Levels of Toxic and Essential Elements in Medicinal Herbs Commercialized in Argentina

The consumption of medicinal herbs, in the form of infusions, such as chamomile (Matricaria chamomilla), rosemary (Rosmarinus officinalis), wormwood (Artemisia absinthium), mint (Mentha piperita) and muña-muña (Clinopodium gilliesii) is widespread in the region. The determination of toxic and essential elements is relevant to evaluate their incorporation into the human organism. Although the study of elemental levels in different herbs and their infusions is quite widespread, information on plants from Argentina is scarce. In the present work, Cd, Pb, As, Fe, Cu, Ca, Mg, Na and K were quantified in the five commercially available medicinal herbs and in their infusions by atomic absorption and emission spectrometry. In general, the nutrient levels obtained in the herbs studied followed the sequence: K > Ca > Mg > Fe > Na > Cu while in the infusions the order was: K > Mg > Na > Ca > Fe > Cu. Pb was found in the chamomile and wormwood infusions at levels below 10 µg.L-1, whereas Cd and As were not detected (LOD= 0.07 μg.L-1 and 7 μg.L-1 respectively). The estimated daily intake (EDI) values calculated for the essential elements in the infusions were lower than the recommended daily intake (RDI) levels suggested by the World Health Organization (WHO) and did not provide the diet with significant nutritional values. As for to the toxic elements Pb, Cd and As, the EDI values obtained in the infusions were below the provisional maximum tolerable daily intake (PMTDI), indicating that they do not entail a health risk.