©© 2008 American College of Clinical Pharmacology, Inc.
The Journal of Clinical Pharmacology
, 10.1177/0091270008314252
Possible Differential Induction of Phase 2 Enzyme and Antioxidant Pathways by American Ginseng, Panax quinquefolius
Lawrence S. Lee 1*,
Stephen D. Wise 2,
Clark Chan 2,
Teresa L. Parsons 1,
Charles Flexner 1,
and
Paul S. Lietman 1
1 Johns Hopkins University
2 Lilly-NUS Centre for Clinical Pharmacology, National University of Singapore
* To whom correspondence should be addressed. E-mail: llee3{at}jhsph.edu.
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Abstract |
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Human immunodeficiency virus (HIV)–infected patients often take herbal medicines, which may interact with antiretrovirals. American ginseng induces phase 2 and antioxidant enzymes in vitro and might increase the clearance of zidovudine and/or enhance antioxidant activity. Ten healthy volunteers received 300 mg of zidovudine orally before and after 2 weeks of treatment with a ginsenoside-enriched American ginseng extract 200 mg twice daily. This ginseng extract induced the phase 2 enzyme quinone reductase with an average concentration of doubling of enzyme activity of 190 µg/mL. Total ginsenoside content was 8.5 ± 0.5%. Pharmacokinetic profiles of zidovudine and oxidative stress marker concentrations were measured post-zidovudine dose. American ginseng does not significantly affect the formation clearance of zidovudine to its glucuronide (ratio post- to pre-American ginseng = 1.17; 90% confidence interval: 0.95-1.45; P = .21), total clearance (ratio = 0.97; 0.82-1.14; P = .70), or plasma zidovudine AUC0-8 (ratio = 1.03; 0.87-1.21; P = .77). Oxidative stress biomarkers are reduced post-American ginseng (F2-isoprostane ratio = 0.79; 0.72-0.86; P < .001; 8-hydroxydeoxyguanosine ratio = 0.74; 0.59-0.92; P = .02). Two weeks of American ginseng does not alter zidovudine pharmacokinetics but reduces oxidative stress markers.
