Systemic inflammation and oxidative stress induced by inhaled paraquat in rat improved by carvacrol, possible role of PPARγ receptors.

Control rats were exposed to saline aerosol, two groups were exposed to paraquat (PQ), 27 (PQ-L) and 54 (PQ-H) mg/m3 aerosols and six groups were treated with carvacrol, 20 (C-L) and 80 (C-H) mg/kg/day, pioglitazone, 5 (Pio-L) and 10 (Pio-H) mg/kg/day, C-L+Pio-L and dexamethasone, 0.03 mg/kg/day, for 16 days after the end of exposure to PQ-H. Different variables were measured after the end of treatment period. Total and differential white blood cells counts, nitrite, malondialdehyde, interleukin (IL)-10, and interferon-gamma levels were significant increased, but thiol, superoxide dismutase, catalase, IL-17, and tumor necrosis factor alpha were decreased in the blood due to both doses of PQ (p < 0.05-p < 0.001). Most measured parameters were significantly improved in treated groups with both doses of carvacrol, pioglitazone, the combination of C-L+Pio-L and dexamethasone compared to PQ-H group (p < 0.05-p < 0.001). Treatment with C-L+Pio-L showed significantly higher effects compared to each one alone (p < 0.05-p < 0.001). Systemic oxidative stress and inflammation due to inhaled PQ were improved by carvacrol and pioglitazone. Higher effects of C-L+Pio-L than each one alone suggests carvacrol modulating PPAR-γ receptors.