**6. Conclusion**

*Antioxidants*

[2, 5, 6, 28–30, 33, 35].

**to various treatments**

reproductive disorders [43–45].

the beneficial effects of KV against testicular damage induced by various chemicals

**5.4 Assessment of antioxidant enzymes in the testicular and epididymal tissues** 

Antioxidant enzymes such as SOD, CAT, and GPX play a crucial role in protecting the testes and epididymal tissues against OS associated damage and male

diabetic rats when compared to nondiabetic control rats (**Table 1**). This is in agreement with a study by Adaramoye and Lawal [49] who demonstrated that a diabetogenic agent reduced SOD activity in epididymal tissue. Both catalase and GPx activities in the testes and epididymis were significantly lower in STZ-induced diabetic rats than in the nondiabetic control rats. Glutathione peroxidase shares the substrate, H2O2, with CAT; it alone can react effectively with lipids and other organic hydroperoxides, being the major source of protection against low levels of OS. Some authors supported the idea that GPx was essential in the protection against OS under normal conditions [54]. Others believed in a protective role for these enzymes only under OS conditions [2]. Generally, in our study, the activity of testicular and epididymal antioxidant enzymes SOD, CAT, and GPx was depleted in diabetic rats. Diabetes-induced tissue OS is further supported by the elevated levels

Numerous compounds with antioxidant activities have been shown to improve or normalize the activities of antioxidant enzymes in nondiabetic and diabetic rats, respectively [4]. In the present study, the supplementation of KV for 6 weeks to the normal rats did not change SOD, CAT, and GPx activities compared to the nondiabetic rats. This might be due to the interference between natural antioxidants produced by the body and the antioxidant effects of KV. The treatment of STZ-induced diabetic rats with KV influenced the activity of SOD, CAT, and GPx compared to the diabetic groups (**Table 1**). Similarly, to previous studies, the supplementation of dietary antioxidants to experimental animals has shown a positive correlation between natural dietary supplementation and increased antioxidant enzyme levels in induced OS models. In other studies, KV restored antioxidant enzymes in the testes of diabetes-induced rats [5, 49]. The protective effect of KV observed in the testes and epididymis of diabetic rats might either be due to the inhibition of glycation by the antioxidant enzymes or scavenging abilities of ROS, thus decreasing the formation of LPO [5, 27–30]. Insulin has been used in the management of diabetes by restoring pancreatic insulin deficiency. From our results it is clear that synthetic insulin had improved the levels of testicular and epididymal antioxidant enzymes in STZ-induced

diabetic rats. These results confirm the central role of insulin in energy homeostasis and also make it an important signaling factor in the reproductive tract [2, 7]. The observed effects of KV on the testes and epididymis of STZ-induced diabetic rats in the present study could be attributed to its hypoglycemic and antioxidant

Physiological and pathophysiological conditions such as diabetes influence the level of production and activity of these antioxidant enzymes [2, 6]. The reduction in antioxidant enzymes has been previously reported in diabetic animals [20]. The observed reduction in antioxidant enzyme activities could be due to the oxidative inactivation of the enzyme by ROS or by the glycation of the enzymes [20, 45]. The reduced activity of SOD, CAT, and GPX in the epididymal and testicular tissues has been observed following STZ induction of diabetes, and this may result in a number of deleterious effects due to the accumulation of superoxide radicals and H2O2. In epididymal tissue the SOD activity was significantly lower in STZ-induced

**308**

properties.

of MDA.

The findings of this study emphasized the protective effects of KV against diabetes-associated OS in the testicular and epididymal tissues by enhancing antioxidant defense system in STZ-induced diabetic rats. The present study showed that that KV has the potential of being used as a treatment for diabetes-related pathologies and their complications especially testicular dysfunction. We propose further investigations to elucidate the effects of KV on male reproductive organ function in order to advance the current knowledge which could also be extended to clinical research.
