Red wine polyphenols increase calcium in bovine aortic endothelial cells: a basis to elucidate signalling pathways leading to nitric oxide production

1 The present study investigates the mechanisms by which polyphenolic compounds from red wine elicit Ca2+ mobilization in bovine aortic endothelial cells (BAECs). Two polyphenol-containing red wine extracts, red wine polyphenolic compounds (RWPC) and Provinols(TM), and delphinidin, an anthocyanin were used. 2 RWPC stimulated a Ca2+-dependent release of nitric oxide (NO) from BAECs accounting for the relaxation of endothelium-denuded rat aortic rings as shown by cascade bioassay. 3 RWPC, Provinols(TM) and delphinidin increased cytosolic free calcium ([Ca2+](i)), by releasing Ca2+ from intracellular stores and by increasing Ca2+ entry. 4 The RWPC-induced increase in [Ca2+](i) was decreased by exposure to ryanodine (30 muM), whereas Provinols(TM) and delphinidin-induced increases in [Ca2+](i) were decreased by bradykinin (0.1 muM) and thapsigargin (1 muM) pre-treatment. 5 RWPC, Provinols(TM) and delphinidin-induced increases in [Ca2+](i) were sensitive to inhibitors of phospholipase C (neomycin, 3 mm; U73122, 3 muM) and tyrosine kinase (herbimycin A, 1 muM). 6 RWPC Provinols(TM) and delphinidin induced herbimycin A (1 muM)-sensitive tyrosine phosphorylation of several intracellular proteins. 7 Provinols(TM) released Ca2+ via both a cholera (CTX) and pertussis toxins (PTX)-sensitive pathway, whereas delphinidin released Ca2+ only via a PTX-sensitive mechanism, 8 Our data contribute in defining the mechanisms of endothelial NO production caused by wine polyphenols including the increase in [Ca2+](i) and the activation of tyrosine kinases. Furthermore, RWPC Provinols(TM) and delphinidin display differences in the process leading to [Ca2+](i) increases in endothelial cells illustrating multiple cellular targets of natural dietary polyphenolic compounds.