Neuroprotective effects of α-lipoic acid on ischemia/reperfusion injury in global cerebral ischemia mouse model

Ischemia-reperfusion (I/R) injury, resulting from transient or permanent cerebral vessel occlusion, triggers oxidative stress, neuroinflammation, and blood-brain barrier (BBB) disruption, leading to progressive neuronal damage and cognitive decline. The hippocampus, due to its high metabolic demand and susceptibility to oxidative stress, is particularly vulnerable to I/R-induced injury. This study evaluated the neuroprotective effects of α-lipoic acid (α-LA), a potent antioxidant, using bilateral common carotid arteries occlusion/reperfusion (BCCAO/R) mouse model and an oxygen-glucose deprivation/reoxygenation in vitro model. In BCCAO/R mice, α-LA improved spatial memory without affecting motor activity and restored hippocampal tight junction proteins (Claudin-5 and Occludin) and antioxidant enzyme expression, indicating BBB stabilization and oxidative stress reduction. Although synaptic proteins (BDNF and PSD-95) were not restored, cognitive improvements suggest alternative protective mechanisms. In HT22 cells, α-LA decreased intracellular reactive oxygen species levels, enhanced viability, and inhibited apoptosis via decreased PARP cleavage and caspase-3 activation. These protective effects were linked to the activation of the Nrf2/ARE signaling pathway and the upregulation of its downstream antioxidant targets. Overall, α-LA demonstrated marked neuroprotective effects in ischemic models by reducing oxidative stress, preserving BBB integrity, and restoring hippocampal function, positioning it as a promising therapeutic candidate for ischemic brain injury.