OBJECTIVES

The effects of PPAR-γ agonist alone and in combination with carvacrol and on inhaled paraquat (PQ) induced-systemic inflammation and oxidative stress were examined.

MATERIALS AND METHODS

Control group exposed to normal saline aerosol, one group exposed to 54 mg/m PQ aerosol and four groups exposed to PQ aerosol and treated with 5 mg/kg/day pioglitazone, pioglitazone + 200 mg/kg/day Z. extract, pioglitazone + 20 mg/kg/day carvacrol, and 0.03 mg /kg/day dexamethasone for 16 days after the end of exposure to PQ were studied. Exposure to normal saline or PQ was performed every other days for 30 min (8 times). Different variables were measured after the end of treatment period.

RESULTS

PQ exposure significantly increased serum levels of NO, MDA and IL-6 but dexreased CAT and IFN-γ levels and IFN-γ/IL-6 ratio compared to control group (<0.01 to <0.001). Treatment with pioglitazone only improved serum level of MDA (<0.01). Treatment with combination of pioglitazone and carvacrol as well as treatment with dexamethasone improved all measured variables compared to PQ exposed group (<0.05 to <0.001). The effects of pioglitazone + Z. and pioglitazone + carvacrol on almost all measured variables were significantly higher than pioglitazone alone (<0.05 to <0.001).

CONCLUSION

The effects of combination therapy of pioglitazone with Z. or carvacrol on inhaled paraquat (PQ) induced-oxidative stress and systemic inflammation were higher than the effects of pioglitazone alone. These results suggested that the effects of the extract and carvacrol may mediated through PPAR-γ receptors.