In Vivo Pharmacological Testing of Herbal Drugs for Anti-Allergic and Anti-Asthmatic Properties.

Abstract

Background:Asthma is a chronic inflammatory disease characterized by reversible airway obstruction, hyperresponsiveness, and remodeling. Asthma prevalence has increased significantly globally over the last decade, and it remains incurable to this date.Aims and Objectives:The present study evaluated some of the antiasthmatic medicinal plants to assess their mode of action.Materials and Method:Animal models for milk-induced leukocytosis, milk-induced eosinophilia, mast cell degranulation, clonidine-induced catalepsy, and active paw anaphylaxis were used to assess the pharmacological effects of Ammi visnaga, Medicago sativa, and Urtica dioica.Results:Mice pretreated with diazepam, methanolic extract of M. sativa, and U. dioica exhibited significant (P < 0.05) inhibition in milk-induced leukocytosis. However, only M. sativa showed statistically significant (P < 0.05) results. All plants showed a statistically significant (P < 0.05) tendency to decrease milk-induced eosinophilia. Methanolic extracts of all plants significantly (P < 0.05) protected mast cells against degranulation by clonidine. A. visnaga and U. dioica significantly (P < 0.05) protected mice against clonidine-induced catalepsy. An acute treatment by M. sativa potentiated the catalepsy, while it significantly inhibited the catalepsy (P < 0.05) upon chronic treatment. In the allergic inflammation model, methanolic extracts of all plants under study decreased paw thickness in a statistically significant manner (P < 0.05).Conclusion:All the three plants in this study demonstrated anti-inflammatory and antihistaminic effects, as well as decreased paw thickness, validate anti-allergic properties. A. visnaga showed a mast cell-stabilizing effect. A. visnaga and U. dioica inhibited the histamine-mediated clonidine-induced catalepsy from mast cells which proves the antihistaminic activity of these plants.