黄芩苷锌对改善缺血性视神经损伤中氧化应激反应及激活血源性因子修复血神经屏障的作用和机制

目的:探讨黄芩苷锌(HBZn)改善缺血性视神经损伤模型中氧化应激损伤及修复血神经屏障(BNB)的作用及机制。方法:单侧夹闭颈总动脉法建立小鼠视神经损伤模型,随机分为缺血损伤组、假手术组、黄芩苷锌组(3.75,6.5,13 mg·kg-1),黄芩苷组及葡萄糖酸锌(zinc gluconate)组。超微电镜观察视神经细胞线粒体的结构;比色法检测缺血损伤2 h后各组小鼠血浆中超氧化物歧化酶(SOD),丙二醛(MDA),髓过氧化物酶(MPO)的变化。RNA实时荧光定量PCR检测基质金属蛋白酶(MMPs)/基质金属蛋白酶组织抑制因子(TIMPs)的mRNA表达;蛋白免疫印迹法(Western blot)测定视神经组织中免疫球蛋白G(Ig G)(缺血后12 h),纤维蛋白原(Fibrinogen,缺血后28 h),MMP-9(缺血后2 d)蛋白表达水平。结果:黄芩苷锌(6.5 mg·kg-1)组能保护缺血导致的线粒体损伤,增强机体的抗氧化应激能力,激活SOD活性,降低MDA,MPO水平。能修复血神经屏障,Ig G,Fibrinogen,MMP-9等血源性因子蛋白表达量增加,调节MMPs/TIMPs的平衡。结论:黄芩苷对缺血性视神经损伤有保护作用,作用明显优于单独用药的等摩尔浓度HB组和等摩尔浓度锌的葡萄糖酸锌组,其作用机制可能与保护线粒体,抑制小鼠视神经组织中血源性因子Ig G,Fibrinogen,MMP-9的激活,抑制MMPs家族的表达,调节MMPs/TIMPs的平衡和异常沉积来修复血神经屏障有关,同时证明黄芩苷和锌的络合物增强了单体抗氧化应激和缺血性损伤的能力。

Effect of HBZn in Repairing BNB in Mice by Alleviating Anti-oxidative Stress and Activating Hematogenous Factors in Optic Nerve Injury

Objective: To explore the effect of baicalin zinc (HBZn) in repairing BNB in mice by alleviating anti-oxidative stress and activating hematogenous factors in optic nerve injury. Method: A model of optic nerve injury in mice was established by unilateral interlocking carotid artery, and the mice were divided into 7 groups, namely ischemia group, sham operated group, HBZn group (3.75, 6.5, 13 mg·kg^-1), HB group, and zinc gluconate group. Each group was administered by gavage for 5 days before operation. Optic nerve crush injury was made on every group, except for sham group. Mitochondrias were observed under electron microscope; superoxide dismutase (SOD), malondialdehyde (MDA), and myeloperoxidase (MPO) of plasma were measured by colorimetric. The expressions of immunoglobulin G(IgG), Fibriogen and matrix metallo protein9(MMP-9) were detected by Western blot. MMPs/TIMPs were detected by qPCR. Result: HBZn can effectively prevent the injury of mitochondria, reduce the concentrations of MDA and MPO, increase the concentration of SOD, compared with HB group and znic gluconate group (P < 0.05). HBZn can reduce the expressions of IgG, Fibriogen and MMP-9 more effectively than ischemia group, suppress the expression of the MMPs family and adjust the balance of MMPs/TIMPs. Conclusion: HBZn can protect the optic nerve injury in mice, and its mechanism may be correlated with the ability to resist oxidative stress and the activating MMP-9, IgG and Fibriogen. HBZn has better anti-oxidative and repairing abilities than monomer baicalin and trace element zinc.