High-dose supplementation with natural α-tocopherol does neither alter the pharmacodynamics of atorvastatin nor its phase I metabolism in guinea pigs
- Institute of Biological Chemistry and Nutrition, University of Hohenheim, D-70599 Stuttgart (Germany)
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, D-70376 Stuttgart (Germany)
It has been hypothesized in the literature that intake of high-dosage vitamin E supplements might alter the expression of cytochrome P{sub 450} enzymes (CYP), particularly CYP3A4, which may lead to adverse nutrient–drug interactions. Because previously published studies reported conflicting findings, we investigated the pharmacodynamics of the lipid-lowering drug atorvastatin (ATV), a CYP3A4 substrate, in response to high-dose α-tocopherol (αT) feeding and determined protein expression and activities of relevant CYP. Groups of ten female Dunkin–Hartley guinea pigs were fed a control (5% fat) or a high-fat control diet (HFC; 21% fat, 0.15% cholesterol) or the HFC diet fortified with αT (250 mg/kg diet), ATV (300 mg/kg diet) or both ATV + αT for 6 weeks. Relative to control, HFC animals had increased serum cholesterol concentrations, which were significantly reduced by ATV. High-dose αT feeding in combination with ATV (ATV + αT), albeit not αT feeding alone (αT), significantly lowered serum cholesterol relative to HFC, but did not alter the cholesterol-lowering activity of the drug compared to the ATV treated guinea pigs. Protein expression of CYP3A4, CYP4F2, CYP20A1 and OATP C was similar in all groups. Accordingly, no differences in plasma concentrations of phase I metabolites of ATV were observed between the ATV and ATV + αT groups. In conclusion, feeding guinea pigs high-doses of αT for 6 weeks did neither alter the hepatic expression of CYP, nor the pharmacodynamics and metabolism of ATV. High-dose αT intake is thus unlikely to change the efficacy of drugs metabolized by CYP enzymes, particularly by CYP3A4. -- Highlights: ► Vitamin E-atorvastatin interactions were studied in hypercholesterolemic guinea pigs. ► High-dose α-tocopherol did not alter the lipid-lowering efficacy of atorvastatin. ► α-Tocopherol did not change the expression of CYP3A4, CYP4F2, CYP20A or OATP C. ► α-Tocopherol did not affect phase I metabolism of atorvastatin. ► Vitamin E does not change atorvastatin pharmacodynamics or toxicity in guinea pigs.
- OSTI ID:
- 22216059
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 266, Issue 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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