title: Effects of dietary n-3 or n-6 fatty acids on interleukin-1beta-induced anxiety, stress, and inflammatory responses in rats.
abstract: The present study demonstrated that an omega (n)-3 fatty acid, ethyl-eicosapentaenoic acid (ethyl-EPA), supplemented diet significantly attenuated the stress/anxiety behavior of rats in the "open field" and elevated plus maze, which was induced by subchronic intracerebroventricular administration of proinflammatory cytokine interleukin (IL)-1beta. Ethyl-EPA also reduced the rise in serum corticosterone induced by IL-1. The n-6 fatty acid ethyl-gamma-linolenic acid (ethyl-GLA) had little effect on the IL-1-induced changes in behavior and the corticosterone concentration. Following IL-1beta administration, ethyl-EPA reduced the elevated prostaglandin (PG) E2 secretion and increased the secretion of antiinflammatory cytokine IL-10 from whole blood cells. Ethyl-GLA showed a similar antiinflammatory effect to ethyl-EPA. By contrast, n-6 fatty acid arachidonic acid (AA) had no effect on the behavior, immune, and endocrine changes induced by IL-1. AA alone enhanced the basal inflammatory response, raised serum corticosterone concentrations, and induced anxiety behavior in the elevated plus maze. The reduced growth rates of rats following the administration of IL-1 was attenuated by ethyl-EPA, and to a greater extent by ethyl-EPA plus ethyl-GLA, but not by AA alone or in combination with ethyl-EPA. Thus, ethyl-EPA would appear to antagonise the endocrine, immune, and behavioral effects of subchronic IL-1 administration. Ethyl-GLA only antagonised IL-1-induced inflammatory changes, whereas AA caused an increase in the secretion of corticosterone and PGE2, and induced anxiety-like behavior without enhancing the effects of IL-1.
authors.affiliation: Department of Psychiatry, University of British Columbia, Canada. caisong@interchange.ubc.ca
authors.forename: Cai
authors.initials: C
authors.lastname: Song
authors.forename: Xuwen
authors.initials: X
authors.lastname: Li
authors.forename: Brian E
authors.initials: BE
authors.lastname: Leonard
authors.forename: David F
authors.initials: DF
authors.lastname: Horrobin
mesh_terms: D000818:Animals; D001007:Anxiety / Q000139:chemically induced*; D016718:Arachidonic Acid / Q000378:metabolism; D003345:Corticosterone / Q000378:metabolism; D004032:Diet; D015232:Dinoprostone / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced*; D007375:Interleukin-1 / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology; D016753:Interleukin-10 / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013268:Stimulation, Chemical; D013312:Stress, Physiological / Q000139:chemically induced*; D017965:gamma-Linolenic Acid / Q000378:metabolism
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D007375:Interleukin-1; D010743:Phospholipids; D016753:Interleukin-10; D016718:Arachidonic Acid; D017965:gamma-Linolenic Acid; D015118:Eicosapentaenoic Acid; D015232:Dinoprostone; D003345:Corticosterone