Dear Reader,The turmeric root/rhizome and root/rhizome extract Botanical
Adulteration Bulletin (BAB), issued in May 2018, is the 14th in the series of
bulletins published by the Botanical Adulterants Prevention Program (BAPP).
Turmeric is one of the most important spices, and also among the most popular
dietary supplement ingredients globally. The increased demand for turmeric
extracts and the improvement of laboratory analytical test methods have led to
new ways to adulterate the ingredient, such as the addition of
synthetically-made curcumin or curcuminoid mixtures. The turmeric bulletin assists
lab directors, quality control managers, and others in staying informed on
these challenges in order to adjust the identity testing protocols in quality
control laboratories.
In July, BAPP released the BAB on boswellia (Boswellia serrata) oleogum resin, and its extracts.
Boswellia dietary supplements have shown consistently high sales growth rates
over the past five years, and have been ranked the 22nd best-selling herbal
dietary supplement in the United States in 2017. The main issue regarding
boswellia authenticity is the substitution with oleogum resin extracts from
other Boswellia species. The BAB provides
boswellia manufacturers with a useful overview of the authenticity issues
surrounding the ingredient.
Reports on the adulteration of ginkgo dietary supplements
have received the attention of the Center for Science in the Public Interest
(CSPI), a “Food Watchdog” according to their website. Based on ConsumerLab’s
2018 ginkgo report and BAPP’s ginkgo leaf extract Botanical Adulterants Bulletin,
CSPI sent a letter to Steven Tave, Director of the Office of Dietary Supplement
Programs at the US Food and Drug Administration requesting more enforcement
action by the agency against adulterated ginkgo products. The letter also
questioned the efficacy and safety of ginkgo dietary supplements, in line with
a letter CSPI sent in 2013 to Michael Landa, then the Director of the Center
for Food Safety and Applied Nutrition (CFSAN), in which CSPI urged FDA to
remove all ginkgo products from retail shelves because a study showed that extended
ingestion of very high doses of ginkgo extracts had led to tumor growth in mice
and rats.1 A short review of CSPI’s letter and a brief comment on
the topic can be read in the Regulatory Alerts
section.
The results of a preliminary report on adulteration of
commercial ginkgo dietary supplements by researchers from Network
Nutrition-IMCD in Australia have been included in the previous issue of the Botanical Adulterants Monitor. The group has now summarized
the data in a “Ginkgo biloba Market Report,” and
made it available by request to interested parties. A note on the report and details
on how to access it is provided in the Industry Alert
section of this newsletter.
Summaries of six scientific papers can be found in the Science section. With the exception of the HPTLC paper on Angelica and related Apiaceae species, these papers all included analytical data on a fairly large number of commercial dietary supplement samples, ranging from nine to 53 products. The first summary details a particularly sophisticated means of
adulteration of saw palmetto, where fatty acids are blended together at the
same ratio found in authentic saw palmetto extracts. A combination of isotopic
fingerprinting, gas chromatography (GC), and nuclear magnetic resonance (NMR)
was used to assess nine commercial samples labeled to contain saw palmetto. Ten
commercial cranberry products from the French market were analyzed by high-performance
thin-layer chromatography (HPTLC) and ultra high-performance liquid
chromatography with mass spectrometric detection (UHPLC-MS). Since many of the
selected products contained additional plant extracts, the HPTLC fingerprints
were highly variable, complicating accurate determination of the presence of
cranberry in these dietary supplements. The HPLC-UV analysis of over 50
commercial ginkgo dietary supplements marketed in Europe, published by Czigle
et al., found quality issues in ca. 80% of the tested products, in agreement
with other recent publications on the quality and authenticity of ginkgo.2-4
A similarly large sample set (N = 53) of echinacea dietary supplement products
was evaluated by HPTLC and DNA metabarcoding. A vast majority of the products
(between 80-90%) contained echinacea as claimed on the label. With the goal to
harmonize analytical methods for the identification of medicinal plant members
of the family Apiaceae, Frommenwiler et al., developed an HPTLC method that can
be used for Angelica gigas and the roots of 26 other
Apiaceae species. The fingerprints of the roots of these species could be
distinguished using various detection reagents, suggesting that the method is
suitable for authentication of these materials. The last paper summarized in
this newsletter looked into the use of low field nuclear magnetic resonance (NMR)
to detect adulteration of patchouli essential oil. NMR proved to be a useful
tool for determination of admixture for most of the potential adulterants, but
not as useful as gas chromatography-mass spectrometry (GC-MS). Of the 10
commercial patchouli samples measured by NMR, four were found to be
adulterated.
We hope that the information included in this issue of
the Botanical Adulterants Monitor will be useful. Feel
free to circulate the information among your colleagues with the goal that the
information will help to avoid adulterated ingredients finding their way into the
supply chain for herbal dietary supplements and other finished botanical products.
Stefan Gafner, PhD
Chief Science Officer
American Botanical Council
Technical Director, ABC-AHP-NCNPR
Botanical Adulterants Program
References
- Jacobson MF, Schardt D (CSPI). Letter to Landa MM (USFDA). June 3, 2013. https://cspinet.org/sites/default/files/attachment/ginkgo-fda-letter-6-3-2013.pdf. Accessed June 6, 2018.
- Ma
Y-C, Mani A, Cai Y, et al. An effective identification and quantification
method for Ginkgo biloba flavonol glycosides with
targeted evaluation of adulterated products. Phytomedicine.
2016;23(4):377-387.
- Clear majority of European food supplements containing Ginkgo biloba extract found to be adulterated [white paper]. Bella Vista, NSW, Australia; Network Nutrition-IMCD; 2018.
- Avula B, Sagi S, Gafner S, Upton R, Wang YH, Wang M, Khan IA. Identification of Ginkgo biloba supplements adulteration using high performance thin layer chromatography and ultra high performance liquid chromatography-diode arrau detector quadrupole time of flight-mass spectometry. Anal bioanal Chem. 2015;407(25):7733-7746.