Possible therapeutic effect of carvacrol on asthmatic patients: A randomized, double blind, placebo-controlled, Phase II clinical trial.

The relaxant effects of carvacrol, a phenolic monoterpene, on tracheal smooth muscle and its preventive effect on asthmatic animals were reported. The effect of carvacrol in asthmatic patients was examined in the placebo group (Group P, n = 11) receiving placebo and treatment group (Group C, n = 12), which received carvacrol capsule (1.2 mg/kg/day) for 2 months in a double-blind manner. Pulmonary function tests, respiratory symptoms, hematological indices, and high-sensitivity C-reactive protein (hs-CRP) were measured before, 1 and 2 months after starting treatment. At the end of treatment period, Pulmonary function tests values in Group C were significantly increased (p < .05 to p < .001). Most respiratory symptoms were also significantly reduced in Group C at the end of 2-month treatment (p < .05 to p < .001). Total and differential white blood cell (p < .05 to p < .001), as well as serum levels of hs-CRP in Group C were also significantly reduced after 2-month treatment with carvacrol (p < .001). Mean corpuscular hemoglobin concentration and hematocrit were changed in Group C (p < .05 and p < .01, respectively). However, in Group P, there was no significant changes in the evaluated parameters. Pulmonary function tests were increased but respiratory symptoms, inflammatory cells, and hs-CRP were reduced in asthmatic patients who received carvacrol that indicates its therapeutic effect on asthma.