Abstract

Ethnopharmacological relevance Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with unknown etiology. Oxytropis falcata Bunge ( O. falcata ) is a 1–35 cm high perennial clustered herb, also known as edaxia, has viscosity and a special smell, and is mainly distributed in the western areas of China. The root of O. falcata has a diameter of 6 mm, is straight and deep, dark red and its stems are shortened, woody and multibranched. O. falcata has heat-clearing, detoxification, analgesic, anti-inflammatory, antibacterial, hemostatic and antitumor activities . Furthermore, O. falcata has excellent anti-inflammatory and analgesic effects, and it is one of the three major anti-inflammatory drugs in Tibetan medicine, known as “the king of herbs”. Total flavonoids of Oxytropis falcata Bunge (FOFB) were previously extracted, and their pharmacological activities are consistent with those of the whole herb. In this study, FOFB was extracted from O. falcata by ethanol extraction, and the mechanism of FOFB on IPF was verified by in vivo and in vitro experiments. Aim of the study In this study, we aimed to observe the effects of FOFB on idiopathic pulmonary fibrosis . Materials and methods In in vivo experiments, an IPF rat model was established by bleomycin induction. The rats were treated with FOFB (100, 200, 400 mg kg −1 ·d −1 ) for 4 weeks. Masson staining and the expression of TGF-β, p-Smad2, p-Smad3 and Smad7 in the lung tissue of rats were detected. In in vitro experiments, we perfused normal rats with FOFB (100, 200, 400 mg kg −1 ·d −1 ) and obtained the corresponding drug-containing serum. The HFL-1 cell model induced by TGF-β1 was used to detect the corresponding indices through intervention with drug-containing serum. The best intervention time for drug-containing serum was detected by the CCK-8 method. Changes in apoptosis , cytoskeleton and rough endoplasmic reticulum structure were detected. Finally, the expression of TGF