Isofraxidin Attenuates Ischemia/Reperfusion‐Induced Neuroinflammation and Oxidative Stress Via Modulation of the TLR4/NF‐κB Signaling Pathway in Male Animal Model

ABSTRACT Background Cerebral ischemia reperfusion (CIR) is a condition of brain, which is occurred due to insufficient supply of blood. Isofraxidin is a naturally occurring coumarin derivative which showed the strong anti‐inflammatory and antioxidant effect in various disease animal models. Its neuroprotective effects against ischemia/reperfusion (I/R)‐mediated injuries, however, have not been investigated. The current study was to scrutinize the neuroprotective effect of Isofraxidin against the CIR in rats. Methods The Swiss Albino Wistar rats (sex‐male, 42 rats) were randomly selected for this study and transient occlusion of the middle cerebral artery was performed (1 h) for the induction of ischemia followed by reperfusion (24 h). Neurological score, brain water content, brain edema, infarct volume, nitric oxide (NO), myeloperoxidase (MPO), evans blue leakage, antioxidant, inflammatory, cytokines parameters and matrix metalloproteinases (MMP) level were estimated. Results Isofraxidin (7.5, 15 and 30 mg/kg) suppressed the brain edema (56.93%, 33.92%, 12.9%) neurological score (3.37, 2.76, 1.5), infarct volume (40.43%, 23.08%, 13.02%), evans blue leakage (4.32 μg/g tissue, 2.68 μg/g tissue, 1.35 μg/g tissue) and brain water content (72.95%, 54.66%, 40.38%) in the CIR group rats. CIR rats treated with Isofraxidin (7.5, 15 and 30 mg/kg) significantly ( p < 0.001) altered the level of clusterin (305.17 μg/mL, 197 μg/mL, 110.65 μg/mL), neuron‐specific enolase (14.04 ng/mL, 8.08 ng/mL, 6.02 ng/mL), NO (0.78 μmol/mg, 0.51 μmol/mg, 0.39 μmol/mg) and MPO (1.81 U/mg protein, 1.41 U/mg protein, 0.87 U/mg protein) along with the modulation of antioxidant parameters. Isofraxidin (7.5, 15 and 30 mg/kg) significantly ( p < 0.001) altered the level of cytokines such as tumor necrosis factor‐α (29.53 pg/mg, 19.55 pg/mg, 11.52 pg/mg), interleukin‐1β (19.22 pg/mg, 12.36 pg/mg, 7.01 pg/mg), 2 (234.33 pg/mg, 151.66 pg/mg, 71.27 pg/mg), 6 (37.23 pg/mg, 30.55 pg/mg, 21.91 pg/mg), 9 (89.06 pg/mg, 48.51 pg/mg, 26.29 pg/mg) and 10 (10.98 pg/mg, 19.38 pg/mg, 28.86 pg/mg). CIR group rats treated with isofraxidin (7.5, 15 and 30 mg/kg) decreased the level of cyclooxygenase‐2 (32.05 pg/mg, 19.91 pg/mg, 12.83 pg/mg), prostaglandin (33.88 pg/mg, 21.01 pg/mg, 12.13 pg/mg), inducible nitric oxide (31.01 pg/mg, 19.51 pg/mg, 10.16 pg/mg), vascular endothelial growth factor (41.71 pg/mg, 28.55 pg/mg, 16.19 pg/mg) and nuclear kappa B factor (52.91 pg/mg, 36.16 pg/mg, 16.17 pg/mg), respectively. Isofraxidin (7.5, 15 and 30 mg/kg) treatment altered the mRNA expression of COX‐2, LOX‐1, iNOS, NF‐κB, Bax, Bcl‐2, caspase‐3, TRL4, syndecan‐1, CSF, aquaportin‐1, OCT3 and RFX1. Conclusion Isofraxidin treatment exhibited brain protective against cerebral ischemia reperfusion via suppression of free radical and inflammatory reaction.