虎杖苷通过p38 MAPK/Nrf2/HO-1通路减轻小鼠哮喘模型气道炎症

摘要

目的 研究虎杖苷能否减轻小鼠哮喘模型气道炎症,并探究其作用是否与p38 MAPK/Nrf2/HO-1通路有关.方法 建立OVA诱导的小鼠哮喘模型,腹腔注射30、45 mg·kg-1的虎杖苷进行治疗,对照组用生理盐水代替.HE、PAS、Masson染色观察肺组织病理学变化;Diff-Quick染色分类及计数支气管肺泡灌洗液(BALF)中的炎性细胞总数;ELISA法检测小鼠BALF中IgE的表达水平;双氢罗丹明(DHR)-123方法检测小鼠BALF细胞中ROS含量;试剂盒检测小鼠BALF中抗氧化酶SOD、CAT活性及MDA含量;免疫组化检测肺组织中HO-1的表达;Western blot法检测小鼠肺组织中p-p38 MAPK的表达;Western blot及real-time PCR检测小鼠肺组织中Nrf2、HO-1的蛋白和mRNA表达.结果 虎杖苷治疗明显降低小鼠肺组织中的炎性细胞浸润、黏液分泌和杯状细胞的增生以及胶原沉积;减少BALF中炎症细胞数量,降低BALF中总IgE及ROS的表达水平;提高SOD、CAT等抗氧化酶的水平,并降低MDA水平;虎杖苷降低小鼠肺组织中p38 MAPK的磷酸化,提高Nrf2、HO-1 mRNA及蛋白的表达,并促进Nrf2的核转移.结论 在OVA诱导的哮喘小鼠模型中,虎杖苷通过抗氧化途径发挥抗炎作用,其作用机制可能是通过p38 MAPK/Nrf2/HO-1通路实现的.%Aim To investigate whether polydatin re-duces airway inflammation in asthmatic mouse model and explore whether this pathway is related to p38 MAPK/Nrf2/HO-1 . Methods After the establish-ment of the OVA-induced asthmatic mouse model, the animals were injected with 30 mg·kg-1 and 45 mg· kg-1 of polydatin diluted in 0. 2 mL normal saline, while the control group was replaced by normal saline. HE, PAS and Masson staining were used to observe the pathological changes of lung tissue. Diff-Quick staining was used to classify and count the number of inflamma-tory cells in BALF. ELISA was used to detect IgE ex-pressions in BALF. The content of ROS in BALF cells was detected by DHR-123 . The activities of antioxidant enzymes SOD, CAT and MDA in BALF were detected by the enzyme-linked immunosorbent assay kit. The expression of HO-1 in lung tissue was detected by im-munohistochemistry. The protein and mRNA expres-sions of Nrf2 and HO-1 in lung tissue of mice were de-tected by Western blot and RT-PCR. Results Poly-datin treatment significantly reduced inflammatory cell infiltration mucosal secretion, goblet cell proliferation and collagen deposition in the lung tissue of mice, and decreased the number of inflammatory cells and the ex-pression of total IgE and ROS in BALF. It also in-creased the levels of antioxidant enzymes such as SOD and CAT, and lowered the level of MDA. Polydatin re-duced the phosphorylation of p38 MAPK in the lung tissue of mice, enhanced the levels of mRNA and pro-tein expressions of Nrf2 and HO-1 and promoted the nuclear transfer of Nrf2 . The above effects of polydatin were dose-dependent. Conclusions Polydatin exerts anti-oxidative effects in OVA-induced asthmatic mouse model via anti-oxidant pathway. The mechanism may be achieved through the p38 MAPK/Nrf2/HO-1 path-way.