狗肝菜不同相对分子质量多糖对四氯化碳所致大鼠急性肝损伤的保护作用

目的:比较狗肝菜不同分子量多糖对四氯化碳所致大鼠急性肝损伤的保肝降酶作用,研究其可能的保肝机制.方法:将70只雄性SD大鼠随机分成模型、联苯双酯、狗肝菜总多糖(A组)、相对分子质量＜6000狗肝菜多糖(B组)、相对分子质量6000～10000狗肝菜多糖(C组)和相对分子质量＞10 000狗肝菜多糖(D组)和对照组；A组(250 mg· kg-1)、B组(500 mg· kg-1)、C组(150 mg·kg-1)和D组(300 mg· kg-1)、联苯双酯组(150 mg·kg-1)在造模前灌胃给药7d,其他各组用生理盐水对照；在末次给药1h除对照组外,均灌胃0.1％ CC14花生油(0.01 mL·g-1)建立大鼠急性肝损伤模型,对照组用生理盐水对照.于16 h行腹主动脉取血用于检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、总蛋白(TP)；肝组织中超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性、丙二醛(MDA)含量及肝脏病理形态学变化；计算肝脏指数(肝体比)、脾脏指数(脾体比)、肾脏指数(肾体比).结果:与正常对照组比较,模型组大鼠血清中ALT,AST,TP水平显著升高(P＜0.01),提示本实验模型成功.狗肝菜各多糖组大鼠血清ALT,AST活性降低与模型组比较有显著性差异(P＜0.01),A,B组可显著减少由于肝损伤造成的TP升高,与模型对照组比较,差异具有统计学意义(P＜0.05或P＜0.01),其中B组效果最佳；与模型对照组比较,A,B组升高SOD活性(P＜0.05或P＜0.01)；A,C组升高GSH-Px活性,(P＜0.01)；对于MDA含量狗肝菜多糖各部位组降低均具有统计学意义(P＜0.01)；模型肝组织大片坏死、淤血,狗肝菜多糖各给药组组织损伤程度明显降低,以B组效果最佳；对于肝脏指数,D组效果最优(P＜0.05).结论:狗肝菜各多糖组均对CCl4所致大鼠急性肝损伤效果显著,综合分析相对分子质量＜6 000组(B组)保肝效果最佳.

Hepatoprotective Effect of Dicliptera chinensis Polysaccharide with Diffent Molecular Weight on Carbon Tetrachloride-induced Acute Liver Injury in Rats

Objective: To compare the hepatoprotective effect of Dicliptera chinensi polysaccharide (DCH) with different molecular weight on carbon tetrachloride -induced acute liver injury in rats and its possible mechanism was evaluated. Method: Seventy male Sprague-Dawley rats were randomly divided into model,biphenyl dimethyl dicarboxylate treated group,the total polysaccharide of DCH treated group (Group A),the polysaccharide of DCH treated groups (Group B,Group C,Group D, which molecular weight is<6 000,6 000-10 000,>10 000)and normal control group. It should be lavaged during 7 day before established the model of Group A(250 mg·kg^-1),Group B(250 mg·kg^-1),Group C(250 mg·kg^-1),Group D(250 mg·kg^-1) and biphenyl dimethyl dicarboxylate treated group(250 mg·kg^-1),while other groups were controlled by administration of normal saline.One hour after the final intragastric administration,all rats apart from the rats in the normal control group were lavaged with 0.01% ip carbon-tetrachloride(CCl₄) with peanuts oil(10 mL·kg^-1) according to establish the model of acute liver injury in rats,while other groups were controlled by administration of normal saline.To detect the ALT,AST and TPA,serum sample were collected after 16 hours by aorta sampling. Result: Compared with the normal control group,the AST,TP and ALT in serum of rats in model group were significantly increased (P<0.01).The content of TP was reduced by the total polysaccharides of D. chinensis(the A group)(P<0.05 or P<0.01). The SOD activity was obviously increased by the molecular weight<6 000 group(the B group)(P<0.01). The GSH-Px activity was increased by the A group and the molecular weight 6 000-10 000 group(the C group)(P<0.01).Necrosis and passive congestion of hepatic tissue in model group were numerous.The injury of hepatic tissue were inhibited in different polysaccharide of DCH treated groups while the optimum effect is in Group B.The optimum effect of hepatic index appeared in Group D. Conclusion: It was significant that the inhibition of hepatic injury in the polysaccharide of DCH which had different molecular weight treated groups while the effect was the best when molecular weight<6 000.