Protective Effect of Veratric Acid on Lipopolysaccharide-induced Acute Lung Injury in Mice

Veratric acid, a simple benzoic acid derived from plants and fruits, has been reported to exhibit antibacterial, anti-inflammatory and other important therapeutic activities. The aim of this study was to detect the effects of veratric acid on LPS-induced acute lung injury and to investigate the effects of veratric acid on NF-κB signaling pathway. Male BALB/c mice were pretreated with dexamethasone or veratric acid 1h before intranasal instillation of LPS. 7h after LPS administration, the myeloperoxidase in lung tissues, lung wet/dry weight ratio and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The effects of veratric acid on pro-inflammatory cytokines and signal pathways were analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blotting. The results showed that veratric acid inhibited LPS-induced TNF-α, IL-6 and IL-1β production in a dose dependent manner. It was also observed that veratric acid attenuated lung histopathologic changes. The wet/dry weight ratio of lungs and the number of total cells, neutrophils, macrophages in the BALF were all decreased. Furthermore, veratric acid inhibited the phosphorylation of NF-κB p65 and IκB. These results indicate that veratric acid inhibits NF-κB signaling pathways to attenuate inflammatory injury induced by LPS. Veratric acid may be a potential therapeutic reagent for acute lung injury treatment.