Objective: The aim of this study was to compare in vivo effect of five pharmacological options on inflammation and pulmonary fibrosis induced by paraquat.

Methods: 54 Wistar SPF rats were used. After 2 h post-intoxication with paraquat ion, groups of 9 animals were randomly assigned to (1) cyclophosphamide plus dexamethasone (2) low molecular weight heparin (3) unfractionated heparin (4) vitamin C every 24 h, (5) atorvastatin or (6) placebo with intraperitoneal saline. Lung inflammation, alveolar injury, hepatocyte damage, hepatic regeneration, acute tubular necrosis and kidney congestion were evaluated.

Results: In the control group 100% of animals presented moderate and severe lung inflammation, while in the groups with atorvastatin and intratracheal heparin this proportion was lower (55.5%; CI 26.6-81.3%) (p = 0.025). A lower degree of moderate or severe hepatic regeneration was evident in the treatment groups with atorvastatin (p = 0.009). In this study was demonstrated that statins and heparin might have a protective effect in the paraquat-induced destructive phase. More evidence is needed to evaluated of dose-response effects of these drugs before to study in clinical trials.

Keywords: Inflammation; Lung; Paraquat.