Protective effects of thymol on LPS-induced acute lung injury in mice

Thymol, a naturally occurring phenol isolated from thyme, has been known to exhibit anti-inflammatory and anti-oxidative effects. The aim of this study was to determine the effect of thymol on acute lung injury (ALI) within an lipopolysaccharide (LPS)-induced mouse model. ELISA and western blotting were performed to detect the pro-inflammatory cytokines and signaling pathways. The myeloperoxidase (MPO) activity and MDA content in lung tissues, lung wet/dry (W/D) ratio and histopathological examination were detected. The results showed that thymol inhibit LPS-induced TNF-alpha, IL-6 and IL-1 beta production in BALF. Furthermore, thymol significantly reduced the MPO activity, MDA content, lung wet/dry weight ratio and histopathological changes induced by LPS. In addition, thymol inhibited LPS-induced NF-kappa B signaling pathway and up-regulated the expression of Nrf2 and HO-1. In conclusion, we found that thymol had anti-inflammatory and anti-oxidative effects against LPS-induced ALI and the mechanism was through suppressed NF-kappa B signaling pathway and activating Nrf2 signaling pathway.