Dietary cancer risk from conditional cancerogens (tumor promoters) in produce of livestock fed on species of spurge (Euphorbiaceae) IV. Toxicologic and pathophysiologic observations in lactating goats and their suckling kidsfed on the irritant herbs Euphorbia nubica and Euphorbia helioscopia: an etiologic model for investigations on the putative risk of cancer by consumption of food polluted with tumor promoters

The feeding of lactating goats on usual green fodder, contaminated with Eup horbia helioscopia or E. nubica. results in poisoning of the dams as well a s their suckling kids. General signs of toxicity were emaciation, depressio n, shedding of body hair, arching Of back, and possible death. Post-mortem changes of dams and dead suckling kids included congestion and hemorrhage i n cardiac muscle, lung, liver, and kidneys. Blood analyses of goats exposed to these contaminants showed an increased level of serum alanine amino tra nsferase compared to control samples, indicating cellular destruction in th e liver. The latter was confirmed by histopathological changes in the organ which include severe congestion, necrosis, and degenerative changes. The g oats also suffered from deterioration of renal function as indicated by inc reased blood urea nitrogen and creatinine levels. In histopathologic inspec tions of kidney, severe congestion, hemorrhage in the cortex and medulla. a s well as necrosis of epithelial cells of kidney tubules were noticed. Cons iderable degenerative changes were also observed in heart and lung. The pat hophysiological appearances indicate that by feeding on the Euphoria specie s mentioned above, the goats are poisoned in a way similar to the case of E . peplus reported previously. Such intoxication most likely is due to irrit ant and hyperplasiogenic diterpene eater (DTE) toxins, usually present in t he aerial parts of Euphorbia species and well known as tumor promoters in m ouse skin. After ingestion of the toxic plant parts by the goats, the DTE t oxins might be metabolized and thereby partially detoxified. Yet, at least in part, the!: may show up in the milk of the goats, as indicated by severe poisoning of their suckling kids. As discussed previously in lactating goa ts fed on fodder contaminated with E. peplus, tumor promoters of the DTE ty pe may enter the human food chain via this source of milk. Such milk may be considered a valuable etiologic model for the investigation of economic, e cologic, and public health problems raised by human diet polluted with turn er promoters, i.e., conditional (non-genotoxic) cancerogens.