Antinociceptive effects of gamma-linolenic acid in the formalin test in the rats

Abstract

Background: Gamma-linolenic acid (GLA) is found in animals and plants that play a role in brain function and metabolism. Objective: This study aimed to investigate the analgesic effects of GLA on peripheral formalin injection. Methods: Wistar rats were randomly assigned to four groups: Sham, formalin, formalin/GLA 100 mg/kg, and formalin/GLA 150 mg/kg. The Formalin test was utilized to create a pain model. A tissue sample was prepared from the spinal cords of rats to measure oxidative stress parameters and pro-inflammatory cytokines. Furthermore, we analyzed the expression of c-Fos protein in the spinal cords. Results: Our findings demonstrate that GLA has a reliable pain-relieving effect in the formalin test. GLA 100 increased SOD (P<0.05), GSH (P<0.001), and CAT (P<0.05), and decreased the levels of c-fos (P<0.001), IL-1β (P<0.001), TNF-α (P<0.001), and MDA (P<0.001) in the spinal cord. Also GLA 150 increased SOD (P<0.05), GSH (P<0.001), and CAT (P<0.05), and decreased the levels of c-fos (P<0.001), IL-1β (P<0.001), TNF-α (P<0.001), and MDA (P<0.001) in the spinal cord. Conclusion: The findings have validated the antinociceptive impact of GLA and hinted towards its immunomodulatory influence in the formalin test.