Supplementation with antioxidants prior to bone marrow transplantation

Conditioning therapy preceding bone marrow transplantation (BMT) usually consists of high-dose chemotherapy and total body irradiation (TBI). It has acute and delayed toxic effects on several tissues, possibly related to peroxidation processes and exhaustion of antioxidants. Early studies indicated an increase of peroxide processes and a decrease of antioxidants during conditioning therapy. Hence, we investigated the effect of antioxidant supplementation on peroxidation processes and antioxidant status. We supplemented a patient group (N = 16) [BMT (+)], with oral 45 mg beta-carotene, 825 mg alpha-tocopherol and 450 mg ascorbic acid daily for three weeks before conditioning therapy. Another patient group (N = 10), BMT(-), was not supplemented with antioxidants before conditioning therapy. In order to investigate the physiologic effect of supplement antioxidants a healthy control group (N = 10) was supplemented with the same doses as BMT(+). Peroxide concentrations in plasma were measured by using the cholesterol oxidase (CHOD)-iodide method and antioxidants were measured by HPLC. Before supplementation the beta-carotene and alpha-tocopherol concentrations were comparable in both patient groups. After supplementation significantly higher beta-carotene and alpha-tocopherol concentrations were measured in the supplemented patients, BMT(+), than in the unsupplemented patients, BMT(-). After conditioning therapy, BMT(+) patients showed a significantly higher beta-carotene concentration (p < 0.05) than before supplementation. In BMT(-) patients the beta-carotene (p < 0.05) and alpha-tocopherol concentrations (p < 0.01) decreased significantly and the lipid peroxide concentration increased significantly following conditioning therapy. We conclude that antioxidant supplementation prior to conditioning therapy reduces peroxidation processes induced by conditioning therapy in bone marrow recipients.