Protective effect of Blue-M1 against oxidative stress on COS-1 cells.

Blue-M1 is a blue pigment formed from xylose and glycine in the Maillard reaction. Previous work revealed that Blue-M1 scavenged hydroxyl radicals, and prevented the autoxidation of linoleic acid in vitro. We investigated the protective effect of Blue-M1 for 2,2'-azobis(2-amidino-propane)dihydrochloride (AAPH)-induced toxicity in COS-1 cells. COS-1 cells were cultured in AAPH containing DMEM medium with or without Blue-M1 at 37 degrees C for 24 h. Blue-M1 decreased the AAPH-induced toxicity in COS-1 cells, and this effect was dose-dependent. Furthermore, COS-1 cells were treated with diphenyl-1-pyrenylphosphine (DPPP), as a reagent for the detection of lipid peroxide, and then were cultured in AAPH containing DMEM medium with or without Blue-M1 at 37 degrees C for 6 h. Blue-M1 prevented the AAPH-induced peroxidation of cell membrane on COS-1 cells, and this effect was also dose-dependent. These results suggest that Blue-M1 prevents the oxidative cell injury. Therefore, Blue-M1 will be an antioxidant, which protect against the oxidative stress in living systems.