Protective effects of oleuropein on structural changes in the experimental diabetic rat testes

Diabetes mellitus (DM) is a chronic metabolic disease characterized by microvascular and macrovascular complications. In diabetic men, apoptosis increases in testicular germ cells and testicular dysfunction occurs, due to increased oxidative stress. The olive, Which is a plant growing in Mediterranean, includes OLE in its leaves Which recently revealed to effect as an antioxidative. In this study, protective effects of OLE on changes of the rat testicular tissue in streptozotocin (STZ) induced experimental model of diabetes were investigated. Twenty-eight Wistar albino male rats, aged 8-10 weeks were used. The experimental animals were divided into 4 groups that have 7 animals in each group. No application made to the control group. 50 mg/kg single-dose STZ was intraperitoneally (i.p) induced to DM and DM+OLE groups by dissolving on the 0,1 M phosphate-citrate buffer (pH: 4,5). After DM occured, the diabetic group did not receive any medication. OLE (10mg/kg/day) was given to DM + OLE group and only OLE (10mg/kg/day) was given to OLE group, orally for 6 weeks. Rats were decapitated at the end of the experiment and testicular tissues were removed. The testicular tissues were stained with Hematoxylin-Eosin, PAS and TUNEL. The remaining testicular tissue specimens were used for spermatologic examination. 4 When the DM group compared to the control group, it has caused considerable decreases in the sperm number, sperm molitities, body weight, the absolut testis, the epididymis with on the right side and the vesicula seminalis , the prostat weights. When DM+OLE group is compared to the DM groupthere were unimportant increases of the body weights, testes, epididymis and rigth kauda epididymis. Decreaseing of motility and count of epididymal sperm were not healed by OLE treatment in the DM+OLE group. Reproductive parameter OLE group were similiar to the control group. In histological examinations of diabetic group, there were atrophy of tubules, peritubular congestion, and thickening of the basement membrane. But in DM + OLE group, there were similar histological findings with control group. Diabetic group had a increase in apoptotic cell with TUNEL staining. There was a reduction in apoptotic cells in DM + OLE group compared to diabetic group. In the group only OLE administrated rat; interstitial tissue and seminiferous tubules had degeneration. As a result, determination of the protective effects of OLE against the testicular damage caused by DM, new treatment approaches may provide in order to prevent complications of diabetes. Key words: Diabetes mellitus, testes, oleuropein