The effects of Artemisia filifolia and Helenium flexuosum on disposition of antipyrine in rabbits.

The objectives of the present experiment were to determine the effects of Artemisia filifolia or Helenium flexuosum ingestion on antipyrine disposition as an indirect index of mixed function oxidase (MFO) activity and to evaluate the rabbit as an animal model for assessing the impact of xenobiotics in food. Twelve adult male New Zealand white rabbits were acclimated and maintained on commercial rabbit pellets for 1 w before treatment commenced. On day 1, all rabbits were given 25 mg antipyrine/kg iv. Beginning on day 14, 6 of the rabbits were fed A filifolia and the other 6 were fed H flexuosum at 250 mg/kg daily for 5 d. Antipyrine injection was repeated in all rabbits on day 19. Serial blood samples were taken following each antipyrine administration and serum concentrations determined and subjected to pharmacokinetic analysis. Administration of H flexuosum significantly increased antipyrine half-life elimination from 99.5 +/- 15 min to 215.5 +/- 28 min, typical of an inhibitory-type effect on MFO. Administration of A filifolia was not accompanied by a significant change in antipyrine disposition. Rabbits appear to be appropriate animal models for evaluating the effect of plant ingestion on hepatic biotransformation.