Nature 187, 335 - 336 (23 July 1960); doi:10.1038/187335b0

Tumour-promoting Effect of Excessively Large Doses of Oral Griseofulvin on Tumours induced in Mice by Methylcholanthrene

LOUIS L. BARICH, TAKASHI NAKAI, JAN SCHWARZ & DONNA JEAN BARICH

Department of Dermatology, College of Medicine, University of Cincinnati, Cincinnati, Ohio. Feb. 14.

LARGE intravenous doses of griseofulvin in rats have been found to arrest mitosis in metaphase in certain organs, for example, bone marrow, seminal epithelium and intestinal epithelium. We postulated that since griseofulvin taken orally is soon found in the keratin layer of the skin, there might be an antimitotic effect with a delay in the production, and a reduction in the number, of tumours that would be produced by applications of methylcholanthrene to the epidermis of mice. A pilot experiment was performed which gave quite unexpected results.