Bergenin has neuroprotective effects in mice with ischemic stroke through antioxidative stress and anti-inflammation via regulating Sirt1/FOXO3a/NF-κB signaling

Objective Bergenin (BGN) is a C-glycoside of 4-O-methylgallic acid with anti-inflammatory, antioxidant, and tissue-repairing abilities. Here, we probed the roles and mechanisms of BGN in ischemic stroke-mediated cerebral injury. Methods The middle cerebral artery occlusion (MCAO) model was established in mice, which were injected intraperitoneally with varying concentrations of BGN (10, 20, and 40 mg/kg). The modified neurological severity score (mNSS) and the water maze experiment were adopted to evaluate mice's neural functions (movement and memory). The brain edema was assessed by the dry and wet method. TdT-mediated dUTP nick end labeling (TUNEL)-labeled apoptotic neurons and Iba1-labeled microglia in the cortex were measured by immunohistochemistry (IHC). Quantitative reverse transcription-PCR and ELISA were implemented to determine the expression of inflammatory cytokines (TNF alpha, IL-1 beta, and IL-6), neurotrophic factors (BDNF and VEGF), and oxidative stress factors (SOD and MDA) in brain tissues. The profiles of Sirt1, FOXO3a, Nrf2, NF-kappa B, and STAT6 in brain tissues were checked by western blot. Results BGN significantly improved MCAO mice's cognitive, learning, and motor functions, reduced brain edema, hampered the production of inflammatory factors and oxidative stress mediators, and suppressed neuronal apoptosis. Additionally, BGN dampened the expression of proinflammatory cytokines and upregulated neurotrophic factors and oxidative stress factors in ischemic brain tissues of MCAO mice. Meanwhile, BGN reduced the expression of inflammatory cytokines and oxidative stressors in oxygen-glucose deprivation/reoxygenation-induced BV2 microglia. Further mechanistic studies revealed that BGN concentration dependently elevated the profiles of Sirt1, FOXO3a, STAT6, and Nrf2, and abated the NF-kappa B phosphorylation. Conclusion BGN protects against ischemic stroke in mice by boosting the Sirt1/FOXO3a pathway, suggesting its potential as a therapeutic agent for ischemic stroke.