ABSTRACT
Asthma is a chronic allergic disease characterized by airway inflammation, airway hyper-responsiveness (AHR), and mucus hypersecretion. T-lymphocytes are involved in the pathogenesis of asthma, mediating airway inflammatory reactions by secreting cytokines. The phosphoinositide 3-kinase (PI3K) and Notch signaling pathways are associated with T cell signaling, proliferation, and differentiation, and are important in the progression of asthma. Thus, compounds that can modulate T cell proliferation and function may be of clinical value. Here, we assessed the effects of tangeretin, a plant-derived flavonoid, in experimental asthma. BALB/c mice at postnatal day (P) 12 were challenged with ovalbumin (OVA). Separate groups of mice (n=18/group) were administered tangeretin at 25 or 50 mg/kg body weight by oral gavage. Dexamethasone was used as a positive control. Tangeretin treatment reduced inflammatory cell infiltration in bronchoalveolar lavage fluid (BALF) and also restored the normal histology of lung tissues. OVA-specific IgE levels in serum and BALF were reduced. AHR, as determined by airway resistance and lung compliance, was normalized. Flow cytometry analyses revealed a reduced Th17 cell population. Tangeretin reduced the levels of Th2 and Th17 cytokines and raised IFN-γ levels. PI3K signaling was inhibited. The expressions of the Notch 1 receptor and its ligands Jagged 1 and 2 were downregulated by tangeretin. Our findings support the possible use of tangeretin for treating allergic asthma.
Subject(s)
Animals , Mice , Asthma/drug therapy , Signal Transduction/drug effects , Anti-Asthmatic Agents/therapeutic use , Flavones/therapeutic use , Asthma/immunology , Cytokines/drug effects , Cytokines/immunology , Th2 Cells/drug effects , Th2 Cells/immunology , Th1 Cells/drug effects , Th1 Cells/immunology , Disease Models, Animal , Proto-Oncogene Proteins c-akt/drug effects , Proto-Oncogene Proteins c-akt/immunology , Th17 Cells/drug effects , Th17 Cells/immunology , Animals, Newborn , Mice, Inbred BALB CSubject(s)
Humans , Antioxidants/pharmacology , Endothelium, Vascular/drug effects , Oxidative Stress , Flavones/therapeutic use , Fruit/therapeutic use , Wine/analysis , Caffeic Acids/therapeutic use , Antioxidants/therapeutic use , Catechin/therapeutic use , Cholesterol, LDL/drug effects , DNA Damage , Flavones/pharmacology , Onions/therapeutic use , Quercetin/therapeutic use , Rosales/anatomy & histology , Rosales/therapeutic use , Rutin/therapeutic use , VegetablesABSTRACT
Ternatin, a tetramethoxy flavone isolated from Egletes viscosa Less (Compositae), was tested for its efficacy in modulating mouse passive cutaneous anaphylaxis (PCA) and rat carrageenan-induced pleurisy. Ternatin (12.5, 25 and 50 mg/kg, ip) caused a dose-dependent inhibition of IgG antibody-mediated 1.5-h homologous PCA as well as IgE antibody-mediated 48-h homologous PCA in 2-month old mice (N = 5 per group). The inhibitory activity of ternatin was more potent on IgE-mediated PCA (47-79%) than on IgG (45-59%). In the rat carrageenan pleurisy test, ternatin (25 and 50 mg/kg, ip) reduced the response to carrageenan at 5 h both by decreasing exudate volume (33-40%) and leukocyte number (60%) in 5-6-month old rats (N = 6 per group). In contrast, indomethacin (2 mg/kg, po), a known cyclooxygenase inhibitor, showed greater potency in the inhibition of exudate volume (57%) and leukocyte number (77%). These results show that ternatin has both anti-inflammatory and anti-anaphylactic properties and suggest that it may be a useful alternative to anti-allergic drugs of the disodium cromoglycate (DSCG) type for use in bronchial asthma