Neuroprotective effect of genistein in peripheral nerve injury

Abstract

Aim: To investigate the effects of genistein in a rat model of sciatic nerve crush injury and complete sciatic nerve transection. The effects of genistein were compared with those of gabapentin, which is widely used in clinical practice for peripheral nerve injury. Material and Methods: Forty-eight rats were randomly divided into six groups (8 rats in each group): group 1 (sham); group 2, sciatic nerve crush injury (control); group 3, sciatic nerve crush injury+genistein 20 mg/kg; group 4, sciatic nerve crush injury+gabapentin 90 mg/kg; group 5, sciatic nerve transection+genistein 20 mg/kg; group 6, sciatic nerve transection+gabapentin 90 mg/kg. The effects of genistein and gabapentin were assessed with immunohistochemical staining for growth associated protein-43 (GAP-43) and myelin basic protein (MBP). Interleukin-1β and tumor necrosis factor a levels in the injured nerve specimens were assessed as a measure of inflammatory response; walking track analysis and sciatic function index for neurological recovery and the paw mechanical withdrawal threshold were examined for neuropathic pain. Results: On histopathological examination, genistein use was associated with a greater immunoreactivity for GAP-43 and MBP compared with that associated with gabapentin. Genistein and gabapentin had similar effects on anti-inflammatory activity, functional recovery, and neuropathic pain. ConclusIon: Genistein and gabapentin exhibit positive effects on histopathology, inflammation, and clinical findings of peripheral nerve injury. When the systemic side effects of gabapentin are considered, genistein (a basic soy isoflavone that has no side effects) can be used as an alternative to medical treatment in peripheral nerve injury.