Effects of Honokiol on airway inflammation in asthmatic mice exposed to PM2.5 and its mechanism
10.3760/cma.j.issn.2095-428X.2018.05.012
- VernacularTitle:和厚朴酚对PM2.5暴露哮喘小鼠呼吸道炎症的影响及其机制
- Author:
Feng HAN
1
;
Huicong FU
;
Xiaoxia LU
;
Yurong FANG
;
Jiali XU
;
Liqiong ZHANG
;
Qing DU
;
Zongqi DONG
Author Information
1. 华中科技大学同济医学院附属武汉儿童医院呼吸内科
- Keywords:
Asthma;
Particulate matter;
Toll-like receptors 4;
Nuclear factor-κB;
Honokiol
- From:
Chinese Journal of Applied Clinical Pediatrics
2018;33(5):373-377
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the protective effect of Honokiol on the airway inflammation induced by particulate matter 2.5(PM2.5)in the asthmatic mice and its mechanism.Methods Fifty male specific pathogen free (SPF)Balb/c mice were randomly divided into 5 groups.Group A:normal control group;group B:asthmatic model group;group C:PM2.5 exposure asthmatic group;group D:TAK -242 group;group E:Honokiol group. Asthmatic mouse models were established by ovalbumin(OVA)sensitization and challenge.On days 0 and 7,the mice in B-E groups were injected intraperitoneally with injection 100 mg/L OVA and aluminum hydroxide for sensitization;on days 14 to 21,10 g/L OVA solution was given 30 min per day to challenge.During challenge phrase,the mice in C -E groups received intratracheal injection of PM2.5,every other day,4 times totally.On this basis,the mice in group D re-ceived TAK-242 intraperitoneal injection,and the mice in group E received honokiol intragastric administration.Group A was given saline instead of OVA.Animals were sacrificed 24 h after the final inhalation challenge,and the bronchoal-veolar lavage fluid(BALF)of the left lung was used for differential inflammatory cell counts.The expressions of Toll-like receptors 4(TLR4)and nuclear factor(NF)-κB at mRNA level were detected by real-time quantitative PCR. Flow cytometry analysis was performed to measure the levels of Th17 and Treg cells.Results Compared with group A,mice in group B and group C expressed more serious disorders of bronchial epithelial cells,alveolar wall congestion and edema,increased mucus secretion in the airway and infiltration of inflammatory cells in the lung,and those in group C were more obvious than those of group B and group E significantly reduced respiratory inflammation;compared with group A[(4.15 ± 1.35)×108/L,0.012 0 ± 0.002 3],the total number of inflammatory cell counts[(16.79 ± 5.62)×108/L and(24.58 ± 13.46)×108/L],eosinophils proportions(0.113 8 ± 0.022 3 and 0.197 8 ± 0.084 9)in group B and group C,were significantly higher,and the differences were statistically significant(all P<0.05);The total number of inflammatory cell counts and eosinophils proportion in group E(8.56 ± 3.28)×108/L and 0.041 5 ± 0.013 5)were significantly lower than those in group C,and the differences were statistically significant(all P <0.05);The expressions of TLR4 mRNA and NF-κB mRNA in group B and C(1.85 ± 0.56,1.82 ± 0.28 and 2.97 ± 0.41,2.83 ± 0.32)were significantly higher,and the differences were statistically significant(all P <0.05);The expressions of TLR4 mRNA and NF-κB mRNA in group E(1.60 ± 0.28,1.54 ± 0.25)was significantly lower than those in group C,and the differences were statistically significant(all P<0.05);the expressions of Th17 in group B and C[(2.89 ± 0.61)% and(4.96 ± 0.27)%]were significantly higher than those of group A[(1.03 ± 0.35)%] (all P<0.05);The expression of Th17 in group E[(1.83 ± 0.23)%]was significantly lower than that of group C,and the differences were statistically significant(P<0.05);the expressions of Treg in group B and C[(4.96 ± 0.35)%and(2.27 ± 0.41)%]were significantly lower than those of group A[(7.37 ± 0.56)%],and the differences were sta-tistically significant(all P<0.05);The expression of Treg in group E was significantly increased[(6.45 ± 0.38)%] compared with that in group C,and the difference were statistically significant(P<0.05);and those of group D and E were improved remarkably.Conclusions Honokiol can relieve PM2.5 exposure of asthmatic airway inflammation through down-regulating the expression of TLR4 and NF-κB and Th17 and regulating the balance of Th17 and Treg cells.
