Hydro-ethanolic extract of Curcuma longa affects tracheal responsiveness and lung pathology in ovalbumin-sensitized rats.

Anti-inflammatory effect of Curcuma longa (C. longa) was shown previously. In the present study, the effect of the plant on tracheal responsiveness and lung pathological features in ovalbumin-sensitized rats was evaluated. Six groups of rats including control (C), ovalbumin (OVA)-sensitized (S), S groups treated with C. longa (CL; 0.75, 1.50, and 3.00 mg/ml equal to 150, 300 and 600 mg/kg/day) and dexamethasone (D; 1.25 μg/ml) were studied (n=8 in each group). The extract of C. longa and dexamethasone were administered with daily drinking water of animals during sensitization period (for 21 days). Following the treatment period, tracheal responsiveness to methacholine and ovalbumin and lung pathological features was investigated. Tracheal responsiveness to methacholine and OVA and lung pathological scores were increased in group S compared to controls (p<0.01 to p<0.001); however, these parameters in groups treated with dexamethasone and two higher concentrations of C. longa were significantly decreased compared to group S (p<0.05 to p<0.001). Tracheal responsiveness to methacholine was decreased from 50 to 400% due to the extract treatment. All concentrations of C. longa significantly decreased interstitial fibrosis compared to group S (p<0.05 to p<0.001). Treatment with the extract resulted to improvement of pathological changes from 20 to 70%. These results showed a preventive effect for C. longa extract on tracheal responsiveness and lung pathological insults in sensitized rats which were similar or even more than those of dexamethasone at used concentrations.