RT Journal Article SR Electronic T1 Identification of a Cranberry Juice Product that Inhibits Enteric CYP3A-Mediated First-Pass Metabolism in Humans JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 514 OP 522 DO 10.1124/dmd.108.024968 VO 37 IS 3 A1 Ngoc Ngo A1 Zhixia Yan A1 Tyler N. Graf A1 Daniel R. Carrizosa A1 Angela D. M. Kashuba A1 E. Claire Dees A1 Nicholas H. Oberlies A1 Mary F. Paine YR 2009 UL http://dmd.aspetjournals.org/content/37/3/514.abstract AB An in vivo study in rats showed a cranberry juice product to inhibit the intestinal first-pass metabolism of the CYP3A substrate nifedipine. However, a clinical study involving the CYP3A probe substrate midazolam and a different cranberry juice product showed no interaction. Because the composition of bioactive components in natural products can vary substantially, a systematic in vitro-in vivo approach was taken to identify a cranberry juice capable of inhibiting enteric CYP3A in humans. First, the effects of five cranberry juices, coded A through E, were evaluated on midazolam 1′-hydroxylation activity in human intestinal microsomes. Juice E was the most potent, ablating activity at 0.5% juice (v/v) relative to control. Second, juice E was fractionated to generate hexane-, chloroform-, butanol-, and aqueous-soluble fractions. The hexane- and chloroform-soluble fractions at 50 μg/ml were the most potent, inhibiting by 77 and 63%, respectively, suggesting that the CYP3A inhibitors reside largely in these more lipophilic fractions. Finally, juice E was evaluated on the oral pharmacokinetics of midazolam in 16 healthy volunteers. Relative to water, juice E significantly increased the geometric mean area under the curve (AUC)0-∞ of midazolam by ∼30% (p = 0.001), decreased the geometric mean 1′-hydroxymidazolam/midazolam AUC0-∞ ratio by ∼40% (p < 0.001), and had no effect on geometric mean terminal half-life, indicating inhibition of enteric, but not hepatic, CYP3A-mediated first-pass metabolism of midazolam. This approach both showed a potential drug interaction liability with cranberry juice and substantiated that rigorous in vitro characterization of dietary substances is required before initiation of clinical drug-diet interaction studies. The American Society for Pharmacology and Experimental Therapeutics