Losartan and its interaction with copper(II): Biological effects

Losartan, the potassium salt of 2-n-butyl-4-chloro-5-hydroxymethyl-1-[(2′-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl]imidazol, is an efficient antihypertensive drug. The vibrational FTIR and Raman spectra of Losartan (its anionic and protonated forms) are discussed. In addition, the copper(II) complex of Losartan was obtained and characterized as a microcrystalline powder. The metal center is bound to the ligand through the nitrogen atoms of the tetrazolate moiety as determined by vibrational spectroscopy. The compound is a dimer with the metal centers in a tetragonal distorted environment but the presence of a monomeric impurity has been determined by EPR spectroscopy. The antioxidant properties of the complex (superoxide dismutase mimetic activity) and its effect on the proliferation and morphology of two osteoblast-like cells in culture are reported. The new compound exerted more toxic effects on tumoral cells than the copper(II) ion and Losartan.

Losartan potassium salt and its copper complex [Cu(Los)2(H2O)3]2 were tested in osteoblastic culture. It has been demonstrated that Losartan is harmless for normal and tumoral bone cells while the copper complex inhibited cell proliferation in a dose response manner. Besides, Losartan did not exert antioxidant properties or caused morphological alterations in the cells. On the contrary, its copper(II) complex produced strong morphological changes and exhibited moderate antioxidant behavior.Figure optionsDownload as PowerPoint slide