Antiprotozoal activity in citrinin.

Citrinin has an inhibitory effect on growth of T. pyriformis. Citrinin also caused a shift to smaller cell size, particularly at the higher concentrations (25, 50 and 100 mug/ml). The mycotoxin exerted only a marginal effect on the respiration of T. pyriformis; but citrinin (25 mug/ml) induced an inhibitory effect on DNA, RNA and protein content. The greatest decrease was in RNA, while smaller decreases in protein and DNA were observed. A bioassay employing T. pyriformis was determined; the lower limit of citrinin detection was between 1 and 5 mug/ml.