Oxidation of human red blood cells by a free radical initiator and effects of radical scavengers.

Haemolysis induced by a free radical initiator (4,4'azobis-(4-cyanovaleric acid) has been studied with transfusion blood. Azobis cyanovaleric acid caused an increase in haemolysis. The effect of alpha- and gamma-tocopherol, 2,2,5,7,8 pentamethyl-6-chromanol and 2,2,7,8 tetramethyl-6-chromanol on the red blood cell haemolysis was studied. There was little difference in the antioxidant action of four chromanols studied. Compounds without the side chain appeared to suppress haemolysis as well as alpha- and gamma-tocopherol. These results suggest that the long side chain of vitamin E has little or no effect on its antioxidant activity in red blood cells. However "protection against haemolysis" was related to total chromanol content of red blood cells. Therefore by dividing "protection" by "total chromanol content" it can be seen that alpha-tocopherol has the highest antioxidant potency.