RESUMO
Doxorubicin (DOX) is a well-known cytotoxic agent used extensively as a chemotherapeutic drug to eradicate a wide variety of human cancers. Reactive oxygen species (ROS)-mediated oxidative stress during DOX treatment can induce cardiac, renal, and hepatic toxicities, which can constrain its use as a potential cytotoxic agent. The present work investigates the antioxidant potential of naringenin (NAR) against DOXinduced toxicities of a Dalton's lymphoma ascites (DLA) tumor-bearing mouse model. Mice were randomized into four groups: a negative control, positive control, DOX (2.5 mg/kg) treated, and DOX (2.5 mg/kg) + NAR (50 mg/kg/d) treated. DOX administration significantly altered the levels of functional markers in blood and antioxidant enzymes in kidney, heart, lung, liver, spleen, and tumor tissues. These changes in antioxidant enzymes and successive lipid peroxidation were prevented by NAR supplementation, resulting in decreases in the risk of toxicity due to DOX therapy. Histopathology results and electron paramagnetic resonance imaging (EPRI) of the tumor microenvironment confirmed this evidence. Using EPRI, pharmacokinetics of the nitroxide, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (3-CP) was monitored intratumorally before and after chemotherapy. EPRI of the DOX + NAR-treated mouse model showed reduced tumor size with significant modification of the hypoxic condition inside the tumor microenvironment. Consequently, these findings suggest that NAR treatment significantly reduces DOX-induced toxicity and the hypoxic condition in a DLA tumor-bearing mouse model.
