Modulation of Nrf-2/HO-1/HIF-1α/TFAM pathways by Arbutin in rat model of cerebral ischemic stroke

Ischemic stroke (IS) reduces the blood flow to the brain regions that trigger oxidative stress-induced biochemical, behavioural, molecular, and cellular impairments. Current treatment strategies are limited due to their narrow therapeutic window as, there is an urgent need to identify alternative therapeutic strategies in clinical settings to promote beneficial outcomes in stroke patients. Current study, focused on the neuro-protective potential of Arbutin (AR) in ischemic brain injury via modulation in Nrf-2/HO-1/HIF-1α/TFAM pathway. MCAO surgery was performed for 90 min, followed by reperfusion on male wistar rats, and the drug was administered intra-peritoneally. Animals were then sacrificed to estimate infarct volume, brain edema, BBB permeability, oxidative stress, inflammation, mitochondrial dysfunction, gene expression along with behavioural and morphological studies at different time intervals, i.e., 24 h and 21 days post-stroke. The results revealed that AR treatment improved neurological functions by maintaining BBB integrity and reducing edema, infarct volume, oxidative stress, and neuro-inflammation. It also improved the mitochondrial functions by increasing the gene expression of HIF-1α and TFAM along with reducing caspase-3 activation and iNOS gene expression through enhancing Nrf-2/HO-1 expression that supports the antioxidant activity of AR. Further, strong binding affinity of AR with the Nrf2 as revealed by the docking studies, reinforces our finding especially given the lack of prior target specific investigations exploring the detailed patho-mechanism of IS. Overall, AR exerts neuro-protective effect by modulating the Nrf-2/HO-1/HIF-1/TFAM pathways leading to improved mitochondrial functions, enhanced neurological outcomes, and increased neuronal survival which underscore its potential to as a therapeutic candidate for the treatment of IS.