Effect of vitamin E on toxicity and antitumor activity of adriamycin in mice

The use of vitamin E as a protective agent against adriamycin-induced toxicity in CDF1 and BDF1 mice resulted in potentiation of the chemotherapeutic index of adriamycin. A single dose of 15 mg of adriamycin per kg body weight produced a significantly reduced mean survival time. A dosage of adriamycin of 15 mg per kg body weight was employed in the following experiments. In P388 ascites tumor-bearing mice, four consecutive injections of several doses of vitamin E before injection of adriamycin produced a significant prolongation of the mean survival. In concomitant studies of serum tocopherol content, 7 to 10 micrograms/ml appeared to be an appropriate serum concentration, in accordance with the result of our previous report on its immunopotentiation effect. alpha-tocopherol seemed to have a two- to three-fold greater physiological activity than alpha-tocopheryl acetate. Dietary vitamin E treatments offered no protection against adriamycin toxicity, because the serum tocopherol content reached only 4.39 micrograms/ml in mice given the vitamin E-sufficient feed in this study. The results suggested that an increase of the serum tocopherol level to about two to three times the untreated control would be required before the adriamycin treatment to reduce its toxicity.