Background: Although two novel synthesized compounds with tri-aryl structures; 3-(4-chlorophenyl)-5-(4-fluorophenyl)-4-phenyl-4,5-dihydro-1,2,4-oxadiazole (A) and 3,5-bis-(4-chlorophenyl)-4-phenyl-4,5-dihydro-1,2,4-oxadiazole (B) have been previously demonstrated to possess remarkable anti-breast cancer activity, their cardiotoxicity remains a major concern due to their mechanism of action. To address this concern, we assessed the ability of these compounds to cause toxicity towards H9c2 cardiomyocytes as an in vitro model of cardiotoxicity.
Methods: Cytotoxic activity of both compounds was explored in vitro on H9c2 cells using MTT assay. Annexin V/PI method, intracellular ROS determination and mitochondrial membrane potential assay were applied to elucidate the mechanism of action of the cell death.
Results: MTT assay revealed a concentration- and time-dependent cardiotoxicity. Findings of apoptosis by double staining with annexin V and propidium iodide divulged no cell death including apoptosis and necrosis at the concentration that were effective to inhibit cancer cells proliferation (10 μM) at 24 and 48 h. Furthermore, flow cytometric measurement of membrane potential and ROS determination using DCFH-DA verified the safe concentration of the compounds against H9c2 cells with no cardiotoxic effect. However, the higher concentration of the compounds could induce cell death through ROS-mediated mitochondrial dysfunction.
Conclusions: Altogether, the results represented two novel chemical molecules possessing anti-breast cancer activity with minimum cardiac side effect.
Keywords: Apoptosis; Cardiotoxicity; Mitochondrial potential; ROS.