Inhibition of platelet aggregation by alpha-tocopherol and its nicotinate and acetate esters

Two esters of vitamin E, dl-a-tocopheryl nicotinate and dl-a-tocopheryl acetate were found to be more inhibitors than tocopherol itself on platelet aggregation induced by arachidonic acid and collagen. The nicotinate was 1--5 times more potent than the acetate and 2--18 times more potent than the unesterified tocopherol in inhibiting collagen induced aggregation in human citratet platelet-rich plasma.