A comparative study on aflatoxin B 1 metabolism in mice and rats

In vivo metabolic studies on rats and mice revealed a marked difference in the fluorescent compounds produced after ingestion of aflatoxin B(1). The mouse converted aflatoxin B(1) to three unknown fluorescent compounds, designated x(1), x(2) and x(3) and the known aflatoxin M(1), while the rat was only capable of producing aflatoxin M(1). The results suggested that metabolites x(1), x(2), x(3) and aflatoxin M(1) were not part of a major metabolic pathway, but produced independently. These unknown yellowish-green fluorescent compounds did not seem to be conjugated with sulphate or glucuronic acid.In vitro incubations of various mouse liver cell fractions with aflatoxin B(1) showed that metabolites x(1), x(2), x(3) and aflatoxin M(1), could only be produced by the microsomal fraction and that NADPH was needed as a co-factor. The differences in aflatoxin metabolism by mice and rats are discussed in relation to the apparent resistance of the mouse to the carcinogenic effects of this toxin.

Rapid Method for the Isolation of Pure Aflatoxins

A chromatographic method is described for the preparation of pure aflatoxins from crude aflatoxin-containing extracts. The stationary phase consists of aluminum oxide (basic, according to Brockman) containing 6.25% oxalic acid dihydrate. The main advantage of this method is that pure samples of individual aflatoxins may be obtained in less than 2 hr. An additional advantage is economy of materials.

Estimation of Afiatoxin M in Milk

The ability of various solvents, using a Soxhlet extractor and a mechanical shaker, to extract anatoxin M from freeze-dried milk powder was compared. Extraction is most efficient when the sample is extracted with an azcotropic mixture of acetone-chlo-roform-water in a Soxhlet apparatus.