Abstract WMP33: Synergistic Effect Of Dehydroascorbic Acid, Glutathione And Melatonin On Brain Endothelium Protection In Ischemic Rats

Abstract

Introduction: Stroke (cerebral ischemia) is the second leading cause of death worldwide. Antioxidant strategies have been used successfully to diminish ischemic cerebral tissue damage in animals but the utility of a pharmacological agent as a clinically relevant therapeutic strategy may depend, in part, on its ability to cross the BBB. To optimally improve the therapeutic window this present study investigated whether the intravenous administration of dehydroascorbic acid (DHA), glutathione (GSH) and melatonin potentially elevates the level of cerebroprotection. Methods: Male rats were subjected to 60 min middle carotid artery occlusion (MCAO) using an intraluminal filament. Single dose of DHA (100mg/kg/ml), glutathione (500 mg/kg/ml) and melatonin (10 mg/kg/ml) was administered intravenously immediately after MCAO at a time interval of 5 min each. Western blotting was performed to delineate the effects of antioxidant treatment on the proliferation and neurogenesis in the ischemic region. We also examined the neuroprotective dosing regimen of triple antioxidants treatment and its effects on the functional outcomes following cerebral ischemia. Results: Triple antioxidant treatment significantly reduced the infarct volume and improved behavioral performance evidenced by TTC staining and neurological test score results. The significant increase in the claudin-5 and occludine expressions in the antioxidant treatment group depicts the preservation of blood-brain barrier (BBB) integrity via a reduction in the enormous amount of stroke-induced free radical production. Moreover, treatment with triple antioxidants after stroke dramatically enhanced endogenous neurogenesis (doublecortin positive) and cell proliferation (ki67 positive) in the peri-infarct regions. These outcomes were in the favor of rescuing the damaged neurons at the injury site defining the neuroprotective effects of triple antioxidants treatment following experimental stroke. Conclusion: The results from this study demonstrate that triple antioxidant treatment prevents brain edema, BBB hyperpermeability, and tight junction proteins disruption, possibly through its antioxidant effects thereby offering optimal neuroprotection in rat MCAO model.