Effect of Pregabalin and Gabapentin on Nociceptive Behaviors Induced by Spinal Nerve Ligation

Pain is defined as an unpleasant sensory and emotional experience, associated with actual or potential tissue damage. According to its neurobiological mechanism, pain is classified into nociceptive, inflammatory, dysfunctional, and neuropathic. Neuropathic pain (NP) is caused by a lesion or disease of the somatosensory nervous system. Both pregabalin and gabapentin are pharmaceuticals used as validation drugs in experimental models of NP. Pregabalin was shown to produce significant antihyperalgesic and antiallodynic effects. Gabapentin is used as a reference compound for new analgesics and reduces tactile allodynia in rats. The aim of this work is to evaluate pregabalin and gabapentin effects on nociceptive behaviors induced by spinal nerve ligation (SNL). Female Wistar rats of 140 - 160 g were used, divided into five groups: Naive, SHAM, SNL rats treated with saline solution, SNL rats treated with pregabalin 30 mg/kg p.o., SNL rats treated with gabapentin 300 mg/kg p.o. Nociceptive behaviors were determined by the up and down method. In the establishment of SNL-induced allodynic behavior, a reduction in paw withdrawal threshold was observed in the time course, which was present from day 1 and it was maintained for 28 days post-ligation. With the administration of pregabalin and gabapentin, anti-allodynic behavior was observed in the time course and in the areas under the curve (AUC) of the time course of anti-allodynic behavior, significant difference was observed between pregabalin, and gabapentin groups compared to vehicle with a value of p < 0.0001. The results showed pregabalin and gabapentin induce an antinociceptive effect in rats subjected to SNL.