malvidin-3-glucoside and syringic-acid

Monocyte adhesion to the vascular endothelium is a crucial step in the early stages of atherogenesis. This study aims to investigate the capacity of an anthocyanin (ACN) and phenolic acid (PA) rich fraction (RF) of a wild blueberry, single ACNs (cyanidin, malvidin, delphinidin) and related metabolites (protocatechuic, syringic, and gallic acid) to counteract monocytes (THP-1) adhesion to human umbilical vein endothelial cells (HUVECs) in a tumor necrosis factor α (TNF-α) mediated proinflammatory environment.. HUVECs were incubated with different concentrations (from 0.01 to 10 μg/mL) of the compounds for 24 h. Labeled monocytic THP-1 cells were added to HUVECs and their adhesion was induced by TNF-α (100 ng/mL). ACN-RF reduced THP-1 adhesion to HUVECs with a maximum effect at 10 μg/mL (-33%). PA-RF counteracted THP-1 adhesion at 0.01, 0.1, and 1 μg/mL (-45, -48.7, and -27.6%, respectively), but not at maximum concentration. Supplementation with gallic acid reduced THP-1 adhesion to HUVECs with a maximum effect at 1 μg/mL (-29.9%), while malvidin-3-glucoside and syringic acid increased the adhesion. No effect was observed for the other compounds.. These results suggest that ACNs/PA-RF may prevent atherogenesis while the effects of the single ACNs and metabolites are controversial and merit further exploration.

Topics: Anthocyanins; Atherosclerosis; Blueberry Plants; Cell Adhesion; E-Selectin; Endothelium, Vascular; Gallic Acid; Glucosides; Human Umbilical Vein Endothelial Cells; Humans; Hydroxybenzoates; Intercellular Adhesion Molecule-1; Monocytes; NF-kappa B; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Anthocyanins are a natural source of pigments in plants and their processed food products have become attractive and excellent candidates to replace the synthetic colourants due to their characteristic intense colours and associated health benefits. The intermolecular copigmentation between anthocyanins and other colourless compounds has been reported to be an important way to enhance and stabilise the colour intensity of aqueous solutions. In the present work we report the equilibrium constant, stoichiometric ratio and the thermodynamic parameters (ΔG°, ΔH° and ΔS°) related to the intermolecular copigmentation reactions of the anthocyanin malvidin 3-O-glucoside with one hydroxycinnamic acid (p-coumaric acid) and two O-methylated hydroxybenzoic acids (vanillic and syringic acid). Different factors which affect their interactions such as copigment concentration, pH and temperature of the medium are examined at two pH levels (pH=2.50 and 3.65) corresponding to those of the major food mediums where these reactions take place (fruit juices, wine, jams etc.).

Topics: Anthocyanins; Coumaric Acids; Gallic Acid; Glucosides; Kinetics; Pigments, Biological; Spectrophotometry; Thermodynamics; Vanillic Acid