Acute toxicity study of the oil from Azadirachta indica seed (neem oil).

The seed oil of Azadirachta indica (neem oil) is well known for its medicinal properties in the indigenous Indian system of medicine. Its acute toxicity was documented in rats and rabbits by the oral route. Dose-related pharmacotoxic symptoms were noted along with a number of biochemical and histopathological indices of toxicity. The 24-h LD50 was established as 14 ml/kg in rats and 24 ml/kg in rabbits. Prior to death, animals of both species exhibited comparable pharmacotoxic symptoms in order and severity, with lungs and central nervous system as the target organs of toxicity. Edible mustard seed oil (80 ml/kg) was tested in the same manner to document the degree to which the physical characteristics of an oil could contribute to the oral toxicity of neem oil.