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Are dietary genistein and equol potent enhancers of eicosapentaenoic acid and docosahexaenoic acid levels in rainbow trout ( Oncorhynchus mykiss )?
Author(s) -
Fickler Anna,
Torno Claudia,
Staats Stefanie,
Rimbach Gerald,
Schulz Carsten
Publication year - 2019
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.14097
Subject(s) - equol , eicosapentaenoic acid , docosahexaenoic acid , biology , phytoestrogens , genistein , rainbow trout , fish oil , food science , fatty acid , polyunsaturated fatty acid , biochemistry , endocrinology , daidzein , estrogen , fishery , fish <actinopterygii>
Phytoestrogens are putatively able to enhance the biosynthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but have also been shown to affect fish growth dose dependently. The aim of the present study was to identify a concentration for the phytoestrogen genistein and the phytoestrogen metabolite equol that further increases the endogenous biosynthesis of EPA and DHA without impairing fish growth. Juvenile rainbow trout (87.2 ± 0.3 g) were fed seven diets on a fixed ratio for 8 weeks. A vegetable oil‐based diet served as a control diet and was supplemented with equol (EQ) and genistein (G), respectively, at 0.1%, 0.2% and 0.3% of feed dry matter (1, 2 and 3). Growth and nutrient composition of whole body homogenates were not affected by dietary treatments. EPA and DHA levels in liver, fillet and whole body samples were not significantly increased by EQ and G diets. Fish fed EQ diets showed dose dependently increased liver weights and C18:0 liver levels, indicating estrogen‐like effects at increased dietary dosages. In conclusion, the utilization of equol and genistein in plant oil‐based diets in order to enhance the biosynthesis of EPA and DHA seems not reasonable in rainbow trout.