Effects of saponins, quercetin, eugenol, and cinnamaldehyde on fatty acid biohydrogenation of forage polyunsaturated fatty acids in dual-flow continuous culture fermenters.
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.
Lourenço
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M
Laboratory for Animal Production and Animal Product Quality, Department of Animal Production, Ghent University, Proefhoevestraat 10, 9090 Melle, Belgium.
Cardozo
P W
PW
Calsamiglia
S
S
Fievez
V
V
D000171:Acrolein / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D005054:Eugenol / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000032:analysis; D005260:Female; D005285:Fermentation / Q000187:drug effects*; D006865:Hydrogenation / Q000187:drug effects; D066298:In Vitro Techniques; D008129:Lolium / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology; D012503:Saponins / Q000494:pharmacology
D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005232:Fatty Acids, Volatile; D010936:Plant Extracts; D012503:Saponins; D005054:Eugenol; D000171:Acrolein; D011794:Quercetin; C012843:cinnamaldehyde