Publications by authors named "Nikolaos T Panagopoulos"

The study presents a new method that detects O, via quantification of 2-hydroxyethidium (2-ΟΗ-Ε) as low as ∼30 fmoles by High-Performance Thin Layer Chromatography (HPTLC). The method isolates 2-ΟΗ-Ε after its extraction by the anionic detergent SDS (at 18-fold higher than its CMC) together with certain organic/inorganic reagents, and its HPTLC-separation from di-ethidium (di-Ε) and ethidium (Ε). Quantification of 2-OH-E is based on its ex/em maxima at 290/540 nm, and of di-E and E at 295/545 nm.

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The aim of the present study was to investigate the effect of rutin administration (100 mg/kg/day) to pentylenetetrazol (PTZ)-treated Balb-c mice (60 mg/kg/day), with respect to anxiety-like behavior using both open-field and elevated plus-maze (EPM) tests, and acetylcholinesterase (AChE) activity in salt-soluble (SS) fraction and detergent-soluble (DS) fraction of the cerebral cortex, hippocampus, striatum, midbrain, and diencephalon. Our results demonstrated that the administration of PTZ in 3 doses and the induction of seizures increased significantly anxiety behavior of mice and reduced significantly DS-AChE activity in all brain regions examined, while the reduction in the SS fraction was brain region-specific. Rutin administration to normal mice did not affect their behavior, while it induced a brain region-specific reduction in SS-AChE and a significant decrease in DS-AChE in all brain regions.

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Neurotrophic factors are among the most promising treatments aiming at slowing or stopping and even reversing Parkinson's disease (PD). However, in most cases, they cannot readily cross the human blood-brain-barrier (BBB). Herein, we propose as a therapeutic for PD the small molecule 17-beta-spiro-[5-androsten-17,2'-oxiran]-3beta-ol (BNN-20), a synthetic analogue of DHEA, which crosses the BBB and is deprived of endocrine side-effects.

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Purpose: In the present study, we examined the effects of pentylenetetrazol (PTZ) administration on the thiol redox state (TRS), lipid peroxidation, and protein oxidation in the mouse striatum to (a) quantitate the major components of TRS and relate them to oxidative stress, and (b) investigate whether neuronal activation without synchronization, induced by subconvulsive doses of PTZ, can cause similar qualitative effects on TRS in this brain area. Specifically, we examined the TRS components glutathione (GSH), glutathione disulfide (GSSG), cysteine (CSH), protein thiols (PSH), and the protein (P) and nonprotein (NP/R) disulfides PSSR, NPSSR, NPSSC, and PSSP.

Methods: TRS components were measured photometrically (GSSG enzymatically) as were lipid peroxidation and protein oxidation.

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In this study we measured thiol redox state (TRS) and the oxidative stress indicator lipid peroxidation in midbrain and striatum of adult (4 months old) male control (+/+) and weaver (wv/wv) mice in order to relate them with oxidative stress in conditions of progressive and severe (approximately 70%) nigrostriatal dopaminergic neurodegeneration. Specifically, we measured the specific TRS components glutathione (GSH), glutathione disulfide (GSSG), cysteine (CSH), and the general classes of TRS components. The latter are the protein thiols (PSH) and the disulfides between (a) protein (P) and protein thiols (PSSP), (b) protein and non-protein (NP/R) thiols (PSSR, PSSC) and (c) non-protein and non-protein thiols (NPSSR, NPSSC).

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In the present study we examined the effects of pentylenetetrazol (PTZ) administration on the thiol redox state (TRS), lipid peroxidation and protein oxidation in left and right mouse cerebral cortex in order (a) to quantitate the major components of the thiol redox state and relate them with oxidative stress and cortical laterality, and (b) to investigate whether neuronal activation without synchronization, induced by subconvulsive doses of PTZ, can cause similar qualitative effects on the thiol redox state. Specifically, we examined the TRS components [glutathione (GSH), glutathione disulfide (GSSG), cysteine (CSH), protein (P) thiols (PSH) and protein and non-protein (NP) mixed/symmetric disulfides (PSSR, NPSSR, NPSSC, PSSP)]. At 15 min after seizure, GSH, GSSG, CSH, NPSSC, PSSR and PSSC levels are decreased in left (14-50%) and right (11-53%) cortex while PSSP levels are increased in both left (1400%) and right (1600%) cortex.

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In this study we evaluated oxidative stress (lipid peroxidation and protein oxidation) and thiol redox state [TRS: glutathione (GSH), glutathione disulfide (GSSG), cysteine (CSH), protein (P) thiols (PSH) and protein and non-protein (NP) mixed/symmetric disulfides (PSSR, NPSSR, NPSSC, PSSP)] in hippocampus after pentylenetetrazol (PTZ) administration at convulsive and subconvulsive dose. The significant decrease in PSH, CSH and NPSSC, as well as the increase in PSSP, NPSSR, lipid peroxidation and protein oxidation levels after PTZ-induced seizure indicate increased oxidative damage in hippocampus, although the levels of GSH and GSSG do not change significantly.

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