2002 Fiscal Year Final Research Report Summary
Mechanisms of Reproductive Toxicity by Endocrine Disrupting Chemicals
| Project/Area Number |
11307007
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Public health/Health science
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| Research Institution | Kansai Medical University |
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Principal Investigator |
TOKUNAGA Rikio Kansai Medical University Faculty of Medicine Professor, 医学部, 教授 (40121959)
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| Co-Investigator(Kenkyū-buntansha) |
ENDO Yoko (ICHIKAWA Yoko) Kansai Medical University Faculty of Medicine Assistant Professor, 医学部, 講師 (50193438)
KOHNO Hirao Kansai Medical University Faculty of Medicine Assistant Professor, 医学部, 講師 (30148522)
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| Project Period (FY) |
1999 – 2002
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| Keywords | Endocrine Disrupting Chemicals / Reproductive Toxicity / Estrogen |
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| Research Abstract |
To evaluate the effects of endocrine disrupting chemicals on reproductive functions in human beings, we focused on phytoestrogens that are taken up through food intake. We tested the estrogenic and antiestrogenic effects of two phytoestrotens, resveratrol and naringenin. Resveratrol is reported to act as a "super agonist" in human MCF-7 cells, which was confirmed in the present study. However, in HeLa cells or COS-7 cells, the maximal activation by resveratrol was lower than that by estradiol. In yeast, the resveratrol concentration required for the maximal activation was 50-fold higher than in MCF-7 cells, while there was no difference in optimal estradiol concentrations. Difference in optimal concentration for the maximal activation was observed also observed for naringenin. Whether resveratrol acts as an antagonist was investigated. No antagonistic activity was detected with resveratrol in all reporter assay systems we used. Resveratrol and estradiol exhibited an additive effect in COS-7 or yeast cells, whereas synergistic effect was observed in 293 cells. In contrast to the complex interactions between resveratrol and estradiol, naringenin and estradiol exhibited additive effect in all reporter assay systems we used including yeast. Our study indicates that estrogenic and antiestrogenic activity of structurally diverse phytoestrogens is complex and unpredictable. To screen the estrogenic ingredients, possibly found in beverages, we prepared the extracts from beer hops and herb tea mixtures and determined their estrogenic activities. Two hops and four herb tea mixtures gave positive results. The common ingredients contained only in those herb tea mixtures was liquorice root.
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