The effects of rosiglitazone and metformin on oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome

Dissecting the shared genetic architecture between endometriosis and polycystic ovary syndrome

Background

Previous study suggested evidence for coexistence and similarities between endometriosis and polycystic ovary syndrome (PCOS), but it is unclear regarding the shared genetic architecture and causality underlying the phenotypic similarities observed for endometriosis and PCOS.

Methods

By leveraging summary statistics from public genome-wide association studies regarding endometriosis (European-based: N=470,866) and PCOS (European-based: N=210,870), we explored the genetic correlation that shared between endometriosis and PCOS using linkage disequilibrium score regression. Shared risk SNPs were derived using PLACO (Pleiotropic analysis under composite null hypothesis) and FUMA (Functional Mapping and Annotation of Genetic Associations). The potential causal association between endometriosis and PCOS was investigated using two-sample Mendelian randomization (MR). Linkage disequilibrium score for the specific expression of genes analysis (LDSC-SEG) were performed for tissue enrichment analysis. The expression profiles of the risk gene in tissues were further examined.

Results

A positive genetic association was observed between endometriosis and PCOS. 12 significant pleiotropic loci shared between endometriosis and PCOS were identified. Genetic associations between endometriosis and PCOS were particularly enriched in uterus, endometrium and fallopian tube. Two-sample MR analysis further indicated a potential causative effect of endometriosis on PCOS, and vice versa. Microarray and RNA-seq verified the expressions of SYNE1 and DNM3 were significantly altered in the endometrium of patients with endometriosis or PCOS compared to those of control subjects.

Conclusion

Our study indicates the genetic correlation and shared risk genes between PCOS and endometriosis. These findings provide insights into the potential mechanisms behind their comorbidity and the future development of therapeutics.

Association of Serum Selenium and Selenoprotein P with Oxidative Stress Biomarkers in Patients with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age which is characterized by various reproductive and metabolic disorders. Oxidative stress (OS) is now recognized to be involved in the pathogenesis of PCOS which could be targeted in the management of PCOS-related complications. Selenium (Se), as an antioxidant trace element, has been shown to decrease in PCOS patients. This study aimed to investigate the relationship between the Se and selenoprotein P (SELENOP) levels with OS markers in women with PCOS. In this cross-sectional study, 125 females aged 18-45 years diagnosed with PCOS were included. Demographic, clinical, and lifestyle information of participants were obtained using the relevant questionnaires. Fasting blood samples were collected to measure biochemical parameters. Serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activities as well as anthropometric measurements were assessed across tertiles of serum concentrations of Se and SELENOP. Higher serum levels of Se were associated with higher serum TAC levels (β=0.42, P<0.001) and erythrocytes GPx activity (β=0.28, P=0.002) as well as with lower serum TBARS levels (β= -0.26, P=0.003). Similarly, higher serum levels of SELENOP were associated with higher TAC (β=0.32, P<0.001) and erythrocyte GPx activity (β=0.30, P=0.001). SELENOP also showed an inverse association with serum levels of TBARS (β= -0.40, P<0.001). Nevertheless, erythrocytes SOD and CAT activities showed no significant relationships with serum Se and SELENOP concentrations (all P>0.05). The present study found that serum Se and SELENOP levels were inversely associated with TBARS levels and positively associated with TAC levels and erythrocytes GPx activity.

Polycystic Ovary Syndrome and Oxidative Stress-From Bench to Bedside

Oxidative stress (OS) is a condition that occurs as a result of an imbalance between the production of reactive oxygen species (ROS) and the body's ability to detoxify and neutralize them. It can play a role in a variety of reproductive system conditions, including polycystic ovary syndrome (PCOS), endometriosis, preeclampsia, and infertility. In this review, we briefly discuss the links between oxidative stress and PCOS. Mitochondrial mutations may lead to impaired oxidative phosphorylation (OXPHOS), decreased adenosine triphosphate (ATP) production, and an increased production of ROS. These functional consequences may contribute to the metabolic and hormonal dysregulation observed in PCOS. Studies have shown that OS negatively affects ovarian follicles and disrupts normal follicular development and maturation. Excessive ROS may damage oocytes and granulosa cells within the follicles, impairing their quality and compromising fertility. Impaired OXPHOS and mitochondrial dysfunction may contribute to insulin resistance (IR) by disrupting insulin signaling pathways and impairing glucose metabolism. Due to dysfunctional OXPHOS, reduced ATP production, may hinder insulin-stimulated glucose uptake, leading to IR. Hyperandrogenism promotes inflammation and IR, both of which can increase the production of ROS and lead to OS. A detrimental feedback loop ensues as IR escalates, causing elevated insulin levels that exacerbate OS. Exploring the relations between OS and PCOS is crucial to fully understand the role of OS in the pathophysiology of PCOS and to develop effective treatment strategies to improve the quality of life of women affected by this condition. The role of antioxidants as potential therapies is also discussed.

Plasma Lipoprotein(a) Levels in Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis

INTRODUCTION

The polycystic ovary syndrome (PCOS) may represent an important model of lipid alterations. Lipoprotein(a) [Lp(a)] has emerged as a new marker of cardiovascular risk.

AIM

The main objective of this meta-analysis was to analyze the available evidence on Lp(a) levels in patients with PCOS compared to a control group.

METHODS

This meta-analysis was performed according to PRISMA guidelines. A literature search was performed to detect studies that have quantified Lp(a) levels in women with PCOS compared to a control group. The primary outcome was Lp(a) levels expressed in mg/dL. Random effects models were used.

RESULTS

Twenty-three observational studies including 2,337 patients were identified and considered eligible for this meta-analysis. In the overall analysis, the quantitative analysis showed that patients with PCOS have a higher Lp(a) levels (SMD: 1.1 [95% CI: 0.7 to 1.4]; I²=93%) compared to the control group. The results were similar in the analysis of the subgroups of patients according to body mass index (normal weight group: SMD: 1.2 [95% CI: 0.5 to 1.9], I²=95%; overweight group: SMD: 1.2 [95% CI: 0.5 to 1.8], I²=89%). Sensitivity analysis showed that the results were robust.

CONCLUSIONS

This meta-analysis shows that women with PCOS had higher levels of Lp(a) compared to healthy women used as a control group. These findings were observed in both overweight and non-overweight women.

The relationship between polycystic ovary syndrome and coronary heart disease: a bibliometric analysis

Background

Polycystic ovary syndrome (PCOS) is one of the most common gynecological endocrine diseases for women of puberty and reproductive age. PCOS can affect women's health for the rest of their lives since the incidence of coronary heart disease (CHD) may increase in the perimenopausal and senile periods among PCOS women compared with non-PCOS women.

Method

A literature retrieval based on the Science Citation Index Expanded (SCI-E) database. All obtained records results were downloaded in plain text format for subsequent analysis. VOSviewer v1.6.10, Citespace and Microsoft Excel 2010 software were utilized for analyzing the following terms: countries, institutions, authors, journals, references and keywords.

Results

There were 312 articles retrieved from January 1, 2000 to February 8, 2023, and the frequency of citations was 23,587. The United States, England, and Italy contributed the majority of the records. Harvard University, the University of Athens, and Monash University were the top 3 most productive institutions with publications on the relationship between PCOS and CHD. Journal of clinical endocrinology & metabolism ranked first with the highest publications (24 records), followed by Fertility and sterility (18 records). The keywords were divided into six clusters in the overlay keywords network: (1) the correlation between CHD risk factors and PCOS women; (2) the relationship between cardiovascular disease and female reproductive system hormone secretion; (3) the interaction between CHD and metabolic syndrome; (4) the relationship between c-reactive protein and endothelial function and oxidative stress in PCOS patients; (5) the potential positive effect of metformin on reducing CHD risk factors in PCOS patients; (6) the study of serum cholesterol and body-fat distribution in patients with CHD in PCOS. Oxidative stress, genome-wide association, obesity, primary prevention, and sex difference were main hotspots in this field in recent five years according to the keyword citation burst analysis.

Conclusion

The article obtained the hotspots and trends and provided a reference for subsequent research on the association between PCOS and CHD. Moreover, it is hypothesized that oxidative stress and genome-wide association were frontier hotspots in studies that explore the relationship between PCOS and CHD, and prevention research may be valued in the future.

Obesity-associated cardiometabolic complications in polycystic ovary syndrome: The potential role of sodium-glucose cotransporter-2 inhibitors

Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive-age women. PCOS is characterized by androgen excess, oligo/anovulation, and polycystic appearance of the ovaries. Women with PCOS have an increased prevalence of multiple cardiovascular risk factors such as insulin resistance, hypertension, renal injury, and obesity. Unfortunately, there is a lack of effective, evidence-based pharmacotherapeutics to target these cardiometabolic complications. Sodium-glucose cotransporter-2 (SGLT2) inhibitors provide cardiovascular protection in patients with and without type 2 diabetes mellitus. Although the exact mechanisms of how SGLT2 inhibitors confer cardiovascular protection remains unclear, numerous mechanistic hypotheses for this protection include modulation of the renin-angiotensin system and/or the sympathetic nervous system and improvement in mitochondrial function. Data from recent clinical trials and basic research show a potential role for SGLT2 inhibitors in treating obesity-associated cardiometabolic complications in PCOS. This narrative review discusses the mechanisms of the beneficial effect of SGLT2 inhibitors in cardiometabolic diseases in PCOS.

A brief insight into the etiology, genetics, and immunology of polycystic ovarian syndrome (PCOS)

Polycystic ovarian syndrome (PCOS) is a prevailing endocrine and metabolic disorder occurring in about 6-20% of females in reproductive age. Most symptoms of PCOS arise early during puberty. Since PCOS involves a combination of signs and symptoms, thus it is considered as a heterogeneous disorderliness. The most accepted diagnostic criteria is Rotterdam criteria which involves two of the latter three features: (a) hyperandrogenism, (b) oligo- or an-ovulation, and (c) polycystic ovaries. The persistent hormonal imbalance leads to multiple small antral follicles formation and irregular menstrual cycle, ultimately causing infertility among females. Insulin resistance, cardiovascular diseases, abdominal obesity, psychological disorders, infertility, and cancer are also related to PCOS. These pathophysiologies associated with PCOS are interrelated with each other. Hyperandrogenism causes insulin resistance and hyperglycemia, leading to ROS formation, oxidative stress, and abdominal adiposity. In consequence, inflammation, ROS production, insulin resistance, and hyperandrogenemia also increase. Elevation of AGEs in the body either produced endogenously or consumed from diet exaggerates PCOS symptoms and is also related to ovarian dysfunction. This review summarizes how AGE formation, inflammation, and oxidative stress are significantly essential in PCOS progression. Alterations during prenatal development like exposure to excess AMH, androgens, or toxins (bisphenol-A, endocrine disruptors, etc.) may also be the etiologic mechanism behind PCOS. Although the etiology of this disorder is unclear, environmental and genetic factors are primarily involved. Physical inactivity, as well as unhealthy eating habits, has a vital role in the progression of PCOS. This review outlines a collection of specific genes phenotypically linked with PCOS. Furthermore, beneficial effect of metformin in maintaining endocrine abnormalities and ovarian function is also mentioned. Kisspeptin is a protein which helps in onset of puberty and increases GnRH pulsatile release during ovulation as well as role of KNDy neurons in GnRH pulsatile signal required for reproduction are also elaborated. This review also focuses on the immunology related to PCOS involving chronic low-grade inflammation, and how the alterations within the follicular microenvironment are intricated in the development of infertility in PCOS patients. How PCOS develops following antiepileptic and psychiatric medication is also expanded in this review. Initiation of antiandrogen treatment in early age (≤ 25 years) might be helpful in spontaneous conception in PCOS women. The role of BMP (bone morphogenetic proteins) in folliculogenesis and their expression in oocytes and granulosa cells are also explained. GDF8 and SERPINE1 expression in PCOS is given in detail.

Comparison of Serum Vitamin B12 Levels Among Drug-Naïve and Metformin-Treated Patients With Polycystic Ovary Syndrome

Background

Metformin is frequently prescribed for polycystic ovary syndrome (PCOS). There is a well-established causal relationship between metformin use in type 2 diabetes and vitamin B12 deficiency; such a relationship is seldom studied in PCOS. We conducted this study to compare vitamin B12 levels among newly diagnosed and metformin-treated patients with PCOS.

Methodology

This cross‑sectional comparative study was conducted from July 2021 to June 2022, among patients with PCOS attending a specialized endocrinology clinic of a tertiary hospital in Mymensingh, Bangladesh. A total of 50 patients newly diagnosed with PCOS and 52 with PCOS who had received metformin for at least six months were evaluated. The serum vitamin B12 level was measured by utilizing the chemiluminescent microparticle immunoassay principle.

Results

The new drug-naïve and metformin-treated subjects with PCOS had similar clinical and laboratory parameters except for the metformin group’s lower hemoglobin levels and higher plateletcrit. Metformin receivers had lower serum vitamin B12 levels than the drug-naïve subjects (385.5 pg/mL [interquartile range, or IQR, 298.7-535.2] vs. 272.0 pg/mL [IQR 217.0-395.7]; P < 0.001). The metformin group had higher frequencies of B12 deficiency and borderline deficiency (15.4% vs. 6% and 42.3% vs. 18%, respectively; P = 0.003).

Conclusions

This study observed lower serum B12 levels in PCOS patients using metformin than in the newly diagnosed ones. Large-scale data are needed to recommend routine periodic screening for B12 levels in metformin-treated PCOS.

Mitochondrial function and oxidative stress in white adipose tissue in a rat model of PCOS: effect of SGLT2 inhibition

Background

Polycystic ovary syndrome (PCOS), characterized by androgen excess and ovulatory dysfunction, is associated with a high prevalence of obesity and insulin resistance (IR) in women. We demonstrated that sodium–glucose cotransporter-2 inhibitor (SGLT2i) administration decreases fat mass without affecting IR in the PCOS model. In male models of IR, administration of SGLT2i decreases oxidative stress and improves mitochondrial function in white adipose tissue (WAT). Therefore, we hypothesized that SGLT2i reduces adiposity via improvement in mitochondrial function and oxidative stress in WAT in PCOS model.

Methods

Four-week-old female rats were treated with dihydrotestosterone for 90 days (PCOS model), and SGLT2i (empagliflozin) was co-administered during the last 3 weeks. Body composition was measured before and after SGLT2i treatment by EchoMRI. Subcutaneous (SAT) and visceral (VAT) WAT were collected for histological and molecular studies at the end of the study.

Results

PCOS model had an increase in food intake, body weight, body mass index, and fat mass/lean mass ratio compared to the control group. SGLT2i lowered fat mass/lean ratio in PCOS. Glucosuria was observed in both groups, but had a larger magnitude in controls. The net glucose balance was similar in both SGLT2i-treated groups. The PCOS SAT had a higher frequency of small adipocytes and a lower frequency of large adipocytes. In SAT of controls, SGLT2i increased frequencies of small and medium adipocytes while decreasing the frequency of large adipocytes, and this effect was blunted in PCOS. In VAT, PCOS had a lower frequency of small adipocytes while SGLT2i increased the frequency of small adipocytes in PCOS. PCOS model had decreased mitochondrial content in SAT and VAT without impacting oxidative stress in WAT or the circulation. SGLT2i did not modify mitochondrial function or oxidative stress in WAT in both treated groups.

Conclusions

Hyperandrogenemia in PCOS causes expansion of WAT, which is associated with decreases in mitochondrial content and function in SAT and VAT. SGLT2i increases the frequency of small adipocytes in VAT only without affecting mitochondrial dysfunction, oxidative stress, or IR in the PCOS model. SGLT2i decreases adiposity independently of adipose mitochondrial and oxidative stress mechanisms in the PCOS model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-022-00455-x.

Androgen excess in PCOS model is associated with decreased markers of mitochondrial content in both subcutaneous and visceral white adipose tissue.

Androgen excess in PCOS model is associated with increased frequency of small adipocytes in subcutaneous white adipose tissue while decreasing frequency of small adipocytes in visceral white adipose tissue.

SGLT2 inhibition did not modify markers of mitochondrial content or oxidative stress in either subcutaneous or visceral white adipose tissue in PCOS model.

SGLT2 inhibition increased frequency of small adipocytes in both subcutaneous and visceral white adipose tissue in control rats; however, SGLT2 inhibition only increased frequency of small adipocytes in visceral white adipose tissue in PCOS model.

The relationship between polycystic ovary syndrome and insulin resistance from 1983 to 2022: A bibliometric analysis

Background

Polycystic ovary syndrome (PCOS) is a common clinical disease often associated with insulin resistance (IR). The interaction between PCOS and IR will promote the progress of PCOS and the risk of related complications, harm women's physical and mental health, and increase the social and economic burden.

Materials and Methods

PCOS IR-related works of literature were retrieved through the Web of Science Core Collection (WoSCC) Database and imported into VOSviewer and CiteSpace, respectively, in plain text format to conduct the literature visualization analysis of authors, countries, institutions, highly cited works of literature, and keywords, aiming to reveal the hot spots and trends of PCOS IR fields.

Results

A total of 7,244 articles were retrieved from 1900 to 2022. Among them, the United States has made the largest contribution. Diamanti-Kandarakis E was the author with the most publications, and the University of Athens was the institution with most publications. Keyword analysis showed that PCOS interacts with IR mainly through sex-hormone binding globulin, luteinizing hormone, insulin-like growth factor, oxidative stress, and other mechanisms. In addition, the complications of PCOS complicated with IR are also the focus of researchers' attention.

Conclusions

Through bibliometric analysis, this paper obtains the research hotspot and trend of PCOS IR fields, which can provide a reference for subsequent research.

Comparative efficacy of oral insulin sensitizers metformin, thiazolidinediones, inositol, and berberine in improving endocrine and metabolic profiles in women with PCOS: a network meta-analysis

Background

Multiple oral insulin-sensitizing agents, such as metformin, thiazolidinediones, inositols, and berberine, have been proven safe and efficacious in improving the endocrine, metabolic, and reproductive abnormalities seen in polycystic ovary syndrome (PCOS), providing more options for healthcare providers and patients. These oral insulin sensitizers are more convenient, practical, and economic than agents that need to be injected. A comparison of the clinical effectiveness of the four different classes of oral insulin sensitizers in PCOS has not been explored, leading to clinical uncertainty about the optimal treatment pathway. The present study aims to compare the effects of oral insulin sensitizers on endocrine and metabolic profiles in women with PCOS.

Methods

We identified randomized controlled trials for PCOS from a variety of databases, published from January 2005 to October 2020. Outcomes included changes in menstrual frequency, improvements in hyperandrogenism and glucolipid metabolism and adverse side effects. A random-effects network meta-analysis was performed.

Results

Twenty-two trials comprising 1079 patients with PCOS were included in this study. Compared with metformin, treatment with myo-inositol + d-chiro-inositol was associated with a greater improvement in menstrual frequency (odds ratio 14.70 [95% confidence interval (CI) 2.31–93.58]). Myo-inositol + d-chiro-inositol and metformin + thiazolidinediones combination therapies were superior to respective monotherapies in reducing total testosterone levels. Thiazolidinediones, metformin + thiazolidinediones, and myo-inositol + d-chiro-inositol were associated with a lower insulin resistance index (HOMA-IR) compared with that in metformin alone (mean differences: − 0.72 [95% CI (− 1.11)–(− 0.34)] to − 0.89 [95% CI (− 1.460)–(− 0.32)]). Metformin + thiazolidinediones treatment was associated with lower triglyceride levels compared with that in metformin and thiazolidinediones monotherapy, while thiazolidinediones was superior to metformin in increasing high-density lipoprotein cholesterol and decreasing fasting plasma glucose, triglycerides, low-density lipoprotein cholesterol, and gastrointestinal adverse events.

Conclusions

Ours is the first study to report that for women with PCOS, myo-inositol combined with d-chiro-inositol and metformin combined with thiazolidinediones appear superior to metformin alone in improving insulin resistance and decreasing total testosterone. Myo-inositol combined with d-chiro-inositol is particularly efficacious in menstrual recovery. Thiazolidinediones and metformin combined with thiazolidinediones improve lipid metabolism better than metformin alone.

Trial registration PROSPERO CRD42020211524

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-021-01207-7.

This study aimed to compare the effects of oral insulin sensitizers on endocrine and metabolic profiles in women with polycystic ovary syndrome (PCOS). A random-effects network meta-analysis including 22 trials was conducted. For women with PCOS, myo-inositol combined with d-chiro-inositol and metformin combined with thiazolidinediones appear superior to metformin alone in improving insulin resistance and decreasing total testosterone level. Myo-inositol combined with d-chiro-inositol is particularly efficacious in menstrual recovery. Thiazolidinediones and metformin combined with thiazolidinediones improve lipid metabolism better than metformin alone.

The effect of metformin on homocysteine levels in patients with polycystic ovary syndrome: A systematic review and meta-analysis

PURPOSE

Metformin is widely used as an insulin sensitizer in polycystic ovary syndrome (PCOS) patients. However, previous studies have found that the effect of metformin on the level of homocysteine were not consistent in PCOS patients. The aim of this review was to analyze the effect of metformin on homocysteine levels in patients with PCOS patients.

METHODS

The Cochrane Library, Pubmed, and Web of Science were searched according to predefined search terms. There is no restriction for publication time and language.

RESULTS

Eleven studies were included and the data were extracted. The homocysteine level in PCOS patients was significantly increased after taking metformin (mean difference [MD] -1.33; 95% confidence interval [CI] -2.16 to -0.49, p = 0.002). Subgroup analysis showed that the level of homocysteine was generally increased in PCOS patients with body mass index (BMI) ≥25 after taking metformin alone (MD -1.82; 95% CI -2.56 to -1.07, p < 0.00001). There was no significant change in homocysteine level in PCOS patients with BMI <25 (MD 0.69; 95% CI -0.41 to 1.79, p = 0.22). Subgroup analysis showed that there was no significant difference when taking metformin >3 months or taking metformin ≤3 months (p = 0.84). Taking metformin ≥1700 mg/days significantly increased homocysteine levels in PCOS patients (MD -2.05; 95% CI -2.40 to -1.70, p < 0.00001). When taking metformin <1700 mg/days, there was no significant difference in homocysteine level in PCOS patients (MD 0.15; 95% CI -1.06 to 1.37, p = 0.80). The difference between the two subgroups was significant (p = 0.0006). There was no significant difference in vitamin B12 level before and after metformin treatment (MD 24.70; 95% CI -22.54 to 71.93, p = 0.31). There was a decrease in serum folic acid level after metformin administration (MD 1.03; 95% CI 0.80 to 1.26, p < 0.00001).

CONCLUSION

Taking metformin alone increased homocysteine levels and decreased folic acid levels in nonpregnant PCOS patients. And, it was suggested that the dosage of metformin should be less than 1700 mg/days. The supplement of folic acid and B vitamins during metformin administration may be essential in nonpregnant PCOS patients. We should pay much attention to the potential effect of metformin in PCOS patients.

Prenatal testosterone exposure induces insulin resistance, uterine oxidative stress and pro-inflammatory status in rats

Prenatal androgen excess is considered one of the main causes of the development of polycystic ovary syndrome. In this study, we investigated the effect of prenatal hyperandrogenization (PH) on the physiology of the adult uterine tissue using a murine model of fetal programming caused by androgen excess in adult female rats. Pregnant rats were hyperandrogenized with testosterone and female offspring were studied when adult. Our results showed that PH leads to hyperglycemia and hyperinsulinemia. Consequently, PH developed insulin resistance and a systemic inflammatory state reflected by increased C-reactive protein. In the uterine tissue, levels of PPAR gamma-an important metabolic sensor in the endometrium-were found to be impaired. Moreover, PH induced a pro-inflammatory and an unbalanced oxidative state in the uterus reflected by increased COX-2, lipid peroxidation, and NF-κB. In summary, our results revealed that PH leads to a compromised metabolic state likely consequence of fetal reprogramming.

Effect of rosiglitazone on circulating malondialdehyde (MDA) level in diabetes based on a systematic review and meta-analysis of eight clinical trials

Patients with type 2 diabetes have high levels of malondialdehyde (MDA), and clinical data suggest a reducing effect of rosiglitazone (RSG) on the level of MDA in these patients. However, the results of available studies on the level of MDA in RSG-treated patients are not univocal. This meta-analysis aimed to assess the impact of RSG on the level of MDA. We performed a comprehensive search of PubMed, the Institute for Scientific Information Web of Science, Embase, Scopus, and Cochrane Library for related controlled trials until July 2020. Eligible studies were selected based on the inclusion criteria. Extracted data from each study were combined using a random-effects model. Sensitivity and subgroup analyses were conducted to explore potential heterogeneity. Eight trials with 456 subjects met the inclusion criteria. The results significantly showed the reducing effect of RSG on circulating MDA level (−0.47 μmol/mL; 95% CI −0.93 to −0.01; p=0.04; I2=82.1%; p heterogeneity=0.00) in individuals with T2D. No publication bias was observed with Begg’s rank correlation (p=0.71) and Egger’s linear regression (p=0.52) tests. Subgroup analyses showed that an intervention dose of 8 mg/day in serum samples was found to have a reducing effect on the level of MDA (−0.56 μmol/mL; 95% CI −0.98 to −0.14; p=0.008; I2=11.4%; p heterogeneity=0.32). Random-effects meta-regression did not show any significant association between the level of MDA and potential confounders including RSG dose, treatment duration, and sex. In conclusion, we found a significant reduction in MDA concentration in subjects with T2D who received a dose of 8 mg of RSG daily.

Significance of Homocysteine Levels in the Management of Polycystic Ovarian Syndrome: A Literature Review

Polycystic ovarian syndrome (PCOS) is a complex disorder involving cardiovascular, metabolic, endocrine, and reproductive systems. Even though the exact etiology is not clear, many studies suggest genetic and environmental factors play a role. Homocysteine (Hcy) is considered to be an independent risk factor for atherogenic and thrombotic components of various systems. Many studies in the past have evaluated Hcy levels in the PCOS population. This article aims to elaborate on the importance of Hcy levels in the overall management of PCOS. We conducted a PubMed data search using combined keywords PCOS and homocysteine levels and manually screened relevant articles for the review while avoiding duplication of data. After the literature review, we analyzed the relationship between homocysteine levels and various components of PCOS. Most of the studies identified a statistically significant elevation in Hcy levels in PCOS women with insulin resistance, androgen excess, elevated markers of cardiovascular risk, recurrent pregnancy loss, and metformin treatment. We also examined studies that focused on treating hyperhomocysteinemia (Hhcy) in PCOS women. However, because of the limited sample sizes and various inclusion criteria used for subjects in the studies, their clinical implication is unclear in routine practice. Furthermore, we encourage clinicians to follow up on Hcy levels in PCOS women at high risk for any complications in their management course. We believe an observational study on a larger scale in a well-defined PCOS population would be useful to uncover the prevalence of elevated Hcy levels in PCOS women, which would help pave the way for establishing treatment guidelines on serum Hcy levels in PCOS management.

Assessing the effect of MitoQ10 and Vitamin D3 on ovarian oxidative stress, steroidogenesis and histomorphology in DHEA induced PCOS mouse model

Polycystic ovary syndrome (PCOS) continues to be one of the most complex reproductive and endocrine disorder among women of reproductive age. Recent reports have identified close interaction of Vitamin D deficiency and oxidative stress (OS) in exacerbating the pathophysiology of PCOS. This current study aims at assessing the combine effect of MitoQ₁₀ and Vitamin D3 on dehydroepiandrosterone (DHEA) induced PCOS. Following successful induction of PCOS using DHEA, mice were organized into five groups (n = 8) namely: Negative Control (NC), Vitamin D3 Vehicle (VDV), Vitamin D3 (VD), MitoQ₁₀ (MQ), Vitamin D3 plus MitoQ₁₀ (V+M) and DHEA, ethanol and distilled water, Vitamin D3, MitoQ₁₀ and Vitamin D3 plus MitoQ₁₀ were respectively administered for 20 consecutive days. The study also included positive control (PC) group (n = 8) in which no treatment was applied. Treatment effects were assessed using hormonal assays, biochemical assays, Real-Time PCR, western blotting and histological analysis. Combination of Vitamin D3 and MitoQ₁₀ significantly reduced levels of estradiol, progesterone, FSH, LH, LH/FSH, SOD and MDA. The expression rate of mRNAs of 3β-HSD, Cyp19a1, Cyp11a1, StAR, Keap1, HO-1 and Nrf2 were also significantly low in V+M group. Moreover, the histomorphological inspection of ovaries from this group revealed many healthy follicles at various stages of development including few atretic follicles, pre-antral and antral follicles and many corpora lutea. The characteristics observed in this group were in many ways similar to that of the PC group. The combination of MitoQ₁₀ and Vitamin D3 may be potential candidate to ameliorate PCOS.

Five variants of the superoxide dismutase genes in Turkish women with polycystic ovary syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is one of the most common endocrine-reproductive-metabolic disorders of women at reproductive age. Many investigations have revealed that reactive oxygen species (ROS) level is significantly increased in patients with PCOS compared to healthy women.

OBJECT

The goal of the current study is to investigate the association between superoxide dismutase (SOD) variants and the risk of PCOS among Turkish women.

METHOD AND SUBJECTS

Three hundred twelve voluntary premenopausal women (148 healthy controls and 164 patients with PCOS) 18-45 years of age were include the study. All volunteers underwent physical examination and biochemical hormones evaluation. Five selected variants in SOD1 (+35 A/C (rs2234694) and SOD2 (-102 C > T, 3'UTRT > A (rs2842980), 3'UTRA > G (rs5746136), and Ala16ValC > T (rs4880) were analysed by using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method.

RESULT

3'UTRA > G and Ala16ValC > T variants showed significant differences between study groups. In the additive model of rs5746136 variant having AG and GG genotype increased the PCOS risk 2-fold (OR: 1.7, 95% CI: 1.08-2.77, p = 0.003) and 5-fold (OR: 5, 95% CI: 1.7-14.2,p = 0.003) compared to AA genotype, respectively. To have a GG + AG genotype increased the PCOS risk 2-fold (OR: 2.95% Cl: 1.2-3.1, p = 0.003) compared to AA genotype in "G" dominant model. In case of the "G" recessive model, having a GG genotype increased the PCOS risk 4-fold (OR: 3.8, 95% CI: 1.3-10.4, p = 0.01) compared to AA + AG genotype. The TT genotype of rs4880 showed almost 2-fold (OR: 1.8, 95% CI: 1.12-3.0) increased PCOS risk in the "T" recessive model.

CONCLUSION

It is quite likely that the variants which result in decreased function in the antioxidant defence mechanism related genes contribute to PCOS aetiology with inhibiting/reducing of ROS elimination.

Polycystic ovary syndrome and endothelial dysfunction: A potential role for soluble lectin-like oxidized low density lipoprotein receptor-1

The aims of this study were to investigate whether serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1), oxidized LDL (oxLDL), paraoxonase-1(PON-1) and hydroperoxide (LOOH) levels are altered in women with polycystic ovary syndrome (PCOS) and also to determine if hyperandrogenism, insulin resistance (IR) and Anti-Müllerian Hormone (AMH) are associated with endothelial dysfunction in PCOS. A total of 46 women with PCOS and 46 non-PCOS healthy controls were recruited. Women with PCOS had significantly higher sLOX-1, oxLDL and LOOH concentrations than non-PCOS women [6.16 (3.92-13.95) vs 1.37 (0.63-4.43) ng/mL, p < 0.001; 6.48 ± 1.03 vs 3.16 ± 1.02 μU/L, p < 0.001; 2.45 (1.45-3.45) vs 1.06 (0.64-1.56) μmol/L, p < 0.001]. The mean PON-1 level of PCOS group was lower than non-PCOS group (69.47 ± 10.75 vs 104.08 ± 21.43 U/mL, p < 0.001). There was no significant difference in terms of the sLOX-1, oxLDL, LOOH and PON-1 levels between normal weight and overweight PCOS women. On univariate logistic regression analysis, Ferriman-Gallwey scale (FGS), HOMA-IR and AMH were an independent predictors of high risk group of endothelial dysfunction markers (HR-EDm). Age and BMI were not associated with HR-EDm. When incorporated into the multivariate model, endotelial dysfunction markers independently correlated with clinical hyperandrogenism (FGS) but not with AMH. In conclusion, our results indicated that an increased concentration of sLOX-1 might be an early predictor of endothelial damage in patients with PCOS. Women with PCOS have elevated sLOX-1, oxLDL, LOOH and decreased PON-1 levels, independent of BMI. Endothelial dysfunction in women with PCOS is associated with hyperandrogenism. Further studies are required to confirm our findings.

Comparison of the efficacy between NAC and metformin in treating PCOS patients: a meta-analysis

Our aim is to evaluate the clinical effectiveness and safety by comparing N-acetyl-cysteine (NAC) with metformin administrated by polycystic ovary syndrome (PCOS) patients. Systematic review and meta-analysis of randomized clinical trials (RCTs). MEDLINE, EMBASE, Web of Science and China National Knowledge Infrastructure were searched for studies. 10 studies were considered eligible for inclusion. NAC significantly reduced BMI and total testosterone, there was no significant difference in pregnancy rate, serum LH level, fasting insulin, and LH/FSH ratio. In conclusions, NAC may be considered as an alternative supplement to metformin, but large-scale randomized controlled trials are needed to assess the efficacy and safety of NAC in PCOS patients.

The protective and therapeutic effects of vinpocetine, a PDE1 inhibitor, on oxidative stress and learning and memory impairment induced by an intracerebroventricular (ICV) injection of amyloid beta (aβ) peptide

Alzheimer's disease (AD) is a neurodegenerative disease leading to cognitive and memory impairment. This study aimed at investigating the therapeutic and preserving effects of vinpocetine on amyloid beta (Aβ)-induced rat model of AD. Sixty male adult Wistar rats were randomly divided into 6 groups (n = 10 per group) as follows: 1; control, 2; sham, 3; Aβ, 4; pre-treatment (vinpocetine + Aβ): oral gavage administration of vinpocetine at 4 mg/kg for 30 days followed by intracerebroventricular (ICV) injection of Aβ, 5; treatment (Aβ + vinpocetine): Aβ ICV injection followed by vinpocetine administration for 30 days, 6; pre-treatment + treatment (vinpocetine + Aβ + vinpocetine): vinpocetine administration for 30 days before and 30 days after AD induction. Following treatments, the animals' learning and memory were investigated using passive avoidance learning (PAL) task, Morris water maze (MWM), and novel object recognition (NOR) tests. The results demonstrated that Aβ significantly enhanced escape latency and the distance traveled in the MWM, decreased step-through latency, and increased time spent in the dark compartment in PAL. Vinpocetine ameliorated the Aβ-infused memory deficits in both MWM and PAL tests. Administration of vinpocetine in the Aβ rats increased the discrimination index of the NOR test. It also significantly diminished the nitric oxide and malondialdehyde levels and restored the reduced glutathione (GSH) levels. Vinpocetine can improve memory and learning impairment following Aβ infusion due to its different properties, including antioxidant effects, which indicates that vinpocetine administration can lead to the amelioration of cognitive dysfunction in AD.

Implicating androgen excess in propagating metabolic disease in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) has been traditionally perceived as a reproductive disorder due to its most common presentation with menstrual dysfunction and infertility. However, it is now clear that women with PCOS are at increased risk of metabolic dysfunction, from impaired glucose tolerance and type 2 diabetes mellitus to nonalcoholic fatty liver disease and cardiovascular disease. PCOS is characterised by androgen excess, with cross-sectional data showing that hyperandrogenism is directly complicit in the development of metabolic complications. Recent studies have also shown that C11-oxy _C19 androgens are emerging to be clinically and biochemically significant in PCOS, thus emphasising the importance of understanding the impact of both classic and C11-oxy _C19 androgens on women's health. Here we discuss androgen metabolism in the context of PCOS, and dissect the role played by androgens in the development of metabolic disease through their effects on metabolic target tissues in women.

Evaluation of oxidative status in patients with chronic periodontitis and polycystic ovary syndrome: A cross-sectional study

BACKGROUND

In patients with polycystic ovary syndrome (PCOS), chronic periodontitis (CP) contributed to increased oxidative stress (OS), owing to an increase in serum and salivary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) levels and a decrease in serum total antioxidant status (TAS) levels. The aim of the present study is to investigate salivary and serum 8-OHdG and MDA levels as well as total antioxidant status (TAS) in females with CP and PCOS compared with healthy females.

METHODS

Four groups, each consisting of 22 individuals, were: 1) women with both PCOS and CP (PCOSCP); 2) systemically healthy women with CP; 3) periodontally healthy women with PCOS (PCOSPH); and 4) periodontally and systemically healthy women (PH). Demographic and clinical periodontal parameters were measured. Oxidative parameters were evaluated in serum and salivary samples.

RESULTS

Salivary 8-OHdG levels in the PCOSCP and CP groups were statistically higher than those in both the PCOSPH and the PH groups (P < 0.05). There was no statistical difference between the PCOSCP, CP, and PCOSPH groups with regard to salivary MDA and TAS levels (P > 0.05). Highest serum 8-OHdG and MDA levels and lowest serum TAS levels were seen in the PCOSCP group (P < 0.05). Serum 8-OHdG and MDA levels in the PCOSPH group were higher than those in both systemically healthy groups (PH and CP) (P < 0.05). Salivary TAS levels were highest (P < 0.05) in the PH group. There was no statistical difference between the CP and PCOSPH groups, but serum TAS levels were lower than those in the PH group (P < 0.05).

CONCLUSIONS

CP, which led to an increase in serum and salivary 8-OHdG and MDA levels and a decrease in serum TAS levels in patients with PCOS, contributed to increased OS. This effect was more prominent in serum levels than in salivary levels.

Genistein protects ovarian granulosa cells from oxidative stress via cAMP-PKA signaling

Genistein is an isoflavone that has estrogen (E₂ )-like activity and is beneficial for follicular development, but little is known regarding its function in oxidative stress (OS)-mediated granulosa cell (GC) injury. Here, we found that after exposure to H₂ O₂ , Genistein weakened the elevated levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), which were regarded as the biomarkers for OS, and rescued glutathione (GSH) content and GSH/GSSG ratio accompanying with a simultaneous increase in cyclic adenosine monophosphate (cAMP) level, whereas addition of protein kinase A (PKA) inhibitor H89 impeded the effects of Genistein on the levels of ROS and MDA. Further analysis evidenced that Genistein enhanced the activities of antioxidant enzymes superoxide dismutase (SOD), GSH-peroxidase (GSH-Px), and catalase (CAT) in H₂ O₂ -treated GCs, but this enhancement was attenuated by H89. Under OS, Genistein improved cell viability and lessened the apoptotic rate of GCs along with a reduction in the activity of Casp3 and levels of Bax and Bad messenger RNA (mRNA), while H89 reversed the above effects. Moreover, Genistein treatment caused an obvious elevation in mitochondrial membrane potential (MMP) followed by a decline in the levels of intracellular mitochondrial superoxide, but H89 inhibited the regulation of Genistein on MMP and mitochondrial superoxide. Supplementation of Genistein promoted the secretion of E₂ and increased the expression of Star and Cyp19a1 mRNA, whereas suppressed the level of progesterone (P₄ ) accompanied with a decline in the level of Hsd3b1 mRNA expression. H89 blocked the regulation of Genistein on the secretion of E₂ and P₄ , and alleviated the ascending of Star and Cyp19a1 elicited by Genistein. Collectively, Genistein protects GCs from OS via cAMP-PKA signaling.

Nitric oxide (NO) levels in patients with polycystic ovary syndrome (PCOS): a meta-analysis

Objective

The pathogenesis of polycystic ovarian syndrome (PCOS) remains unclear, but is known to be related to increased insulin resistance, diabetes, obesity, oxidative stress, inflammation, and cardiovascular disease. No meta-analyses have examined whether PCOS is associated with nitric oxide (NO). Therefore, we aimed to evaluate the association between serum/plasma nitrite levels and PCOS.

Methods

We performed a meta-analysis. To identify eligible original articles, we searched online computerized databases, including EMBASE, Medline, and Web of Science. The characteristics of each single study, as well as the standard mean difference (SMD) with corresponding confidence intervals (CIs), were calculated and subgroup analysis was performed to examine heterogeneity.

Results

We included 12 articles with 16 studies and a total of 895 patients were included in the meta-analysis. We found a significant association between PCOS and serum or plasma nitrite levels, with a pooled SMD of −0.61 (95% CI: −1.05 to −0.16). The final pooled data were determined by the random effects model because significant high heterogeneity (I² = 89%) was found.

Conclusions

Our meta-analysis shows that decreased serum or plasma nitrite levels are associated with PCOS. The pathogenesis of PCOS may be due to endothelial dysfunction; however, further research to confirm this possibility is required.

Polycystic ovary syndrome and mitochondrial dysfunction

Polycystic ovary syndrome (PCOS) is a prevalent hormonal disorder of premenopausal women worldwide and is characterized by reproductive, endocrine, and metabolic abnormalities. The clinical manifestations of PCOS include oligomenorrhea or amenorrhea, hyperandrogenism, ovarian polycystic changes, and infertility. Women with PCOS are at an increased risk of suffering from type 2 diabetes; me\tabolic syndrome; cardiovascular events, such as hypertension, dyslipidemia; gynecological diseases, including infertility, endometrial dysplasia, endometrial cancer, and ovarian malignant tumors; pregnancy complications, such as premature birth, low birthweight, and eclampsia; and emotional and mental disorders in the future. Although numerous studies have focused on PCOS, the underlying pathophysiological mechanisms of this disease remain unclear. Mitochondria play a key role in energy production, and mitochondrial dysfunction at the cellular level can affect systemic metabolic balance. The recent wide acceptance of functional mitochondrial disorders as a correlated factor of numerous diseases has led to the presupposition that abnormal mitochondrial metabolic markers are associated with PCOS. Studies conducted in the past few years have confirmed that increased oxidative stress is associated with the progression and related complications of PCOS and have proven the relationship between other mitochondrial dysfunctions and PCOS. Thus, this review aims to summarize and discuss previous and recent findings concerning the relationship between mitochondrial dysfunction and PCOS.

Metformin attenuates oxidative stress and liver damage after bile duct ligation in rats

The aim of the current study was to investigate the antioxidative effect of metformin (MTF) on bile duct ligation (BDL)-induced hepatic disorder and histological damage in rats. The rats were divided into 4 groups including sham control (SC), BDL alone (BDL surgery), MTF1 (BDL surgery and administration of 250 mg/kg of MFM) and MTF2 (BDL surgery and administration of 500 mg/kg of MTF). After BDL, the animals treated with MTF by gavage for 10 days. Hematoxylin and eosin staining, biochemical analysis and oxidative stress markers were assayed to determine histological alterations, liver functions, and oxidant/antioxidant status. Hepatotoxicity was verified by remarkable increase in plasma levels of aminotransferases and alkaline phosphatase activity and liver histology 10 days after the BDL surgery. Our finding showed that treatment with MTF markedly reduced plasma alkaline phosphatase and alleviated liver injury indices (P ≤ 0.05). Furthermore, BDL caused a considerable increase in the protein carbonyl and malondialdehyde content (P ≤ 0.05). However, MTF reduces oxidative stress by constraining the protein oxidation and lipid peroxidation, and increases antioxidant reserve by increasing the ferric reducing ability of plasma and reducing glutathione levels. MTF exerts antioxidative effects in the liver fibrosis and may represent a hepato-protective effect when given to rats with BDL-induced hepatic injury.

Role of metformin in oxaliplatin-induced peripheral neuropathy in patients with stage III colorectal cancer: randomized, controlled study

PURPOSE

Peripheral sensory neuropathy is the most prominently reported adverse effect of oxaliplatin. The purpose of this study was to evaluate metformin role in oxaliplatin-induced neuropathy.

PATIENTS AND METHODS

From November 2014 to May 2016, 40 patients with stage III colorectal cancer completed 12 cycles of FOLFOX-4 regimen. Twenty patients in the control arm received FOLFOX-4 regimen only, and 20 patients in the metformin arm, received the same regimen along with metformin 500 mg three times daily. The metformin efficacy was evaluated using National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE version 4.0), a12-item neurotoxicity questionnaire (Ntx-12) from the validated Functional Assessment of Cancer Therapy/Gynecologic Oncology Group and, the brief pain inventory short form "worst pain" item. In addition to neurotensin, malondialdehyde and interleukin-6 serum levels assessment.

RESULTS

At the end of the 12th cycle, there were less patients with grade 2 and 3 neuropathy in metformin arm as compared to control arm. (60 versus 95%, P = 0.009) In addition, metformin arm showed significantly higher total scores of Ntx-12 questionnaire than control arm (24.0 versus 19.2, P < 0.001). Furthermore, the mean pain score in metformin arm was significantly lower than those of control arm, (6.7 versus 7.3, P = 0.005). Mean serum levels of malondialdehyde and neurotensin were significantly lower in metformin arm after the 6th and the 12th cycles.

CONCLUSION

Metformin may be a promising drug in protecting colorectal cancer patients against oxaliplatin-induced chronic peripheral sensory neuropathy.

Effect of metformin combined with lifestyle modification versus lifestyle modification alone on proinflammatory-oxidative status in drug-naïve pre-diabetic and diabetic patients: A randomized controlled study

BACKGROUND

Targeting biomarkers of oxidative-proinflammatory stress may result in improvement of modifiable metabolic syndrome, pre-diabetes and diabetes risk factors and subsequent risk reduction.

METHODS

64 newly diagnosed antihyperglycemic treatment-naïve prediabetic and type 2 diabetes mellitus (T2DM) patients were randomly assigned using block design to either metformin combined with therapeutic lifestyle changes (TLC) or TLC alone. Body mass index (BMI), waist circumference, blood pressure, fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), fasting lipid profile, plasma oxidative status and tumor necrosis factor (TNF)-α were measured at baseline, after 3 months and after 6 months from baseline.

RESULTS

Except for HbA1c, baseline values did not differ significantly between the two groups. The post 3-months relative reductions in BMI (P=0.014) and HbA1c (P=0.037) in metformin combined with TLC intervention were significantly greater than those in TLC alone group. TNFα plasma levels were decreased significantly vs. baseline by metformin combined with TLC intervention (-22.90±46.76%, P=0.01). Conversely, TLC alone basically worsened proinflammatory status (42.40±40.82 %), P<0.001. Metformin with TLC treatment effected a therapeutic decrement of the oxidative stress (-15.44±35.32%, P=0.029 vs. baseline) unlike TLC alone (61.49±122.66%, P=0.01 vs. baseline). Both interventions' effects were sustained in the 6-month follow up periods.

CONCLUSION

In both intervention groups, the relative changes in plasma TNFα were significantly correlated (P<0.01) with systolic blood pressure and the relative changes in oxidative stress were markedly correlated (P<0.05) with total cholesterol.

Effects of dietary supplementation of pioglitazone or walnut meal on metabolic profiles and oxidative status in dairy cows with high pre-calving BCS

This research paper addresses the hypothesis that dietary pioglitazone (PGT), as synthetic and specific ligand for PPAR-γ or walnut meal (WM) as a natural ligand for PPAR-γ, affect plasma metabolites and reduce the oxidative status in high body condition score (BCS) dairy cows (≥4 BCS). Total of 36 multiparous Holstein cows were randomly assigned to one of the dietary treatments: 1- Control (basal diet; CTR), 2- Walnut meal (9·45% walnut meal of DMI; WM), and 3- Pioglitazone (6 mg/kg BW; PGT). The experimental diets were fed from parturition time to 21 d postpartum. Results showed that the PGT supplementation increased dry matter intake (DMI) (22·95 kg/d) compared to the CTR (21·45 kg/d) and WM (21·78 kg/d) groups. Results showed that milk yield and milk composition were not affected by the experimental diets. Body condition score losses tended to be higher in the CTR group compared to the PGT and WM cows. The PGT group had higher plasma insulin compared to the CTR group (11·84 vs. 10·68 mIU/l), and WM cows had intermediate plasma insulin. The PGT cows had lower plasma non esterified fatty acid (NEFA) and tended to have lower β-hydroxy butyric acid (BHBA) than the CTR group. Feeding pioglitazone decreased plasma malondialdehyde (MDA) and increased plasma total antioxidant capacity (TAC) and superoxide dismutase (SOD) compared to the CTR and WM groups. It was concluded that dietary pioglitazone had positive effects on DMI, BCS change, blood metabolites and oxidative status in fresh dairy cows with high pre-calving BCS. The anti-oxidant effects of walnut meal were not supported by the present data.

Effects of thymol on amyloid-β-induced impairments in hippocampal synaptic plasticity in rats fed a high-fat diet

Obesity and a high-fat diet (HFD) are known to increase the incidence of Alzheimer's disease (AD). Oxidative stress, a major risk factor for AD, is increased with HFD consumption. Thymol (Thy) has antioxidant properties. Therefore, in the present study, we examined the protective and therapeutic effects of Thy on amyloid-β (Aβ)-induced impairments in the hippocampal synaptic plasticity of HFD-fed rats. In this study, 72 adult male Wistar rats were randomly assigned to 9 groups (n = 8 rats/group): Group 1 (control; standard diet); Group 2: Control + phosphate-buffered saline (PBS) + Oil (Thy vehicle); Group 3 (HFD + PBS); Group 4: (HFD + Aβ); Group 5: Control + PBS + Thy; Group 6: (HFD + Aβ + Oil); Group 7: Control + Aβ + Thy; Group 8: HFD + PBS + Thy; Group 9: (HFD + Aβ + Thy). After stereotaxic surgery, the field potentials were recorded after the implantation of the recording and stimulating electrodes in the dentate gyrus (DG) and perforant pathway, respectively. Following high-frequency stimulation, the long-term potentiation (LTP) of the population spike (PS) amplitude and the slope of the excitatory postsynaptic potentials (EPSPs) were measured in the DG. The HFD rats that received Aβ exhibited a significant decrease in their EPSP slope and PS amplitude as compared to the control group. In contrast, Thy administration in the HFD + Aβ rats reduced the decrease in the EPSP slope and PS amplitude. Thy decreased the Aβ-induced LTP impairments in HFD rats. The HFD significantly increased serum malondialdehyde levels and decreased total antioxidant capacity and total glutathione levels; whereas, Thy supplementation significantly reversed these parameters. Therefore, these results suggest that Thy, a natural antioxidant, can be therapeutic against high risk factors for AD, such as HFD.

Influence of Plantago ovata husk (dietary fiber) on the bioavailability and other pharmacokinetic parameters of metformin in diabetic rabbits

Background

Metformin is an oral hypoglycemic agent frequently used in patients with type 2 diabetes. In this study, we have investigated the influence of the dietary fiber Plantago ovata husk on the pharmacokinetics of this drug when included in the diet, as well as when administered at the same time as metformin.

Methods

Six groups of 6 rabbits were used. Groups 1 to 3 were fed with standard chow and groups 4 to 6 with chow supplemented with fiber (3.5 mg/kg/day). Groups 1 and 4 received metformin intravenously (30 mg/kg). Groups 2 and 5 received metfomin orally (30 mg/kg), and number 3 and 6 were treated orally with metformin (30 mg/kg) and fiber (300 mg/kg).

Results

The changes caused by the inclusion of fiber in the feeding were more important in groups that received oral metformin. In this way, metformin oral bioavailability showed an increase of 34.42% when rabbits were fed with supplemented chow.

Conclusions

Plantago ovata husk increased the amount of absorbed metformin when included in the diet (significant increase in AUC), and delayed its absorption when administered at the same time (significant increase in t_max).

Investigation of thymol effect on learning and memory impairment induced by intrahippocampal injection of amyloid beta peptide in high fat diet- fed rats

Obesity and consumption of a high fat diet (HFD) are known to increase the risk of Alzheimer's disease (AD). In the present study, we have examined the protective and therapeutic effects of thymol (main monoterpene phenol found in thyme essential oil) on a HFD-fed rat model of AD. Fourty adult male Wistar rats were randomly assigned to 5 groups:(n = 8 rats/group): group 1, control, consumed an ordinary diet, group 2 consumed a HFD for 8 weeks, then received phosphate-buffered saline (PBS) via intrahippocampal (IHP) injection, group 3 consumed HFD for 8 weeks, then received beta-amyloid (Aβ)1-42 via IHP injections to induce AD, group 4 consumed HFD for 8 weeks, then received Aβ1-42, and was treated by thymol (30 mg/kg in sunflower oil) daily for 4 weeks, and group 5 consumed HFD for 8 week, then received Aβ1-42 after what sunflower oil was administered by oral gavage daily for 4 weeks. Biochemical tests showed an impaired lipid profile and higher glucose levels upon consumption of HFD, which was ameliorated by thymol treatment. In behavioral results, spatial memory in group 3 was significantly impaired, but groups treated with thymol showed better spatial memory compared to group 3 (p ≤ 0.01). In histological results, formation of Aβ plaque in hippocampus of group 3 increased significantly compared to group 1 and group 2 (p ≤ 0.05), but group 4 showed decreased Aβ plaques compared to group 3 (p ≤ 0.01). In conclusion, thymol decreased the effects of Aβ on memory and could be considered as neuroprotective.

Antioxidant properties of drugs used in Type 2 diabetes management: could they contribute to, confound or conceal effects of antioxidant therapy?

Objectives: This is a narrative review, investigating the antioxidant properties of drugs used in the management of diabetes, and discusses whether these antioxidant effects contribute to, confound, or conceal the effects of antioxidant therapy.

Methods: A systematic search for articles reporting trials, or observational studies on the antioxidant effect of drugs used in the treatment of diabetes in humans or animals was performed using Web of Science, PubMed, and Ovid. Data were extracted, including data on a number of subjects, type of treatment (and duration) received, and primary and secondary outcomes. The primary outcomes were reporting on changes in biomarkers of antioxidants concentrations and secondary outcomes were reporting on changes in biomarkers of oxidative stress.

Results: Diabetes Mellitus is a disease characterized by increased oxidative stress. It is often accompanied by a spectrum of other metabolic disturbances, including elevated plasma lipids, elevated uric acid, hypertension, endothelial dysfunction, and central obesity. This review shows evidence that some of the drugs in diabetes management have both in vivo and in vitro antioxidant properties through mechanisms such as scavenging free radicals and upregulating antioxidant gene expression.

Conclusion: Pharmaceutical agents used in the treatment of type 2 diabetes has been shown to exert an antioxidant effect..

The Effect of Metformin Treatment on the Serum Levels of Homocysteine, Folic Acid, and Vitamin B12 in Patients with Polycystic Ovary Syndrome

Background and Objective:

Hyperhomocysteinemia is a well-known risk factor for cardiovascular disease. Although metformin therapy can increase homocysteine (Hcy) levels, it frequently is used as an oral medicine in women with polycystic ovary syndrome (PCOS), who might be at risk of catching diabetes mellitus. The aim of this study was to investigate the effect of metformin on the levels of serum Hcy, vitamin B12 (vit B12), and folic acid in patients with PCOS.

Materials and Methods:

An interventional study was designed with 18 patients with PCOS at the Fatemehzahra infertility Hospital in Babol, Iran. Metformin treatment (500 mg twice daily) was initiated in all patients for a period of consecutive 6 months. The levels of serum Hcy, vit B12, and folic acid were measured in the participants before and after metformin treatment.

Results:

The mean vit B12 level showed a significant decrease in patients after 6 months of metformin treatment (P = 0.002). However, there was no significant difference in serum folic acid levels. The mean Hcy levels increased after treatment, but this difference not was statistically significant. When patients were stratified into four subgroups by their insulin sensitivity and body mass index (BMI), relatively similar results were obtained in the subgroups, except that Hcy levels in the overweight/obesity group (BMI > 25 kg/m²) after treatment showed a significant increase (P = 0.01).

Conclusion:

These findings indicate that metformin increases the serum Hcy concentration in patients with PCOS especially in the women with BMI > 25 kg/m². The possible mechanism for this effect would be the obvious reduction in the levels of vit B12.

Intracytoplasmic oxidative stress reverses epigenetic modifications in polycystic ovary syndrome

In polycystic ovary syndrome (PCOS), substantial genetic and environmental alterations, along with hyperandrogenism, affect the quality of oocytes and decrease ovulation rates. To determine the mechanisms underlying these alterations caused specifically by an increase in plasma androgens, the present study was performed in experimentally-induced PCOS mice. As the study model, female B6D2F1 mice were treated with dehydroepiandrosterone (DHEA, 6 mg per 100 g bodyweight). After 20 days, oocytes at the germinal vesicle and metaphase II stages were retrieved from isolated ovaries and subsequent analyses of oocyte quality were performed for each mouse. DHEA treatment resulted in excessive abnormal morphology and decreased polar body extrusion rates in oocytes, and was associated with an increase in oxidative stress. Analysis of fluorescence intensity revealed a significant reduction of DNA methylation and dimethylation of histone H3 at lysine 9 (H3K9) in DHEA-treated oocytes, which was associated with increased acetylation of H4K12. Similarly, mRNA expression of DNA methyltransferase-1 and histone deacetylase-1 was significantly decreased in DHEA-treated mice. There was a significant correlation between excessive reactive oxygen species (ROS) production and increased histone acetylation, which is a novel finding and may provide new insights into the mechanism causing PCOS. The results of the present study indicate that epigenetic modifications of oocytes possibly affect the quality of maturation and ovulation rates in PCOS, and that the likely mechanism may be augmentation of intracytoplasmic ROS.

Debates Regarding Lean Patients with Polycystic Ovary Syndrome: A Narrative Review

Polycystic ovary syndrome (PCOS) is a complex syndrome showing the clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Two phenotypes are present, either lean or obese, with different biochemical, hormonal, and metabolic profiles. Evidence suggests many treatment modalities that can be applied. However, many of these modalities were found to be not suitable for the lean phenotype of PCOS. Much contradictory research was found regarding lean patients with PCOS. The aim of this narrative review is to shed light on the debate prevailing regarding characteristics, as well as metabolic, hematological, and potential management modalities. Literature review was performed from January 1, 2000 to March 31, 2017 with specific word search such as lean PCOS, hormonal abnormalities in lean PCOS, and the management of lean PCOS. All retrieved articles were carefully assessed, and data were obtained. We could conclude that the debate is still prevailing regarding this specific lean population with PCOS, especially with regard to their characteristics and management modalities. Further studies are still required to resolve this debate on the presence of PCOS in lean women.

Metformin Treatment and Homocysteine: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The aim of this systematic review is to assess whether metformin could change the concentration of serum homocysteine (Hcy) with and without simultaneous supplementation of B-group vitamins or folic acid. A literature search was conducted in PubMed, EmBase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomized controlled trials (RCTs) reporting the concentration of serum Hcy in metformin-treated adults. Meta-analysis was applied to assess the association between metformin and the changes of Hcy concentration. Twelve publications were included in this study. In the overall analysis, metformin administration was not statistically associated with the change of Hcy when compared with the control treatment (mean difference (MD), 0.40 μmol/L; 95% confidence interval (CI), -0.07~0.87 μmol/L, p = 0.10). In the subgroup analysis, metformin was significantly associated with an increased concentration of Hcy in the absence of exogenous supplementation of folic acid or B-group vitamins (MD, 2.02 μmol/L; 95% CI, 1.37~2.67 μmol/L, p < 0.00001), but with a decreased concentration of serum Hcy in the presence of these exogenous supplementations (MD, -0.74 μmol/L; 95% CI, -1.19~-0.30 μmol/L, p = 0.001). Therefore, although the overall effect of metformin on the concentration of serum Hcy was neutral, our results suggested that metformin could increase the concentration of Hcy when exogenous B-group vitamins or folic acid supplementation was not given.

Association of Prooxidant-Antioxidant Balance with Clinical and Laboratory Parameters and Its Relation to Different Drug Regimens in Polycystic Ovary Syndrome Women with Normal BMI

Polycystic ovarian syndrome is one of the most common hormonally leading cause infertility disorders. The effect of oxidant-antioxidant imbalance on disease progression has been studied in many disorders. The present study was aimed to evaluate prooxidant-antioxidant balance (PAB) in patients with polycystic ovarian syndrome compared to healthy subjects. We also studied the possible effect of treatment with available drugs on serum PAB. In this case-control study 100 polycystic ovary syndrome (PCOS) patients and 100 healthy individuals were enrolled in the study. The laboratory features of patients and controls like as serum LH and FSH concentration and hematological examinations were collected. PAB was evaluated by a colorimetric method. Serum PAB value was significantly higher before treatment compared to after treatment and healthy subjects. PAB values were also higher in subjects with irregular menstrual cycle compared to normal subjects. Our results represented that serum PAB values has an indirect significant correlation with serum LH concentration. We also found that drugs regimen containing spironolactone effectively reduced the serum PAB values. Our results showed that PCOS patients had increased level of PAB and treatment with spironolactone mainly decreases the level of serum PAB. Our results indicate that the measurements of PAB may be used as a potential laboratory marker for assessment of PCOS patients.

Association between High Serum Homocysteine Levels and Biochemical Characteristics in Women with Polycystic Ovarian Syndrome: A Systematic Review and Meta-Analysis

Background

Elevated homocysteine levels have been observed in previous studies of PCOS; however, the nature of the associations between high homocysteine levels and the biochemical characteristics of polycystic ovarian syndrome (PCOS)—such as obesity, insulin resistance (IR), and androgen levels—is still uncertain.

Methods

A systematic search was conducted electronically up to December 28, 2015 using specific eligibility criteria. Standardized mean difference (SMD) and the corresponding 95% confidence intervals (95% CIs) were used as a measure of effect size.

Results

A total of 34 studies (with 1,718 cases and 1,399 controls) of homocysteine levels in PCOS were pooled in this meta-analysis. Significantly lower homocysteine levels were found in controls than in PCOS patients (SMD = 0.895, 95% CI = 0.643–1.146, P<0.001; I² = 90.4% and P<0.001 for heterogeneity), regardless of the degree of obesity, IR, or androgen levels. Homocysteine levels in non-IR PCOS patients were significantly lower than those of PCOS patients with IR (SMD = 0.69, 95% CI = 0.37–1.01, P<0.01; I² = 0% and P = 0.50 for heterogeneity). However, metformin treatment did not appear to cause any significant change in the homocysteine levels of PCOS patients (SMD = –0.17, 95% CI = –1.10–0.75, P = 0.71; I² = 92% and P<0.01 for heterogeneity).

Conclusions

High homocysteine levels in women with PCOS are not related to degree of obesity, IR, or androgen levels. Metformin treatment cannot decrease the homocysteine levels in PCOS patients.

Poly Cystic Ovarian Syndrome: An Updated Overview

Poly Cystic Ovarian Syndrome (PCOS) is one of the most common metabolic and reproductive disorders among women of reproductive age. Women suffering from PCOS present with a constellation of symptoms associated with menstrual dysfunction and androgen excess, which significantly impacts their quality of life. They may be at increased risk of multiple morbidities, including obesity, insulin resistance, type II diabetes mellitus, cardiovascular disease (CVD), infertility, cancer, and psychological disorders. This review summarizes what the literature has so far provided from guidelines to diagnosis of PCOS. It will also present a general overview about the morbidities associated with this disease, specifically with its more severe classic form. Finally, the review will stress on the various aspects of treatment and screening recommendations currently used in the management of this condition.

N-Acetylcysteine improves oocyte and embryo quality in polycystic ovary syndrome patients undergoing intracytoplasmic sperm injection: an alternative to metformin

Polycystic ovary syndrome (PCOS) is associated with low-quality oocytes. The aim of the present study was to investigate the effects of metformin (MET), N-acetylcysteine (NAC) and their combination on follicular fluid parameters, oocytes and embryo quality in PCOS patients. A prospective randomised placebo-controlled pilot study on 60 Iranian women with PCOS (aged 25–35 years) undergoing intracytoplasmic sperm injection (ICSI) was designed. Women were divided into four groups (n = 15 in each): (1) an MET, administered 1500 mg day–1 MET; (2) an NAC group, administered 1800 mg day–1 NAC; (3) an NAC + MET group; and (4) a placebo group. Drugs were administered from the 3rd day of previous cycle until the day of oocyte aspiration (6 weeks treatment in total). Data were analysed by one-way ANOVA, with significance set at P < 0.05. The number of immature and abnormal oocytes decreased significantly in the NAC compared with placebo group, with a concomitant increase in the number of good-quality embryos in the NAC group (P < 0.05). Malondialdehyde levels decreased significantly in the NAC and NAC + MET groups compared with the placebo-treated group (P < 0.02). In addition, there were significant decreases in leptin levels in the NAC, MET and NAC + MET groups compared with the placebo group (P < 0.001). Insulin and LH levels were significantly lower in the MET and NAC groups compared with the placebo-treated group (P < 0.02). We concluded that NAC improves oocyte and embryo quality and could be administered as an alternative to MET.

Roles of Oxidative Stress in Polycystic Ovary Syndrome and Cancers

Oxidative stress (OS) has received extensive attention in the last two decades, because of the discovery that abnormal oxidation status was related to patients with chronic diseases, such as diabetes, cardiovascular, polycystic ovary syndrome (PCOS), cancer, and neurological diseases. OS is considered as a potential inducing factor in the pathogenesis of PCOS, which is one of the most common complex endocrine disorders and a leading cause of female infertility, affecting 4%–12% of women in the world, as OS has close interactions with PCOS characteristics, just as insulin resistance (IR), hyperandrogenemia, and chronic inflammation. It has also been shown that DNA mutations and alterations induced by OS are involved in cancer pathogenesis, tumor cell survival, proliferation, invasion, angiogenesis, and so on. Furthermore, recent studies show that the females with PCOS are reported to have an increasing risk of cancers. As a result, the more serious OS in PCOS is regarded as an important potential incentive for the increasing risk of cancers, and this study aims to analyze the possibility and potential pathogenic mechanism of the above process, providing insightful thoughts and evidences for preventing cancer potentially caused by PCOS in clinic.

Postprandial Dysmetabolism and Oxidative Stress in Type 2 Diabetes: Pathogenetic Mechanisms and Therapeutic Strategies

Postprandial dysmetabolism in type 2 diabetes (T2D) is known to impact the progression and evolution of this complex disease process. However, the underlying pathogenetic mechanisms still require full elucidation to provide guidance for disease prevention and treatment. This review focuses on the marked redox changes and inflammatory stimuli provoked by the spike in blood glucose and lipids in T2D individuals after meals. All the causes of exacerbated postprandial oxidative stress in T2D were analyzed, also considering the consequence of enhanced inflammation on vascular damage. Based on this in-depth analysis, current strategies of prevention and pharmacologic management of T2D were critically reexamined with particular emphasis on their potential redox-related rationale.

Evaluation of the Association Metformin: Plantago ovata Husk in Diabetic Rabbits

In this experimental study we have investigated whether the inclusion of the dietary fiber Plantago ovata husk could be recommended as coadjuvant in treatments with oral hypoglycemic drugs. We evaluated the use of Plantago ovata husk-metformin association in diabetic rabbits by determining its effects on glucose and insulin concentrations. Six groups of 6 rabbits were used. Groups 1 to 3 were fed with standard chow and groups 4 to 6 with chow supplemented with Plantago ovata husk (3.5 mg/kg/day). Two groups (numbers 1 and 4) were used as controls (receiving standard or supplemented chow), two groups (numbers 2 and 5) received metformin orally, and the other two (numbers 3 and 6) were treated orally with metformin and psyllium. Plasma glucose concentrations were lower in groups fed with fiber-supplemented chow whereas insulin levels showed important interindividual variations. Glucose pharmacokinetics parameters showed significant differences in Cmax and t(max) in relation to fiber intake. Insulin pharmacokinetics parameters after treatment with oral metformin showed an important increase in Cmax, AUC, and t(max) in animals fed with fiber. We conclude that Plantago ovata husk intake can contribute to the oral antihyperglycemic treatment of type 2 diabetes.

Oxidative stress in non-obese women with polycystic ovarian syndrome

BACKGROUND

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine diseases of women. Oxidative stress is an important component of the cardio-metabolic risk seen in these women. Oxidative stress has been reported in obese PCOS women. This study is taken up to study oxidative stress in non-obese PCOS women.

MATERIALS AND METHODS

Twenty five non-obese women with PCOS attending the Endocrinology outpatient Department of Sri Venkateswara Institute of Medical Sciences, Tirupati, India along with 25 healthy BMI matched controls were included in the study. The changes in the lipid peroxidation products (MDA), and total anti oxidant capacity (FRAP) as an index of anti oxidant status along with fasting glucose, insulin and uric acid levels were measured in both groups. Insulin resistance was evaluated by using homeostasis model assessment for insulin resistance [HOMA-IR)= [FPG (mg/dl) × insulin (mIU/L)]/ 405] in both groups.

RESULTS

Serum MDA and uric acid levels were increased in the study group compared with controls and FRAP levels were decreased in the study group compared to controls though statistically insignificant.

CONCLUSION

Oxidative stress is also present in non-obese women with PCOS. Oxidative stress further increases the CVD risk in these women.Correcting oxidative stress with antioxidants along with monitoring the antioxidant status using a simple assay like FRAP could have a beneficial effect on oxidative stress induced insulin resistance and hyperandrogenism seen in these women.

The effects of metformin on endothelial dysfunction, lipid metabolism and oxidative stress in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder, which is considered not only a reproductive disease but also a metabolic disorder associated with long-term health risks. The aim of this study was to assess the effects of metformin on insulin resistance, oxidant-antioxidant status, endothelial dysfunction, lipid metabolism and their contribution to the risks of cardiovascular disease in women with PCOS. Fifteen women with PCOS and 17 healthy women were included in this case-control study. Nitric oxide (NO), endothelin-1 (ET-1), malondialdehyde (MDA), Apo A1, Apo B, small, dense LDL cholesterol (sdLDL-C), lipid levels and paraoxonase 1 (PON1) activity were measured in serum/plasma obtained from study groups. Insulin resistance (HOMA index - Homeostasis Model Assessment) and serum sex hormone profiles were also evaluated. Significantly decreased NO levels and PON1 activities, but increased MDA, ET-1 and sdLDL-C were found in PCOS patients compared to those of controls. Serum MDA, ET-1, HOMA and sdLDL-C levels decreased and PON1 activity and NO levels increased significantly after the metformin treatment. There was a positive correlation between MDA and free testosterone (fT), ET-1 and fT; and a negative correlation between PON1 activity and fT. Insulin resistance, dyslipidemia, endothelial dysfunction and oxidative stress might contribute to the excess risk of cardiovascular disease reported in PCOS. Metformin seemed to decrease oxidative stress and improve insulin resistance, dyslipidemia and endothelial dysfunction in PCOS patients.

Effects of rosiglitazone on serum paraoxonase activity and metabolic parameters in patients with type 2 diabetes mellitus

Human serum paraoxonase contributes to the anti-atherogenic effect of high-density lipoprotein cholesterol (HDL-C) and has been shown to protect both low-density lipoprotein cholesterol (LDL-C) and HDL-C against lipid peroxidation. We investigated the effects of rosiglitazone on paraoxonase activity and metabolic parameters in patients with type 2 diabetes mellitus [50 patients (30 males, 20 females); mean±SD age: 58.7±9.2 years, body mass index: 28.2±4.1'kg/m²], in whom glucose control could not be achieved despite treatment with metformin, sulphonylurea, and/or insulin. The patients were given 4'mg/day rosiglitazone for 3 months in addition to their usual treatment. Serum paraoxonase activity, malondialdehyde, homocysteine, and lipid profile were measured at the time of initiation and at the end of therapy with rosiglitazone. After rosiglitazone therapy, serum levels of HDL-C, apolipoprotein A-1, and paraoxonase activity increased significantly (P<0.05) and malondialdehyde, homocysteine, lipoprotein(a), and glucose levels decreased significantly (P<0.05), but no significant changes in levels of total cholesterol and apolipoprotein B were observed. Triglyceride levels also increased significantly (P<0.05). Rosiglitazone treatment led to an improvement in glycemic control and to an increase in paraoxonase activity and HDL-C levels. Although rosiglitazone showed favorable effects on oxidant/antioxidant balance and lipid profile, further studies are needed to determine the effect of rosiglitazone on cardiovascular risk factors and cardiovascular morbidity and mortality.