Rat Pial Microvascular Responses to Transient Bilateral Common Carotid Artery Occlusion and Reperfusion: Quercetin's Mechanism of Action

THE NEUROPROTECTIVE EFFECT OF TOCILIZUMAB IN BRAIN ISCHEMIA REPERFUSION INJURY

OBJECTIVE

The aim: This research was conducted to assess the possible neuroprotective effect of Tocilizumab in brain ischemic reperfusion injury in rats.

PATIENTS AND METHODS

Materials and methods: 24 adult Sprague-Dawley rats were divided into four groups randomly. The sham group was given anesthesia at the same time as the other groups and was in the same condition as the other groups. Control group: 1 h of ischemia followed by 4 h of reperfusion. The vehicle group was the same as the control, but they were given the vehicle intraperitoneally (1 ml/kg of 0.9 % NaCl) for 7 days before the ischemia. The treatment group as the control group, but they were given tocilizumab (8 mg/ kg) intraperitoneally for 7 days before ischemia.

RESULTS

Results: control group, inducing ischemia/reperfusion increased infarction size considerably (p<0.001), when comparison to the control and vehicle groups, tocilizumab at dose (8 mg/kg) showed a significantly (p<0.001) smaller infraction area.

CONCLUSION

Conclusions: In a cerebral ischemia/reperfusion, a reduction in infarction area in injected with Tocilizumab medication was considered neuroprotective for cerebral ischemia/reperfusion.

Effects of a catechins-enriched diet associated with moderate physical exercise in the prevention of hypertension in spontaneously hypertensive rats

Hypertension represents the main risk factor for the onset of cardiovascular diseases. Pharmacological treatments to control hypertension have been associated with new treatments involving physical activity and/or the intake of natural components (nutraceuticals). We here report the effects produced by a combination of a natural component (catechins) and a moderate exercise program on the development of hypertension in spontaneous hypertensive rats compared with those of each individual treatment. Arterial blood pressure and heart rate were measured with a non-invasive method in 28 rats randomly assigned to four groups: rats subjected to moderate physical exercise; rats with a catechins-enriched diet; rats subjected to moderate physical exercise combined with a catechins-enriched diet; control, untreated-rats left to age. All treatments were applied for 6 weeks. The statistical analysis revealed that the three treatments significantly reduced the weekly increase in arterial blood pressure observed in control rats (SBP, P < 0.0001; DBP, P = 0.005). However, the reduction of arterial blood pressure induced by combined treatments was not higher than that induced by the single treatment, but more prolonged. All treatments showed strong antioxidative properties. Our data show that physical activity and a diet enriched with catechins individually have an important hypotensive effect, while the association did not produce a higher hypotensive effect than the single treatment, even if it was able to decrease blood pressure for a longer time. These findings have important implications for developing a protocol to apply in novel hypertension prevention procedures.

The Effects of Angiotensin II or Angiotensin 1-7 on Rat Pial Microcirculation during Hypoperfusion and Reperfusion Injury: Role of Redox Stress

Renin-angiotensin systems produce angiotensin II (Ang II) and angiotensin 1-7 (Ang 1-7), which are able to induce opposite effects on circulation. This study in vivo assessed the effects induced by Ang II or Ang 1-7 on rat pial microcirculation during hypoperfusion-reperfusion, clarifying the mechanisms causing the imbalance between Ang II and Ang 1-7. The fluorescence microscopy was used to quantify the microvascular parameters. Hypoperfusion and reperfusion caused vasoconstriction, disruption of blood-brain barrier, reduction of capillary perfusion and an increase in reactive oxygen species production. Rats treated with Ang II showed exacerbated microvascular damage with stronger vasoconstriction compared to hypoperfused rats, a further increase in leakage, higher decrease in capillary perfusion and marker oxidative stress. Candesartan cilexetil (specific Ang II type 1 receptor (AT₁R) antagonist) administration prior to Ang II prevented the effects induced by Ang II, blunting the hypoperfusion-reperfusion injury. Ang 1-7 or ACE2 activator administration, preserved the pial microcirculation from hypoperfusion-reperfusion damage. These effects of Ang 1-7 were blunted by a Mas (Mas oncogene-encoded protein) receptor antagonist, while Ang II type 2 receptor antagonists did not affect Ang 1-7-induced changes. In conclusion, Ang II and Ang 1-7 triggered different mechanisms through AT₁R or MAS receptors able to affect cerebral microvascular injury.

Geometric Features of the Pial Arteriolar Networks in Spontaneous Hypertensive Rats: A Crucial Aspect Underlying the Blood Flow Regulation

Background

Several studies indicate that hypertension causes major changes in the structure of the vessel wall by affecting the regulation of blood supply to the tissues. Recently, it has been observed that capillary blood flow is also considerably influenced by the structural arrangement of the microvascular networks that undergo rarefaction (reduction of the perfused vessel number). Therefore, this study aimed to assess the geometric arrangements of the pial arteriolar networks and the arteriolar rhythmic diameter changes in spontaneously hypertensive rats (SHRs).

Methods

Fluorescence microscopy was utilized to observe in vivo the pial microcirculation through a closed cranial window. Pial arterioles were classified according to Strahler’s method. The arteriolar rhythmic diameter changes were evaluated by a generalization short-time Fourier transform.

Result

Young SHRs showed four orders of vessels while the adult ones only three orders. The diameter, length, and branching number obeyed Horton’s law; therefore, the vessels were distributed in a fractal manner. Larger arterioles showed more asymmetrical branches than did the smaller ones in young SHRs, while in adult SHRs smaller vessels presented asymmetrical branchings. In adult SHRs, there was a significant reduction in the cross-sectional area compared with the young SHRs: this implies an increase in peripheral resistance. Young and adult age-matched normotensive rats did not show significant alterations in the geometric arteriolar arrangement with advancing age, both had four orders of arteriolar vessels, and the peripheral resistance did not change significantly. Conversely, the frequency components evaluated in arteriolar rhythmic diameter changes of young and adult SHRs showed significant differences because of a reduction in the frequency components related to endothelial activity detected in adult SHRs.

Conclusion

In conclusion, hypertension progressively causes changes in the microarchitecture of the arteriolar networks with a smaller number of vessels and consequent reduced conductivity, characteristic of rarefaction. This was accompanied by a reduction in the formation and release of independent and dependent – endothelial nitric oxide components regulating arterial vasomotion.

Evaluating the Velocity and Extent of Cortical Venous Filling in Patients With Severe Middle Cerebral Artery Stenosis or Occlusion

Objective: To investigate the velocity and extent of cortical venous filling (CVF) and its association with clinical manifestations in patients with severe stenosis or occlusion of the middle cerebral artery (MCA) using dynamic computed tomography angiography (CTA). Methods: Fifty-eight patients (36 symptomatic and 22 asymptomatic) with severe unilateral stenosis (≥70%) or occlusion of the MCA M1 segment who underwent dynamic CTA were included. Collateral status, antegrade flow, and CVF of each patient were observed using dynamic CTA. Three types of cortical veins were selected to observe the extent of CVF, and the absence of CVF (CVF-) was recorded. Based on the appearance of CVF in the superior sagittal sinus, instances of CVF, including early (CVF₁), peak (CVF₂), and late (CVF₃) venous phases, were recorded. The differences in CVF times between the affected and contralateral hemispheres were represented as rCVFs, and CVF velocity was defined compared to the median time of each rCVF. Results: All CVF times in the affected hemisphere were longer than those in the contralateral hemisphere (p < 0.05). Patients with symptomatic MCA stenosis had more ipsilateral CVF- (p = 0.02) and more delayed CVF at rCVF₂ and rCVF₂₁ (rCVF₂-rCVF₁) (p = 0.03 and 0.001, respectively) compared to those with asymptomatic MCA stenosis. For symptomatic patients, fast CVF at rCVF₂₁ was associated with poor collateral status (odds ratio [OR] 6.42, 95% confidence interval [CI] 1.37-30.05, p = 0.02), and ipsilateral CVF- in two cortical veins was associated with poor 3-month outcomes (adjusted OR 0.025, 95% CI 0.002-0.33, p = 0.005). Conclusions: Complete and fast CVF is essential for patients with symptomatic MCA stenosis or occlusion. The clinical value of additional CVF assessment should be explored in future studies to identify patients with severe MCA stenosis or occlusion at a higher risk of stroke occurrence and poor recovery.

Systematic Understanding of the Mechanisms of Flos Chrysanthemi Indici-mediated Effects on Hypertension via Computational Target Fishing

AIMS AND OBJECTIVE

Hypertension-induced stroke and coronary artery disease are significant causes of global morbidity and mortality. Metabolic hypertension has recently become the leading cause of hypertension. Flos Chrysanthemi Indici (CIF) has a long history as a treatment of hypertension as part of traditional Chinese medicine. However, its mechanisms of activity remain largely unknown. This study was aimed to uncover the potential anti-hypertensive mechanisms of CIF based on network pharmacology.

MATERIALS AND METHODS

In this research, a systems pharmacology approach integrating the measurement of active compounds, target fishing, gene screening, Gene Ontology (GO) pathway analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthology Based Annotation System (KOBAS) database analysis, and compound-target network construction were performed to explore the anti-hypertensive mechanisms of CIF.

RESULTS

These studies revealed that 12 bioactive compounds in CIF had good druggability, 5 of which were flavonoids. After screening, 8 of those 12 bioactive compounds interacted with 118 hypertensionrelated target genes, which were mapped to 218 signal pathways. Network analysis showed that these targets were associated with improving insulin resistance, improving vascular function, inhibiting renninangiotensin- aldosterone system (RAAS), inhibiting the sympathetic nervous system (SNS) and regulating other physiological processes.

CONCLUSION

In summary, CIF is predicted to target multiple proteins and pathways to form a network that exerts systematic pharmacological effects in order to regulate blood pressure and metabolic disorder.

Effect of Quercetin on PC12 Alzheimer's Disease Cell Model Induced by Aβ 25-35 and Its Mechanism Based on Sirtuin1/Nrf2/HO-1 Pathway

Objective

This study is aimed at studying the effect of quercetin on the Alzheimer disease cell model induced by Aβ_25-35 in PC12 cells and its mechanism of action.

Methods

The AD cell model was established by Aβ_25-35. Quercetin was used at different concentrations (0, 10, 20, 40, and 80 μmol/L). The morphology of cells was observed, and the effect on cell survival rate was detected by the MTT method. Cell proliferation was detected by the SRB method. The contents of LDH, SOD, MDA, GSH-Px, AChE, CAT, and T-AOC were detected by kits. The expression of sirtuin1/Nrf2/HO-1 was detected by RT-qPCR and Western blot.

Results

PC12 cells in the control group grew quickly and adhered well to the wall, most of which had extended long axons and easily grew into clusters. In the model group, cells were significantly damaged and the number of cells was significantly reduced. It was found that PC12 cells were swollen, rounded, protruding, and retracting, with reduced adherent function and floating phenomenon. Quercetin could increase the survival rate and proliferation rate of PC12 cells; reduce the levels of LDH, AChE, MDA, and HO-1 protein; and increase the levels of SOD, GSH-Px, CAT, T-AOC, sirtuin1, and Nrf2 protein.

Conclusion

Quercetin can increase the survival rate of PC12 injured by Aβ_25-35, promote cell proliferation, and antagonize the toxicity of Aβ; it also has certain neuroprotective effects. Therefore, quercetin is expected to become a drug for the treatment of AD.

The Pomace Extract Taurisolo Protects Rat Brain From Ischemia-Reperfusion Injury

Taurisolo^® is a pomace extract from Aglianico Grapes, a wine cultivar native to Campania (Southern Italy). It exhibits a very high polyphenolic content and, consumed as a nutraceutical, is effective in reducing the level of Trimethylamine N-oxide (TMAO), a cardiovascular disease risk factor marker. We here show the effects of Taurisolo^® on rat brain microvascular alterations induced by a diminution in cerebral blood flow (CBFD) for 30 min, due to bilateral common carotid artery occlusion, and subsequent blood flow restoration (CBFR) for 60 min. The rat pial microcirculation was investigated by intravital fluorescence microscopy through a parietal closed window implanted into the skull bone. The rat pial arterioles were classified according to Strahler’s ordering scheme, from smaller penetrating arterioles up to the larger ones. Western blotting analysis and mass spectrometry (MS)-based metabolomics were used to investigate the expression of endothelial nitric oxide synthase (eNOS) or the presence of peroxidized cardiolipin and several inflammatory mediators, respectively. Radical Oxygen Species (ROS) formation and neuronal loss were assessed. In rats CBFD and CBFR caused a decrease in arteriolar diameter, increase in fluorescent leakage and in adhesion of leukocytes to venular walls, reduction in the length of perfused capillaries and increment of ROS formation with large infarct size. Taurisolo^®, intravenously or orally administered, induced pial arteriolar dilation (up to >30% of baseline), prevented fluorescent leakage, adhesion of leukocytes, ROS formation, while facilitated capillary perfusion and significantly reduced infarct size. These effects were accompanied by an increase in eNOS expression. Mass-spectrometry metabolomics analysis detected a marked decrease in the amount of peroxidized cardiolipin and pronounced reduction in pro-inflammatory prostaglandins and thromboxane Txb2. Altogether, these results extend the nutraceutical potential of Taurisolo^® and suggest their eligibility for preventing brain damage due to ischemia-reperfusion injury.

Caffeine Modulates Spontaneous Adenosine and Oxygen Changes during Ischemia and Reperfusion

Adenosine is an endogenous neuroprotectant that modulates vasodilation in the central nervous system. Oxygen changes occur when there is an increase in local cerebral blood flow and thus are a measure of vasodilation. Transient oxygen events following rapid adenosine events have been recently discovered, but the relationship between adenosine and blood flow change during ischemia/reperfusion (I/R) has not been characterized. Caffeine is a nonselective adenosine receptor antagonist that can modulate the effects of adenosine in the brain, but how it affects adenosine and oxygen levels during I/R is also unknown. In this study, extracellular changes in adenosine and oxygen were simultaneously monitored using fast-scan cyclic voltammetry during bilateral common carotid artery occlusion (BCCAO) and the effects of a specific A2A antagonist, SCH 442416, or general antagonist, caffeine, were studied. Measurements were made in the caudate-putamen for 1 h of normoxia, followed by 30 min of BCCAO and 30 min of reperfusion. The frequency and number of both adenosine and oxygen transient events significantly increased during I/R. The specific A2A antagonist, SCH 442416 (3 mg/kg, i.p.), eliminated the increase in adenosine and oxygen events caused by I/R. The general adenosine receptor antagonist, caffeine (100 mg/kg, i.p.), decreased the frequency of adenosine and oxygen transient events during I/R. These results demonstrate that, during BCCAO, there are more rapid release events of the neuromodulator adenosine and correlated local oxygen changes, and these rapid, local effects are dampened by caffeine and other A2A antagonists.

Vanillic acid attenuates cerebral hyperemia, blood-brain barrier disruption and anxiety-like behaviors in rats following transient bilateral common carotid occlusion and reperfusion

Transient bilateral common carotid artery occlusion (tBCCAO), followed by reperfusion, is a model of transient global hypoperfusion. In the present study we aimed to investigate the probable effects of Vanillic acid (VA) on some physiological parameters including cerebral hyperemia, blood-brain barrier (BBB) disruption, anxiety behaviors and neurological deficits induced by bilateral occlusion of the common carotid arteries and reperfusion (BCCAO/R) in rats. Rats were randomly divided into four groups; Sham, BCCAO/R, VA and VA+ BCCAO/R. Chronic cerebral hypoperfusion was induced after 2 weeks of pretreatment by VA. Subsequently, sensorimotor scores, elevated plus maze tests, cerebral hyperemia, and BBB disruption were evaluated 72 h after 30 min of BCCAO. Pretreatment of rats by VA improved sensory motor signs, anxiolytic behavior in BCCAO/R rats compared with untreated rats (p < 0.05). Further, VA attenuated reactive hyperemia and BBB disruption in BCCAO/R rats compared with untreated rats (p < 0.01). To our knowledge, this study is the first to reveal VA could attenuate reactive hyperemia and improve BBB disruption following BCCAO/R, and could improve neurological scores and anxiety like behaviors in this model of cerebral hypoperfusion. These results suggest that VA could be a promising pretreatment agent in cerebral hypoperfusion.

Acute administration of beta-caryophyllene prevents endocannabinoid system activation during transient common carotid artery occlusion and reperfusion

BACKGROUND

The transient global cerebral hypoperfusion/reperfusion achieved by induction of Bilateral Common Carotid Artery Occlusion followed by Reperfusion (BCCAO/R) has been shown to stimulate early molecular changes that can be easily traced in brain tissue and plasma, and that are indicative of the tissue physiological response to the reperfusion-induced oxidative stress and inflammation. The aim of the present study is to probe the possibility to prevent the molecular changes induced by the BCCAO/R with dietary natural compounds known to possess anti-inflammatory activity, such as the phytocannabinoid beta-caryophyllene (BCP).

METHODS

Two groups of adult Wistar rats were used, sham-operated and submitted to BCCAO/R. In both groups, 6 h before surgery, half of the rats were gavage-fed with a single dose of BCP (40 mg/per rat in 300 μl of sunflower oil as vehicle), while the second half were pre-treated with the vehicle alone. HPLC, Western Blot and immunohistochemistry were used to analyze cerebral cortex and plasma.

RESULTS

After BCCAO/R, BCP prevented the increase of lipoperoxides occurring in the vehicle-treated rats in both cerebral cortex and plasma. In the frontal cortex, BCP further prevented activation of the endocannabinoid system (ECS), spared the docosahexaenoic acid (DHA), appeared to prevent the increase of cyclooxygenase-2 and increased the peroxisome-proliferator activated receptor-alpha (PPAR-alpha) protein levels, while, in plasma, BCP induced the reduction of arachidonoylethanolamide (AEA) levels as compared to vehicle-treated rats.

CONCLUSIONS

Collectively, the pre-treatment with BCP, likely acting as agonist for CB2 and PPAR-alpha receptors, modulates in a beneficial way the ECS activation and the lipoperoxidation, taken as indicative of oxidative stress. Furthermore, our results support the evidence that BCP may be used as a dietary supplement to control the physiological response to the hypoperfusion/reperfusion-induced oxidative stress.

Preventive Effects of Resveratrol on Endocannabinoid System and Synaptic Protein Modifications in Rat Cerebral Cortex Challenged by Bilateral Common Carotid Artery Occlusion and Reperfusion

This study aims to evaluate the putative roles of a single acute dose of resveratrol (RVT) in preventing cerebral oxidative stress induced by bilateral common carotid artery occlusion, followed by reperfusion (BCCAO/R) and to investigate RVT’s ability to preserve the neuronal structural integrity. Frontal and temporal-occipital cortices were examined in two groups of adult Wistar rats, sham-operated and submitted to BCCAO/R. In both groups, 6 h before surgery, half the rats were gavage-fed with a single dose of RVT (40 mg/per rat in 300 µL of sunflower oil as the vehicle), while the second half received the vehicle alone. In the frontal cortex, RVT pre-treatment prevented the BCCAO/R-induced increase of lipoperoxides, augmented concentrations of palmitoylethanolamide and docosahexaenoic acid, increased relative levels of the cannabinoid receptors type 1 (CB1) and 2 (CB2), and peroxisome-proliferator-activated-receptor (PPAR)-α proteins. Increased expression of CB1/CB2 receptors mirrored that of synaptophysin and post-synaptic density-95 protein. No BCCAO/R-induced changes occurred in the temporal-occipital cortex. Collectively, our results demonstrate that, in the frontal cortex, RVT pre-treatment prevents the BCCAO/R-induced oxidative stress and modulates the endocannabinoid and PPAR-α systems. The increased expression of synaptic structural proteins further suggests the possible efficacy of RVT as a dietary supplement to preserve the nervous tissue metabolism and control the physiological response to the hypoperfusion/reperfusion challenge.

Cerebral microvascular dysfunction in metabolic syndrome is exacerbated by ischemia-reperfusion injury

Background

Metabolic syndrome (MetS) is associated with an increased risk of cerebrovascular diseases, including cerebral ischemia. Microvascular dysfunction is an important feature underlying the pathophysiology of cerebrovascular diseases. In this study, we aimed to investigate the impacts of ischemia and reperfusion (IR) injury on the cerebral microvascular function of rats with high-fat diet-induced MetS.

Results

We examined Wistar rats fed a high-fat diet (HFD) or normal diet (CTL) for 20 weeks underwent 30 min of bilateral carotid artery occlusion followed by 1 h of reperfusion (IR) or sham surgery. Microvascular blood flow was evaluated on the parietal cortex surface through a cranial window by laser speckle contrast imaging, functional capillary density, endothelial function and endothelial–leukocyte interactions by intravital videomicroscopy. Lipid peroxidation was assessed by TBARs analysis, the expression of oxidative enzymes and inflammatory markers in the brain tissue was analyzed by real-time PCR. The cerebral IR in MetS animals induced a functional capillary rarefaction (HFD IR 117 ± 17 vs. CTL IR 224 ± 35 capillary/mm²; p < 0.05), blunted the endothelial response to acetylcholine (HFD IR −16.93% vs. CTL IR 16.19% from baseline inner diameter p < 0.05) and increased the endothelial–leukocyte interactions in the venules in the brain. The impact of ischemia on the cerebral microvascular blood flow was worsened in MetS animals, with a marked reduction of cerebral blood flow, exposing brain tissue to a higher state of hypoxia.

Conclusions

Our results demonstrate that during ischemia and reperfusion, animals with MetS are more susceptible to alterations in the cerebral microcirculation involving endothelial dysfunction and oxidative stress events.

Involvement of the endocannabinoid system in the physiological response to transient common carotid artery occlusion and reperfusion

Background

The transient global cerebral hypoperfusion/reperfusion achieved by induction of Bilateral Common Carotid Artery Occlusion followed by Reperfusion (BCCAO/R) may trigger a physiological response in an attempt to preserve tissue and function integrity. There are several candidate molecules among which the endocannabinoid system (ECS) and/or peroxisome-proliferator activated receptor-alpha (PPAR-alpha) may play a role in modulating oxidative stress and inflammation. The aims of the present study are to evaluate whether the ECS, the enzyme cyclooxygenase-2 (COX-2) and PPAR-alpha are involved during BCCAO/R in rat brain, and to identify possible markers of the ongoing BCCAO/R-induced challenge in plasma.

Methods

Adult Wistar rats underwent BCCAO/R with 30 min hypoperfusion followed by 60 min reperfusion. The frontal and temporal-occipital cortices and plasma were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS) to determine concentrations of endocannabinoids (eCBs) and related molecules behaving as ligands of PPAR-alpha, and of oxidative-stress markers such as lipoperoxides, while Western Blot and immunohistochemistry were used to study protein expression of cannabinoid receptors, COX-2 and PPAR-alpha. Unpaired Student’s t-test was used to evaluate statistical differences between groups.

Results

The acute BCCAO/R procedure is followed by increased brain tissue levels of the eCBs 2-arachidonoylglycerol and anandamide, palmitoylethanolamide, an avid ligand of PPAR-alpha, lipoperoxides, type 1 (CB1) and type 2 (CB2) cannabinoid receptors, and COX-2, and decreased brain tissue concentrations of docosahexaenoic acid (DHA), one of the major targets of lipid peroxidation. In plasma, increased levels of anandamide and lipoperoxides were observed.

Conclusions

The BCCAO/R stimulated early molecular changes that can be easily traced in brain tissue and plasma, and that are indicative of the tissue physiological response to the reperfusion-induced oxidative stress and inflammation. The observed variations suggest that the positive modulation of the ECS and the increase of proinflammatory substances are directly correlated events. Increase of plasmatic levels of anandamide and lipoperoxides further suggests that dysregulation of these molecules may be taken as an indicator of an ongoing hypoperfusion/reperfusion challenge.

Neuroprotective Effect of VEGF-Mimetic Peptide QK in Experimental Brain Ischemia Induced in Rat by Middle Cerebral Artery Occlusion

We investigated the effect of the VEGF-mimetic peptide, QK, on ischemic brain damage and on blood-brain barrier permeability in the rat. QK administered by the intracerebroventricular, intravenous, or intranasal route caused a 40% decrease in ischemic brain damage induced by permanent occlusion of the middle cerebral artery relative to that in controls. No increase in the volume of the ischemic hemisphere compared to that of the contralateral nonischemic hemisphere was observed in rats treated with QK, suggesting that this peptide did not cause brain edema. The effect of QK on vessel permeability was evaluated by intravital pial microvessel videoimaging, a technique that allows the pial vessels to be visualized through a surgically prepared open cranial window. The results showed that QK did not cause any leakage of intravenously injected fluorescein-dextran conjugates after intracarotid administration or topical application to the brain cortex. Collectively, these data suggest that QK may exert neuroprotective activity in the context of stroke without promoting any increase in vascular permeability. Because VEGF's neuroprotective activity may be overshadowed by the appearance of brain edema and microbleeds, QK could represent a significant step forward in stroke treatment.

Cerebroprotective potential of resveratrol through anti-oxidant and anti-inflammatory mechanisms in rats

Oxidative stress and inflammation are two important pathological mechanisms involved in cerebral ischemia and reperfusion injury. In pathological conditions such as cerebral infarction, the free radical production is greater than that of elimination by endogenous anti-oxidant system, by this undesirable effect brain is highly injured. Resveratrol is reported to have anti-oxidant and anti-inflammatory, athero-protective activities. Therefore, the aim of the present study is to evaluate the therapeutic potential of resveratrol against cerebral infarction induced by ischemia and reperfusion injury in Wistar rats. Bi-common carotid occlusion followed by 4 h reperfusion model was used to induce cerebral infarction. Percent infarction, oxidative stress markers (malondialdehyde, catalase, superoxide dismutase) and inflammatory markers (myeloperoxidase, TNF-α, IL-6, ICAM-1 and IL-10) were measured. TNF-α, IL-6, IL-10, and intracellular adhesive molecule-I (ICAM-1) levels were quantified by enzyme-linked immunosorbent assay (ELISA). Resveratrol produced significant dose-dependent reduction in percent cerebral infarct volume. At resveratrol 20 mg/kg dose, there was a significant reduction in oxidative stress and inflammatory markers like malondialdehyde, TNF-α, IL-6, myeloperoxidase and ICAM-I and in contrast there was a significant increase in anti-oxidants and anti-inflammatory markers like superoxide dismutase, catalase and IL-10 levels. Resveratrol showed significant cerebroprotective action mediated by anti-oxidant and anti-inflammatory mechanisms.