Determination of antioxidant activity of phenolic antioxidants in a Fenton-type reaction system by chemiluminescence assay

Abstract

The hydroxyl radical (*OH) has been implicated in various diseases, and it is therefore important to establish efficient methods to screen hydroxyl radical scavengers for antioxidant therapy. In this paper, a simple chemiluminescence assay was established to evaluate the *OH-scavenging capacity of phenolic compounds. This assay took advantage of the transient property of the Fenton reaction and the reaction between luminol and the hydroxyl radical, and effectively avoided the pro-oxidant action of some phenolic compounds. Fifteen phenolic compounds were assessed for their antioxidant activity in the Fenton reaction system, and even in the case of "pro-oxidants" that were excluded from the widely used deoxyribose (DR) assay. Since it overcomes the challenges that the traditional DR assay encounters, our method has promising applicative values: it is low-cost, time-saving, and reliable. It would also be more favorable than electron spin resonance (ESR) and radiolysis technology, which are known to be expensive and not commonly available to those specialized in free radical biology and medicine.

Review of Methods to Determine Antioxidant Capacities

“…Hantzsch reaction method and TBA method are simple and do not need expensive instruments; however, both of the reactions need high temperature (60-100°C) and long reaction time (30-60 min; Zou et al 2002). Moreover, the organic mobile phase of the HPLC assay, in which Á HO is generally detected by determining the dihydroxylated benzoic acid products derived from salicylic acid, will possibly cause environmental pollution and harm to health (Cheng et al 2003). Zhu et al (2000) reported a metal-independent organic Fenton reaction that production of HO Á by tetrachlorohydroquinone (a major metabolite of the widely used biocide pentachlorophenol) in the presence of H 2 O 2 was obtained.…”

“…The methods take advantage of the transient properties of the Fenton reaction and chemiluminescent reaction between Á OH and luminol. However, other ROS, including O Á À 2 and H 2 O 2 , are generated at the same time, so it is difficult to detect Á OH specifically with this detection process (Cheng et al 2003;Chen et al 2006).…”

Cosmetic applications of selected traditional Chinese herbal medicines

“…The hydroxyl radical was generated by the Fenton reaction using the luminescence method as modified by Cheng et al (2003). The reaction mixture contained 40 M luminol, 4.17 mM phosphate buffer (pH 7.5), 4.6 M iron(III)-2.3 M EDTA, test preparation, and 96 mM H 2 O 2.…”

Investigation on the interaction between dihydroxybenzene and Fe3+–H2O2–Rh6G system based on enhancing chemiluminescence

“…The acetonitrilehydrogen peroxide CL system has been proposed (15)(16)(17) for the determination of tetracycline and DNA. Polyphenols have been used to eliminate free radicals in physiological research (13). However, in this work, it was observed that polyphenols could enhance the weak CL reaction of hydroxyl radical and rhodamine 6G.…”