Oleuropein Administration Alleviates Nerve Damage Induced by Sciatic Nerve Constriction Injury in Rats.

Objective: Oleuropein has previously been reported to provide neuroprotection in ischemia/reperfusion injury and to alleviate allodynia in neuropathic pain models. This study aims to assess the therapeutic potential of oleuropein, a polyphenolic compound found in olive trees, on sciatic nerve damage induced by chronic constriction injury (CCI) in male rats by comparing its efficacy with gabapentin, a widely used antiepileptic drug for the treatment of neuropathic pain. Materials and Methods: Adult male Wistar rats were randomly allocated into control, neuropathic pain (NP), NP treated with 15 mg/kg oleuropein, and NP treated with 100 mg/kg gabapentin groups. The neuropathic pain model was induced by CCI via ligation of the sciatic nerve at four different locations, each separated by an interval of 1 mm. Treatments were administered via oral gavage for 14 days. Nociceptive behavior in response to thermal stimuli and the sciatic functional index (SFI) were assessed weekly. Nerve conduction velocity, sciatic nerve histology, and the level of thiobarbituric acid reactive substances were evaluated at the end of treatment. Results: Sciatic CCI led to a reduction in nerve conduction and function, increased oxidative stress, and altered neuronal integrity, accompanied by decreased myelin sheath thickness and myelinated fiber diameter. Oleuropein administration significantly increased nerve conduction velocity, improved SFI values over time, significantly reduced oxidative stress, and enhanced neuronal integrity and myelination, surpassing the effects of gabapentin administration. Conclusion: These findings highlight the therapeutic potential of oleuropein in nerve constriction injury and nerve damage, warranting further investigation into its use for nerve injury treatment.