抗氧化剂茶多酚对哮喘大鼠气道炎症、气道重塑的干预研究

摘要 目的: 研究茶多酚（TP）对支气管哮喘大鼠早期和晚期气道氧化应激水平及气道炎症、气道重塑的影响。 方法: 以卵蛋白为致敏原，通过反复激发，制备大鼠慢性哮喘模型。将48只大鼠随机分为6组：对照组、哮喘组、早期布地奈德（BUD）组、晚期BUD组、早期TP组、晚期TP组。早BUD组、早TP组在造模前2周药物干预，晚BUD组、晚TP组在造模5周后药物干预。造模12周时观察指标①肺组织病理：测定支气管壁的平滑肌面积、胶原沉积面积，以及肺组织转化生长因子-?1（TGF-?1）的表达。②肺组织TGF-β1含量、丙二醛（MDA）含量及超氧化物歧化酶（SOD）活力。 结果: ①早TP组、晚TP组、早BUD组干预后各项气道重塑指标较哮喘组均有改善（P＜0.01或P＜0.05)，早TP组改善最明显(P均＜0.01)。晚BUD组较哮喘组无明显改善(P＞0.05)。②哮喘组肺组织中MDA含量明显上升，SOD活性显著下降，与对照组有显著性差异(P＜0.01)；各药物干预后SOD活性均上升，MDA含量均下降，以早TP组最明显(P＜0.01)。③相关性分析表明，SOD活性与MDA含量呈负相关，支气管壁的胶原沉积面积与MDA含量呈正相关。 结论: 茶多酚可能通过清除氧自由基，减少气道炎症及氧化应激，从而改善或延缓气道重塑的发生。

The effects of tea polyphenols on oxidative stress level,airway inflammation and airway remodeling in asthmatic rats

Abstract Objective: To observe the effects of tea polyphenols (TP) on oxidative stress level, airway inflammation and airway remodeling in asthmatic rats of early stage and late stage. Methods :SD rats were sensitized and challenged repeatedly by ovalbumin to establish chronic asthma airway remodeling. 48 rats were randomly divided into 6 groups, a normal saline group, an asthma group, an early budesonide group (early BUD group), a late budesonide group (late BUD group), an early TP group and a late TP group . Drugs were administrated 2 weeks before sensitizing in early BUD group and early TP group, while being administrated 5 weeks after sensitizing in late BUD group and late TP group. The lung tissues were harvested from the rats 12 weeks after sensitizing. Smooth muscle area, collagen deposition area were assessed and the expressions of transforming growth factor--?1（TGF-?1）in bronchi and lung tissues were observed by immunohistochemistry. The contents of TGF-?1 and malondialdehyde (MDA) were tested as well as superoxide dismutase (SOD) vitalities were measured. Results: The indicators of airway remodeling significantly improved in the early TP group, late TP group and early BUD group as compared with those in asthma group（P＜0.01 or P＜0.05), the most obvious in early TP group( all P ＜0.01). No significant differences were found between late BUD group and asthma group (P＞0.05). The asthma group also showed increased MDA content and decreased SOD vitality, both being significantly different from that in normal group (P＜0.01). SOD vitality increased and MDA content decreased in each therapeutic group after intervention. SOD vitality had a negative correlation with MDA content. In addition, a positive correlation between collagen deposition area of bronchial wall and MDA content was also found. Conclusion: Tea polyphenols intervention could inhibit or delay the formation and development of airway remodeling maybe by controlling the level of oxidative stress and downregulating airway inflammation in rats. Early drug intervention by Tea polyphenols or BUD could inhibit airway remodeling. Tea polyphenols may delay airway remodeling better than BUD in late stage in asthmatic rats.