Evaluation of Synergistic Antioxidant Potential of Complex Mixtures Using Oxygen Radical Absorbance Capacity (ORAC) and Electron Paramagnetic Resonance (EPR)

Abstract

Previous research has demonstrated that certain combinations of compounds result in a decrease in toxic or pro-oxidative effects, previously noted when compounds were administered singly. Thus, there is a need to study many complex interactions further. Two in vitro techniques [electron paramagnetic resonance (EPR) and oxygen radical absorbance capacity (ORAC) assays] were used in this study to assess pro- and antioxidant capacity and synergistic potential of various compounds. Rutin, p-coumaric acid, abscisic acid, ascorbic acid, and a sugar solution were evaluated individually at various concentrations and in all 26 possible combinations at concentrations found in certain foods (honey or papaya), both before and after simulated digestion. EPR results indicated sugar-containing combinations provided significantly higher antioxidant capacity; those combinations containing sugars and ascorbic acid demonstrated synergistic potential. The ORAC assay suggested additive effects, with some combinations having synergistic potential, although fewer combinations were significantly synergistic after digestion. Finally, ascorbic acid, caffeic acid, quercetin, and urate were evaluated at serum-achievable levels. EPR analysis did not demonstrate additive or synergistic potential, although ORAC analysis did, principally in combinations containing ascorbic acid.

Contributions of phenolics and added vitamin C to the antioxidant capacity of pomegranate and grape juices: synergism and antagonism among constituents

“…These findings are in agreement with our study that TAC assay and polyphenol composition both affect juice TAC interactions. A glucose, sucrose and fructose solution contributed to synergy between rutin and p‐ coumaric acid in the ORAC assay (Parker et al ., ), which conflicted with our finding that sugars and organic acids together interfered action of antioxidants in pomegranate‐nectarine and grape juices in TAC and total phenol assays. It is worth noting that we did not test the interaction using the sugar fraction alone in the study.…”

Optimization of the antioxidant and antimicrobial response of the combined effect of nisin and avocado byproducts

“…It is well known that members of the same group of polyphenols (phenolic acids, flavonols, flavone, etc.) do not have similar antioxidant activity despite having certain molecular similarity as this activity is a result of the environment and the presence of other compounds (Parker, Miller, Myers, Miguez, & Engeseth, 2010;Tabart, Kevers, Pincemail, Defraigne, & Dommes, 2009). It is likely that even though both extracts have similarities in composition, they do not have the same antioxidant capacity potentially due to the presence of unidentified compounds that could increase or have no effect on the antioxidant or antimicrobial activity observed in the extracts.…”

Synergistic Endo- and Exo-Interactions Between Blueberry Phenolic Compounds, Grape Variety Fractions, Chocolate Covered Strawberries, and Fruit Smoothies

“…2, No. 6;Parker et al (2010 reported that more complex combinations of antioxidants tended to show more synergy when measured by the ORAC assay. Our results in this study partially agreed with this.…”

“…The combination of acerola cherry extracts and alfalfa and soy phytoestrogen extracts worked to inhibit LDL oxidation synergistically in vitro (Hwang et al, 2001). Parker et al (2010) found synergistic interactions between mixtures of rutin, p-coumaric acid, abscisic acid, ascorbic acid, and a sugar mixture using oxygen radical absorbance capacity (ORAC) and electron paramagnetic resonance (EPR). Hidalgo et al (2010) discussed synergy between mixtures of two phenolic compounds, finding synergy in many of the combinations.…”