Maslinic acid as a feed additive to stimulate growth and hepatic protein-turnover rates in rainbow trout (Onchorhynchus mykiss).
Maslinic acid is a triterpene present in a considerable proportion in solid residues from olive-oil production. In the present work the effects of maslinic acid on growth, protein-turnover rates and nucleic-acid concentration on liver were investigated in the rainbow trout. Five groups of 120 fish of a mean body mass of 20 g were fed for 225 days with diets containing 0, 1, 5, 25 and 250 mg of maslinic acid per kg diet. At the end of the experiment, whole-body and liver weight and growth rate of trout fed with maslinic acid were higher than controls. The highest weight increase was registered for the group fed 250 mg kg(-1), representing a 29% increase over controls. The total hepatic DNA or liver cell hyperplasia levels in trout fed with 25 and 250 mg of maslinic acid kg(-1) were 37% and 68% higher than controls. Also in these same groups of trout, fractional and absolute hepatic protein-synthesis rates were significantly higher than in control, and significant increments in hepatic protein-synthesis efficiency and protein-synthesis capacity were reported. In close agreement with these results, microscopy studies showed that trout fed on 25 and 250 mg kg(-1) hepatocytes appeared to be more compact, with a larger rough-endoplasmic reticulum and larger glycogen stores than controls. These results suggest that maslinic acid can act as a growth factor when added to trout diet.
Fernández-Navarro
Mónica
M
Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Granada, Granada, Spain.
Peragón
Juan
J
Esteban
Francisco José
FJ
de la Higuera
Manuel
M
Lupiáñez
José Antonio
JA
D000818:Animals; D004247:DNA / Q000378:metabolism; D004032:Diet; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D017686:Oncorhynchus mykiss / Q000254:growth & development* / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D014315:Triterpenes / Q000494:pharmacology*; D009828:Oleanolic Acid / Q000031:analogs & derivatives
D004247:DNA; D011506:Proteins; D012313:RNA; D014315:Triterpenes; C412811:maslinic acid; D009828:Oleanolic Acid