Botanical Adulterants Monitor: Issue 20, September 2020

Adulteration of European Elder Berry Extracts on the Rise

Herbal dietary supplement manufacturer Nature’s Way (Green Bay, WI) has shared data from their in-house investigation into the authenticity of commercial bulk and finished dietary supplement products labeled to contain European elder (Sambucus nigra, Adoxaceae)¹ berry extracts. Twenty-five bulk extracts and eight finished products were analyzed by high-performance thin-layer chromatography (HPTLC), high-performance liquid chromatography with visible detection (HPLC-Vis), and UV/Vis spectrophotometry. The latter assay was used solely to determine total anthocyanins in the products. Test methods were in accordance with those published in the United States Pharmacopeial (USP) monograph on European elder berry dry extract,² the HPTLC Association,³ and the Institute for Nutraceutical Advancement (INA).⁴

In parallel, the scientists analyzed possible adulterants, including blueberry (Vaccinium angustifolium, V. corymbosum, or V. pallidum, Ericaceae), black chokeberry (Aronia melanocarpa, Rosaceae), amaranth dye, and black rice (Oryza sativa, Poaceae) extract, among others, using the same methods. The identity was assessed by HPTLC, and by the HPLC anthocyanin profile. Criteria included an assessment of the intensity of cyanidin-3-O-sambubioside signal, and the presence of cyanidin-3-O-sambubioside-5-O-glucoside. Of the 25 bulk materials, 14 failed the identity test (very low amounts of cyanidin-3-O-sambubioside compared to other anthocyanins), and five were found to contain no elder berry extract at all. Black rice extract was found as an adulterant in at least two cases. Among the eight finished elder berry dietary supplements, two products were devoid of elder berry extract. One contained mainly a substance similar to oat bran, while the other was made of Vitamin C, and excipients. Both adulterated products were visually distinct from authentic elder berry products with a white or orange color, respectively.

Comment: With the recent increase in sales volumes of European elder berry dietary supplements in the United States and elsewhere, and shipment delays of authentic elder berry bulk ingredients due to the COVID-19 pandemic, manufacturers have experienced difficulties in obtaining high-quality elder berry bulk extracts. Not surprisingly, there are some fraudulent suppliers which sell adulterated ingredients, trying to take advantage of the use of non-specific quality control methods (e.g., UV-Vis) for identity testing by some companies in the herbal dietary supplement industry and even some companies without quality control systems. According to Travis Borchardt, Vice-President of Product Integrity and Compliance at Nature’s Way, elder berry adulteration is a relatively recent occurrence, and appears to be linked to the commercial success of the ingredient over the past 3-4 years, i.e., before the outbreak of the COVID-19 pandemic, although it is quite likely that the increase in its demand during the pandemic has resulted in even further attempts by unscrupulous suppliers to offer fraudulent material. Adulteration of elder berry extracts is readily detected using the HPTLC profile, or the HPLC-Vis anthocyanin fingerprint.

References

1. Sambucus nigra. Medicinal Plant Names Services. Kew, Richmond, United Kingdom. https://mpns.science.kew.org/mpns-portal/backToSearch?query=sambucus+nigra&filter=&fuzzy=false&nameType=all. Accessed August 28, 2020.
2. European elder berry dry extract. USP 43-NF 38. Rockville, MD: United States Pharmacopeial Convention; 2020:4978.
3. European elder flower (Sambucus nigra). HPTLC Association. https://www.hptlc-association.org/methods/methods.cfm. Accessed August 28, 2020.
4. Institute for Nutraceutical Advancement. Anthocyanin content in bilberry by pH-differential spectrophotometry. INA Method 116.000.