Nitrogen compounds as protectors of oxidative damage induced in H9c2 myoblasts

We have been investigating the potential of new synthetic compounds in different conditions where oxidative stress is involved, as the first step in the development process of drugs that can improve human health. Reactive oxygen species (ROS) are produced during normal cell metabolism and in response to various stimuli, and also frequently occur during cardiac ischemia/reperfusion situations. In this study we evaluated the protective role of four of these new synthetic compounds (FMA4, FMA7, FMA762 and FMA796), against oxidative damage induced to H9c2 myoblasts, by the pro-oxidant tert-butylhydroperoxide (t-BHP). These compounds, namely FMA762 and FMA796, were able to decrease t-BHP-induced cell death, as evaluated both by sulforhodamine B assay and by counting the number of apoptotic nuclei stained with the DNA dye Hoechst 33342. Triple labelling of H9c2 cells with TMRM, calcein-AM and Hoechst probes showed that two of these compounds (FMA762 and FMA796) prevent the alterations in cellular and mitochondrial morphology induced by t-BHP. Moreover, they reduced the t-BHP-induced increase in the activities of caspases 3 and 9, suggesting their involvement in the regulation of apoptotic mechanisms, probably mediated by an action at the mitochondria level. Although the more precise mechanisms underlying the action of these compounds in the apoptotic pathways are currently under investigation, it can be stated that the compounds’ ROS scavenging ability seems to be involved in their protective effects, as a significant decrease in t-BHP-induced intracellular ROS formation was observed in their presence, namely for FMA762 and FMA796. The role of these compounds against oxidative damage induced in cardiac cells encourages their further development for clinical practice, namely as protectors of ischemia/reperfusion conditions.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/17174/2004