Original ArticleCardioprotective Effect of Phenytoin on Doxorubicin-induced Cardiac Toxicity in a Rat ModelRazmaraii, Nasser DVM; Babaei, Hossein PharmD, PhD; Mohajjel Nayebi, Alireza PharmD, PhD; Asadnasab, Gholamreza DVM, PhD; Ashrafi Helan, Javad DVM, PhD; Azarmi, Yadollah PharmD, PhDAuthor Information *Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; †Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; ‡School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; §Department of Clinical Sciences, Tabriz Branch, Islamic Azad University, Tabriz, Iran; and ¶School of Veterinary, Tabriz University, Tabriz, Iran. Reprints: Hossein Babaei, PharmD, PhD, Drug Applied Research Center, Research and Development Complex, Tabriz University of Medical Sciences, Daneshgah St, Tabriz 5165665811, Iran (e-mail: [email protected]). The authors report no conflicts of interest. Received June 01, 2015 Accepted October 19, 2015 Journal of Cardiovascular Pharmacology: March 2016 - Volume 67 - Issue 3 - p 237-245 doi: 10.1097/FJC.0000000000000339 Buy Metrics Abstract Doxorubicin (DOX) is an effective anticancer agent, but adverse cardiotoxic effects limit its use. Compounds reducing DOX cardiotoxicity could improve its therapeutic index. This study investigated the protective effects of phenytoin (Phen) for DOX-induced cardiomyopathy. Male Wistar rats were randomized into 5 groups to receive either saline, DOX (2 mg/kg per 48 hours, 6 doses, intraperitoneally) or DOX + Phen (5, 10, or 20 mg/kg/d, starting 4 days before DOX, intraperitoneally). The animals were assessed 24 hours after the last injection. Left ventricular (LV) function and hemodynamic parameters were assessed using transthoracic echocardiography, electrocardiography, and a Millar pressure catheter. Histopathological studies were performed, and the effect of Phen on the cytotoxicity of DOX was evaluated in vitro for the human breast adenocarcinoma cell line. DOX-impaired LV function significantly decreased the LV systolic and diastolic pressures, rate of rise/decrease of LV pressure, ejection fraction, fractional shortening, and contractility index. DOX caused structural changes in myocardial cells. Treatment with Phen decreased DOX-induced toxicity, significantly improved ventricular function, and ameliorated structural changes in the myocardium. Phen also did not interfere with the antitumor effect of DOX. The results confirm the cardioprotective effect of Phen against DOX-induced cardiomyopathy without removing antitumor effect of DOX. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.