紫草素对缺血性脑卒中的抗氧化作用OA

Objective To study the antioxidant effect and mechanism of shikonin(SKI)on ischemic stroke(IS)rats.Methods Eighty SD rats were divided into sham-surgery group,model group,SKI group and nimodipine group(20 for each group)according to the random number table.After 3 days of drug intervention,the rat model of middle cerebral artery occlusion(MCAO)was established.Rats in SKI group were administered SKI at a dose of 25 mg/kg,rats in nimodipine group were administered nimodipine at a dose of 10.8 mg/kg,rats in sham-surgery group and model group were administered an equal volume of physiological saline.Administration was via intraperitoneal injection once a day for 3 days.All rats were scored for neurological deficits by the Longa method;cerebral infarct volume was assessed by TTC staining;neuronal morphology in the ischemic semidorsal zone and hippocampal region was detected by Niehl's staining;brain tissue Reactive Oxygen Species(ROS)was detected by the probe DCFH-DA;serum Malondialdehyde(MDA)content was detected by the TBA method;Total Superoxide Dismutase(T-SOD)content in serum was detected by hydroxylamine method;Total Antioxidant Capacity(T-AOC)in serum was detected by ABTS method;Western Blot was employed to detect Nrf2 and HO-1protein content in the brain tissue on the ischaemic side.Results Compared with the sham-surgery group,the model group showed severe neurological impairment,significantly enlarged cerebral infarction volume,increased serum MDA level(P<0.05),disorganised neuronal arrangement,reduced or even disappeared Nissl bodies,decreased serum T-SOD and T-AOC levels,and decreased protein expression of Nrf2 and HO-1 in brain tissue(P<0.001).Compared with the model group,the SKI group showed significant improvement in impaired neurological function,reduction in cerebral infarction volume(P<0.01)and serum MDA level(P<0.05),clear neuronal cytoplasm and nuclei,well-arranged Nissl bodies,and increased expression of serum T-SOD and T-AOC content,and protein content of Nrf2 and HO-1(P<0.01).Compared with the nimodipine group,the SKI group showed a lower neurological impairment score,decreases in cerebral infarction volume,serum MDA level(P<0.05),neuronal morphology was restored and showed a relatively well-ordered arrangement,the Nissl bodies became more well-defined,the serum T-SOD level(P<0.05)and T-AOC level(P<0.01)were increased,and protein content expression of brain tissues of Nrf2,HO-1 increased(P<0.05).Conclusion The protective effect of SKI against IS may be attributed to the reduction of oxidative damage in brain tissue via the regulation of the Nrf2/HO-1 signaling pathway.