title: Modulation of carcinogen-metabolizing cytochromes P450 by phytochemicals in humans.
abstract: BACKGROUND
  Cytochrome P450 (CYP) families 1 - 3, besides oxidizing environmental and dietary chemicals, leading to their elimination, catalyze the bioactivation of exogenous as well as endogenous carcinogens. Phytochemicals, particularly those which are active food components, were shown to be able to affect specific CYP expression and/or activity in animal models and in human in vitro systems. Human intervention studies involving healthy volunteers were also performed. This review describes human CYP modulation by naturally occurring phytochemicals which can not only affect carcinogen metabolism in humans, but also change the drug response.
  
  
  METHODS
  The authors present an overview of carcinogens metabolizing human CYP modulation in different model systems as well as studies on human dietary intervention. Furthermore, the authors provide examples of the phytochemicals that affect CYP expression and activity.
  
  
  CONCLUSIONS
  CYP, which are involved in carcinogen activation, can metabolize a range of substrates and inducing CYP by one substrate may also increase the metabolism of another. The ultimate proof of the efficacy of CYP modulation strategy for chemoprevention may be provided by clinical trials involving risk populations, which are difficult to perform. The new human-like models are highly desired for the study of modulation of carcinogen-metabolizing CYP.
authors: Poznan University of Medical Sciences, Department of Pharmaceutical Biochemistry, Poznań, Poland. baerw@ump.edu.pl
authors: Wanda
authors: W
authors: Baer-Dubowska
authors: Hanna
authors: H
authors: Szaefer
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000187:drug effects / Q000378:metabolism; D002273:Carcinogens / Q000378:metabolism*; D018890:Chemoprevention; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004032:Diet; D004195:Disease Models, Animal; D018565:Food-Drug Interactions / Q000502:physiology; D006801:Humans; D008658:Inactivation, Metabolic / Q000502:physiology; D064209:Phytochemicals / Q000494:pharmacology*
chemical_list: D002273:Carcinogens; D065607:Cytochrome P-450 Enzyme Inhibitors; D064209:Phytochemicals; D003577:Cytochrome P-450 Enzyme System