Studies of the Effectiveness of Bisphosphonate and Vanadium-Bisphosphonate Compounds In Vitro against Axenic Leishmania tarentolae

Leishmaniasis is a disease that is a significant problem for people, especially in tropical regions of the world. Current drug therapies to treat the disease are expensive, not very effective, and/or of significant side effects. A series of alkyl bisphosphonate compounds and one amino bisphosphonate compound, as well as alendronate and zoledronate, were tested as potential agents against Leishmania tarentolae. Also, two polyoxometalates (POMs) with nitrogen-containing bisphosphonate ligands, vanadium/alendronate (V-5(Ale)(2)) and vanadium/zoledronate (V-3(Zol)(3)), were tested against L. tarentolae and compared to the results of the alendronate and zoledronate ligands alone. Of the compounds evaluated in this study, the V-5(Ale)(2) and V-3(Zol)(3) complexes were most effective in inhibiting the growth of L. tarentolae. The V-5(Ale)(2) complex had a larger impact on cell growth than either alendronate or orthovanadate alone, whereas zoledronate itself has a significant effect on cell growth, which may contribute to the activity of the V-3(Zol)(3) complex.