A mutagenic screening of various herbs, spices, and food additives

Abstract

Chloroform and methanol extracts of various herbs and spices as well as food additives were screened for mutagenicity using the Salmonella/microsome assay of Ames and the Salmonella typhimurium strains TA100 and TA98. The results of this general screening, however, did not provide sufficient information to fully assess the mutagenic potential of certain herbs and spices since the assay of their respective extracts was accompanied by a growth inhibition of the bacterial tester strain. These findings were attributed to the effects of toxic compounds that were presumably contained within the complex mixtures that comprise both herbs and spices. An apparent reduction in the effects of toxicity was observed when separation methods were used as a means to obtain fewer compounds in each of the samples assayed for mutagenicity.

Following a separation by column chromatography of the chloroform and methanol extracts of cumin, a dose related response of weak mutagenicity was demonstrated toward TA100 but not TA98 with one of the 17 fractions collected. Positive responses to mutagenicity in the absence of toxicity were obtained when chloroform and methanol extracts and food additives were fed to rats, and the metabolites present in ether extracts of 24‐hour urine samples were subsequently assayed for mutagenicity. Weak mutagenic activities toward TA100 but not TA98 were observed with each of the urine extracts of rats fed the following samples: β terpineol, camphene, two separate combinations of the methanol fractions of cumin, a chloroform fraction of cumin, the combined chloroform and methanol fraction of star anise and either the chloroform or methanol fractions of tarragon. With the exception of the chloroform fraction of cumin, the extracts and food additives administered to rats appeared to require an in vivo metabolic activation to detect their mutagenic forms. Mutagenicity was only detected when the ether extracts of urinary metabolites were assayed, even though tests preceding the rat feedings were performed in the presence of the rat liver microsome fraction S9.