Neuroprotection of Cytisine Against Cerebral Ischemia–Reperfusion Injury in Mice by Regulating NR2B-ERK/CREB Signal Pathway

The aim of the study was to elucidate the therapeutic effects of Cytisine (CYT) on cerebral ischemia–reperfusion injury in mice. Male ICR mice were pretreated with reagents (drug), and then subjected to 2 h focal cerebral ischemia and 24 h reperfusion. Morphologically, the histopathological impairment were estimated by the TTC, HE and TUNEL staining. The expression of GluN2B-containing NMDA receptor, phosphorylation of extracellular regulated protein kinases, total ERK, phosphorylation of cAMP-response element binding protein and total CREB were determined by immunofluorescence and Western blot assay, respectively. The mRNA expression of NR2B, ERK and CREB were quantified by the real-time RT-PCR. CYT significantly diminished the infarct size and neuronal apoptosis. Additionally, it ameliorated histopathological lesion dramatically. CYT promoted the phosphorylation of ERK, CREB and their mRNA expression. In contrast, the expression of NR2B was suppressed in concomitant with the down-regulation of genes. The overall results thus far suggest that CYT confers the neuroprotection against cerebral I/R injury by regulating the NR2B-ERK/CREB signal pathway.