Different effects of anthocyanins and phenolic acids from wild blueberry (Vaccinium angustifolium) on monocytes adhesion to endothelial cells in a TNF-α stimulated proinflammatory environment

Scope: Monocyte adhesion to the vascular endothelium is a crucial step in the early stagesof atherogenesis. This study aims to investigate the capacity of an anthocyanin (ACN) andphenolic acid (PA) rich fraction (RF) of a wild blueberry, single ACNs (cyanidin, malvidin,delphinidin) and related metabolites (protocatechuic, syringic, and gallic acid) to counteractmonocytes (THP-1) adhesion to human umbilical vein endothelial cells (HUVECs) in a tumornecrosis factor ␣ (TNF-␣) mediated proinflammatory environment.
Methods and results: 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 HUVECsand their adhesion was induced by TNF-␣ (100 ng/mL). ACN-RF reduced THP-1 adhesionto HUVECs with a maximum effect at 10 µg/mL (−33%). PA-RF counteracted THP-1 adhe-sion at 0.01, 0.1, and 1 µg/mL (−45, −48.7, and −27.6%, respectively), but not at maximumconcentration. Supplementation with gallic acid reduced THP-1 adhesion to HUVECs with amaximum effect at 1 µg/mL (−29.9%), while malvidin-3-glucoside and syringic acid increasedthe adhesion. No effect was observed for the other compounds.
Conclusion: These results suggest that ACNs/PA-RF may prevent atherogenesis while theeffects of the single ACNs and metabolites are controversial and merit further exploration.