ABSTRACT
Diabetic complications caused by hyperglycemia and oxidative stress, which can activate p38 mitogen-activatedprotein kinase (p38 MAPK), and aggravate complications via the enhancement of reactive oxygen species (ROS)generation. Recently, metformin or p38 MAPK inhibitors could reduce ROS production in particularly proteincarbonylation, in diabetic vessel. However, the combinatorial effect of metformin and SB203580 on internal organoxidative stress in non-obese (lean) type 2 diabetes mellitus (T2DM) is still uncleared. In this study, Goto-Kakizakirats were divided into four groups, including control diabetic group, metformin-treated group, p38 MAPK inhibitor(SB203580)-treated group, and combination between metformin and p38 MAPK inhibitor (SB203580). Internal organprotein from kidney, pancreas, liver, and brain was determined for protein carbonyl (PC) content by spectrophotometric2, 4-Dinitrophenylhydrazine assay. There was an increase in PC content levels in the serum and internal organs ofT2DM. Metformin ameliorated PC content in serum and internal organs. However, SB203580 could only reduce thePC content in the liver. The combination of metformin and SB203580 could synergistically reduce the PC contentlevels in serum but not the internal organs. In summary, metformin provided the greatest potential for reducingoxidative stress, while SB203580 or combined metformin with SB203580 could not reduce oxidative stress in theinternal organs of non-obese type 2 diabetic rats.