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

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, the authors 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 superoxide dismutase (SOD) ( P <0.05), glutathione (GSH) ( P <0.001), and catalase (CAT) ( P <0.05), and decreased the levels of c-Fos ( P <0.001), interleukin-1 beta (IL-1β) ( P <0.001), tumour necrosis factor-alpha (TNF-α) ( P <0.001), and malondialdehyde (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.