Vitamin E, having the well known antioxidant activity through scavenging free radicals و it occurs in several isomeric forms , these isomers have relatively different functions . One of these actions is related to its ability to inhibit platelets aggregation and hence thrombosis. The present study included a total number of apparently healthy 62 males . 11of them served as standard group , treated with 100 mg aspirin /day for more than one month . Another 31 subjects were randomly grouped into 5 groups that received different daily doses of α – tocopherol : 400 IU , 800 IU and 1200 IU for 2-6 months.The remainder ( 20 ) subjects served as a control group ( received no therapy ) . Platelets function was assessed based on measuring bleeding time and Slide Platelets Aggregation Time ( SPAT ) Meanwhile , thiobarbituric acid reactive substances (TBARS) were measured as a marker for oxidative stress. The results showed that the commercially available vitamin E preparations (α- tocopherol ) could exert anti-coagulant effect ,such effect is more dependant on duration of therapy , rather than dose related action .In addition to it’s antioxidant effect, which seems to be significantly correlated to it’s antiplatelets effect ( r=0.994 ,p<0.05).Hence , long term administration of high doses of vitamin E could be effective in decreasing the incidence of thrombosis ,which in turn depends on platelets function. Such effect might not affect bleeding time obviously , but it could reduce chances for platelets recruitment , which might represent an additional advantageous action for vitamin E over other antioxidants.
Key Words : Vitamin E , α - Tocopherol , Antiplatelets
