High-refined carbohydrate diet leads to polycystic ovary syndrome-like features and reduced ovarian reserve in female rats

Single microcystin exposure impairs the hypothalamic-pituitary-gonadal axis at different levels in female rats

Microcystin (MC) is most common cyanobacterial toxin. Few studies have evaluated the MC effects on the hypothalamic-pituitary-gonadal (HPG) axis and metabolic function. In this study, we assessed whether MC exposure results in HPG axis and metabolic changes. Female rats were exposed to a single dose of MC at environmentally relevant levels (5, 20 and 40 μg/kg). After 24 h, we evaluated reproductive and metabolic parameters for 15 days. MC reduced the hypothalamic GnRH protein expression, increased the pituitary protein expression of GnRHr and IL-6. MC reduced LH levels and increased FSH levels. MC reduced the primary follicles, increased the corpora lutea, elevated levels of anti-Müllerian hormone (AMH) and progesterone, and decreased estrogen levels. MC increased ovarian VEGFr, LHr, AMH, ED1, IL-6 and Gp91-phox protein expression. MC increased uterine area and reduced endometrial gland number. A blunted estrogen-negative feedback was observed in MC rats after ovariectomy, with no changes in LH levels compared to intact MC rats. Therefore, these data suggest that a MC leads to abnormal HPG axis function in female rats.

Irpex lacteus polysaccharide exhibits therapeutic potential for ovarian fibrosis in PCOS rats via the TGF-β1/smad pathway

Polycystic ovarian syndrome (PCOS) is one of the commonest endocrinopathies in childbearing women. The research was conducted to assess the impact of Irpex lacteus polysaccharide (ILP, 1000 mg/kg) on the letrozole (1 mg/kg)-induced PCOS model in female rats. Metformin (Met, 265 mg/kg) as the positive control. The study suggested that ILP restored the estrous cycle in rats with PCOS as well as lowered relative ovarian weight and body weight, in comparison to normal. Rats with PCOS showed improvement in ovarian structure and fibrosis when given ILP. ILP decreased the testosterone (T), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC), luteinizing hormone (LH), homeostasis model assessment-insulin resistance (HOMA-IR), fasting blood glucose (FBG), and insulin (INS) levels and elevated the follicle-stimulating hormone (FSH) and estrogen (E2) levels in PCOS rats. In addition, ILP increased the content of superoxide dismutase (SOD) in serum and the antioxidant enzymes (Prdx3, Sod1, Gsr, Gsta4, Mgst1, Gpx3, Sod2 and Cat) expression levels in the ovaries and decreased the serum expression of malondialdehyde (MDA). In addition, ILP treatment slowed down the process of the fibrosis-associated TGF-β1/Smad pathway and downregulated α-smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF) levels in PCOS rats ovaries. According to these findings, ILP may be able to treat letrozole-induced PCOS in rats by ameliorating metabolic disturbances, sex hormone levels, oxidative stress, and ovarian fibrosis.

Subacute high-refined carbohydrate diet leads to abnormal reproductive control of the hypothalamic-pituitary axis in female rats

We previously reported that female rats placed on a diet containing refined carbohydrates (HCD) resulted in obesity and reproductive abnormalities, such as high serum LH concentration and abnormal ovarian function. However, the impacts at the hypothalamic-pituitary (HP) function, specifically regarding pathways linked to reproductive axis modulation are unknown. In this study, we assessed whether subacute feeding with HCD results in abnormal reproductive control in the HP axis. Female rats were fed with HCD for 15 days and reproductive HP axis morphophysiology was assessed. HCD reduced hypothalamic mRNA expression (Kiss1, Lepr, and Amhr2) and increased pituitary LHβ+ cells. These changes likely contribute to the increase in serum LH concentration observed in HCD. Blunted estrogen negative feedback was observed in HCD, with increased kisspeptin protein expression in the arcuate nucleus of the hypothalamus (ARH), lower LHβ+ cells and LH concentration in ovariectomized (OVX)+HCD rats. Thus, these data suggest that HCD feeding led to female abnormal reproductive control of HP axis.

Obesity-induced inflammatory miR-133a mediates apoptosis of granulosa cells and causes abnormal folliculogenesis

Obesity has been reported to promote disordered folliculogenesis, but the exact molecular mechanisms are still not fully understood. In this study, we find that miR-133a is involved in obesity-induced follicular development disorder. After feeding with a high-fat diet (HFD) and fructose water for nine weeks, the mouse body weight is significantly increased, accompanied by an inflammatory state and increased expression of miR-133a in the adipose tissues and ovaries as well as accelerated follicle depletion. Although miR-133a is increased in the fat and ovaries of HFD mice, the increased miR-133a in the HFD ovaries is not derived from exosome transferred from obese adipose tissues but is synthesized by ovarian follicular cells in response to HFD-induced inflammation. In vivo experiments show that intrabursal injection of miR-133a agomir induces a decrease in primordial follicles and an increase in antral follicles and atretic follicles, which is similar to HFD-induced abnormal folliculogenesis. Overexpression of miR-133a modestly promotes granulosa cell apoptosis by balancing the expression of anti-apoptotic proteins such as C1QL1 and XIAP and pro-apoptotic proteins such as PTEN. Overall, this study reveals the function of miR-133a in obesity-induced ovarian folliculogenesis dysfunction and sheds light on the etiology of female reproductive disorders.

High-refined carbohydrate diet alters different metabolic functions in female rats

A diet containing refined carbohydrate (HCD) caused obesity and white adipose tissue (WAT) abnormalities, but it is unclear if HCD is linked with other metabolic dysfunctions in female models. Thus, we assessed whether HCD results in WAT, pancreas, liver, skeletal muscle (SM) and thyroid (TH) abnormalities in female rats. Female rats were fed with HCD for 15 days and metabolic morphophysiology, inflammation, oxidative stress (OS), and fibrosis markers were assessed. HCD rats presented large adipocytes, hyperleptinemia, and WAT OS. HCD caused irregular glucose metabolism, low insulin levels, and large pancreatic isle. Granulomas, reduced glycogen, and OS were observed in HCD livers. HCD caused hypertrophy and increased in glycogen in SM. HCD caused irregular TH morphophysiology, reduced colloid area and high T3 levels. In all selected tissues, inflammation and fibrosis were observed in HCD rats. Collectively, these data suggest that the HCD impairs metabolic function linked with irregularities in WAT, pancreas, liver, SM and TH in female rats.

A High-Fat and High-Carbohydrate Diet Promotes Reminiscent Hallmarks of an Aging Ovary in the Rabbit Model

The primary definition of ovarian aging refers to the loss of follicles. Moreover, the aging of the microenvironment in ovaries, specifically affecting the follicles, may reveal deterioration with advancing age. Besides aging, metabolic disorders associated with hypercaloric diets may affect ovarian health and manifest characteristics associated with premature aging. In this study, we used 10-week-old chinchilla rabbits fed with a high-fat and high-carbohydrate diet (HFCD) until 25 weeks of age to explore hallmarks of reminiscent ovarian aging. The HFCD diet appeared to affect the ovarian reserve, reflected in a significant decrease in primordial follicles. Likewise, Sudan black stain detection revealed substantial differences in the deposits of lipofuscin in the interstitial glands of HFCD-fed rabbits compared to controls, constituting a "hallmark" of aging. The HFCD showed no induced changes in the expression of SOD 2 in the interstitial gland; however, surface epithelium cells were greater expressed. Besides this, the HFCD induced nuclear translocation of NF-ΚΒ p65 factor transcription in surface epithelium cells. We conclude that an HFCD induces a greater accumulation of senescence cells in the interstitial gland, promoting characteristics reminiscent of ovarian aging. However, the activation mechanism of NF-KB caused by an HFCD, which may be stress-responsive and generated by the interstitial gland, requires further study.

Surgical and nutritional interventions for endometrial receptivity: A case report and review of literature

BACKGROUND

Polycystic ovary syndrome (PCOS) is an endocrine disease that combines metabolic, reproductive, and psychological dysfunctions. Ovulation disorders and impaired endometrial receptivity in PCOS can cause infertility. Insulin resistance (IR) is a pathological state of inadequate response to insulin that affects reproduction in PCOS, as damage caused by IR at the endometrial level becomes an obstacle for embryo implantation. Reversing IR resulted in spontaneous pregnancies in PCOS patients, indicating that metabolic corrections improve endometrial dysfunctions. Mesenchymal stem-cell treatment has also corrected endometrial quality and lead to pregnancies in patients with Asherman’s syndrome. We propose a combination of nutritional intervention with the surgical placement of stem cells to improve endometrial quality to achieve pregnancy in a PCOS patient undergoing in vitro fertilization (IVF) treatment.

CASE SUMMARY

After two failed IVF cycles, a metabolic intervention, consisting of a ketogenic diet with daily consumption of 50 g of carbohydrates (CH), was indicated until pregnancy. Metabolic Syndrome was assessed using the Harmonizing Definition (3 of 5 pathologies: Central obesity, hypertension, hyperglycemia, hypertriglyceridemia, and dyslipidemia), and the Homeostatic Model Assessment of IR (HOMA-IR) was used to measure the level of IR. Once IR improved, endometrial quality improved. However, two day 5-thawed embryos (euploid, donated oocyte–partner's sperm) failed to implant, suggesting endometrial quality improvement was insufficient. Therefore, transmyometrial implantation of mesenchymal stem cells from the stromal vascular fraction of adipose tissue was performed to enrich the endometrial stem cell niche. Minimal endometrial mean thickness for embryo transfer (6.9 mm) was achieved three months after stem cell treatment and continuous dietary control of IR. Two euploid-day 5-thawed embryos (donated oocyte–partner's sperm) were transferred, and embryo implantation was confirmed on day 14 by β-hCG serum levels. Currently, a 37 wk baby girl is born.

CONCLUSION

In PCOS, endometrial quality can be improved by combining nutrient-based metabolic correction with endometrial stem cell niche enrichment.

The Effect of Alternating High-Sucrose and Sucrose Free-Diets, and Intermittent One-Day Fasting on the Estrous Cycle and Sex Hormones in Female Rats

Relationships between diet, sex hormone concentrations, and the estrous cycle are important from the perspective of infertility and estrogen-dependent disease prevention and treatment. Four dietary interventions reflecting modern eating behaviors were explored. The study involved 50 female rats divided into five feeding groups. The impact of the amount of sucrose consumed (9% and 18% of the dietary energy content), alternating high-sucrose and sucrose-free diets, and a high-sucrose diet combined with intermittent one-day fasting on the estrous cycle and sex hormone concentrations in female rats was assessed. Even low amounts of dietary sucrose (9% of the dietary energy content) were found to lead to increased estradiol (E2) concentrations and decreased progesterone (Pg) concentrations. A high-sucrose diet, even when periodically applied, additionally led to a reduced concentration of luteinizing hormone (LH). The largest changes in the hormones tested were observed with one-day fasting coupled with the high-sucrose diet; in addition, the estrous phase was shortened and the estrous cycle was disrupted. The results of this study show that both the amount of dietary sucrose and also its uptake pattern affect the estrous cycle and sex hormone concentrations in female rats.

Distinctions in PCOS Induced by Letrozole Vs Dehydroepiandrosterone With High-fat Diet in Mouse Model

Polycystic ovarian syndrome (PCOS) is a complex health condition associated with metabolic disturbances and infertility. Recent data suggest that the prevalence of PCOS is increasing among women globally, although the etiology of these trends is undefined. Consequently, preclinical models that better reflect the biology of PCOS are urgently needed to facilitate research that can lead to the discovery of prevention strategies or improved management. The existing animal models have several limitations as they do not reflect all the PCOS features metabolically and/or phenotypically. Therefore, there is no clear consensus on the use of appropriate animal model and selection of the most appropriate PCOS-inducing agent. To that end, we have established a Swiss albino mouse model of PCOS based on 3 weeks of daily treatment with letrozole (50 μg/day; intraperitoneal) and dehydroepiandrosterone (DHEA, 6 mg/100 g body weight; subcutaneous) in 5-week-old female mice fed on normal or high-fat diet (HFD). Mice were regularly assessed for body weight, blood glucose, and estrous cycle. Three weeks after drug administration, mice were sacrificed and assessed for blood-based metabolic parameters as well as ovarian function. Our results indicate that DHEA combined with HFD produces changes mimicking those of clinical PCOS, including elevated serum testosterone and luteinizing hormone, dyslipidemia, poor ovarian microenvironment, and development of multiple ovarian cysts, recapitulating cardinal features of PCOS. In comparison, normal diet and/or letrozole produced fewer features of PCOS. The data from the experimental models presented here can improve our understanding of PCOS, a growing concern in women's health.

Effect of macronutrient and micronutrient manipulation on avian blood glucose concentration: A systematic review

Animals with natural protections against diabetes complications may provide clues to improve human health. Birds are unique in their ability to avoid hyperglycemia-associated complications (e.g., glycation and oxidative stress) despite having naturally high blood glucose (BG) concentrations. This makes them useful models to elucidate strategies to prevent and/or treat diabetes-related complications in mammals. As diet plays a key role in BG concentration and diabetes risk, this systematic review aimed to summarize the effects of macro and micronutrient manipulation on avian BG. Three databases were searched (PubMed, SCOPUS, and Web of Science) for articles that met inclusion criteria: altered at least one nutrient and measured BG in at least one avian species. The search yielded 91 articles that produced 128 datasets (i.e., one nutrient manipulation in one sample). Across all macronutrient manipulations (n = 69 datasets), 62% reported no change in BG and 23% measured an increase (p < 0.001). Within the macronutrient groups (carbohydrate, lipid, protein, and mixed) most datasets showed no change in BG (67%, 62%, 52%, and 86%, respectively). Across micronutrient manipulations (n = 59 datasets), 51% demonstrated no change and 41% decreased BG (p < 0.001). While manipulations that altered vitamin intake largely produced no change in BG (62%), 48% of datasets examining altered mineral intake found no change and 46% decreased BG. Chromium was the most studied micronutrient (n = 24 datasets), where 67% of datasets reported a decrease in BG. These results suggest birds are largely able to maintain blood glucose homeostasis in response to altered nutrient intake indicative of dietary flexibility.

EGCG exposure during pregnancy affects uterine histomorphology in F1 female mice and the underlying mechanisms

Although epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea, has been shown to have many benefits, the effect of EGCG exposure in utero on adult uterine development is unclear. In this study, pregnant C57BL/6 mice were exposed to 1 mg/kg body weight (bw) EGCG dissolved in drinking water from gestational days 0.5-16.5. A significant decrease in uterine weight was observed in the adult female mice, accompanied by uterine atrophy, inflammation, and fibrosis in the endometrium. Uterine atrophy was attributed to the thinning of the endometrial stromal layer and a significant reduction in endometrial cell proliferation. The expression levels of related proteins in the NF-κB and RAF/MEK/ERK signaling pathways were significantly increased, which might be responsible for the occurrence of inflammation. Activation of the transforming growth factor beta (TGF-β1)/Smad signaling pathway might be involved in the development of endometrial fibrosis. The changes in the expression of estrogen receptor α, β (ERα, ERβ), progesterone receptor (PGR), and androgen receptor (AR) might lead to changes in the aforementioned signaling pathways. The promoter region methylation level of Esr2 was increased, and the expression of DNMT3A was evaluated. Our study indicates a risk of EGCG intake during pregnancy affecting uterine development in offspring.

Tributyltin and high-refined carbohydrate diet lead to metabolic and reproductive abnormalities, exacerbating premature ovary failure features in the female rats

Exposure to the obesogen tributyltin (TBT) alone or high carbohydrate diet (HCD) alone leads to obesity and reproductive complications, such as premature ovary failure (POF) features. However, little is known about interactions between TBT and nutrition and their combined impact on reproduction. In this study, we assessed whether acute TBT and HCD exposure results in reproductive and metabolic irregularities. Female rats were treated with TBT (100 ng/kg/day) and fed with HCD for 15 days and metabolic and reproductive outcomes were assessed. TBT and HCD rats displayed metabolic impairments, such as increased adiposity, abnormal lipid profile and triglyceride and glucose (TYG) index, worsening adipocyte hypertrophy in HCD-TBT rats. These metabolic consequences were linked with reproductive disorders. Specifically, HCD-TBT rats displayed irregular estrous cyclicity, high follicle-stimulating hormone (FSH) levels, low anti-Müllerian hormone (AMH) levels, reduction in ovarian reserve, and corpora lutea (CL) number, with increases in atretic follicles, suggesting that HCD-TBT exposure exacerbated POF features. Further, strong negative correlations were observed between adipocyte hypertrophy and ovarian reserve, CL number and AMH levels. HCD-TBT exposure resulted in reproductive tract inflammation and fibrosis. Collectively, these data suggest that TBT plus HCD exposure leads to metabolic and reproductive abnormalities, exacerbating POF features in female rats.

Improvement of Obesity and Dyslipidemic Activity of Amomum tsao-ko in C57BL/6 Mice Fed a High-Carbohydrate Diet

Amomum tsao-ko Crevost et Lemaire (Zingiberaceae) is a medicinal herb found in Southeast Asia that is used for the treatment of malaria, abdominal pain, dyspepsia, etc. The aim of this study was to investigate the effect of an ethanol extract of Amomum tsao-ko (EAT) on obesity and hyperlipidemia in C57BL/6 mice fed a high-carbohydrate diet (HCD). First, the mice were divided into five groups (n = 6/group) as follows: normal diet, HCD, and HCD+EAT (100, 200, and 400 mg/kg/day), which were orally administered with EAT daily for 84 days. Using microcomputed tomography (micro-CT) analysis, we found that EAT inhibited not only body-weight gain, but also visceral fat and subcutaneous fat accumulation. Histological analysis confirmed that EAT decreased the size of fat tissues. EAT consistently improved various indices, including plasma levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein, high-density lipoprotein, atherogenic index, and cardiac risk factors, which are related to dyslipidemia—a major risk factor for heart disease. The contents of TC and TG, as well as the lipid droplets of HCD-induced hepatic accumulation in the liver tissue, were suppressed by EAT. Taken together, these findings suggest the possibility of developing EAT as a therapeutic agent for improving HCD-induced obesity and hyperlipidemia.

Subacute cadmium exposure disrupts the hypothalamic-pituitary-gonadal axis, leading to polycystic ovarian syndrome and premature ovarian failure features in female rats

Cadmium (Cd), a toxic heavy metal, is a known endocrine disruptor that is associated with reproductive complications. However, few studies have explored the effects of Cd exposure on features of polycystic ovary syndrome (PCOS) and premature ovary failure (POF). In this study, we assessed whether doses found in workers occupationally exposed to Cd and subacute exposure result in hypothalamic-pituitary-gonadal (HPG) axis and other irregularities. We administered CdCl₂ to female rats (100 ppm in drinking water for 30 days) and then assessed Cd levels in the blood, HPG axis and uterus. Metabolic features, HPG axis function, reproductive tract (RT) morphophysiology, inflammation, oxidative stress (OS), and fibrosis were evaluated. Cd exposure increased Cd levels in the serum, HPG axis, and uterus. Cd rats displayed metabolic impairments, such as a reduction in adiposity, dyslipidemia, and insulin resistance (IR). Cd exposure also caused improper functioning in the HPG. Specifically, Cd exposure caused irregular estrous cyclicity, abnormal hypothalamic gene expression (upregulated - Kiss1, AR and mTOR; downregulated - Kiss1R, LepR and TNF-α), high LH levels, low AMH levels and abnormal ovarian follicular development, coupled with a reduction in ovarian reserve and antral follicle number was observed, suggesting ovarian depletion. Further, Cd exposure caused a reduction in corpora lutea (CL) and granulosa layer thickness together with an increase in cystic/atretic follicles. In addition, Cd exposure caused RT inflammation, OS and fibrosis. Finally, strong positive correlations were observed between serum, RT Cd levels, IR, dyslipidemia and estrous cycle length, cystic, atretic follicles, LH levels, and RT inflammation. Thus, these data suggest that subacute Cd exposure using doses found in workers occupationally exposed to Cd disrupt the HPG axis function, leading to PCOS and POF features and other abnormalities in female rats.

Early Exposure to High-Sucrose Diet Leads to Deteriorated Ovarian Health

BACKGROUND

The metabolic syndrome (MetS) is correlated with disorders of the reproductive system, such as the polycystic ovary syndrome (PCOS). While consumption of a diet rich in carbohydrates is linked to the development of MetS, it is still unclear if this diet leads to ovarian dysfunction and PCOS.

OBJECTIVES

We investigated the influence of a high-sucrose diet (HSD) on the ovarian milieu of Wistar rats and studied the correlation between high consumption of sugary drinks and the prevalence of PCOS in women.

METHODS

Wistar rats were given a standard laboratory diet (CTR, 10% sucrose, n = 8) or HSD (HSD, 25% sucrose, n = 8) from postnatal day 21 to 120. Animals were evaluated weekly to calculate food intake, feed efficiency and weight gain. Both onset of puberty and estrous cycle were monitored. Metabolic serum biochemistry, organ morphometry and ovarian histology were performed upon euthanasia. In parallel, a fixed-effects multiple linear regression analysis was performed using data from Brazilian states (459 state-year observations) to test the correlation between the consumption of sugar-sweetened beverages (surrogate for HSD intake) and the prevalence of PCOS (surrogate for ovarian dysfunction).

RESULTS

HSD animals showed increased adipose tissue accumulation, hyperglycaemia and insulin resistance when compared to CTR. Interestingly HSD rats also entered puberty earlier than CTR. Moreover, ovaries from HSD animals had an increased number of atretic antral follicles and cystic follicles, which were correlated with the hypertrophy of periovarian adipocytes. Finally, there was a positive correlation between the intake of sugary drinks and prevalence of PCOS in women of reproductive age.

CONCLUSIONS

HSD ingestion leads to ovarian dysfunction in rats and could be correlated with PCOS in women, suggesting these alterations could lead to public health issues. Therefore, we reinforce the deleterious impact of HSD to the ovarian system and suggest that the reduction of added sugars intake could be beneficial to ovarian health.