CYP2C19 Variants and Limonene Metabolism

NCT ID: NCT05078723

Last Updated: 2024-12-16

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

20 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-10-30

Study Completion Date

2026-12-31

Brief Summary

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The investigators will examine whether a non-invasive screening tool for CYP2C19 genetic variants can be developed by measuring limonene metabolism.

Detailed Description

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Cytochrome P450 2C19 is an important enzyme that metabolizes many drugs. However, individuals with genetic variants of CYP2C19, such as CYP2C19\*2 and CYP2C19\*3, are poor metabolizers of these drugs. Therefore, it is of interest to determine whether the investigators can develop a non-invasive assay to identify genetic variants of CYP2C19 by using a substrate for CYP2C19 found in citrus fruit, limonene. The purpose of the study is to examine changes in limonene levels in human breath after drinking orange peel extract for people with CYP2C19\*2 and CYP2C19\*3 genetic variants versus those that do not.

Conditions

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CYP2C19 Genetic Variants

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

SINGLE_GROUP

Human volunteers participating in this study will be given an over the counter orange peel extract and limonene levels will be measured.
Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

We are using quantitative assays for this study which reduce the need for masking of the participant or investigator.

Study Groups

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CYP2C19*2 and CYP2C19*3 Variants

The group of participants has been genotyped to have the CYP2C19\*2 and/or CYP2C19\*3 variant during the first part of the study. The participants will consume 1 oz water mixed with 500mg limonene (Jarrow Formula orange peel extract) and be asked to swish 5 times and swallow. All participants will then provide breath samples over the course of 2 hours. The breath sample outcomes will be compared to those of the wild-type CYP2C19 study subjects.

Group Type EXPERIMENTAL

Limonene

Intervention Type DIETARY_SUPPLEMENT

The investigators will ask the participants to swish 5 times and swallow 1 oz water mixed with 500mg limonene (Jarrow Formula orange peel extract). The participant will be monitored for a total of 2 hours. Breath samples will be acquired at a total of 11 time points throughout the study. Measurements include 2 baseline measurements followed by the orange peel extract consumption.

Wildtype CYP2C19

The group of participants has been genotyped to have wild-type CYP2C19. The participants will consume 1 oz water mixed with 500mg limonene (Jarrow Formula orange peel extract) and be asked to swish 5 times and swallow. All participants will then provide breath samples over the course of 2 hours. The breath sample outcomes will be compared to those of the CYP2C19\*2 and/or CYP2C19\*3 study subjects.

Group Type EXPERIMENTAL

Limonene

Intervention Type DIETARY_SUPPLEMENT

The investigators will ask the participants to swish 5 times and swallow 1 oz water mixed with 500mg limonene (Jarrow Formula orange peel extract). The participant will be monitored for a total of 2 hours. Breath samples will be acquired at a total of 11 time points throughout the study. Measurements include 2 baseline measurements followed by the orange peel extract consumption.

Interventions

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Limonene

The investigators will ask the participants to swish 5 times and swallow 1 oz water mixed with 500mg limonene (Jarrow Formula orange peel extract). The participant will be monitored for a total of 2 hours. Breath samples will be acquired at a total of 11 time points throughout the study. Measurements include 2 baseline measurements followed by the orange peel extract consumption.

Intervention Type DIETARY_SUPPLEMENT

Eligibility Criteria

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Inclusion Criteria

* Age range: Greater than 18 years and less than 45 years.
* Gender: Male or Female
* Ethnicities: East Asian

Exclusion Criteria

* Pregnant and/or Breastfeeding
* previous allergic reaction to limonene, citrus fruits, bovine gelatin, glycerin
* past medical history of cerebrovascular or cardiovascular disease
* veganism
* history of chest pain or shortness of breath in the past month
* certain medications that are CYP2C19 substrates or CYP2C19 inhibitors
* Non-East Asian descent
* age less than 18 y.o or age greater than 45 y.o
Minimum Eligible Age

18 Years

Maximum Eligible Age

45 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Stanford University

OTHER

Sponsor Role lead

Responsible Party

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Eric Gross

Assistant Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

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Stanford School of Medicine

Stanford, California, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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Eric Gross, MD/PhD

Role: CONTACT

Phone: (650)721-4521

Email: [email protected]

Facility Contacts

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Eric Gross, MD/PhD

Role: primary

Other Identifiers

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59978

Identifier Type: -

Identifier Source: org_study_id