Original Paper Biochemistry and Molecular Biology	Planta Med 2005; 71: 640-645 DOI: 10.1055/s-2005-871270
© Georg Thieme Verlag KG Stuttgart · New York
Effects of Evodia rutaecarpa and Rutaecarpine on the Pharmacokinetics of Caffeine in Rats
Tung-Hu Tsai1, 2, Chun-Hao Chang3, Lie-Chwen Lin1
1 National Research Institute of Chinese Medicine, Taipei, Taiwan 2 Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan 3 Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan

Abstract

To assess possible herb-drug interactions, rutaecarpine (an herbal ingredient of Evodia rutaecarpa; 25 mg/kg/day, p. o.), the ethanol extract of Evodia rutaecarpa (1 g/kg/day, p. o.), and an herbal preparation of Evodia rutaecarpa (Wu-Chu-Yu-Tang; 1 g/kg/day) were individually pretreated daily for three consecutive days in rats and on the fourth day caffeine was administered (2 mg/kg, i. v.). Caffeine concentrations in blood, brain and bile were concurrently measured by microdialysis coupled to a liquid chromatographic system. Pharmacokinetic data were calculated by a non-compartmental model. The results indicate that the caffeine crosses the blood-brain barrier and goes through hepatobiliary excretion. The caffeine level was significantly decreased by the pretreatment of rutaecarpine, the extract of Evodia rutaecarpa and herbal preparation Wu-Chu-Yu-Tang. This finding should be very important whenever herb-drug interactions would be possible for a herbal remedy.

Key words

Caffeine - Evodia rutaecarpa - Rutaceae - microdialysis - pharmacokinetics - rutaecarpine - traditional Chinese medicine