College of Agriculture and Natural Resources, Shiraz University, Darab, Iran
The essential nutrients in the pharmacological plants play a significant role in the remedy of illnesses but, these elements at high levels; can also be dangerous and toxic. The aim of this study was to determine the concentration of macro (Mg, Ca, P, and K) and micro (Cu, Zn, Fe and Mn) essential elements in seven indigenous pharmacological plants growing in Fars Province, southern Iran. They were established using flame atomic absorption spectrophotometer (FAAS) and flame photometer. The results showed that there was very large variation in the element levels in studied medicinal plants. The studied medicinal plants contain appreciable quantity of K, P, Ca and Mg which are essential component of human nutrition. The highest concentration of Zn (50.7 mg kg-1 DM), Mn (1503.0 mg kg-1 DM) and Fe (1339.7 mg kg-1 DM) was found in Vitex pesedo-negundo. Verbascum thapsus had the highest concentration of Cu (23.0 mg kg-1 DM). Most of the detected values for all micro nutrients in studied medicinal plants were upper the WHO/FAO permissible levels and may cause a health hazard for consumers; thus, these medicinal plants should be used with more caution when taken orally or consumed as part of diet.