Protective effect of L-cysteine on biomarkers and peripheral nervous system in streptozotocin-induced diabetic rats

Abstract

Abstract The present study investigated the protective effect of L-cysteine on biomarkers and peripheral nervous system in streptozotocin-induced diabetic rats. The experimental groups included sham, control, 0.1 mM cysteine treatment, and 0.2 mM cysteine treatment. Behavioral assessment, fasting glucose, lipid peroxidation, glutathione peroxidase, superoxide dismutase, and catalase activities, as well as reduced GSH, tumor necrosis factor (TNF), -α, interleukin-6 (IL-6), interleukin 1 beta (IL-1β), matrix metalloproteinase (MMP)-2, and MMP-9 levels were determined. Both mRNA and protein expression of MMP-2 and MMP-9 were assessed. L-Cysteine increased paw withdrawal threshold and latency to rat paw withdrawal. Fasting glucose, lipid peroxidation was reduced, while antioxidant markers returned to normal levels. TNF-α, IL-6, MMP-2/9 were also reduced following treatment. Treatment of rats with L-cysteine reduced MMP-2/9 mRNA and protein levels by more than 40%. Taken together, our findings show that L-cysteine supplementation is effective against biomarkers and peripheral neuropathy in a streptozotocin-induced diabetic rat model.