BACKGROUND: This study was designed to evaluate the effects of carvacrol (CRV) and pomegranate extract (PE) on methotrexate (MTX)-induced lung injury in rats.

MATERIAL AND METHODS: A total of 32 male rats were subdivided into 4 groups: control (group I), MTX treated (group II), MTX+CRV treated (group III), and MTX+PE treated (group IV). A single dose of 73 mg/kg CRV was administered intraperitoneally to rats in group III on Day 1 of the investigation. To group IV, a dose of 225 mg/kg of PE was administered via orogastric gavage once daily over 7 days. A single dose of 20 mg/kg of MTX was given intraperitoneally to groups II, III, and IV on Day 2. The total duration of experiment was 8 days. Malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) were measured from rat lung tissues and cardiac blood samples.

RESULTS: Serum and lung specimen analyses demonstrated that MDA, TOS, and OSI levels were significantly greater in group II relative to controls. Conversely, the TAC level was significantly reduced in group II when compared to the control group. Pre-administering either CRV or PE was associated with decreased MDA, TOS, and OSI levels and increased TAC levels compared to rats treated with MTX alone. Histopathological examination revealed that lung injury was less severe in group III and IV relative to group II.

CONCLUSIONS: MTX treatment results in rat lung oxidative damage that is partially counteracted by pretreatment with either CRV or PE.

Keywords: Lung Injury - drug therapy, Methotrexate - adverse effects, Monoterpenes - therapeutic use, Oxidation-Reduction, Plant Extracts - therapeutic use, Punicaceae - chemistry, Rats, Wistar