The influence of Lactobacillus salivarius on IgE, eosinophil cationic protein and transforming growth factor-β in serum and lung tissue homogenates of asthmic Balb/c mouse

Abstract

Objective To explore the influence of Lactobacillus salivarius on IgE, eosinophil cationic protein(ECP) and transforming growth factor(TGF)-β of serum and lung tissue homogenates of asthmic Balb/c mouse. Methods Thirty female Balb/c mice weighing 16-18 g(4 weeks old), SPF grade, were randomly divided into three groups: normal control group(group A), asthma group(group B), asthma combined Lactobacillus salivarius group(group C). Acute asthma model was established applying ovalbumin, behavioral changes were observed in mice, the changes in airway inflammation and the number changes of tracheal cilia were observed by pathological HE staining and the electron microscope respectively.The levels of IgE, ECP and TGF-β in the serum and lung tissue homogenate were measured by ELISA method. Results (1)The mice in group B presented obvious restlessness, head and facial itching, scratching, shortness of breath, perioral cyanosis with abdominal breathing, sneezing, stooping, forelimbs shrinkage, urine and feces incontinence and other asthma acute phase performances in 5-10 minuts after 4% ovalbumin saline solution atomization excitation, the above reaction alleviated in group C compared to group B. (2) Pathology of HE staining in group B showed the thickening bronchial wall, narrow lumen, peribronchial and perivascular infiltration with a large number of eosinophil-based inflammatory cells, lumen with many inflammatory secretions, pathological changes in lung tissue of mice in group C significantly alleviated compared with group B. Under the electron microscope, the number of cilia in group B significantly decreased compared with group A, while group C significantly increased compared with group B. (3) Expression levels of serum IgE and ECP in group C were significantly lower than those in group B[(0.86±0.14) μg/ml vs.(1.30±0.12) μg/ml; (2.30±0.15) ng/ml vs.(3.41±0.15) ng/ml, P<0.05, respectively]. The contents of lung tissue homogenate IgE[(0.97±0.06) μg/ml] and ECP[(5.88±0.13) ng/ml] in group C significantly decreased, respectively, compared with the IgE[(1.13±0.05) μg/ml] and ECP[(8.08±0.15) ng/ml] in group B(P<0.05). The levels of serum TGF-β[(0.17±0.01) μg/ml] and lung tissue homogenates TGF-β[(0.18±0.01) μg/ml] in group C were higher than the serum TGF-β[(0.13±0.01) μg/ml] and lung tissue homogenates TGF-β[(0.15±0.01) μg/ml] in group B, respectively, the differences were statistically significant(P<0.05). Conclusion Lavage with Lactobacillus salivarius before sensitization could alleviate clinical symptoms of asthmatic mice, as well as reduce airway inflammation in some degree, TGF-β may be involved in the mechanism of Lactobacillus salivarius playing a protective role. Key words: Lactobacillus salivarius; Asthma; IgE; ECP; TGF-β