Genotoxicity of melanoidin fractions derived from a standard glucose/glycine model.

Genotoxic compounds can act at various levels in the cell (causing gene, chromosome, or genome mutations), necessitating the use of a range of genotoxicity assays designed to detect these different types of mutations. The production of melanoidins during the processing and cooking of foods is associated with changes in their nutritional character, and the discovery of mutagenic substances in pyrolyzed protein and amino acids has raised concern about the safety of these foods. The aim of this work was to test melanoidin fractions in three different in vitro assays (Ames test, Vitotox test, and micronucleus test). These melanoidin fractions were produced from the condensation of glucose with glycine and their separation was conducted by dialysis. The crude reaction mixture (before dialysis) and both the LMW and HMW fractions obtained by dialysis showed no genotoxicity in these assays, despite being tested at concentrations much higher than those naturally found in food products. The LMW fraction, however, showed toxicity at these high concentrations. The volatile fraction produced in this reaction showed genotoxicity only in the Vitotox test, at high concentrations.

Investigating the safety of plants used in South African traditional medicine: testing for genotoxicity in the micronucleus and alkaline comet assays.

Previous studies indicate that traditional botanical remedies can be valuable for treating human disease. The potential risk from long-term use of such remedies has not, however, been fully investigated, especially in terms of their potential carcinogenic activity. In the present study, 51 South African plant species were selected on the basis of their use in traditional medicine and crude extracts were sequentially prepared from different dried plant parts using dichloromethane followed by 90% methanol. These extracts were tested for genotoxic activity in human peripheral blood lymphocytes using the micronucleus test, with further testing of select extracts using the alkaline comet assay. Screening results indicated the induction of significant numbers of micronuclei by many of the plant extracts. Several samples also induced DNA damage in human white blood cells using the alkaline comet assay. Although a number of these plants are recognised as toxic by traditional healers, several plants that are used in common remedies were found to be genotoxic and potentially dangerous. Environ.