title: The effect of Cree traditional medicinal teas on the activity of human cytochrome P450-mediated metabolism.
abstract: BACKGROUND
  Rhododendron groenlandicum (Bog Labrador tea), Rhododendron tomentosum (Marsh Labrador tea) and Juniperus communis (Juniper) are used in medicinal teas by Canadian aboriginal cultures alone and in combination with conventional drug products. The safety of this combination had not been previously examined and this study was initiated to examine the potential of medicinal teas to inhibit the major human drug metabolizing enzyme, cytochrome P450 3A4 (CYP3A4).
  
  
  METHODS
  The decoctions of Rhododendron groenlandicum and Rhododendron tomentosum leaves and Juniperus communis berries were examined in a microtiter fluorometric assay to examine their potential to inhibit CYP-mediated metabolism.
  
  
  RESULTS
  The decoctions showed progressive inhibition towards CYP3A4 the longer the leaves or berries were brewed. R. Rhododendron groenlandicum and Juniperus communis may have the potential to inhibit CYP3A4-mediated metabolism.
  
  
  CONCLUSIONS
  The findings of this study with these traditional medicines are significant in that they provide mechanistic support that these products have the potential to affect the safety and efficacy of other health and medicinal products. As this study only examined CYP3A4, it is possible that these medicinals contain substances that could also affect other metabolic enzymes.
authors: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5; Centre for Research in Biopharmaceuticals and Biotechnology, University of Ottawa, Ottawa, ON, Canada K1H 8M5.
authors: Teresa W
authors: TW
authors: Tam
authors: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5; Centre for Research in Biopharmaceuticals and Biotechnology, University of Ottawa, Ottawa, ON, Canada K1H 8M5.
authors: Rui
authors: R
authors: Liu
authors: Centre for Research in Biopharmaceuticals and Biotechnology, University of Ottawa, Ottawa, ON, Canada K1H 8M5.
authors: Ammar
authors: A
authors: Saleem
authors: Centre for Research in Biopharmaceuticals and Biotechnology, University of Ottawa, Ottawa, ON, Canada K1H 8M5.
authors: John T
authors: JT
authors: Arnason
authors: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5; Centre for Research in Biopharmaceuticals and Biotechnology, University of Ottawa, Ottawa, ON, Canada K1H 8M5.
authors: Anthony
authors: A
authors: Krantis
authors: Department of Pharmacology, Université de Montréal, Montréal, QC, Canada H3C 3J7.
authors: Pierre S
authors: PS
authors: Haddad
authors: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada K1H 8M5; Centre for Research in Biopharmaceuticals and Biotechnology, University of Ottawa, Ottawa, ON, Canada K1H 8M5. Electronic address: bfoste2@uottawa.ca.
authors: Brian C
authors: BC
authors: Foster
mesh_terms: D001628:Beverages; D002170:Canada; D051544:Cytochrome P-450 CYP3A / Q000187:drug effects* / Q000378:metabolism; D065692:Cytochrome P-450 CYP3A Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D005470:Fluorometry; D005638:Fruit; D006801:Humans; D007198:Indians, North American; D018653:Juniperus / Q000737:chemistry*; D008519:Medicine, Traditional; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D029793:Rhododendron / Q000737:chemistry*; D013997:Time Factors
chemical_list: D065692:Cytochrome P-450 CYP3A Inhibitors; D010936:Plant Extracts; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human
keywords: Cree; Cytochrome P450; Juniperus communis; Labrador tea; Rhododendron groenlandicum; Traditional medicine