Profile of Heavy Metal and Nutrient Elements in Some Sideritis Species

Background: Medicinal plants are the basic raw material of various herbal formulations in folk medicine in all over the world. In recent years, regarding quality and safety of plant materials collected from different ecological conditions, there has been a growing worldwide interest in monitoring heavy metal contamination and its effect on plant growth and nutrient uptake in medicinal and aromatic plants. Objectives: In this study, profile of heavy metal and selected nutrient elements (Al, Cd, Co, Cr, Ni, P, K, Ca, S, Fe, Cu, Zn, Mn, B and Na) of three Sideritis species (Sideritis germanicopolitana BORNM, Sideritis galatica BORNM and Sideritis hispida P.H. DAVIS) endemic to Turkey were determined using standard analytical methods. Methods: A scanning ICP–OES (Varian Vista-Pro, Australia) with high-resolution nitrogen purged with 1 m monochromator was used. Al, Cd, Co, Ni, Cr, P, S, K, Ca, Cu, Fe, Mn, B, Zn and Na contents were determined using ICP-OES. Results: The heavy metal and nutrient element concentrations in the Sideritis species were found rather different. Among the three species, Sideritis germanicopolitana showed considerable variation in nutrient concentrations and it was especially rich in iron (365 mg kg-1) and potassium (2.05 %). The heavy metal concentrations of all Sideritis species, on the other hand, were found to be lower than the permissible limits set aside for human consumption with no health risk in medicinal plants. Conclusions: Sideritis species growing wild in Turkey may be considered to be a crucial source of some nutrients like iron and potassium for human nutrition.