Effects of gammalinolenic acid on interleukin-1 beta and tumor necrosis factor-alpha secretion by stimulated human peripheral blood monocytes: Studies in vitro and in vivo

Background: Oils enriched in gammalinolenic acid, an unsaturated fatty acid , reduce joint pain and swelling in patients with rheumatoid arthritis. The cytokines interleukin-l beta and tumor necrosis factor-alpha appear to con tribute directly to joint tissue damage in patients with rheumatoid arthrit is. Agents designed to interfere with the actions of interleukin-l beta and tumor necrosis factor-alpha are being used to treat rheumatoid arthritis. Methods: We examined the influence of gammalinolenic acid added to cells in vitro and administered orally in vivo on interleukin-1 beta and tumor necr osis factor-alpha secretion from activated human peripheral blood monocytes . secretion of both cytokines was reduced by gammalinolenic acid. Administr ation of safflower oil as a polyunsaturated fatty acid control devoid of ga mmalinolenic acid did not change secretion of either cytokine, Conclusion: Suppression of IL-beta and TNF-alpha secretion by activated cel ls may be one mechanism whereby gammalinolenic acid suppresses synovitis pa tients with rheumatoid arthritis.