Study On The Protective Mechanisms Of Qileng Decoction In The Focal Cerebral Ischemia Reperfusion Injury From Calpain Pathway

Objective: To study the protective effects of QiLeng decoction(QLD) andQiLengQuYangYin decoction(QLQYYD) on the focal cerebral ischemia reperfusion injury, andcompare the difference of the effects between them.Methods: The rats were randomly divided into five groups including blank control group,sham-operation control group, model group, QLD group and QLQYYD group. The model offocal cerebral ischemia reperfusion injury was induced by the modified method of threadembolizing cerclage in rats, than the neurologic scores were evaluated, and the pathomorphologychanges were observed by using the HE dyeing and Nissl dyeing. The expression of calpainl,calpastatin and fodrin at different time points were observed by immunohistochemical method.The expression of calpainl-mRNA was examined using the method of in situ hybridizationhistochemistry (ISH).Results: (1) HE dyeing: The cerebral tissues in blank control group and sham-operationcontrol group are normal, while those in the model group shows ischemia. The cerebral tissues inQLD group and QLQYYD group (both of them was obtained at 24h point after reperfusion) arebetter than the model group, and the QLD group is better than QLQYYD group. (2) Nissl dyeing:The cerebral tissues in the blank control group and the sham-operation control group areuniformity in colour, and neurons are normal. The neurons in model group are deformed,disappeared or irregular shape; the decrease of nissl bodies and the distored neurons bothoccurred in QLD and QLQYYD groups, but the circses are better than the model group, and theQLD group is better than QLQYYD group.(3) The expression of calpainl: there was very lowlevel of expression of calpainl in blank control group and sham-operation control group, themodel group had higher level of expression than the QLD and the QLQYYD groups, and thelevel of expression in QLD group was lower than in QLQYYD group.(4) The expression ofcalpastatin: the model group had lower level of expression compared to those in the other fourgroups, and the level of expression in QLD group increased compared with those in theQLQYYD group.(5) The expression of fodrin: the level of expression in model group wassignificantly lower than in the other four groups, and the level of expression in QLD group washigher as compared with those in the QLQYYD group. (6) The expression of calpainl-mRNA: there was very low level of expression in blank control group and sham-operation control group,the level of expression in the model group was higher than in the QLD and the QLQYYD group,and the level of expression in QLD group fell compared with those in QLQYYD group.Conclusion: QLD and QLQYYD can restrict the activation of calpainl after the focalcerebral ischemia reperfusion injury by promoting the activity of calpastatin. And they canrepress the activity of calpainl and decrease the degradation of fodrin, so as to play a role inprotecting the neuron after focal cerebral ischemia reperfusion injury. It proves that both QLDand QLQYYD can protect the neurons after the focal cerebral ischemia reperfusion injury byblocking the signal transduction path of calpainl, and QLD has better therapeutic effect whencompared with the QLQYYD. It indicates that adding nourishing yin(NY) herbs in the formulaof invigorating qi(IQ) and activating blood circulation(ABC) is an effective meassure for treatingfocal cerebral ischemia reperfusion injury.