title: Modulatory effects of Kaempferia parviflora extract on mouse hepatic cytochrome P450 enzymes.
abstract: BACKGROUND
  Kaempferia parviflora is a herbal plant, the extracts of which are commonly used as alternative medicines. It widely uses as aphrodisiac, anti-inflammation, anti-microbacterial, and anti-peptic ulcer.
  
  
  OBJECTIVE
  In order to obtain an effective utilization and safety of the herb, the influence of Kaempferia parviflora on hepatic CYP450 metabolizing enzymes including CYP1A1, CYP1A2, CYP2B, CYP2E1, and CYP3A was investigated.
  
  
  METHODS
  The impact of Kaempferia parviflora on CYP450 both in vitro and in vivo was examined by using ethoxyresorufin O-dealkylation, methoxyresorufin O-dealkylation, pentoxyresorufin O-dealkylation, p-nitrophenol hydroxylation, and erythromycin N-demethylation assays, respectively.
  
  
  RESULTS
  In vitro studies using non-induced mouse hepatic microsomes in the presence or absence of Kaempferia parviflora extract showed that Kaempferia parviflora extract altered CYP1A1, CYP1A2, CYP2B, and CYP2E1 activities by non-competitive, mixed-competitive, competitive, and uncompetitive mechanisms, respectively. Among these enzymes, CYP1A2 was affected by Kaempferia parviflora based on the highest value of V(max) (15.276±0.206 nmol/min) and lowest of K(i) value (0.008±0.002 μg/ml). In addition, the plant extract also modulated CYP2B activity based on the low K(m) value (1.599±0.147 pmol). For in vivo studies, mice were orally treated with 250 mg/kg of Kaempferia parviflora extract for 7, 14, and 21 days. The results demonstrated that Kaempferia parviflora extract significantly induced CYP1A1, CYP1A2 enzyme activities following short-term treatment. CYP2B enzyme activities were markedly increased all Kaempferia parviflora extract treatment timepoints, whereas Kaempferia parviflora extract significantly enhanced CYP2E1 activity only after long-term treatment. However, Kaempferia parviflora extract did not affect the CYP3A enzyme activity.
  
  
  CONCLUSIONS
  Kaempferia parviflora extract modulated several CYP450 enzyme activities, thus, its utilization with drugs or other herbs should raise concern for potential drug-herb interactions.
authors.affiliation: Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand. catheleeya1@hotmail.com
authors.forename: Catheleeya
authors.initials: C
authors.lastname: Mekjaruskul
authors.forename: Michael
authors.initials: M
authors.lastname: Jay
authors.forename: Bungorn
authors.initials: B
authors.lastname: Sripanidkulchai
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D010936:Plant Extracts / Q000494:pharmacology*; D030521:Zingiberaceae
chemical_list: D007527:Isoenzymes; D010936:Plant Extracts; D003577:Cytochrome P-450 Enzyme System