detection and the observation to estimate whether the experimental rat model of NASH had been established successfully.2 The intervening method:Following the successful establishment of the experimental rat model of NASH, the remaining 30 rats of the modeling group were randomly divided into the model group, the polyene phosphatidylcholine group and the TSRC group, with 10 rats in each group and were still fed with a high-fat diet. The remaining 8 rats of the original blank group were assigned to the blank group and were still fed with a normal diet. Four groups had been respectively intervened with 0.9%NS, polyene phosphatidyl choline [195.4 mg/(kg.d)], TSRC [50mg/(kg.d)], and 0.9%NS by gavage for 8 weeks, and the dose was 3ml/d. Meanwhile, the general conditions of rats in all groups were observed carefully.8 weeks later, we collected the blood from the inferior vena cava to detect the serum MDA content, the serum T-AOC activity and took the supernatants of liver tissue to detect the content of MDA, the activity of GSH-Px, CAT, SOD in four groups and analyzed the differepces in the oxidative capacity and the antioxidant capacity respectively in each group.Results:1 Results of the modeling:1.1 General conditions of rats:Gradually, the rats in the modeling group had bad furs, reduced their activity amount, lost appetite, increased water intake, had soft and thin stools and so on. While the rats in the blank group had smooth and tidy furs, acted actively, had the normal appetite, water intake, stools and so on.1.2 Body weight, wet liver weight and liver index of rats:The body weight of the modeling group and the blank group both increased gradually, but there was no statistic significance (P=0.351). The wet liver weight of the modeling group and the blank group both increased gradually, and there was a statistic significance(P=0.011). The liver index of the modeling group increased gradually, while that of the blank group didn’t, and there was a notable statistic significance (P=0.000)1.3 Transaminases and lipid indexes of rats:The AST, ALT, TG levels of the modeling group increased gradually, while the TC level remained stable from the end of the 4th week, and the AST, ALT, TG, TC levels of the blank group didn’t increase obviously. The AST, ALT, TG, TC levels of the modeling group were evidently higher than those of the blank group, and there were statistic significances respectively (P=0.000, P=0.002, P=0.000, P=0.023)1.4 Observation of the rats livers:Macroscopic observation:The livers of the modeling group had the surfacess of bad gloss and light yellow color, the increased liver volume, the slightly blunt edge and a greasy cross section, while the livers of the blank group had the smooth surfaces of soft texture and pink color, the moderate volume and the sharp edge. Macroscopic observation:The hepatic histology of the modeling group showed a typical rule of normal-NAFL-NASH pathological change, but it didn’t show fibrosis. At the end of the 16th week, the hepatic steatosis degree of modeling group was IV (F4), the hepatic inflammation grade was 2 (G2),the hepatic fibrosis stage was 0 (SO), NAS was 8 scores and those of the blank group were F0G0S0, NAS 0 score. There were statistic significances respectively in the differences of the hepatic steatosis degree, the hepatic inflammation grade and NAS between the modeling group and the blank group (P=0.005, P=0.021, P=0.000)1.5 The comprehensive evaluation:By feeding SD rats with a high-fat die (ingredients: 82.5% normal diet+10% lard +5% yolk powder +2% cholesterol+0.5% sodium cholate) for 16 weeks, we successfully established an experimental rat model of NASH(F4G2S0, NAS 8 scores), accompanied by overweight, an evidently increased liver index, hyperlipidemia and abnormal aminotransferases.2 Results of the intervention:2.1 General conditions of rats:Compared with the model group, the phenomena that poor furs, reduced activity amount and bad appetite of polyene phosphatidyl choline group and TSRC group were improved after gavage intervention. The rats of the model group, the polyene phosphatidyl choline group and the TSRC group still drank a lot, and the stools of them were still soft and thin, especially in the TSRC group. The rats in the blank group had smooth and tidy furs, acted actively, had the normal appetite, water intake, stools and so on. The increase of weight of all the rats was slow relatively.2.2 The serum MDA contents and the hepatic MDA contents of rats:Compared the blank group with the model group, the serum MDA contents and the hepatic MDA contents of the model group were higher than the blank group’s, and there were notable statistic significances respectively(P<0.01). Compared the TSRC group with the model group, the serum MDA contents and the hepatic MDA contents of the TSRC group were lower than the the model group’s, and there were statistic significances respectively (P<0.05). Compared the polyene phosphatidyl choline group and the model group, the serum MDA contents and the hepatic MDA contents of the polyene phosphatidyl choline group were lower than the the model group’s, and there were statistic significances respectively (P<0.05). The serum MDA contents and the hepatic MDA contents of the blank group, the TSRC group and the polyene phosphatidyl choline group were equivalent, and there were no statistic significances respectively (P>0.05)2.3 The serum T-AOC activity and the hepatic GSH-Px, CAT, SOD activity of rats: Compared the blank group with the model group, the serum T-AOC activity and the hepatic GSH-Px, CAT, SOD activity of the model group were lower than the blank group’s, and there were notable statistic significances respectively (P<0.01) Compared the TSRC group with the model group, the serum T-AOC activity and the hepatic GSH-Px, CAT, SOD activity of the TSRC group were higher than the the model group’s, and there were statistic significances respectively (P< 0.05) Compared the polyene phosphatidyl choline group and the model group, the serum T-AOC activity and the hepatic GSH-Px, CAT, SOD activity of the polyene phosphatidyl choline group were higher than the the model group’s, and there were statistic significances respectively (P<0.05). The serum T-AOC activity and the hepatic GSH-Px, CAT, SOD activity of the blank group, the TSRC group and the polyene phosphatidyl choline group were equivalent, and there were no statistic significances respectively (P>0.05)Conclusions:1. Feeding SD rats with a high-fat die (ingredients:82.5% normal diet+10% lard+5% yolk powder+2% cholesterol+0.5% sodium cholate) for 16 weeks can successfully establish an experimental rat model of NASH, but accompanied by no fibrosis.2. Oxidative stress exists in an experimental rat model of NASH.3. The TSRC and polyene phosphatidyl choline can both effectively improve the serum T-AOC activity and the hepatic GSH-Px, CAT, SOD activity and decrease the MDA contents in the experimental rat model of NASH to improve the oxidative stress condition, and their currative effects are equivalent.4. The therapy of TSRC by gavage may have an adverse reaction of diarrhea. |
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