Anti-inflammatory Effect of Triterpenoic Acids of Eriobotrya japonica (Thunb.) Lindl. Leaf on Rat Model of Chronic Bronchitis
Abstract
This study was designed to investigate the anti-inflammatory effect of Triterpenoic Acids from Eriobotrya japonica (Thunb.) Lindl. (TAL) on chronic bronchitis (CB) in rats. CB model was established by combination of Bacillus Calmette-Guerin (BCG, 5 mg/kg, injected through the caudal vein) and lipopolysaccharide (LPS, 1 g/L, injected through endotracheal intubation). Rats with CB model were treated with TAL (50, 150 and 450 mg/kg) for 3 weeks. The leukocytes in bronchoalveolar lavage fluid (BALF) were counted after Wright staining, the levels of cytokine tumor necrosis factor alpha (TNF-α), interleukin (IL)-8, and IL-10 in the supernatants of lung homogenate were assessed by enzyme-linked immunosorbent assay (ELISA), and the protein expression of nuclear factor kappaB (NF-κB) and intercellular adhesion molecule-1 (ICAM-1) on bronchial epithelium were tested by immunohistochemical staining. As compared to the normal and sham groups, the total number of leukocyte, the differential counts of neutrophils and alveolar macrophage (AM) in BALF, the levels of TNF-α and IL-8 in the supernatants of lung homogenate, and the expression of NF-κB and ICAM-1 on bronchial epithelium in CB rats were significantly increased, while the level of IL-10 was decreased. TAL (50, 150 and 450 mg/kg) attenuated these alterations in model CB rats, which indicates that TAL has anti-inflammatory effect in the rats with CB.
