title: The effects of flavonoids on the ABC transporters: consequences for the pharmacokinetics of substrate drugs.
abstract: BACKGROUND
  The flavonoids are a large group of dietary plant compounds with suggested health benefits. There is accumulating evidence that many of these flavonoids can interact with the major drug transporters (and metabolizing enzymes) in the body, leading to alterations in the pharmacokinetics of substrate drugs, and thus their efficacy and toxicity.
  
  
  METHODS
  This review summarizes and updates the reported in vitro and in vivo interactions between common dietary flavonoids and the major drug-effluxing ABC transporters; these include P-glycoprotein, breast cancer resistance protein and multidrug resistance proteins 1 and 2. In contrast to previous reviews, the ADME of flavonoids are considered, along with their glycosides and Phase II conjugates. The authors also consider their possible interactions with the ABC transporters in the oral absorption, distribution into pharmacological sanctuaries and excretion of substrate drugs. Electronic databases, including PubMed, Scopus and Google Scholar were searched to identify appropriate in vitro and in vivo ABC transporter-flavonoid interactions, particularly within the last 10 years.
  
  
  CONCLUSIONS
  Caution is advised when taking flavonoid-containing supplements or herbal remedies concurrently with drugs. Further clinical studies are warranted to explore the impact of flavonoids and their metabolites on the pharmacokinetics, efficacy and toxicity of drugs.
authors.affiliation: Auckland University of Technology, Faculty of Health and Environmental Sciences, Department of Interdisciplinary Studies, Auckland, New Zealand.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: James W
authors.initials: JW
authors.lastname: Paxton
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D018528:ATP-Binding Cassette Transporters / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D002352:Carrier Proteins; D004032:Diet; D019587:Dietary Supplements; D004347:Drug Interactions; D004351:Drug Resistance / Q000187:drug effects; D005419:Flavonoids / Q000493:pharmacokinetics*; D006801:Humans; D006868:Hydrolysis; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism; D015262:Xenobiotics / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D000255:Adenosine Triphosphate; D002352:Carrier Proteins; D005419:Flavonoids; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015262:Xenobiotics; C421109:multidrug resistance-associated protein 1