非酒精性脂肪性肝炎大鼠模型中小檗碱抗氧化效应的观察

Antioxidant effect of berberine in a rat model of nonalcoholic steatohepatitis

目的利用大鼠NASH模型及H2O2诱导氧化应激体外模型观察小檗碱的抗氧化效果。方法建立高脂饮食诱导大鼠NASH模型,给予小檗碱18 mg·kg-1·d-1灌胃治疗3周后,HE染色观察肝组织病理学改变,测定肝组织超氧化物歧化酶(GSH)、还原型合胱甘肽(SOD)活性和丙二醛(MDA)水平。建立H2O2诱导活性氧自由基(ROS)产生的氧化应激体外模型,流式细胞技术观察细胞内ROS水平,检测肝细胞内SOD、GSH、LDH和CAT的活性。计量资料多组间比较采用单因素方差分析,进一步两两比较采用Bonferroni检验;2组间比较采用t检验。结果经小檗碱治疗后,NASH大鼠肝组织炎性细胞浸润范围、灶状坏死和肝细胞气球样变可得到明显改善。同时肝组织GSH和SOD活性治疗组较模型组明显升高[(29.8±2.4)U/mg vs(19.9±1.3)U/mg,(26.6±1.9)μg/mg vs(19.7±1.4)μg/mg,P值均<0.001],MDA水平治疗组较模型组明显降低[(19.8±1.5)nmol/mg vs(24.0±2.0)nmol/mg,P<0.001]。在H2O2诱导氧化应激的体外模型中,发现H2O2组细胞内的ROS水平较小檗碱+H2O2组明显升高[(69.8±1.9)%vs(50.4±6.5)%,t=24.42,P=0.008]。同时小檗碱+H2O2组肝细胞内SOD和GSH的活性较H2O2组明显增加[(25.5±1.3)μg/mg vs(18.8±1.0)μg/mg,(27.1±0.6)U/mg vs(16.79±3.8)U/mg,P值均<0.001),LDH水平在小檗碱+H2O2组和H2O2组间变化不明显(P=0.103),而CAT的活性在各组间的变化差异无统计学意义(F=3.76,P=0.060)。结论从体内和体外模型同时证明小檗碱有明显的抗氧化作用,其作用机制可能与其增加抗氧化酶的活性有关。

Objective To investigate the antioxidant effect of berberine in a rat model of nonalcoholic steatohepatitis（NASH） and an in vitro model of oxidative stress induced by H2 O2. Methods High-fat diet was used to establish a rat model of NASH. After three weeks of treatment with berberine 18 mg/kg/d by gavage,HE staining was used to observe liver pathological changes,and the activities of glutathione（GSH） and superoxide dismutase（SOD） and the level of malondialdehyde（MDA） in liver tissue were measured. An in vitro model of oxidative stress induced by reactive oxygen species（ROS） due to H2 O2 was established; flow cytometry was used to measure the level of ROS,and the activities of SOD,GSH,lactate dehydrogenase（LDH）,and chloramphenicol acetyltransferase（CAT） in hepatocytes were measured. A one-way analysis of variance was used for comparison of continuous data between groups,and the Bonferroni test was used for further comparison between two groups; the t-test was used for comparison of continuous data between two groups. Results NASH rats had significant improvements in the extent of infiltration of inflammatory cells,focal necrosis,and ballooning degeneration of hepatocytes after berberine treatment. Compared with the NASH model group,the berberine group had significant increases in the activities of GSH（29. 8 ±2. 4 U/mg vs 19. 9 ± 1. 3 U/mg,P 0. 001） and SOD（26. 6 ± 1. 9 μg/mg vs 19. 7 ± 1. 4 μg/mg,P 0. 001） and a significant reduction in the level of MDA（19. 8 ± 1. 5 nmol/mg vs 24. 0 ± 2. 0 nmol/mg,P 0. 001）. In the in vitro model of oxidative stress induced by H2 O2,the H2 O2 group had a significant increase in the level of ROS compared with the berberine ＋ H2 O2 group（69. 8% ± 1. 9% vs 50. 4% ±6. 5%,t = 24. 42,P = 0. 008）. Compared with the H2 O2 group,the berberine ＋ H2 O2 group had significant increases in the activities of SOD（25. 5 ± 1. 3 μg/mg vs 18. 8 ± 1. 0 μg/mg,P 0. 001） and GSH（27. 1 ± 0. 6 U/mg vs 16. 79 ± 3. 8 U/mg,P 0. 001） in hepatocytes; there was no significant difference in the level of LDH between the berberine ＋ H2 O2 group and the H2 O2 group（P = 0. 103）,and there was no significant difference in the activity of CAT across all groups（F = 3. 76,P = 0. 060）. Conclusion Both in vivo and in vitro models show that berberine has a good antioxidant effect,possibly by increasing the activities of antioxidant enzymes.