A curious case of dietary supplement adulteration: Cyanotis arachnoidea as fake spinach on the European market

Abstract

Phytoecdysteroids (PEs) are known to exert a non-hormonal, mild anabolic and adaptogenic activity in mammals [1], which makes ecdysteroid-rich plant extracts and purified 20-hydroxyecdysone (20E) attractive food supplements. A well-known European vegetable containing relatively low amounts of ecdysteroids is spinach [2,3]. Cyanotis arachnoidea (C. a.), a plant native in China, is among the richest sources of PEs. Several companies from the Far-East offer tons per year amounts of C. a. extracts via Internet at highly competitive prices. This plant, however, is considered a “novel food” within the EU, which is a serious limitation to the free marketing of its preparations. By using various chromatographic and spectroscopic methods, we found that a series of food supplements produced in Germany and marketed as “spinach-extracts” in fact contained C. a. instead of spinach. From one of these products, 13 ecdysteroids (20E and its 2- and 3-acetate, ajugasterone C and its 2- and 3-acetates, shidasterone and its 2-acetate, dacryhainansterone, rubrosterone, 5α-20E, and 25R- and 25S-podecdysone C) were isolated. The products' chromatographic fingerprints showed very high similarity to those of two independently purchased samples of commercial C. a. extracts, while displaying fundamental differences to the composition of a European spinach extract prepared by us. This case represents an unusual type of dietary supplement counterfeiting: the alleged pharmacological activities are supposedly enhanced by the addition of undeclared extracts from alternative plants that contain higher amounts of the same active ingredient(s). Although this is to “guarantee” product efficacy, the basic requirements of European dietary supplement regulations (correct declaration of composition, dosage, safety, etc.) are obviously violated.