Cardioprotective roles of aged garlic extract, grape seed proanthocyanidin, and hazelnut on doxorubicin-induced cardiotoxicity

Doxorubicin (DXR) is a chemotherapeutic agent used effectively in the treatment of several childhood malignancies. During treatment, cardiotoxicity caused by cell damage due to the free oxygen radicals that are generated is a major limiting factor. This study was undertaken to determine whether DXR-induced cardiotoxicity could be prevented by natural foods with antioxidant properties such as aged garlic extract (AGEX), grape seed proanthocyaniclin (PA), and hazelnut. Wistar albino male rats were assigned randomly to 9 groups each consisting of 15 rats. AGEX, PA, and hazelnut groups received these antioxidants in addition to their standard rat diet. They were also treated with cumulative intraperitoneal (i.p.) injections according to 2 different regimens: either a high-dose of 15 mg/kg DXR (3.75 mg/kg per week for 4 weeks) or a low-dose of 7.5 mg/kg DXR (1.875 mg/kg per week for 4 weeks). The control group received i.p. 0.9% saline. AGEX, PA, or hazelnut supplements were given orally to the groups for a 6-week period starting I week before the DXR treatment and ending I week after the treatment. One week after the last DXR injection, heart tissue samples were analyzed to determine malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and xanthine oxidase (XO) levels, and serum samples were taken for creatine kinase (CK). There were no significant changes in MDA levels among the control, DXR-treated groups, or supplemented groups that received additional natural antioxidant foods. SOD enzyme levels were decreased in rats treated with DXR. PA prevented the decrease at low doses of DXR. DXR treatment decreased CAT enzyme levels, but additional PA and hazelnut consumption increased these levels at low cumulative doses. XO enzyme levels were decreased in AGEX and hazelnut groups, but PA prevented the decrease. CK levels were elevated after DXR administration, indicating myocardial injury, but PA significantly reversed this. Although there were no differences histopathologically between AGEX, PA, and hazelnut groups, the protective effects of AGEX and PA were evident in electron microscopy. In conclusion, the positive effects of natural antioxidant foods on the prevention of DXR-induced cardiac injury could not be clearly shown on the basis of antioxidant enzymes. However, the electron microscopic changes clearly demonstrated the protective effects of AGEX and PA. The supplementation of these antioxidant foods over longer periods may show more definitive results. Human studies with different doses are needed to evaluate the effects of these foods on the human heart.