Implication of the Polymeric Phenolic Fraction and Matrix Effect on the Antioxidant Activity, Bioaccessibility, and Bioavailability of Grape Stem Extracts.

The bioaccessibility and bioavailability of phenolics compounds of two grape stem extracts with different composition were studied. High polymeric extract (HPE) presented a higher content of total phenolics (TPC), procyanidins, hemicelluloses, proteins, and ashes, whereas low procyanidin extract (LPE) showed a higher fat, soluble sugars, and individual phenolic compounds content. Corresponding to its higher total phenolics content, HPE possesses a higher antioxidant activity (TEAC value). The digestion process reduced the antioxidant activity of the HPE up to 69%, due to the decrease of TPC (75%) with a significant loss of polymeric compounds. LPE antioxidant activity was stable, and TPC decreased by only 13% during the digestion process. Moreover, a higher antioxidant phenolic compounds bioavailability was shown in LPE in contrast to HPE. This behaviour was ascribed mainly to the negative interaction of polymeric fractions and the positive interaction of lipids with phenolic compounds. Therefore, this study highlights the convenience of carrying out previous studies to identify the better extraction conditions of individual bioavailable phenolic compounds with antioxidant activity, along with those constituents that could increase their bioaccessibility and bioavailability, such as lipids, although the role played by other components, such as hemicelluloses, cannot be ruled out.

Anti-Inflammatory and Antioxidant Activities from the Basolateral Fraction of Caco-2 Cells Exposed to a Rosmarinic Acid Enriched Extract.

The potential use of Origanum majorana L. as a source of bioavailable phenolic compounds, specifically rosmarinic acid (RA), has been evaluated. Phenolic bioavailability was tested using an in vitro digestion process followed by a Caco-2 cellular model of intestinal absorption. The high-performance liquid chromatography-photodiode array detector-tandem mass spectrometry (HPLC-PAD-MS/MS) analysis showed the main components in the extract were 6-hydroxyluteolin-7-O-glucoside and rosmarinic acid, followed by luteolin-O-glucoside. After digestion process, the amount of total phenolic compounds (TPC) only decreased slightly, although a remarkable reduction in RA (near 50%) was detected. Bioavailable fraction contained 7.37 ± 1.39 mg/L digested extract of RA with small quantities of lithospermic acid and diosmin and presented an important antioxidant activity (0.89 ± 0.09 mmol Trolox/L digested extract). Besides, this bioavailable fraction produced a significant inhibition in TNF-α, IL-1ß, and IL-6 secretion, using a human THP-1 macrophages model. Therefore, RA content in the basolateral compartment could play an important role in the antioxidant and anti-inflammatory activities found.

Peritonitis espontánea por Streptococcus equi subsp. zooepidemicus / Spontaneous peritonitis by Streptococcus equi subsp. zooepidemicus

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