Paraquat-induced systemic inflammation and oxidative stress in rats improved by Curcuma longa ethanolic extract, curcumin and a PPAR agonist.

The effect of Curcuma longa (Cl) ethanolic extract, nano-curcumin (Cu) and a PPARγ activator, pioglitazone on inhaled paraquat (PQ)-induced systemic inflammation and oxidative stress was examined in the present study. Control rats were exposed to normal saline and PQ groups to 27 and 54 mg/m3 (PQ-L and PQ-H) aerosols. Nine other PQ-H groups were treated with Curcuma longa (Cl, 150 and 600 mg/kg/day), nano-curcumin (Cu, 2 and 8 mg/kg/day), pioglitazone (Pio, 5 and 10 mg/kg), low dose of Pio + Cl and Cu and dexamethasone (0.03 mg/kg/day) for 16 days after PQ exposure period (n = 8). Total and differential WBC counts, malondialdehyde (MDA) and TNF-α levels were increased but thiol, catalase (CAT), superoxide dismutase (SOD), IL-10 and IFN-γ levels were decreased in the blood in the both PQ groups (p < 0.05 to p < 0.001). Treatment with Dexa and both doses of Cl, Cu, and Pio improved all measured variables compared to the PQ-H group (p < 0.05 to p < 0.001). The improvements of most variables in the treated group with low dose of Pio + Cl and Cu were higher than the effects of three agents alone. Systemic inflammation and oxidative stress induced by inhaled PQ were improved by Cl, Cu and Pio. In addition, a synergic effect between Pio with those of Cl and Cu was shown, suggesting PPARγ mediated effects of the plant and its derivative Cu.