Astragaloside IV ameliorates cerebral ischemia-reperfusion injury via upregulation of PKA and Cx36

To determine the effects of astragaloside IV on cerebral ischemic-reperfusion injury in rats and to explore underlying mechanisms of brain protection.Sixty Sprague-Dawley rats were randomized into four groups: Sham, cerebral ischemia-reperfusion (I/R group), I/R+astragaloside IV (I/R+AST-IV group) and I/R+astragaloside IV+PKA kinase inhibitor H-89 (I/R+AST-IV+H-89 group). All I/R rats were subjected to 2 h cerebral ischemia, followed by 24 h reperfusion and scored for neurobehavior. Cerebral infarct volume, pathomorphological changes and brain apoptosis, in addition to changes in expression of Cx36, PKA, Bax and Bcl-2 proteins, were assessed.Astragaloside IV treatment reduced neurobehavioral score and percentage volume of cerebral infarct, reducing pathomorphological injury and brain apoptosis. Expressions of Cx36 and PKA protein were increased and the Bax/Bcl-2 ratio decreased. All astragaloside IV effects were reversed by the PKA inhibitor and H-89.Astragaloside IV attenuated cerebral I/R injury in rats by increasing Cx36 and PKA protein expression and reducing the Bax/Bcl-2 ratio.