Antitumor component(s) of yogurt: fractionation

Two methods of fractionation were employed to separate antitumor component(s) from yogurt. First, yogurt was separated by dialysis. Although feeding of the dialyzate fraction to mice inoculated with Ehrlich ascites tumor cells resulted in 32.9% inhibition of tumor cell counts and 23.5 to 26.3% reduction of deoxynucleic acid content of ascitic fluid, feeding of the yogurt retentate did not reduce tumor proliferation. Second, an aqueous fraction of yogurt was prepared by removal of the ether soluble matter. Administration of aqueous fraction at 2 mg/mouse intravenously resulted in 25.1 to 32.3% less cell growth whereas intraperitoneal inoculation resulted in only 15.0 to 15.9% reduced tumor proliferation. Antitumor activity may be due to a component(s) with a molecular weight less than or equal to 14,000, and it presumably is not bound chemically to any larger compound because it could be separated by dialysis.