Anti-inflammatory effect of thalidomide in paraquat-induced pulmonary injury in mice

Thalidomide has been used in inflammatory and autoimmune disorders due to its anti-inflammatory activity. Paraquat (PQ) poisoning causes severe lung injury. PQ-induced pulmonary inflammation and fibrosis are due to its ability to induce oxidative stress, inflammatory and fibrotic reactions. This study was designed to evaluate the anti-inflammatory and anti-fibrotic effect of thalidomide on PQ-induced lung damage in a mouse model. Mice were injected with a single dose of PQ (20 mg/kg, i.p.), and treated with thalidomide (25 and 50 mg/kg/day, i.p.) for six days. Lung tissues were dissected six days after PQ injection. The results showed that thalidomide ameliorated the biochemical and histological lung alterations induced by PQ. Thalidomide decreased production of inflammatory and fibrogenic cytokine tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and transforming growth factor (TGF)-β1. In addition thalidomide reduced myeloperoxidase (MPO), nitric oxide (NO), and hydroxyproline content in lung tissue. Taken together, the results of this study suggest that thalidomide might be a valuable therapeutic drug in preventing the progression of PQ-induced pulmonary injury.