Hydrogen peroxide, antioxidant compounds and biological targets: An in vitro approach for determination of scavenging capacity using fluorimetric multisyringe flow injection analysis

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Joana P N Ribeiro (Autor) Outra; Luis M Magalhaes (Autor) Outra; Marcela A Segundo (Autor) FFUP; Salette Reis (Autor) FFUP; Jose L F C Lima (Autor) FFUP

Revista

Título: Talanta

Vol. 81 Nº 1-2

Páginas: 1840-1846

ISSN: 0039-9140

Editora: Elsevier

Indexação

ISI Web of Knowledge - 2 Citações

Scopus - 3 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

CORDIS: Ciências da Saúde

Outras Informações

ID Authenticus: P-003-5QB

DOI: 10.1016/j.talanta.2010.03.049

Resumo (PT): In the present work, an automatic method based on multisyringe flow injection analysis (MSFIA) was developed for determination of scavenging capacity against H2O2 using a non-enzymatic fluorimetric assay for H2O2 detection based on the formation of europium-tetracycline-H2O2 complex. The MSFIA-fluorimetric methodology was developed to perform in-line the scavenging reaction of H2O2 prior to reaction of the remaining H2O2 with the fluorescent probe, using conditions close to those found in vivo regarding pH (6.9), temperature (37 °C) and H2O2 concentration (25 μM). This approach allowed the evaluation of scavenging capacity against H2O2 in a non-competitive (antioxidant + H2O2) or a competitive (antioxidant + H2O2 + biological target) scheme. Using the first strategy, IC50 values determined for the antioxidant compounds glutathione reduced (1191 ± 46 μM) and pyruvate (446 ± 49 μM) were lower than those obtained for biological targets such as cysteine (2616 ± 182 μM), taurine (359 ± 38 mM) and adenine (2224 ± 214 μM), indicating that reactivity towards H2O2 was higher for antioxidant compounds than for biological targets. However, when a competitive scheme was applied, the scavenging effectiveness against H2O2 depended on the biological molecule present, showing that antioxidant assessment should also take into consideration the concomitant reactivity of biological molecules or structures that are prone to oxidative damage. <br> <br> Keywords: Multisyringe flow injection analysis; Fluorimetry; Hydrogen peroxide; Antioxidant; Biological target <br> <a target="_blank" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THP-4YRHCMN-2&_user=2460038&_coverDate=06%2F15%2F2010&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=67a1d0e62e6fa611a89b206b97720ee7">Texto integral</a> <br> <br>

Abstract (EN): In the present work, an automatic method based on multisyringe flow injection analysis (MSFIA) was developed for determination of scavenging capacity against H(2)O(2) using a non-enzymatic fluorimetric assay for H(2)O(2) detection based on the formation of europium-tetracycline-H(2)O(2) complex The MSFIA-fluorimetric methodology was developed to perform in-line the scavenging reaction of H(2)O(2) prior to reaction of the remaining H(2)O(2) with the fluorescent probe, using conditions close to those found in vivo regarding pH (69), temperature (37 degrees C) and H(2)O(2) concentration (25 mu M) This approach allowed the evaluation of scavenging capacity against H(2)O(2) in a non-competitive (antioxidant + H(2)O(2)) or a competitive (antioxidant + H(2)O(2) + biological target) scheme. Using the first strategy. IC(50) values determined for the antioxidant compounds glutathione reduced (1191 +/- 46 mu M) and pyruvate (446 +/- 49 mu M) were lower than those obtained for biological targets such as cysteine (2616 +/- 182 mu M), taurine (359 +/- 38 mu M) and adenine (2224 +/- 214 mu). indicating that reactivity towards H(2)O(2) was higher for antioxidant compounds than for biological targets However, when a competitive scheme was applied, the scavenging effectiveness against H(2)O(2) depended on the biological molecule present, showing that antioxidant assessment should also take into consideration the concomitant reactivity of biological molecules or structures that are prone to oxidative damage.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7