Effects of saponins, quercetin, eugenol, and cinnamaldehyde on fatty acid biohydrogenation of forage polyunsaturated fatty acids in dual-flow continuous culture fermenters

• Published in: Journal of animal science 2008-11, Vol.86 (11), p.3045-3053
• Main Authors: Lourenço, M, Cardozo, P.W, Calsamiglia, S, Fievez, V
• Format: Article
• Language: English
• Subjects: Acrolein - analogs & derivatives; Acrolein - pharmacology; aldehydes; Animal productions; Animals; biohydrogenation; Biological and medical sciences; Cattle - metabolism; cinnamaldehyde; continuous systems; dual-flow continuous culture fermenters; eugenol; Eugenol - pharmacology; fatty acid composition; Fatty Acids - analysis; Fatty Acids, Unsaturated - analysis; Fatty Acids, Unsaturated - metabolism; Fatty Acids, Volatile - analysis; Feed and pet food industries; Female; Fermentation - drug effects; Food industries; forage; Fundamental and applied biological sciences. Psychology; Hydrogenation - drug effects; In Vitro Techniques; Lolium - metabolism; monensin; plant extracts; Plant Extracts - pharmacology; polyunsaturated fatty acids; quercetin; Quercetin - pharmacology; saponins; Saponins - pharmacology; Terrestrial animal productions; triterpenoid saponins; Vertebrates
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2007-0708

Four different plant secondary metabolites were screened for their effect on rumen biohydrogenation of forage long-chain fatty acids, using dual-flow continuous culture fermenters. Treatments were as follows: control (no additive), positive control (12 mg/L of monensin), and plant extracts (500 and 1,000 mg/L of triterpene saponin; 250 and 500 mg/L of quercetin; 250 mg/L of eugenol; 500 mg/L of cinnamaldehyde). Monensin increased propionate, decreased acetate and butyrate proportions, and inhibited the complete biohydrogenation of fatty acids resulting in the accumulation of intermediates of the biohydrogenation process (C18:2 trans-11, cis-15 rather than C18:1 trans-11). Cinnamaldehyde decreased total VFA concentration and proportions of odd and branched-chain fatty acids in total fat effluent. Apparent biohydrogenation of C18:2n-6 and C18:3n-3 was also less, and a shift from the major known biohydrogenation pathway to a secondary pathway of C18:2n-6 was observed, as evidenced by an accumulation of C18:1 trans-10 and trans-10, cis-12 CLA. Quercetin (500 mg/L) increased total VFA concentration, but no shifts in the pathways or extent of biohydrogenation were observed. Eugenol resulted in the accumulation of C18:1 trans-15 and C18:1 cis-15, end products of an alternative biohydrogenation pathway of C18:3n-3. Triterpene saponins did not affect the fermentation pattern, the biohydrogenation pathways, or the extent of biohydrogenation. At the doses tested in this study, we could only show a direct relation between changes in the rumen fatty acid metabolism and the presence of cinnamaldehyde but not for eugenol, quercetin, or triterpene saponins.