RESUMEN
This study is to investigate the effect of hydroxyethylpuerarin on the expression of tumor necrosis factor-alpha (TNF-α) and activity of nuclear factor kappa B (NF-κB) after middle cerebral artery occlusion (MCAO) in rats. Rats were subjected to cerebral ischemia-reperfusion injury induced by MCAO. Hydroxyethylpuerarin (10, 20, 40 mg·kg-1, iv) was administered just 30 min before occlusion and immediately after reperfusion. After a 24 h reperfusion following 2 h of MCAO, the number of viable neurons in hippocampal CA1 region was counted by hematoxylin and eosin (HE) staining. TNF-α protein and its mRNA expression were examined with radioimmunoassay (RIA) and reverse transcriptase-polymerase chain reaction (RT-PCR) respectively. NF-κB activity was observed by electrophoretic mobility shift assay (EMSA), and inhibition of NF-κB α (IκBα) protein expression was evaluated by Western blotting analysis. Animals treated with hydroxyethylpuerarin had a significant increase in neuronal survival in comparison with vehicle-treated group. Hydroxyethylpuerarin significantly reduced the protein and mRNA expression of TNF-α following 2 h of ischemia with 24 h of reperfusion. NF-κB DNA binding activity and the degradation of IκBα in the cytoplasm also decreased by hydroxyethylpuerarin treatment. The protective effects of hydroxyethylpuerarin against ischemia-reperfusion injury may be mediated by decreasing the expression of TNF-α and the activity of NF-κB in rats.
RESUMEN
Aim To observe the damages induced by hydrogen peroxide in cultured bovine cerebral microvascular endothelial cells (BCMEC) and evaluate the protective effects of hydroxyethylpuerarin on hydrogen peroxide-injured BCMEC. Methods BCMEC were cultured and transferred into modified Eagle medium (MEM). The viability of cells was detected by MTT assay. Cell injury was determined by lactate dehydrogenase (LDH) activity in the extracellular medium. Flow cytometry was employed to observe the occurrence of apoptosis. Morphologic changes of cells were visualized under phase contrast and electron occurrence of apoptosis. Hydroxyethylpuerarin was shown to increase the survival rate and decrease the activity of LDH of BCMEC damaged by hydrogen peroxide. Hydroxyethylpuerarin was also found to protect BCMEC against apoptosis induced by hydrogen peroxide. Conclusion Hydrogen peroxide induces BCMEC injury either by apoptosis or through necrosis. Hydroxyethylpuerarin protects BCMEC against hydrogen peroxide-induced injury in a concentration-dependent manner. Its antioxidant effects might be involved as the mechanism protection.