scholarly journals Uric Acid Protects against Focal Cerebral Ischemia/Reperfusion-Induced Oxidative Stress via Activating Nrf2 and Regulating Neurotrophic Factor Expression

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Bai-liu Ya ◽  
Qian Liu ◽  
Hong-fang Li ◽  
Hong-ju Cheng ◽  
Ting Yu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Cerebral Ischemia ◽  
Neurological Deficit ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Tunel Staining ◽  
Expression Levels ◽  
Cerebral Ischemia Reperfusion ◽  
Nrf2 Signaling Pathway

The aim of this study was to investigate whether uric acid (UA) might exert neuroprotection via activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and regulating neurotrophic factors in the cerebral cortices after transient focal cerebral ischemia/reperfusion (FCI/R) in rats. UA was intravenously injected through the tail vein (16 mg/kg) 30 min after the onset of reperfusion in rats subjected to middle cerebral artery occlusion for 2 h. Neurological deficit score was performed to analyze neurological function at 24 h after reperfusion. Terminal deoxynucleotidyl transferase-mediated dNTP nick end labeling (TUNEL) staining and hematoxylin and eosin (HE) staining were used to detect histological injury of the cerebral cortex. Malondialdehyde (MDA), the carbonyl groups, and 8-hydroxyl-2′-deoxyguanosine (8-OHdG) levels were employed to evaluate oxidative stress. Nrf2 and its downstream antioxidant protein, heme oxygenase- (HO-) 1,were detected by western blot. Nrf2 DNA-binding activity was observed using an ELISA-based measurement. Expressions of BDNF and NGF were analyzed by immunohistochemistry. Our results showed that UA treatment significantly suppressed FCI/R-induced oxidative stress, accompanied by attenuating neuronal damage, which subsequently decreased the infarct volume and neurological deficit. Further, the treatment of UA activated Nrf2 signaling pathway and upregulated BDNF and NGF expression levels. Interestingly, the aforementioned effects of UA were markedly inhibited by administration of brusatol, an inhibitor of Nrf2. Taken together, the antioxidant and neuroprotective effects afforded by UA treatment involved the modulation of Nrf2-mediated oxidative stress and regulation of BDNF and NGF expression levels. Thus, UA treatment could be of interest to prevent FCI/R injury.

Effects of Normobaric Hyperoxia in a Rat Model of Focal Cerebral Ischemia—Reperfusion

2002 ◽  
Vol 22 (7) ◽  
pp. 861-868 ◽  
Author(s):  
Aneesh B. Singhal ◽  
Xiaoying Wang ◽  
Toshihisa Sumii ◽  
Tatsuro Mori ◽  
Eng H. Lo
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Protein Carbonyl ◽  
Blue Dye ◽  
Heme Oxygenase 1 ◽  
Normobaric Hyperoxia ◽  
Cerebral Ischemia Reperfusion ◽  
Carbonyl Formation

Recent studies suggest that normobaric hyperoxia can be beneficial, if administered during transient stroke. However, increased oxygenation theoretically may increase oxygen free-radical injury, particularly during reperfusion. In the present study, the authors assessed the benefit and risks of hyperoxia during focal cerebral ischemia and reperfusion. Rats were subjected to hyperoxia (Fio2 100%) or normoxia (Fio2 30%) during 2-hour filament occlusion and 1-hour reperfusion of the middle cerebral artery. At 24 hours, the hyperoxia group showed 70% (total) and 92% (cortical) reduction in infarct volumes as compared to the normoxia group. Levels of oxidative stress were evaluated using three indirect methods. First, since oxygen free radicals increase blood—brain barrier (BBB) damage, Evan's blue dye extravasation was quantified to assess BBB damage. Second, the expression of heme oxygenase-1 (HO-1), a heat shock protein inducible by oxidative stress, was assessed using Western blot techniques. Third, an immunoblot technique (“OxyBlot”) was used to assess levels of protein carbonyl formation as a marker of oxidative stress—induced protein denaturation. At 24 hours, Evan's blue dye extravasation per average lesion volume was similar between groups. There were no significant differences in HO-1 induction and protein carbonyl formation between groups, in the ipsilateral or contralateral hemispheres, at 6 hours and at 24 hours. These results indicate that hyperoxia treatment during focal cerebral ischemia—reperfusion is neuroprotective, and does not increase oxidative stress.

Protective Effect of Astragaloside on Focal Cerebral Ischemia/Reperfusion Injury in Rats

2010 ◽  
Vol 38 (03) ◽  
pp. 517-527 ◽  
Author(s):  
Yan-Yan Yin ◽  
Wei-Ping Li ◽  
Hui-Ling Gong ◽  
Fen-Fang Zhu ◽  
Wei-Zu Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cerebral Ischemia ◽  
Water Content ◽  
Neurological Deficit ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Content Increase ◽  
Protective Effects ◽  
Neurological Deficit Score ◽  
Cerebral Ischemia Reperfusion

This study was to observe the neurological protective effects of astragalosides (AST) on focal cerebral ischemia-reperfusion (I/R) injury in rats and to explore its possible mechanism. Male SD rats received right middle cerebral artery occlusion for 120 min and AST (40 mg/kg) was orally administered. The rats were decapitated 1, 3, 7, and 14 days after reperfusion. The neurological deficit score, infarct volume and water content of brain were measured; the activity of superoxide dismutase (SOD), lactate dehydrogenase (LDH) and nitric oxide synthase (NOS), and the content of malondialdehyde (MDA), lactate (LD) and nitric oxide (NO) of brain tissue were detected too. The expression of inducible nitric synthase (iNOS), nerve growth factor (NGF) and tropomyosin receptor kinase A (TrkA) mRNA were measured by RT-PCR or real-time PCR. AST could significantly reduce the neurological deficit score; infract volume and water content, increase SOD and LDH activities, decrease NOS activity and MDA, LD and NO content. AST treatment could down-regulate expression of iNOS mRNA, while, NGF and TrkA mRNA were up-regulated. Our data suggest that AST have the protective effects on focal cerebral ischemia in rats at the different reperfusion time points, the mechanism may be related to the antioxidation, regulated the expressions of iNOS, NGF and TrkA mRNA.

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