Baicalein is neuroprotective in rat MCAO model: role of 12/15-lipoxygenase, mitogen-activated protein kinase and cytosolic phospholipase A2.

Inflammatory damage and oxidative stress play an important role in cerebral ischemic pathogenesis and may represent a target for treatment. Baicalein, isolated from the traditional Chinese herbal medicine Huangqin, is an antioxidant and anti-inflammatory agent on one hand and a lipoxygenase inhibitor on the other hand. However, little is known regarding the mechanism of baicalein's neuroprotection in ischemic stroke. We therefore investigated the potential neuroprotective effects of baicalein and explored the underlying mechanisms. Male, Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO) and baicalein was administered intravenously immediately after cerebral ischemia. At 24h after MCAO neurological deficit, brain water content and infarct sizes were measured. Immunohistochemistry, western blot and reverse transcription-polymerase chain reaction (RT-PCR) were used to analyse the expression of 12/15-lipoxygenase (12/15-LOX), p38 mitogen-activated protein kinase (p38 MAPK) and cytosolic phospholipase A2 (cPLA2) at gene and protein levels in ischemic brain cortex. The results showed that baicalein improved neurological deficit, reduced brain water content and infarct sizes, and downregulated the overexpression of 12/15-LOX, p38 MAPK and cPLA2 typically seen with MCAO. The results indicated that baicalein protected the brain from damage caused by MCAO, and this effect may be through downregulation of 12/15-LOX, p38 MAPK and cPLA2 expression.

Cui L ，Zhang X ，Yang R ，Liu L ，Wang L ，Li M ，Du W ... -  《-》

Neuroprotection of early and short-time applying atorvastatin in the acute phase of cerebral ischemia: down-regulated 12/15-LOX, p38MAPK and cPLA2 expression, ameliorated BBB permeability.

It has been proved that chronic administration and pre-treatment with atorvastatin could protect brain tissue against ischemic injury. However, little is known regarding the effect of atorvastatin in the acute phase of ischemic stroke. This study investigated the potential neuroprotective effects of atorvastatin and underlying mechanisms in vivo. Male Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO). Experiment 1 was used to evaluate time course expressions of 12/15-LOX, mitogen-activated protein kinase (MAPK), phosphorylated-p38MAPK (phospho-p38MAPK) and cytosolic phospholipase A2 (cPLA2) after cerebral ischemia, seven time points were included. Experiment 2 was used to detect atorvastatin's neuroprotection in the acute phase of ischemic stroke; atorvastatin was administered immediately after MCAO. Neurological deficit, brain water content and infarct size were measured at 24h after stoke. Immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to analyze the expression of 12/15-LOX, p38MAPK, phospho-p38MAPK and cPLA2. Experiment 3 was used to detect atorvastatin's influence on blood-brain barrier (BBB). 12/15-LOX, p38MAPK, phospho-p38MAPK and cPLA2 were up-regulated after cerebral ischemia. Compared with MCAO group, atorvastatin dramatically reduced brain water content and infarct sizes, and the over-expressions of 12/15-LOX, p38MAPK, phospho-p38MAPK and cPLA2 were significantly decreased in high dose group (20mg/kg, P<0.05). Meanwhile, extra-vascular IgG was not only reduced, but BBB permeability was also ameliorated. Atorvastatin protected brain from damage caused by MCAO at the early stage; this effect may be through down-regulation of 12/15-LOX, p38MAPK and cPLA2 expressions, and ameliorating BBB permeability.

Cui L ，Zhang X ，Yang R ，Wang L ，Liu L ，Li M ，Du W ... -  《-》

Neuroprotection and underlying mechanisms of oxymatrine in cerebral ischemia of rats.

Cui L ，Zhang X ，Yang R ，Wang L ，Liu L ，Li M ，Du W ... -  《-》

Neuroprotection of taurine through inhibition of 12/15 lipoxygenase pathway in cerebral ischemia of rats.

Zhang Z ，Yu R ，Cao L 《-》

Luteolin downregulates TLR4, TLR5, NF-κB and p-p38MAPK expression, upregulates the p-ERK expression, and protects rat brains against focal ischemia.

Inflammatory damage is known to be involved in ischemic stroke. Luteolin has been proved to elicit a series of biologic effects through its anti-inflammatory property in multiple sclerosis and rheumatoid arthritis. Whether this protective effect applies to ischemic injury in brain is still unknown, we therefore investigate the potential neuroprotective role of luteolin in ischemic stroke and the underlying mechanisms. Male Sprague-Dawley rats were subjected to pMCAO and luteolin was administered intraperitoneally immediately after surgery, then once daily thereafter. Neurological deficit, infarct volume, and brain water content were measured at 24 h and 72 h after stroke. The expression of TLR4, TLR5, and NF-κB were measured by real-time PCR, immunohistochemical staining (IHC), and Western blot. P38MAPK and extracellular signal-regulated kinase (ERK) were detected by IHC, and Western blot. Compared with pMCAO group, luteolin significantly alleviated neurological deficit, decreased infarct volume and suppressed edema after ischemic stroke, which were accompanied with decreased expression of TLR4, TLR5, NF-κB and p-p38MAPK. Meanwhile, luteolin activated the expression of p-ERK1/2 (P<0.05). Luteolin protected the brain from the damage caused by pMCAO, and this effect may be through downregulation of TLR4, TLR5, NF-κB, p38MAPK and upregulation of ERK expression.

Qiao H ，Zhang X ，Zhu C ，Dong L ，Wang L ，Zhang X ，Xing Y ，Wang C ，Ji Y ，Cao X ... -  《-》