α‐Ecdysone, a new bracken fern factor responsible for neoplasm induction in the Egyptian toad (Bufo regularis)

Abstract

Neoplastic lesions were induced in 10 out of 58 experimental toads (Bufo regularis) force‐fed with α‐ecdysone, which naturally occurs in the leaves of bracken fern (Pteris aquilina). The results of this study prove that α‐ecdysone may be one of the factors responsible for the carcinogenicity of bracken fern plant fed to cattle and other experimental animals.