Effect of epigallocatechin-3-gallate on airway inflammation and Treg/Th17 immune balance of mice with obese asthma / 吉林大学学报(医学版)

ABSTRACT

Objective: To investigate the regulatory effect of epigallocatechin-3-gallate (EGCG) on the immune imbalance of regulatory T lymphocytes/helper T lymphocytes 17 (Treg/Th17) in the mice with obese asthma, and to provide the basis for the treatment of obese asthma by EGCG. Methods: A total of 40 C57BL/6J mice were randomly divided into normal control group (fed with chow diet), obese group (fed with high fat diet), obese asthma group [fed with high fat diet and sensitized and challenged with ovalbumin (ova)], EGCG intervention group (20 mg middot; kg-1 EGCG was administered intraperitoneally 1 h before challenge of OVA) and dexamethasone intervention group (2 mg middot; kg-1 dexamethasone was administered intraperitoneally 1 h before challenge of OVA), and there were 8 mice in each group. The edhanced pause (Penh) values of the mice in various groups were measured with non-invasive lung function instrument; the pathomorphology of lung tissue of the mice in various groups were observed by HE staining, and the inflammation scores were evaluated by semi-quantitative method for HE staining section; the levels of interleukin-10 (IL-10) and interleukin-17A (IL-17A) in bronchoalveolar lavage fluid (BALF) and adiponectin and leptin in serum of the mice in various groups were detected by ELISA method, and the percentages of Treg and Th17 in spleen tissue of the mice in various groups were detected by flow cytometery. Results: Compared with normal control group, the body weight of the mice in obese group was increased (P<0. 05); it was 1. 67 times the average weight of the mice in normal control group. Compared with normal control group, the Penh value and inflammation score of the mice in obese asthma group were increased (P< 0. 05); the leptin level in serum of the mice in obese asthma group was increased (P<0. 05); the IL-17 level in BALF of the mice in obese asthma group was increased (P<0. 05) and IL-10 level in BALF of the mice in obese asthma group was decreased (P<0. 05); the percentage of Th17 in spleen tissue of the mice in obese asthma group was increased (P<0.05) and the percentage of Treg in spleen tissue of the mice in obese asthma group was decreased (P<0. 05). Compared with obese asthma group, the Penh value and inflammation score of the mice in EGCG intervention group were decreased (P<0. 05); the leptin level in serum of the mice in EGCG intervention group was decreased (P<0. 05); the IL-17 level in BALF of the mice in EGCG intervention group was decreased (P<0. 05) and IL-10 level in BALF of the mice in EGCG intervention group was increased (P<0. 05); the percentage of Th17 in spleen tissue of the mice in EGCG intervention group was decreased (P<0. 05) and the percentage of Treg in spleen tissue of the mice in EGCG intervention group was increased (P < 0. 05). Conclusion: Treg/Th17 immune imbalance exists in the mice with obese asthma. EGCG could inhibit the airway inflammation and hyperresponsiveness in the mice with obese asthma and improve the Treg/Th17 immune imbalance.