CO 048: ANTI-HYPERALGESIC EFFECT OF A NEUROPROTECTIVE COMPOUND IN ANIMAL MODELS OF PAIN

J Pharm Pharmacogn Res 2(Suppl. 1): S26, 2014

Special supplement with the abstract book of LATINFARMA 2013

Oral Communication

CO 048: ANTI-HYPERALGESIC EFFECT OF A NEUROPROTECTIVE COMPOUND IN ANIMAL MODELS OF PAIN

Castro M, Garrido-Suárez B, Pardo-Ruiz Z, Alcantara Y, Iglesias L, Merino N, Valdés O, Delgado R.

Center of Research and Drug Development, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600, Plaza de la Revolucion, La Habana, Cuba. E-mail: cidem@infomed.sld.cu
Abstract

Introduction: Chronic pain has been estimated to affect 8% of population. However it doesn´t exist an effective treatment for these pathologic phenomena, for this reason, new pharmacologic strategies have emerged to release chronic pain.

Aim: In the present study we evaluate the antihyperalgesic effect of systemic administration of a novel neuroprotective compound (NP1) in animal models of chronic pain with inflammatory and neuropathic components.

Methods: Nociceptive responding, indicated by licking/biting the affected hindlimb, was quantified during 45 min after formalin injection (5%) and mechanical allodynia was measured with von Frey filaments in chronic constriction injury (CCI). In CCI model was also determined nitric oxide concentration in sciatic nerve and in lumbar spinal cord, and was analysed qualitative changes in the histology of sciatic nerve.

Results: NP1 (10-40 mg/kg, p.o.) was effective in attenuating only the acute phase (phase II) of the formalin licking/biting response, dependending the dosis. Benzodiazepine antagonist flumazenil (10 mg/kg i.p.) partially reversed this effect. Its oral administration during 7 days in CCI model augmented the mechanical response thresholds (g) respect with CCI-vehicle group and increased nitric oxide concentration in spinal cord, but not in sciatic nerve. Histologically, it was found that NP1 has a neuroprotective action against Wallerian degeneration in CCI model, which includes less macrophage infiltration, number of digestion chambers and axonal degradation.

Conclusions: Because of this we can conclude that NP1 shows an antihyperalgesic effect in formalin test it could be related with his actions into GABAA/BDZ receptor, and it also has an antiallodynic and neuroprotective action in CCI model, which could be mediated by L-Arginine-NO-GMPc pathway.