【摘要】 目的探讨迷迭香酸(RA)对于PM2.5诱发变应性鼻炎(AR)大鼠模型氧化应激反应的防护作用。方法将32只清洁级Sprague-Dawley雌性大鼠随机分为4组:正常对照组(NC组)、AR模型组(AR组)、AR模型PM2.5暴露组(ARE组)和RA干预PM2.5暴露AR模型组(RA组),每组8只。卵清蛋白(OVA)致敏法制备大鼠AR模型。采用PM2.5动物吸入性暴露系统进行PM2.5吸入暴露(浓度1 000μg/m~3),3 h/d,持续30 d。RA剂量为20 mg/(kg·d),连续7 d腹腔注射(第24～30天)。观察不同组别大鼠的喷嚏、挠鼻症状。检测大鼠鼻黏膜中超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量。酶联免疫吸附试验(ELISA)检测血清OVA特异性IgE(OVA-sIgE)水平。免疫组织化学荧光检测鼻黏膜细胞中核因子E2相关因子2(Nrf2)蛋白水平。苏木精-伊红(HE)染色观察各组大鼠鼻黏膜组织病理学改变。结果 ARE组喷嚏、挠鼻次数较AR组增多,RA组较ARE组减少,差异具有统计学意义(P<0.01)。AR组、ARE组血清中OVA-sIgE明显高于NC组,RA组较ARE组降低,差异有统计学意义(P值均<0.01)。NC组、AR组、ARE组、RA组鼻黏膜SOD活性分别为(135.67±4.33)、(81.01±9.32)、(25.50±12.84)、(127.92±15.34)U/mg,MDA含量分别为(29.69±4.21)、(51.34±5.23)、(73.13±3.14)、(50.19±2.99)nmoL/mg。SOD水平自NC组、AR组到ARE组,呈逐渐降低趋势,而MDA含量呈逐渐升高趋势(P<0.01)。RA组大鼠SOD活性增加,MDA含量减少(P<0.01)。免疫荧光结果显示,AR组和ARE组Nrf2蛋白表达较NC组增高(P<0.01),RA组较ARE组降低(P<0.01)。组织病理学显示,NC组大鼠鼻黏膜上皮细胞排列整齐,结构完整;AR组上皮细胞排列紊乱,结构肿胀;ARE组上皮细胞脱落,间质细胞增多,腺体肿胀,黏膜下血管充血。RA干预后减轻了鼻黏膜损伤。结论 RA可以减轻PM2.5诱导的AR大鼠模型氧化应激反应和鼻黏膜损伤,并缓解AR症状,为PM2.5诱发AR的防治提供理论依据。更多还原

【Abstract】 Objective To explore the protective effect of rosmarinic acid(RA) on oxidative stress reaction in rats of allergic rhinitis(AR) induced by PM2.5. Methods Thirty-two clean SpragueDawley female rats were randomly divided into four groups:normal control group(NC group), AR model group(AR group), AR model exposed to PM2.5 group at 1 000 μg/m~3, 3 hours per day, for continuous 30 days(ARE group), and RA intervention to AR model PM2.5 exposure group(RA group). RA group were administrated 20 mg/kg of RA via intraperitoneal injection every day from day 24 to 30. The symptoms of sneezing and nasal scratching in different groups of rats were observed. The levels of superoxide dismutase(SOD) activity and malondialdehyde(MDA) content in the nasal mucosa of rats were detected. The level of serum OVA-specific Ig E was detected by enzyme linked immunosorbent assay(ELISA). The changes of nuclear factor-E2 related factor 2(Nrf2) in nasal mucosa cells were tested by immunofluorescence. The pathological changes of nasal mucosa of rats in each group were observed by hematoxylin eosin(HE) staining. Results PM2.5 significantly increased the number of sneeze and nasal rubs in the rats with ARE. RA alleviated these symptoms. Statistically significant differences of OVA-specific Ig E were observed in AR group and ARE group comparing to NC group. RA decreased OVA-specific Ig E levels significantly. The SOD activity of nasal mucosa in NC group, AR group, ARE group and RA group were(135.67±4.33),(81.01 ±9.32),(25.50±12.84),(127.92±15.34) U/mg, respectively. The MDA contents of nasal mucosa in NC group, AR group, ARE group and RA group were(29.69±4.21),(51.34±5.23),(73.13±3.14),(50.19±2.99) nmo L/mg, respectively. Except RA group, the other three groups showed a downward trend in the levels of SOD and an upward trend in the levels of MDA. RA increased SOD activities and deceased MDA content comparing to ARE group. Immunofluorescence results showed that the expression of Nrf2 protein in nasal mucosal epithelial cells of AR group and ARE group was higher than that of NC group(P<0.01), and Nrf2 protein of RA group was lower than that of ARE group(P<0.01). Pathological results showed that the nasal mucosal epithelial cells in NC group were neatly arranged and the structure was complete. The nasal mucosal epithelial cells in AR group were arranged disorderly and the tissue structure was swollen. Cell shedding, interstitial cell proliferation, swelling of the glands, and submucosal vascular congestion was found in ARE Group. RA group showed reduced eosinophilic infiltration and orderly lining of the mucosa epithelium comparing to ARE group. Conclusions RA alleviates the symptoms of AR rats exposed to PM2.5 inhalation by regulating oxidative stress. It provides a theoretical basis for RA in prevention and treatment of PM2.5 induced AR.更多还原