Linus Pauling Institute

The growth of human lung carcinoma xenografts implanted beneath the renal capsule of immunocompetent mice was investigated (the six-day subrenal capsule assay) by using combinations of ascorbic acid and cupric ions. A maximum suppression of growth of this human lung tumor, LX-1, was observed at an estimated consumption level by the mice of 6 to 8 g ascorbic acid and 2 to 5 mg cupric ions per day per kg body weight. The data suggest that more than one oxidative or degradative product of ascorbic acid or of some copper compounds may be responsible for the observed antitumor activities, and that the chemotherapeutic effect is being produced at some stoichiometric ratios of ascorbic acid to cupric ions. When such a combination of the two substances was consumed by the mice, optimal therapeutic effect was exerted on the implanted xenografts.