The Inhibitory Mechanism Of Catalpol On MUC5AC Hypersecretion In Asthma Mice

Objective:To observe the therapeutic action and inhibition on MUC5 AC hypersecretion in asthma mice of catalpol,and explore the related mechanism.Methods:1.modelling.48 SPF(Specific pathogen Free)mice were fed for one week in advance,then mice were random allocated into 6 groups(8 mice each group): Control group,Model group,DEX group,CL group,CM group and CH group.The suspension of albumin and Al(OH)3 was injected into the abdominal cavity to cause sensitization on 1,8,15 d,in the end,mice were inhaled with 2% OVA from 21-27 d to make asthma model.In the control group,Sensitization liquid and Stimulation liquid were superseded with normal saline.2.pharmacological intervention.On 21-27 d,drugs were intervened by intragastrical administration.Giving administration of drugs 1 hour before the sensitization of OVA.In the control group and model group,drugs were replaced with normal saline.3.observation target.On 25-27 d,the latency was observed and recorded at the ahead 15 min in the period of atomization.On 28 d,enhanced pause(Penh)was measured with a noninvasive lung function instrument.On 28 d,mice were executed after the measure of Penh.OVA-IgE in serum and IL-13,eotaxin,IL-8,MUC5 AC,IL-25,IL-33,MCP-1,IL-23 and so on in BALF were detected with enzyme linked immunosorbent assay(ELISA).Hematoxylin-eosin staining and Periodic Acid-Schiff staining of lung tissue were used to evaluate the pathologic change and goblet hyperplasia changes of lung tissue.The expression of MUC5 AC,FOXA2,EGFR,NFAT3 and P-NFAT3 were evaluated by Immunohistochemistry.The effect of catalpol on ILC2 s in lung tissue was evaluated by Flow Cytometry.Results:1.Latency During the period of atomization,,experimental groups showed dysphoria,picking nose and pruritus,scratching ears and cheeks in embarrassment,messy hair successively compared with control group,then Abdominal spasm and Persistent gasp appeared.With the extension of atomization time,Falling weight and cachexia appeared.With the pharmacological intervention,above-mentioned symptom ameliorated obviously,and latency also extended(P<0.01).2.Airway reactivity The Penh of all groups increased as the dose of methacholine rosed.The Penh of Model group increased significantly at 6.25-50 mg/mL methacholine compared with Control group;CH,CM and DEX inhibited the amplification of Penh at 25-50 mg/m L methacholine(P<0.01 or P<0.05)and CL inhibited the amplification of Penh at 50 mg/m L(P<0.01)compared with Model group.3.Pathology Catalpol significantly ameliorated pathological change in lung tissue and inhibited the hyperplasia of goblet cells.According to the statistics,the positive area rate of goblet cells was significantly decreased(P<0.01)Compared with Control group.4.MUC5 C immunohistochemical result and ELISA result showed that catalpol inhibited the expression of MUC5 AC in bronchus.5.OVA-IgE and inflammatory cytokines ELISA showed that catalpol significantly reduced OVA-IgE in serum and IL-1β,IL-8,IL-13,IL-25,eotaxin,MUC5 AC,MCP-1,TSLP,AREG in BALF.6.signal path of MUC5 AC The result of immunohistochemical showed that catalpol inhibited the FOXA2 and NFAT3 and increased the expression of EGFR,P-NFAT3 in bronchus.Flow cytometry showed that catalpol enhanced the number of ILC2 s in lung tissue.Conclusion:1.On the basis of latency,HE staining,PAS staining,Penh and so on,we confirm the asthma model was successful,and catalpol has obvious anti-asthma effect.2.Catalpol has inhibitory effect on MUC5 AC in airway3.Catalpol has inhibitory effect on several cytokines,and inhibited the concentration of OVA-IgE in serum4.Catalpol plays the role in inhibiting MUC5 AC may be through the signaling pathway which mediated by IL-13 and EGFR.