Cardiotoxicidade induzida pela doxorrubicina: patogenia, diagnóstico e terapias antioxidantes

Abstract

The doxorubicin (DOX) is an antibiotic of anthracyclines family (ANT) which stands out as one of the most important antitumoral used in human and animals. It has limited clinical value due to its cardiotoxicity, which is associated with its serum concentration. The cardiotoxicity of ANT is common in pacients receiving doses above 500 mg/m2 and it is attributed to lipid peroxidation of cardiomyocytes membranes. Among the tests for cardiac monitoring before, during and after chemotherapy with ANT the most used are the imaging and biochemical markers. Radiography is a simple test and the first to be performed. However, it has diagnostic limitation for assessing only the cardiomegaly. Moreover, electrocardiography is very useful to acute cases of cardiotoxicity induced by the DOX in which arrhythmias are common. The echocardiography is the most widely used method because it is minimally invasive and has extensive diagnostic value. Myocardial biopsy is an effective diagnostic method, however invasive, which limits its application. The DOX is one of several exogenous sources of free radicals. In this context, natural substances such as phenols, flavonoids, tocopherols, ascorbic acid, carotenoids, and vitamin E represent chemicals with antioxidant activity and have been investigated with the objective of reducing cardiotoxicity induced by DOX without decrease its chemotherapeutic potential.