Inhibitory effect of metformin on oxidative damage of alveolar epithelial cells and its mechanism

LI Peng; OUYANG Yunping; CHEN Tao; ZHAO Bo; YANG Xiaojun

doi:10.3969/j.issn.1002-266X.2023.32.009

Abstract：Objective To observe the inhibitory effect of metformin on hydrogen peroxide(H2O2)-induced oxidative damage in human alveolar epithelial cells A549,and to explore the related mechanism based on epithelial-mesenchymal transition(EMT)and nuclear factor-κb(NF-κB)signaling pathway regulation.Methods A549 cells were cultured in vitro and divided into the control group,model group,metformin group,BAY 11-7082 group,inhibitor group,and activa-tor group.Cells in the control group were not treated,while cells in the model group,metformin group,BAY 11-7082 group,inhibitor group and activator group were stimulated with 400 μmol/L H2O2 for 24 h to construct the in vitro models of acute lung injury.Cells in the metformin group were divided into three concentration subgroups,which were given 2.5,5 and 10 mmol/L metformin,respectively.Cells in the BAY 11-7082 group were treated with 5 mmol/L BAY 11-7082.According to the results of cell viability detected by CCK-8,5 mmol/L was selected as the optimal concentration of metfor-min.After modeling,cells in the inhibitor group and activator group were given 5 mmol/L metformin,and then BAY 11-7082(5 μmol/L)and Prostratin(1 μmol/L)were added,respectively.All groups were treated for 24 h.Cell morphology was observed under inverted microscope.Malondialdehyde(MDA)and superoxide dismutase(SOD)in the supernatant of cell culture medium were detected by enzyme-linked immunosorbent assay.The cell migration rate was measured by cell Scratch test.Western blotting was used to detect EMT-related proteins and NF-κB signaling pathway-related proteins in cells.Results Compared with the control group,cell growth was inhibited,cell morphology was irregular,cell debris in-creased,MDA,cell mobility,N-cadherin,vimentin,fibronectin and p-NF-κB p65 protein levels increased,and SOD and E-cadherin levels decreased in the model group(all P<0.05).Compared with the model group,the growth inhibition ef-fect of the metformin group and BAY 11-7082 group was weaker,the cell morphology was normal,the cell debris was less,the levels of MDA,cell mobility,N-cadherin,vimentin,fibronectin and p-NF-κB p65 protein decreased,and the levels of SOD and E-cadherin increased.The changes of above indexes were more significant in the inhibitor group than in the met-formin group(all P<0.05).The changes of the above indexes in the activator group were opposite to those in the metformin group.Conclusions Metformin could inhibit H2O2-induced oxidative damage in A549 cells,which might be related to the inhibition of NF-κB signaling pathway and the inhibition of cell migration and EMT.