Connexin 43 mediated the angiogenesis of buyang huanwu decoction via vascular endothelial growth factor and angiopoietin-1 after ischemic stroke.

Buyang Huanwu decoction (BYHWD), a classical prescription for ischemic stroke, has been reported to promote angiogenesis after focal ischemia. However, the mechanisms of the contribution of BYHWD on angiogenesis are still unclear. Connexin 43 (Cx43) played important roles in the functions of neurogliovascular unit. Therefore, the aim of this study was to explore the potential role of Cx43 in angiogenesis of the ischemic brain after BYHWD treatment. Middle cerebral artery occlusion (MCAO) was used to establish the model of focal ischemia. BYHWD was administrated intragastrically twice a day after MCAO with or without Gap26 (a specific Cx43 inhibitor). Western blot, neurological deficits, immunofluorescent staining, and Evans blue dye were used to confirm the role of Cx43 in angiogenesis after BYHWD treatment. The expression levels of total Cx43 and phosphorylated Cx43 were upregulated by BYHWD and peaked at 7 days post MCAO. Inhibition of Cx43 with Gap26 significantly attenuated the protective role of BYHWD in neurological behavior. BYHWD treatment promoted angiogenesis demonstrated by increased microvascular density, upregulated vascular endothelial growth factor (VEGF), and angiopoietin-1 (Ang-1), while inhibition of Cx43 with Gap26 attenuated these effects of BYHWD. In addition, Gap26 inhibited the beneficial effect of BYHWD on blood-brain barrier (BBB) integrity. These results suggested that Cx43 mediated the angiogenesis of BYHWD via VEGF and Ang-1 after focal ischemic stroke.

Protective Effect of Capparis spinosa Extract against Focal Cerebral Ischemia-reperfusion Injury in Rats.

BACKGROUND: Ischemic stroke is a serious public health problem. Despite extensive researches focusing on the area, little is known about novel treatments. OBJECTIVE: In this study, we aimed to investigate the effects of Capparis spinosa (C. spinosa) extract in the middle cerebral artery occlusion (MCAO) model of ischemic stroke. METHODS: Wistar rats underwent 30-min MCAO-induced brain ischemia followed by 24 h of reperfusion. C. spinose was administrated orally once a day for 7 days before the induction of MCAO. The neurologic outcome, infarct volume (TTC staining), histological examination, and markers of oxidative stress, including total thiol content, and malondialdehyde (MDA) levels, were measured 24hr. after the termination of MCAO. RESULTS: Pretreatment with C. spinosa reduced neurological deficit score, histopathological alterations, and infarct volume in treated groups compared to the stroke group. Furthermore, pretreatment with C. spinosa extract significantly reduced the level of MDA with concomitant increases in the levels of thiol in the brain tissues compared to the stroke group. CONCLUSION: Our study demonstrates that C. spinosa extract effectively protects MCAO injury through the attenuation or the suppression of the oxidative stress.

Promising Anti-stroke Signature of Voglibose: Investigation through In- Silico Molecular Docking and Virtual Screening in In-Vivo Animal Studies.

BACKGROUND: Postprandial hyperglycemia considered to be a major risk factor for cerebrovascular complications. OBJECTIVE: The current study was designed to elucidate the beneficial role of voglibose via in-silico in vitro to in-vivo studies in improving the postprandial glycaemic state by protection against strokeprone type 2 diabetes. MATERIALS AND METHODS: In-Silico molecular docking and virtual screening were carried out with the help of iGEMDOCK+ Pymol+docking software and Protein Drug Bank database (PDB). Based on the results of docking studies, in-vivo investigation was carried out for possible neuroprotective action. T2DM was induced by a single injection of streptozotocin (90mg/kg, i.v.) to neonates. Six weeks after induction, voglibose was administered at the dose of 10mg/kg p.o. for two weeks. After eight weeks, diabetic rats were subjected to middle cerebral artery occlusion, and after 72 hours of surgery, neurological deficits were determined. The blood was collected for the determination of serum glucose, CK-MB, LDH and lipid levels. Brains were excised for determination of brain infarct volume, brain hemisphere weight difference, Na+-K+ ATPase activity, ROS parameters, NO levels, and aldose reductase activity. RESULTS: In-silico docking studies showed good docking binding score for stroke associated proteins, which possibly hypotheses neuroprotective action of voglibose in stroke. In the present in-vivo study, pre-treatment with voglibose showed a significant decrease (p<0.05) in serum glucose and lipid levels. Voglibose has shown significant (p<0.05) reduction in neurological score, brain infarct volume, the difference in brain hemisphere weight. On biochemical evaluation, treatment with voglibose produced significant (p<0.05) decrease in CK-MB, LDH, and NO levels in blood and reduction in Na+-K+ ATPase, oxidative stress, and aldose reductase activity in brain homogenate. CONCLUSION: In-silico molecular docking and virtual screening studies and in-vivo studies in MCAo induced stroke, animal model outcomes support the strong anti-stroke signature for possible neuroprotective therapeutics.

Yonkenafil: a novel phosphodiesterase type 5 inhibitor induces neuronal network potentiation by a cGMP-dependent Nogo-R axis in acute experimental stroke.

Yonkenafil is a novel phosphodiesterase type 5 (PDE5) inhibitor. Here we evaluated the effect of yonkenafil on ischemic injury and its possible mechanism of action. Male Sprague-Dawley rats underwent middle cerebral artery occlusion, followed by intraperitoneal or intravenous treatment with yonkenafil starting 2h later. Behavioral tests were carried out on day 1 or day 7 after reperfusion. Nissl staining, Fluoro-Jade B staining and electron microscopy studies were carried out 24h post-stroke, together with an analysis of infarct volume and severity of edema. Levels of cGMP-dependent Nogo-66 receptor (Nogo-R) pathway components, hsp70, apaf-1, caspase-3, caspase-9, synaptophysin, PSD-95/neuronal nitric oxide synthases (nNOS), brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) and nerve growth factor (NGF)/tropomyosin-related kinase A (TrkA) were also measured after 24h. Yonkenafil markedly inhibited infarction and edema, even when administration was delayed until 4h after stroke onset. This protection was associated with an improvement in neurological function and was sustained for 7d. Yonkenafil enlarged the range of penumbra, reduced ischemic cell apoptosis and the loss of neurons, and modulated the expression of proteins in the Nogo-R pathway. Moreover, yonkenafil protected the structure of synapses and increased the expression of synaptophysin, BDNF/TrkB and NGF/TrkA. In conclusion, yonkenafil protects neuronal networks from injury after stroke.

Achyrocline satureioides (Lam.) DC. (marcela) reduces brain damage in permanent focal ischemia in rats / Achyrocline satureioides (Lam.) DC. (marcela) reduce el daño cerebral en la isquemia focal permanente en ratas

Introduction: Achyrocline satureioides is a plant which has been widely used in popular medicine and experimental studies confirm its antioxidant and anti-inflammatory effects, attributable to the presence of flavonoids, mainly quercetin. Objectives: to evaluate the neuroprotective effects of a chronic oral pre-administration to rats with an Achyrocline satureioides decoction (2 %). Methods: for decoction, dried flowers of Achyrocline satureioides were used. The consumption of food and AS decoction/water of the rats was evaluated daily and weight gain weekly; quercetin content in the decoction and in the plasma of the rats was evaluated by high performance liquid chromatography. The cerebral damage was assessed with a tetrazolium salt (TTC) and a behavioral test was performed previously. Nissl staining and Fluoro-Jade histochemistry were used. Results: the pre-treatment with Achyrocline satureioides in all groups reverted the functional deficit and, during 21 days, the infarction volume also decreased significantly. Nissl staining showed a higher percentage of preserved neuronal population and the Fluoro-Jade showed a decreased of the neurons in degeneration. Conclusions: the quercetin levels in the decoction and plasma of rats could explain the preventive benefits of Achyrocline satureioides due to the antioxidant and anti-inflammatory properties described for this flavonoid.

Introducción: Achyrocline satureioides es una planta que ha sido ampliamente utilizada en la medicina popular y los estudios experimentales confirman sus efectos antioxidantes y antiinflamatorios, atribuibles a la presencia de flavonoides, principalmente quercetina. Objetivos: evaluar los efectos neuroprotectores de la pre-administración oral crónica a ratas con una decocción de Achyrocline satureioides 2 %. Métodos: para la decocción se utilizaron flores secas de Achyrocline satureioides. Se cuantificaron, diariamente, el consumo de alimentos, la decocción y el agua; y cada semana, la ganancia de peso. El contenido de quercetina en la decocción y en el plasma de las ratas se evaluó utilizando la técnica de cromatografía líquida de alta resolución. El daño cerebral se cuantificó con una sal de tetrazolio y antes se realizó una prueba de comportamiento. Se utilizaron la tinción de Nissl y el fluoro Jade. Resultados: el pretratamiento con Achyrocline satureioides en todos los grupos revirtió el déficit funcional, y la decocción durante 21 días también decreció de modo significativo el volumen del infarto. La tinción de Nissl mostró alto porcentaje de población neuronal conservada y el fluoro Jade presentó un decrecimiento en las neuronas en degeneración. Conclusiones: los niveles de quercetina en la decocción y el plasma de las ratas podrían explicar los beneficios preventivos de Achyrocline satureioides, debido a las propiedades antioxidantes y antiinflamatorias descritas para este flavonoide.

Correlated sodium and potassium imbalances within the ischemic core in experimental stroke: a 23Na MRI and histochemical imaging study.

This study addresses the spatial relation between local Na(+) and K(+) imbalances in the ischemic core in a rat model of focal ischemic stroke. Quantitative [Na(+)] and [K(+)] brain maps were obtained by (23)Na MRI and histochemical K(+) staining, respectively, and calibrated by emission flame photometry of the micropunch brain samples. Stroke location was verified by diffusion MRI, by changes in tissue surface reflectivity and by immunohistochemistry with microtubule-associated protein 2 antibody. Na(+) and K(+) distribution within the ischemic core was inhomogeneous, with the maximum [Na(+)] increase and [K(+)] decrease typically observed in peripheral regions of the ischemic core. The pattern of the [K(+)] decrease matched the maximum rate of [Na(+)] increase ('slope'). Some residual mismatch between the sites of maximum Na(+) and K(+) imbalances was attributed to the different channels and pathways involved in transport of the two ions. A linear regression of the [Na(+)]br vs. [K(+)]br in the samples of ischemic brain indicates that for each K(+) equivalent leaving ischemic tissue, 0.8±0.1 Eq, on average, of Na(+) enter the tissue. Better understanding of the mechanistic link between the Na(+) influx and K(+) egress would validate the (23)Na MRI slope as a candidate biomarker and a complementary tool for assessing ischemic damage and treatment planning.

Optimal electroacupuncture frequency for maintaining astrocyte structural integrity in cerebral ischemia.

The astrocyte is a critical regulator of neuronal survival after ischemic brain injury. Electroacupuncture may be an effective therapy for cerebral ischemia, as electroacupuncture frequency can affect the structural integrity of astrocytes. In this study, a rat model of middle cerebral artery occlusion established using the modified thread embolism method was treated with electroacupuncture of the bilateral Quchi (LI11) and Zusanli (ST36) at 15, 30, and 100 Hz frequencies. Behavioral testing, immunohistochemistry and electron microscopy were used to explore the effect of these electroacupuncture frequencies used on maintaining the structural integrity of ischemic brain tissue. Compared with the model and 100 Hz electroacupuncture groups, the 15 and 30 Hz electroacupuncture groups displayed decreased neurological deficit scores, as evaluated by the "Longa" method, significantly increased glial fibrillary acidic protein expression, and alleviated ultrastructural damage of astrocytes at the edge of the infarct. Our experimental findings indicate that 15 and 30 Hz electroacupuncture intervention can favorably maintain the structural integrity of astrocytes and play a protective role in cerebral ischemic injury. Astrocyte structural integrity may be the mechanism underlying acupuncture production of ischemic tolerance.