Potential effects of flavonoids from the vegetable component of the diet on the synthesis of estrogens in the rainbow trout Oncorhynchus mykiss: an in vitro study
Pelissero, C.; Lenczowski, M.; De Mones del Pujol, A.; Sumpter, J.P.; Fostier, A. (1993). Potential effects of flavonoids from the vegetable component of the diet on the synthesis of estrogens in the rainbow trout Oncorhynchus mykiss: an in vitro study, in: Barnabé, G. et al. (Ed.) Production, environment and quality: Proceedings of the International Conference Bordeaux Aquaculture '92, Bordeaux, France, March 25-27, 1992. EAS Special Publication, 18: pp. 177-184
In: Barnabé, G.; Kestemont, P. (Ed.) (1993). Production, environment and quality: Proceedings of the International Conference Bordeaux Aquaculture '92, Bordeaux, France, March 25-27, 1992. Special Publication European Aquaculture Society, 18. European Aquaculture Society: Gent. 587 pp., more
In: Special Publication European Aquaculture Society. European Aquaculture Society: Bredene. ISSN 0774-0689, more
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Document type: Conference paper
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| Authors | | Top |
- Pelissero, C.
- Lenczowski, M.
- De Mones del Pujol, A.
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- Sumpter, J.P.
- Fostier, A.
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| Abstract |
In sturgeon, diet has been shown to have an effect on vitellogenin secretion and on plasma levels of sex steroid hormones. These effects have been suggested to be due to the presence of both steroid and flavonoid compounds in the diets. The steroids come from the fish meals and the flavonoid compounds come from the soya extracts which are used as a complementary protein source in most of the fish diets. Within the flavonoid family, some compounds, the so-called isoflavones, are estrogenic and are also designated under the generic name of phytoestrogens. These phytoestrogens have been demonstrated to induce the synthesis of vitellogenin (VTG) in vivo in the Siberian sturgeon and in vitro in the rainbow trout. Other related plant compounds, the flavones, have no known estrogenic activity but have been demonstrated to have an inhibitory effect on human placental aromatase. Because flavones and isoflavones (phytoestrogens) can have actions usually associated with steroid hormones, we decided to test the activity of both flavones and isoflavones on the rainbow trout ovarian aromatase actvity in vitro. Aromatase is the key enzyme in the synthesis of estrogens from androgens, and hence any effect on this enzyme could affect synthesis of estrogens. The results obtained show that most of the compounds tested inhibit the aromatase activity in a dose-response manner. These results are in agreement with a potential effect of the diet on estrogen synthesis in cultured fish. They suggest that flavonoids in the diet may affect the hormonal control of reproduction, and thus could have, as occurs in some mammalian species, undesirable consequences. |
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