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."