Effect of tangeretin on ovalbumin-provoked allergic respiratory asthma in Swiss albino mice

Purpose: To evaluate the effect of tangeretin on ovalbumin (OVA)-induced allergic respiratory asthma in Swiss albino mice.Methods: Mice were injected intraperitoneally with 50 μg OVA dissolved in water and 1 mg of aluminium hydroxide (alum) on the first day, and on day 12. On days 22, 26 and 30, the mice were exposed to 1 % OVA for 30 min. Mice in the asthma control group received saline via the same route. Tangeretin (50 or 100 mg/kg body weight) was given orally from day 1 to day 30. On the day of sensitization and challenge, tangeretin (50 or 100 mg/kg body weight) was injected 30 min prior to the treatment. Bronchial function, degree of inflammation, broncho-alveolar lavage fluid (BALF), levels of IL-4, IL-5, IL-13 and IFN-γ in BALF, serum total IgE, OVA-specific IgE, IgG1 and IgG2a, as well as histopathology of lungs were determined.Results: Tangeretin administration led to significant reduction in airway sensitivity, and significant decreases in leukocyte, macrophage, and eosinophil counts (p < 0.05). It also brought about significant decreases in the levels of the pro-inflammatory cytokines (IL-4, IL-5 and IL-13) in both BALF and serum (p < 0.05). In addition, tangeretin reversed the OVA-induced histopathological anomalies in the lungs.Conclusion: These results demonstrate that tangeritin exerts protective effects against OVA-induced allergic respiratory asthma in Swiss albino mice, and that the drug can potentially be developed for the management of allergic asthma.Keywords: Allergic asthma, Inflammation, Cytokines, Ovalbumin, Tangereti