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

Abstract

Scope: 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.

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 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.

Conclusion: 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.

Keywords: Adhesion; Anthocyanins; Atherogenesis; Cell culture; Metabolites; Wild blueberry.