Oxidative stress biomarkers and acetylcholinesterase activity in human erythrocytes exposed to clomazone (in vitro)

The aim of this study was to investigate the effect of clomazone herbicide on oxidative stress biomarkers and acetylcholinesterase activity in human erythrocytes in in vitro conditions. The activity of catalase (CAT), superoxide dismutase (SOD) and acetylcholinesterase (AChE), as well as the levels of thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) were measured in human erythrocytes exposed (in vitro) to clomazone at varying concentrations in the range of 0, 100, 250 and 500 µg/L for 1 h at 37 °C.TBARS levels were significantly higher in erythrocytes incubated with clomazone at 100, 250 and 500 µg/L. However, erythrocyte CAT and AChE activities were decreased at all concentrations tested. SOD activity was increased only at 100 µg/L of clomazone. GSH levels did not change with clomazone exposure. These results clearly showed clomazone to induce oxidative stress and AChE inhibition in human erythrocytes (in vitro). We, thus, suggest a possible role of ROS on toxicity mechanism induced by clomazone in humans

Effects of Polyphenol-Rich Chokeberry Juice on Antioxidant/Pro-Oxidant Status in Healthy Subjects

Berry fruits are a rich source of polyphenols, especially anthocyanins: well-known potent anti-oxidant phytochemicals. The purpose of this study was to evaluate beneficial effects of long-term consumption of polyphenol-rich organic chokeberry juice on different markers of antioxidant/pro-oxidant status in healthy female volunteers. Twenty-nine women, aged 25-49, were included in the study. Serological markers of oxidative stress and antioxidant defence, blood pressure, routine biochemical, and anthropometric parameters were analyzed at baseline and after twelve weeks of regular chokeberry juice consumption. Significant decrease in thiobarbituric acid-reactive substances level (TBARS; P lt .001) and pro-oxidant-antioxidant balance (PAB; P lt .05), as well as increase in paroxonase-1 activity toward diazoxon (P lt .01) were found. Total oxidative status and sulphydryl groups levels were not significantly influenced by the intervention. Anthropometric, biochemical parameters, and blood pressure values were within the referent values for all subjects and were not influenced by the chokeberry juice consumption. However, we found positive correlation between age, body mass index, waist circumference, body fat percent, blood pressure, and analyzed marker of lipid peroxidation, which was influenced by the consumption. In conclusion, the fine modulation of several antioxidant/pro-oxidant status biomarkers observed in healthy subjects indicates putative prophylactic effects of polyphenol-rich chokeberry juice and supports its importance as part of an optimal diet

Multivalent interacting glycodendrimer to prevent amyloid-peptide fibril formation induced by Cu(II): A multidisciplinary approach

Amyloid peptide fibrillogenesis induced by Cu(II) ions is a key event in the pathogenesis of Alzheimer’s disease. Dendrimers have been found to be active in preventing fibril formation. Therefore, they hold promise for the treatment of Alzheimer’s disease. In this study, the fibrillation mechanism of amyloid peptide Aβ 1-40 was studied by adding Cu(II) in the absence and presence of 4th generation poly(propyleneimine) glycodendrimer functionalized with sulfate groups, using dynamic light scattering (DLS), circular dichroism (CD), fluorescence, electron paramagnetic resonance (EPR) and molecular modeling (MD). The glycodendrimer was non-toxic to mHippoE-18 embryonic mouse hippocampal cells, selected as a nerve cell model, and decreased the toxicity of peptide aggregates formed after the addition of Cu(II). The binary systems of Cu(II)–glycodendrimer, Cu(II)–peptide, and glycodendrimer–peptide were first characterized. At the lowest Cu(II)/glycodendrimer molar ratios, Cu(II) was complexed by the internal-dendrimer nitrogen sites. After saturation of these sites, Cu(II) binding with sulfate groups occurred. Stable Cu(II)–peptide complexes formed within 5 min and were responsible for a transition from an α helix to a β-sheet conformation of Aβ 1-40. Glycodendrimer–peptide interactions provoked the stabilization of the α-helix, as demonstrated in the absence of Cu(II) by the Thioflavin T assay, and in the presence of Cu(II) by CD, EPR, and MD. Formation of fibrils is differentially modulated by glycodendrimer and Cu(II) concentrations for a fixed amount of Aβ 1-40. Therefore, this multidisciplinary study facilitated the recognition of optimal experimental conditions that allow the glycodendrimer to avoid the fibril formation induced by Cu(II). [Figure not available: see fulltext.]

Multivalent interacting glycodendrimer to prevent amyloid-peptide fibril formation induced by Cu(II): A multidisciplinary approach

Amyloid peptide fibrillogenesis induced by Cu(II) ions is a key event in the pathogenesis of Alzheimer’s disease. Dendrimers have been found to be active in preventing fibril formation. Therefore, they hold promise for the treatment of Alzheimer’s disease. In this study, the fibrillation mechanism of amyloid peptide Aβ 1-40 was studied by adding Cu(II) in the absence and presence of 4th generation poly(propyleneimine) glycodendrimer functionalized with sulfate groups, using dynamic light scattering (DLS), circular dichroism (CD), fluorescence, electron paramagnetic resonance (EPR) and molecular modeling (MD). The glycodendrimer was non-toxic to mHippoE-18 embryonic mouse hippocampal cells, selected as a nerve cell model, and decreased the toxicity of peptide aggregates formed after the addition of Cu(II). The binary systems of Cu(II)–glycodendrimer, Cu(II)–peptide, and glycodendrimer–peptide were first characterized. At the lowest Cu(II)/glycodendrimer molar ratios, Cu(II) was complexed by the internal-dendrimer nitrogen sites. After saturation of these sites, Cu(II) binding with sulfate groups occurred. Stable Cu(II)–peptide complexes formed within 5 min and were responsible for a transition from an α helix to a β-sheet conformation of Aβ 1-40. Glycodendrimer–peptide interactions provoked the stabilization of the α-helix, as demonstrated in the absence of Cu(II) by the Thioflavin T assay, and in the presence of Cu(II) by CD, EPR, and MD. Formation of fibrils is differentially modulated by glycodendrimer and Cu(II) concentrations for a fixed amount of Aβ 1-40. Therefore, this multidisciplinary study facilitated the recognition of optimal experimental conditions that allow the glycodendrimer to avoid the fibril formation induced by Cu(II)