Acute toxicity of pierisin-1, a cytotoxic protein from Pieris rapae, in mouse and rat.

To investigate the toxicity of pierisin-1, a cytotoxic protein present in the cabbage butterfly, Pieris rapae, pierisin-1 was administered via intraperitoneally in mice and rats and the effects examined. Common findings in these experiments were hypoactivity with a gradual decrease in body weight due to decreased food intake, relative polycythemia with low serum albumin concentration and atrophy of the thymus, spleen, seminal vesicles and adipose tissue. Characteristic findings were diarrhea, fusion and atrophy of the villi and dilatation of the crypts in the small intestine at 6-100 microg/kg in BALB/c mice as well as elevation of LDH activity and creatinine value, hemolysis and renal and hepatic injuries at 1,000 and 10,000 microg/kg in BALB/c mice. In the case of ICR mice, severer renal injury was observed. On the other hand, in Fischer 344/Du rats, sudden stop of food intake, elevation of both AST and ALT activities, interlobar adhesion of the right hepatic lobe, capsular thickening, septal fibrosis and single cell necroses of subcapsular hepatocytes in the liver and basophilic tubules in the kidneys were observed. Oral administration of pierisin-1 at a dose of 10,000 microg/kg in BALB/c mice did not exert any obvious effects. Thus, existence of species and strain differences in toxicity of pierisin-1 to animals was demonstrated.