Taraxasterol, a pentacyclic-
triterpene isolated from Taraxacum officinale, has been demonstrated to have anti-inflammatory effects. However, the protective effects of
taraxasterol against cigarette
smoke (CS)-induced
lung inflammation have not been reported. This study aimed to investigate the protective effects and mechanism of
taraxasterol on CS-induced
lung inflammation in mice. CS-induced mouse
lung inflammation model was used to investigate the protective effects of
taraxasterol in vivo. Human bronchial epithelial cells (HBECs) were used to investigate the protective mechanism of
taraxasterol in vitro. The results showed that
taraxasterol attenuated CS-induced lung pathological changes, inflammatory cells infiltration, inflammatory
cytokines TNF-α,
IL-6 and IL-1β production.
Taraxasterol also up-regulated CS-induced
glutathione (GSH) production. In vitro,
taraxasterol was found to inhibit CS-induced
reactive oxygen species production, recruitment of TLR4 into
lipid rafts, NF-κB activation, and
IL-8 production. Furthermore, our results showed that
antioxidant N-acetyl-L-cysteine (NAC) significantly inhibited CS-induced recruitment of TLR4 into
lipid rafts as well as
IL-8 production. In conclusion, our results suggested that
taraxasterol had protective effects of CS-induced
lung inflammation.