A new test method may enhance the identification of adulterants in black cohosh products, and allay concerns over potential liver toxicity from the presence of other related herbal species in black cohosh formulations.
Black cohosh (Actaea racemosa L., syn. Cimicifuga racemosa L.) is a member of the buttercup family, and is a perennial plant native to North America. It has been a popular alternative to hormone replacement therapy (HRT) in many countries.
However, recent reports of liver toxicity related to black cohosh supplementation have raised questions about black cohosh safety. Subsequent evaluation (Health Canada, 2010 ) found some products contain related herbal species, but not black cohosh itself.
The new test method, published in Phytochemical Analysis, identified two important marker compounds, as well as fingerprints of constituent polyphenols and triterpene glycosides indicative of black cohosh.
“Correct plant species identification is a key first step for good manufacturing practices of safe black cohosh products,” explained the scientists from the City University of New York, Columbia University (New York), and Old Dominion University in Virginia.
Led by Ed Kennelly from the City University of New York, the researchers combined high-performance liquid chromatography (HPLC) equipped with a photodiode array (PDA) detector with liquid chromatography-mass spectrometry (LC-MS) techniques to analyze the pattern of polyphenols and triterpene glycosides in black cohosh, which were found to be “clearly distinguishable from most other species of Actaea”, they said.
Furthermore, the researchers identified two marker compounds – cimifugin and cimiracemoside F – as ways of differentiating between American and Asian species of Actaea.
Helpful for GMPS
“The combined LC-MS and HPLC-PDA method to distinguish black cohosh from related species is a robust means to help ensure the quality of black cohosh products,” report the researchers. “This is especially significant since black cohosh products adulterated with other species have been associated with mortality.
“Since it can be used not only for the determination of the quality of black cohosh products but also the identification of the possible adulterated Actaea species, the method we developed in this study would be very helpful for both the good manufacturing practices of black cohosh products and the better understanding of the safety of black cohosh,” they added.
Mark Blumenthal, founder & executive director of the American Botanical Council (ABC), welcomed the new paper, noting that it is one in a series from the research group of Ed Kennelley. Blumenthal described Kennelley’s group as “the leading team testing black cohosh and so-called "black cohosh" ingredients and products”.
“It is very timely and should be used by all companies purchasing herb material and extracts labeled ‘black cohosh’, ie, unless the company has either properly and adequately qualified that the black cohosh material has been wild-crafted in the US or grown in commercial cultivation in the US,” said Blumenthal.
“With so much evidence from previous testing and information we have from the market, it is essential that herb and dietary supplement companies adopt this robust and reliable method immediately, especially to ensure that materials labeled ‘black cohosh’ are not adulterant Actaea species from China,” he added.
Steven Dentali, PhD, chief science officer for the American Herbal Products Association (AHPA) told NutraIngredients-USA that the new test method is “highly technical and that simpler and less expensive techniques, such as HPTLC, have been shown to be suitable for this identity determination”.
According to AHPA’s 2006-2007 Tonnage Survey of Select North American Wild-Harvested Plants, despite a drop in harvest volumes of black cohosh in 2005, harvest levels for 2006 to 2007 returned to 2003-2004 levels, data that indicates the “sustained strong market for this commodity”.
Antoine Dauby, group marketing director for botanical extract supplier Naturex, also welcomed the new test, noting that the company considers “adulteration as a serious issue, which is likely to harm the legitimacy of our industry.
“We continually invest in developing new analytical methods. Furthermore, we also work closely with the American Botanical Council and the American Herbal Product Association to develop new analytical methods and to generate new standards,” he told NutraIngredients-USA.
Source: Phytochemical Analysis
Published online ahead of print, doi: 10.1002/pca.1285
“Phytochemical fingerprinting to thwart black cohosh adulteration: a 15 Actaea species analysis”
Authors: B. Jiang, C. Ma, T. Motley, F. Kronenberg, E.J. Kennelly