Acute (mouse and rat) and short-term (rat) toxicity studies on Black PN

Abstract

Acute toxicity studies in rats and mice and a short-term feeding study in rats have been carried out on Black PN. The acute intraperitoneal LD 50 in mice was estimated to be 0·5–1·0 g/kg for both sexes and in rats 0·9 g/kg for females and 1·2 g/kg for males. Orally, single doses up to 2 g/kg in mice and 5 g/kg in rats were tolerated without ill effect. Feeding of Black PN to rats at dietary levels of 0·0 (control), 0·3, 1·0 and 3·0% for 90 days evoked no adverse effect on the appearance or condition of the animals. Growth retardation which was associated with diminished food intake was evident only in males at the 3% level. Food refusal was probably due to an effect of the test material on palatability of the diet. Haematological examination and liver and kidney function tests revealed no untoward findings. Organ weight changes of toxicological significance were confined to males on the 3% level where increases were observed in the relative weights of the testes and kidneys. The types and incidence of histological changes were comparable in control and test groups. A no-effect level was established of 1% Black PN in the diet of rats for 90 days, a level equivalent to 500 mg/kg/day.