Safety, Metabolism, and Antioxidant Activity of Silymarin and Green Tea Extract in Patients With Chronic Hepatitis C

April 15, 2017 updated by: University of North Carolina, Chapel Hill

Steady-State Pharmacokinetic Interactions of Green Tea Catechins and Silymarin Flavonolignans in Treatment Naïve Patients With Chronic Hepatitis C Infection

The purpose of this study is to determine if the safety, metabolism, and antioxidant activity of silymarin and green tea extract are changed when they are given in combination to patients with chronic hepatitis C infection.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Silymarin and green tea are the two most widely used botanical products used by patients with chronic hepatitis C virus (HCV) infection. A major limitation of prior clinical investigations that may account for lack of efficacy is their use of inadequate customary oral dose regimens. Ongoing Phase II studies utilizing higher than customary doses of silymarin are based on potential disease modifying effects resulting from the potent antioxidant properties of silymarin flavonolignans. Since patients often use more than one herbal product to self-treat their disease, the use of higher than customary doses of silymarin may change silymarin's potential for herbal-herbal interactions. Pharmacokinetic interactions between silymarin and green tea catechins may change their safety/tolerability profiles, and may increase their antioxidant effects through additive or synergistic pharmacodynamic interactions. The objective of this double blind, active placebo controlled, randomized clinical trial is to characterize the pharmacokinetics and to evaluate the safety, tolerability, and antioxidant effects of an herbal cocktail consisting of silymarin and epigallocatechin gallate (EGCG) standardized green tea extract in treatment-naïve patients with chronic HCV infection. This investigation will include two treatment arms that will enroll 15 subjects per arm. Subjects will be randomized to receive in a fixed sequence either: 1) 196.5 mg EGCG followed by the coadministration of 700 mg silymarin; or 2) 700 mg silymarin followed by the coadministration of 196.5 mg EGCG. Each dosing regimen will be administered p.o. every 12 hrs for 12 days. No treatment arm uses high doses for both silymarin and EGCG in a sequence. Depending on the treatment arm, pharmacokinetic studies will be performed on plasma concentrations for six major silymarin flavonolignans and for the green tea catechin, EGCG at the end of 12 days of either silymarin or green tea extract monotherapy (Period 1), and then again after 12 days of silymarin and green tea extract given in combination (Period 2). For each treatment arm, plasma 8F2α-isoprostane concentrations, a measure of oxidative stress, will also be determined at baseline, during each period, and then at follow-up. The results from this investigation will be used to identify doses of silymarin and green tea that can be used together safely for future efficacy trials in patients with different chronic liver diseases.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
28

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27514
        • University of North Carolina at Chapel Hill- UNC Health Care

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Subjects will be eligible for enrollment in this study if they meet the following criteria:

  • Males or females; age at least 18 years at screening
  • Negative urine pregnancy test (for women of childbearing potential) documented within the 24-hour period prior to the first dose of silymarin. Females of childbearing potential must be using two reliable forms of effective contraception during the study (while on drug and during follow-up)
  • Hepatitis C virus (HCV) patients
  • Any HCV genotype
  • Never been treated or received less than 50% of standard peg-interferon-based therapy.
  • No interferon-based therapy in the previous 6 months
  • Serum HCV RNA above quantifiable level of detection by the assay, within 1 year of screening.
  • Before entering the study, subjects must agree not to consume alcohol for 48 hours prior to PK sampling days or while on study.

Exclusion Criteria:

Subjects with any of the following will not be eligible for participation:

  • Use of other milk thistle or green tea preparations within 30 days of Study Visit 1 (Day 1)
  • Use of other antioxidants such as vitamin E, vitamin C, glutathione, alpha-tocopherol, within 30 days of Study Visit 1 (Day 1). A multivitamin at standard doses will be allowed.
  • Use of diets containing > 6 servings per day, or 4-6 servings per day from > 8 of the vegetables and fruits listed in Appendix 2.
  • Allergy/sensitivity to milk thistle, green tea or their preparations
  • Inability to tolerate milk products (lactose intolerant)
  • Use of any interferon-based therapy in the last 6 months.
  • Use of warfarin, metronidazole or chronic use of acetaminophen greater than two grams per day
  • Previous liver biopsy that demonstrated presence of cirrhosis or previous liver biopsy that demonstrated greater than or equal to 15% steatosis or evidence of steatohepatitis
  • Positive test for anti-HIV or HBsAg within 3 years of screening
  • Positive urine drug screen for drugs of abuse at screening
  • Alcohol consumption of more than one drink or equivalent (>12 grams) per day. Patients who consumed more than this in the past must have maintained a level 12 grams or less per day of alcohol consumption for at least six months prior to screening.
  • History of other chronic liver disease, including metabolic diseases, documented by appropriate test(s)
  • Women with ongoing pregnancy or breast-feeding, or contemplating pregnancy
  • Platelet count <130,000 cells/mm3.
  • Creatinine clearance ≤30cc/min or currently on dialysis. Creatinine clearance will be calculated according to Cockcroft-Gault.
  • Evidence of alcohol or drug abuse within 6 months prior to screening
  • Evidence of decompensated liver disease defined as any of the following: serum albumin <3.2 g/dl, total bilirubin > 1.5 mg/dl, or PT/INR > 1.3 times normal at screening, or history or presence of ascites or encephalopathy, or bleeding from esophageal varices
  • History of inflammatory bowel disease or autoimmune hepatitis
  • History of solid organ or bone marrow transplantation
  • History of thyroid disease poorly controlled on prescribed medications
  • Use of oral steroids within 30 days prior to screening
  • Concurrent medications that are CYP3A4 inducers
  • Inability or unwillingness to provide informed consent or abide by the study protocol

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: low dose silymarin and low dose EGCG
Drug: silymarin
capsules, 700 mg, twice daily, 12 days
Other Names:
  • milk thistle
Dietary supplement: green tea extract (EGCG)
capsules, 196.5 mg, twice daily, 12 days
Other Names:
  • EGCG
  • green tea catechins
Experimental: high dose silymarin and low dose EGCG
Drug: silymarin
capsules, 700 mg, twice daily, 12 days
Other Names:
  • milk thistle
Dietary supplement: green tea extract (EGCG)
capsules, 196.5 mg, twice daily, 12 days
Other Names:
  • EGCG
  • green tea catechins

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
To assess the safety and tolerability of coadministered silymarin and green tea extract at different doses in patients with chronic hepatitis C.
Time Frame: November 2009 to September 2012
November 2009 to September 2012

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
To characterize the antioxidant effects of silymarin and EGCG administered alone or in combination.
Time Frame: November 2009 to September 2012
November 2009 to September 2012

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of North Carolina, Chapel Hill

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institutes of Health (NIH)
National Center for Complementary and Integrative Health (NCCIH)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Roy L Hawke, PhD, PharmD, UNC School of Pharmacy
  • Study Chair: Michael W Fried, MD, University of North Carolina, Chapel Hill

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2009

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2013

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2013

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 20, 2009

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 20, 2009

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 23, 2009

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 18, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 15, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 08-1631
  • R21AT003892-01A2 (U.S. NIH Grant/Contract)
  • CTRC-2779 (Other Identifier: University of North Carolinat at Chapel Hill)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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