丹参对局灶性脑缺血大鼠氧化应激反应的保护效应

Protective effects of salvia miltiorrhizae on oxidative stress in rats with focal cerebral ischemia

目的:探讨丹参注射液对大鼠局灶性脑缺血后氧自由基损伤的保护作用及其最佳剂量。方法:实验于2004-10-05/12-19在锦州医学院科学实验中心完成。将SD大鼠60只,随机均分为假手术组、模型组、丹参13.5g/kg组,4.5g/kg组1.5g/kg组,每组12只。除正常组不插入线栓外,其余4组均采用线栓法制备大鼠大脑中动脉阻塞模型,术前3d及30min分别给予丹参3个剂量组腹腔注射丹参13.5g/kg,4.5g/kg,1.5g/kg。术后24h用5级评分法判定神经功能缺损,生化法测定脑组织匀浆中超氧化物歧化酶、丙二醛及病理组织切片的变化。结果:经补充60只大鼠进入结果分析。①模型组神经功能缺损评分显著高于假手术组[2.50±0.80,0.00,P<0.01];丹参13.5g/kg组,4.5g/kg组,1.5g/kg组神经功能缺损评分显著低于模型组[(1.67±0.65),(1.58±0.52),(1.50±0.80),(2.50±0.80),P<0.05],其中以1.5g/kg组最为显著(P<0.01)。②丹参13.5g/kg组,4.5g/kg组,1.5g/kg组与模型组相比,海马区神经细胞肿胀程度明显减轻,且海马CA1区神经细胞存活数明显增多[(75.3±4.1)/高倍视野,(76.3±5.0)/高倍视野,(82.5±7.1)/高倍视野,(62.8±6.8)/高倍视野,P<0.01]。③丹参13.5g/kg组,4.5g/kg组,1.5g/kg组均能明显增强脑组织中总超氧化物歧化酶活性,与模型组比较有显著差异[(55.32±6.39),(50.55±5.87),(51.44±7.06),(39.28±5.67)U/mg;P<0.01]。丹参1.5g/kg组与丹参13.5g/kg组,4.5g/kg组比较,显著增强锰超氧化物歧化酶的活性[(33.90±5.10),(34.13±3.85),(42.49±2.61)U/mg;P<0.05]。④丙二醛含量:丹参4.5g/kg组,13.5g/kg组均能明显降低丙二醛含量,与模型组比较有显著差异[(11.13±5.49),(11.73±6.87),(21.54±10.50)μmol/g;P<0.05],以1.5g/kg组更为显著[(9.96±4.08)μmol/g,P<0.01]。结论:丹参可减少自由基的生成,对神经细胞的氧化损伤具有保护作用,且以小剂量组的保护作用更加明显,其作用机制可能与增强锰超氧化物歧化酶的活性有关。

AIM： To investigate the protective effects of salvia miltiorrhizae on focal cerebral ischemia and oxidative stress in rats and its optimal dose. METHODS： The experiment was completed in Scientific Research Center of Jinzhou Medical College from October 5 to November 20, 2004. Sixty healthy SD rats were randomly divided into the sham-operative group, facal cerebral ischcmia group and salvia miltiorrhizae groups of 1.5 g/kg, 4.5 g/kg and 13.5 g/kg with 12 in each group. Embolization thread was inserted into all the rats except those in the normal group for the establishment of model of middle cerebral artery occlusion. Three days and 30 minutes before MCAO, the rats in salvia-treatment groups were intra-abdominally injected with 1.5 g/kg, 4.5 g/kg and 13.5 g/kg of salvia mihiorrhizae. The neurological function was observed by a method of grading on a scale of 0-4 and the activity of superoxide dismutase （SOD） and contents of malondialdehyde （MDA） were measured after 24 hours＇ focal cerebral ischemia, as well as the histopathological changes of cerebral tissues. RESULTS： By supplement, 60 rats were involved in the result analysis. （1） Neurological deficit scores ： Compared with that of sham-operative group, the scores of isehemia group evidently increased; while the treatment with salvia miltiorrhizae （1.5 g/kg, 4.5 g/kg and 13.5 g/kg） significantly decreased neurological deficit scores [（1.67±0.65）, （1.58±0.52）, （1.50±0.80）, （2.50±0.80）, P 〈 0.051, especially for the dose of 1.5 g/kg （P〈0.01）. （2） Histopathological changes; The result showed that salvia could protect against celhdar edema in hippocampus. Moreover, compared with ischemia group, the number of survival neurons in the CA1 sectors of the hippocampus of salvia-treatment groups increased evidently [（75.3±4.1）/HP, （76.3±5.0）/HP, （82.5±7.1）/HP, （62.8±6.8）/HP, P〈0.01]（3） The salvia groups （1.5 g/kg, 4.5 g/kg and 13.5 g/kg） could respectively increase the activity of T-SOD, which were evidently differential with model groups [（55.32±6.39）, （50.55±5.87）, （51.44±7.06）, （39.28±5.67）, P 〈 0.01]. However, the salvia miltiorrhizae group of 1.5 g/kg was evidently different from those of 4.5 g/kg and 13.5 g/kg at the activity of Mn-SOD [（33.90±5.10）, （34.13±3.85）, （42.49±2.61） U/mg, P〈0.05], （4） The contents of MDA in salvia mihiorrhizae groups were observably reduced as compared with those in model group [（11.13±5.49）, （11.73±6.87）, （21.54±10.50） μmol/g, P 〈 0.05], especially for the dosage of 1.5 g/kg [（9.96±4.08） μmol/g, P 〈 0.01]. CONCLUSION： Salvia miltiorrhizae can reduce the product of free radical, protect nerve cell against oxidizing injury, especially .the protection of low dosage. The mechanism is possiblly related with increasing activity of Mn-SOD.