n-BuOH extract of Bletilla striata exerts chemopreventive effects on lung against SiO2 nanoparticles through activation of Nrf2 pathway

SiO2 nanoparticles (nm SiO2) are ubiquitous in daily life and are acknowledged to be detrimental to human health. Bletilla striata is a traditional medicine used for generations in China and its polysaccharide has the anti-pulmonary fibrosis effect. To investigate the lung protective effect of the small molecules (n-BuOH extract) of B. striata and clarify the underlying mechanism. C57BL/6 mice were subjected to intratracheal instillation with nm...