Efeitos das isoflavonas em altas doses sobre o útero da rata

Ameliorating Effects of Natural Antioxidant Compounds on Female Infertility: a Review

The prevalence of female infertility cases has been increasing at a frightening rate, affecting approximately 48 million women across the world. However, oxidative stress has been recognized as one of the main mediators of female infertility by causing various reproductive pathologies in females such as endometriosis, PCOS, preeclampsia, spontaneous abortion, and unexplained infertility. Nowadays, concerned women prefer dietary supplements with antioxidant properties over synthetic drugs as a natural way to lessen the oxidative stress and enhance their fertility. Therefore, the current review is an attempt to explore the efficacy of various natural antioxidant compounds including vitamins, carotenoids, and plant polyphenols and also of some medicinal plants in improving the fertility status of females. Our summarization of recent findings in the current article would pave the way toward the development of new possible antioxidant therapy to treat infertility in females. Natural antioxidant compounds found in fruits, vegetables, and other dietary sources, alone or in combination with other antioxidants, were found to be effective in ameliorating the oxidative stress-mediated infertility problems in both natural and assisted reproductive settings. Numerous medicinal plants showed promising results in averting the various reproductive disorders associated with female infertility, suggesting a plant-based herbal medicine to treat infertility. Although optimum levels of natural antioxidants have shown favorable results, however, their excessive intake may have adverse health impacts. Therefore, larger well-designed, dose-response studies in humans are further warranted to incorporate natural antioxidant compounds into the clinical management of female infertility.

Effects of estrogen-like plant compounds on the vaginal epithelium pituitary, adrenal glands, and uterus of rats

Plant species with recognized estrogenic activity and widely used by Brazil’s female population to prevent the unpleasant symptoms of menopause were investigated in this work to demonstrate if constituents of taro-inhame (Colocasia esculenta ), cumaru (Dipteryx odorata ), and camapu (Physalis angulata ) have the ability to mimic or interfere with the action of estrogens. Moreover, their potential use as natural sources of estrogen-like substances for hormone replacement therapy was evaluated. (a) In vivo pharmacological assays were conducted to determine the estrogenic effects of D. odorata isoflavone-rich extract, P. angulata physalin-rich extract, and C. esculenta flavonoid glycoside-rich fraction (FG) on endocrine glands and reproductive organs of female rats at three different stages of the life cycle. The protocols consisted of uterotrophic assays and cytological evaluation of vaginal smears to detect mucosa cell alterations correlated with changes in hormone levels in each phase of the estrous cycle of female rats. The results indicated that C. esculenta FG exhibited estrogenic activity in prepubescent, pubescent, and adult ovariectomized female rats, while D. odorata isoflavones only promoted a weight increase in the pituitary gland of prepubescent rats after prolonged treatment and P. angulata physalins induced a weight increment in the adrenal glands of ovariectomized rats. Additionally, C. esculenta exerted a significant effect on the opening of the vaginal canal in prepubescent rats and on vaginal epithelium. Prolonged treatment of ovariectomized rats with FG altered the proportion of different types of vaginal epithelial cells in these animals, suggesting an interference of FG with estrogen levels. Colocasia esculenta FG induced hypertrophy of the uterus and pituitary in ovariectomized rats similar to estradiol. To elucidate the mechanism of action of FG, its effects were compared to those of estradiol and of the selective estrogen receptor modulator raloxifene. The results suggest that the efficacy of C. esculenta FG is mediated by binding to selective estrogen receptors present in each organ and that raloxifene inhibits the mechanism of action of FG in the same way as it inhibits the effects of estradiol. The overall findings indicate that C. esculenta FG mimics the action of estrogens, with reduced harmful effects on specific tissues.

A morphological study of uterine alterations in mice due to exposure to cadmium

We investigated the morphologic and molecular effects of exposure to cadmium (Cd) for 30 and 60 days on the uteri of mice. We assessed uterine morphometric measurements, eosinophilia, mast cell numbers, endometrial apoptosis, proliferation and estrogen receptor alpha (ERα) immunoreactivity. We examined vaginal smears that reflected the hormonal alterations in the female reproductive tract. Because the female reproductive tract exhibits different morphology at each stage of the estrous cycle, we sacrificed all animals at estrus to make appropriate comparisons. Female BALB/c mice were exposed to 200 ppm Cd in their drinking water for either 30 or 60 days. Cd exposure caused significant decreases in endometrial thickness and number of glands in estrus phase uteri. The endometrial eosinophilia in the groups exposed to Cd also decreased compared to controls. Cd exposure increased the number of mast cells. Luminal and glandular epithelia were examined using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and by immunostaining proliferating cell nuclear antigen (PCNA) and estrogen receptor α (ERα). Compared to controls, the apoptotic index increased with time in both Cd exposed groups, while the proliferation index decreased. ERα immunoreactivity was decreased in both Cd exposed groups compared to controls; the decrease was most apparent in the 30 day Cd group. We found that 60 day Cd exposure increased apoptosis in the endometrium, which may affect the receptivity of the uterus for implantation.

Soybean isoflavones attenuate the expression of genes related to endometrial cancer risk

OBJECTIVE

We evaluated whether genistein or estrogen treatment has the same effect when administered immediately or late to rats induced with menopause using ovariectomy.

METHODS

Sixty adult female rats were divided into six treatment groups: GI = vehicle immediately after ovariectomy; GII = vehicle 30 days after ovariectomy; GIII = genistein immediately after ovariectomy; GIV = genistein 30 days after ovariectomy; GV = estrogen immediately after ovariectomy; and GVI = estrogen 30 days after ovariectomy. All animals were treated for 30 consecutive days. At the end of the treatment, part of the uteri was removed for subsequent histological studies and another part was used to evaluate estrogen receptors 1 and 2, cell proliferation (cyclin A1 and A2, cyclin D1, cyclin-dependent kinase inhibitors 1, 1B and 2, antigen identified by the monoclonal antibody Ki67) and angiogenesis (vascular endothelial growth factor, VEGF-A) gene expression.

RESULTS

Late treatment after castration in rats resulted in more developed endometrium, enhanced cell proliferation and estrogen-signalling pathways, particularly the cyclin-related genes Ki67 and VEGF-A, compared to early treatment. Interestingly, these same effects were less intense with genistein compared to those induced by estrogen, especially when genistein was administered late.

CONCLUSION

Our data show that isoflavone renders a lower risk of cancer when compared to estrogen in treatments.

Soybean concentrated extract counteracts oxidative stress in the uterus of rats

OBJECTIVE

To evaluate the effects of soy isoflavone extract in the pro-oxidant/antioxidant balance in the uterus of ovariectomized rats.

METHODS

Twenty 3-month-old adult female Wistar rats were divided into four equal groups: GI: sham-operated (estrous phase); GII: control ovariectomized rats; GIII: ovariectomized rats treated with genistein (50 μg/kg/day) by gavage; GIV: ovariectomized rats subcutaneously treated with estrogen (10 μg/kg/day). After 30 consecutive days of treatment, the rats were euthanized and the uterus removed. The distal thirds of the uterine horns were processed for histomorphometric analyses of endometrial and myometrial thicknesses and glandular area. Other regions of the uteri were kept in liquid nitrogen and subsequently processed for analysis of reactive species quantification (DCF), total antioxidant capacity (TAC) and lipid oxidation status (TBARS). Data were statistically analyzed by one-way ANOVA, complemented by the Tukey-Kramer test (p < 0.05).

RESULTS

GII and GIII exhibited lower endometrial thickness, glandular area and myometrial thickness than GI and GIV, while a higher myometrial thickness was observed in GIV compared with the other groups. Moreover, the isoflavone-treated group showed lower DCF and TBARS compared to GII, and also an improvement of TAC compared to GI and GIV. Despite the significant decrease in TBARS, no significant difference in DCF nor a decrease in TAC were observed in GIV when compared to GII.

CONCLUSION

Our data show that isoflavones improve antioxidant status and counteract oxidative stress, without promoting a trophic effect in the uterus of rats.

Do extracts of oral soybean augment the trophic effect of estrogen on the rat uterus?

OBJECTIVE

To evaluate whether soybean extracts and estrogens present additive effects on adult rat uterus.

METHODS

Fifty ovariectomized rats were randomly divided into five equal groups of ten animals: Control, treated with vehicle; SE46 and SE120, treated with 46 and 120 mg/kg soybean concentrated extract (SE), respectively; EE, treated with conjugated equine estrogens (CE) 50 μg/kg; SE120 + EE, treated with 50 μg/kg (CE) plus 120 mg/kg SE. The substances were administered daily by gavage for 21 consecutive days. Thereafter the animals were weighed and killed by decapitation; trunk blood was collected for hormone determinations. Uteri were removed immediately and fixed in 10% formaldehyde, followed by dehydration, embedding in paraffin and 6-m sections staining with hematoxylin and eosin for histomorphometric analyses of myometrium and endometrium. After ANOVA analysis of the data, the study was complemented with the Tukey-Kramer test for multiple comparisons.

RESULTS

The concentrated extract of soybean at high concentration (SE 120 kg/mg) and estrogens proved to have a trophic effect on the uterus (endometrium and myometrium) of castrated rats. In groups SE120, EE and SE120 + EE, all morphometric parameters examined (number of glands, eosinophils, blood vessels and the glandular area) were increased. No significant addictive effects of soybean extract plus estrogens were detected in the SE120 + EE group.

CONCLUSIONS

Our results indicate that soy extract has a trophic effect on rat uterine structures. Treatment of ovariectomized rats with a concentrated soy extract in combination with conjugated estrogens had no addictive effect on the uterine response.

Histomorphometric analysis of the effects of creatine on rat myometrium

OBJECTIVE

To analyze the myometrial thickness of rats subjected to creatine (Cr) ingestion.

STUDY DESIGN

A total of 14 rats was equally divided into the control group (ConGr) receiving 1 ml potable water and the creatine group (CrGr) subjected to the ingestion of 1.6 g/kg Cr diluted in 1 ml potable water. At the end of 8 weeks, the animals were anesthetized (xylazine and ketamine) and sacrificed, the uteri and ovaries stained with hematoxylin and eosin, the thickness of both the myometrium and the epithelium measured and the follicles counted.

RESULTS

Analysis revealed a significant increase in thickness of the myometrium in the CrGr (272.26 ± 66.71μm) contrasted with that from the ConGr (160.76 ± 35.65μm), CrGr > ConGr (p < 0001).

CONCLUSION

Our data suggest that Cr changed myometrial morphology in rats by enhancing myometrial thickness, but its action mechanism in the smooth muscle is still unclear.