小檗碱对非酒精性脂肪肝大鼠疗效及其机制的探讨

目的观察小檗碱对高脂饮食诱导的非酒精性脂肪肝大鼠治疗效果并探讨其可能的机制。方法将26只Sprague-Dawley大鼠(120~160 g)随机分为3组,分别为对照组(n=8)、模型组(n=10)和治疗组(n=8)。对照组大鼠给予普通饲料喂养,模型组及治疗组给予高脂饮食饲养。第12周,处死模型组2只大鼠,确认造模成功。随后治疗组大鼠给予150 mg·kg-1·d-1小檗碱灌胃4周,对照组及模型组给予相同剂量等渗盐水灌胃。第16周处死大鼠。HE染色观察大鼠小肠黏膜上皮绒毛变化;苏丹黑B染色观察肝脏脂肪变情况;免疫组织化学染色观察小肠上皮occludin蛋白表达;16S rDNA实时荧光定量PCR法测量大鼠粪便中大肠杆菌、拟杆菌及普拉梭菌的数量。结果模型组大鼠血清内毒素(0.288±0.045)和肿瘤坏死因子(TNF)-α(1.07±0.11)水平均高于对照组(0.192±0.049,0.94±0.07)(P<0.05),小檗碱干预可显著降低内毒素(0.213±0.025)和TNF-α水平(0.93±0.07)(P<0.05)。模型组大鼠肠黏膜上皮occludin蛋白表达(0.05±0.012)明显低于对照组(0.166±0.014),小檗碱对肠黏膜occludin蛋白表达有促进作用(0.055±0.009),但差异无统计学意义(P>0.05)。同时,与模型组(7.29±0.47)相比,对照组(9.49±0.59)拟杆菌数量降低,治疗组拟杆菌的数量增加(9.77±0.87);与对照组(5.42±0.63,9.49±0.59)相比,模型组大肠杆菌(6.92±0.77)、普拉梭菌(8.70±0.62)数量增加,小檗碱干预减少了大肠杆菌(6.34±0.71)、普拉梭菌(9.77±0.87)的数量(P<0.05)。结论小檗碱有效地保护了非酒精性脂肪肝大鼠的肠屏障功能,其作用机制可能是对肠道菌群的调节。

Discussion on the curative effect and mechanisms of berberine in rats with non-alcoholic fatty liver

Objective To observe the curative effects of berberine in rats with high-fat diet induced non-alcoholic fatty liver and to further explore its possible mechanism.Methods Twenty-six Sprague-Dawley rats(120-160 g)were randomly divided into 3 groups:control group(n=8),model group(n=10)and treatment group(n=8).Rats in the control group were fed with regular diet,and the model group and the treatment group were fed a high-fat diet.At the 12th week,two rats in the in the model group were sacrificed to verify whether model was successful established.Subsequently,treatment group rats were given a gavage of berberine at a dose of 150 mg·kg-1·d-1 for 4 weeks,and the control and the model group rats were given the same dose of normal saline.Rats were sacrificed at week 16th.HE staining was used to observe the changes in the intestinal mucosa of rats.Sudan black B staining was used to observe the fatty changes in liver.Immunohistochemical staining was used to observe the expression level of occludin protein in the intestinal epithelium.A real-time 16S rDNA PCR method was used to measure the number of escherichia coli,bacteroides and faecalibacterium prausnitzii in the feces of rats.Results Model group had a higher serum levels of endotoxin(0.288±0.045)and tumor necrosis factor(TNF)-α(1.07±0.11)than the control group(0.192±0.049,0.94±0.07)(P<0.05).Berberine intervention had significantly reduced endotoxin(0.213±0.025)and TNF-αlevel(0.93±0.07)(P<0.05).The expression level of occludin protein was significantly lower in the intestinal mucosa of model group than that of control group(0.166±0.014),and berberine had promoted the expression of occludin protein in intestinal mucosa(0.055±0.009),but the difference was not statistically significant(P>0.05).At the same time,compared with the model group(7.29±0.47),the number of bacteroidetes in the control group(9.49±0.59)was decreased,while the number of bacteroidetes in the treatment group was increased(9.77±0.87).The number of escherichia coli(6.92±0.77)and faecalibacterium prausnitzii(8.70±0.62)in the model group were increased than control group(5.42±0.63,9.49±0.59),while the number of escherichia coli(6.34±0.71)and faecalibacterium prausnitzii(9.77±0.87)(P<0.05)was reduced with the intervention of berberine.Conclusion Berberine could effectively protect the intestinal barrier function in rats with NAFLD and the possible mechanism of action behind it may be the regulation of intestinal flora.