Neuroprotective effects of Phoenixin-14 in a rat model of global cerebral ischemia/reperfusion injury

The neuroprotective efficacy of Phoenixin-14 (PNX-14) was evaluated in an experimental model of global cerebral ischemia/reperfusion (I/R) established in male Wistar albino rats. Particular emphasis was placed on its influence on oxidative stress and the molecular pathways associated with apoptotic and ferroptotic cell death. A total of 36 animals were randomly distributed into three experimental groups consisting of Sham, I/R, and I/R receiving PNX-14 treatment (n = 12/group). In the Sham group, carotid arteries were exposed without ligation. In the I/R and I/R + PNX-14 groups, bilateral carotid artery occlusion was applied for 30 min followed by 21 days of reperfusion. The I/R + PNX-14 group received daily intraperitoneal PNX-14 (50 µg/kg) for 21 days. Neurological reflex tests assessing motor, sensory, balance, and corneal responses were performed three days a week for three weeks. Ferroptosis and apoptosis-related markers, inflammatory biomarkers, oxidative stress parameters, and histopathological changes were analyzed. PNX-14 treatment significantly regulated ferroptosis-related markers (GPx4, SLC7A11, ACSL4, iron, and MDA) and increased intracellular glutathione levels, indicating reduced oxidative stress. Decreased NF-κB and IL-6 levels demonstrated suppression of inflammation. Apoptosis markers p53 and cleaved caspase-3 were marked decrease in the PNX-14-treated group compared with the untreated I/R group. Histopathological evaluation showed reduced neuronal degeneration, demyelination, pyramidal cell disorganization in the hippocampal CA1 region, and capillary proliferation. Additionally, infarct volume was markedly decreased following PNX-14 treatment. The present findings support the notion that PNX-14 may have a neuroprotective effects against various aspects of damage caused by I/R in an in vivo global cerebral I/R model.