Metformin and exenatide upregulate hepatocyte nuclear factor-4α, sex hormone binding globulin levels and improve hepatic triglyceride deposition in polycystic ovary syndrome with insulin resistance rats

Expanding therapeutic horizons: glucagon-like peptide-1 receptor agonists and sodium glucose transporter-2 inhibitors in poly cystic ovarian syndrome: a comprehensive review including systematic review and network meta-analysis of randomized clinical trials

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex endocrine characterized by hyperandrogenism, hormonal imbalances, and metabolic disruptions, leading to reproductive complications and increased risk of cardiometabolic diseases. While lifestyle modifications are the cornerstone of PCOS management, pharmacological interventions, including metformin, oral contraceptives, and anti-androgens, are commonly utilized. Recently, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) have shown promising results in PCOS management.

METHODS

This study conducted a comprehensive review of randomized clinical trials evaluating the effects of GLP-1 RAs and SGLT2is in women with PCOS. A systematic literature search was performed, and network meta-analysis using random-effects model that generated mixed treatment comparison estimates was employed to assess the comparative efficacy of these drug classes on clinical (menstrual frequency, pregnancy rate and proportion of patients with regular menstrual cycles), anthropometric, hormonal, and metabolic parameters. Additionally, a systematic review of preclinical studies investigating GLP-1 RAs and SGLT2is in animal models of PCOS was undertaken.

RESULTS

This comprehensive meta-analysis included 27 RCTs (1642 participants). GLP-1 RAs (alone and in combination with metformin) were observed to improve menstrual frequencies. GLP-1 RAs showed significant reductions in all anthropometric parameters, while SGLT2is was observed to improve wait hip ratio (WHR) and android gynoid fat (AGF) ratio (in addition to reduced body weight observed with SGLT2is/metformin combination). Reductions in WHR and AGF ratio were better with SGLT2is compared to GLP-1 RAs. The combination of GLP-1 RAs and SGLT2is was observed to have superior efficacy in reducing body weight, percent fat mass, and AGF ratio compared to GLP-1 RAs alone. Regarding hormonal parameters, GLP-1 RAs were observed with significant improvement in free androgen index (FAI), free testosterone, androstenedione, and sex hormone binding globulin levels. SGLT2is was observed with significant improvements in FAI and total testosterone, outperforming GLP-1 RAs in reducing these parameters. Regarding metabolic parameters, GLP-1 RAs significantly improved triglycerides, markers of insulin resistance and fasting and postprandial plasma glucose. SGLT2is was associated with significant improvements in homeostatic model assessment for insulin resistance (HOMA-IR) and fasting plasma glucose, and in combination with metformin, SGLT2is significantly improved triglycerides. SGLT2is outperformed GLP-1 RAs in reducing LDL cholesterol and HOMA-IR. The combination of SGLT2is and GLP-1 RAs was better than GLP-1 RAs in reducing triglycerides and fasting plasma glucose. However, the strength of evidence for these findings was very low. Systematic assessment of animal studies revealed a potential association of several molecular pathways, including AMPK-α, SIRT1, FDX, PI3K/AKT, endothelial adhesion molecules (VCAM, ICAM, and E-selectin), STAR, and CYP17A1, with the therapeutic effects of GLP-1 RAs and SGLT2is in PCOS. Both drug classes were associated with significant improvements in ovarian morphology in animal studies.

CONCLUSION

This systematic review and meta-analysis advance our understanding of GLP-1 RAs and SGLT2is in PCOS management. While both drug classes demonstrate efficacy in metabolic parameters, their distinct mechanisms offer unique therapeutic advantages. SGLT2is excel in improving hormonal profiles and insulin resistance, whereas GLP-1 RAs show consistent benefits in weight management. The enhanced efficacy of combination therapy suggests a potential paradigm shift in PCOS treatment strategies, moving beyond traditional monotherapy approaches. These findings support the therapeutic potential of both drug classes, individually or combined, in PCOS management, providing a foundation for more personalized treatment approaches.

Advancement in early diagnosis of polycystic ovary syndrome: biomarker-driven innovative diagnostic sensor

Polycystic ovary syndrome (PCOS) is a heterogeneous multifactorial endocrine disorder that affects one in five women around the globe. The pathology suggests a strong polygenic and epigenetic correlation, along with hormonal and metabolic dysfunction, but the exact etiology is still a mystery. The current diagnosis is mostly based on Rotterdam criteria, which resulted in a delayed diagnosis in most of the cases, leading to unbearable lifestyle complications and infertility. PCOS is not new; thus, constant efforts are made in the field of biomarker discovery and advanced diagnostic techniques. A plethora of research has enabled the identification of promising PCOS diagnostic biomarkers across hormonal, metabolic, genetic, and epigenetic domains. Not only biomarker identification, but the utilization of biosensing platforms also renders effective point-of-care diagnostic devices. Artificial intelligence also shows its power in modifying existing image-based analysis, even developing symptom-based prediction systems for the early diagnosis of this multifaceted disorder. This approach could affect the future management and treatment direction of PCOS, decreasing its severity and improving the reproductive life of women. The rationale of the current review is to identify the advancements in understanding the pathophysiology through biomarker discovery and the implementation of modern analytical techniques for the early diagnosis of PCOS.

Metformin in gynecological disorders: pathogenic insights and therapeutic implications

Metformin, the most widely used anti-diabetic drug, has been demonstrated to exert various effects, including antioxidant, anti-inflammatory, anti-tumor, and cardioprotective properties. Due to its affordability and low toxicity profile, metformin is increasingly used to prevent or treat a wide range of gynecological disorders, as evidenced by epidemiological studies, clinical trials, and animal and in vitro studies. Trial findings for non-cancer conditions such as endometriosis, premature ovarian failure (POF), and uterine fibroids remain controversial and insufficient. However, most current clinical trials for polycystic ovarian syndrome (PCOS) and gynecological malignancies are ongoing phase II-III trials. The pharmacological effects of metformin have been shown to target the insulin-like growth factor (IGF), AMP-activated protein kinase (AMPK), phosphatidylinositol 3-kinase (PI3K)/AKT, MAPK, NF-κB, and other signal transduction pathways, highlighting its potential in the treatment of gynecological disorders. In this review, we discuss the biological impacts of metformin and the mechanisms of action pertinent to the treatment of different gynecological disorders.

The Beneficial Effects of GLP-1 Receptor Agonists Other than Their Anti-Diabetic and Anti-Obesity Properties

As an incretin hormone, Glucagon-like peptide-1 (GLP-1) has obvious effects on blood glucose regulation and weight loss. GLP-1 receptor (GLP-1R) agonists are synthetic products that have similar effects to GLP-1 but are less prone to degradation, and they are widely used in the treatment of type 2 diabetes and obesity. In recent years, different beneficial effects of GLP-1R agonists were discovered, such as reducing ischemia-reperfusion injury, improving the function of various organs, alleviating substance use disorder, affecting tumorigenesis, regulating bone metabolism, changing gut microbiota composition, and prolonging graft survival. Therefore, GLP-1R agonists have great potential for clinical application in various diseases. Here, we briefly summarized the beneficial effects of GLP-1R agonists other than the anti-diabetic and anti-obesity effects.

Comparative effects of the antioxidant glutathione with metformin and Diane-35 on hormonal, metabolic, and inflammatory indicators in a DHEA-induced PCOS rat model

OBJECTIVE

Comparison of hormonal, metabolic and inflammatory markers of glutathione with metformin and Diane-35 in a rat model of PCOS induced by dehydroepiandrosterone.

METHODS

Twenty-five female rats were randomized into four groups. Group 1 was administered a subcutaneous dose of 0.2 ml saline/day. Group 2 was given 0.2 ml of 1% carboxymethyl cellulose (CMC)/day orally for 28 days. A PCOS model was established with DHEA in rats. Group 3 was given 4.5 mg/kg/day of Diane-35 orally dissolved in 1% CMC for 28 days. Group 4 was given 300 mg/kg/day of metformin orally dissolved in 1 ml of saline for 28 days, and Group 5 was administered 100 mg/kg of glutathione intraperitoneally on days 35, 42, and 49. On day 56, the rats were sacrificed. Serum markers and follicle count were examined.

RESULTS

Serum IL-6, hs-CRP, insulin, testosterone, SHBG, and MDA values were significantly lower in the glutathione group than in the PCOS group (p = 0.0006, p = 0.023, p = 0.0082, p = 0.0007, p = 0.0048, and p < 0.0001, respectively).The number of all follicles was similar between the control and glutathione groups (p < 0.05). When we compared the other groups with the PCOS group, the number of primary, secondary, atretic, and cystic follicles was significantly lower in the metformin and glutathione groups. The number of primordial and antral follicles was significantly higher than in the PCOS group.

CONCLUSIONS

Glutathione plays anti-inflammatory and antioxidant roles, similar to metformin, by lowering serum IL-6, insulin, testosterone, CRP, and MDA levels; decreasing atretic/cystic follicle count; and improving antral follicle count and folliculogenesis in PCOS patients.

Diverse Applications of the Anti-Diabetic Drug Metformin in Treating Human Disease

Metformin is a commonly used drug for treating type 2 diabetes. Metformin is an inexpensive drug with low/no side effects and is well tolerated in human patients of different ages. Recent therapeutic strategies for human disease have considered the benefits of drug repurposing. This includes the use of the anti-diabetic drug metformin. Accordingly, the anti-inflammatory, anti-cancer, anti-viral, neuroprotective, and cardioprotective potentials of metformin have deemed it a suitable candidate for treating a plethora of human diseases. As results from preclinical studies using cellular and animal model systems appear promising, clinical trials with metformin in the context of non-diabetes-related illnesses have been started. Here, we aim to provide a comprehensive overview of the therapeutic potential of metformin in different animal models of human disease and its suggested relationship to epigenetics and ailments with epigenetic components.

Impact of high-fructose diet and metformin on histomorphological and molecular parameters of reproductive organs and vaginal microbiota of female rat

There are limited data on the effects of a high-fructose diet on the female reproductive system. Although metformin has some functional effects on female fertility, its reproductive outcome on high fructose diet-induced metabolic syndrome is unclear. The aim of the present study is to evaluate the impact of a high fructose diet on histomorphological and molecular parameters of the reproductive organs and vaginal microbiota as well as the treatment potential of metformin. Wistar albino rats were used in the study. The metabolic syndrome model was induced by a high-fructose diet in rats for 15 weeks. Metformin was orally administered once a day for the last 6 weeks. The high-fructose diet increased blood glucose, triglycerides, insulin, and ovarian testosterone levels; however, it reduced ovarian aromatase levels and follicle numbers and caused uterine inflammation. The high-fructose diet-induced molecular abnormalities on ovarian tissue were demonstrated by the downregulation of ovarian insulin signaling pathway proteins and dysregulation of ovarian mitogenic and apoptotic pathway proteins. A high-fructose diet caused vaginal dysbiosis, metformin increased probiotic bacteria in the vaginal microbiota. Our results revealed that metformin improves ovarian impairments by modulating hormonal balance, insulin level, mapk, and apoptotic signaling molecules, as well as regulating the vaginal microbiota.

Polycystic ovary syndrome: Current scenario and future insights

Polycystic ovary syndrome (PCOS) prevails in approximately 33% of females of reproductive age globally. Although the root cause of the disease is unknown, attempts are made to clinically manage the disturbed hormone levels and symptoms arising due to hyperandrogenism, a hallmark of PCOS. This review presents detailed insights on the etiology, risk factors, current treatment strategies, and challenges therein. Medicinal agents currently in clinical trials and those in the development pipeline are emphasized. The significance of the inclusion of herbal supplements in PCOS and the benefits of improved lifestyle are also explained. Last, emerging therapeutic targets for treating PCOS are elaborated. The present review will assist the research fraternity working in the concerned domain to access significant knowledge associated with PCOS.

Effects of GLP1RAs on pregnancy rate and menstrual cyclicity in women with polycystic ovary syndrome: a meta-analysis and systematic review

PURPOSE

This study was aimed to assess the effectiveness of Glucagon-like peptide 1 receptor agonists on pregnancy rate, menses, anthropometric and hormonal parameters in PCOS patients.

METHODS

We conducted searches of the published literature in PubMed, EMBASE, Cochrane Library, Web of Science up to September 2022. Data from randomized controlled trials were obtained to assess the effects of GLP1RAs in PCOS women. Weighted mean difference, standardized mean difference, and risks ratio were employed for effect size estimation using a random-effects model.

RESULTS

A total of 840 patients with 469 individuals in GLP1RAs group and 371 individuals in control group from 11 RCTs were included. GLP1RAs usage was associated with an improvement in natural pregnancy rate (RR: 1.72, 95% CI 1.22 to 2.43, P = 0.002, I2 = 0%) and menstrual regularity (SMD: 1.72, 95% CI 0.60 to 2.85, P < 0.001, I2 = 95.6%). There were no statistically significant differences in total pregnancy rate, IVF pregnancy rate between two groups, but total PR elevated in a short time after GLP1RAs as shown in subgroup analysis. Randomization to GLP1RAs treatment was associated with great improvement in HOMA-IR, BMI, WC, SHBG and a slight reduction in TT compared to control group. A decrease in TBF was seen in European population. GLP1RAs monotherapy was not superior to metformin when it came to fT, DHEAS, FAI.

CONCLUSIONS

Prescription of GLP1RAs improves natural pregnancy rate, menstrual cyclicity and insulin sensitivity, anthropometrics, hormonal indexes in PCOS women.

Pioglitazone can improve liver sex hormone-binding globulin levels and lipid metabolism in polycystic ovary syndrome by regulating hepatocyte nuclear factor-4α

Polycystic ovary syndrome (PCOS) is a common reproductive and metabolic disorder that is closely correlated with insulin resistance. Sex hormone-binding globulin (SHBG) is an important carrier for regulating androgen activity and is affected by insulin level, which is related to metabolic abnormalities and long-term prognosis of PCOS. Insulin sensitizer pioglitazone can improve the SHBG level and dyslipidaemia in PCOS, but the mechanism remains unclear. We investigated liver SHBG expression, liver lipid levels, and the effects and potential mechanisms of pioglitazone on reproductive and metabolic disorders in a rat model of polycystic ovary syndrome with insulin resistance (PCOS-IR). PCOS-IR was induced by letrozole and a high-fat diet. Metformin was used as a positive control. Additionally, dihydrotestosterone and oleic acid combined with palmitic acid were used to induce the HepG2 cell models with IR. The cells were exposed to pioglitazone alone or in combination with a hepatocyte nuclear factor (HNF)- 4α inhibitor. Changes in biochemical characteristics were analysed using an enzyme-linked immunosorbent assay. Vaginal smears were used to analyse the oestrous cycle, and ovarian histology was used to analyse the changes in ovarian morphology. The degree of IR in vivo and in vitro was measured using the hyperinsulinaemic-euglycaemic clamp and glucose oxidase techniques. The levels of key anabolism-related proteins, including SHBG, HNF-4α, and peroxidase proliferator-activated receptor (PPAR-γ), were measured using western blots. Pioglitazone and metformin significantly increased the SHBG levels in the sera and livers. Compared to metformin, pioglitazone significantly improved the lipid droplet deposition, triglyceride (TG) and total cholesterol (TC) levels, HNF-4α protein expression, and weights of the livers in the PCOS-IR rats. After applying pioglitazone with an HNF-4α inhibitor in the PCOS-IR cell models, we found that pioglitazone may increase SHBG and improve IR, TG, and TC levels by upregulating HNF-4α. Similar to metformin, pioglitazone also restored the oestrous cycle and ovarian morphology, ameliorated IR and hyperandrogenaemia in the PCOS-IR rats. Our findings hint at the value of HNF-4α in the treatment of PCOS by PIO, which could shed light on potential targets that may be used in treatments for PCOS with metabolic disorders.

The association between serum sex hormone-binding globulin changes during progestin-primed ovarian stimulation and embryo outcomes: a retrospective cohort study

Objective: This study is aimed to examine the associations between embryo outcomes and serum sex hormone-binding globulin (SHBG) changes during progestin-primed ovarian stimulation (PPOS) protocols in IVF/ICSI cycles.Research methods: This study included 2790 eligible consecutive cycles of patients aged 21-53 years undergoing PPOS treatment. Multivariable linear regression analysis was performed to explore the association between SHBG changes and embryo outcomes.Results of the study: Our results showed that the SHBG-increase rate on the HCG day and in the late follicular phase were positively and linearly correlated with available embryos in day3, with adjusted regression coefficients (β) for the SHBG-increase rate on the HCG day, in the late follicular phase were 0.6 (0.4, 0.9), 0.4 (0.2, 0.6), but in the middle follicular phase and in the early follicular phase, this correlation was not significant (p > 0.05).Conclusion: Our results indicate that serum SHBG increment may serve as a biomarker of the developmental potential of the oocytes from patients undergoing the PPOS protocol.

Effect of Sex Hormone-Binding Globulin on Polycystic Ovary Syndrome: Mechanisms, Manifestations, Genetics, and Treatment

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases causing infertility in women of childbearing age. It is characterized by hyperandrogenemia (HA), chronic anovulation, and polycystic ovary morphology (PCOM). Most women with PCOS have metabolic abnormalities. Sex hormone-binding globulin (SHBG), a transport carrier that binds estrogen and androgens and regulates their biological activity, is usually used as an indicator of hyperandrogenism in women with PCOS. Low serum SHBG levels are considered a biomarker of metabolic abnormalities and are associated with insulin resistance (IR), HA, and abnormal glucose and lipid metabolism in PCOS patients. SHBG is also related to the long-term prognosis of PCOS, whereas SHBG gene polymorphism is associated with PCOS risk. In addition, the administration of metformin (MET), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), thiazolidinediones (TZDs), compound oral contraceptives (COCs), as well as nutrient supplements such as inositol (MI), vitamin D, and synbiotics can regulate SHBG levels to ameliorate PCOS complications and improve prognosis. This review focuses on the interaction between SHBG and various PCOS complications as well as the regulation of SHBG by various drugs and nutrients and its therapeutic effects on PCOS.

Exenatide improves hepatocyte insulin resistance induced by different regional adipose tissue

Obesity is resulted from energy surplus and is characterized by abnormal adipose tissue accumulation and/or distribution. Adipokines secreted by different regional adipose tissue can induce changes in key proteins of the insulin signaling pathway in hepatocytes and result in impaired hepatic glucose metabolism. This study aimed to investigate whether exenatide affects key proteins of IRS2/PI3K/Akt2 signaling pathway in hepatocytes altered by the different regional fat depots. Six non-obese patients without endocrine diseases were selected as the research subjects. Their subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT)were co-cultured with HepG2 cells in the transwell chamber. In the presence or absence of exenatide, adipokines content in the supernatant of each experimental group was detected by ELISA. In addition, HepG2 cells in each co-culture group with and without insulin were collected, and the expression of key proteins IRS2, p-IRS2(S731), PI3K-p85, Akt2, and p-Akt2(S473) was detected by western blotting (WB). The results showed that the adipokines IL-8, MCP-1, VEGF, and sTNFR2 in the supernatant of HepG2 cells induced by different regional adipose tissue were significantly higher than those in the HepG2 group, and VAT released more adipokines than SAT. Furthermore, these adipokines were significantly inhibited by exenatide. Importantly, the different regional fat depot affects the IRS2/PI3K/Akt2 insulin signaling pathway of hepatocytes. Exenatide can up-regulate the expression of hepatocyte proteins IRS2, PI3K-p85, p-Akt2(S731) inhibited by adipose tissue, and down-regulate the expression of hepatocyte proteins p-IRS2(S731) promoted by adipose tissue. The effect of VAT on the expression of these key proteins in hepatocytes is more significant than that of SAT. But there was no statistical difference in the expression of Akt2 protein among each experimental group, suggesting that exenatide has no influence on the expression of Akt2 protein in hepatocytes. In conclusion, exenatide may improve hepatic insulin resistance (IR) by inhibiting adipokines and regulating the expression of key proteins in the IRS2/PI3K/Akt2 pathway.