Phenolic profile of Douro wines and evaluation of their NO scavenging capacity in LPS-stimulated RAW 264.7 macrophages.

The phenolic profile of two samples of commercial Douro red wines, a table red wine (RM) and a Port wine (PR), was analysed by HPLC-DAD after purification by solid phase extraction (SPE). Eighteen phenolic compounds belonging to benzoic acids, hydroxycinnamic acids and anthocyanins were determined. The presence of tannins in both wines and of polymeric anthocyanins in Port wine could be inferred by the chromatograms registered at 280 and 500 nm, respectively. The wine extracts showed capacity to scavenge sodium nitroprusside-released nitric oxide (NO), RM being more effective than PR, which can be partly attributed to its higher content in monomeric anthocyanins. Using a model of macrophages (RAW 264.7 cells) stimulated with bacterial lipopolysaccharide (LPS) the samples showed a similar potential, which may indicate the importance of polymeric anthocyanins and the higher amount of phenolic acids present in PR to decrease cells NO levels.