Effects of monosodium glutamate on food acceptance and toxicity of selenium in rats

Food acceptance and toxic effects of feeding sodium selenite (Se) alone and in combination with monosodium glutamate (MSG), a taste enhancer were studied in the laboratory rat. Dose-dependent stimulation of daily food intake was observed with MSG offered in no-choice or bi-choice with the plain food. Consumption of pellets containing 0.05, 0.5 and 1.0% Se was significantly low than the plain or MSG containing pellets but their active ingredient was sufficient to cause mortality of rats. Food pellets containing both MSG and Se in no-choice feeding trial were not preferred by the rats, as their consumption remained low as compared to pellets containing only MSG. However, prior feeding on MSG containing pellets for two days increased the amount of intake of Se-containing pellets. No mortality of rats feeding on pellets containing different concentrations of MSG was recorded. Feeding on Se-containing pellets caused dose-dependent mortality on the third day of the trial. As compared to rats feeding on Se-containing pellets, the mortality rate was reduced in those provided Se in combination with MSG but the intake of active ingredient of Se in both these trials did not differ significantly. Decrease in death rate of rats feeding on Se in combination with MSG containing pellets suggested that addition of MSG to seleniferous food probably provide protection to some extent from the toxic effects of selenium. However, combination of excess doses of MSG and Se in food pellets caused mortality of all experimental animals.