1. Effects of individual ginsenosides, ginkgolides and flavonoids on CYP2C19 and CYP2D6 activity in human liver microsomes.
- Author
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He N, Xie HG, Collins X, Edeki T, and Yan Z
- Subjects
- Cytochrome P-450 CYP2C19, Cytochrome P-450 CYP2C9, Cytochrome P-450 CYP3A, Cytochrome P-450 Enzyme System metabolism, Dose-Response Relationship, Drug, Ethanolamines analysis, Ginkgo biloba chemistry, Humans, Inhibitory Concentration 50, Mephenytoin metabolism, Aryl Hydrocarbon Hydroxylases metabolism, Cytochrome P-450 CYP2D6 metabolism, Flavonoids pharmacology, Ginkgolides pharmacology, Ginsenosides pharmacology, Microsomes, Liver drug effects, Mixed Function Oxygenases metabolism
- Abstract
1. The effects of four individual ginsenosides (Rb1, Rb2, Rc and Rd), two ginkgolides (A and B) and one flavonoid (quercetin) on CYP2C19-dependent S-mephenytoin 4 cent-hydroxylation and CYP2D6-mediated bufuralol 1 cent-hydroxylation were evaluated in human liver microsomes. 2. Increasing concentrations of each test compound were added to microsomal incubation mixtures containing a well-characterized marker substrate (S-mephenytoin for CYP2C19 or bufuralol for CYP2D6) to determine their IC(50) values (compound concentration yielding 50% inhibition of a marker enzyme activity), which were estimated by graphical inspection. 3. For CYP2C19, the IC(50) values were 46, 46 and 62 micromol/L for ginsenoside Rd, quercetin and ginsenoside Rb2, respectively, whereas only ginsenoside Rd had an IC(50) value of 57 micromol/L for CYP2D6. 4. The data suggest that the tested compounds are not likely to inhibit the metabolism of the concurrent use of a given drug whose primary route of elimination is through CYP2C19 or CYP2D6.
- Published
- 2006
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