When we brew chamomile or prepare motherwort tincture, we rarely think: what else besides useful substances could get into the cup? It turns out that heavy metals from polluted soil can be converted into medicines along with useful substances. The content of toxic elements (heavy metals) in plant raw materials used for the production of medicines is strictly controlled by the State Pharmacopoeia. However, the current regulations are based on an analysis of the gross (total) content of the element contained in the plant, without taking into account its actual availability. It is assumed that 100% of the metal found in the raw material will be converted into a decoction or tincture, which is not true.

In this regard, scientists from the Southern Federal University, together with colleagues from the Institute of Soil Science and Agrochemistry of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk), proposed a new approach to determining the permissible content of heavy metals in plant raw materials, taking into account the degree of transition of elements into various types of medicines. This approach will not only improve existing standards, but also expand the understanding of the nature of the accumulation of chemical elements by plants.

To obtain accurate data, scientists conducted large-scale studies in two key regions: in the agroecosystems of the Northern Azov region and in the forest-steppe zone of Western Siberia. Samples of soils and popular medicinal plants were taken here. Laboratory experiments, during which the process of preparing infusions and decoctions was modeled, showed that no more than 25-30% of the total laboratory-determined heavy metal content passes into the finished dosage form. Thus, current regulations may overestimate the potential risk to consumers by 3-4 times, which leads to a paradoxical situation: safe raw materials may be rejected, and the assessment of what is really dangerous may not be strict enough.

To solve this problem, scientists propose a fundamentally different approach: instead of measuring the gross content of an element, evaluate its bioavailable form — that specific fraction that is chemically capable of converting from plant raw materials into a medicinal product. This approach takes into account the chemical bonding of metals in plant tissues and their ability to be extracted during drug production, which gives a much more accurate picture of the real risk.

"As part of the project, we have expanded the monitoring areas, plan to compile geobotanical maps of the distribution of medicinal plants, and studied the effect of heavy metal pollution on pollen allergenicity of some wild plant species. The information obtained will allow us to better understand the patterns of accumulation and biogenic migration of chemical elements in the biosphere, as well as improve existing approaches to assessing potential risks associated with the manufacture of medicines," said Viktor Chaplygin, a leading researcher at the SFedU Academy of Biology and Medicine, Candidate of Biological Sciences.

This research was supported by the Russian Science Foundation (project No. 22-77-10097 at Southern Federal University), and was extended in 2025. As part of this project, scientific articles have been published in leading Russian and international journals. Among them are Environmental Science and Pollution Research and Eurasian Soil Science (Soil Science), the journal Regional Geosystems and Biodegradation.

As a participant of the strategic academic leadership program "Priority 2030" (national project "Youth and Children"), Southern Federal University focuses on solving the tasks of scientific and technological development of the country. As part of this work, the university creates full-cycle production and technological chains based on the network architecture of interaction to respond to "big challenges". The key areas of development cover a number of critical and end-to-end technologies that underlie three key strategic technological projects of the university: "Technologies of soil bioengineering", "Technologies of multifunctional microelectronics and intelligent sensors for biohybrid and cyberphysical systems" and "Technologies for accelerated development and transfer of strategically important materials in micro and low-tonnage production".

Southern Federal University, being a participant of the strategic academic leadership program "Priority 2030" (national project "Youth and Children"), concentrates efforts on solving the tasks of scientific and technological development of the country. As part of this work, the university creates full-cycle production and technological chains based on the network architecture of interaction to respond to "big challenges". The key areas of development cover a number of critical and end-to-end technologies that underlie three key strategic technological projects of the university: "Technologies of soil bioengineering", "Technologies of multifunctional microelectronics and intelligent sensors for biohybrid and cyberphysical systems" and "Technologies for accelerated development and transfer of strategically important materials in micro and low-tonnage production".