Five Cysteine-Containing Compounds Delay Diabetic Deterioration in Balb/cA Mice

The effects of n-acetyl cysteine (NAC), s-allyl cysteine (SAC), s-ethyl cysteine, s-methyl cysteine and s-propyl cysteine (SPC) activity on Balb/cA mice against diabetic complications were examined. These complications included hyperglycemia, hyperlipidemia, oxidation stress, blood coagulation, and cytokine imbalance. To induce diabetes, mice were treated with streptozotocin i.p. for 5 consecutive days. Five cysteine-containing compounds at 1 g/L were added to the drinking water. After intake of the 5 cysteine-containing agents for 4 wk, body weight loss, plasma concentrations of glucose and insulin, and fibronectin levels were improved (P < 0.05) in diabetic mice. The administration of these agents restored the glutathione level (P < 0.05), reduced the loss of catalase and glutathione peroxidase activities in kidney and liver (P < 0.05), and decreased glucose-induced lipid oxidation, as assessed by malondialdehyde formation (P < 0.05). In all diabetic mice, the intake of these agents reduced triglyceride levels in plasma and liver (P < 0.05); however, only NAC, SAC and SPC treatments reduced cholesterol level in liver (P < 0.05). These cysteine-containing agents elevated the activity of 2 fibrinolytic factors, protein C and antithrombin III (P < 0.05). The overexpression of interleukin-6 and tumor necrosis factor-α in diabetic mice was suppressed by the intake of the 5 cysteine-containing agents (P < 0.05). Via their antioxidant activities, the 5 compounds effectively improved glycemic control, delayed oxidation damage, downregulated inflammatory cytokines, and enhanced anticoagulant activity in diabetic mice. These data support the multiple roles of these agents as potential protective agents for delaying diabetic deterioration.