MTOR and pulmonary fibrosis: Cucurbiturin B inhibits pulmonary tissue EMT induced by TGF-β1 by regulating ROS and PI3K/AKT/mTOR pathway.[45] Astragaloside IV (AS-IV) is a natural saponin from Astragalus membranaceus, which shows anti-fibrotic properties in BLM-induced pulmonary fibrosis.