Carcinogenic activity of condensate from coloquint seeds (Citrullus colocynthis) after chronic epicutaneous administration to mice.

In the Sahelian countries coloquint seed tar is used in traditional medicine. A condensate from the seed of Citrullus colocynthis was obtained in a camel nomad settlement. It contained a large number of polycyclic aromatic hydrocarbons, including known carcinogens [e.g., benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene, benzo(j)fluoranthene]. The dose-related carcinogenic activity of this condensate was established after chronic epicutaneous application to mouse skin. We conclude that the manufacture and use of coloquint tar and related compounds may involve a health hazard and could lead to the development of cancer.