RESUMO
Vanadium compounds are known for a variety of pharmacological properties. Many of them display antitumoral and osteogenic effects in several cell lines. Free radicals induce the development of tumoral processes. Natural polyphenols such as flavonoids have antioxidant properties since they scavenge different free radicals. For these reasons it is interesting to investigate the effects of a new complex generated between the vanadyl(IV) cation and the flavonoid hesperidin. The complex has been synthesized and characterized by physicochemical methods. Spectroscopic analysis revealed a 1:1 stoichiometry of ligand:VO and coordination by deprotonated cis-hydroxyl groups to the disaccharide moiety of the ligand. The complex improves the superoxide dismutase (SOD)-like activity of the ligand, but the scavenging of other radicals tested does not change upon complexation. When tested on two tumoral cell lines in culture (one of them derived from a rat osteosarcoma UMR106 and the other from human colon adenocarcinoma Caco-2), the complex enhanced the antiproliferative effects of the free ligand, and this effect correlated with the morphological alterations toward apoptosis. Also, on the osteoblastic cell line the complex stimulated cell proliferation and collagen type I production at low concentrations. At higher doses the complex behaved as a cytotoxic compound for the osteoblasts.
Assuntos
Anticarcinógenos/farmacologia , Antioxidantes/farmacologia , Hesperidina/farmacologia , Neoplasias/prevenção & controle , Compostos de Vanádio/farmacologia , Fosfatase Alcalina/antagonistas & inibidores , Animais , Diferenciação Celular/efeitos dos fármacos , Divisão Celular , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Ratos , Espectrofotometria Infravermelho , Superóxido Dismutase/metabolismoRESUMO
The superoxide dismutase-mimetic activity and the electrochemical behavior of the binuclear complex [Cu(TSA)2py]2 is reported. The complex exhibits a marked SOD activity in the nitroblue tetrazolium assay. Its redox response is in agrement with two copper atoms partially coupled through the carboxylate moieties. The electrode reactions lie in the range of the superoxide/peroxide and oxygen/superoxide couples. This fact is indicative that this complex can act as catalyst for the SOD reaction.
