Background. Silver nanoparticles (AgNPs) are more often used in various products, and consequently the potential deleterious effects associated with exposure to them are of concern. Several lines of evidence have demonstrated that the toxicity of AgNPs affects different organs and leads to some side effects, including weight loss, inflammation and cell death. Objectives. The aim of this study was to evaluate the effect of different concentrations of AgNPs on sperm parameters and testicular histology. Material and methods. In the present study, 28 male adult Wistar rats were categorized into a control group and 3 experimental groups (AgNP-1, AgNP-2 and AgNP-3), intraperitoneally (i.p.) receiving 30, 125 and 300 mg/kg of AgNPs, respectively. Twenty-eight days after injection the epididymes and the testes of each rat were dissected in order to evaluate sperm parameters, sperm chromatin integrity and histomorphometric changes in the testicular tissue. Results. The results showed a significant decrease in sperm count (p < 0.0001), vitality (p < 0.05) and morphology changes (p < 0.001) in the group receiving 300 mg/kg of AgNPs compared to the control group. A significant decrease was also observed in the number of spermatogonia, Sertoli and Leydig cells in the AgNP-2 and AgNP-3 groups (p < 0.05). The evaluation of sperm chromatin did not show any significant differences among the experimental groups (p > 0.05). Conclusions. The data showed some dose-dependent adverse effects of AgNPs on sperm and seminiferous tubules. More experimental investigations are necessary to draw better conclusions regarding the safety of nanoparticles (NPs) on the male reproduction system.

Reproductive dysfunction is one of the diabetes complications. Resveratrol, a polyphenol 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 streptozotocin 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. K E Y W O R D Santioxidants, chromatin, diabetes mellitus, hyperglycaemia, male reproductive system, resveratrol, spermatozoon How to cite this article: Bahmanzadeh M, Goodarzi MT, Rezaei Farimani A, Fathi N, Alizadeh Z. Resveratrol supplementation improves DNA integrity and sperm parameters in streptozotocin-nicotinamide-induced type 2 diabetic rats.

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