Fluoride and metals in byrsonima crassifolia, a medicinal tree from the neotropical savannahs

Résumé 0

"The concentration of fluoride (F) in relation to mineral elements(K, Ca, Mg, Mn, Fe, Cu, Zn, Ni, Co, Cr, Al, Pb and Cd)and total phenols was evaluated in leaves of Byrsonimacrassifolia. Young, adult and fallen leaves were sampled in a gardenlocated outside an aluminium factory in Bolivar State, Venezuelaand in two sites in the savannah about 5 and 8km away fromthe Al-smelter in the direction of the wind. A positive linear regressionof F with Mn, Fe, Pb, Al, Ca, Mg, Cr and Zn was foundfor young and adult leaves. Leaves were sampled in two more distantsites (B1, B2) and in a contrasting site (M) at a region withoutAl mining or factories. In the vicinity of the smelter and in B1the content of F was high compared to the normal range inplants. The difference in concentrations of F, Fe, Al and Pb washighly significant by leaf age and site. In other species, a positivecorrelation of F to Al and total phenols, and a negative correlationto Ca has been reported, while in the present paper a positivecorrelation of F to Al, Ca and Fe, but not with total phenolswas found in B. crassifolia. The presence of metal-fluorine compoundsthat can be released during medicinal infusions has notbeen previously reported in this species. Washing the leaves withwater showed that a high proportion of F and minerals waspresent on the surface of the leaf and/or the trichomes."