当归多糖对大鼠肝性脑病的预防作用

Angelica sinensis polysaccharides prevents rat from hepatic encephalopathy

目的观察当归多糖(Angelica sinensis polysaccharides,ASP)对四氯化碳性肝硬化大鼠肝性脑病发生的预防作用,并探讨其机制。方法400ml/L四氯化碳皮下注射造模,分别给予蒸馏水(阴性组),乳果糖(50g∶100ml,阳性药物组),ASP10、20、40g/L溶液10ml.kg-1.d-1灌胃,连续14d后用内毒素(3mg/kg)诱导大鼠昏迷,观察注射内毒素后12h内各组大鼠昏迷发生时间和数量,测定各组大鼠的血氨、血清谷丙转氨酶(GPT)、谷草转氨酶(GOT)浓度,观察脑细胞凋亡情况和星形胶质细胞数量。结果各组大鼠血氨、GPT、GOT水平,脑细胞凋亡数和昏迷率,阴性组最高;ASP40g/L组的血氨、GOT水平和昏迷率均低于阳性药物组,ASP3个剂量组的脑细胞凋亡数均低于阳性药物组,而星形胶质细胞数阴性组最低,且ASP3个剂量组均高于阳性药物组。结论ASP可保护脑功能,减缓肝性脑病的发生,作用优于阳性药物乳果糖。其机制可能与降低血氨,改善肝功能,保存星形胶质细胞和神经元的活性有关。

Objective To investigate to the role of Angelica sinensis polysaccharides （ASP） against hepatic encephalopathy and explore the probable mechanism. Methods Sprague-Dawley rats were established into carbon tetrachloride （CCl4 ）-induced liver cirrhosis, then treated with distilled water （negative control）, lactulose （positive control）, ASP solution （10, 20 and 40 g/L respectively, intragastrically at dose of 10 ml · kg^-1 · d^-1） for ld days. On 15th day, all the survival rats were intraperitoneally injected with endotoxin （3 mg/ kg） once, then in the following 12 h, the rats that fall into coma were counted and the time period of coma was recorded. The blood plasma concentrations of ammonia, serum glutamate-pyruvate transaminase （GPT） and glutamic oxaloacetic transaminase （GOT） were determined. The apoptotic cerebral cells were dyed in situ by TUNEL. Glial fibrillary acidic protein （GFAP） in astrocytes was determined by immunohistochemical method. Then we counted the apoptotic cerebral cells and GFAP positive cells under light microscope. Results The survival rats in distilled water group were highest in the concentrations of ammonia, GPT and GOT, the amount of apoptotic cerebral cells, and coma rate than the rats in other groups. The rats in 40 g/L ASP group had the higher ammonia level, GOT concentration, coma rate than those in lactulose group. The rats in 3 ASP groups all had less apoptotic cerebral cells than those in lactulose group. As to GFAP, distilled water group had the lowest immunological activity, and the GFAP immunological positive cells of 3 ASP groups were all more than those in lactulose group. ConcLusion ASP, even more effective than lactulose, can protect rat brain function and delay the occurrence of hepatic encephalopathy, whose effects may be related to the decrease of blood am- monia, the amelioration of liver function as well as the protection of astrocyte function and neuronic activity.