In vitro study of bioaccessibility of trace elements in herbal preparations: Preliminary report

The effectiveness of herbal medicines is traditionally associated with organic biologically active compounds, while their elemental composition and bioaccessibility of trace elements remain understudied. The aim of the current study was to evaluate the bioaccessibility of elements in in herbal medicinal drugs (as an example pectoral species No. 4) under conditions simulating human digestion. The objects were pectoral species No. 4 and its water extracts (infusions). The bioaccessibility of elements was assessed using a two-stage in vitro digestion model. The elements content was analyzed by ICP-MS after preliminary mineralization. For most essential elements, maximum bioaccessibility was observed in the gastric phase, with only three elements (Zn, Si, Mo) showing greater accessibility in the intestinal phase. The analysis identified the most accessible components of the herbal preparation - Cr, Si, Mo, and Co - which are characterized not only by effective extraction into an aqueous infusion, but also by consistently high availability (over 80%). In contrast, Zn and Cu, despite their good extractability, demonstrate a significantly lower level of bioaccessibility (15-30%). It was found that the bioaccessibility of elements significantly depends on their chemical nature and the stage of digestion, with most trace elements reaching maximum availability in the gastric phase. Therapy with pectoral species No. 4 replenishes up to 85% of the requirement for Cr. The new data obtained must be considered when prescribing herbal preparations to increase the effectiveness of therapy.