Phytoestrogens: Effects on the Reproductive System:

EVALUATION OF CELL MEMBRANE INTEGRITY OF SPERMATOZOA BY HYPOOSMOTIC SWELLING TEST – “WATER TEST” IN MICE AFTER INTRAPERITONEAL DAIDZEIN ADMINISTRATION

The functional integrity of the cell membrane of the mice sperm after daidzein administration intraperitoneal was assessed by studying the swelling reaction of the sperm when suspended in distilled water. The results obtained in water test indicate that daidzein, one of the phytoestrogens, decreases the number of normal and live sperm (swollen) in the samples obtaining from vas deferens. This effect was statistically significant in the mice after 7 and 14 days of daidzein administration. In mice treated with daidzein the number of dead (unswollen) sperm was increased, especially in animals after 14 days of experiment.

Effects of Kaempferia parviflora extracts on reproductive parameters and spermatic blood flow in male rats

Krachaidum (KD, Kaempferia parviflora Wall. Ex. Baker), a native plant of Southeast Asia, is traditionally used to enhance male sexual function. However, only few scientific data in support of this anecdote have been reported. The present study investigated the effects of feeding three different extracts of KD (alcohol, hexane, and water extracts) for 3-5 weeks on the reproductive organs, the aphrodisiac activity, fertility, sperm motility, and blood flow to the testis of male rats. Sexual performances (mount latency, mount frequency, ejaculatory latency, post-ejaculatory latency) and sperm motility were assessed by a video camera and computer-assisted sperm analysis respectively, while blood flow to the testis was measured by a directional pulsed Doppler flowmeter. The results showed that all extracts of KD had virtually no effect on the reproductive organ weights even after 5 weeks. However, administration of the alcohol extract at a dose of 70 mg/kg body weight (BW)/day for 4 weeks significantly decreased mount and ejaculatory latencies when compared with the control. By contrast, hexane and water extracts had no influence on any sexual behavior parameters. All types of extracts of KD had no effect on fertility or sperm motility. On the other hand, alcohol extract produced a significant increase in blood flow to the testis without affecting the heart rate and mean arterial blood pressure. In a separate study, an acute effect of alcohol extract of KD on blood flow to the testis was investigated. Intravenous injection of KD at doses of 10, 20, and 40 mg/kg BW caused dose-dependent increases in blood flow to the testis. The results indicate that alcohol extract of KD had an aphrodisiac activity probably via a marked increase in blood flow to the testis.

[High intake of phytoestrogens and precocious thelarche: case report with a possible correlation]

Precocious thelarche is the breast development before 8 years of age with two peaks of incidence during the first two years of life and after 6 years of age. A 4.75-year-old girl presented with thelarche associated to an excessive intake of phytoestrogens (phye). Tanner development B2P1-2, hormonal levels and pelvic US were compatible with peripheral precocious puberty. During follow-up, a daily intake of soy-based foods was observed (> 40 mg phye/day). Soy is rich in phytoestrogens, mainly genistein and daidzein. Although phye are less strong than estradiol, its concentration could be from 13,000 to 22,000 times stronger in children fed only by soy-based formulas. Parents were advised and soy intake was reduced to once a week. Progression of pubertal development ceased at B2-3P1. The patient, now 8.66 years old, keeps growing with similar bone and chronological ages. Some questions related to industrial food security, mainly the soy-based food, remain without precise answer. Although it is well known the entity of non-progressive precocious puberty and premature thelarche, pubertal development in this case was strongly related to excessive daily intake of soy and other phye-rich food that could trigger puberty as endocrine disruptor.

The influence of hollyhock extract administration on testicular function in rats

It has been reported, recently that an aqueous extract from hollyhock flowers (Althaea rosea Cav. varietas nigra) induces weak metabolic changes in rat testes. In the present study, the in vivoinfluence of a methanolic extract was investigated on the metabolism and morphology of the rat testis. To this end, histochemical, morphometric and radioimmunological methods were used. The rats drank the extract at a dose of 100 mg/day for 7 weeks. The histochemical activities of glucose-6-phosphate dehydrogenase (G6PDH) and Delta(5)beta-hydroxysteroid dehydrogenase (Delta(5)betaHSD) increased significantly statistically in the Leydig cells of the experimental rats in comparison with controls. There were no significant changes in either the diameter of seminiferous tubules or the height of seminiferous epithelium after hollyhock administration. Further, only a small amount of hyperplasia of the interstitial tissue was observed. The morphological and histoenzymatic changes in the Leydig cells indicate that the methanolic hollyhock extract has a direct but small influence on rat testes. The insignificant changes in testicular testosterone and estradiol content suggest that the extract does not disturb steroidogenesis.

Distribution of Soy-Derived Phytoestrogens in Human Breast Tissue and Biological Fluids

OBJECTIVE

Soy-derived phytoestrogens may exert several health-beneficial effects. Although plasma and urine levels of these compounds after ingestion have been thoroughly investigated, little is known about their tissue distribution, which is particularly important for tissues with high endogenous estrogen and estrogen receptor concentrations. We aimed to investigate the concentrations of genistein, daidzein, and equol in human breast tissue homogenate and to compare these with the corresponding values in serum and urine.

METHODS

A randomized, double-blind, placebo-controlled study was undertaken to evaluate the concentrations of soy-derived phytoestrogens achieved in breast tissue homogenate, serum, and urine after ingestion of either a soy-based food supplement (n = 9) or a placebo tablet (n = 19) for 5 consecutive evenings before aesthetic breast surgery. To account for the heterogeneity of the breast tissue samples, markers for cellularity, epithelial content, blood vessel content, and total fat were determined.

RESULTS

Urine concentrations of genistein, daidzein, and equol were significantly higher in the soy-supplemented subjects than in the subjects ingesting the placebo (P <.05). Only genistein was found to be significantly higher in serum of the soy group than in the placebo group, and no significant differences were found in breast tissue homogenate concentrations of all analytes between the 2 groups.

CONCLUSION

Intake of soy-based food supplements for 5 consecutive days did not result in significantly higher genistein, daidzein, and equol concentrations in breast tissue homogenate when compared with the placebo group. The concentrations were in the low nanomolar range, whereas in the corresponding serum samples, concentrations were a hundred-fold higher.

Exposure to genistein during gestation and lactation demasculinizes the reproductive system in rats

PURPOSE

Exposure to the phytoestrogen genistein (Indofine Chemical Co., Somerville, New Jersey) can disrupt normal male sexual differentiation. To determine if perinatal (that is gestation and lactation) genistein exposure at doses common in human diets alters masculinization we examined the development of the external genitalia, testes, wolffian ducts and sexual behavior in male rats exposed to genistein supplemented diets during early development.

MATERIALS AND METHODS

Female rats were fed a phytoestrogen-free diet supplemented with no genistein (free), a low genistein dose (low) or a high genistein dose (high) throughout gestation and lactation. Anogenital distance of male offspring was measured weekly from postnatal days 2 to 21. At puberty (postnatal day 40 to 45) preputial separation, and testis length and width of male offspring were measured. At age 70 days reproductive organ masses, plasma testosterone concentration, sperm counts and sexual behavior were assessed in male offspring. RESULTS Exposure to genistein resulted in temporary, prepubertal urogenital abnormalities at postnatal days 21 and 40. Males exposed to genistein had smaller anogenital distance and testis size, and delayed preputial separation. Perinatal exposure to genistein also caused long-term dysfunction in reproductive behavior, in which adult males exposed to genistein were less likely to mount, intromit and ejaculate during mating tests. Males exposed to genistein also had lower testosterone concentrations in adulthood.

CONCLUSIONS

Perinatal genistein exposure results in transient and lasting alterations in masculinization of the reproductive system. These results extend our knowledge of the effects of early genistein exposure on male development and may have implications for human health in terms of potential relationships of endocrine disrupters and urogenital abnormalities thought to be increasing in incidence in boys and men.

Fitoestrogênios: posicionamento do Departamento de Endocrinologia Feminina da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM)

Para avaliar a utilidade dos fitoestrogênios (FE) na terapia de reposição hormonal da menopausa (TRHM), o Departamento de Endocrinologia Feminina da SBEM reuniu um grupo de especialistas para fazer uma revisão bibliográfica e selecionar trabalhos nos quais a metodologia adotada demonstrasse rigor científico. Os FE têm ações estrogênicas e antiestrogênicas, predominantemente sobre os receptores de estrogênios (E) beta, com potência estrogênica muito inferior à do estradiol. O conteúdo de FE nas suas fontes vegetais é variável, dependendo da forma de cultivo, safra, armazenamento e industrialização. Também a conversão dos precursores em fitormônios ativos no organismo humano tem grande variabilidade individual. A maior parte das pesquisas com FE é realizada in vitro ou com animais de laboratório, nem sempre podendo ser extrapoladas para humanos. Com relação à síndrome do climatério, alguns estudos sugerem discreta melhora dos fogachos, sem modificação do ressecamento vaginal ou das alterações do humor. No metabolismo lipídico, alimentação rica em soja, mas não isoflavonas isoladamente, promove redução do colesterol total, do LDL-col e dos triglicerídeos, mas não elevam o HDL-col, como os E, e podem causar aumento da lipoproteína (a), que os E contribuem para diminuir. Embora alguns estudos de curta duração sugiram aumento da densidade mineral óssea com uso de isoflavonas, não há demonstração de redução de fraturas. Conclui-se que não há evidências convincentes que justifiquem o uso de FE ou alimentação rica em soja como alternativa para a TRHM.