牛蒡子复方制剂对大鼠脑缺血再灌注损伤的保护作用

Protective effect of compound agent great burdock achene on cerebral ischemia/ reperfusion injury of rats

目的:探讨牛蒡子复方制剂(阿克亭)对大鼠局灶性脑缺血再灌注损伤的保护作用及其可能的机制。方法:①实验于2004-09/2005-01在哈尔滨医科大学动物实验中心及病理实验室完成。选用健康雄性Wistar大鼠84只。将大鼠随机分为6组:假手术组,模型组,神经节苷脂组及牛蒡子复方制剂大、中、小剂量组,每组14只,每组又随机分为再灌注1,24h2个时相点,每个时相点7只进行观察。②采用改良线栓法制作大脑中动脉缺血再灌注模型,每组模型均缺血30min,随机使其中的7只再灌注1h,另外7只再灌注24h。神经节苷脂组在缺血即刻腹腔注射神经节苷脂(购自TRBPharmaS.A,2mL/支,生产批号20037)30mg/kg,牛蒡子复方制剂(牛蒡子生药,3g/mL,生产批号20050618,由乌苏里江制药责任有限公司提供)大、中、小剂量组在缺血即刻分别腹腔注射牛蒡子复方制剂100,50,10mg/kg,模型组给予等量生理盐水。③于大鼠缺血30min再灌注1,24h进行神经病学评分(0分:无神经功能缺失症状,活动正常者;1分:不能伸展对侧前爪者;2分:爬行时出现向左转圈者;3分:行走时身体向偏瘫侧倾倒者;4分:不能自发行走,意识丧失者)。④采用苏木精-伊红染色,光镜下观察脑组织变性坏死程度。⑤采用免疫组化分析方法观察Caspase-3蛋白的表达变化。⑥多组间比较采用单因素方差分析,同一时间点两组间比较采用Dunnett-t检验,不同时间点的比较采用两样本t检验。结果:进入结果分析大鼠保持为84只。①神经病学评分:神经节苷脂组和牛蒡子复方制剂各剂量组明显低于模型组(t=-2.951～-5.477,P<0.05),牛蒡子复方制剂各剂量组与神经节苷脂组比较,差异不明显(P>0.05)。②病理形态改变:模型组再灌注1h可见部分神经细胞核浆分界不清,细胞水肿;模型组再灌注24h病灶中心区神经细胞脱失范围增大,梗死血管周围出现大片空泡区。神经节苷脂组及牛蒡子复方制剂各剂量组与模型组比较,坏死区缩小,神经元受损减轻。③脑组织Caspase-3阳性细胞数:模型组再灌注1和24h明显多于假手术组(t=23.221,25.025,P<0.01),模型组、神经节苷脂组、牛蒡子复方制剂各剂量组再灌注24h时明显多于再灌注1h(t=2.298～4.322,P<0.05);神经节苷脂组、牛蒡子复方制剂各剂量组再灌注1和24h明显少于模型组(t=-6.823～-15.917,P<0.01);牛蒡子复方制剂小剂量组明显多于神经节苷脂组和牛蒡子复方制剂大、中剂量组(t=6.080,6.336,P<0.01)。结论:Caspase-3在局灶性脑缺血再灌注大鼠脑组织中活性显著增高;神经节苷脂及牛蒡子复方制剂均能降低神经功能缺失评分、抑制Caspase-3的激活,提示其脑保护作用可能与抑制缺血区Caspase-3激活从而抑制细胞凋亡有关,牛蒡子复方制剂大中剂量抑制Caspase-3激活的作用强于小剂量,与神经节苷脂作用差异不明显。

AIM： To study neuroprotective effects and possible mechanisms of compound agent great burdock achene （aketing） on focal cerebral ischemia/reperfusion injury in rats. METHODS： ① The study was performed in the Center of Animal and the Pathological Laboratory of Harbin Medical University from September 2004 to January 2005. Totally 84 male Wistar rats were randomly divided into sham-operation group, model group, gaaglioside group, high-dose, middle-dose and low-dose compound agent great burdock athene groups with 14 in each group. Each group was divided into 2 subgroups： 1-hoar reperfusion group and 24-hour reperfusion group with 7 in each group. ② The focal cerebral ischemia/repeffusion model was established with llne embolism to block the right middle cerebral artery. Rats in each group were kept for 30 minutes of isehemia. Seven rats were reperfused for 1 hour and other 7 were reperfused for 24 hours. Rats in ganglioside group were injected with 30 mg/kg ganglioside at the same time of ischemia, Ganglioside was provided by TRB Pharma S.A （2 mL/tube, batch number： 20037）. 100 mg/kg, 50 mg/kg and 10 mg/kg compound agent great burdock athene were injected into rats in high-dose, middle-dose and low-dose compound agent great burdock achene groups respectively. Compound agent great burdock achcne was provided by Wusulijiang Pharmaceutical Company Limited （3 g/mL raw materials, batch number： 20050618）. Rats in model group were injected with the same dose of saline. ③ Neurological scores were recorded after 30-minute ischemia 1- and 2-hour reperfusion （0： none of loss of nerve function and normal activities; h unable unfolding bilateral anterior claws; 2： turning to left during crawling; 3： tuming to hemiplegia side during walking; 4： unable walking on one＇s own and loss of consciousness）.④ Staining with heamatine-eosin, degeneration and necrosis of brain tissue were observed under light microscope. ⑤ Expression of caspase-3 protein was detected with immunohistochemical method. ⑥ Differences among groups were compared with one-way analysis of variance, Dunnett-t test was used between two groups at the same time point, and t test was used at various time points. RESULTS： Totally 84 rats entered the final analysis. ① Neurological scores： Scores in ganglioside group and various dosage groups were lower that those in model group （t=-2,951 to -5.477, P 〈 0.05-0.01）, and there was no significant difference among various dosage groups and ganglioside group （P 〉 0.05）. ②Pathological changes： Unclear border and cellular edema were observed in partial nerve cell in model group after 1-hour repeffusion; lost value of nerve cell increased in focal center and plenty vacuoles were observed around infarct blood vessel in model group after 24-hour reperfusion. Area of necrosis was reduced and neuron injury was relieved in ganglioside group and various dosage groups of compound agent great burdock achcne as compared with those in model group. ③Number of caspase-3 positive cells： Numbers in model group after 1-hour and 24- hour reperfusion were more than those in sham-operation group （t=23.221, 25.025, P 〈 0.01）; numbers in model group, ganglioside group and various dosage groups of compound agent great burdock achene after 24-hour reperfusion were more than those after 1-hour reperfusion （t=2.298-4.322, P 〈 0.05-0.01）; numbers in ganglioside group and various dosage groups of compound agent great burdock achene after 1-hour and 24-hour reperfusion were less than those in model group （t= -6.823 to -15.917, P 〈 0.01）; numbers in low-dose group were more than those in ganglioside group, high-dose and middle-dose groups （t=6.080, 6.336, P 〈 0.01）. CONCLUSION： Activity of caspase-3 increases in brain tissue of rats with focal ＂cerebral ischemia/reperfusion injury. Both ganglioside and compound agent great burdock achene can decrease the scores of neurological impairment and inhibit activity of caspase-3. This suggests that protective effect of brain is possibly related with inhibiting activity of caspase-3 in ischemic area so as to inhibit apoptosis. Moreover, effect of compound agent great burdock achene at high and middle dosages on inhibiting activity of caspase-3 is greater than that at low dosage, and the difference from ganglioside is not significant.