Evaluation of the protective effect of Curcuma longa and PPARγ agonist, pioglitazone on paraquat-induced lung injury in rats

Background

The inhalation of paraquat (PQ), one of the most widely used herbicides in the world, can result in lung injury. Curcuma longa (Cl) has long history in traditional and folk medicine for the treatment of a wide range of disorders including respiratory diseases.

Aim

The aim of the present work was to evaluate the preventive effect of Cl on inhaled PQ-induced lung injury in rats.

Methods

Male Wistar rats were divided into 8 groups (n = 7), one group exposed to saline (control) and other groups exposed to PQ aerosol. Saline (PQ), Cl extract, (two doses), curcumin (Cu), pioglitazone (Pio), and the combination of Cl-L + Pio and dexamethasone (Dex) were administered during the exposure period to PQ. Total and differential white blood cell (WBC) counts, oxidant and antioxidant indicators in the bronchoalveolar lavage (BALF), interleukin (IL)-10, and tumor necrosis alpha (TNF-α) levels in the lung tissues, lung histologic lesions score, and air way responsiveness to methacholine were evaluated.

Results

WBC counts (Total and differential), malondialdehyde level, tracheal responsiveness (TR), IL-10, TNF-α and histopathological changes of the lung were markedly elevated but total thiol content and the activities of catalase and superoxide dismutase were decreased in the BALF in the PQ group. Both doses of Cl, Cu, Pio, Cl-L + Pio, and Dex markedly improved all measured variables in comparison with the PQ group.

Conclusion

CI, Pio, and Cl-L + Pio improved PQ-induced lung inflammation and oxidative damage comparable with the effects of Dex.