Figure 4.

Effects of NAC on ROS levels, SOD-1, GPX-1 and p-Akt/p-eNOS protein expression in HUVECs. (A) Intracellular ROS levels (magnification, ×100), and (B) protein expression levels of antioxidant enzymes (SOD-1 and GPX-1), p-Akt and p-eNOS in untreated HUVECs, or in HUVECs exposed to 1 mM MG, with or without NAC, or with NAC + BSO (glutathione inhibitor). Intracellular ROS levels were measured using 2′,7′-dichlorofluorescein diacetate. Protein expression levels were assessed by western blotting (n=4 repeats/group). *P<0.05 vs. control group; ^#P<0.05 vs. MG group; ^&P<0.05 vs. MG + NAC group. HUVECs, human umbilical vein endothelial cells; NAC, N-acetylcysteine; MG, methylglyoxal; BSO, buthionine sulfoximine; ROS, reactive oxygen species; SOD-1, superoxide dismutase 1; GPX-1, glutathione peroxidase 1; p-, phosphorylated; eNOS, endothelial nitric oxide synthase.