嗜热链球菌grx02发酵乳对大鼠酒精性肝损伤保护作用的实验研究

THE PROTECTIVE EFFECTS OF STREPTOCOCCUS THERMOPHILUS grx02 FERMENTED MILK ON ALCOHOLIC LIVER INJURY IN RATS

目的研究嗜热链球菌grx02对酒精性肝损伤大鼠肝细胞线粒体功能的保护作用,探讨其可能的作用机制。方法以56%酒精灌胃,复制大鼠酒精性肝损伤模型。Wistar大鼠随机分为对照组、模型组、东宝肝泰干预组、样品组、阳性对照组,每组10只。grx02发酵乳(高、中、低剂量)分别灌胃含乳酸菌数为108、107、106cfu/ml的脱脂乳发酵液14 ml/kg bw,连续6w。末次灌胃前晚禁食不禁水,灌胃1h后,对照组灌胃蒸馏水,其它各组灌胃50%酒精14ml/kg bw。12h后处死大鼠,检测血清中的谷氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、和甘油三酯(TG);提取肝细胞线粒体,测定丙二醛(MDA)含量,超氧化物歧化酶(SOD)、Na+-K+-ATPase,Ca2+-ATPase活力。结果与模型组比较,嗜热链球菌grx02可降低血清ALT、AST、TG水平,提高线粒体Na+-K+-ATPase,Ca2+-ATPase酶活性(P<0.05);且高剂量下各项指标优于其他组。结论嗜热链球菌grx02可改善酒精诱导急性肝损伤模型大鼠的肝功能,其可明显抑制酒精引发的肝细胞线粒体脂质过氧化反应,减轻自由基对线粒体的氧化损伤,并且它还可增强线粒体Na+-K+-ATPase、Ca2+-ATPase等ATP依赖酶的活性。

Objective To study the protection effects of lactobacillus Streptococcus thermophilus grx02 on the mitochodria of alcoholic liver injury in rats and explore its possible protection mechanism.Method Seventy Wistar rats were randomly divided into seven groups：control group,model group,Dongbao Gantai group,grx02 fermented milk groups（high,middle,low-dose） and positive control group.The control group and model group were gavaged with distilled water 14 ml/kg for 6 w.The Dongbao Gantai group,grx02 fermented milk groups were gavaged with 14 ml/kg of Dongbao Gantai,108,107,106 cfu/ml fermented milk for 6 w respectively.The positive control group was gavaged with 108 cfu/ml fermented milk 14 ml/kg.At the end of experiment,all groups except the conrol group were admimistend 14 ml/kg 50% ethanol at 1 hr after last gavage,while the control group was shill given 14 ml/kg distilled water.Then all rats were fasted for 12 h and then sacrificed.The serum levels of glutamate aminotransferase（ALT）,aspartate aminotransferase（AST）,and triglycerides（TG） were measured,while mitochondria malondialdehyde（MDA）,the activity of superoxide dismutase（SOD）,Na＋-K＋-ATPase,Ca2＋-ATPase of extracted mitochodria were also determined.Results Compared with the model group,Streptococcus thermophilus grx02 could decrease the serum levels of ALT,AST,TG,and increase the activity of Na＋-K＋-ATPase,Ca2＋-ATPase in mitochodria（P0.05）.Meanwhile,the indices of high-dose group were more potent than those of other groups.Conclusion Streptococcus thermophilus grx02 could improve the function of alcohol-induced liver injury,obviously suppress the action of lipid peroxidation of mitochodria induced by alcohol and enhance the activities of Na＋-K＋-ATPase, Ca2＋-ATPase.Streptococcus thermophilus grx02 has remarkable protective effect on alcohol-induced liver injury by increasing the activity of ATP-dependent enzyme in mitochodria and reducing the injury.