Effects of the Antioxidant Agent Tempol on Periapical Lesions in Rats with Doxorubicin-induced Cardiomyopathy

Introduction: Cardiovascular diseases have been associated with increased risk of endodontic complications. This study evaluated the effects of the antioxidant agent tempol on periapical lesions in rats with doxorubicin-induced cardiomyopathy in comparison with control animals. Methods: Forty male Wistar rats were divided into 4 groups: (1) naive rats orally treated with saline solution (10 mL/kg, during 21 days after periapical lesion induction); (2) naive rats treated with tempol (30 and 50 mg/kg, during 21 days after periapical lesion induction) by oral pathway; (3) rats with doxorubicin-induced cardiomyopathy treated with saline solution by oral route (10 mL/kg, from day 3 to day 10 after initiating treatment with doxorubicin); and (4) rats with doxorubicin-induced cardiomyopathy orally treated with tempol (30 and 50 mg/kg, from day 3 to day 10 after initiating treatment with doxorubicin). Periapical lesions were induced on the first right mandibular molar tooth. After 21 days of apical periodontitis induction, the animals were killed, and the mandibles were collected for radiographic and histologic analysis. Results: The oral administration of tempol (50 mg/kg) was able to significantly prevent the establishment of periapical lesions in either control animals or rats submitted to the model of doxorubicin-induced cardiomyopathy, according to radiographic and histologic evaluation. Nevertheless, the protective effects of tempol were virtually greater in control animals in comparison with doxorubicin-treated rats, as indicated by histologic inflammatory assessment, which might be related to the increased production of free radicals under cardiomyopathy. Conclusions: We provide novel evidence on the beneficial systemic effects of the antioxidant tempol on apical periodontitis in both control animals and rats with doxorubicin-elicited cardiomyopathy. (J Endod 2012;38:191-195)