Luteolin alleviates bronchoconstriction and airway hyperreactivity in ovalbumin sensitized mice

Abstract

Objective and Design: Asthma is an inflammatory disease of the airways and the current focus in managing asthma is the control of inflammation. In this study, we attempted to investigate the anti-asthmatic potential of a plant derived natural compound, luteolin. Material: We used a murine model of airway hyperreactivity, which mimicked some of the characteristic features of asthma. Male BALB/c mice (8-9 weeks) were used for this study.Treatment: Mice (n = 6) were sensitized by intraperitoneal (i.p.) injection of 10 mg of ovalbumin (OVA) on days 0, 7 and 14 followed by aerosol inhalation (5 % OVA) treatments daily beginning from day 19 to day 23. To study its preventive effect, luteolin (0.1, 1.0, and 10 mg/kg body weight; daily) was administered orally during the entire period (0 to 23 day) of sensitization. To study its curative effect, mice were first sensitized and then luteolin (1.0 mg/kg body weight daily) was given orally from day 26 to 32. The airway hyperreactivity, immunoglobulin E (IgE) in the sera, and cytokines (IFN-γ, IL-4 and IL-5) in the bronchoalveolar lavage fluid (BALF) were measured. Results: Both during sensitization and after sensitization, luteolin, at a dose of 0.1 mg/kg body weight, significantly modulated OVA-induced airway bronchoconstriction and bronchial hyperreactivity (p < 0.05). Luteolin also reduced OVA-specific IgE levels in the sera, increased interferon gamma (IFN-γ) levels and decreased the interleukin-4 (IL-4) and interleukin-5 (IL-5) levels in the BALF. Conclusion: Our study showed that luteolin treatment during and after sensitization significantly attenuated the asthmatic features in experimental mice. Therefore, luteolin could be used either as a lead molecule to identify an effective anti-asthma therapy or as a means to identify novel anti-asthma targets.