Effects of sitagliptin and L-theanine combination therapy on testicular tissue in rats with experimental diabetes

This study examines the impact of the combination of sitagliptin and L-theanine on the testis tissue of rats with experimental diabetes. Diabetes mellitus, a chronic metabolic illness, significantly reduces quality of life and can cause male infertility by decreasing sperm count, motility, and testosterone levels. Rats were allocated to five separate groups: control, diabetes, L-theanine, sitagliptin, and combination therapy. The measurements encompassed blood glucose levels, body weight, serum insulin levels, and the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The histological examination of testicular tissue was conducted using H&E, PASH, caspase-12, and PCNA staining techniques, in addition to a TUNEL assay to detect apoptosis. Levels of oxidative stress indicators, including glutathione peroxidase (GPX), malondialdehyde (MDA), and catalase, were also evaluated. The results showed that the group of individuals with diabetes had significantly higher levels of blood glucose, apoptotic indices, GPX, catalase, and MDA levels and activities in comparison with the control group. Although both the L-theanine and sitagliptin groups exhibited some improvement, the combination therapy demonstrated the most significant decrease in histopathological damage and apoptotic markers. These results indicate that the combination of sitagliptin and L-theanine may significantly decrease testicular damage caused by diabetes, making it a promising therapeutic strategy.