Assessment of heavy metals and macromineral in frequently used medicinal plants from Algerian Sahara traditional ethnopharmacopeia.

In this study, a total of 15 elements, both physiological and causing toxic effects, have been determined in 9 medicinal plants collected from their natural environment in the Algerian Sahara regions. The concentrations of elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) after acid digestion and by the X-ray fluorescence spectrometry (XRF). By analyzing the spiked test and the reference materials, the accuracy of the measurements was determined. Our findings show differences in elements composition and concentration between the species under investigation, indicating differences in physiological function of the plant as a result of elemental interactions within it. The elements were quantified (in μg/g): Br (0.04-5.44), Cd (1.21-1.34), Co (1.12-64.35), Cr (1.51-59.05), Cu (1.81-9.28), Fe (94.26-668.55), Mn (16.34-70.77), Ni (1.5-53.64), Pb (1.18-2.55), Zn (1.21-310.80) and (in mg/g): Ca (4.23-4.70), Cl (21.98-117.91), P (28.92-30.49), S (4.15-11.95), Si (1.99-2.36). Mean element levels in medicinal plants were established in decreasing order as follows: Zn>Mn>Cu>Cr>Ni>Pb>Cd>Co. Except for nickel, which reached 53.64μg/g in the Capparis spinosa L species, heavy metal concentrations were found to be low in all samples. Based on traditional use, we can cautiously conclude that these medicinal plants pose no risk to users.