Lung inflammation changes and oxidative stress induced by cigarette smoke exposure in guinea pigs affected by Zataria multiflora and its constituent, carvacrol (BMC Complementary and Alternative Medicine)

Background: Chronic obstructive pulmonary disease (COPD) is an epidemic and progressive health problem which is mainly a consequence of cigarette smoking, and associated with lung inflammation. Anti-inflammatory property of Zataria multiflora (Z. multiflora) and its constituent, carvacrol was shown in various inflammatory disorders previously. Therefore, in the present study, the effects of the plant and its constituent, carvacrol, on lung inflammation changes and oxidative stress, in guinea pigs model of COPD were evaluated. Methods: Nine groups of animals including control, COPD, COPD + drinking water containing three concentrations of extract of Z. multiflora (0.4, 0.8, and 1.6 mg/mL), COPD + drinking water containing three concentrations of carvacrol (60, 120, and 240 μg/mL), and COPD + dexamethasone (50 μg/mL) were studied. For inducing COPD, animals were exposed to cigarette smoke for 3 months. Thiol groups, IL-8, total and differential WBC were measured in broncho-alveolar lavage fluid (BALF) (n = 6 for each group). Results: Total WBC, eosinophils, and neutrophils counts as well as the levels of IL-8 in BALF were significantly increased but thiol group was decreased in COPD compared to the control group (p