The potentiality of vanadium in medicinal applications.

In the early treatment of diabetes with vanadium, inorganic vanadium compounds have been the focus of attention; organic vanadium compounds are nowadays increasingly attracting attention. A key compound is bis(maltolato)oxidovanadium, which became introduced into clinical tests Phase IIa. Organic ligands help modulate the bioavailability, transport and targeting mechanism of a vanadium compound. Commonly, however, the active onsite species is vanadyl (VO(2+)) or vanadate (H(2)VO(4) (-)), generated by biospeciation. The mode of operation can be ascribed to interaction of vanadate with phosphatases and kinases, and to modulation of the level of reactive oxygen species interfering with phosphatases and/or DNA. This operating mode has also been inferred for most cancerostatic vanadium compounds, although some, for example vanadocenes, may directly intercalate with DNA. Novel medicinal potentiality of vanadium compounds is geared towards endemic diseases in tropical countries, in particular leishmaniasis, Chagas' disease and amoebiasis, and viral infections such as Dengue fever, SARS and HIV.