Study of interaction of antimutagenic 1,4-dihydropyridine AV-153-Na with DNA-damaging molecules and its impact on DNA repair activity

Abstract

Background1,4-dihydropyridines (1,4-DHP) possesses important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. It was shown that the antimutagenic 1,4-dihydropyridine AV-153-Na interacts with DNA. The aim of the current study was to test the capability of the compound to scavenge peroxynitrite and hydroxyl radical, to test intracellular distribution of the compound, and to assess the ability of the compound to modify the activity of DNA repair enzymes and to protect the DNA in living cells against peroxynitrite-induced damage.MethodsPeroxynitrite decomposition was assayed by UV spectroscopy, hydroxyl radical scavenging—by EPR spectroscopy. DNA breakage was determined by the “comet method”, activity of DNA repair enzymes—using Glyco-SPOT and ExSy-SPOT assays. Intracellular distribution of the compound was studied by laser confocal scanning fluorescence microscopy. Fluorescence spectroscopy titration and circular dichroism spectroscopy were used to study interactions of the compound with human serum albumin.ResultsSome ability to scavenge hydroxyl radical by AV-153-Na was detected by the EPR method, but it turned out to be incapable of reacting chemically with peroxynitrite. However, AV-153-Na effectively decreased DNA damage produced by peroxynitrite in cultured HeLa cells. The Glyco-SPOT test essentially revealed an inhibition by AV-153-Na of the enzymes involved thymine glycol repair. Results with ExSy-SPOT chip indicate that AV-153-Na significantly stimulates excision/synthesis repair of 8-oxoguanine (8-oxoG), abasic sites (AP sites) and alkylated bases. Laser confocal scanning fluorescence microscopy demonstrated that within the cells AV-153-Na was found mostly in the cytoplasm; however, a stain in nucleolus was also detected. Binding to cytoplasmic structures might occur due to high affinity of the compound to proteins revealed by spectroscopical methods.DiscussionActivation of DNA repair enzymes after binding to DNA appears to be the basis for the antimutagenic effects of AV-153-Na.

Genotoxic and genoprotective effects of 1,4-dihydropyridine derivatives: a brief review

“…In another study (15), we showed that etaftorone, fenoftorone, and cerebrocrast protected plasmid DNA against peroxynitrite-induced damage. At that point, it was believed that cerebrocrast, a lipid-soluble 1,4-DHP derivative with promising antidiabetic and neuroprotective activities but very weak Ca-channel blocking, and its analogue etaftorone act mainly on mitochondria (16)(17)(18), but both compounds turned out to be DNA binders (15).…”

Genome protecting and genotoxic effects produced by derivatives of 1,4-dihydropyridine

“…Other water-soluble 1,4-DHP: carbatonides (disodium-2,6-dimethyl-1,4-dihydropyridine-3,5-bis(carbonyloxyacetate) derivatives), they are carbatone, metcarbatone, etcarbatone and styrylcarbatone, also interact with DNA although with a lower affinity than AV-153 salts, with the binding constant of styrylacarbatone being higher compared to other compounds, and its binding mode potentially different [13]. When a vast group of water-soluble monocyclic derivatives of 1,4-dihydropyridine were tested for affinity to DNA, it turned out that in compounds with carboxylate groups in position-4, the affinity was dependent on substituents in positions 3 and 5 [13,18].…”

Current Trends and Future Perspectives of Antimutagenic Agents

“…Dihydropyridines(1, (Figure 24) possessed antioxidant and antimutagenic activities. The compounds modified the activity of DNA repair enzymes, to protect the DNA in living cells against peroxynitrite-induced damage[57].…”