Effects of quercetin on testicular damage experimentally created with gentamicin in rats

In this study, it was aimed to determine the changes caused by gentamicin on the testicle and the role of oxidative stress; to investigate whether there are protective effects of quercetin, which is an antioxidant. In our study, 24 adult male Sprague Dawley rats were divided into 4 groups and the duration of the experiment was determined as 7 days. The control group received intraperitoneal (i.p.) saline daily for 7 days starting from day 1 of the experiment. The second group, gentamicin (GEN), was administered i.p. at a daily dose of 80 mg/kg for 7 days. gentamicin was given. The third group, the quercetin group (QUE), was given 50 mg/kg quercetin i.p. daily for 7 days in the same way. The fourth group, Gentamicin+Quercetin (GEN+QUE), was given 50 mg/kg i.p. daily and 80 mg/kg i.p. gentamicin for 7 days from the first day of the experiment. At the end of the experiment (8th day) the rats under anesthesia (i.p. ketamine 90 mg/kg) were sacrificed by exsanguination. The blood samples taken were placed in a tube with EDTA (ethylene diamine tetra acetic acid) for biochemical parameters. Testis and epididymis tissues were dissected. Sperm count, motility, viability and morphology were analyzed from sperm samples obtained from the epididymis. Histopathological examinations were performed with hematoxylin&eosin (H&E), Masson trichrome and periodic acid Schiff (PAS) staining methods from one half of the testicular tissues obtained. Tissue samples of testis and epididymis were examined histopathologically under light microscope. Johnsen scoring system was used for the evaluation of seminiferous tubule damage in testis and terminal deoxynucleotidyl transferase (TDT)- deoxyuridine triphosphate (dUTP) nick end labeling assay (TUNEL) technique was used for the apoptosis assessment. Biochemically, tissue malondialdehyde (MDA), tissue superoxide dismutase (SOD), tissue catalase (CAT), tissue glutathione peroxidase and plasma MDA levels were measured in the other half of the testicular tissues. As a result of the evaluations, there was a statistically significant decrease in body weight measurements in the QUE and GEN+QUE groups. A statistically significant decrease was observed in the measurement of testicular weights in the gentamicin applied groups compared to the control. In the histopathological evaluations, it was observed that there was an improvement with the addition of QUE in the findings such as decrease in germinal epithelial thickness, decrease in Johnsen score, increase in immature cell shedding tubule rate and increase in the evaluated apoptotic index observed in GEN group testicular tissue. In the sperm analysis, it was observed that sperm count and sperm with abnormal morphology increased in the GEN group compared to the control group, while viability and motility decreased. It was determined that QUE increased sperm morphology and viability in the GEN+QUE group. In biochemical parameters, an increase in MDA levels and a decrease in SOD, CAT and GPx levels were detected in the GEN group. In the GEN+QUE group, it was observed that the MDA level decreased and the SOD, CAT and GPx levels increased compared to the GEN group. Our findings show that gentamicin impairs testicular structure and function, and quercetin treatment can prevent this negative effect. Keywords: Gentamicin, Quercetin, Testis, Apoptosis, Oxidative stress This work was supported by Office of Scientific Research Projects of Karadeniz Technical University. Project number: TTU-2019-8461