Soyasaponin I alleviates inflammation and oxidative stress in chronic obstructive pulmonary disease through inhibiting the MAPK signaling pathway

Chronic obstructive pulmonary disease (COPD) is a prevalent lung disease that mainly induced by cigarette smoking (CS). Soyasaponin I is an amphiphilic oleanane triterpenoid glycoside extracted form Astragali Radix. In order to investigate treatment strategies of COPD, this study focused on the effect of soyasaponin I on the lung tissue of COPD model. The mouse model of COPD was induced by CS exposure for 12 weeks, and was administrated with different doses of soyasaponin I. Subsequently, the morphology and histopathology of lung tissue, the proportion of inflammatory cell, the levels of inflammatory cytokines, and indicators of oxidative stress were assessed and analyzed. The signaling pathway potentially regulated by soyasaponin I in the pathogenesis of COPD were predicted by network pharmacology analysis and validated by western blot. Our results demonstrated that soyasaponin I mitigated the lung injury and bronchial lesions induced by COPD through reducing the lung coefficient, wall area of the bronchioles and Periodic Acid Schiff (PAS)-positive cells in the lung tissue. The CS-induced inflammation and oxidative stress was alleviated by soyasaponin I through reversing the levels of inflammatory cytokines and oxidative stress indicators. In addition, the phosphorylation of p38, JNK and ERK1/2 was activated in COPD model, and was reverted by soyasaponin I in the lung tissue. Collectively, the present study confirmed that soyasaponin I is an effective compound that attenuates the lung injury through inhibiting inflammatory response and oxidative stress via the mitogen-activated protein kinase (MAPK) signaling pathway.