RESUMO
Carbon nanomaterials possess antioxidant properties that can be applied in biomedicine and clinics for the development of new highly effective treatments against oxidative stress-induced diseases like ischemic heart disease. We previously reported the usage of graphene oxide (GrO) as a precursor for the elaboration of such prototypes. The promising findings led to the development of two new modifications of GrO: nitrogen-doped (N-GrO) and l-cysteine functionalized (S-GrO) derivatives as possible antioxidant agents in ischemia-reperfusion (I/R) conditions. In this study, the cardioprotective and antioxidant potential of modified GrO as a pre-treatment in rats was evaluated for the first time. In Langendorff isolated rat heart I/R model, the left ventricle developed pressure (LVDP), the end-diastolic pressure (EDP), the maximal (dP/dtmax) and minimal (dP/dtmin) value of the first derivative of LVDP, and heart rate (HR) were measured. The oxidative-nitrosative markers, in particular, the rate of O2*- and H2O2 generation, the content of malonic dialdehyde, diene conjugates, and leukotriene as well as cNOS and iNOS activity were estimated. Obtained results show a significant restoration of cadiodynamic parameters at the reperfusion period. Simultaneously, all samples significantly reduced the rate of reactive oxygen species (ROS) and lipid peroxidation markers in cardiac homogenates and preserved cNOS activity at the preischemic level. This evidence makes GrO derivatives promising candidates for the correction of reperfusion disorders affecting myocardial function.