Cytotoxicity, genotoxicity and mutagenicity of mixed ternary mononuclear Mg complex based on valproic acid with 1,10-phenanthroline in Saccharomyces cerevisiae and V79 cells.

Valproic acid (VA) is a widely used drug for the treatment of diseases affecting the central nervous system. Due to its epigenetic modulatory potential, it has been studied for possible therapeutic application in anticancer therapies. However, the VA exhibits different side effects in its application. Thus, synthetic coordination complexes with valproate can generate promising candidates for new active drugs with reduced toxicity. In this sense, we investigated the genotoxic and mutagenic potential of the sodium valproate and of the mixed ternary mononuclear Mg complex based on VA with 1,10-phenanthroline (Phen) ligand - [Mg (Valp)₂Phen], in Saccharomyces cerevisiae and V79 cells. The MTT and clonal survival assays in V79 cells indicated that the Mg complex has higher cytotoxicity than sodium valproate. A similar cytotoxicity profile is observed in yeast. This fact is possibly due to the intercalation capacity of [Mg(Valp)₂Phen], inducing DNA strand breaks, as observed in the comet assay and micronucleus test. In this sense, members of the NER, HR, NHEJ and TLS repair pathways are required for the repair of DNA lesions induced by [Mg(Valp)₂Phen]. Interestingly, BER proteins apparently increase the cytotoxic potential of the drug. Furthermore, the [Mg(Valp)₂Phen] showed higher cytotoxicity in V79 cells and yeast when compared to sodium valproate indicating applicability as a cytotoxic agent.