[{"id":2,"uid":"NPDI-yvZDKA","name":"Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers.","napdiIdentifier":"PMID:15319329","overallSummary":"Green tea extract is a widely used dietary supplement. The objective of this study was to assess the influence of a decaffeinated green tea (DGT; Camellia sinensis) extract on the activity of the drug-metabolizing enzymes cytochrome P-450 2D6 and 3A4. Probe drugs dextromethorphan (30 mg, CYP2D6 activity) and alprazolam (ALPZ; 2 mg, CYP3A4 activity) were administered orally to healthy volunteers (n = 11) at baseline, and again after treatment with four DGT capsules/day for 14 days. Each DGT capsule contained 211 +/- 25 mg of green tea catechins and <1 mg of caffeine. Dextromethorphan metabolic ratios (DMRs) and alprazolam pharmacokinetics were determined at baseline and after DGT treatment. There were no significant differences in ALPZ pharmacokinetics at baseline and after DGT treatment (all P values >/= 0.05; maximum concentration in plasma, 33 +/- 8 versus 34 +/- 13 ng/ml; time to reach maximum concentration in plasma, 1.4 +/- 1.2 versus 1.4 +/- 1.2 h; area under the plasma concentration versus time curve, 480 +/- 119 versus 510 +/- 107 h. ng. ml(-1); half-life of elimination, 12.3 +/- 1.7 versus 13.1 +/- 3.4 h). The DMR was 0.053 +/- 0.045 at baseline and 0.041 +/- 0.032 after DGT supplementation (P > 0.05). The plasma concentration of the green tea flavonoid, (-)-epigallocatechin gallate, reached 1.3 +/- 1.8 microM 2 h after DGT treatment. Our results indicate that DGT is unlikely to alter the disposition of medications primarily dependent on the CYP2D6 or CYP3A4 pathways of metabolism.","pubmedId":15319329,"embaseId":null,"croIdentifier":"N/A","croInformation":"Medical University of South Carolina General Clinical Research Center","dateStart":null,"dateEnd":null,"internalComment":"This study is reported in the literature. The data was entered by RB and reviewed by JS.","status":"published","compoundId":null,"naturalProductUid":"NP-028bf4b2-0bc6-458f-b86f-6930ce40efc6","naturalProductSampleId":null,"studySourceTypeId":1,"naturalProduct":{"uid":"NP-028bf4b2-0bc6-458f-b86f-6930ce40efc6","binomial":"Camellia sinensis","name":"Green tea","itis":null,"srs":"e9698137-24da-46f8-a70e-43e27691491f","source_id":"","conceptId":null},"compound":null,"studySourceType":{"id":1,"name":"Published report"},"experiments":[{"id":2,"uid":"NPDI-cY8J6A","name":"CYP2D6 inhibition experiment","overallEffect":0,"isControlData":false,"isIc50Shift":false,"croCutoff":null,"croIdentifier":null,"comment":null,"experimentalConditionsComment":null,"resultsComment":null,"internalComment":null,"objectCompoundId":12,"objectMetaboliteCompoundId":null,"precipitantCompoundId":39,"cytochromeB5Id":null,"studyId":2,"experimentTypeId":9,"testSystemId":null,"ic50ShiftExperimentId":null,"controlDataExperimentId":null,"controlDataForExperimentId":null,"naturalProductSampleId":null,"experimentType":{"id":9,"name":"In Vivo Interaction","isInVitro":false,"isTransporter":false,"isEnzyme":false,"purl":"http://purl.obolibrary.org/obo/DIDEO_00000071"},"objectCompound":{"id":12,"name":"dextromethorphan","unii":"7355X3ROTS","inChIKey":"MKXZASYAUGDDCJ-NJAFHUGGSA-N","publicDescription":null,"internalComment":null,"conceptId":1119510,"enantiomerOfId":null},"precipitantCompound":{"id":39,"name":"green tea leaf extract","unii":null,"inChIKey":null,"publicDescription":null,"internalComment":null,"conceptId":null,"enantiomerOfId":null},"objectMetaboliteCompound":null,"enzymes":[{"id":10,"name":"CYP2D6","conceptId":4173631,"experiment_enzyme_xref":{"enzymeId":10,"experimentId":2}}],"transporters":[],"quantifiedMetabolites":[]},{"id":3,"uid":"NPDI-_MbFQg","name":"In vivo NPDI experiment","overallEffect":0,"isControlData":false,"isIc50Shift":false,"croCutoff":null,"croIdentifier":null,"comment":null,"experimentalConditionsComment":null,"resultsComment":null,"internalComment":null,"objectCompoundId":38,"objectMetaboliteCompoundId":null,"precipitantCompoundId":39,"cytochromeB5Id":null,"studyId":2,"experimentTypeId":9,"testSystemId":null,"ic50ShiftExperimentId":null,"controlDataExperimentId":null,"controlDataForExperimentId":null,"naturalProductSampleId":null,"experimentType":{"id":9,"name":"In Vivo Interaction","isInVitro":false,"isTransporter":false,"isEnzyme":false,"purl":"http://purl.obolibrary.org/obo/DIDEO_00000071"},"objectCompound":{"id":38,"name":"alprazolam","unii":null,"inChIKey":"VREFGVBLTWBCJP-UHFFFAOYSA-N","publicDescription":null,"internalComment":null,"conceptId":781039,"enantiomerOfId":null},"precipitantCompound":{"id":39,"name":"green tea leaf extract","unii":null,"inChIKey":null,"publicDescription":null,"internalComment":null,"conceptId":null,"enantiomerOfId":null},"objectMetaboliteCompound":null,"enzymes":[{"id":13,"name":"CYP3A4","conceptId":4306811,"experiment_enzyme_xref":{"enzymeId":13,"experimentId":3}}],"transporters":[],"quantifiedMetabolites":[]}]}]