ABSTRACT
The number of people diagnosed with diabetes continues to increase, especially among younger populations. Apart from genetic predisposition and lifestyle, there is increasing scientific and public concern that environmental agents may also contribute to diabetes. Food contamination by chemical substances that originate from packaging materials, or are the result of chemical reactions during food processing, is generally recognized as a worldwide problem with potential health hazards. Phthalates, bisphenol A (BPA) and acrylamide (AA) have been the focus of attention in recent years, due to the numerous adverse health effects associated with their exposure. This paper summarizes the available data about the association between phthalates, BPA and AA exposure and diabetes. Although their mechanism of action has not been fully clarified, in vitro, in vivo and epidemiological studies have made significant progress toward identifying the potential roles of phthalates, BPA and AA in diabetes development and progression. These chemicals interfere with multiple signaling pathways involved in glucose and lipid homeostasis and can aggravate the symptoms of diabetes. Especially concerning are the effects of exposure during early stages and the gestational period. Well-designed prospective studies are needed in order to better establish prevention strategies against the harmful effects of these food contaminants.
ABSTRACT
PURPOSE: The aim of this study was to investigate whether the daily administration of α-lipoic acid (LA) during 4 weeks prevents the redox disturbance in red blood cells (RBC) described in diabetes METHODS: Multiple low-dose streptozotocin (STZ) diabetes was induced in rats by the administration of 40 mg/kg STZ intraperitoneally (i.p.) for 5 consecutive days. LA was applied at a dose of 10 mg/kg i.p. for 4 weeks, starting from the last day of STZ administration. RESULTS: The LA-treated diabetic rats exhibited a general systemic improvement, revealed as the near restoration of body weight and of essential biochemical parameters. The latter was displayed as decreased hyperglycemia, lower triglyceride levels and lower serum activities of alanine aminotransferases and aspartate aminotransferases that point to a general improvement of diabetes-linked organ "lesions". The LA-treated diabetic rats also exhibited significant alleviation of oxidative stress, manifested as decreased lipid peroxidation and lower glycation levels of serum proteins and hemoglobin, while the RBC exhibited increased activities of antioxidant enzymes and elevated levels of reduced glutathione. In RBC, this was accompanied by decreased post-translational glycosylation by O-bound ß-N-acetylglucosamine (O-GlcNAc) of the antioxidant enzymes superoxide dismutase and catalase and of heat shock proteins HSP70 and HSP90. CONCLUSION: LA through its powerful antioxidant activity preserves the structural and functional integrity of RBC in diabetes. The RBC can then assume a more efficient role as the first line of systemic defense against diabetic complications arising from oxidative stress-induced damage of other tissues and organs.
Subject(s)
Acetylglucosamine/metabolism , Erythrocytes/drug effects , HSP70 Heat-Shock Proteins/metabolism , HSP90 Heat-Shock Proteins/metabolism , Thioctic Acid/pharmacology , Animals , Antioxidants/pharmacology , Catalase/metabolism , Diabetes Mellitus, Experimental/drug therapy , Electrophoresis, Polyacrylamide Gel , Erythrocytes/metabolism , Glutathione/metabolism , HSP70 Heat-Shock Proteins/genetics , HSP90 Heat-Shock Proteins/genetics , Iron/blood , Lipid Peroxidation/drug effects , Male , Malondialdehyde/metabolism , Oxidation-Reduction , Oxidative Stress/drug effects , Rats , Rats, Wistar , Streptozocin/metabolism , Superoxide Dismutase/metabolismABSTRACT
Toxic action of crude oil on the living world and ecosystems in general is a global problem of both aquatic and terrestrial environments. Bearing in mind the possibility of biodegradation of this toxicant, the procedures of determining counts and activity of cultivable microorganisms, and especially of bacteria responsible for degradation processes, are of great significance. The aim of this work was to study the possibility of modifying some solid media by adding triphenyltetrazolium chloride reagent as an indicator of the dehydrogenase activity, to develop a simple screening method for a simultaneous assessment of the count and activity of cultivable hydrocarbon-oxidizing bacteria in the oil-contaminated environments. The modified method appeared to be rapid and very suitable for the intended purposes.
