RESUMO
Medicinal plants have been used for treatment of many diseases since the ancient times with traditional knowledge being transferred from generation to generation. However, in recent years, many natural habitats have been contaminated due to increased anthropogenic activities. Plants which are exposed to heavy metal toxicity may experience several serious problems. Furthermore, the inclusion of these plants into the food chain poses a threat to human health as well. Additionally, presence of heavy metals directly effect mineral nutrition and consequently the food quality. The aim of this study herewith is to determine the heavy metal content and mineral nutrient status of some medicinal plants to have insight on their health repercussions on plants and humans. The concentrations of Al, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn in commonly used parts (root, rhizome, seed, resin, gall, fruit) especially for remedial purposes of 17 medicinal plants collected from Turkey were analyzed by ICP-OES. The measured values for concentrations from lowest to highest were (in mg kg-1) 30.983-368.877 for Al, 13.845-186.015 for B, 1335.699-11213.951 for Ca, 0.016-0.653 for Cd, 0.379-30.708 for Cr, 23.838-90.444 for Cu, 78.960-1228.845 for Fe, 1035.948-6393.491 for K, 83.193-2252.031 for Mg, 12.111-362.570 for Mn, 278.464-1968.775 for Na, 1.945-35.732 for Ni, 0.796-17.162 for Pb and 166.910-395.252 for Zn. Overall, heavy metal concentrations in medicinal plants collected nearby industrial regions, mining and farming sites, were found to be in slightly higher levels. This shows us that it is of crucial importance that the areas where medicinal plants are collected are clean especially by means of heavy metals for the reason that these plants can cause more harm than the benefits they may provide if they are contaminated.
