A double-blind, randomized, placebo-controlled clinical trial on the effect of carvacrol on serum cytokine levels and pulmonary function tests in sulfur mustard induced lung injury.

Objective: The aim of this study was to evaluate the effect of carvacrol on serum levels of interleukins (IL-2, IL-4, IL-6, IL-8, and IL-10), interferon-gamma (IFNγ) levels and pulmonary function tests (PFT) in patients who were exposed to sulfur mustard (SM).

Methods: Twenty patients exposed to SM 27-30 years ago were divided to placebo and carvacrol (1.2 mg/kg/day) treated groups (n = 10 for each group). Drugs were given in a double-blind manner for two months. Serum levels of cytokines and PFT values including; maximum mid-expiratory flow (MMEF) and maximum expiratory flow at 25, 50 and 75% of vital capacity (MEF25, 50 and 75) were measured at the beginning (step 0), one and two month (steps I and II, respectively) after starting the treatment.

Results: The serum levels of IL-2, IL-4, IL-6 and IL-8 were significantly decreased in step I and II compared to step 0 (p < 0.05 to p < 0.001), while the serum levels of IL-10 and IFNγ were increased in step II compared to step 0 (p < 0.01, for both cases) and IFN-γ/IL-4 ratio was enhanced in step II compared to step 0 (p < 0.001) in carvacrol treated group. MMEF, MEF75, and 50 values were significant increase in step I and II compared to step 0 (p < 0.05 to p < 0.001) in carvacrol treated group.

Conclusion: Treatment with carvacrol for two months reduced inflammatory cytokine, while increased anti-inflammatory cytokines and improved PFT tests in SM induced lung injury.