RESUMO
OBJECTIVE: To investigate the neuroprotective effect of protocatechuic acid (PCA) on cell death/survival protein imbalance in a rat model of middle cerebral artery occlusion and reperfusion. METHODS: Focal ischemia was induced by middle cerebral artery occlusion in adult male Wistar rats and confirmed by measuring infarction of brain by 2,3,5-Triphenyltetrazolium chloride (TTC) staining. Rats were treated with vehicle or PCA at 10, 30 or 50 mg/kg dose intraperitoneally and subjected to neurological deficits or beam walk assessment at 24 h of reperfusion. Effective dose of PCA (50 mg/kg) was administered at 1, 2 and 3 h time point of post-ictus ischemia. Cellular damage and nuclear condensation was observed by haematoxylin and eosin (H and E) staining and Hoechst 33342 staining respectively. Additionally, immunohistochemical expression of caspase 3 and cAMP-response element binding protein (CREB) and their mRNA's were observed. RESULTS: PCA at 30 and 50 mg/kg significantly improved behavioural performance and reduced infarction. Maximum neuroprotective effect of PCA (50 mg/kg) was found at 1 h (early hours) post-ictus ischemia along with reduction in cellular damage and nuclear condensation. PCA increased CREB protein and it's mRNA, while suppressed caspase-3 protein and mRNA at 1 h of reperfusion injury. CONCLUSION: PCA exhibit the potential to prevent early hour (1h) reperfusion injury restoring balance of survival and death protein may offer a cost effective adjuvant therapy in stroke.
