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

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 endothelial cells (HUVECs) in a tumor necrosis α (TNF-α) mediated pro-inflammatory environment. METHODS AND RESULTS: HUVECs were incubated with different concentrations (from 0.01 to 10 μg mL-1 ) of the compounds for 24 h. Labelled monocytic THP-1 cells were added to HUVECs and their adhesion was induced by TNF-α (100 ng mL-1 ). ACN-RF reduced THP-1 adhesion to HUVECs with a maximum effect at 10 μg mL-1 (-33%). PA-RF counteracted THP-1 adhesion at 0.01, 0.1 and 1 μg mL-1 (-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-1 (-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.