Open AccessHypochlorite scavenging activity of hydroxycinnamic acids evaluated by a rapid microplate method based on the measurement of chloramines
Author(s) -
Firuzi Omidreza,
Giansanti Luisa,
Vento Roberta,
Seibert Cathrin,
Petrucci Rita,
Marrosu Giancarlo,
Agostino Roberta,
Saso Luciano
Publication year - 2003
Publication title -
journal of pharmacy and pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 118
eISSN - 2042-7158
pISSN - 0022-3573
DOI - 10.1211/0022357021314
Subject(s) - chemistry , caffeic acid , ferulic acid , chloramine , chlorogenic acid , hypochlorite , chromatography , coumaric acid , hydroxycinnamic acid , phenolic acid , organic chemistry , biochemistry , antioxidant , chlorine
ABSTRACT Scavengers of hypochlorite (XOCI) could have beneficial effects in diseases in which this oxidant plays a pathogenic role. It has been reported that ferulic acid and chlorogenic acid, the quinic ester of caffeic acid, are good hypochlorite scavengers, but a systematic evaluation of the naturally occurring hydroxycinnamic acids (HCAs), which these substances belong to, has not been performed yet. Thus, in this work we studied, by two different in‐vitro methods, the antioxidant activity of five HCAs: p ‐coumaric acid, ferulic acid, sinapinic acid, caffeic acid and chlorogenic acid. The methods applied in this study were based on the oxidation of human serum albumin (HSA) by XOCI, a new microplate method based on the measurement of chloramines and a previously described carbonyl assay. Firstly, lysine‐derived chloramines, in the presence or absence of the HCAs, were detected using 5‐thio‐2‐nitrobenzoic acid (TNB), measuring the absorbance at 415nm by a microplate reader. To remove excess XOCI, Trolox, a known XOCI scavenger, was added before TNB. Secondly, lysine‐derived carbonyls, in the presence or absence of the HCAs, were detected by using 2,4‐dinitro‐phenylhydrazine. Hydroxycinnamic acids appeared active (caffeic≥sinapinic>chlorogenic≅ferulic> p ‐coumaric acid) by both methods, suggesting possible pharmacological applications for these compounds, which are present at high concentrations in the plant kingdom.