Abstract:Objective:To study whether the neuroprotective effect of tibolone during cerebral ischemia injury is associated with its anti-apoptosis effect.Methods: A total of 30 healthy adult female Sprague Dawley rats were evenly randomized into sham-operated group,ovariectomized group,and tibolone group(0.25 mg/\[kg·d\]).Brain ischemia model was induced by left middle cerebral artery occlusion(MCAO) for 2 hours followed by 24 hours reperfusion.All animals were killed and the cerebral infarction volumes were determined by 2,3,5-triphenyltetrazlium chloride (TTC) staining and image analysis.Apoptotic cells were labeled by Terminal deoxynucleotidyl Transferase-mediated dUTP nick end labeling (TUNEL) .The expression of Bcl-2,Bax,and caspase-3 was analyzed by immunohistochemical SP method. Results: Compared with the sham-operated group(P<0.05),cerebral infarction volume was significantly reduced,TUNEL positive cells was significantly decreased(P<0.01),Bcl-2 positive cells were significantly increased,and Bax(P<0.01),caspase-3 postive cells were significantly reduced compared with tibolone treated groups (P<0.01).Conclusion: Tibolone can inhibit the neuron apoptosis following cerebral ischemia injury in OVX rats,displaying a neuroprotective effect.