Neuroprotective Properties of Picroside II in a Rat Model of Focal Cerebral Ischemia

The aim of this study was to explore the effect of picroside II on neuronal apoptosis and the expression of caspase-3 and poly ADP-ribose polymerase (PARP) following middle cerebral artery occlusion/reperfusion in male Wistar rats. Picroside II (10 mg/kg) was administered intravenously into the tail vein of the animals. The neurological function deficits were evaluated with the Bederson's test and the cerebral infarction volume was visualized with tetrazolium chloride (TTC) staining. The apoptotic cells were counted by in situ terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end labeling (TUNEL) assay. The immunohistochemistry stain and enzyme linked immunosorbent assay (ELISA) was used to determine the expressions of caspase-3 and PARP in brain tissue. The results indicated that rats in the control group showed neurological function deficit and cerebral infarction in ischemic hemisphere after two hours ischemia followed by 22 hours reperfusion. Caspase-3 and PARP expressions were also profound in the cortex, the striatum and the hippocampus, along with increased apoptotic cells in this group. Bederson's score, infarction volume, and expressions of caspase-3 and PARP, as well as apoptosis in the treatment group were, however, significantly decreased compared to those in the control group indicating that intravenous treatment with picroside II might be beneficial to inhibit neuronal apoptosis and, thus, to improve the neurological function of rats upon cerebral ischemia reperfusion injury.