Intraperitoneal administration of thioredoxin decreases brain damage from ischemic stroke

• rhTrx-1 improves neurological deficits after ischemia/reperfusion injury.
• rhTrx-1 lowers infarct volume and apoptosis after ischemia/reperfusion injury.
• rhTrx-1 reduces oxidative stress after transient middle cerebral artery occlusion.
• rhTrx-1 downregulates HO-1 expression.

Recent studies demonstrate that Thioredixin (Trx) possesses a neuronal protective effect and closely relates to oxidative stress and apoptosis of cerebral ischemia injury. The present study was conducted to validate the neuroprotective effect of recombinant human Trx-1 (rhTrx-1) and its potential mechanisms against ischemia injury at middle cerebral artery occlusion (MCAO) in mice. rhTrx-1 was administrated intraperitoneally at a dose of 5, 10 and 20 mg/kg 30 min before MCAO in mice, and its neuronal protective effect was evaluated by neurological deficit score, brain dry–wet weight, 2,3,5-triphenyltetrazolium chloride (TTC) staining. The protein carbonyl content and HO-1 were detected to investigate its potential anti-oxidative and anti-inflammatory property, and the anti-apoptotic ability of rhTrx-1 was assessed by casepase-3 and TUNEL staining. The results demonstrated that rhTrx-1 significantly improved neurological functions and reduced cerebral infarction and apoptotic cell death at 24 h after MCAO. Moreover, rhTrx-1 resulted in a significant decrease in carbonyl contents and HO-1 against oxidative stress, which turned to be fast reduction during the first 24 h and tended to be stable from 24 h to 72 h after MCAO. The study shows that rhTrx-1 exerts an neuroprotective effect in cerebral ischemia injury. The anti-oxidative, anti-apoptotic and anti-inflammatory properties of rhTrx-1 are more likely to succeed as a therapeutic approach to diminish oxidative stress-induced neuronal apoptotic cell death in acute ischemic stroke.