Heritable translocation test in mice with triethylenemelamine (TEM) and ergotamine

Alkaloids in food: a review of toxicity, analytical methods, occurrence and risk assessments

Alkaloids have been utilized by humans for years. They have diverse applications in pharmaceuticals. They have been proven to be effective in treating a number of diseases. They also form an important part of regular human diets, as they are present in food items, food supplements, diet ingredients and food contaminants. Despite their obvious importance, these alkaloids are toxic to humans. Their toxicity is dependent on a range of factors, such as specific dosage, exposure time and individual properties. Mild toxic effects include nausea, itching and vomiting while chronic effects include paralysis, teratogenicity and death. This review summarizes the published studies on the toxicity, analytical methods, occurrence and risk assessments of six major alkaloid groups that are present in food, namely, ergot, glycoalkaloids, purine, pyrrolizidine, quinolizidine and tropane alkaloids.

[Chemical and toxicologic studies of native corn in flour and bread]

During the bread-baking process, total alkaloid content is reduced by about 50%, the pharmacologically active alkaloids (the '-in' types) being reduced to a much greater extent than the less active type ('-inin' type). Using ergotamin and ergokryptin as a basis, total alkaloid levels were calculated from the HPLC data; these results were in a good agreement with the total alkaloid content calculated from 13 individual ergot alkaloids. The changes in the alkaloid spectrum caused by pelletin are shown. In feeding experiments with growing, pregnant, and lactating mice, diets with 0%, 1% and 2% unbaked (MM) or baked (MB) rye ergot were compared for possible toxic effects on reproduction, using animals fed ad libitum or pair-fed controls. A mean ingestion of 3.6 mg of alkaloids/kg body weight per day (MM 2%) was maternally toxic and caused inhibition of conception and implantation. Feeding with 1.3 or 1.6 mg of alkaloids/kg body weight per day (MM 1% and MB 2%) during pregnancy had no significant toxic effect on the embryo or fetus, but resulted in gestation time being prolonged to about 10 h. During lactation, an intake of 2.9 and 3.0 mg of alkaloids/kg body weight per day (MM 1% and MB 2%) led to a considerable reduction in growth (up to 50%) in the young mice compared to the control animals fed ad libitum. Both the determination of total ergot alkaloid content and the feeding experiment indicate that the bread-baking process causes a reduction and consequently a detoxification of ergot alkaloids of about 50%.

Triethylenemelamine: an initiator of two-stage carcinogenesis in mouse skin which lacks the potential of a complete carcinogen

The dorsal skin of female CD-1 mice was treated with triethylenemelamine (TEM) to determine whether this agent acted either as a complete carcinogen or as an initiator of carcinogenesis. A dose of 0.01-1.0 mumol of TEM applied once a week for 32 weeks to the skin of the backs of mice did not produce any detectable tumors. A dose of 2.5 mumol applied once a week over the same period produced only a single papilloma in a group of 20 mice. However, when mice were treated with a single dose of 1 mumol of TEM followed by promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA) twice a week, 88% of the mice produced papillomas after 28 weeks. Using the same protocol, a single application of hexamethylmelamine (HMM), pentamethylmelamine (PMM), or melamine followed by promotion with TPA had no significant tumor initiating activity. These data suggest that TEM acts primarily as an initiator of two-stage carcinogenesis.