Neuroprotective Effect of Nypa fruticans Wurmb by Suppressing TRPV1 Following Sciatic Nerve Crush Injury in a Rat

Peripheral nerve injury can result in severe functional impairment and decreased quality of life due to loss of sensory and motor function. Nypa fruticans wurmb (NF) has been used in diverse folk remedies in East Asia. We have previously shown that Nypa fruticans wurmb extract has antinociceptive and anti-inflammatory effects by suppressing TRPV1 in the sciatic nerve injury. The present study investigated the effects of NF on the control of TRPV1 in relation to neuroprotective effects of a sciatic nerve crush injury. To evaluate the neuroprotective effects, an animal behavior test and a physiological function test were performed. Functional recovery and nerve recovery were improved in the NF and NF + SB (SB366791; TRPV1 antagonist) treated group. In the histomorphology evaluation, the neuronal regenerative effect of NF on the injured sciatic nerve was confirmed via hematoxylin and eosin (H&E) staining. In this study, the NF and NF + SB treated group showed neuroprotective and functional recovery effects from the sciatic nerve crush injury. Furthermore, the expression of NF-kappa B and iNOS showed a significantly suppressive effect on NF (p < 0.01), SB (p < 0.01), and NF + SB (p < 0.01) treated group at the 7th and 14th day compared to the vehicle group. This study confirmed the neuroprotective effects of NF on suppressing TRPV1 in a sciatic nerve crush injury. The findings of this study establish the effect of NF as a neurotherapeutic agent to protect the peripheral nerve after a sciatic nerve crush injury.