Antioxidative effects of α-tocopherol on stored human red blood cell units.

Background: Red blood cell (RBC) units undergo metabolic, structural, and biochemical changes known as "storage lesions" that can reduce the survival and quality of RBCs. The use of antioxidants such as α-tocopherol may help to improve the quality of RBC units by reducing oxidative stress. The aim of this study was to determine the antioxidant effect of α-tocopherol in RBC units containing citrate-phosphate-dextrose solution with adenine (CPDA1) stored at 1°C-6°C for 35 days.

Materials and methods: Four RBC units containing CPDA1 were divided into four equal satellite bags. Three bags were supplemented with 0.125, 0.625, and 3.125 mM concentrations of α-tocopherol as test groups. One bag was supplemented with ethanol (0.5%) as a control group. They were stored at 1°C-6°C for 35 days. Malondialdehyde (MDA) concentration, total antioxidant capacity (TAC), and hemolysis index (HI) were measured on days 0, 7, 14, 21, 28, and 35.

Results: In all groups, MDA concentration and HI increased and TAC decreased (P < 0.05). MDA concentration and HI in the 3.125 mM of the α-tocopherol group had a lower increase compared to the other test and control groups. Supplementation of RBC units with α-tocopherol resulted in a significant increase of TAC in all three groups compared to the control group (P < 0.05) and had a lower reduction during storage.

Conclusion: Supplementation of RBC units with α-tocopherol improves the quality of RBC units by decreasing lipid peroxidation and hemolysis and by increasing TAC. Among the mentioned concentrations, 3.125 mM of α-tocopherol had a significantly more antioxidant effect.