Oxovanadium(IV) Complexes with Flavonoids. Potential Antitumoral Actions

LEON I.E.; MUGLIA C.I.; DI VIRGILIO A.L.; BARRIO D.A.; NASO L.G.; WILLIAMS P.A.M.; ETCHEVERRY S.B.

Simposio; V8 International Vanadium Symposium; 2012

The family of polyphenolic flavonoids includes monomeric flavanols, flavanones, anthocyanidins and flavones and their biological and medicinal properties are well known. They present estrogenic, antiallergenic, antiviral, antiinflammatory, vasodilating and antitumoral effects. This wide pharmacological activity depends mainly on the flavonoid structure. All these compounds have the 2-phenylbenzo-c-pyrone (C6O3C6) skeleton. In particular, Chrysin, 5,7-dihydroxy-2-phenyl-4H-chromen-4- one is a naturally occurring flavone. Like other members of this group, Chrysin is insoluble in water. On the other hand, Silibinin, or silybin (3,5,7-trihydroxy-2-[3-(S)-(4-hydroxy-3-methoxyphenyl)-2-(S)-(hydroxymethyl)-2,3-dihydro-1,4-benzodioxin-6-yl]chroman-4-one) is other interesting member of the flavonoid family. Silibinin has demonstrated potent antiproliferative effects against various malignant cell lines and also it has low water solubility. Bioavailability of these substances is achieved or improved by complexation with organic compounds or by metal coordination. The oxovanadium(IV) cation is a biometal with important biological properties, and several vanadium compounds show potential pharmacological activity mainly as insulin enhancers, and as osteogenic and antitumoral agents. As part of a project devoted to determine the potential antitumoral properties of oxovanadium(IV) complexes with flavonoids, we have investigated the cytotoxicity and genotoxicity of a new vanadyl(IV) complex with Chrysin and compare its inhibitory effects on tumor cell proliferation with that of the vanadyl(IV) complex of Silibinin. [VO(Chrysin)2EtOH]2 caused a clear inhibitory effect on the proliferation of the human osteosarcoma derived cell line MG-63 (70% vs basal) from 25 µM p