RESUMO
Two species of perennial Phyllanthus (Euphorbiaceae) (Phyllanthus orbicularis and Phyllanthus discolor, both endemic to ultramafic areas of Cuba, and their natural hybrid, Phyllanthus xpallidus) were selected for metal localization microanalysis. Different plant tissues were analyzed by X-ray fluorescence, inductively coupled plasma-atomic emission spectroscopy, and scanning electron microscopy coupled with an energy-dispersive X-ray probe. All of the studied taxa are nickel (Ni) hyperaccumulators and significant concentrations of this element were found in different leaf and stem tissues. The highest Ni content was found in the laticifer tubes, whereas leaf epidermis Ni content resulted to be much more relevant in terms of total metal storage. Calcium and magnesium were found more evenly distributed in leaf and stem tissues.
Assuntos
Euphorbiaceae/metabolismo , Níquel/metabolismo , Solo , Álcalis , Cuba , Euphorbiaceae/ultraestrutura , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de VarreduraRESUMO
The chemical composition, pharmacological activity and traditional uses of 52 species attributed to the genus Lippia (Verbenaceae) as used in the South and Central America, and Tropical Africa, were revised and compared. A survey of the available literature shows that these species are used mostly for the treatment of gastrointestinal and respiratory disorders and as seasoning. Additionally, some of these Lippia species showed antimalarial, spasmolitic, sedative, hypotensive and, anti-inflammatory activities. Generally, the essential oil or the phenolic compounds (flavonoids) from these plant extracts are assumed to be the active principles.