[Preventive and therapeutic effects and mechanism of Xiaoer Feike Granules on chronic bronchitis induced by lipopolysaccharide in rats].

The aim of this paper was to investigate the preventive and therapeutic effects of Xiaoer Feike Granules(XEFK) on chronic bronchitis in rats and its mechanism. Except for 10 rats in the blank group, the remaining 50 of the 60 SD rats were used to establish a model of chronic bronchitis induced by LPS. On the 22 nd day, the model rats were randomly divided into 5 groups according to their body weight, and administrated with purified water, Keteling Capsules 0.11 g·kg~(-1), XEFK 3.2, 1.6 and 0.8 g·kg~(-1)(the dosing concentrations were 0.32, 0.16, 0.08 g·mL~(-1), respectively). These rats took the corresponding drug orally once a day, for consecutive 21 days. The rats were anesthetized 1 hour after the last administration, and the lavage bronchus and alveoli were collected. Then, after the fixation of the smear, neutrophils were counted microscopically, and the contents of glutathione peroxidase(GSH-Px), superoxide dismutase(SOD) and malondialdehyde(MDA) in the bronchoalveolar lavage fluid(BALF) were detected by colorimetric method. Flow cytometry was used to detect the content changes of T cell subsets CD4~+, CD8~+, CD4~+/CD8~(+ )in serum. Hemorheology related indexes were detected by automatic hemorheology. Enzyme-linked immunosorbent assay(ELISA) was used to detect the contents of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-2, IL-6 and IL-10 in serum. The expression of TNF-α and IL-10 mRNA in lung was detected by Real-time quantitative PCR(RT-qPCR). HE staining was used to observe the pathological changes in the bronchitis tissues. Compared with the model group, XEFK high and medium dose groups could significantly reduce the contents of neutrophils and MDA in bronchial lavage fluid, and increase the activities of GSH-Px and SOD in BALF, and repair the chronic inflammatory cell infiltration and lymphoid tissue hyperplasia in the bronchial mucosal layer and submucosal layer. The high-dose group could reduce the plasma viscosity of rats, but there was no statistical difference in other hemorheological indexes. CD4~+, CD8~+, CD4~+/CD8~+, IL-2 and IL-10 contents in each dose group were significantly increased, and TNF-α, IL-1β and IL-6 contents were significantly decreased in serum. Each dose group could significantly down-regulate the expression level of TNF-α mRNA in the lung and increase the expression of IL-10 mRNA. XEFK could reduce lipid peroxidation, increase the content of peripheral blood T cell subsets, regulate the release and secretion of inflammatory factors, and repair the morphological and pathological changes of bronchial tissue. Its mechanism might be related to the improvement of inflammatory response and the enhancement of immune function.