Effect of Buyang Huanwutang on Keap1/Nrf2/HO-1 Antioxidant Signaling Pathway in Rats with Idiopathic Pulmonary Fibrosis / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo study the effect of Buyang Huanwutang on Kelch-like Ech-related protein 1 （Keap1）/nuclear factor E2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） antioxidant signaling pathway in rats with idiopathic pulmonary fibrosis （IPF） and explore the mechanism of this prescription in the treatment of IPF. MethodForty SPF-grade male SD rats were assigned into a sham operation group， a model group， a Buyang Huanwutang group， and a nintedanib group according to random number table method， with 10 rats in each group. IPF rat model was established by intratracheal infusion of bleomycin （0.005 g·kg-1） in other groups except the sham operation group. Buyang Huanwutang group was administrated with Buyang Huanwutang (14.84 g·kg-1)，intragastric administration of nitedanib suspension (0.1 g·kg-1)，sham operation group and model group were given equal volume of normal saline， for 28 days. After lung function test， serum and lung tissue samples were collected. Hematoxylin-eosin （HE） staining and Masson trichrome staining were employed to observe the pathological changes of the lung tissue. The content of hydroxyproline （HYP） in lung tissue was detected. The levels of malondialdehyde （MDA） in serum and lung tissue， and the activities of superoxide dismutase （SOD）， glutathione peroxidase （GSH-Px） and catalase （CAT） were determined. The mRNA and protein levels of Keap1， Nrf2， and HO-1 was determined by Real-time fluorescent quantitative polymerase chain reaction， immunohistochemical staining， and Western blot. ResultCompared with the sham operation group， the modeling increased the resistance and elasticity and decreased the compliance of respiratory system （P<0.01）， elevated the lung index， pathological score， and HYP content in lung tissue （P<0.01）， and enriched MDA in serum and lung tissue， while it decreased the activities of SOD， GSH-Px， and CAT （P<0.01）. Furthermore， the modeling down-regulated the mRNA and protein levels of Keap1 and up-regulated those of Nrf2 and HO-1 in lung tissue （P<0.01）. Compared with the model group， Buyang Huanwutang decreased the resistance and elasticity and increased the compliance of respiratory system （P<0.01）， lowered the lung index， pathological score， and HYP content in lung tissue （P<0.01）， and reduced MDA in serum and lung tissue， while it increased the activities of SOD， GSH-Px， and CAT （P<0.01）. Additionally， Buyang Huanwutang down-regulated the expression of Keap1 and up-regulated that of Nrf2 and HO-1 in lung tissue （P<0.05， P<0.01）. ConclusionBuyang Huanwutang can activate Keap1/Nrf2/HO-1 signaling pathway to enhance the antioxidant capacity and slow down the pathological process of IPF in rats.