Neurobiology of Black Cohosh for Hot Flash Relief

Principal Investigator:

Nancy E. Reame, MSN, PhD
School of Nursing, University of Michigan

Co-Principal Investigator(s):

Yolanda Smith, MD, MS
Obstetrics & Gynecology, University of Michigan

Funding sources:

Pilot study- General Clinical Research Center (GCRC #2060)

Time period for subject recruitment (start/end dates):

January 2005- December 2005
Contact: Julie Chilimigras, jlc@umich.edu (734-936-3590).

For additional information:

http://www.nursing.umich.edu/research/studies.html

Objectives/aims of study:

Black cohosh is a dietary supplement made from plant roots that is sold "over-the-counter" in pill form and used to treat hot flashes in menopausal women. The purpose of this preliminary study is to determine how black cohosh acts on the brain to relieve hot flashes. We are testing the hypothesis that black cohosh imitates the effects of estrogen by activating the same biochemical pathway in the brain called the opioid system. To test this hypothesis, we will measure changes in the levels of luteinizing hormone (LH), during sleep before and after giving naloxone. LH is a reproductive hormone made in the pituitary that is controlled in part by the opioid system. Naloxone is a prescription medication that blocks the opioid system and is sometimes used to treat drug overdose. We will also perform PET scanning studies of the brain (one anatomical Magnetic Resonance Imaging (MRI) and 2 Positron Emission Tomography (PET) scans) on a subset of 5 volunteers to look for changes in the opioid system before and after black cohosh treatment. We already know how estrogen affects these two kinds of tests from our previous studies in women.

Design of study:

The study will consist of 6 visits to the General Clinical Research Center (GCRC) at the University of Michigan Hospital. The total amount of time you will be asked to participate in this study is approximately 4 months. This will involve three 1-hour outpatient visits and three 24-hour inpatient visits. Volunteers will receive black cohosh in the form of two tablets (20 mg each) per day for 12 weeks. A subset of five volunteers will undergo PET scanning (one MRI and two PET scans).

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