The American Botanical Council (ABC)’s Botanical Adulterants Prevention Program (BAPP) recently announced the publication of its bulletin on milk thistle fruit. Dietary supplements and herbal medicinal products containing extracts of milk thistle fruit are sought after by consumers due to evidence supporting their role in supporting liver health, and have consistently ranked among the 40 top-selling ingredient in U.S. natural and mainstream retail outlets over the several past decades.
 
The therapeutic compound in milk thistle fruit, silymarin, denotes a mixture of chemicals known as flavonolignans, whose standardization for milk thistle extracts are well defined in official monographs such as those published in European and U.S. pharmacopoeias.
 
“Milk thistle has become a popular phytomedicine and herbal dietary supplement in the past decades due to its clinical documentation of safety and beneficial activity, mainly by people who are using it to improve and/or maintain liver health,” Mark Blumenthal, ABC founder and executive director and director of BAPP, said. “In some cases, people with compromised liver function might continue to experience liver problems if the milk thistle product they are taking contains adulterated material, particularly when all or most of the primary beneficial compounds have been removed.”
 
Peer-reviewed publications have shown that the silymarin content in some commercial dietary supplements is much lower than the amounts claimed on product labels. To some extent, such discrepancies can be explained by the use of different analytical methods, such as the use of high-performance liquid chromatography with UV detection rather than spectrophotometric methods. However, ABC reports that all publications to date point to the market occurrence of fraudulent products where silymarin has been reduced or removed without the knowledge of the buyer.
 
The new bulletin was written by Allison McCutcheon, PhD, an expert in herbal medicine research in Vancouver, British Columbia. It summarizes the published data on quality issues with milk thistle extracts, details analytical methods to detect adulteration, and informs on the nomenclature, production, and market importance of milk thistle extracts. During the peer-review process, 27 medicinal plant experts from academia, government, contract laboratories, analytical equipment manufacturers, and the botanical supplement industry have provided input on the bulletin.
 
“This is the first BAPP adulteration bulletin that focuses on the sale of depleted extracts, in which beneficial constituents are knowingly removed from concentrated standardized extracts, and the remaining botanical material is resold without declaring that important, therapeutically-active plant chemicals are absent, or present at very low concentrations,” Stefan Gafner, PhD, chief science officer for ABC and technical director of BAPP, said. “Such practices are known to occur in the spice industry, for example with black pepper, from which the pungent compounds are sometimes extracted and sold to the flavor industry, while the extracted peppercorns are dried, mixed with genuine peppercorns, and sold to the spice industry simply as ‘black pepper.’”
 
Similarly, extracted silymarin complex can be sold at higher prices to the phytomedicinal and dietary supplement industries – leftover fruits might be re-extracted, and those depleted extracts or fruits might be misrepresented as genuine to unsuspecting buyers, Gafner warned.
 
The goal of BAPP bulletins is to provide accounts of ongoing issues related to botanical identity and adulteration, and to provide confirmation of suspected or alleged adulteration of botanical raw materials, extracts, and essential oils, as well as fungal preparations, to allow quality control personnel and lab technicians in the field where these products are used to be informed on adulteration problems that appear to be widespread and may have safety concerns. The milk thistle bulletin is the 22^nd of its kind, and is the 61^st peer-reviewed BAPP publication, all of which are freely accessible to everyone.