Neuroprotective Effect of Fisetin Against the Cerebral Ischemia-Reperfusion Damage via Suppression of Oxidative Stress and Inflammatory Parameters

Abstract

It is well established that inflammatory reactions and oxidative stress play an imperial role in cerebral ischemia-reperfusion pathogenesis. Fisetin is a flavonoid and has an antioxidant and anti-inflammatory effect on various diseases. In this study, we have been working to examine the neuroprotective effect of fisetin in brain injuries triggered by cerebral ischemic-reperfusion and explore the potential role of nuclear factor kappa B (NF-κB) signaling. In vitro, fisetin was examined against the cell viability, lactate dehydrogenase (LDH) leakage, cytokines, and apoptosis after ischemia/reperfusion (I/R) induced in the cells. In vivo, I/R injury was induced in the brain via transient middle cerebral artery occlusion (2 h) and reperfusion (20 h). The infarction area, brain water content, and neurofunctional parameters were also estimated. Inflammatory cytokines and brain injury markers were scrutinized at the end of the study. Fisetin treatment alleviated cell injury and suppressed the inflammatory cytokines (interleukin-1 (IL-1), tumor necrosis factor- α (TNF-α), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), interleukin-16 (IL-6), and prostaglandin E₂ (PGE₂)) and antioxidant parameters in a dose-dependent manner. Fisetin significantly (P < 0.001) reduced the infarct volume, brain water content. Fisetin significantly (P < 0.001) suppressed the neurological parameters and inflammatory cytokines such as IL-1, TNF-α, iNOS, IL-1β, COX-2, IL-6, PGE₂, and oxidative markers in a dose-dependent manner. Fisetin significantly (P < 0.001) reduced the inflammatory mediators including NF-κB and intercellular adhesion molecule 1 (ICAM-1). Further studies also showed that fisetin significantly inhibited the NF-κB activity via inflammatory and antioxidant pathways. In conclusion, by suppressing inflammatory cytokines, fisetin protected the brain tissue against I/R injury, and this effect could be due to reduced NF-κB activity.

Keywords: antioxidant; cerebral ischemic-reperfusion; fisetin; inflammation; neuroprotective.