Materials and Methods: In this experimental study, 64 diabetic rats induced by a single intraperitoneal (IP) injection of STZ (50 mg/kg) were assigned to the following groups (n=8/each): healthy control group, diabetic control group, diabetic group treated daily with crocin at a dose of 50 mg/kg, and one healthy group receiving daily crocin at a dose of 50 mg/kg for 56 days. Some groups such as the controls and diabetics exercised with treadmill, as well as the healthy and diabetic groups performed daily exercise with treadmill and crocin. After crocin treatment, all rats were anesthetized, their blood samples were taken, and the serum level of insulin, glucose, and oxidative stress markers were measured. Finally, the testicles and epididymis were removed and sperm parameters were assessed.

Results: Treatment of diabetic rats with crocin along with treadmill exercise significantly replaced the testicular tissue damage, sperm parameters, glucose, and insulin plasma levels (P = 0.001). In diabetic rats, moreover, the level of malondialdehyde (MDA) was increased and the levels of superoxide dismutase (SOD) and catalase (CAT) enzymes activity were reduced in the testicular tissue (P = 0.001). Crocin administration (50 mg/kg BW) and exercise significantly improved these parameters (P < 0.05).

Conclusions: Our results confirm the antioxidant role of crocin and the positive role of treadmill exercise in improving the sperm parameters and testicular oxidative damage caused by diabetes.