Effects of antioxidant stobadine on protein carbonylation,
advanced oxidation protein products and reductive capacity of liver in
streptozotocin-diabetic rats: Role of oxidative/nitrosative stress
Affiliations: Department of Medical Biochemistry, Faculty of
Medicine, Gazi University, Ankara, Turkey | Department of Experimental Pharmacology, Slovak
Academy of Science, Bratislava, Slovakia | Department of Pharmacology, Faculty of Pharmacy,
Ankara University, Ankara, Turkey | Department of Medical Pharmacology, Faculty of
Medicine, Gazi University, Ankara, Turkey
Note: [] Address for correspondence: Ç. Karasu, Department of Medical
Pharmacology, Faculty of Medicine, Gazi University, 06500 Ankara, Turkey.
E-mail: karasu@gazi.edu.tr
Abstract: Background: Increased oxidative/nitrosative stress is important in
the pathogenesis of diabetic complications, and the protective effects of
antioxidants are a topic of intense research. The purpose of this study was to
investigate whether a pyridoindole antioxidant stobadine (STB) have a
protective effect on tissue oxidative protein damage represented by the
parameters such as protein carbonylation (PC), protein thiol (P-SH), total
thiol (T-SH) and non-protein thiol (Np-SH), nitrotyrosine (3-NT), and advanced
oxidation protein products (AOPP) in streptozotocin-diabetic rats. Methods: Diabetes was induced in male Wistar rats by intraperitonal injection
of streptozotocin (55 mg/kg). Some of the non-diabetic (control) and diabetic
rats treated with STB (24.7 mg/kg/day) during 16 weeks, and the effects on
blood glucose, PC, AOPP, 3-NT, P-SH, T-SH and Np-SH were studied. Biomarkers
were assayed by enzyme-linked immunosorbent assay (ELISA) or by colorimetric
methods. Results: Administration of stobadine to diabetic animals lowered
elevated blood glucose levels by ∼ 16% relative to untreated diabetic
rats. Although stobadine decreased blood glucose, poor glycemic control was
maintained in stobadine treated diabetic rats during the treatment period.
Biochemical analyses of liver proteins showed significant diminution of
sulfhydryl groups, P-SH, T-SH, Np-SH, and elevation of carbonyl groups in
diabetic animals in comparison to healthy controls. As a biomarker of
nitrosative stress, 3-NT levels did not significantly change by diabetes
induction or by stobadine treatment when compared to control animals. However,
the treatment with stobadine resulted in a significant decrease in PC, AOPP
levels and normalized P-SH, T-SH, Np-SH groups in liver of diabetic
animals.
Journal: BioFactors, vol. 30, no. 3, pp. 171-178, 2007
