Chronic cold exposure aggravates oxidative stress in reproductive organs of STZ-induced diabetic rats: Protective role of Moringa oleifera

Abstract

Hyperglycemia-induced oxidative stress is known to impair the homeostasis of the antioxidant system leading to organ dysfunction. Besides, diabetics residing in temperate and continental zones are facing additional stressors such as extreme cold temperatures wherein sympathetic tone relatively produces corticosterone which may worsen diabetic complications. However, there are no reports on the impact of cold exposure in this regard. Therefore, an attempt was made to assess the changes that occurred in oxidative stress indices in male reproductive organs of cold-stressed diabetic rats; besides, the antidote effects of Moringa oleifera leaf ethanolic extract (MOLE) was investigated. Laboratory acclimatized (12/12 hours light/dark cycle, 25°C ± 2°C, humidity 50% ± 5%) Wistar rats (3 months old, 200 ± 10 g) were divided into six groups: control (Group-I); diabetic (Group-II Streptozotocin, treated at 45 mg/kg bw); cold-stressed at 15°C (Group-III); and duel-stressed (Group-IV: cold-stressed + diabetic). Group-IV animals were further divided (Groups-V, VI and VII) and were supplemented with MOLE at doses of 100, 250, and 500 mg/kg bw/day, respectively. Postexposure for 60 days, they were sacrificed to excise the testis and epididymis; and assessments were made in tissue homogenates for oxidative stress indices. The results revealed the cumulative adverse effect of diabetes and cold stress by altering the enzymatic and non-enzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase, and reduced glutathione) as well as increase in the level of malonaldehyde. Among the MOLE supplementations, the dose of 500 mg/kg bw/day for 60 days exhibited a hypoglycemic effect and offered protection by alleviating the complications in cold-stressed diabetic rats.