Popular Herbal Menopause Remedy Shows Strong Chemical Stability in New Study
Austin, Texas. A new study has shown that an 85-year-old specimen of black cohosh root still contains much of the naturally-occurring chemical compounds which are believed to contribute to the popular herb’s ability to reduce hot flashes and other symptoms in menopausal women.
In the study, conducted by researchers at The New York Botanical Garden (NYBG), Lehman College, City University of New York, and Columbia University, published in the latest issue of the internationally respected Journal of Ethnopharmacology, researchers took pieces of powdered black cohosh root that was collected 85 years ago by the famous plant explorer and physician Henry Hurd Rusby. The specimen has been a part of the public exhibits of The NYBG in Bronx, New York until the 1930’s when the powdered herbal material was placed in storage.
The sample of black cohosh was analyzed for its triterpene glycosidic and phenolic constituents — naturally occurring compounds thought to be responsible for the root’s medicinal activity. Tests were performed both qualitatively and quantitatively by sophisticated laboratory analysis using high-performance liquid chromatography-photodiode array detector (HPLC-PDA) and liquid chromatography-mass spectrophotometry (LC-MS).
A comparison of the specifically measured chemical constituents of the 85-year-old plant sample with those of a recently-collected sample showed similar profiles, confirming the stability of the older sample, despite its curation over the years under a variety of conditions. Quantitative analyses indicated that both plant samples have similar amounts of the four major triterpene glycosides, but the total amount of the six major phenolic constituents measured in the 85-year-old plant material is lower than the amount measured in the modern plant material. This difference may be due to the natural chemical variation of these compounds in plants from different geographical areas and/or from different harvest seasons, or there may have been degradation over time. Methanol extracts of the two plant materials were tested for their antioxidant activity in a laboratory, and both extracts showed similar antioxidant activity.
One of the researchers, Michael J. Balick, PhD, Director and Philecology Curator at the Institute for Economic Botany at The NYBG, stated that the results show the present value of historic 19th and 20th Century plant and other biological collections as reference standards and scientific vouchers at institutions such as The NYBG. He noted, “What our team has shown in this study is that, at least in the case of black cohosh, some key plant compounds that are commonly thought to have a very short shelf life of only a few years, actually lasted nearly a century, despite the fact that they were exposed to light, humidity and less than optimal storage conditions for decades. While many herb companies normally put a two to three year expiration date on their herbal supplements, this research suggests that some supplement ingredients might be active for many, many years beyond their expected shelf life. It is time to use this same technique to look at other herbal samples that were collected in the late 1800’s and early 1900’s that still exist in The New York Botanical Garden’s collections, and elsewhere, to investigate the stability of plant chemicals present in herbal medicines.”
According to another author of the study, Fredi Kronenberg, PhD, Director of the Rosenthal Center for Complementary and Alternative Medicine at Columbia University College of Physicians and Surgeons in New York, “By comparing the various biological activities of fresh and old samples and identifying the differences in chemical profiles as a guide to the relevant compounds, we may gain insight into the mechanism of action of herbal remedies.”
The phytochemical analysis was carried out in the laboratory of Edward J. Kennelly, Ph.D., Associate Professor and Chair, Department of Biological Sciences, Lehman College, City University of New York. Professor Kennelly noted, “It is fascinating to consider that a plant specimen almost a century old has a chemical composition almost identical to a modern sample. We are interested in looking at the chemistry of other samples in the Rusby Collection in the future.”
Another medicinal plant expert supports the results of this study. “Medicinal plant teaching collections from the last century, usually stored in sealed glass jars, represent not only a valuable visible reference, but also a treasure trove of unique compounds sequestered in certain plant parts,” said Prof Ara Der Marderosian, Professor of Pharmacognosy and Medicinal Chemistry at the University of the Sciences in Philadelphia. He noted that this is also true for many spices and numerous other medicinal plants.
Mark Blumenthal, founder and executive director of the nonprofit American Botanical Council, said, “This research supports what many scientists have known for a long time — that some herbs have biologically active compounds that are stable for many years. We have known this for the ginsenosides in Asian ginseng root and other compounds in other plants. Now we have confirmation that some of the key compounds in black cohosh do not break down over time. The results of this study are relevant to the final rules for good manufacturing practices (GMPs) that are expected soon from the Food and Drug Administration. These new regulations deal with expiration dates for herbal dietary supplement labels and how manufacturers determine the shelf life of these products.”
Black cohosh (Actaea racemosa, syn. Cimicifuga racemosa) is a traditional native American medicinal plant in the buttercup family (Ranunculaceae) that has become increasingly popular as the most widely-used natural alternative to hormone replacement therapy (HRT). The herb’s popularity with middle-aged women and gynecologists grew significantly after the summer of 2003 when a large-scale clinical trial on HRT was halted prematurely after evidence that HRT was responsible for an increase in cancer and cardiovascular disease in menopausal women. At least 13 clinical trials on black cohosh preparations support their safety and efficacy in treating menopause-related symptoms, including hot flashes, perspiration and mood swings, according to Gail Mahady, Research Assistant Professor of Medicinal Chemistry and Pharmacognosy at the University of Illinois at Chicago, who is researching black cohosh with funding from the National Institutes of Health. Black cohosh ranked eighth of all herbal supplements sold in mainstream retail outlets in 2004, according to data from Information Resources in Chicago. Total retail sales of black cohosh in all channels of trade are difficult to estimate, but may be as high as $76 million in 2003, a jump of about 28% in sales from the previous year, according to Nutrition Business Journal.
About the American Botanical Council
Established in 1988, the American Botanical Council (ABC) is the leading nonprofit, member-based international organization working to educate consumers, healthcare professionals, researchers, educators, industry, and the media on the safe and effective use of herbs and medicinal plant products. ABC is located on a 2.5 acre site in Austin, Texas where it publishes HerbalGram, a peer-reviewed quarterly journal. ABC is also the publisher of The ABC Clinical Guide to Herbs, a continuing education module and reference book, which contains extensive monographs on the safety and efficacy of 29 popular herbs. More information is available at www.herbalgram.org.
Jiang B, Yang H, Nuntanakorn P, Balick MJ, Kronenberg F, Kennelly EJ. The value of plant collections in ethnopharmacology: a case study of an 85-year-old black cohosh (Actaea racemosa L.) sample. J Ethnopharmacol. January 15, 2005;96(3):521–528. Epub November 23, 2004.