Oxidative DNA damage induced by HEPES (2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid) buffer in the presence of Au(III)

Habib, Ahsan; Tabata, Masaaki

doi:10.1016/j.jinorgbio.2004.07.005

Cited by 85 publications

(46 citation statements)

References 29 publications

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“…A direct potentiometric study provided the stability constants for ML type complexes of HEPES with several lanthanides [6]. An indirect evidence for at least transient Au(III) complexation to HEPES was provided by a very recent study of DNA damage in the presence these two agents, where HEPES acted as a reductant for Au(III) and provided stabilization for a radical species [7]. Similar phenomena were reported earlier for the Fe(II)/Fe(III) pair [8,9].…”

Section: Introductionsupporting

confidence: 66%

Cu(II) complexation by “non-coordinating” N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES buffer)☆

Sokołowska

Bal

2005

Journal of Inorganic Biochemistry

118

107

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Section: Introductionsupporting

confidence: 66%

Cu(II) complexation by “non-coordinating” N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES buffer)☆

Sokołowska

Bal

2005

Journal of Inorganic Biochemistry

118

107

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“…A recent report indicates that Au 3+ is cytotoxic to human K562 cells at concentrations >50 µM(Connor et al, 2005), but our results clearly indicate that phototoxicity of Au 3+ in Salmonella starts at a much lower concentration (1–5 µM range) and light irradiation enhances the toxicity. It has been reported that Au 3+ can oxidize HEPES or components of the Good’s buffer to nitrogen-centered free radicals and cause DNA strand cleavage with light irradiation (Habib and Tabata, 2004; Tabata, et al, 2005). Therefore, we believe that light irradiation of Au 3+ in solution may promote formation of free radicals that cause mutation in bacteria or even kill the bacteria.…”

Section: Discussionmentioning

confidence: 99%

Toxic effects of gold nanoparticles on Salmonella typhimurium bacteria

et al. 2011

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Nanometer-sized gold, due to its beautiful and bountiful color and unique optical properties, is a versatile material for many industrial and societal applications. We have studied the effect of gold nanoparticles on Salmonella typhimurium strain TA 102. The gold nanoparticles in solution prepared using the citrate reduction method is found not to be toxic or mutagenic but photomutagenic to the bacteria; however, careful control experiments indicate that the photomutagenicity is due to the co-existing citrate and Au3+ ions, not due to the gold nanoparticle itself. Au3+ is also found to be photomutagenic to the bacteria at concentrations lower than 1 µM, but toxic at higher concentrations. The toxicity of Au3+ is enhanced by light irradiation. The photomutagenicity of both citrate and Au3+ is likely due to the formation of free radicals, as a result of light-induced citrate decarboxylation or Au3+ oxidation of co-existing molecules. Both processes can generate free radicals that may cause DNA damage and mutation. Studies of the interaction of gold nanoparticles with the bacteria indicate that gold nanoparticles can be absorbed onto the bacteria surface but not able to penetrate the bacteria wall to enter the bacteria.

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“…The foundation for the model is that HEPES present in Tyrode buffer is known to spontaneously generate oxygen-centred radicals [18] that are detectable using the cell-permeable spin trap that is specific for oxygen-centred radicals (1-hydroxy-3-carboxy-pyrrolidine, CP-H; Axxora, Nottingham, UK). Briefly, whole blood was incubated (2 h; 37°C) with NAC (10-100 μmol/l) as described above, prior to preparation of washed platelets from the samples (washing removes extracellular NAC and facilitates introduction of radical-generating HEPES in Tyrode buffer).…”

Section: Methodsmentioning

confidence: 99%

Therapeutic potential of N-acetylcysteine as an antiplatelet agent in patients with type-2 diabetes

Gibson

Winterburn

Barrett

et al. 2011

Cardiovasc Diabetol

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BackgroundPlatelet hyperaggregability is a pro-thrombotic feature of type-2 diabetes, associated with low levels of the antioxidant glutathione (GSH). Clinical delivery of N-acetylcysteine (NAC), a biosynthetic precursor of GSH, may help redress a GSH shortfall in platelets, thereby reducing thrombotic risk in type-2 diabetes patients. We investigated the effect of NAC in vitro, at concentrations attainable with tolerable oral dosing, on platelet GSH concentrations and aggregation propensity in blood from patients with type-2 diabetes.MethodsBlood samples (n = 13) were incubated (2 h, 37°C) with NAC (10-100 micromolar) in vitro. Platelet aggregation in response to thrombin and ADP (whole blood aggregometry) was assessed, together with platelet GSH concentration (reduced and oxidized), antioxidant status, reactive oxygen species (ROS) generation, and plasma NOx (a surrogate measure of platelet-derived nitric oxide; NO).ResultsAt therapeutically relevant concentrations (10-100 micromolar), NAC increased intraplatelet GSH levels, enhanced the antioxidant effects of platelets, and reduced ROS generation in blood from type-2 diabetes patients. Critically, NAC inhibited thrombin- and ADP-induced platelet aggregation in vitro. Plasma NOx was enhanced by 30 micromolar NAC.ConclusionsOur results suggest that NAC reduces thrombotic propensity in type-2 diabetes patients by increasing platelet antioxidant status as a result of elevated GSH synthesis, thereby lowering platelet-derived ROS. This may increase bioavailability of protective NO in a narrow therapeutic range. Therefore, NAC might represent an alternative or additional therapy to aspirin that could reduce thrombotic risk in type-2 diabetes.

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Oxidative DNA damage induced by HEPES (2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid) buffer in the presence of Au(III)

Cited by 85 publications

References 29 publications

Cu(II) complexation by “non-coordinating” N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES buffer)☆

Cu(II) complexation by “non-coordinating” N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES buffer)☆

Toxic effects of gold nanoparticles on Salmonella typhimurium bacteria

Therapeutic potential of N-acetylcysteine as an antiplatelet agent in patients with type-2 diabetes

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