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-alpha 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.