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Motley Helps to Develop Safety Test for Black Cohosh Supplement

Motley (left) and Kennelly on black cohosh hunt in New York state.

Dietary supplements made of the perennial black cohosh plant, which are often used to relieve menopausal symptoms, should become purer and safer thanks to the work of a team of researchers including Timothy Motley of Old Dominion University.

Questions have been raised about the safety of black cohosh products because some people who reported taking them have suffered liver damage. Subsequent studies have found black cohosh products that are adulterated with other Chinese herbal species. Many of the adulterating plants are in the genus Actaea together with black cohosh and can be similar in appearance. But they are chemically different.

Motley, together with Ed Kennelly from the City University of New York and several other collaborators, have identified compounds found only in black cohosh (Actaea racemosa) and developed a test to distinguish A. racemosa from other species.

"The popular use of black cohosh products is growing as the demand for alternatives to estrogen therapy has increased," the scientists wrote in an article published by Phytochemical Analysis. "Critical to safe use is the assurance of unadulterated, high-quality products. Correct plant species identification is a key first step for good manufacturing practices of safe black cohosh products."

The title of the article is "Phytochemical Fingerprinting to Thwart Black Cohosh Adulterations: a 15 Actaea Species Analysis." Other authors are from City University of New York and the Rosenthal Center for Complementary and Alternative Medicine of Columbia University's College of Physicians and Surgeons.

Motley, who is the J. Robert Stiffler Distinguished Professor in Botany and Horticulture at ODU, has worked with Kennelly in recent years on research sponsored by the National Institutes of Health (NIH) to do DNA and phytochemical fingerprinting of black cohosh. The plant, one of the top 10 most widely sold herbals in the United States, has long been used for medicinal purposes by American Indians and is widely marketed now as a natural alternative to hormone therapy to treat menopausal women. The research has included DNA testing by Motley to help differentiate therapeutic black cohosh from its poisonous relatives.

The NIH project led Motley and Kennelly to China, where they are working on another research initiative to do fingerprinting of plants, including close relatives of black cohosh.

The rhizome - the rootlike subterranean stem - of black cohosh, a plant native to the northeastern United States and southeastern Canada, is used to produce the dietary supplements. The plant was harvested in the past by the Iroquois, Cherokee and Algonquian tribes to treat several ailments. By the end of the 19th century Europeans had discovered its use as a treatment for menopausal symptoms.

Market supplies are primarily collected from natural populations, although cultivation efforts are under way. Harvesting rhizomes from wild populations can result in the misidentification and over collection of plants, Motley said.

The article by Motley and his collaborators has been the subject of news reports from the American Botanical Council and the Nutra Ingredients website.

Motley and Kennelly's work in China also includes efforts to do DNA and chemical fingerprinting of ginseng, artemisia and astragalus.

This article was posted on: April 10, 2011

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