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Randomized Controlled Trial of Silymarin in Asthma

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01049178
Recruitment Status : Withdrawn (Lack of funding)
First Posted : January 14, 2010
Last Update Posted : February 24, 2014
Information provided by (Responsible Party):
Tina Hartert, Vanderbilt University

Brief Summary:
The purpose of this study is to determine if intake of the antioxidant enzyme inducer, silymarin, will improve lung function and symptom scores in participants with asthma.

Condition or disease Intervention/treatment Phase
Atopic Asthma Drug: Oral Silymarin Drug: Oral Silymarin, maintenance dose Drug: Placebo Phase 2 Phase 3

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 0 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Care Provider)
Primary Purpose: Treatment
Official Title: Antioxidant Enzyme Induction as a New Approach to Therapy in Patients With Asthma
Study Start Date : September 2010
Actual Primary Completion Date : September 2010
Actual Study Completion Date : September 2010

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Antioxidants Asthma
Drug Information available for: Silymarin

Arm Intervention/treatment
Experimental: Oral silymarin dose
Dose escalation study
Drug: Oral Silymarin
Dose Level 1: 1 capsules (1 cap at 140mg/cap) given three times per day for a total daily dose of 420 mg 28-days post Dose Level 1 Dose Level 2: 3 capsules (3 caps at 140mg/cap = 420 mg) given three times per day for a total daily dose of 1260 mg Day 56 (28-days post Dose Level 2) Dose Level 3: 5 capsules (5 caps at 140mg/cap = 700 mg) given three times per day for a total daily dose of 2100 mg Day 84 (28-days post Dose Level 3) We will evaluate change from baseline at each dose to determine the minimum effective dose.
Other Names:
  • Legalon
  • Milk Thistle

Drug: Oral Silymarin, maintenance dose
The maintenance Silymarin dose will be selected based on the dose escalation study and will be dosed PO three times daily as recommended. Silymarin will be provided as a capsule S. marianum (70-80% silymarin), along with an identical appearance placebo capsule created by our investigational pharmacyAt each visit a questionnaire regarding daily symptoms and disease control, the asthma control test (ACT) will be completed, eNO measured, urine collected, spirometry (lung function) measured, venipuncture performed for blood collection (20 mL), as well as assessment of acceptability, toxicity, and masking.
Other Names:
  • Legalon
  • Milk Thistle

Placebo Comparator: placebo
A randomized, double-masked, placebo-controlled cross-over clinical pilot investigation of an inducer of endogenous antioxidant enzymes, silymarin, in humans with atopic asthma.
Drug: Placebo

Primary Outcome Measures :
  1. Exhaled nitric oxide (eNO), an indirect measure of airway inflammation that correlates with clinical asthma measures. [ Time Frame: 20-40 weeks ]

Secondary Outcome Measures :
  1. Spirometry, disease control, urinary isoprostanes, antioxidant enzyme concentrations, silybin concentrations, acceptability, ability to maintain blinding, effect size for secondary clinical outcomes. [ Time Frame: 20-40 weeks ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Inclusion Criteria Male or female subject with confirmed asthma, AND
  • Age ≥ 18 years
  • Asthma Control Test (ACT) Score of 15-20, AND
  • Documented atopy by prick skin testing (most study participants will likely have participated in one of the investigators prior observational studies and will have had skin testing, if not, this will be performed at an in-person screening visit), AND
  • For women: Not pregnant, as determined by a negative urinary pregnancy test at the initial visit(visit 1), AND at the start of the cross-over period (visit 4), AND using birth control

Exclusion Criteria:

  • Known allergies to plants in the Asteraceae family (thistles, daisies, artichokes, kiwi)
  • Non-asthmatic, or inadequate documentation which includes lack of signs and symptoms of asthma, or lack of prior confirmatory testing
  • Pregnant
  • Age < 18 years
  • Non-English speaking
  • Current smoker (current, or within last year)
  • Chronic Obstructive Pulmonary Disease(COPD)
  • Unable to swallow capsules
  • Unable to obtain informed consent
  • Unable to comply with avoidance of honey and propolis containing foods (which interfere with the silybin assays for measurement of plasma concentrations)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01049178

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United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232-2650
Sponsors and Collaborators
Vanderbilt University
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Principal Investigator: Tina V. Hartert, MD, MPH Vanderbilt University Medical Center

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Responsible Party: Tina Hartert, Associate Professor of Medicine, Vanderbilt University Identifier: NCT01049178    
Other Study ID Numbers: IRB 090053
First Posted: January 14, 2010    Key Record Dates
Last Update Posted: February 24, 2014
Last Verified: February 2014
Keywords provided by Tina Hartert, Vanderbilt University:
antioxidant enzymes
Additional relevant MeSH terms:
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Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Lung Diseases
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs