Polysaccharide FMP-1 from Morchella esculenta attenuates cellular oxidative damage in human alveolar epithelial A549 cells through PI3K/AKT/Nrf2/HO-1 pathway

Oxidative stress is considered to involve cell death in severe pulmonary diseases like idiopathic pulmonary fibrosis (IPF). Polysaccharide FMP-1 from Morchella esculenta can exert significant antioxidant activity. However, its effects on alveolar epithelial cells remain unperceived. Herein, the effects of FMP-1 against H 2 O 2 -induced oxidative damage in human alveolar epithelial A549 cells were investigated. FMP-1 could inhibit H 2 O 2 -induced cytochrome C and Caspase-3 release to prevent cell apoptosis via attenuation of MDA and ROS levels, and enhancement the enzymatic activities of SOD and T-AOC. Furthermore, the underlying molecular mechanisms were clarified. The phosphorylation of AKT and the nuclear translocation of Nrf2 were observed to be promoted by FMP-1 as well as the level of HO-1. These findings suggested that FMP-1 attenuate cellular oxidative stress through PI3K/AKT pathway, and FMP-1 could be explored as natural potential antioxidants to lower oxidative stress relevant to the progression of IPF.