Analyzing field horsetail products on the market – identifying marsh horsetail impurities

Equisetum arvense L. (field horsetail) is a plant with variety of properties and uses mentioned in ethnomedicinal sources – diuretic, wound healing, hemostatic, antigout. The speciesʼ range of distribution in Bulgaria is throughout the country. Equisetum palustre L. (marsh horsetail) has similar macroscopic diagnostic characteristics and habitat. These similarities pose a threat of contamination of E. arvense products on the market and therefore to human health since E. palustre contains poisonous alkaloids – palustrine, palustridiene [1], [2].

The contamination with E. palustre in 19 products from the market and pharmacies in Bulgaria has been investigated. 15 of them (78,9%) are mono component, while the other 4 (21,1%) are herbal tea mixtures. Their identity and purity have been determined in three steps – 1. Macroscopic determination; 2. Microscopic determination; 3. Thin layer chromatography [3]. 4 (21,1%), 6 (31,6%) and 6 (31,6%) contaminated products have been identified by the respective analyses. Correlation has been found between the three analyses – same samples have been identified as contaminated by all the analyses. Combining the three methods has been proved beneficial in identifying impurities in the products.

The obtained results show the lack of strict enough control over gathering and identification of plant material used in the analyzed products on the market. Product safety and effectiveness may be decreased and a threat to the population that uses them may be present.

The authors are grateful to the financial support of Bulgarian NSF, Contract 2901/KP-06-China/15/2020.

The authors declare that they have no conflict of interest.

Publication History

Article published online:
12 December 2022

• References

• 1 Cramer L, Ernst L, Lubienski M. et al. Structural and quantitative analysis of Equisetum alkaloids. Phytochemistry 2015; 116: 269-282
• 2 Müller J, Puttich PM, Beuerle T. Variation of the main alkaloid content in Equisetum palustre L. in the light of its ontogeny. Toxins 2020; 12 (11) 710
• 3 European Pharmacopoeia 10.0, 1825 (04/2012).