Mol. Nutr. Food Res. 2012, 56, 1–8 1 DOI 10.1002/mnfr.201200170 RESEARCH ARTICLE Curcumin attenuates testicular damage, apoptotic germ cell death, and oxidative stress in streptozotocin-induced diabetic rats Mehmet Kanter 1 , Cevat Aktas 2 and Mustafa Erboga 3 1 Department of Histology and Embryology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey 2 Department of Histology and Embryology, Faculty of Medicine, University of Namik Kemal, Tekirdag, Turkey 3 Department of Histology and Embryology, Faculty of Medicine, Trakya University, Edirne, Turkey Scope: The present study was designed to examine the protective and antioxidative effects of curcumin (Cur) on streptozotocin (STZ) induced testicular damage, apoptotic germ cell death, and oxidative stress. Methods and results: Diabetes was induced by a single intraperitoneal injection of STZ (50 mg/kg). The rats in the Cur-treated group were given Cur (100 mg/kg) once a day intragas- trik for 8 weeks starting 3 days prior to STZ injection. Cur treatment significantly decreased the elevated tissue malondialdehyde levels and increased the reduced superoxide dismutase, and glutathione peroxidase enzyme activities in testis tissues samples. The Cur-treated rats in the diabetic group showed an improved histological appearance and serum testosterone levels. Our data indicate a significant reduction in the activity of in situ identification of apoptosis using terminal dUTP nick end-labeling and there was a rise in the expression of proliferating cell nuclear antigen in testis tissues of Cur-treated rats in the diabetic group. Conclusion: These results demonstrate that Cur attenuated testicular damage in diabetic rats by decreasing oxidative stress. Keywords: Apoptozis / Curcumin / Diabetes / Oxidative stress / Testis Received: March 27, 2012 Revised: May 24, 2012 Accepted: May 31, 2012 1 Introduction Diabetes mellitus is one of the oldest disorders known to mankind. It has been presumed that diabetes mellitus results from inherited stresses in modern lifestyle and the rising in- cidence of diabetes is becoming a significant public health problem affecting millions of individuals worldwide. Recent estimates indicate there were 171 million people in the world Correspondence: Professor Mehmet Kanter, Department of His- tology and Embryology, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey E-mail: mkanter65@yahoo.com Fax: +90-216-6022805 Abbreviations: Cur, curcumin; GSH-Px, glutathione peroxidise; H&E, hematoxylin and eosin; MDA, malondialdehyde; MSTD, mean seminiferous tubule diameter; MTBS, mean testicular biopsy score; PCNA, proliferating cell nuclear antigen; ROS, re- active oxygen species; SOD, superoxide dismutase; STZ, strep- tozotocin; TBS, tris buffered saline; TUNEL, terminal dUTP nick end-labeling with diabetes in the year 2000 and this is projected to increase to 366 million by 2030 [1]. Diabetes mellitus has adverse ef- fects on the male sexual and reproductive functions [2]. Serum testosterone impairment and varying degrees of testicular le- sions have also been demonstrated in streptozotocin (STZ) induced diabetic animal models [2, 3]. Enhanced oxidative stress and changes in antioxidant capacity are considered to play an important role in the pathogenesis of chronic diabetes mellitus [4]. Cur, the natural yellow pigment in turmeric, is isolated from the rhizomes of the plant Curcuma longa. It con- stitutes about 3–4% of the composition of turmeric [5]. Protective effects of Cur on cadmium-induced testicular damage [6], ionizing radiation-induced ovairan toxicity [7], metronidazole-induced testicular injury [8], and ischemia- reperfusion-induced testicular damage [9] of laboratory an- imals have been reported. Administration of Cur to diabetic rats also reduced the blood sugar [10]. The purpose of this study was to determine the protective and antioxidative effects of Cur on STZ-induced testicular damage, apoptotic germ cell death, and oxidative stress. C  2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.mnf-journal.com