Clerodendrum serratum extract attenuates production of inflammatory mediators in ovalbumin-induced asthma in rats

Abstract

In the present study, ethanolic extract of Clerodendrum serratum roots was investigated for its potential to reverse some features of bronchial asthma in ovalbumin-induced murine model of asthma. Clerodendrum serratum commonly called bharangi, (family Solanaceae) is a well-known anti-allergic drug in Asian folk system of medicines. In the present work, pharmacological studies are done to provide scientific evidence for therapeutic potential of plant in allergic asthma. Asthma was induced in experimental rats with allergen suspension of ovalbumin and aluminum hydroxide followed by treatment with dexamethasone (2.5 mg/kg, po) or C. serratum root extract (0.53 and 5.3 mg/kg, b. w., po). Biomarkers of inflammatory response including cell counts, immunoglobulin E, cytokines such as interleukin (IL) -4, -5, -1β, tumor necrosis factor-α (TNF-α), leukotriene (LTD-4), and nitrite concentration in blood as well as bronchial (BAL) fluid were tested. Lung functions in asthmatic and treated animals were evaluated as breathing rate and tidal volume. Treatment with C. serratum extract markedly (p < 0.001, p < 0.01, and p < 0.05) diminished infiltration of inflammatory cells, IgE, cytokines, and nitrites in blood serum and bronchial fluid. Improvement in lung functions (p < 0.05) of asthmatic animals after CSE treatment also supports our findings. Results of the study suggest therapeutic potential of C. serratum in allergic asthma that can be related to ability of plant to attenuate response of inflammatory cells and thereby, production of inflammatory and proinflammatory cytokines in airways.