Antioxidant capacity of human blood plasma and human urine: Simultaneous evaluation of the ORAC index and ascorbic acid concentration employing pyrogallol red as probe

The health-promoting effects of phenolic compounds depend on their bioaccessibility from the food matrix and their consequent bioavailability. We carried out a randomized crossover pilot clinical trial to evaluate the matrix effect (raw flesh and juice) of ‘Ataulfo’ mango on the bioavailability of its phenolic compounds. Twelve healthy male subjects consumed a dose of mango flesh or juice. Blood was collected for six hours after consumption, and urine for 24 h. Plasma and urine phenolics were analyzed by electrochemical detection coupled to high performance liquid chromatography (HPLC-ECD). Five compounds were identified and quantified in plasma. Six phenolic compounds, plus a microbial metabolite (pyrogallol) were quantified in urine, suggesting colonic metabolism. The maximum plasma concentration (Cmax) occurred 2–4 h after consumption; excretion rates were maximum at 8–24 h. Mango flesh contributed to greater protocatechuic acid absorption (49%), mango juice contributed to higher chlorogenic acid absorption (62%). Our data suggests that the bioavailability and antioxidant capacity of mango phenolics is preserved, and may be increased when the flesh is processed into juice.

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“…The protein-free supernatants were used in the ORAC assay. Urine samples were analyzed without previous dilution [ 22 ].…”

Section: Methodsmentioning

confidence: 99%

Processing ‘Ataulfo’ Mango into Juice Preserves the Bioavailability and Antioxidant Capacity of Its Phenolic Compounds

et al. 2017

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“…It has been shown that pyrogallol red (PGR) and pyranine (PYR) dyes react efficiently with reactive species [ 16 , 17 , 18 , 19 ]. The spectroscopic evaluation of the bleaching of these target molecules induced by peroxyl radicals has permitted the development of assays aimed at evaluating the antioxidant capacity of pure antioxidants, plants extracts, beverages and human fluids [ 18 , 20 , 21 , 22 , 23 , 24 , 25 ]. However, the factors determining the level of protection estimated from the use of these two probes are different.…”

Section: Introductionmentioning

confidence: 99%

Use of Pyrogallol Red and Pyranine as Probes to Evaluate Antioxidant Capacities towards Hypochlorite

et al. 2013

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Hypochlorite is a strong oxidant able to induce deleterious effects in biological systems. The goal of this work was to investigate the use of PGR and PYR as probes in assays aimed at evaluating antioxidant activities towards hypochorite and apply it to plant extracts employed in Chilean folk medicine. The consumption of PGR and PYR was evaluated from the decrease in the visible absorbance and fluorescence intensity, respectively. Total phenolic content was determined by the Folin Ciocalteau assay. PGR and PYR react with hypochlorite with different kinetics, being considerably faster the consumption of PGR. Different stoichiometric values were also determined: 0.7 molecules of PGR and 0.33 molecules of PYR were bleached per each molecule of added hypochlorite. Both probes were protected by antioxidants, but the rate of PGR bleaching was too fast to perform a kinetic analysis. For PYR, the protection took place without changes in its initial consumption rate, suggesting a competition between the dye and the antioxidant for hypochlorite. Plant extracts protected PYR giving a PYR-HOCl index that follows the order: Fuchsia magellanica ≈ Marrubium vulgare ≈ Tagetes minuta > Chenopodium ambrosoides ≈ Satureja montana > Thymus praecox. Based on both the kinetic data and the protection afforded by pure antioxidants, we selected PYR as the best probe. The proposed methodology allows evaluating an antioxidant capacity index of plant extracts related to the reactivity of the samples towards hypochlorite.

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“…In particular, ascorbic acid was the only antioxidant, among the tested compounds, that generated a clear induction time [ 11 , 12 ]. The ORAC-PGR method has been used, as a complementary methodology of ORAC-FL, to estimate the antioxidant capacity of complex mixtures including beverages [ 13 , 14 , 15 ], wines [ 10 , 11 ], fermented foods [ 16 ] fruit extracts [ 12 , 17 ], and human fluids [ 18 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

Antioxidant Capacity of Pure Compounds and Complex Mixtures Evaluated by the ORAC-Pyrogallol Red Assay in the Presence of Triton X-100 Micelles

et al. 2010

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The protective effect of different antioxidants and complex mixtures on the consumption of pyrogallol red (PGR) induced by peroxyl radicals was studied in the absence and presence of Triton X-100 micelles. The presence of micelles decreased significantly the protection of PGR afforded by lipophilic antioxidants (β-carotene, octyl gallate), while no effect of micelles was observed for hydrophilic antioxidants such as Trolox, caffeic acid, gallic acid, and ascorbic acid. In the presence of complex mixtures a clear effect of Triton X-100 micelles was also observed in the protection afforded by wines, tea infusions, and seed extracts of Eugenia jambolana and Myrciaria cauliflora. On the other hand, no effect of micelles was observed for orange juice and pulp fruit extracts. The ORAC (Oxygen Radical Absorbance Capacity) index was evaluated in the absence (ORAC-PGR) and presence of Triton X-100 micelles (ORAC-PGRMIC). Triton X-100 micelles affect ORAC-PGR values of antioxidants in a lipophilicity-dependent way. From the obtained results, we conclude that ORAC-PGR and ORAC-PGRMIC assays could be considered as an alternative to estimate the antioxidant ability (ORAC-PGR) and to infer the association to Triton X-100 micelles (ORAC-PGR/ORAC-PGRMIC) of pure antioxidants and their complex mixtures.

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Antioxidant capacity of human blood plasma and human urine: Simultaneous evaluation of the ORAC index and ascorbic acid concentration employing pyrogallol red as probe

Cited by 21 publications

References 34 publications

Processing ‘Ataulfo’ Mango into Juice Preserves the Bioavailability and Antioxidant Capacity of Its Phenolic Compounds

Processing ‘Ataulfo’ Mango into Juice Preserves the Bioavailability and Antioxidant Capacity of Its Phenolic Compounds

Use of Pyrogallol Red and Pyranine as Probes to Evaluate Antioxidant Capacities towards Hypochlorite

Antioxidant Capacity of Pure Compounds and Complex Mixtures Evaluated by the ORAC-Pyrogallol Red Assay in the Presence of Triton X-100 Micelles

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