Abstract
Alpha-tocopheryl acid succinate. when incubated at concentrations above 100 mg l - 1 with human red blood cells in a phosphate buffer pH 7.5, caused significant haemolysis of the cells. This effect appears to be unique to the succinate ester of alpha -tocopherol, since no haemolysis was observed under equivalent conditions with alpha -tocopherol itself, succinic acid or a range of other tocopherol compounds. Haemolysis was considerably reduced when the test solutions were deaerated before adding the tocopheryl succinate, which suggests the involvement of activated oxygen species in the lysis of the red blood cells. However, no activated oxygen species could be detected in the test solutions. When used as a dietary supplement, alpha -tocopheryl succinate should not cause haemolysis, since the ester is dissociated in the gut before absorption into the blood stream, and concentrations of alpha -tocopherol in the blood normally do not exceed 15 mg l- 1. Also, calcium and magnesium in blood serum were found to completely inhibit the haemolytic effect of tocopheryl succinate.