Thymus caramanicus jalas extract reduces serum blood glucose, ameliorates thermal hyperalgesia and motor deficit induced by diabetes in rats

Introduction: Uncontrolled diabetes mellitus could lead to neuropathy in central and peripheral nerve tissues and one of its main signs can be hyperalgesia and motor coordination defect. Due to the blood glucose lowering effect of Thymus species and the presence of polyphenolic compounds with high antioxidant capacity, in this study the effect of Thymus caramanicus jalas extract was investigated on animal model of diabetes-induced neuropathy. Methods: In the present study development of hyperalgesia was examined by tail-flick and rota-rod tests, in streptozotocin-induced diabetic male wistar rats (subcutaneous injection). Animals were given Thymus caramanicus jalas extract (50, 100, 150 and 200 mg/kg) for 6 weeks. The levels of blood glucose were measured at the beginning and the end of the experimental period. Results: Blood glucose levels in diabetic animals which received Thymus extract at the doses of 150 and 100 mg/kg was reduced as compared to the pretreatment levels (p<0.05 and p<0.01, respectively). Untreated diabetic rats showed lower threshold in pain sensation and motor deficit compared with the control animals. However, tail-flick latency and ability to stay on rota-rod were significantly decreased in diabetic animals that received 100 mg/kg (p<0.01) and 150 mg/kg (p<0.001) of extract. Conclusion: The data show that Thymus caramanicus jalas extract has ability to reduce serum glucose levels and attenuate hyperalgesia and motor deficit induced by diabetes in rats. The mechanisms of this effect may be related to (at least in part) the attenuation of blood glucose and prevention of neural damage.