SIRT1 and idiopathic pulmonary fibrosis: On the other hand, our previous study found that astragaloside IV (ASV), a bioactive saponin extract of the Astragalus root, could attenuate IPF by inhibiting TGF-β1-dependent EMT [19] and ASV was also reported to up-regulate sirt1 expression to inhibit glucose-induced EMT of podocytes [20].