重组幽门螺杆菌过氧化氢酶对结肠粘膜上皮细胞氧化应激的影响

目的 探讨重组幽门螺杆菌过氧化氢酶(rHpCAT)对大鼠结肠粘膜上皮细胞氧化应激的影响。方法 在分离培养正常大鼠结肠粘膜上皮细胞的基础上,利用FeSO₄+H₂O₂反应产生羟自由基攻击制备结肠粘膜细胞氧化损伤模型,同时预先加入rHpCAT并观察损伤减轻程度。实验设正常对照组、模型对照组、5-氨基水杨酸给药组(0.1 mmol/L)、重组幽门螺杆菌过氧化氢酶给药组(1×10⁵、1×10⁶、1×10⁷ U/kg·b.w.)。培养一定时间后,取上清测乳酸脱氢酶(LDH)、丙二醛(MDA) 和髓过氧化物酶(MPO)的活性进行测定,并同时测定上述各组谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)含量。结果 模型组大鼠结肠粘膜上皮细胞MDA、LDH和MPO水平增高,CAT、GSH-Px和SOD含量减少。不同单位rHpCAT呈剂量依赖性的减少LDH释放,抑制MDA和MPO的形成,而使CAT、GSH-Px及SOD恢复到正常水平。结论 重组幽门螺杆菌过氧化氢酶对大鼠结肠粘膜氧化损伤具有保护作用。

Effects of recombinant Helicobacter pylori catalase on oxidative stress in colonic mucosal epithelial cells

Objective To investigate the effects of recombinant Helicobacter pylori catalase (rHpCAT)on oxidative stress in rat colonic mucosal epithelial cells. Methods Oxidative stress model was established by hydroxyl generated from Fenton reaction in cultured colonic mucosal epithelial cells isolated from normal rats, in the model of which the effects of rHpCAT were observed. The cells were divided into normal control, model, 5-aminosalicvlic acid (5-ASA, 0.1 mmol/L), and rHpCAT (1×10⁵, 1×10⁶, and 1×10⁷ U/kg, respectively) groups. At the end of the experiment, the content of lactic dehydrogenase (LDH), malondialdehyde (MDA), myeloperoxidase (MPO), glutathione peroxidase (GSH-Px), catalase (CAT) and, superoxide dismutase (SOD) were detected in the culture supernatant. Results The contents of LDH, MDA and MPO were elevated while those of GSH-Px, CAT and SOD reduced in the model group. rHpCAT at different doses reduced the release of LDH, depressed the contents of MDA and MPO, and increased the contents of GSH-Px, SOD and CAT. Conclusion rHpCAT has protective effects against rat colonic mucosal oxidative damage.