Effect of One Week Treatment with Ginkgo biloba Extract (EGb761) on Ischemia-Induced Infarct Volume in Gerbils

2003 ◽  
Vol 31 (04) ◽  
pp. 533-542 ◽  
Author(s):  
Shu-Ying Chung ◽  
Ming-Fu Wang ◽  
Jing-Ying Lin ◽  
Ming-Cheng Lin ◽  
Hui-Ming Liu ◽  
...  

The present study was designed to evaluate the neuroprotective effects of Ginkgo biloba leaf extract (EGb761) in male gerbils subjected to focal cerebral ischemia produced by permanent occlusion of the right middle cerebral artery. In this study, gerbils were fed standard chow with or without EGb761 (100 mg/kg/day, i.g.) prior to cerebral ischemia for 1 week. Gerbils were anesthetized and craniectomized to expose the right middle cerebral artery (MCA). The right MCA was constricted with an 8-0 suture to produce a permanent ligation. Infarct volume was assessed by TTC (2,3,5-triphenyl-tetrazolium chloride) staining 24 hours after initiation of cerebral ischemia. Results showed that the EGb761 group had significant reduction of infarct volume 4 and 6 mm from the frontal pole by 40% and 30%, respectively when compared to the control group ( p < 0.05). Mean locomotor activity of gerbils was reduced 24 hours after the occlusion of the MCA in both groups. However, there was no difference in locomotor activity between groups either 30 minutes before or 24 hours after the occlusion ( p < 0.05).

2016 ◽  
Vol 39 (4) ◽  
pp. 1339-1346 ◽  
Author(s):  
Lichun Pei ◽  
Songyan Meng ◽  
Weigang Yu ◽  
Qiujun Wang ◽  
Fangfang Song ◽  
...  

Background: Peroxisome proliferator-activated receptor gamma (PPARγ) plays a critical role in protecting against distinct brain damages, including ischemia. Our previous data have shown that the protein level of PPARγ is increased in the cortex after middle cerebral artery occlusion (MCAO); PPARγ up-regulation contributes to PPARγ activation and is effective in reducing ischemic damage to brain. However, the regulatory mechanism of PPARγ after focal cerebral ischemia in rats is still unclear. In this study, we evaluated the effect of microRNA on PPARγ in rats subjected to MCAO. Methods: Focal cerebral ischemia was established by surgical middle cerebral artery occlusion; the protein level of PPARγ was detected by Western blotting; the level of microRNA-383 (miR-383) was quantified by real-time PCR; the neurological outcomes were defined by infarct volume and neurological deficits. Luciferase assay was used to identify the luciferase activities of PPARγ and miR-383. Results: We showed here that miR-383 level was down-regulated in the ischemic hemisphere of rats 24h after MCAO. Overexpression of miR-383 by miR-383 agomir increased infarct volume and aggravated neurological damage. Administration of miR-383 antagomir had the opposite effects. Furthermore, we found that PPARγ protein was down-regulated by miR-383 overexpression, and up-regulated by miR-383 inhibition both in rat model of MCAO and in primary culture cells. Finally, we found that miR-383 suppressed the luciferase activity of the vector carrying the 3'UTR of PPARγ, whereas mutation of the binding sites relived the repressive effect of miR-383. Conclusion: Our study demonstrated that miR-383 may play a key role in focal cerebral ischemia by regulating PPARγ expression at the post-transcriptional level, and miR-383 may be a potential therapeutic target for stroke.


2006 ◽  
Vol 34 (05) ◽  
pp. 803-817 ◽  
Author(s):  
Shu-Ying Chung ◽  
Fu-Chou Cheng ◽  
Ming-Shih Lee ◽  
Jing-Ying Lin ◽  
Ming-Cheng Lin ◽  
...  

Ginkgo biloba exerts many pharmacological actions. It possesses antioxidant properties, the ability of neurotransmitter/receptor modulation and antiplatelet activation factor. This research is designed to investigate the neuroprotective effects of long-term treatment with EGb761 (a standard form of the extract of Ginkgo biloba leaf) in combination with MgSO 4, FK506, or MK-801 on the infarct volume of male gerbils' brain induced by unilateral middle cerebral artery occlusion (MCAO). Thirty-five gerbils fed a standard diet were intragastrically given water or EGb761 (100 mg/kg/day) for one week. Five randomized groups were established: control ( n = 7), EGb 761 ( n = 8), EGb 761 + MgSO 4 ( n = 7), EGb 761 + FK 506 ( n = 7), and EGb 761 + MK -801 ( n = 6). The three drug-combination groups were injected with MgSO 4 (90 mg/kg), FK506 (0.5 mg/kg), or MK-801 (1 mg/kg), respectively 30 min before MCAO. Gerbils were anesthetized and craniectomized to expose the right middle cerebral artery (MCA). The right MCA was constricted with an 8-0 suture to produce a permanent ligation for 24 hours. Postmortem infarct volumes were determined by quantitative image analysis of 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain sections. Results showed that the total infarct volumes of the four treated groups either EGb761 alone or in combination with drugs were lower than the control group by 36.1% (EGb761 alone), 40.3% ( EGb 761 + MgSO 4), 35.3% ( EGb 761 + FK 506), and 56.4% ( EGb 761 + MK -801), respectively ( p < 0.01). The main affected areas of the brain in the four treated groups were significantly focused between 4 and 6 mm from the frontal pole, when compared to the control group ( p < 0.01). All animals in the five groups had infarctions in both cortex and subcortex. These results indicate that long-term pre-treatment of EGb761 administered either alone or in combination with drugs significantly effective neuroprotection on infarct volume in gerbil ischemic brains.


2001 ◽  
Vol 94 (4) ◽  
pp. 582-588 ◽  
Author(s):  
Yi Yang ◽  
Qiu Li ◽  
Marian T. Nakada ◽  
Tao Yang ◽  
Ashfaq Shuaib

Object. Antagonists of the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor complex are currently used for the treatment of acute coronary syndromes. The platelet GPIIb/IIIa mediates platelet aggregation, and blocking this receptor complex can reduce or prevent arterial thrombosis. To study the recanalization efficacy of a GPIIb/IIIa antagonist in treating cerebral ischemia, we investigated the therapeutic effects of murine 7E3 F(ab′)2 in a focal embolic cerebral ischemia model in rats. Methods. Focal cerebral ischemia was produced by introducing an autologous thrombus into the right side of the middle cerebral artery (MCA). Thirty male Wistar rats were randomly divided into three groups of 10 rats each: control, 7E3 F(ab′)2 administered 1 hour postischemia, and 7E3 F(ab′)2 administered 3 hours postischemia. Animals in the therapeutic groups received intravenous infusion of 6 mg/kg 7E3 F(ab′)2 at 1 or 3 hours following cerebral embolization. Brain infarct volume, neurobehavioral scores, duration of bleeding, and findings on angiograms of the MCA (before and after infusion) were assessed in all animals. Angiographic evaluation revealed full MCA recanalization in three of 10 animals in each 7E3 F(ab′)2 treatment group. Animals in these groups exhibited a significant reduction in infarct volume when compared with animals in the control group: 1) infarct volume 1 hour postischemia, 22 ± 13.9% (p = 0.005); 2) infarct volume 3 hours postischemia, 22.1 ± 14.8% (p = 0.008); and 3) infarct volume in control animals, 42.4 ± 16%. Postischemia treatment with 7E3 F(ab′)2 also improved the animal's neurobehavioral performance. The duration of bleeding significantly increased by more than two times, but there was no associated increase in intracerebral hemorrhage in any group. Conclusions. On the basis of their findings, the authors conclude that murine 7E3 F(ab′)2 is a potent and safe antiplatelet agent in this experimental focal embolic cerebral ischemia model. Neuronal lesions were significantly reduced when the treatment was delayed up to 3 hours.


2010 ◽  
Vol 30 (5) ◽  
pp. 354-362 ◽  
Author(s):  
Ravi Pratap ◽  
KK Pillai ◽  
Razia Khanam ◽  
Fakhrul Islam ◽  
Shibli Jameel Ahmad ◽  
...  

The present study was designed to test pretreatment multiple doses of irbesartan (IRB) 50 mg, aspirin (ASP) 100 mg and the combination of both drugs for 7 days on middle cerebral artery—occluded (MCAO) rats. Focal cerebral ischemia was induced by MCA occlusion for 2 hours followed by reperfusion for 22 hours. After 24 hours of ischemia, grip strength and locomotor activity tests were performed. Animals were immediately sacrificed, infarct volume was measured followed by the estimation of markers of oxidative stress in the whole brains. Locomotor activity and grip strength were improved in IRB- and ASP-treated rats. Infarct volume was reduced in both IRB and ASP pretreatment as compared with MCAO rats. An elevation of thiobarbituric acid reactive substance (TBARS) and a reduction in glutathione (GSH) and antioxidant enzymes viz. superoxide dismutase (SOD) and catalase were observed following MCAO. Pretreatment of IRB and ASP showed the reduction in TBARS, elevation in GSH, SOD and catalase levels as compared with MCAO rats. The protective effects of IRB, an angiotensin II receptor antagonist having affinity for AT1 receptor subtypes, could be due to inhibition of AT 1 receptor expression in addition to its neuroprotective and free radical scavenging properties in cerebral ischemia. Further, it may be possible that the combination of IRB and ASP may be useful as an add-on therapy and would yield beneficial effects, if administered immediately following the ischemia in reducing the severity of the neurological deficits. However, our results are preliminary, further studies with posttreatment of IRB and ASP are required to provide more firm view.


1996 ◽  
Vol 16 (4) ◽  
pp. 612-622 ◽  
Author(s):  
Ricardo Prado ◽  
Brant D. Watson ◽  
Weizhao Zhao ◽  
Hiroshi Yao ◽  
Raul Busto ◽  
...  

The potential of nitric oxide (NO) to influence positively or negatively the outcome of mechanically induced focal cerebral ischemia is still controversial. Recent evidence suggests that NO of vascular origin, whether synthesized from exogenously administered L-arginine (L-Arg) or from NO donor compounds, is beneficial but that of neuronal origin is not. However, the therapeutic potential of NO to ameliorate stroke induced by arterial thrombosis has not been reported. We assessed the therapeutic effect of L-Arg administration in spontaneously hypertensive rats (SHR) subjected to permanent photothrombotic occlusion of the distal middle cerebral artery (dMCA). The ipsilateral carotid artery was left unligated to enhance L-Arg delivery into the putative penumbral region. Local CBF (LCBF) was assessed at 30 min by the [14C]iodoantipyrine technique (n = 9), while histological infarct volumes and index of peripheral ischemic cell change were determined at 3 days (n = 7). Rats (n = 9) given 300 mg/kg L-Arg at 18 and 3 h before photothrombotic dMCA occlusion and at 5 min afterward displayed no significant differences in LCBF compared with animals (n = 8) injected with water (the carrier vehicle) and similarly irradiated. Infarct volumes were also similar, being 37.0 ± 9.7 mm3 (SD) in the vehicle-treated and 49.1 ± 17.2 mm3 (SD) in the L-Arg-treated groups (both n = 7), as were assessments of ischemic neuronal density in the penumbra. In contrast, L-Arg administered intravenously in a dose of 300 mg/kg to nonischemic SHR (n = 5) increased cortical CBF by ∼75% during a 70-min observation period. We conclude that thrombotic processes superimposed upon cerebral ischemia may facilitate tissue reactions that offset the potentially beneficial effect of L-Arg, and this caveat must be considered when proposing L-Arg for clinical treatment of focal thrombotic stroke.


2021 ◽  
Vol 4 (4) ◽  
pp. 592-612
Author(s):  
Ye Feng ◽  
Qian Xu ◽  
Raymond Tak Fai Cheung

Cerebral ischemia induces oxidative injury and increases the intracellular calcium ion concentration to activate several calcium-dependent proteases such as calpains. Calpain activation leads to various necrotic and apoptotic processes. Calpeptin is a potent, cell-permeable calpain inhibitor. As a strong antioxidant and free radical scavenger, melatonin shows beneficial effect in rodent models of focal cerebral ischemia when given prior to ischemia or reperfusion. This study was focused on the neuroprotective effects of melatonin and/or calpeptin given after onset of reperfusion. For this purpose, right-sided middle cerebral artery occlusion (MCAO) for 90 minutes followed by 24 or 72 hours of reperfusion was performed in male Sprague Dawley rats, then, melatonin 50 or 150 µg/kg, calpeptin 10, 15 or 50 µg/kg or a combination of melatonin 50 µg/kg plus calpeptin 15 or 50 µg/kg were injected via an intracerebroventricular route at 15 minutes after onset of reperfusion. Melatonin or calpeptin tended to reduce the relative infarct volume and significantly decreased the neurological deficit at 24 hours. The combination achieved a greater protection than each of them alone. Melatonin, calpeptin or the combination all decreased Fluoro-Jade B (FJB)+ degenerative neurons and cleaved/total caspase-3 ratio at 24 hours. These treatments did not significantly impact the density of surviving neurons and ED-1+ macrophage/activated microglia. At the 72-hour-reperfusion, melatonin or the combination decreased the relative infarct volume and neurological deficit. Nevertheless, only the combination reduced FJB+ degenerating neurons at 72 hours. In conclusion, a combination of melatonin and calpeptin exerted synergistic protection against post-reperfusion injury in a rat MCAO stroke model.


Stroke ◽  
1997 ◽  
Vol 28 (1) ◽  
pp. 176-180 ◽  
Author(s):  
Marilyn J. Cipolla ◽  
Anthony L. McCall ◽  
Nikola Lessov ◽  
John M. Porter

2004 ◽  
Vol 100 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Kazuhide Furuya ◽  
Nobutaka Kawahara ◽  
Kensuke Kawai ◽  
Tomikatsu Toyoda ◽  
Keiichiro Maeda ◽  
...  

Object. The intraluminal suture model for focal cerebral ischemia is increasingly used, but not without problems. It causes hypothalamic injury, subarachnoid hemorrhage, and inadvertent premature reperfusion. The patency of the posterior communicating artery (PCoA) potentially affects the size of the infarct. In addition, survival at 1 week is unstable. The authors operated on C57Black6 mice to produce proximal middle cerebral artery occlusion (MCAO) so that drawbacks with the suture model could be circumvented. Methods. The MCA segment just proximal to the olfactory branch was occluded either permanently or temporarily. After 1 hour of MCAO the infarct volume was significantly smaller than that found after 2 hours or in instances of permanent MCAO. The differences were assessed at 24 hours and 7 days after surgery (p < 0.05 and p < 0.001, respectively). The patency of the PCoA, as visualized using carbon black solution, did not correlate with the infarct size. Neurologically, the 1- and 2-hour MCAO groups displayed significantly less severe deficits than the permanent MCAO group on Days 1, 4, and 7 (p < 0.005 and p < 0.01, respectively). Although the infarct size, neurological deficits, and body weight loss were more severe in the permanent MCAO group, the survival rate at Day 7 was 80%. Conclusions. This model provides not only a robust infarct size (which is not affected by the patency of the PCoA), but also a better survival rate.


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