Untitled

Abstract

Previous investigation demonstrated the potential of L-cysteine (L-Cys) at high concentrations to cause hypoglycemia in mice totally deprived of insulin. For further elucidation of the glucose-lowering mechanism, glucose uptake and quantity of glucose transporters (GLUTs 3 and 4) in mouse soleus muscle and C2C12 muscle cells, as well as in human SH-SY5Y neuroblastoma cells, were investigated. A marked enhancement of glucose uptake was demonstrated, peaking at 5.0 mM L-Cys in soleus muscle (P < 0.05) and SH-SY5Y cells (P < 0.001), respectively. In contrast, glucose uptake was not affected in the C2C12 muscle cells. Kinetic analysis of the SH-SY5Y glucose uptake showed a 2.5-fold increase in maximum transport velocity compared with controls (P < 0.001). In addition, both GLUT3 and GLUT4 levels were increased following exposure to L-Cys. Our findings point to a possible hypoglycemic effect of L-Cys.

The Effect of Exogenous Free Nε-(Carboxymethyl)Lysine on Diabetic-Model Goto-Kakizaki Rats: Metabolomics Analysis in Serum and Urine

“…36 In addition, cysteine has an insulin-like action, promoting glucose entry into adipose cells through its free sulfhydryl group and protecting the function of pancreatic β-cells. 36,37 Recent studies have reported that the decreased cysteine level was associated with the altered oxidative stress level and insulin resistance, 38 which is consistent with our results. Aminomalonic acid is also a potent predictor of DM development, as indicated by studies.…”

Steviol Glycosides Modulate Glucose Transport in Different Cell Types

“…Translocation of GLUTs to the membrane has been reported as a consequence of various stimuli in many cellular types; in addition, changes in the expression of GLUTs have been described in response to several metabolic and oxidative stresses and in various physiological or pathological conditions. For example, insulin and ischemia induce GLUT1 movement to the membrane in rat heart [44]; doxorubicin recruits GLUT1 to the plasma membrane by a ROS-mediated mechanism in cardiomyocytes [37]; L-cysteine increases glucose uptake and GLUT3 levels in SH-SY5Y cells [45]; growth factors, cytokines, hydrogen peroxide, and cholesterol depletion are able to increase glucose uptake and GLUT1 translocation in leukaemia cell lines [46–49]. The expression of GLUT1 and GLUT4 in neuroblastoma and leukaemia cells following treatments with Stevia extracts or insulin was assessed by Western blot analysis on cell lysates.…”

Amino Acid Intakes Are Inversely Associated with Arterial Stiffness andCentral Blood Pressure in Women

“…A number of amino acids, including glutamic acid, arginine, glycine, cysteine, and histidine, have been shown to modulate concentrations of nitric oxide, a potent vasodilator ( 6 – 9 ). In addition, leucine has been shown to modulate insulin/phosphoinositide 3-kinase signaling in animal models ( 10 ), and cysteine has been shown to increase glucose uptake and concentrations of glucose transporter 3 and glucose transporter 4 in vitro; in rat models, dietary cysteine has been shown to reduce insulin resistance and glucose intolerance ( 11 , 12 ). Tyrosine is thought to reduce blood pressure by stimulating catecholamine synthesis in the brain ( 13 ), whereas histidine has been shown to inhibit vascular expression of the angiotensin converting enzyme mRNA in hypertensive rats ( 9 ).…”