Description
Vitamins C, K3 (VC, VK3) and a VC/VK3 combination with a VC:VK3 ratio of 100:1 were assayed for their antitumour activity against two human prostatic carcinoma cell lines. Co-administration of the vitamins enhanced the antitumour activity 5- to 20-fold even with a 1 h exposure time. While exogenous catalase destroyed the antitumour activity, hydrogen peroxide-induced lipid peroxidation was negligible. Analysis of cellular ATP and thiol levels as well as DNA and protein synthesis revealed: a transient increase in ATP production, a decrease in DNA synthesis, an increase in protein synthesis and a decrease in thiol levels. These results suggested that the increased cytotoxicity of the vitamin combination was due to redox cycling and increased oxidative stress.
Subject
Adenosine Triphosphate/biosynthesis; Antineoplastic Agents/*pharmacology/toxicity; Antineoplastic Combined Chemotherapy Protocols/pharmacology; Ascorbic Acid/*pharmacology/toxicity; Carcinoma/*metabolism; Catalase/pharmacology; Cultured; DNA; Humans; Hydrogen Peroxide/metabolism; Lipid Peroxidation; Male; Neoplasm Proteins/biosynthesis; Neoplasm/biosynthesis; Prostatic Neoplasms/*metabolism; Sulfhydryl Compounds/analysis; Tumor Cells; Vitamin K/*pharmacology/toxicity