In vivo modification of adriamycin-induced apoptosis in L-5178Y lymphoma cell-bearing mice by (+)-α-tocopherol and superoxide dismutase

Apoptosis was followed in L5178Y lymphoma cell-bearing mice at different times after intraperitoneal injections of adriamycin (ADM). Apoptosis was determined morphologically and confirmed by DNA laddering on electrophoresis. Apoptosis was observed 36 h after injection of 5 mg/kg ADM (apoptotic cell index 64.2±5.6 vs. 1.5±2.1 from the untreated group) and confirmed by DNA electrophoresis. However, when the animals were pretreated with (+)-α-tocopherol acid succinate or superoxide dismutase before ADM administration apoptotic index significantly diminished (P<0.05) and the DNA electrophoresis did not show fragmentations. We conclude that in ADM-treated mice, tumour cell death occurs in two ways: first by necrosis, then later by apoptosis. These observations are likely to be associated with or caused by the generation of reactive oxygen species.