Inhibition of human platelet cyclooxygenase by alpha-tocopherol

Alpha-tocopherol, an inhibitor of platelet aggregation, was evaluated for its effects on the synthesis of thromboxane and prostaglandins. A dose-dependent reduction in thromboxane B2 and prostaglandin D2 synthesis was observed with approximately 60% inhibition at 5.0 IU or alpha-tocopherol. Alpha-tocopherol produced a time-dependent, irreversible inhibition.