Induction of breast and lung neoplastic lesions in mice by alpha-ecdysone

Alpha ecdysone is naturally present in the leaves of some plants, including the carcinogenic plant bracken fern (Pteris aquilina). Feeding mice with alpha-ecdysone at a dose level of 3 ppm/25 g body weight, 2 times per week for 22 months induced a significant increase in the body weight of the animals. Breast and lung tumors developed in the experimental mice. Other pathological changes such as fibrocystic disease of the breast and bronchocentric granulomas appeared in these animals. The results of this study proved that alpha-ecdysone may be one of the active carcinogens in bracken fern plant which was responsible for induction of tumors in different animals investigated by previous authors.

Induction of breast neoplasia and lung granulomas in mice by an antifungal drug (griseofulvin)

Infiltrating duct carcinomas were induced in the mammary glands of 7 out of 60 experimental female mice force-fed with the antifungal drug griseofulvin, at a daily dose lever of 0.3 mg/30g body weight, for 12 months. The first mammary gland tumor appeared 8 months after the initiation of feeding. Other pathological changes such as bronchocentric granulomas appeared in some male and female treated animals (16.5%).

Prevention of skin tumors induced by 7,12-dimethylbenz(a)anthracene in mice by black seed oil

The effect of topical application of black seed oil on 7,12-dimethylbenz(a)anthracene (DMBA)-induced skin tumors in BALB/c mice was investigated. Topical application of chemically extracted oil (C.O.) and naturally extracted oil (N.O.) highly prevented the appearance of skin tumors in experimental animals. Skin tumors (papillomas and carcinomas) were initiated by application of 300 mu g DMBA (on days 1,8) followed by applying 0.5 mg croton oil, biweekly until the end of the experiment (25 weeks). The application of N.O. completely prevented the appearance of skin tumors in mice of group 3 versus a tumor incidence of 78.9% in animals of group 1 (carcinogenic control) (cc). Painting the skin of mice with C.O. (group 2) significantly reduced the tumor incidence to 14.2%. Moreover, a significant decrease was observed in number of mice bearing tumors, and number of tumors per mouse in group 2. Multiplicity was also decreased but insignificantly in the same group. The treatment with C.O. and N.O. insignificantly increased the rate of mice survival as compared to that of animals of group 1.

The use of toads (Bufo regularis) in a new biological assay for screening chemicals or drugs which induce leukaemia in man

Injection of Egyptian toads Bufo regularis, with adriamycin subcutaneously in the dorsal lymph sac at a dose level of 0.1 mg/toad, once every 3 weeks for 3 months induced pronounced alterations in the blood cells. These alterations were more or less similar to the criteria reported in human leukaemia. These changes were all comparable to those observed after the treatment of the experimental animals with the chemical carcinogen 7,12-dimethylbenz(a)anthracene. It is speculated that toads (Bufo regularis) can be used as biological test animals for screening chemicals or drugs which induce leukaemia in man.

Pathological-changes of the blood-cells in griseofulvin treated toads

Griseofulvin is a valuable oral antifungal drug, used extensively in the treatment of superficial fungal infections of man and animals. Electron microscopical studies of peripheral blood of toads force-fed with griseofulvin revealed pronounced alterations of the blood cells more or less similar to the criteria of monocytic leukaemia and were all comparable to those observed after the administration of the carcinogenic chemical 7,12 dimethylbenz(a)anthracene.