葛根素对帕金森病大鼠黑质组织BDNF,TrkB,caspase-3表达的影响

目的:研究葛根素对6-羟多巴胺(6-OHDA)致帕金森病大鼠黑质组织脑原性神经营养因子(BDNF),酪氨酸激酶B(TrkB),半胱氨酸天冬酶-3(caspase-3)表达的影响.方法:建立帕金森病大鼠模型,随机分成5组:模型组、左旋多巴阳性组及葛根素低、中、高剂量组.ig给予葛根素20,40,80 mg· kg-1,阳性组给予左旋多巴40 mg·kg-1,连续灌胃30 d.TUNEL检测法观察黑质神经细胞的凋亡情况,Western blot法检测黑质组织BDNF,TrkB表达.免疫组织化学法检测caspase-3表达.结果:与模型组比较,葛根素(20,40,80 mg· kg-1)有效地降低黑质组织神经细胞凋亡水平(11.94 ±2.57),(7.61±1.21),(4.35±0.36) cell· mm-2(P＜0.01).上调黑质组织中BDNF、TrkB蛋白表达20.45％,31.29％,45.36％；14.76％,27.65％,38.81％ (P ＜0.01).而caspase-3免疫阳性细胞数量明显减少(36.48 ±6.25),(22.74 ±4.03),(12.19±2.51)cell·mm-2(P＜0.01).结论:葛根素对6-OHDA所致PD大鼠黑质神经细胞具有保护作用,机制可能与通过神经修复或再生以及逆转细胞凋亡进程而改善黑质功能有关.

Effect of Puerarin on the Expressions of BDNF,TrkB,caspase-3 in Substantia Nigra Tissue of Parkinson's Rats

Objective:To investigate the effect of puerarin on the expressions of brain-derived neurotrophic factor(BDNF),tyrosin kinase B(TrkB), caspase-3 in substantia nigra tissue of Parkinson's rats induced by 6-hydroxydopamine (6-OHDA). Method: Rat parkinson model was established, themodeling rats were randomly divided into 5 groups: model group, L-dopa group (40 mg·kg^-1), low-, medium-and high-dosage groups of puerarin (20, 40, 80 mg·kg^-1). The drugs were intragastrically perfused daily for 30 consecutive days. The apoptosis of nerve cells in substantia nigra was observed by TUNEL assay. The expression of BDNF and TrkB in substantia nigra was assayed by Western blot analysis. The caspase-3 expression was tested by immunohistochemistry assay. Result: Compared with model control group, puerarin effectively reduced neuronal apoptosis levels in substantia nigra tissue of parkinson's rats (P<0.01), and up-regulated the BDNF, TrkB protein levels in substantia nigra tissue (P<0.01). The number of caspase-3 immunoreactive cells was significantly decreased. Conclusion: The results demonstrate that puerarin has protective effect on the neuronal cells in substantia nigra of PD rats induced by 6-OHDA, probably the mechanism may be linked to neuronic repair or regeneration and reverse the process of apoptosis to improve the functions in substantia nigra.