Abstract
Pharmacological activities of the root bark of A. nobilis were tested in vivo and in vitro. The plant material was defatted with petroleum ether and then extracted with 70% ethanol. The LD 50 of the ethanol extract in mice at 24 h was 200 mg/kg, i.p. Poisoned mice showed neurologic signs prior to death. The extract showed no significant effect on pentobarbitone-induced hypnosis in mice after an i.p. injection. On oral administration of 67 mg/kg, the ethanol extract reduced pentobarbitone-induced sleep in CCl 4 -poisoned mice, an effect which was comparable to that of silibinin. Elevation of serum GOT and GPT induced by CCl 4 intoxication in rats were also significantly attenuated by the ethanol extract. The extract did not reduce the level of parasitaemia in mice infected with Trypanosoma brucei brucei. It induced a concentration-dependent relaxation in isolated guinea-pig ileum. The active principle responsible for the effect on the guinea-pig ileum appeared to be contained in the polar fraction of the extract.