Effect of essential oil on allergic airway changes induced by histamine and ovalbumin in experimental animals.

OBJECTIVE

Edgew (Apiaceae) is used in traditional medicine for treatment of several diseases including bronchial asthma. The present investigation was aimed to evaluate broncho-relaxant activity of essential oil in histamine and ovalbumin (OVA)-induced broncho constriction in experimental animals.

MATERIALS AND METHODS

Airway was induced using histamine aerosol in guinea pigs ( = 24) and OVA aerosol in albino mice ( = 24). The number of inflammatory cells, namely, absolute eosinophils count in blood, total immunoglobulin E (IgE) in serum, eosinophils, and neutrophils in bronchoalveolar lavage fluid (BALF) and histopathological examination of lung tissues were investigated in oil and dexamethasone-treated groups. oil 200 μL/kg was given orally, and dexamethasone 2 mg/kg was given intraperitoneal. Both the treatments were repeated daily for 7 days. Results were analyzed by one-way ANOVA, and ≤ 0.05 was considered statistically significant.

RESULTS

Treatment with essential oil significantly ( < 0.001) increased the time of preconvulsive dyspnea in histamine-induced guinea pigs. Oral treatment of oil significantly ( < 0.001) decreased absolute blood eosinophil count (from 325 ± 3.69 to 200 ± 3.05 cells/mm), serum level of IgE (from 6.10 ± 0.05 to 0.70 ± 0.08 IU/L), and the number of eosinophils (from 11.0% ±1.41% to 3.0% ±0.51%), neutrophils (from 13.0% ±1.12% to 5.0% ±1.39%) in BALF. Histopathological changes observed in lungs of untreated group were marked suppressed by treatment with oil.

CONCLUSION

The essential oil of has bronchorelaxation in both histamine and OVA-induced bronchoconstriction in animals. The traditional use of against asthma could be attributed to its bronchodilator property as observed in the present study.