Evaluation of the Biochemical Effects of Silyl-Phosphaalkenes on Oxidative and Nitrosative Stress Pathways Involving Metallocenters

Bischin, Cristina; Tusan, Camelia; Bartók, Ágota; Septelean, Raluca; Damian, Grigore; Silaghi-Dumitrescu, Radu

doi:10.1080/10426507.2014.884090

Cited by 5 publications

(13 citation statements)

References 18 publications

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“…In this context, it was suggested that the autocatalytic behavior might be relevant for acute in vivo poisoning, while at physiological nitrite concentrations there are antioxidant systems (small antioxidant molecules, proteins and enzymes) that might scavenge the propagator species [ 20 ]. Furthermore, hemoglobin’s free radical reactivity, in reactions related to these and where high-valent iron and free radicals are generated, is of more general analytical importance [ 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ]. In this context, experiments where small quantities of different antioxidant molecules were added to the nitrite + oxy reaction were also performed as detailed in the Supporting Information (Figure S25) .…”

Section: Resultsmentioning

confidence: 99%

The Reaction of Oxy Hemoglobin with Nitrite: Mechanism, Antioxidant-Modulated Effect, and Implications for Blood Substitute Evaluation

et al. 2018

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The autocatalytic reaction between nitrite and the oxy form of globins involves free radicals. For myoglobin (Mb), an initial binding of nitrite to the iron-coordinated oxygen molecule was proposed; the resulting ferrous-peroxynitrate species was not detected, but its decay product, the high-valent ferryl form, was demonstrated in stopped-flow experiments. Reported here are the stopped flow spectra recorded upon mixing oxy Hb (native, as well as chemically-derivatized in the form of several candidates of blood substitutes) with a supraphysiological concentration of nitrite. The data may be fitted to a simple kinetic model involving a transient met-aqua form, in contrast to the ferryl detected in the case of Mb in a similar reaction sequence. These data are in line with a previous observation of a transient accumulation of ferryl Hb under auto-catalytic conditions at much lower concentrations of nitrite (Grubina, R. et al. J. Biol. Chem. 2007, 282, 12916). The simple model for fitting the stopped-flow data leaves a small part of the absorbance changes unaccounted for, unless a fourth species is invoked displaying features similar to the oxy and tentatively assigned as ferrous-peroxynitrate. Density functional theory (DFT) calculations support this latter assignment. The reaction allows for differentiating between the reactivities of various chemically modified hemoglobins, including candidates for blood substitutes. Polymerization of hemoglobin slows the nitrite-induced oxidation, in sharp contrast to oxidative-stress type reactions which are generally accelerated, not inhibited. Sheep hemoglobin is found to be distinctly more resistant to reaction with nitrite compared to bovine Hb, at large nitrite concentrations (stopped-flow experiments directly observing the oxy + nitrite reaction) as well as under auto-catalytic conditions. Copolymerization of Hb with bovine serum albumin (BSA) using glutaraldehyde leads to a distinct increase of the lag time compared to native Hb as well as to any other form of derivatization examined in the present study. The Hb-BSA copolymer also displays a slower initial reaction with nitrite under stopped-flow conditions, compared to native Hb.

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Section: Resultsmentioning

confidence: 99%

The Reaction of Oxy Hemoglobin with Nitrite: Mechanism, Antioxidant-Modulated Effect, and Implications for Blood Substitute Evaluation

et al. 2018

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“…The enzymatic antioxidant assay (HAPX) measures the capability of the extract active compounds to quench the damage inflicted by hydrogen peroxide upon hemoglobin. Additional information is brought through this assay, since it implies the interaction between antioxidants molecules with a protein, the ferryl hemoglobin species (resulted by the action of hydrogen peroxide on ferric hemoglobin) [29,30].…”

Section: Resultsmentioning

confidence: 99%

“…According to Yang et al , the inhibition of lipid peroxidation increases with increasing concentrations of flavonoids [31]. Thus, the antioxidant capacity of the tested extracts, reflected in the delay of lipid oxidation, is considered to be based on the same mechanism found in HAPX: the interaction of antioxidants with ferryl, generated in this case in cytochrome c [30,32]. Through this assay both extracts demonstrated an antioxidant activity and a good correlation with DPPH and TEAC results (Figure 3).…”

Section: Resultsmentioning

confidence: 99%

“…The met forms of hemoglobin were prepared by ferricyanide treatment as previously described [37]. Liposomes were obtained by suspending 5 mg/mL soybean lecithin (Alfa Aesar) in phosphate buffer followed by sonication and horse heart purified cytochrome c from Sigma-Aldrich [30]. All spectrophotometric data were acquired using a Jasco V-530 UV-VIS spectrophotometer (Jasco International Co., Ltd., Tokyo, Japan).…”

Section: Methodsmentioning

confidence: 99%

“…The liposome oxidation experiment was performed at room temperature, for 600 min, in the presence of cytochrome c (2 µM) and extracts (5 µL from the diluted extract) by monitoring the absorbance at 235 nm (wavelength specific for liposome oxidation). This process monitors the formation of lipid conjugated dienes at the specified wavelength [30].…”

Section: Methodsmentioning

confidence: 99%

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Comparative Studies on Polyphenolic Composition, Antioxidant and Antimicrobial Activities of Schisandra chinensis Leaves and Fruits

et al. 2014

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The aim of this paper was to evaluate the antioxidant and antimicrobial activities and the polyphenolic content of Schisandra chinensis (Turcz.) Baill. leaves and fruits. The Qualitative and quantitative analyses of the polyphenolic compounds were achieved using a HPLC-UV-MS method. The main flavonoid from the leaves was isoquercitrin (2486.18 ± 5.72 μg/g plant material), followed by quercitrin (1645.14 ± 2.12 μg/g plant material). Regarding the fruit composition, the dominant compound there was rutin (13.02 ± 0.21 μg/g plant material), but comparing with the leaves, fruits can be considered a poor source of phenolic compounds. The antioxidant activity was evaluated by DPPH, TEAC, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c and EPR spectroscopic assays, revealing a better antioxidant activity for the S. chinensis leaves extract. In the antimicrobial assay, S. chinensis leaves extract showed efficient activities against the targeted bacteria, being more active than the fruits extract. The results suggest the leaves of S. chinensis as a valuable source of antioxidant compounds with significant antioxidant activity.

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On the Apparent Redox Reactivity of “Oxygen-Enriched Water”

Pușcaș

Moldovan

Silaghi-Dumitrescu

et al. 2020

Biol Trace Elem Res

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Evaluation of the Biochemical Effects of Silyl-Phosphaalkenes on Oxidative and Nitrosative Stress Pathways Involving Metallocenters

Cited by 5 publications

References 18 publications

The Reaction of Oxy Hemoglobin with Nitrite: Mechanism, Antioxidant-Modulated Effect, and Implications for Blood Substitute Evaluation

The Reaction of Oxy Hemoglobin with Nitrite: Mechanism, Antioxidant-Modulated Effect, and Implications for Blood Substitute Evaluation

Comparative Studies on Polyphenolic Composition, Antioxidant and Antimicrobial Activities of Schisandra chinensis Leaves and Fruits

On the Apparent Redox Reactivity of “Oxygen-Enriched Water”

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