α-Lipoic Acid Promotes Neurological Recovery after Ischemic Stroke by Activating the Nrf2/HO-1 Pathway to Attenuate Oxidative Damage

Abstract

Background/Aims: Alpha-lipoic acid (α-LA) has been demonstrated to be protective against cerebral ischemia injury. Herein, we investigate the neuroprotective effect and underlying mechanisms of α-LA. Methods: In vivo study, α-LA was administered intravenously upon reperfusion of transient middle cerebral artery occlusion. Garcia score was used to evaluate neurologic recovery. Infarct volume was examined by TTC staining, and oxidative damage was evaluated by ELISA assay. In an in vitro study, neurons were pretreated with α-LA at different doses and then subjected to OGD. Lentiviral vectors were applied to knockdown nuclear factor-erythroid 2-related factor-2 (Nrf2) or heme oxygenase-1 (HO-1). Cell viability was measured using CCK8. Protein expression was evaluated using western blot, and immunofluorescence staining was assessed. Results: α-LA significantly reduced the infarct volume, brain edema, and oxidative damage and promoted neurologic recovery in rats. Pretreatment of α-LA caused an obvious increase in cell viability and a decrease in intracellular reactive oxygen species. Western blot analyses and immunofluorescence staining demonstrated a distinct increase in Nrf2 and HO-1 protein expression. Conversely, knockdown of Nrf2 or HO-1 resulted in the down-regulation of HO-1 protein and inhibited the neuroprotective effect of α-LA. Conclusion: α-LA treatment is neuroprotective and promotes functional recovery after ischemic stroke by attenuating oxidative damage, which is partially mediated by the Nrf2/HO-1 pathway.