Stigma maydis polysaccharides protect podocyte injury by reducing oxidative stress and apoptosis

Membranous nephropathy (MN) is a glomerulonephritis that has an C5b-9-mediated podocyte injury as its main feature. Stigma maydis polysaccharides (SMP) demonstrate a protective role against podocyte injury in vivo. However, their in vitro effects remain unknown. The aim of the present study was to verify the potential protective effect of acidic SMP (ASMP) and neutral SMP (NSMP) on podocytes in vitro. Morphological changes and cell migration were examined by inverted microscope, changes in reactive oxygen species level and apoptosis were detected by fluorescence microscope, while the cell cycle arrest were measured by flow cytometry. The expression of the phosphoinositide 3-kinases (PI3K), and Akt protein were detected by Western blot technique. This study showed that oxidative stress, migration, cell cycle arrest, and apoptosis were all significantly suppressed following pretreatment with either of the SMP, however ASMP showed greater effects overall. In conclusion, ASMP could potentially be developed as a functional food to protect podocytes from sC5b-9-induced oxidative stress and apoptosis injury.