title: Rise in DPA Following SDA-Rich Dietary Echium Oil Less Effective in Affording Anti-Arrhythmic Actions Compared to High DHA Levels Achieved with Fish Oil in Sprague-Dawley Rats.
abstract: Stearidonic acid (SDA; C18:4n-3) has been suggested as an alternative to fish oil (FO) for delivering health benefits of C ≥ 20 long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA). Echium oil (EO) represents a non-genetically-modified source of SDA available commercially. This study compared EO and FO in relation to alterations in plasma and tissue fatty acids, and for their ability to afford protection against ischemia-induced cardiac arrhythmia and ventricular fibrillation (VF). Rats were fed (12 weeks) diets supplemented with either EO or FO at three dose levels (1, 3 and 5% w/w; n = 18 per group). EO failed to influence C22:6n-3 (DHA) but increased C22:5n-3 (DPA) in tissues dose-dependently, especially in heart tissue. Conversely, DHA in hearts of FO rats showed dose-related elevation; 14.8%-24.1% of total fatty acids. Kidney showed resistance for incorporation of LC n-3 PUFA. Overall, FO provided greater cardioprotection than EO. At the highest dose level, FO rats displayed lower (p < 0.05) episodes of VF% (29% vs. 73%) and duration (22.7 ± 12.0 vs. 75.8 ± 17.1 s) than the EO group but at 3% EO was comparable to FO. We conclude that there is no endogenous conversion of SDA to DHA, and that DPA may be associated with limited cardiac benefit.
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation (CSIRO) Food &amp; Nutrition, Kintore Ave, Adelaide SA 5000, Australia. mahinda.abeywardena@csiro.au.
authors.forename: Mahinda Y
authors.initials: MY
authors.lastname: Abeywardena
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation (CSIRO) Food &amp; Nutrition, Kintore Ave, Adelaide SA 5000, Australia. Michael.Adams@csiro.au.
authors.forename: Michael
authors.initials: M
authors.lastname: Adams
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation (CSIRO) Food &amp; Nutrition, Kintore Ave, Adelaide SA 5000, Australia. Julie.Dallimore@csiro.au.
authors.forename: Julie
authors.initials: J
authors.lastname: Dallimore
authors.affiliation: Commonwealth Scientific and Industrial Research Organisation (CSIRO) Food &amp; Nutrition, Kintore Ave, Adelaide SA 5000, Australia. Soressa.Kitessa@csiro.au.
authors.forename: Soressa M
authors.initials: SM
authors.lastname: Kitessa
mesh_terms: D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D004032:Diet; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D036661:Echium / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism / Q000494:pharmacology*; D005395:Fish Oils / Q000378:metabolism / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects; D007511:Ischemia; D007668:Kidney / Q000187:drug effects; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D017207:Rats, Sprague-Dawley; D014693:Ventricular Fibrillation / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*
chemical_list: D000889:Anti-Arrhythmia Agents; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D010938:Plant Oils; D004281:Docosahexaenoic Acids; C062895:stearidonic acid
keywords: Echium oil; cardiac arrhythmia; docosahexaenoic acid; docosapentaenoic acid; eicosapentaenoic acid; fish oil; n-3 fatty acids; rat; stearidonic acid