Potential Carcinogens. I. Carcinogenicity of Some Plant Extracts and Their Tannin-Containing Fractions in Rats2

Abstract

NIH Black rats were given ≤75 subcutaneous injections weekly of the total aqueous extracts of Krameria ixina (plant sans root), K. triandra (root), Acacia villosa (root), and Sorghum vulgare (seed); tannin-containing fractions of K. ixina, K. triandra, and A. villosa and a tannin-free fraction of K. ixina were also used. The total extracts and the tannin-containing fractions of K. ixina, K. triandra, and A. villosa produced malignant fibrous histiocytomas after varying numbers of injections. The tannin-free fractions had little carcinogenicity. Generally, the tannin-containing fractions contained most of the carcinogenic material. The materials from A. villosa produced tumors in the shortest time and were the most potent.