ABSTRACT

Background:
Liraglutide is an incretin mimetic agent that approved recently in type-2 diabetes. The use of vitamin D is associated with an improvement in diabetic neuropathy.
The aim of the study:
Evaluation of the effect of liraglutide and vitamin D each alone and in combination with each other on diabetic neuropathy induced by streptozotocin in rats.
Materials and Methods:
Five groups ofWistar rats were used in the experiment. Diabetic neuropathy was induced in groups 2, 3, 4, and 5 using a single intraperitoneal(i.p.) injection of streptozotocin(STZ) in a dose of 60 mg/kg. The third, fourth, and fifth groups were treated for 4 weeks with liraglutide (0.8 mg/kg), vitamin D3 (12 µg/kg), and combination of the 2 drugs, respectively. Then the behavioral tests were done (hot plate, tail-flick, paw withdrawal pressure, and the rotarod tests). Blood samples were used for assessment of blood glucose, tumor necrosis factor -α (TNF-α) and interleukin-Iβ(IL-Iβ). Malondialdehyde(MDA) and glutathione (GSH)were measured in the sciatic nerve homogenate.
Results:
Liraglutide caused significant improvement in the behavioral tests of the diabetic rats with a significant reduction in blood glucose, TNF-α, IL-1β, and malondialdehyde. Vitamin D caused mild improvement in the behavioral tests, inflammatory and oxidative stress markers. The combined use of liraglutide with vitamin D caused more improvement in diabetic neuropathy tests, inflammatory and oxidative stress markers.
Conclusion:
Liraglutide has a moderate neuroprotective, anti-inflammatory, and antioxidant effects in cases of streptozotocin-induced diabetic neuropathy which are enhanced by the addition of vitamin D.