Effects of vitamin E on human platelet and mononuclear cell responses in vitro

Recent epidemiological studies have provided evidence supporting the potent ial benefits of antioxidants in coronary prevention. We have investigated t he effects of vitamin E on platelets, monocytes and endothelial cells in vi tro. Pre-incubation of platelets with vitamin E inhibited subsequent thromb in- (P<0.05, n=5), collagen- (P<0.0001, n=5) and ADP-(P<0.05, n = 4) induce d platelet aggregation measured using a microtitre plate method, or convent ional aggregometry. The adhesion of thrombin-activated platelets to collage n was also inhibited by vitamin E (P< 0.05, n = 8), but not by vitamin C (P >0.05, n=8); nor was the adhesion of unstimulated platelets significantly a ffected (P> 0.05, n= 8). Pre-incubation of monocytes with vitamin E inhibit ed their subsequent adhesion to plastic (P< 0.05, n = 9), and was also asso ciated with an 18% reduction in adhesion to EA.hy 926 endothelial cells (n= 8), although this failed to reach statistical significance. Pre-incubation of the endothelial cells with vitamin E also significantly reduced subsequ ent mononuclear cell adhesion by 56% (P< 0.05, n = 3).