Potential effect of the extract of zataria multiflora and its consituent carvacrol on lung inflammation of sensitized guinea pigs

The effects of the extract of Zataria multiflora ( Z. multiflora ) and carvacrol on lung inflammation of sensitized animals were examined. Eight groups of sensitized guinea pigs to ovalbumin (OA) were given drinking water alone (group S), drinking water containing three concentrations of the extract (0.2, 0.4 and 0.8 mg/mL), three concentrations of carvacrol (40, 80 and 160 µg/mL) and dexamethasone (50 µg/mL), (n=6, for all groups). Lung pathology, total and differential WBC in lung lavage and serum levels of IgE and eosinophil proxidase (EPO) were examined. All pathological indices, serum IgE and EPO levels, total and differential WBC except lymphocytes in group S showed significant increased but lymphocyte was decreased compared to control group (p<0.05 to p<0.001). Dexamethasone, all concentrations of the extract and carvacrol treatment caused significantly improvement in all parameters compared to group S (p<0.05 to p<0.001). The effects of high concentration of the extract and carvacrol were higher compared to dexamethasone in most parameters (p<0.05 to 0.001). The effects of carvacrol on most parameter were higher than those of the extract (p<0.05 to 0.001). The effects of high concentration of the extract and carvacrol were significantly higher than those of their low concentration (p<0.05 to p<0.001). These results showed a preventive effect of the extract of Z. multiflora and its constituent carvacrol on lung inflammation of sensitized guinea pigs which was comparable or even higher than the effect of dexamethasone. The results also showed that the effect of the plant is perhaps due to its constituent carvacrol.