D-limonene complexed with hydroxypropyl-β-cyclodextrin prevents impaired cardiac excitation-contraction coupling by reducing oxidative stress and cardiac apoptosis in an animal model of cardiotoxicity induced by doxorubicin

Doxorubicin (Dox) is one of the most used drugs in the treatment of various cancers, but its cardiotoxicity limits its use. The aim of this study was to investigate the cardioprotective effect of the formulation d-limonene-hydroxypropyl-β-cyclodextrin (HβDL) on a murine model of Dox-induced cardiotoxicity. Mice were divided into groups: Control (NaCl 0.9 %), Dox (20 mg/kg), and Dox + HβDL (10 mg/kg). Drugs were administered intraperitoneally once every five days. Heart histological parameters, L-type Ca²⁺ current (I_Ca,L), intracellular and mitochondrial reactive species and mitochondrial mass, calcium transient, sarcomeric shortening, redox status (lipoperoxidation, oxidant, and antioxidant enzymes activity), apoptotic and antiapoptotic proteins expression as well NOX-related proteins were evaluated. HβDL prevented heart histological changes, including cellular infiltrate and vacuoles caused by Dox, and also prevented the increases in calcium waves, I_Ca,L, cytoplasmic and mitochondrial reactive species and mitochondrial mass, expression of Bax, Caspase-3, gp91^phox, NOX4 and p22phox, and lipoperaxidation induced by Dox. Moreover, sarcomeric shortening was reduced in the Dox group, but preserved in HβDL treated animals. Glutathione peroxidase activity, which was reduced in Dox group, was also restored in the HβDL group. Our results show the potential cardioprotective effect of HβDL in Dox-induced cardiotoxicity through improved redox status and excitation-contraction coupling and the suppression of apoptotic pathways in cardiomyocytes.