Inhibition of sonic hedgehog signaling aggravates brain damage associated with the down-regulation of Gli1, Ptch1 and SOD1 expression in acute ischemic stroke

Flutamide Enhances Neuroprotective Effects of Testosterone during Experimental Cerebral Ischemia in Male Rats

Testosterone has been shown to worsen histological and neurological impairment during cerebral ischemia in animal models. Cell culture studies revealed that testosterone is implicated in protecting neural and glial cells against insults, and they started to elucidate testosterone pathways that underlie these protective effects. These studies support the hypothesis that testosterone can be neuroprotective throughout an episode of cerebral ischemia. Therefore, we evaluated the mechanisms underlying the shift between testosterone protective and deleterious effects via block testosterone aromatization and androgen receptors in rats subjected to 60-minute middle cerebral artery occlusion. Fifty rats were divided into five equal groups: gonadally intact male; castrated male; intact male + flutamide; intact male + letrozole; intact male + combination flutamide and letrozole. Our results indicated that castration has the ability to reduce histological damage and to improve neurological score 24 hours after middle cerebral artery occlusion. Moreover, flutamide improved histologic and neurological impairment better than castration. Letrozole induced increases in striatal infarct volume and seizures in gonadally intact rats. Combination of flutamide and letrozole showed that letrozole can reverse beneficial effects of flutamide. In conclusion, it seems that the beneficial effects of flutamide are the prevention of the deleterious effects and enhancement of neuroprotective effects of testosterone during cerebral ischemia.

Neuroprotective effect of early and short-time applying sophoridine in pMCAO rat brain: down-regulated TRAF6 and up-regulated p-ERK1/2 expression, ameliorated brain infaction and edema

BACKGROUND

Matrine has been proven to protect ischemic injury in brain and sophoridine (SOP) is an isomeride of matrine. It is unknown whether SOP has this protective effect on ischemic injury in brain. We therefore investigated the potential neuroprotective role of SOP and the underlying mechanism.

METHODS

Male, Sprague-Dawley rats were randomly assigned into five groups: Vehicle (pMCAO+saline), High dose (pMCAO+SOP 10 mg/kg), Middle dose (pMCAO+SOP 5 mg/kg), Low dose (pMCAO+SOP 2.5 mg/kg) and Sham operated group. Permanent middle cerebral artery occlusion (pMCAO) model was used and SOP was administered intraperitoneally immediately after cerebral ischemia and once daily in the following days. Neurological deficit was evaluated using a modified six point scale; brain water content and infarct volume were measured. The expression of TRAF6 and ERK1/2 were measured by immunohistochemistry, Western blotting.

RESULTS

Compared with Vehicle group, the cerebral edema was alleviated in High dose group (P<0.05), and the infarct volume was decreased in Low dose group (P<0.05). Consistent with these results, immunohistochemistry and Western blot analysis indicated that TRAF6 expression was significantly decreased in SOP administrated groups at 24 h, and the expression of phosphorylated ERK1/2 increased in Low dose at 72 h.

CONCLUSIONS

SOP protected the brain from damage caused by pMCAO, and this effect may be through down-regulation of TRAF6 expression and up-regulation of ERK1/2 phosphorylation expression.

Neuroprotection of early and short-time applying berberine in the acute phase of cerebral ischemia: up-regulated pAkt, pGSK and pCREB, down-regulated NF-κB expression, ameliorated BBB permeability

BACKGROUND

Berberine (BBR) has gained attention for its vast beneficial biological effects through immunomodulation, anti-inflammatory and anti-apoptosis properties. Inflammatory and apoptosis damage play an important role in cerebral ischemic pathogenesis and may represent a target for treatment. The aim of this study was to explore BBR's effect in ischemic injury and the role of the Akt/GSK (glycogen synthase kinase) signaling cascade in mediating the anti-apoptosis and anti-inflammatory effects in the rat brain of permanent middle cerebral artery occlusion (pMCAO). Male Sprague-Dawley rats were subjected to pMCAO and randomly assigned into four groups: Sham (sham-operated) group, pMCAO (pMCAO+0.9% saline) group, BBR-L (pMCAO+BBR 10 mg/kg) and BBR-H (pMCAO+BBR 40 mg/kg) group. BBR was administered immediately after pMCAO and the neuroprotection was detected. Phospho-Akt (pAkt), phospho-glycogen synthase kinase 3-β (pGSK3β), phospho-cAMP response element binding protein (pCREB), nuclear factor-kappa B (NF-κB) and claudin-5 in ischemic cerebral cortex were detected by immunohistochemistry, reverse transcription-polymerase chain reaction and western blotting. Compared with pMCAO group, BBR dramatically lessened neurological deficits scores, brain water contents and infarct sizes, upregulated the expression of pAkt, pGSK3β, pCREB and claudin-5, and decreased the nuclear accumulation of NF-κB (P<0.05) in ischemic brain. The results showed that BBR reduced ischemic brain injury after pMACO, and this effect may be via the increasing the activation of Akt/GSK signaling and claudin-5, and decreasing NF-κB expression.