Andrologia. 2019;00:e13313. wileyonlinelibrary.com/journal/and | 1 of 8 https://doi.org/10.1111/and.13313 © 2019 Blackwell Verlag GmbH 1 | INTRODUCTION Type 2 diabetes mellitus is a kind of metabolic disease that results from defects in insulin secretion, insulin action or both and is charac‐ terised by hyperglycaemia (Association, 2014). Indeed, hyperglycae‐ mia is considered to generate reactive oxygen species through both enzymatic and nonenzymatic pathways that are associated with damage and dysfunction of different organs such as male repro‐ ductive organ (Fakhruddin, Alanazi, & Jackson, 2017). It is believed that spermatozoa are vulnerable to reactive oxygen species damage (Agarwal, Virk, Ong, & Plessis, 2014; Amaral et al., 2013). Metabolism of glucose is an important event in spermatogen‐ esis. Many studies confirmed the detrimental effect of diabetes on semen parameters, chromatin integrity and DNA fragmenta‐ tion in human and other mammals. Most of these changes are oxidative in nature (Bahmanzadeh, Vahidinia, Mehdinejadiani, Shokri, & Alizadeh, 2016; La Vignera, Condorelli, Vicari, D'Agata, & Calogero, 2012; Maiorino, Bellastella, & Esposito, 2014). It is Received: 30 December 2018 | Revised: 7 April 2019 | Accepted: 17 April 2019 DOI: 10.1111/and.13313 ORIGINAL ARTICLE Resveratrol supplementation improves DNA integrity and sperm parameters in streptozotocin–nicotinamide‐induced type 2 diabetic rats Maryam Bahmanzadeh 1,2 | Mohammad Taghi Goodarzi 3 | Azam Rezaei Farimani 4 | Nasibeh Fathi 2 | Zohreh Alizadeh 1,2 1 Endometrium and Endometriosis Research Center, Hamadan University of Medical Sciences, Hamadan, Iran 2 Department of Anatomical sciences, School of medicine, Hamadan University of Medical Sciences, Hamadan, Iran 3 Department of Biochemistry, Shahrood Branch, Islamic Azad University, Shahrood, Iran 4 Department of Basic Medical Sciences, Neyshabur University of Medical Sciences, Neyshabur, Iran Correspondence Zohreh Alizadeh, Department of Anatomical sciences, Hamadan University of Medical Sciences, Shahid Fahmideh Ave P.O.Box. 65178‐518, Hamadan, Iran. Emails: alizadeh@umsha.ac.ir; alizadeh. zohreh@gmail.com Funding information Vice‐chancellor for Research and Technology, Hamadan University of Medical Sciences, Grant/Award Number: 9311145896 Abstract Reproductive dysfunction is one of the diabetes complications. Resveratrol, a poly‐ phenol compound, shows antidiabetic and antioxidant effects. The aim of the present study was to investigate the protective effects of resveratrol on sperm parameters and chromatin quality in experimentally induced type 2 diabetes by streptozotocin and nicotinamide. Forty male adult Wistar rats were grouped into normal control, diabetic control and resveratrol‐treated diabetic groups (1, 5 and 10 mg/kg orally treated for 30 days). Type 2 diabetes was induced using a single dose of streptozo‐ tocin and nicotinamide by intraperitoneal injection. Then, the different parameters and chromatin condensation of the epididymal extracted spermatozoon were studied using aniline blue (AB), acridine orange (AO) and toluidine blue (TB) staining. The sperm parameters including count, motility and viability had significant reduction in diabetic rats ( p < 0.05). Resveratrol increased count, motility and viable spermatozoa relative to the diabetic group ( p < 0.05). The mean percentage of AB, AO and TB staining positive spermatozoa was increased in diabetic groups compared to control ( p < 0.001) and decreased after treatment with 1 and 5 mg/kg resveratrol ( p < 0.001). The results of AO and TB staining showed that resveratrol did not have any beneficial effect on chromatin condensation and denatured DNA at the dose of 10 mg/kg. KEYWORDS antioxidants, chromatin, diabetes mellitus, hyperglycaemia, male reproductive system, resveratrol, spermatozoon