Histopathological examination of rat heart tissues by hematoxylin and eosin: a. control rats and b. CSO-administrated rat showed normal histological and orientation of the cardiac muscle fibers (MFs) with their centrally located nuclei (arrow). c. DOX-treated rats showed showing diffuse vacuolar degeneration of the cardiac muscle fibers, most of which showing signet ring appearance (arrow) and necrosis (dashed arrow), d. Dox-treated rats showing intermuscular edema (Ed), mild inflammatory cells infiltration (dashed arrow) e. CSO/DOX-treated rat showing good restoration of the cardiac muscle fibers with only mild vacuolar degeneration (arrow) and very few necrotic fibers