Natural and natural-like polyphenol compounds: in vitro antioxidant activity and potential for therapeutic application

Abstract

IntroductionPhenols are a large family of natural and synthetic compounds with known antioxidant activity. The aim of this study was to preform an in vitro screening of natural and natural-like phenol monomers and their C2-symetric dimers (hydroxylated biphenyls) in order to identify those representatives which pharmacophores have the strongest antioxidant and the lowest prooxidant activity.Material and methodsAntioxidative properties of 36 compounds (monomers and their C2-symmetric dimers) were evaluated in vitro. Different (red/ox) assays were used to measure their total oxidative potential (TOP), their total antioxidative capacity (TAC), the pro-oxidative-antioxidant balance (PAB) and total SH-group content (SHG) in a biologically relevant environment. The Pro-oxidative Score, Antioxidative Score and the Oxy Score were also calculated. Trolox, a water soluble analogue of α-tocopherol was used as a positive control.ResultsIn an assay consisting of pooled human serum 6 of the 36 compounds indicated significant antioxidant activity (compounds 6, 7, 12, 13, 26, and 27) whereas 4 indicated extremely weak antioxidant activity (compounds 2, 29, 30, and 31). Within the 36 compounds comprising of zingerone, dehydrozingerone, aurone, chalcone, magnolol derivatives, in both monomeric and dimeric forms, the 2 compounds that indicated the highest antioxidant activity were dehydrozingerone derivatives (compounds 6 and 12). Trolox’s activity was found between the strong and weak antioxidant compounds analysed in our study.ConclusionsIn this study selected dehydrozingerones were identified as good candidates for in-depth testing of their biological behaviour and for possible precursors for the synthesis of novel polyphenolic molecules with potential therapeutic applications.