PI3K/Akt pathway contributes to neuroprotective effect of Tongxinluo against focal cerebral ischemia and reperfusion injury in rats.
Tongxinluo (TXL), a compound prescription, is formulated according to the collateral disease doctrine of traditional Chinese medicine, and is widely used for the treatment of cardio-cerebrovascular diseases in China.
We aimed to investigate the neuroprotective effect of TXL on focal cerebral ischemia and reperfusion injury in rats by attenuating its brain damage and neuronal apoptosis, and to assess the potential role of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in this protection.
Adult Male Sprague-Dawley rats (n=120) were randomly divided into 5 groups: sham, cerebral ischemia and reperfusion (I/R), cerebral ischemia and reperfusion plus TXL (1.6g/kg/day) (TXL1.6), TXL1.6 plus LY294002 and dimethyl sulfoxide (DMSO) (TXL1.6+LY294002), TXL1.6 plus DMSO (TXL1.6+vehicle). Prior to the grouping, TXL1.6 was selected to be the optimal dose of TXL by evaluating the neurological deficits score of five group rats (Sham, I/R, TXL0.4, TXL0.8 and TXL1.6, n=30) at 0, 1, 3, 5, and 7 days after reperfusion. Rats, being subjected to middle cerebral artery occlusion (MCAO) for 90min followed by 24h reperfusion, were the cerebral ischemia/reperfusion models. At 24h after reperfusion, cerebral infarct area was measured via tetrazolium staining and neuronal damage was showed by Nissl staining. The double staining of Terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end labeling (TUNEL) staining and immunofluorescence labeling with NeuN, was performed to evaluate neuronal apoptosis. Proteins involved in PI3K/Akt pathway were detected by Western blot.
The results showed that TXL markedly improved neurological function, reduced cerebral infarct area, decreased neuronal damage, and significantly attenuated neuronal apoptosis, while these effects were eliminated by inhibition of PI3K/Akt with LY294002. We also found that TXL up-regulated the expression levels of p-PDK1, p-Akt, p-c-Raf, p-BAD and down-regulated Cleaved caspase 3 expression notably, which were partially reversed by LY294002. Additionally, the increment of p-PTEN level on which LY294002 had little effect was also detected in response to TXL treatment.
These findings demonstrated that TXL provided neuroprotection against cerebral ischemia/reperfusion injury and neuronal apoptosis, and this effect was mediated partly by activation of the PI3K/Akt pathway.
Yu ZH
，Cai M
，Xiang J
，Zhang ZN
，Zhang JS
，Song XL
，Zhang W
，Bao J
，Li WW
，Cai DF
... -
《-》
Cerebroprotective effect of Eclipta alba against global model of cerebral ischemia induced oxidative stress in rats.
Oxidative stress is believed to contribute to neuronal damage induced by cerebral ischemia/reperfusion (I/R) injury. The present study was undertaken to evaluate the possible cerebroprotective and antioxidant effect of hydroalcoholic extract of Eclipta alba against global cerebral ischemia in the rat. Adult Wistar albino rats were treated with extract of Eclipta alba (250 and 500mg/kg/day, p.o.) for 10 days. The global cerebral ischemia-reperfusion injury was induced by occluding bilateral common carotid arteries (BCCA) for 30min, followed by 4h reperfusion. Quercetin (20mg/kg, i.p.) was used for the reference compound. After that, animals were sacrificed by decapitation, brain was removed, various biochemical estimations, cerebral edema, assessment of cerebral infarct size, and histopathological examinations were carried out. BCCA caused significant depletion in superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH), catalase (CAT), glutahione-S-transferase (GST), glutathione ruductase (GR) and significant increase in malondialdehyde (MDA) in brain. Pretreatment with hydroalcoholic extract of Eclipta alba significantly reversed the levels of biochemical parameters and significantly reduced the edema and cerebral infarct size as compared to the ischemic control group. Eclipta alba at higher dose markedly reduced ischemia-induced neuronal loss of the brain. Reduction of cerebral edema, an early symptom of ischemia, is one of the most important remedies for reducing subsequent chronic neural damage in stroke. The results of the study show that Eclipta alba pretreatment ameliorates cerebral ischemia/reperfusion injury and enhances the antioxidant defense against BCCA occlusion induced I/R in rats; so it exhibits cerebroprotective property. HPLC fingerprint of hydroalcoholic extract of Eclipta alba was performed for conforming the coumestan present in the plant extract.
Mansoorali KP
，Prakash T
，Kotresha D
，Prabhu K
，Rama Rao N
... -
《-》
The effect of mitochondrial calcium uniporter opener spermine on diazoxide against focal cerebral ischemia--reperfusion injury in rats.
Recent research has indicated that mitochondrial adenosine triphosphate-sensitive potassium channels play an important role in cerebral protection, which involves in attenuating the calcium of mitochondria. However, the effect of diazoxide on cerebral ischemia-reperfusion and the role of spermine, the agonist of mitochondrial calcium uniporter (MCU), remain unknown.
We investigated the effect of MCU opener spermine on diazoxide against focal cerebral ischemia-reperfusion injury in rats.
Adult male Wistar rats were randomly divided into 5 groups: the Sham group, the I/R group, the Dzx + I/R group, the Dzx + Sper + I/R group, and the Sper + I/R group. Rats were exposed to 2-hour ischemia and 24-hour reperfusion. Diazoxide were administrated 30 minutes before ischemia, and spermine were given 10 minutes before reperfusion. Rats in the Sham group did not experience the process of ischemia-reperfusion. After 24-hour reperfusion, rats were given neurological performance tests, overdosed with general anesthesia, and then their brains were excised for infarct volume, pathological changes, and biochemical evaluation and analysis.
Rats in the Dzx + I/R group displayed improved neurological deficits and decreased infarct volume and oxidative stress (evidenced by decreased nitric oxide and malondialdehyde but increased antioxidant enzymes [eg, glutathione peroxide and superoxide dismutase]) caused by ischemia-reperfusion. The beneficial effects of diazoxide were significantly attenuated by spermine treatment. Rats in the Sper + I/R group displayed worse neurological deficits, larger infarct volume and more oxidative stress, and less antioxidant enzymes than those in the Dzx + I/R.
Our results suggested that diazoxide, which improved neurological deficits and decreased infarct volume and oxidative stress against ischemia-reperfusion injury, is mediated by spermine.
Dong H
，Wang S
，Zhang Z
，Yu A
，Liu Z
... -
《-》
ResearchGate
(全网免费下载)
钛学术
(全网免费下载)
