凌霄花总黄酮对脑缺血再灌注损伤大鼠NF-κB/iNOS-COX-2信号通路的影响

Effects of total flavone of Campsis grandiflora(Thunb.) K. Schum. on signal pathway NF-κB/i NOS-COX-2 in cerebral ischemia-reperfusion injury rats

目的:研究凌霄花总黄酮对脑缺血再灌注损伤大鼠脑组织中NF-κB/i NOS-COX-2信号通路的影响,并探讨其可能机制。方法:60只SPF级Wistar雄性大鼠随机分为假手术组,模型组,阿司匹林片组(50mg/kg),凌霄花总黄酮高、低剂量组(200、100mg/kg)。建立短暂性大脑中动脉阻塞大鼠模型(t MCAO),分光光度法检测脑匀浆中i NOS活力和NO水平;免疫组化染色法评价脑组织中NF-κB p65和COX-2阳性表达情况。结果:与假手术组比较,模型组大鼠脑匀浆中i NOS活力和NO水平明显升高(P<0.01);NF-κB p65、COX-2阳性表达细胞数明显增多,发生核移位的NF-κB p65阳性细胞数也明显增多(P<0.01);与模型组比较,凌霄花总黄酮高、低剂量组和阿司匹林组均能明显降低脑匀浆中i NOS活力和NO水平(P<0.01),明显减少NF-κB p65、COX-2阳性表达细胞数和发生核移位的NF-κB p65阳性细胞数(P<0.01);与阿司匹林组比较,凌霄花总黄酮高剂量组能明显降低NF-κB p65、COX-2阳性表达细胞数目,并抑制NF-κB p65蛋白的核移位(P<0.01,P<0.05)。结论:凌霄花总黄酮能抑制脑缺血再灌注损伤的炎性反应,可能与抑制NF-κB/i NOS-COX-2信号通路的激活有关。

Objective: To study the effects of total flavone of Campsis grandiflora(Thunb.) K. Schum.(Lingxiaohua) on signal pathway NF-κB/i NOS-COX-2 in cerebral ischemia-reperfusion injury rats, and to explore the possible mechanism. Methods: Sixty Wistar male rats in grade SPF were randomly divided into a sham operation group, a model group, an Aspirin group(50mg/kg), and a high and low dose of total flavone of Lingxiaohua group(200, 100mg/kg, respectively). Transient middle cerebral artery occlusion(t MCAO) rat model was established, and the activity of i NOS and level of NO in brain homogenate were detected by spectrophotometry. The positive expression of NF-κB and COX-2 in brain tissues was detected by immunohistochemical staining. Results: Compared with the sham operation group, the levels of i NOS and NO in the model group were significantly increased(P<0.01), and the numbers of positive cells of NF-κB p65 and COX-2 were obviously increased, as well as the nuclear translocation positive cells of NF-κB p65(P<0.01); Compared with the model group, the levels of i NOS and NO in the Aspirin group, high and low dose of total flavone of Lingxiaohua group were significantly decreased(P<0.01), and the numbers of positive cells of NF-κB p65 and COX-2 were obviously declined, as well as the nuclear translocation positive cells of NF-κB p65(P<0.01); Compared with the Aspirin group, the numbers of positive cells of NF-κB p65 and COX-2 in the high dose of total flavone of Lingxiaohua group were obviously declined, as well as the nuclear translocation positive cells of NF-κB p65(P<0.01, P<0.05). Conclusion: The total flavone of Lingxiaohua could inhibit the inflammation induced by cerebral ischemia reperfusion injury, which might be related with inhibiting the activation of NF-κB/i NOS-COX-2 signaling pathway.