Effects Of Oxymatrine On Expressions Of IL-10, CTLA-4 And IL-17 In Lung Tissues Of Asthmatic Rats

Objective: To observe the efficacy of oxymatrine with different dosage on the asthmatic rats and to explore the mechanisms.Methods: Forty healthy female SD rats were randomized into five groups with 8 rats in each group. A group(Asthma group) : The rats were intraperitoneally injected OVA/Al(OH)3 on 1 and 8 days. 5% OVA atomization spray stimulated the rats 60 min every day on 15 to 21 days. B group(Low-dose oxymatrine group): The rats were intraperitoneally injected oxymatrine(50 mg/kg) 30 minutes before atomization. C group(Middle-dose oxymatrine group): The rats were intraperitoneally injected oxymatrine(100 mg/kg) 30 minutes before atomization. D group(High-dose oxymatrine group): The rats were intraperitoneally injected oxymatrine(150 mg/kg) 30 minutes before atomization. E group(Control group): The rats were intraperitoneally injected normal saline on 1 and 8 days. Normal saline atomization spray stimulated the rats 60 min every day on 15 to 21 days. During the course of experiment the rats' activity, diets and respiration were observed on time in every group. All rats were sacrificed at 24 hours after the last 5% OVA atomization stimulation. The lung tissue were observed under microscope after HE dyeing. The expressions of IL-10, CTLA-4 and IL-17 were determined by immunohistochemistry method with image analyze system. The mRNA expressions of IL-10, CTLA-4 and IL-17 were detected by RT-PCR. The protein expressions of IL-10, CTLA-4 and IL-17 were examined by Western blot.Results:1. Rats' living conditions after sensitization and stimulationThe rats of asthma group gradually appeared irritable, scratching and drowsy with increasing respiratory frequency and poor appetite. Some of the rats appeared hair loss, slow moving and purple skin. The most serious rats could appear wheezing sound. Rats of oxymatrine intervention groups were better than the asthma group. Rats in control groups were normal.2. Lung tissue changes of the experimental rats in each groupHE dyeing: lung tissue of control group showed that the bronchial tube diameter was normal and cells associated with inflammation had not moved into the lung. Results of asthma group showed that the bronchial tube diameter of rats in asthma group was narrow with thickening tube wall. There were lots of inflammatory cells in the lung and most of them were macrophage and lymphocyte, with airway epithelium lodging and lumen secretion increasing. While after intervention of oxymatrine, airway stenosis and inflammatory cells invasion became better. Experiment evidence showed positive correlation between different dosage of oxymatrine and pathological changes in the lung.3. The expressions of IL-10, CTLA-4 and IL-17 in lungs of experimental rats in each groupThe expressions of IL-10 and CTLA-4 were determined by immunohistochemistry method which showed that the expressions of IL-10 and CTLA-4 in the asthma group were the lowest and the expressions of IL-10 and CTLA-4 in the control group were the highest, with significant differences(P<0.05). The expression of IL-10 and CTLA-4 increased with the increasing of the dosage of oxymatrine. Comparing the high-dose oxymatrine group with control group, there were no obvious difference between them(P>0.05).The expression of IL-17 was determined by immunohistochemistry method which showed that the expression of IL-17 in the asthma group were the highest and the expression of IL-17 in the control group was the lowest, with significant differences(P<0.05). The expression of IL-17 decreased with the increasing of the dosage of oxymatrine. Comparing the high-dose oxymatrine group with control group, there were no obvious difference between them(P>0.05).4. The mRNA expressions of IL-10, CTLA-4 and IL-17 in lungs of experimental rats in each groupThe mRNA expressions of IL-10 and CTLA-4 in the asthma group were the lowest, while the mRNA expressions of IL-10 and CTLA-4 in the control group were the highest, with significant differences(P<0.05). The expressions of IL-10 and CTLA-4 mRNA increased with the increasing of the dosage of oxymatrine. Comparing the high-dose oxymatrine group with control group, there were no obvious difference between them(P>0.05).The mRNA expression of IL-17 in the asthma group was the highest, while the mRNA expression of IL-17 in the control group was the lowest, with significant differences(P<0.05). The expression of IL-17 mRNA decreased with the increasing of the dosage of oxymatrine. Comparing the high-dose oxymatrine group with control group, there were no obvious difference between them(P>0.05).5. The protein expressions of IL-10, CTLA-4 and IL-17 in lungs of experimental rats in each groupThe protein expressions of IL-10 and CTLA-4 in the asthma group were the lowest while the protein expressions of IL-10 and CTLA-4 in the control group were the highest, with statistical significances(P<0.05). The expressions of IL-10 and CTLA-4 protein increased with the increasing of the dosage of oxymatrine. Comparing the high-dose oxymatrine group with control group, there were no statistical significances between them(P>0.05).The protein expression of IL-17 in the asthma group was the highest while the protein expression of IL7 in the control group was the lowest, with statistical significances(P<0.05). The expression of IL-17 protein decreased with the increasing of the dosage of oxymatrine. Comparing the high-dose oxymatrine group with control group, there were no statistical significances between them(P>0.05).Conclusion:1. Oxymatrine had effects on improving symptoms and inhibiting inflammation of lung tissue in asthma rats.2. The inhibition mechanism of oxymatrine on asthma rats may be related to promoting the expressions of IL-10 and CTLA-4 and suppressing the expressions of IL-17 in lung tissues of asthma rats.