Iron-citrate complexes and free radicals generation: Is citric acid an innocent additive in foods and drinks?

Gautier‐Luneau, Isabelle; Bertet, Perrine; Jeunet, A.; Serratrice, Guy; Pierre, Jean‐Louis

doi:10.1007/s10534-006-9042-y

Cited by 27 publications

(29 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is noteworthy that the smaller AgNPs are capped with the lower molecular weight ligands with the carboxylate-to-alcohol ratio of 1, which, therefore, form, possibly via radical reactions [41,42], at early stages of the process, arresting the crystal growth ( Figure 5, b). The mechanisms need further study, but, anyway, the reactions are different from those in the solution bulk or living cell mitochondria, which proceed via the stages of oxidation of alcohol group to ketone as an intermediate, dehydration and decarboxylation [13,[26][27][28][29].…”

Section: Origin Of the Citrate-derived Ligandsmentioning

confidence: 99%

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

Mikhlin

Vorobyev

Сайкова

et al. 2018

Applied Surface Science

View full text Add to dashboard Cite

Citrate is an important stabilizing, reducing, and complexing reagent in the wet chemical synthesis of nanoparticles of silver and other metals, however, the exact nature of adsorbates, and its mechanism of action are still uncertain. Here, we applied X-ray photoelectron spectroscopy, soft X-ray absorption near-edge spectroscopy, and other techniques in order to determine the surface composition and to specify the citrate-related species at Ag nanoparticles 3 immobilized from the dense hydrosol prepared using room-temperature reduction of aqueous Ag + ions with ferrous ions and citrate as stabilizer (Carey Lea method). It was found that, contrary to the common view, the species adsorbed on the Ag nanoparticles are, in large part, products of citrate decomposition comprising an alcohol group and one or two carboxylate bound to the surface Ag, and minor unbound carboxylate group; these may also be mixtures of citrate with lower molecular weight anions. No ketone groups were specified, and very minor surface Ag(I) and Fe (mainly, ferric oxyhydroxides) species were detected. Moreover, the adsorbates were different at AgNPs having various size and shape. The relation between the capping and the particle growth, colloidal stability of the high-concentration sol and properties of AgNPs is briefly considered.

show abstract

Section: Origin Of the Citrate-derived Ligandsmentioning

confidence: 99%

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

Mikhlin

Vorobyev

Сайкова

et al. 2018

Applied Surface Science

View full text Add to dashboard Cite

show abstract

“…Citric acid is an important chemical that plays an important role in the physiological oxidation of glucose and other carbohydrates, as well as fats and proteins. The citric acid concentration controls several metabolite pathways and in higher organisms it regulates the utilization of calcium contained in foods (Gautier-luneau et al 2007). Ferric citrate (iron and citric acid) plays a paramount role in iron metabolism in living systems (Gautierluneau et al 2007).…”

Section: Discussionmentioning

confidence: 99%

“…Ferric citrate (iron and citric acid) plays a paramount role in iron metabolism in living systems (Gautierluneau et al 2007). Citrate is present in blood plasma in submillimolar concentration and promotes the bioavailability of dietary iron (Gautier-luneau et al 2007, Parkes et al 1991. Owing to fact that the mobilization of iron may lead to the formation of highly toxic hydrogen radicals Fontecave 1999, Gautier-luneau et al 2007), one can question concerning the innocence of adding citric acid in large amounts in foods or drinks (Gautier-luneau et al 2007).…”

Section: Discussionmentioning

confidence: 99%

“…Citrate is present in blood plasma in submillimolar concentration and promotes the bioavailability of dietary iron (Gautier-luneau et al 2007, Parkes et al 1991. Owing to fact that the mobilization of iron may lead to the formation of highly toxic hydrogen radicals Fontecave 1999, Gautier-luneau et al 2007), one can question concerning the innocence of adding citric acid in large amounts in foods or drinks (Gautier-luneau et al 2007). Gautier-luneau et al (2007) observed that iron:citrate and H 2 O 2 solution caused high amount of OH -radicals.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Clastogenic effects of food additive citric acid in human peripheral lymphocytes

et al. 2008

View full text Add to dashboard Cite

Clastogenic properties of the food additive citric acid, commonly used as an antioxidant, were analysed in human peripheral blood lymphocytes. Citric acid induced a significant increase of chromosomal aberrations (CAs) at all the concentrations and treatment periods tested. Citric acid significantly decreased mitotic index (MI) at 100 and 200 mug ml(-1) concentrations at 24 h, and in all concentrations at 48 h. However, it did not decrease the replication index (RI) significantly. Citric acid also significantly increased sister chromatid exchanges (SCEs) at 100 and 200 mug ml(-1) concentrations at 24 h, and in all concentrations at 48 h. This chemical significantly increased the micronuclei frequency (MN) compared to the negative control. It also decreased the cytokinesis-block proliferation index (CBPI), but this result was not statistically significant.

show abstract

“…Although the exact composition of the LIP is still a matter of controversy, iron can complex intracellularly with LMW chelates including ascorbate, citrate (39,40), small polypeptides, and lipid moieties (38). To date, the identity of the bioactive Fe-cit complex(es) remains unknown.…”

Section: Cxxgxxr[s/t]) Of All Ptps (4)mentioning

confidence: 99%

Protein Tyrosine Phosphatases Are Regulated by Mononuclear Iron Dicitrate

Gómez

Alisaraie

Shio

et al. 2010

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

The involvement of macrophages (Ms) as host, accessory, and effector cells in the development of infectious diseases, together with their central role in iron homeostasis, place these immune cells as key players in the interface between iron and infection. Having previously shown that the functional expression of NRAMP-1 results in increased protein phosphorylation mediated in part by an iron-dependent inhibition of M protein-tyrosine phosphatase (PTP) activity, we sought to study the mechanism(s) underlying this specific event. Herein we have identified the mononuclear dicitrate iron complex [Fe(cit) 2 H 4-x ] (1؉x)؊ as the species responsible for the specific inhibition of M PTP activity. By using biochemical and computational approaches, we show that [Fe(cit) 2 ] 5؊ targets the catalytic pocket of the PTP SHP-1, competitively inhibiting its interaction with an incoming phosphosubstrate. In vitro and in vivo inhibition of PTP activity by iron-citrate results in protein hyperphosphorylation and enhanced MAPK signaling in response to LPS stimulation. We propose that iron-citrate-mediated PTP inhibition represents a novel and biologically relevant regulatory mechanism of signal transduction.The balance of protein phosphorylation, maintained by the concerted action of protein kinases and protein phosphatases, is fundamental in determining the outcome of multiple cellular functions ranging from cell proliferation to cell death (1). In recent years the importance of protein tyrosine phosphatases (PTPs) 3 as coordinators of signaling pathways and the immune response has become evident (2). Progress has been achieved in understanding the mechanisms of PTP regulation, including receptor PTP dimerization (3), oxidation (4), and PTP phosphorylation. However, with more than 100 family members, a broad structural diversity, varying subcellular localizations and substrate specificities (5), the complexity of PTP activity regulation is far from being completely unraveled.Natural resistance-associated macrophage protein-1, NRAMP-1, is a divalent metal transporter localized to the late endosome/ lysosomal compartment of Ms (6), and present in gelatinase positive tertiary granules of neutrophils (7). Upon phagocytosis, NRAMP-1 is recruited to the phagolysosomal membrane where it mediates the export of Mn , and potentially other metals including Zn 2ϩ from the vesicle into the cytoplasmic compartment (8, 9). Functional NRAMP-1 expression has been linked to innate resistance to Leishmania donovani and other unrelated intracellular pathogens (10). In addition, it has been associated with the up-regulation of proinflammatory M functions such as MHC II expression (11), IL-1␤ (12), TNF-␣ (13), and NO production (14). We have recently reported that functional expression of NRAMP-1 results in lower M PTP activity and increased protein phosphorylation, in part explaining the pleiotropic effects of NRAMP-1 (15). Our findings suggest a model linking metal transport and the regulation of M functions: NRAMP-1 mediated iron transport directl...

show abstract

Iron-citrate complexes and free radicals generation: Is citric acid an innocent additive in foods and drinks?

Cited by 27 publications

References 13 publications

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

Clastogenic effects of food additive citric acid in human peripheral lymphocytes

Protein Tyrosine Phosphatases Are Regulated by Mononuclear Iron Dicitrate

Contact Info

Product

Resources

About