The effect of Zataria multiflora and carvacrol on wheezing, FEV1 and plasma levels of nitrite in asthmatic patients

Objective The preventive effect of Zataria multiflora in animal models of asthma has been reported. In the present study, its effect on wheezing, forced expiratory volume in 1 second, and plasma nitrite (NO2-) in asthmatic patients was studied. Materials and Methods In this study, forty asthmatic patients including 15 males and 25 females (aged 45.8±6.21 years) were randomly allocated in four groups including placebo group (P), and three treatment groups which received two doses of Z. multiflora (groups Z low and Z high that received 5 and 10 mg/kg/day, respectively) and carvacrol (group C treated with 1.2 mg/kg/day). All patients were treated for two months in a double-blind manner. At three time points (before starting the treatment (pretreatment), and one and two month after treatment), wheezing during day and exercise, forced expiratory volume in 1 second and NO2- were measured. Results Day wheeze and exercise wheeze were significantly reduced in treated groups with carvacrol and both doses of Z. multiflora compared to pretreatment (p<0.05 to p<0.01). However, FEV1% was significantly increased in treated groups with carvacrol and both doses of Z. multiflora (p<0.05 to p<0.001). Plasma level of NO2- was also significantly decreased in Z high and carvacrol groups after two months of treatment (p<0.01 to p<0.001). However, most of evaluated parameters in placebo group did not show significant changes during the study. Conclusion Z. multiflora and its constituent, carvacrol, improved FEV1% while reduced wheezing and plasma level of NO2- in asthmatic patients. Therefore, a possible therapeutic potential for this plant and its constituent, carvacrol could be suggested to be used against asthma.