The natural herb black cohosh is commonly used by women to treat menopausal symptoms such as hot flashes, but the molecular mechanisms underlying its action have eluded scientists -- until now.

Researchers at the University of Illinois at Chicago and the National Institutes of Health Center for Botanical Dietary Supplements Research have discovered that black cohosh may act on human opiate receptors, which play a role in regulating a body's temperature.

Z. Jim Wang, assistant professor of pharmacology and pharmaceutics, led the study, which will be published in an upcoming issue of the Journal of Agricultural and Food Chemistry; the paper is currently available on the journal's web site.

Opiate receptors are chemical sensors that respond to opiates like morphine and endorphins, Wang said. Chemical substances with opiate activity bind to the receptors and produce the appropriate response, including the regulation of pain, temperature and appetite.

"We used several extracts of black cohosh and found that elements of the herb could bind to the human 'mu' opiate receptor," Wang said. "The opiate receptor system affects several aspects of female reproductive neuroendocrinology, such as the levels of sex hormones and neurotransmitters that are important for temperature regulation."

Black cohosh (known as both Actaea racemosa and Cimicifuga racemosa) is a member of the buttercup family. A perennial plant, it is native to North America. It has been used by Native Americans to treat malaise, gynecological disorders, kidney ailments, malaria, rheumatism and sore throat, as well as colds, cough, constipation, hives and backaches, and to induce lactation.

Women experience a variety of symptoms of menopause, but the hot flash is the most common. Although the exact mechanism of the hot flash is unclear, estrogen withdrawal during menopause clearly plays an important role, Wang said. It is assumed that declining
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Contact: Sam Hostettler
samhos@uic.edu
312-355-2522
University of Illinois at Chicago
21-Dec-2006