Automatic in vitro determination of hypochlorous acid scavenging capacity exploiting multisyringe flow injection analysis and chemiluminescence

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Luis M Magalhaes (Author) Other; Marcela A Segundo (Author) FFUP; Salette Reis (Author) FFUP; Jose L F C Lima (Author) FFUP; Jose Manuel Estela (Author) Other; Victor Cerda (Author) Other

Journal

Title: Analytical Chemistry

Vol. 79 No. 10

Pages: 3933-3939

ISSN: 0003-2700

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 29 Citations

ISI Web of Science

Scopus - 30 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-004-A36

DOI: 10.1021/ac0700068

Resumo (PT): In the present work, a chemiluminometric automatic flow methodology for the in vitro determination of hypochlorous acid scavenging capacity, under pH and concentration conditions similar to those found in vivo, is proposed. As the pH found in physiological conditions (7.4) and the pH required for the chemiluminescence detection reaction (>10) are different, the multisyringe flow injection analysis features were exploited to perform the in-line reaction of HOCl and the scavenger molecule at physiological pH prior to reaction of the remaining HOCl with luminol at alkaline conditions. These two reactions were carried out in about 3 s, allowing the determination of fast reacting antioxidants, in a time frame closer to in vivo generation of HOCl when compared to previously described methods. The developed method was applied to nonsteroidal antiinflammatory drugs of different chemical families, and positive controls (cysteine, gallic acid, lipoic acid). The HOCl scavenging capacity was evaluated at pH 7.4 and 10.0; different results were found for oxicam derivatives, providing evidence that the pH of in vitro methods should be carefully selected to allow assumptions about putative in vivo effects. <br> <br> <a target="_blank" href="http://pubs.acs.org/doi/abs/10.1021/ac0700068"> Texto integral</a> <br> <br>

Abstract (EN): In the present work, a chemiluminometric automatic flow methodology for the in vitro determination of hypochlorous acid scavenging capacity, under pH and concentration conditions similar to those found in vivo, is proposed. As the pH found in physiological conditions (7.4) and the pH required for the chemiluminescence detection reaction (> 10) are different, the multisyringe flow injection analysis features were exploited to perform the in-line reaction of HOCl and the scavenger molecule at physiological pH prior to reaction of the remaining HOCl with luminol at alkaline conditions. These two reactions were carried out in about 3 s, allowing the determination of fast reacting antioxidants, in a time frame closer to in vivo generation of HOCl when compared to previously described methods. The developed method was applied to nonsteroidal antiinflammatory drugs of different chemical families, and positive controls (cysteine, gallic acid, lipoic acid). The HOCl scavenging capacity was evaluated at pH 7.4 and 10.0; different results were found for oxicam derivatives, providing evidence that the pH of in vitro methods should be carefully selected to allow assumptions about putative in vivo effects.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7