SOD1 and diabetes mellitus: Immunohistochemical staining further confirmed: (1) SFN-treatment significantly increased the aortic SOD-1 expression in the control groups at both 3 months and 6 months; (2) Diabetes significantly increased at 3 months, and significantly decreased at 6 months, the aortic expression of SOD-1 protein; (3) Aortic expression of SOD-1 protein was significantly higher in DM/SFN mice than DM mice at both 3 months and 6 months of diabetes (Figure 7D).