Trial reportEuropean journal of clinical pharmacology2006
The extent of induction of CYP3A by St. John's wort varies among products and is linked to hyperforin dose.
Trial report in European journal of clinical pharmacology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 29 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
29 citing papers in PubMed, 1 synthesis or guideline pooled it, 117 citations in OpenAlex.
- Interactions between herbal medicines and prescribed drugs: an updated systematic review.Drugs · 2009Pooled it
- The effect of St John's wort on the pharmacokinetics of docetaxel.Clinical pharmacokinetics · 2014Trial
- St John's wort extract (Ze 117) does not alter the pharmacokinetics of a low-dose oral contraceptive.European journal of clinical pharmacology · 2009Trial
- No clinically relevant CYP3A induction after St. John's wort with low hyperforin content in healthy volunteers.European journal of clinical pharmacology · 2009Trial
- Hyperforin as a Multifunctional Specialized Metabolite of Natural Origin for Chronic Diseases: From Molecular Mechanisms to Clinical Translation.Current issues in molecular biology · 2026Review
- Dietary Modulation of CYP3A4 and Its Impact on Statins and Antidiabetic Drugs: A Narrative Review.Pharmaceuticals (Basel, Switzerland) · 2025Review
- St John's Wort (Complementary medicine research · 2025Observational
- Dose-dependent induction of CYP3A activity by St. John's wort alone and in combination with rifampin.Clinical and translational science · 2024Article
- Possible Side Effects of Polyphenols and Their Interactions with Medicines.Molecules (Basel, Switzerland) · 2023Review
- Alternatives to rifampicin: A review and perspectives on the choice of strong CYP3A inducers for clinical drug-drug interaction studies.Clinical and translational science · 2022Review
- Herb-Drug Interactions: Worlds Intersect with the Patient at the Center.Medicines (Basel, Switzerland) · 2021Review
- Pharmacokinetic Estimation Models-based Approach to Predict Clinical Implications for CYP Induction by Calcitriol in Human Cryopreserved Hepatocytes and HepaRG Cells.Pharmaceutics · 2021Article
- Pharmacokinetic Interactions between Herbal Medicines and Drugs: Their Mechanisms and Clinical Relevance.Life (Basel, Switzerland) · 2020Review
- Clinical relevance of St. John's wort drug interactions revisited.British journal of pharmacology · 2020Review
- Physiologically Based Pharmacokinetic Modelling of Hyperforin to Predict Drug Interactions with St John's Wort.Clinical pharmacokinetics · 2019Article
- The Development of a Database for Herbal and Dietary Supplement Induced Liver Toxicity.International journal of molecular sciences · 2018Article
- Role of CYP3A in Oral Contraceptives Clearance.Clinical and translational science · 2018Review
- Evaluation of a Novel Renewable Hepatic Cell Model for Prediction of Clinical CYP3A4 Induction Using a Correlation-Based Relative Induction Score Approach.Drug metabolism and disposition: the biological fate of chemicals · 2017Article
- Therapeutic Risk and Benefits of Concomitantly Using Herbal Medicines and Conventional Medicines: From the Perspectives of Evidence Based on Randomized Controlled Trials and Clinical Risk Management.Evidence-based complementary and alternative medicine : eCAM · 2017Review
- Review of the regulations for clinical research in herbal medicines in USA.Chinese journal of integrative medicine · 2014Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
11 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveInduction of CYP3A by St. John's wort (SJW) extracts with high hyperforin (HYF) content is well described. Since SJW products vary in the amount of HYF and other main constituents, the aim of the study was to evaluate the effect on CYP3A function of SJW preparations with a range from very low to high HYF content.
methodsForty-two male, healthy volunteers were randomized into six parallel SJW medication groups with varying composition especially with regard to HYF content. Midazolam plasma concentration profiles were characterized after a single oral dose of 7.5 mg midazolam on the day before and on the 14th day of SJW medication.
resultsAll SJW preparations tested resulted in a decrease in midazolam AUC, although the extent of the effect differed. The extract LI 160 (HYF 41 mg/day) decreased midazolam AUC0-12h by 79.4% (95% CI -88.6; -70.1), which was significantly greater than the effect by any other medication (p<0.05). SJW powder tablets 2.7 g/day (HYF 12 mg/day) resulted in a midazolam AUC0-12h decrease of 47.9% (95% CI -59.7;-36.2), while 2.7 g/day SJW powder tablets that were almost devoid of HYF (0.13 mg/day) reduced midazolam AUC0-12h by only 21.1% (95% CI -33.9; -8.3). Considering all six SJW medications tested, the extent of midazolam AUC decrease correlated significantly with increasing HYF dose (r=-0.765, p<0.001), but not with hypericin dose (r=-0.067; p=0.673).
conclusionThe extent of induction of CYP3A varies among St. John's wort products and depends on hyperforin dose.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.