Sarcoma Induced in Rats by Extracts of Plants and by Fractionated Extracts of Krameria ixina2

Abstract

Plant substances are suspected as among the causes of cancer in the esophagus. Extracts of 8 plants commonly used internally by natives of the island of Curacao, West Indies, where esophageal cancer is frequent, were assayed in NIH Black rats for the production of sarcoma by subcutaneous injection. Our aim was to develop a preliminary screening test for suspected plants. Extract of Acacia villosa root was highly toxic, and the size of the dose was reduced; sarcomas developed after short latent periods in 100% of the rats that survived the toxic effects. Root of Melochia tomentosa also produced sarcomas in 100% of treated rats; Heliotropium angiospermum (without root) produced sarcomas in 75% of the rats. Sarcomas did not develop in rats treated with plant materials from Annona glabra, Cajanus indic us, Capraria biflora, Mangifera indica, and Mentzelia aspera. A preliminary study was made of 3 fractions of whole Krameria ixina (without root), which produced sarcomas in 100% of rats in a previous experiment. Sarcomas did not develop after injections of a fraction in the aqueous extract after removal of tannins by precipitation with caffeine.