Olive (Olea europaea L.) leaf extract prevents motor deficit in streptozotocin-induced diabetic rats

Olive leaves have been recommended in the scientific literature and traditional medicine as a cure for the treatment of diabetes and this plant has powerful antioxidants and neuroprotective effects. Here, we studied the possible effects of olive leaf extract (OLE) on motor deficits in diabetic neuropathy. The rotarod treadmill test was used to access motor coordination in streptozotocin-induced diabetic rats. Different doses of OLE (100, 300 and 500 mg/kg, i.g.) were given. Serum glucose and insulin levels were assessed by specific kits. Four weeks after diabetes induction, glucose level was significantly decreased and insulin concentration increased (P<0.001). The rotarod treadmill test showed a marked impairment of the motor coordination of the diabetic animals (P<0.001). The retention time of the diabetic animals was reduced by 61.2% compared to the control animals, whereas treatment with 300 mg/kg OLE increased retention time to 83.6% of the control values. That dose had a moderate lowering effect on serum glucose with no effect on insulin levels. The results suggest that olive leaf extract has protective effects against high glucose-induced motor defects in diabetic rats.