Antioxidative effects of proteglycans of embryonic genesis in streptozotocin-induced diabetic rats

Abstract

It is well accepted that oxidative stress plays a significant role in the pathogenesis of diabetes mellitus. The objective of this study was to investigate the effect of proteoglycans of embryonic genesis (PEG) on concentrations and activity of prooxidative and antioxidative metalloproteins in streptozotocin (STZ)-induced diabetes in rats. Methods: Study groups were as follows: vehicle control group (Group 1), STZ-induced diabetes (55 mg/kg, intraperitoneal injection [Group 2]), STZ-induced diabetes with prophylactic injection of PEG (0.5 mg/kg intraperitonealy injected) 1 week prior to STZ injection (Group 3). The following prooxidative metalloproteins were studied: levels of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) isoforms (extracellular Nox [eNox]) in serum; erythrocyte membranes; and spleen cell membranes, nucleus and mitochondria, as well as serum levels of superoxide-producing lipoprotein (suprol); cytochrome (cyt) b 5 from cytosol of erythrocytes; and cyt c from spleen cell cytosol. The antioxidative metalloproteins, particularly superoxide dismutase and catalase from erythrocyte and from spleen cell cytosol were studied. Results: Results demonstrated the significant (P , 0.05) increase in the level and activity of NADPH-dependent, O 2 −-producing eNox activity in Group 2 in comparison with the control Group and decrease of the ferrihemoglobin-reducing activities of these Nox, as well as a significant increase in O 2 −-producing activity of suprol. In Group 2, there was a significant elevation of the level of cyt c, and decreased cyt b 5 level, as well as inhibition of superoxide dismutase and catalase activity. Conclusion: The prophylactic injection of the PEG demonstrated overall antioxidative effect, with prevention of changes in prooxidative markers.