Introduction: Nowadays, many people use medicinal plants to manage diseases; therefore, detailed knowledge of the type and level of elements present in these plants is of prominent importance.The present study aimed to determine the weight fraction of 12 elements in the five most common medicinal plants in Iran. The names of these plants are caraway (Carum carvi), savory (Satureja hortensis), purslane (Portulaca oleracea), fenugreek (Trigonella foenum-graecum), and milk thistle (Silybum marianum) which were purchased from herbal pharmacies. Material and Methods: The neutron activation method was used to determine the elements. In the current study, neutrons from the research reactor core in Tehran, Iran were used and gamma spectra from radionuclides were recorded using a high purity germanium detector. The mass fractions of 12 elements were determined in the five abovementioned plants. Results: Caraway had the maximum amounts of elements of Fe (8,789 ppm), Cr (8 ppm), and Na (517 ppm) among the selected plants. The savory contained maximum levels of Mn (95 ppm), Cl (3,702 ppm), Ca (18,328 ppm), K (21,562 ppm), and V (2.7 ppm) and the lowest amount of Fe (195 ppm), Zn (13 ppm), Ca (2,243 ppm), Al (99ppm), Mn (26 ppm), and Mg (177ppm) were observed in fenugreek. Conclusion: The highest levels of Cr and Mg were obtained for caraway (8 ppm) and pursalne (3,915 ppm), respectively. These elements can help to decrease blood cholesterol and triglyceride levels. Furthermore, the results showed that these herbs were rich in essential nutrients for metabolic functions.
