Scavenging effects of phenolic compounds on reactive oxygen species

Abstract

Phenolic compounds are widely present in plants and they have received considerable attention due to their antioxidant property. In this article we report the results of a study of the reactivity of 10 selected phenolics (sesamol, three phenolic acids, three flavonols, one flavone, and two flavanones) with superoxide anion radical (O(2) (*)), hydroxyl radical (HO(*)) and singlet oxygen ((1)O(2)). The following generators of reactive oxygen species were used: 18-crown-6/KO(2)/dimethylsulfoxide (DMSO) or hypoxanthine/xanthine oxidase as sources of O(2) (*), the Fenton reaction carried out in a sodium trifluoroacetate (pH 6.15) for HO(*), and a mixture of alkaline aqueous H(2)O(2) and cobalt ions for (1)O(2). We have employed chemiluminescence, electron spin resonance spin trapping, and spectrophotometry techniques to examine an antioxidative property. All tested compounds acted as scavengers of various reactive oxygen species. The reactivity indexes (beta) for the reaction of the phenolic compounds with HO(*) were calculated.

Protective effect of C. sativa leaf extract against UV mediated-DNA damage in a human keratinocyte cell line

“…This finding is in accordance with previous results that showed that this extract was able to scavenge 1 O 2 [11]. The phenolic compounds identified in ECS composition, namely phenolic acids (chlorogenic acid and ellagic acid) and flavonoids (rutin, isoquercitrin and hyperoside) have all been described as scavengers of reactive species [24][25][26][27] and thus their putative contribution to the free radical scavenging activity of the whole extract might be inferred. Noteworthy, the literature is rather scarce regarding their effect in the prevention of UV-induced DNA damage, with the exception of ellagic acid, mentioned above.…”

Development of spray‐ and freeze‐dried high‐concentration sesamol emulsions and antioxidant evaluation in fibroblasts and UV‐exposed rat skin slices

“…It was, therefore, concluded that DMPO-OOH inhibition by SEOH reflects its O 2 Á À scavenging effect. This property of SEOH was reported earlier [Kaur and Saini, 2000;Aboul-Enein et al, 2007] but in the latter study, no evidence was provided for the lack of any artifactual interaction between DMPO spin adducts and the phenolic group of SEOH.…”

“…In relation to a more general therapeutic purpose, the present studies were focused on developing stable sesamol-containing dry emulsions that retained high antioxidant properties. Sesamol (3,4-methylenedioxyphenol, SEOH) was selected as the active agent because of its known free radical scavenging [Joshi et al, 2005;Aboul-Enein et al, 2007] and anti-lipoperoxidant [Ghafoorunissa et al, 2004;Hsu et al, 2006] activities, and because it has demonstrated a great efficacy in simple ointment-based formulations for preventive topical application in the mouse exposed to phototoxic doses of UV light [Sharma and Kaur, 2006] or a protective ability after in vivo administration to g-irradiated mice [Parihar et al, 2006].…”

Evaluation of the Antioxidant Activity of the Marine Pyrroloiminoquinone Makaluvamines

“…The presence of hydroxyl groups attached to aromatic ring substructures contributes to antioxidant effects through hydrogen donation. Moreover, the presence of oxo groups, such as the ketonic C=O at position 8 in the makaluvamines, and the absence of the C10/C11 double bond contributed to improving the antioxidant characteristics [26,27]. …”