Antagonism between catalase and ascorbic acid in control of normal and neoplastic cell multiplication.

The authors studied the effects of a treatment with ascorbic acid on in vitro multiplication of ascites tumour cells (ATP C+), of fibroblast-like cells and of hepatocytes from chick embryos, by measuring [3H]thymidine incorporation into DNA. The results obtained show that the ATP C+ cells are the most sensitive to the toxic effects of the experimental treatment, while the hepatocytes are the most resistant cell population. A treatment with catalase was able to greatly reduce the damage caused by ascorbic acid on the ATP C+ cells. It is hypothesized that ascorbic acid inhibits cell multiplication by the H2O2 formed by its oxidation and that the cells having the highest level of catalase are more resistant to its toxic effects.