Potential effect of the extract of Zataria multiflora and its constituent, carvacrol, on lung pathology, total and differential WBC, IgE and eosinophil peroxidase levels in sensitized guinea pigs

Guinea pigs sensitized to ovalbumin (OA) were given drinking water alone (group S), drinking water containing dexamethasone, three concentrations of the extract of Zataria multiflora (Z. multiflora) and carvacrol (n = 6, for all groups). Lung pathology, total and differential white blood cell (WBC), serum levels of IgE and eosinophil peroxidase (EPO) were evaluated. Pathological indices, serum IgE and EPO levels, total and differential WBC except lymphocytes in group S significantly increased but lymphocyte decreased compared to the control group (p < 0.05 to p < 0.001). Dexamethasone, all concentrations of the extract and carvacrol treatment caused significant improvement in all parameters compared to group S (p < 0.05 to p < 0.001). The effects of a high concentration of the extract and carvacrol were higher compared to dexamethasone in most parameters (p < 0.05 to p < 0.001). These results showed a preventive effect of Z. multiflora on lung inflammation of sensitized guinea pigs which is perhaps due to its constituent, carvacrol.