Antiplatelts activity of vitamin E in relation to dose and duration of therapy

الملخص EN

Vitamin E, having the well known antioxidant activity through scavenging free radicals, 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.

11 of 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 dependent on duration of therapy , rather than dose related action .In addition to its antioxidant effect, which seems to be significantly correlated to its 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.