Decreased antigen-induced eicosanoid release in conjugated linoleic acid-fed guinea pigs

Abstract

E. Cook. Decreased antigen-induced eicosanoid release in conjugated linoleic acid-fed guinea pigs. Am J Physiol Regulatory Integrative Comp Physiol 282: R1104-R1112, 2002 10.1152/ ajpregu.00075.2001.-This study investigated the capacity of conjugated linoleic acids (CLA) to reduce ex vivo antigeninduced release of eicosanoids in a type I hypersensitivity model. Guinea pigs were fed a diet containing 0.25% safflower oil (control) or 0.25% CLA [43% trans (t)10, cis (c)12; 41% c9, t11/t9, c11 18:2] for 2 wk before and during sensitization to ovalbumin (OVA). Lungs, tracheas, and bladders were incubated in physiological saline solution (PSS) for 1 h (basal mediator release) and challenged with OVA (0.01 g/l PSS) for 1 h (mediator release in response to antigen). Eicosanoids were quantified by HPLC/tandem mass spectrometry or enzyme immunoassay. CLA feeding resulted in no change in basal release but decreased eicosanoid release from sensitized tissues in response to antigen challenge in the following manner: thromboxane B 2, 6-keto-prostaglandin (PG)F1␣, PGF 2␣, PGD2, PGE2 by 57-75% in lung, 45-65% in trachea, and 38-60% in bladder; and leukotriene C 4/D4/E4 by 87, 90, and 50% in lung, trachea, and bladder, respectively. These data indicate that feeding CLA reduces lipid-derived inflammatory mediators produced by this type I hypersensitivity model. type I hypersensitivity; lung; trachea; bladder A GROUP OF 18-C FATTY ACID isomers referred to as conjugated linoleic acids (CLA) has been shown to have many biological effects, including modulation of the immune system (9, 26, 37, 38). We previously showed that dietary CLA lowered prostaglandin (PG)E 2 and histamine release in response to antigen challenge (42) in a guinea pig model for type I (immediate) hypersensitivity, a standard model for studying asthma and allergies (12, 41). The mechanism by which CLA lower PGE 2 levels may be, at least in part, inhibition of cyclooxygenase (COX), the enzyme responsible for the initial steps in converting arachidonic acid into prostanoids [PG and thromboxanes (TX)] (2). CLA isomers are similar to linoleic acid (the precursor of arachidonic acid), except the double bonds are in a conjugated formation (i.e., a 1,3-diene, not methylene interrupted). This structural difference (a conjugated diene) in similar 20-C fatty acids has been shown to inhibit the enzymatic activity of COX in vitro as measured by PG production (28).For many years, prostanoids have been implicated in the pathogenesis of type I hypersensitivity disorders such as asthma. We hypothesized that feeding dietary CLA would decrease prostanoids and leukotrienes (LT) released in response to antigen challenge. A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was used to quantify the prostanoids released from sensitized guinea pig tissues exposed to antigen in tissue baths. Stable products of each of the five possible pathways downstream of COX were analyzed. LT were quantified using a combination of LC/MS/MS and enzyme immunoassay. Previous investigation...

Effects of cis-9, trans-11 and trans-10, cis-12 conjugated linoleic acid (CLA) isomers on immune function in healthy men

“…However, the data on effects of CLA on PGE 2 production seem inconsistent, as several studies have shown inhibition of PGE 2 production in vitro (Liu & Belury, 1998;Miller et al, 2001) and in CLA-supplemented rats Sugano et al, 1997Sugano et al, , 1998 and guinea pigs (Whigham et al, 2001(Whigham et al, , 2002. Other studies are in line with our current finding as they found no significant reduction of PGE 2 production in humans (Kelley et al, 2001), mice (Hayek et al, 1999) and rats (Turek et al, 1998).…”

10t,12c-conjugated linoleic acid inhibits lipopolysaccharide-induced cyclooxygenase expression in vitro and in vivo

“…CLA has been shown to prevent immune-induced wasting (13)(14)(15), decrease antigen-induced eicosanoid release (17,18), and inhibit carcinogenesis (5-7) and atherosclerosis (8)(9)(10) in several animal models. The multiple functionalities of CLA have been hypothesized to be related to eicosanoid signaling (14).…”

“…Feeding trials were conducted to investigate the effects of 9c,11t-CLA and 10t,12c-CLA isomers on COX-2 protein expression and PGE 2 release in vivo. Mouse lung was selected based on known COX-2 expression and PGE 2 release from this organ after inflammatory stimulation (18,(38)(39)(40). As shown in Fig.…”

“…Dietary CLA was shown to prevent body weight loss induced by lipopolysaccharide (LPS), tumor necrosis factor-␣ (TNF-␣ ), or Sephadex (13)(14)(15) and to inhibit nitric oxide production and TNF-␣ release (16). Recent work has demonstrated that dietary CLA inhibited antigen-induced eicosanoid release in a type I hypersensitivity guinea pig model (17,18). Mixed or purified isomers of CLA have also been demonstrated to inhibit inducible isoforms of cyclooxygenase (COX) mRNA and protein expression in vitro (19)(20)(21).…”

Fatty acid profile of <i>Longissimus dorsi</i> muscle of crossbred pigs fed with addition of conjugated linoleic acid or sunflower oil

“…Conjugated linoleic acid is anti-cancerogenic, prevents fat deposition and arteriosclerosis, stimulates the immune system and has anti-inflammatory properties (Basu et al 2000, MacDonald 2000, McCarty 2000, Kritchevsky 2000, Watkins & Seifert 2000, PanczenkoKresowska & Ziemlański 2001, Pfeuffer 2001, Whigham et al 2002, Bawa 2003, Ip et al 2003. Dietetic value of pork depends on carcass fat content and on fatty acid profile, especially on hypocholesterolemic acids.…”