ABC updates black cohosh adulteration with new bulletin

The bulletin, which part of the ABC-AHP-NCNPR Botanical Adulterants Program​, pulls together a wealth of material that ABC and its partners have previously generated on black cohosh, said ABC executive director Mark Blumenthal.

“We’ve taken all that data that we’ve previously published and put it into this standardized format,” ​Blumenthal said.

Liver toxicity worries​

The program, which is in conducted in partnership with the American Herbal Pharmacopoeia and the Nation Center for Natural Products Research at the University of Mississippi, has published five previous bulletins on adulteration of various botanicals. The black cohosh edition stands out in that with this particular botanical the stakes for accidental or deliberate adulteration are higher than for some other herbs. In some cases, liver toxicity has been associated with  black cohosh adulteration. The botanical is known chiefly for its positive effects on symptoms of menopause.

“There have been some black cohosh-associated cases of liver toxicity. USP back in the mid 2000s did a review of these cases and found that there was no evidence that black cohosh itself is hepatotoxic, but rather that these were cases related to the use of Chinese actaea, which is a related species,” ​Blumenthal said.

“There were three acute cases in Canada, one of which required a liver transplant. All three were associated with the Chinese species,”​ he said.

Blumenthal said that more information on the precise mechanism of the hepatotoxicity in these cases would be helpful. The Chinese species have been used for years in TCM preparations, apparently without toxic effects, so it’s unclear what is going on with the adulterated ingredients. In any case, making sure that a black cohosh supplement contains material from Actaea racemosa​ and no other species is a solution to that problem, and the bulletin aims to make that easier for companies to ensure.

Stefan Gafner, PhD, ABC chief science officer and Botanical Adulterants Program technical director, who wrote the Black Cohosh Bulletin, commented, “Adulteration of black cohosh continues to be a problem. Since the publication of Foster’s ​HerbalGram review on black cohosh adulteration and the Laboratory Guidance Document last year, new studies have confirmed the illegal substitution of botanical material labeled as ‘black cohosh’ with closely-related Asian plants; however, these Asian species are different from authentic North American black cohosh. The goal of this new Bulletin is to further increase awareness of black cohosh adulteration.”​

Shrinking habitat​

Black cohosh is native to North America, and most of the ingredients in the market are wild-crafted in Appalachia. As with other wild-crafted herbs, habitat loss is a concern for future supplies, making substitution a growing threat. There is a small amount of the botanical that is cultivated in Europe, notably by German company Schaper & Brümmer. In the most recent harvest data available, released by the American Herbal Products Association in 2012, 142 metric tons of the botanical came from wild-crafted sources, with an additional 4.5 metric tons coming from cultivated fields.

The bulletin states that the data on possible adulteration is small scale and thus should be taken with a grain of salt.  Combining the data from five smaller studies shows that of 92 finished products analyzed, about 27% contained material not exclusively from Actaea racemosa​.  The bulletin includes a discussion of HPTLC methods as outlined by the European Pharmacopoeia and the United States Pharmacopeia as being suitable analytical methods for determining adulteration. DNA testing may also be appropriate in cases where whole plant material with intact DNA is present.