Biogeochemical Aspects of Manganese Content in Ilex Paraguayensis SH from Paraguay by EDXRF and INAA

Abstract— Yerba mate, Ilex paraguayensis, is a plant of Paraguayan origin used in infusions/macerations by the ancient inhabitants of Paraguay as a “reviver”/energy beverage and mineral supplier which consumption is lasting up today; furthermore, it is extended almost worldwide. It has been recognized in Ilex paraguayensis, diuretic, CNS stimulant, hypocholesterolemic, hepatoprotective as well as other pharmacological properties. In regard to its elemental content few studies are known despite they play fundamental tasks in the structure and functioning of plants. One of them, Mn, usually occurs as a trace in Ilex paraguayensis, at relatively high concentration and in this work its concentration in plants from Paraguay have been investigated by EDXRF at Josef Stefan Institute at Ljubljana and at University of Asunción using radioactive isotopic sources and by INAA technique in the Faculty of Chemistry at Asunción with an Am-Be neutron source. These plants are grown mainly in two regions, north and south of Eastern Paraguay; results show that their manganese content can be used as a geochemical indicator to identify the region of origin. Besides, as in other plants, absorption, transport and homeostasis of Mn could be attributed to the action of different NRAMPs. In regard to its normal high content in healthy yerba plants, Mn in excess could be hidden in nodes and vacuoles being exported afterwards.