Evaluation of the toxic effects of aflatoxin B1 with a taste aversion paradigm in rats.

A taste aversion test was used to evaluate the toxic effects of aflatoxin (AF) B1 which is considered to be one of the most potent hepatocarcinogens known. Sixty male Fisher rats were randomly assigned to six treatment (injection) groups: Water (H2O); Dimethyl Sulphoxide (DMSO); Lithium Chloride (LiCl); 0.125 mg/kg AFB1 (AF-Low); 0.250 mg/kg AFB1 (AF-Medium) and 0.500 mg/kg AFB1 (AF-High). After adaption to a water-deprivation schedule which permitted 10-min access to water each day, the rats were given 10-min access to 0.1% saccharin solution which was followed by intraperitoneal injections of either H2O, DMSO, LiCl, or AF of varying doses according to group assignment. After a five-day recovery period, the rats were initially tested for a conditional taste aversion to the saccharin solution with a two-bottle test during the 10-min access period. Then, a series of two-bottle taste aversion tests were conducted in which H2O and saccharin solutions were available on an ad lib basis. The LiCl, AF-Low, AF-Medium, and AF-High groups developed strong aversions to the saccharin solution; whereas, the H2O and DMSO control groups did not. In addition, there was a dose-response relationship between the doses of aflatoxin and the level of aversion with the AF-High group demonstrating the most marked aversion throughout all saccharin tests. Retention tests showed that the taste aversion was still evident 30 days after the initial pairing of saccharin with AF.