Evaluating the Pharmacokinetics of Oregano and Potential Oregano-drug Interactions Using a Drug Cocktail Approach

Last updated: November 22, 2024
Sponsor: Washington State University
Overall Status: Active - Recruiting

Phase

1

Condition

N/A

Treatment

Drug cocktail

Oregano

Clinical Study ID

NCT06693960
20296
U54AT008909
  • Ages 18-64
  • All Genders
  • Accepts Healthy Volunteers

Study Summary

The purpose of this clinical trial is to determine how the supplement oregano affects how the body metabolizes pharmaceutical drugs.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Between 18-64 years old and healthy

  • Not taking any medications (prescription and non-prescription) or dietary/herbalsupplements that can interfere with study drug pharmacokinetics

  • Willing to abstain from consuming dietary/herbal supplements and citrus juices forseveral weeks

  • Willing to abstain from cannabis/marijuana, hemp, and THC- and CBD-containingproducts for several weeks

  • Willing to abstain from consuming caffeinated beverages or other caffeine-containingproducts the evening before and the morning of the first day of each study arm

  • Willing to abstain from consuming any alcoholic beverages for at least 1 day priorto any study day and during the study day

  • Willing to use a secondary method of birth control that does not include theintroduction or discontinuance of hormonal-based birth control (such as abstinence,copper IUD, or condoms). Specifically, regardless of the use hormonal-based birthcontrol, a non-hormonal method should be used for the duration of the study and forthree weeks following cessation of participation.

  • Willing to abstain from consuming oregano (as a food additive or otherwise) for theduration of the study

  • Geographically located within a 40-mile radius of Spokane and have the time toparticipate

Exclusion

Exclusion Criteria:

  • Under 18 or over 64 years old

  • Taking medications or dietary/herbal supplements that can interfere with study drugpharmacokinetics

  • Have a major illness

  • Taking medication/supplements for a mineral deficiency

  • History of intolerance or allergy to oregano or any of the cocktail drugs (caffeine,dextromethorphan, losartan, midazolam, and omeprazole)

  • Use of cannabis/marijuana, hemp, and CBD- and/or THC-containing products within thelast month

  • Currently using drugs or illicit substances for recreational purposes

  • Pregnant or nursing

  • Geographically located outside the 40-mile radius of Spokane and do not have thetime to participate

  • Cannot read and speak English

Study Design

Total Participants: 16
Treatment Group(s): 2
Primary Treatment: Drug cocktail
Phase: 1
Study Start date:
September 26, 2024
Estimated Completion Date:
December 31, 2025

Study Description

Oregano (Origanum vulgare) is a flowering plant native to Europe. The fresh or dried leaves are commonly used as a cooking herb. Oregano oil extracts are also marketed as herbal supplements. O. vulgare ranked as the number 12 top-selling herbal supplement in the natural channel in 2022. Oregano supplements are consumed for myriad purported medicinal properties, including antimicrobial, antioxidant, and anti-inflammatory effects. Oregano contains multiple types of compounds, including phenols, terpenes, and terpenoids. Recent compelling in vitro data showed that an extract of O. vulgare activated the human pregnane X receptor (PXR) and aryl hydrocarbon receptor (AhR), which regulate the expression and activity of the prominent drug metabolizing enzymes cytochrome P450 (CYP) 3A4 and CYP1A2, respectively. PXR also regulates the expression and activity of several other CYPs (e.g., CYP2C9, CYP2C19), as well as transporters (e.g., the efflux transporter P-glycoprotein (P-gp)). The extent of activation of both receptors by O. vulgare rivaled that of St. John's wort, a well-known herbal supplement that induces CYP and P-gp activity in human participants. These investigators next evaluated the effects of O. vulgare on CYP3A4 and CYP1A2 activity in human hepatocytes. Again, the extent of induction by O. vulgare rivaled that of St. John's wort. Collectively, these observations suggest that oregano supplements could precipitate numerous interactions with pharmaceutical drugs.

The primary objective of the proposed study is to evaluate the potential for a well-characterized O. vulgare product to precipitate pharmacokinetic interactions with a "cocktail" of oral drugs that are substrates for multiple CYPs. The investigators and others have shown this validated cocktail (caffeine, dextromethorphan, losartan, midazolam, and omeprazole) to be safe to administer to healthy adult participants. The secondary objective is to determine the pharmacokinetics of the oregano supplement, which to date have not been rigorously characterized in humans. Results will be used to help inform healthcare practitioners and consumers about the safe use of this increasingly popular herbal supplement when consumed with certain pharmaceutical drugs.

Connect with a study center

  • Washington State University College of Pharmacy and Pharmaceutical Sciences

    Spokane, Washington 99202
    United States

    Active - Recruiting

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