One-year effects of myo-inositol supplementation in postmenopausal women with metabolic syndrome

Early Life Programming of Adipose Tissue Remodeling and Browning Capacity by Micronutrients and Bioactive Compounds as a Potential Anti-Obesity Strategy

The early stages of life, especially the period from conception to two years, are crucial for shaping metabolic health and the risk of obesity in adulthood. Adipose tissue (AT) plays a crucial role in regulating energy homeostasis and metabolism, and brown AT (BAT) and the browning of white AT (WAT) are promising targets for combating weight gain. Nutritional factors during prenatal and early postnatal stages can influence the development of AT, affecting the likelihood of obesity later on. This narrative review focuses on the nutritional programming of AT features. Research conducted across various animal models with diverse interventions has provided insights into the effects of specific compounds on AT development and function, influencing the development of crucial structures and neuroendocrine circuits responsible for energy balance. The hormone leptin has been identified as an essential nutrient during lactation for healthy metabolic programming against obesity development in adults. Studies have also highlighted that maternal supplementation with polyunsaturated fatty acids (PUFAs), vitamin A, nicotinamide riboside, and polyphenols during pregnancy and lactation, as well as offspring supplementation with myo-inositol, vitamin A, nicotinamide riboside, and resveratrol during the suckling period, can impact AT features and long-term health outcomes and help understand predisposition to obesity later in life.

Dietary Supplementation of Myo-Inositol, Cocoa Polyphenols, and Soy Isoflavones Improves Vasomotor Symptoms and Metabolic Profile in Menopausal Women with Metabolic Syndrome: A Retrospective Clinical Study

Background and Objectives: Hormonal changes physiologically occurring in menopausal women may increase the risk of developing metabolic and vasomotor disturbances, which contribute to increase the risk of developing other concomitant pathologies, such as metabolic syndrome (MetS). Materials and Methods: Retrospective data from 200 menopausal women with MetS and vasomotor symptoms taking one sachet per day of the dietary supplement INOFOLIC® NRT (Farmares srl, Rome, Italy) were collected. Each sachet consisted of myo-Inositol (2000 mg), cocoa polyphenols (30 mg), and soy isoflavones (80 mg, of which 50 mg is genistin). Patients recorded their symptoms through a medical questionnaire at the beginning of the administration (T0) and after 6 months (T1). Results: We observed an improvement in both the frequency and the severity of hot flushes: increased percentage of 2-3 hot flushes (28 at T0 vs. 65% at T1, p value < 0.001) and decreased percentage of 4-9 hot flushes (54% at T0 vs. 18% at T1, p value < 0.001). Moreover, symptoms of depression improved after supplementation (87% at T0 vs. 56% at T1 of patients reported moderate depression symptoms, p value < 0.001). Regarding metabolic profile, women improved body mass index and waist circumference with a reduction in the percentage of overweight and obesity women (88% at T0 vs. 51% at T1, p value = 0.01; 14% at T0 vs. 9% at T1, p value = 0.04). In addition, the number of women suffering from non-insulin dependent diabetes reduced (26% at T0 vs. 16% at T1, p value = 0.04). Conclusions: These data corroborate previously observed beneficial effects of the oral administration of myo-Inositol, cocoa polyphenols, and soy isoflavones against menopausal symptoms in the study population. Considering the promising results of the present study, further prospective controlled clinical trials are needed to deeply understand and support the efficacy of these natural compounds for the management of menopausal symptoms.

The role of myo-inositol supplement in assisted reproductive techniques

Assisted reproductive techniques can help many infertile couples conceive. Therefore, there is a need for an effective method to overcome the widespread problems of infertile men and women. Oocyte and sperm quality can increase the chances of successful in vitro fertilisation. The maturation environment in which gametes are present can affect their competency for fertilisation. It is well established that myo-inositol (MI) plays a pivotal role in reproductive physiology. It participates in cell membrane formation, lipid synthesis, cell proliferation, cardiac regulation, metabolic alterations, and fertility. This molecule also acts as a direct messenger of insulin and improves glucose uptake in various reproductive tissues. Evidence suggests that MI regulates events such as gamete maturation, fertilisation, and embryo growth through intracellular Ca2 + release and various signalling pathways. In addition to the in-vivo production of MI from glucose in the reproductive organs, its synthesis by in vitro-cultured sperm and follicles has also been reported. Therefore, MI is suggested as a therapeutic approach to maintain sperm and oocyte health in men and women with reproductive disorders and individuals of reproductive age.

Plant foods, healthy plant-based diets, and type 2 diabetes: a review of the evidence

Type 2 diabetes (T2D) is a metabolic chronic disease in which insulin resistance and insufficient insulin production lead to elevated blood glucose levels. The prevalence of T2D is growing worldwide, mainly due to obesity and the adoption of Western diets. Replacing animal foods with healthy plant foods is associated with a lower risk of T2D in prospective studies. In randomized controlled trials, the consumption of healthy plant foods in place of animal foods led to cardiometabolic improvements in patients with T2D or who were at high risk of the disease. Dietary patterns that limit or exclude animal foods and focus on healthy plant foods (eg, fruits, vegetables, whole grains, nuts, legumes), known as healthy, plant-based diets, are consistently associated with a lower risk of T2D in cohort studies. The aim of this review is to examine the differential effects of plant foods and animal foods on T2D risk and to describe the existing literature about the role of healthy, plant-based diets, particularly healthy vegan diets, in T2D prevention and management. The evidence from cohort studies and randomized controlled trials will be reported, in addition to the potential biological mechanisms that seem to be involved.

Myo-inositol improves the viability of boar sperm during liquid storage

Introduction

Liquid preservation of boar semen is a highly preferred method for semen preservation in pig production. However, oxidative stress is the main challenge during the liquid preservation of boar semen in a time dependent manner. Therefore, supplementation of sperm with antioxidants during storage to protect them from oxidative stress has been the focus of recent research. Myo-inositol (Myo-Ins), the most active form of inositol, which belongs to the vitamin (Vit.) (B1 group has been shown to improve semen quality) (1). This study aimed to investigate whether Myo-Ins supplementation protects boar sperm in liquid preservation against oxidative stress and determine the appropriate concentration of Myo-Ins to be used in this regard.

Methods

Boar sperm was diluted with a semen extender with different concentrations of Myo-Ins (2, 4, 6, and 8 mg/mL) depending on the previous studies (1, 24). Sperm motility and viability, plasma membrane and acrosome integrity, mitochondrial membrane potential (MMP), semen time survival, and gene expression were measured and analyzed on days 0, 1, 3, 5, and 7 for the different samples.

Results

Different concentrations of Myo-Ins exerted different protective effects on the boar sperm quality. The addition of 2 mg/mL Myo-Ins resulted in higher sperm motility and viability, plasma membrane and acrosome integrity, MMP, and effective survival time. Investigation of mRNA expression patterns via qRT-PCR suggested that the 2 mg/mL Myo-Ins sample had increased expression of antioxidative genes.

Conclusion

The addition of Myo-Ins to semen extender improved the boar semen quality by decreasing the effects of oxidative stress during liquid preservation at 17°C. Additionally, 2 mg/mL is the optimum inclusion concentration of Myo-Ins for semen preservation.

Myo-inositol supplementation for prevention of gestational diabetes mellitus in overweight and obese pregnant women: a systematic review and meta-analysis

BACKGROUND

The prevalence of gestational diabetes mellitus [GDM] and of its most important predisposing factor, i.e. overweight and obesity, have increased dramatically over the past 20 years. Therefore, the aim of this study was to systematically review the articles on the effect of myo-inositol supplementation on the prevention of GDM in pregnant women with overweight and obesity.

METHODS

We conducted a systematic literature search in electronic database (MEDLINE, Cochrane Library, ClinicalTrials.gov, Embase, ProQuest, PubMed, Google scholar, Scopus, Web of science and forward and backward citations) to identify all randomized controlled trials (RCTs) published until 21 December 2021. Finally, Among the 118 identified records, four studies were eligible and were included in this systematic review. The meta-analysis results were reported in the form of odds ratio (OR) to compare the incidence of GDM and pregnancy outcomes. They were also presented in the form of mean difference (MD) to compare fasting glucose (FG), 1-h and 2-h oral glucose tolerance test (OGTT) levels between the two groups. This study was registered on PROSPERO, number CRD42021290570.

RESULTS

The results showed that the incidence of GDM was significantly lower in the myo-inositol group (OR 0.32, 95% CI 0.21 to 0.48; P < 0.001; I² = 0%; Moderate certainty evidence). Moreover, FG-OGTT (MD - 2.64 mg/dl, 95% CI - 4.12 to - 1.17; P < 0.001; I² = 0%; Moderate certainty evidence), 1-h-OGTT (MD - 7.47 mg/dl, 95% CI - 12.24 to - 2.31; P = 0.005; I² = 27%; Low certainty evidence) and 2-h-OGTT levels (MD - 10.51 mg/dl, 95% CI - 16.88 to - 4.14; P = 0.001; I² = 59%; Low certainty evidence) in the myo-inositol group were significantly lower than in the control group. Regarding the pregnancy outcomes, the incidence of gestational hypertension and preterm delivery was significantly lower in the myo-inositol group. However, no between-group difference was observed in the other outcomes.

CONCLUSIONS

Based on the results, myo-inositol has shown to be a new and safe preventive strategy in reducing the incidence of GDM and in regulating FG and 1-h and 2-h OGTT levels, and also in reducing the incidence of GDM complications such as preterm delivery and gestational hypertension in pregnant women with overweight and obesity.

Inositol supplementation and body mass index: A systematic review and meta‐analysis of randomized clinical trials

Background

Inositol is a sugar‐alcohol and recognized as a key component of cell membrane phospholipids. It has crucial role in the cell signaling pathways and contribute to improving glycemic responses. Although some earlier studies have revealed the effect of inositol mediating glucose uptake by improving insulin sensitivity, the benefit of inositol supplementation in patients with overweight and obesity is not completely understood. This study aimed to assess the impact of inositol supplementation on body mass index (BMI) through a systematic review and meta‐analysis of controlled clinical trials.

Methods

A systematic search was performed to August 2021 in the following databases: PubMed‐Medline, Embase, Web of Science and Scopus. Fifteen controlled clinical trials investigating the effect of inositol on adult's BMI were finally included in the study. A random‐effects model was employed to estimate the effect size. Subgroup analysis was performed by dose, duration, age, type of inositol. Meta‐regression was used to investigate presence of any linear relationship. Begg's and Egger's tests were carried out to detect small study effect.

Results

The results of pooled analysis showed that inositol supplementation significantly decreased BMI scores (WMD = −0.41 kg/m²; 95% CI: −0.78, −0.04; p = 0.028). Subgroup analysis was performed to identify the source of heterogeneity among studies (I² = 73.9%, p < 0.001), demonstrating supplementation duration, baseline BMI, mean age of participants, type of inositol and dosage were potential sources of heterogeneity. The effect of intervention was more clinically significant in participants with polycystic ovary syndrome (PCOS) and overweight/obesity. Inositol in the form of myo‐inositol (MI) had stronger effect on BMI reduction.

Conclusion

The meta‐analysis suggests that oral inositol supplementation has positive effect on BMI reduction. Inositol supplementation could be considered as an adjunct treatment to improve body mass index.

The effect of inositol supplementation on blood pressure: A systematic review and meta-analysis of randomized-controlled trials

BACKGROUND & AIMS

Potential effects of inositol supplementation on blood pressure (BP) have been examined in several interventional studies. Nevertheless, findings in this context are controversial. Therefore, the current systematic review and meta-analysis aimed to comprehensively assess the impact of inositol supplementation on BP.

METHODS

Five online databases including Web of Science, Scopus, Embase, Cochrane, Google Scholar, and PubMed were systematically searched from inception to March 2020. We included all randomized clinical trials (RCTs) evaluating the effects of inositol supplementation on systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) in humans.

RESULTS

The random-effects meta-analysis of 7 eligible RCTs demonstrated the significant decline in both SBP (WMD - 5.69 mmHg; 95% CI - 7.35 to - 4.02, P < 0.001) and DBP (WMD - 7.12 mmHg; 95% CI - 10.18 to - 4.05, P < 0.001) following supplementation with inositol. Subgroup analysis showed that studies performed in individuals with metabolic syndrome with a longer duration (>8 weeks) and a dose of 4000 mg resulted in a more effective reduction in SBP and DBP with acceptable homogeneity.

CONCLUSIONS

The current meta-analysis, indicated that supplementation with inositol significantly decrease SBP and DBP. Further large-scale RCTs with better design are needed to confirm these findings.

Identification of biomarkers for essential hypertension based on metabolomics

AIM

Essential hypertension (EH) is one of the most important public health problems worldwide. However, the pathogenesis of EH is unclear and early diagnostic methods are lacking. Metabolomics demonstrates great potential for biomarker discovery and the mechanistic exploration of metabolic diseases.

DATA SYNTHESIS

This review included human and animal metabolomics studies related to EH in the PubMed and Web of Science databases between February 1996 and May 2020. The study designs, EH standards, and reported metabolic biomarkers were systematically examined and compared. The pathway analysis was conducted through the online software MetaboAnalyst 4.0. Twenty-two human studies and fifteen animal studies were included in this systematic review. There were many frequently reported biomarkers with consistent trends (e.g., pyruvate, lactic acid, valine, and tryptophan) in human and animal studies, and thus had potential as biomarkers of EH. In addition, several shared metabolic pathways, including alanine, aspartate, and glutamate metabolism, aminoacyl-tRNA biosynthesis, and arginine biosynthesis, were identified in human and animal metabolomics studies. These biomarkers and pathways, closely related to insulin resistance, the inflammatory state, and impaired nitric oxide production, were demonstrated to contribute to EH development.

CONCLUSIONS

This study summarized valuable metabolic biomarkers and pathways that could offer opportunities for the early diagnosis or prediction of EH and the discovery of the metabolic mechanisms of EH.

D-Chiro-Inositol Regulates Insulin Signaling in Human Adipocytes

D-Chiro-Inositol (D-Chiro-Ins) is a secondary messenger in the insulin signaling pathway. D-Chiro-Ins modulates insulin secretion, the mitochondrial respiratory chain, and glycogen storage. Due to these actions D-Chiro-Ins has been proposed to correct defective insulin function in a variety of conditions characterized by metabolic dysfunction, such as polycystic ovary syndrome (PCOS), obesity, gestational diabetes and fat accumulation at menopause. Since it is unclear whether D-Chiro-Ins directly acts on adipocytes, we aimed to study D-Chiro-Ins's actions on adipocyte viability, proliferation, differentiation, and insulin-related protein expression using a human adipocyte cell line derived from Simpson-Golabi-Behmel Syndrome (SGBS) which fully differentiates to mature adipocytes. Throughout differentiation, cells were treated with D-Chiro-Ins, 17β-estradiol (E2) or Insulin. Cell viability and proliferation were not affected by D-Chiro-Ins, then D-Chiro-Ins promoted cell differentiation only during the final days of the process, while E2 enhanced it from the first phases. D-Chiro-Ins stimulated lipid storage and the production of big lipid droplets, thus reducing the content of free fatty acids. We also found that D-Chiro-Ins, either alone or in combination with insulin and E2 increased the expression and activation of insulin receptor substrate-1 (IRS1) and glucose transporter type 4 (GLUT4). In conclusion, this work shows that D-Chiro-Ins plays a direct role in the differentiation and in the function of human adipocytes, where it synergizes with insulin and estrogen through the recruitment of signal transduction pathways involved in lipid and glucose storage. These findings give clear insights to better understand the actions of D-Chiro-Ins on fat metabolism in women in physiology and in a variety of diseases.

A review of the role of inositols in conditions of insulin dysregulation and in uncomplicated and pathological pregnancy

Inositols, a group of 6-carbon polyols, are highly bioactive molecules derived from diet and endogenous synthesis. Inositols and their derivatives are involved in glucose and lipid metabolism and participate in insulin-signaling, with perturbations in inositol processing being associated with conditions involving insulin resistance, dysglycemia and dyslipidemia such as polycystic ovary syndrome and diabetes. Pregnancy is similarly characterized by substantial and complex changes in glycemic and lipidomic regulation as part of maternal adaptation and is also associated with physiological alterations in inositol processing. Disruptions in maternal adaptation are postulated to have a critical pathophysiological role in pregnancy complications such as gestational diabetes and pre-eclampsia. Inositol supplementation has shown promise as an intervention for the alleviation of symptoms in conditions of insulin resistance and for gestational diabetes prevention. However, the mechanisms behind these affects are not fully understood. In this review, we explore the role of inositols in conditions of insulin dysregulation and in pregnancy, and identify priority areas for research. We particularly examine the role and function of inositols within the maternal-placental-fetal axis in both uncomplicated and pathological pregnancies. We also discuss how inositols may mediate maternal-placental-fetal cross-talk, and regulate fetal growth and development, and suggest that inositols play a vital role in promoting healthy pregnancy.

The Effect of Preincubation Time and Myo-inositol Supplementation on the Quality of Mouse MII Oocytes

Background:

It is demonstrated that optimal preincubation time improves oocyte quality, fertilization potential and developmental rate. This study aimed to evaluate the effect of preincubation time in the simple and myo-inositol supplemented medium on the oocyte quality regarding oxidative stress and mitochondrial alteration.

Methods:

Cumulus oocyte complexes (COCs) retrieved from superovulated NMRI mice were divided in groups of 0, 4 and 8 hr preincubation time in the simple and 20 mmol/L myo-inositol supplemented media. Intracellular reactive oxygen species (H₂O₂), glutathione (GSH), mitochondrial membrane potential (MMP), ATP content, and mitochondrial amount were measured and analyzed in experimental groups. One-way ANOVA and Kruskal-Wallis were respectively used for parametric and nonparametric variables. Statistical significance was defined as p<0.05.

Results:

In comparison to control group, variables including ROS, GSH, mitochondrial amount, fertilization and developmental rates were significantly changed after 4 hr of preincubation in the simple medium, while MMP decreased following 8 hr of preincubation in the simple medium (p˂0.001). Preincubation of oocytes up to 8 hr in the simple medium could not decrease ATP content. For both 4 and 8 hr preincubation times, myo-inositole could decrease H₂O₂ and increase GSH and MMP levels and consequently could improve fertilization rate compared to oocytes preincubated in the simple culture.

Conclusion:

It seems that 4 hr or more preincubation time can decrease the oocyte quality and lead to reduced oocyte fertilization and developmental potential. Howevere, myo-inositol may prevent oocyte quality reduction and improve fertilization potential in comparision to the equivalent simple groups.

Inositol and Non-Alcoholic Fatty Liver Disease: A Systematic Review on Deficiencies and Supplementation

Liver lipid accumulation is a hallmark of non-alcoholic fatty liver disease (NAFLD), broadly associated with insulin resistance. Inositols (INS) are ubiquitous polyols implied in many physiological functions. They are produced endogenously, are present in many foods and in dietary supplements. Alterations in INS metabolism seems to play a role in diseases involving insulin resistance such as diabetes and polycystic ovary syndrome. Given its role in other metabolic syndromes, the hypothesis of an INS role as a supplement in NAFLD is intriguing. We performed a systematic review of the literature to find preclinical and clinical evidence of INS supplementation efficacy in NAFLD patients. We retrieved 10 studies on animal models assessing Myoinosiol or Pinitol deficiency or supplementation and one human randomized controlled trial (RCT). Overall, INS deficiency was associated with increased fatty liver in animals. Conversely, INS supplementation in animal models of fatty liver reduced hepatic triglycerides and cholesterol accumulation and maintained a normal ultrastructural liver histopathology. In the one included RCT, Pinitol supplementation obtained similar results. Pinitol significantly reduced liver fat, post-prandial triglycerides, AST levels, lipid peroxidation increasing glutathione peroxidase activity. These results, despite being limited, indicate the need for further evaluation of INS in NAFLD in larger clinical trials.

The precursor of PI(3,4,5)P3 alleviates aging by activating daf-18(Pten) and independent of daf-16

Aging is characterized by the loss of homeostasis and the general decline of physiological functions, accompanied by various degenerative diseases and increased rates of mortality. Aging targeting small molecule screens have been performed many times, however, few have focused on endogenous metabolic intermediates-metabolites. Here, using C. elegans lifespan assays, we conducted a worm metabolite screen and identified an eukaryotes conserved metabolite, myo-inositol (MI), to extend lifespan, increase mobility and reduce fat content. Genetic analysis of enzymes in MI metabolic pathway suggest that MI alleviates aging through its derivative PI(4,5)P2. MI and PI(4,5)P2 are precursors of PI(3,4,5)P3, which is negatively related to longevity. The longevity effect of MI is dependent on the tumor suppressor gene, daf-18 (homologous to mouse Pten), independent of its classical pathway downstream genes, akt or daf-16. Furthermore, we found MI effects on aging and lifespan act through mitophagy regulator PTEN induced kinase-1 (pink-1) and mitophagy. MI's anti-aging effect is also conserved in mouse, indicating a conserved mechanism in mammals.

Effect of dietary myo-inositol supplementation on the insulin resistance and the prevention of gestational diabetes mellitus: study protocol for a randomized controlled trial

Background

Gestational diabetes mellitus (GDM) is defined as impaired glucose tolerance with onset or first recognition during pregnancy, which is characterized by an increased insulin resistance. Gestational diabetes mellitus is associated with pregnancy-related maternal and fetal morbidity (both antenatal and perinatal).

Myo-inositol has been suggested to improve insulin resistance in women with polycystic ovary syndrome.

The aim of this study is to examine the impact of myo-inositol supplementation during pregnancy on the incidence of gestational diabetes mellitus.

Methods

We will conduct a single-center, open-label, randomized controlled trial. A total of 160 healthy pregnant women with singleton pregnancy at 11–13⁺⁶ weeks of gestation will be randomly allocated in two groups: intervention group (N = 80) and control group (N = 80). The intervention group will receive myo-inositol and folic acid (4000 mg myo-inositol and 400 mcg folic acid daily) from 11 to 13⁺⁶ weeks of gestation until 26–28 weeks of gestation, while the control group will receive folic acid alone (400 mcg folic acid daily) for the same period of time as intervention group. The primary outcome will be gestational diabetes incidence rate at 26–28 weeks of gestation, according to the results of a 75 g oral glucose tolerance test held at 26–28 weeks of gestation. The secondary outcomes will include fasting blood glucose levels, glycated hemoglobin levels, insulin resistance level (evaluated by homeostasis model assessment of insulin resistance and Matsuda Index), and incidence rate of diet-treated gestational diabetes and diabetes requiring insulin therapy at 26–28 weeks of gestation.

Discussion

This trial will provide evidence for the effectiveness of myo-inositol supplementation during pregnancy in reducing the incidence of gestational diabetes mellitus.

Trial registration

ISRCTN registry: ISRCTN16142533. Registered on 9 March 2017.

An Evaluation of a Nutraceutical with Berberine, Curcumin, Inositol, Banaba and Chromium Picolinate in Patients with Fasting Dysglycemia

AIM

To evaluate if a nutraceutical containing Berberine, Curcumin, Inositol, Banaba, and Chromium Picolinate (Reglicem^®), can ameliorate glycemic status in patients with dysglycemia.

METHODS

We enrolled 148 patients with impaired fasting plasma glucose or impaired glucose tolerance, not taking any hypoglycemic compounds. Patients were randomized to take nutraceutical or placebo for 3 months, in a randomized, double-blind, placebo-controlled design. Both nutraceutical and placebo were self-administered once a day, 1 tablet during the breakfast.

RESULTS

A reduction of fasting and post-prandial plasma glucose was observed with the nutraceutical combination (p < 0.05 vs baseline and p < 0.05 vs placebo, respectively). Furthermore, a decrease of glycated hemoglobin, and fasting plasma insulin was observed with the nutraceutical combination (p < 0.05 vs baseline and p < 0.05 vs placebo, respectively). Then, there was a reduction of homeostasis model assessment index with the nutraceutical combination (p < 0.05 vs baseline and p < 0.05 vs placebo). M value was higher (p < 0.05 vs baseline and p < 0.05 vs placebo) in the nutraceutical combination group at the end of the treatment. We observed a reduction of total cholesterol (TC) (p < 0.05 vs baseline) and triglycerides (Tg) (p < 0.05 vs baseline and p < 0.05 vs placebo) with the nutraceutical combination, respectively. Finally, high sensitivity C-reactive protein was reduced after 3 months with nutraceutical combination therapy (p < 0.05 vs baseline and p < 0.05 vs placebo, respectively).

CONCLUSION

A nutraceutical containing Berberine, Curcumin, Inositol, Banaba, and Chromium Picolinate can be helpful in improving glyco-metabolic compensation, TC and Tg value, and in reducing inflammatory status in patients with dysglycemia.

Myoinositol Supplementation of Freezing Medium Improves the Quality-Related Parameters of Dog Sperm

Simple Summary

The generation of free radical reactive oxygen species during freeze–thaw procedures is one of the major factors affecting the function and survival of sperm. Myoinositol is the most important natural form of inositol produced in the human body. Researchers have attempted to exploit the antioxidant nature of myoinositol to treat human infertility issues via the improvement of sperm quality traits and fertilization rates. We investigated the potential role of myoinositol neutralizing free radicals produced during the cryopreservation of dog semen. Myoinositol supplementation in the freezing medium resulted in improved quality-related parameters of dog semen including percentage motility, viability, plasma membrane integrity, and chromatin integrity. Improvement in post-thaw semen quality was confirmed by the expression of genes related to apoptosis, nuclear integrity, and reactive oxygen species generation.

Abstract

Oxidative stress during freeze–thaw procedures results in reduced semen fertility. A decrease in free radical levels can improve the post-thaw sperm quality. We examined the effects of myoinositol supplementation in freezing medium on the structure and function of cryopreserved dog sperm. Pooled ejaculates were diluted with buffer without or with myoinositol (1 or 2 mg/mL). Analysis of fresh semen revealed that the optimal concentration of myoinositol was 1 mg/mL, and this concentration was used in further experiments. Post-thaw semen quality in the myoinositol-supplemented group was superior (p < 0.05) compared with that in the control group in terms of motility (57.9 ± 0.4% vs. 47.8 ± 0.2%), sperm viability (57.5 ± 0.5% vs. 44.6 ± 0.6%), intact plasma membrane (56.6 ± 0.4% vs. 46.2 ± 0.6%), and acrosome membrane (59.3 ± 0.5% vs. 51.8 ± 0.5%). In addition, sperm in the myoinositol-supplemented group showed a significantly lower expression of pro-apoptotic (BAX) and mitochondrial reactive oxygen species (ROS) modulator (ROMO1) genes but higher expression of anti-apoptotic (BCL2), and protamine-related (PRM2 and PRM3) genes compared with that in the control group. Therefore, myoinositol supplementation before freezing can protect against oxidative stress and improve post-thaw dog sperm quality.

Inositols in Insulin Signaling and Glucose Metabolism

In the past decades, both the importance of inositol for human health and the complex interaction between glucose and inositol have been the subject of increasing consideration. Glucose has been shown to interfere with cellular transmembrane transport of inositol, inhibiting, among others, its intestinal absorption. Moreover, intracellular glucose is required for de novo biosynthesis of inositol through the inositol-3-phosphate synthase 1 pathway, while a few glucose-related metabolites, like sorbitol, reduce intracellular levels of inositol. Furthermore, inositol, via its major isomers myo-inositol and D-chiro-inositol, and probably some of its phosphate intermediate metabolites and correlated enzymes (like inositol hexakisphosphate kinase) participate in both insulin signaling and glucose metabolism by influencing distinct pathways. Indeed, clinical data support the beneficial effects exerted by inositol by reducing glycaemia levels and hyperinsulinemia and buffering negative effects of sustained insulin stimulation upon the adipose tissue and the endocrine system. Due to these multiple effects, myoIns has become a reliable treatment option, as opposed to hormonal stimulation, for insulin-resistant PCOS patients.

Effects of inositol on glucose homeostasis: Systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

The effect of inositol on glucose homeostasis is not well characterized. The aim of the present meta-analysis is to synthesize the effects of inositol on glucose homeostasis in different clinical conditions.

METHODS

We performed a systematic review (CRD42017057927) following PRISMA guidelines. Web of Science and Medline were searched for randomized controlled trials (RCTs) that addressed supplementation with compounds of the inositol family in humans and assessed their effects on glucose homeostasis.

RESULTS

We screened 476 abstracts and included 20 RCTs with a total of 1239 subjects. Meta-analysis showed in the treatment arm a reduction in fasting plasma glucose (Mean difference (MD) -0.44 mmol/l, 95% CI -0.65, -0.23), 2 h PG after 75 g OGTT (MD -0.69 mmol/l, 95% CI -1.14, -0.23), abnormal glucose tolerance (Relative risk (RR) 0.28, 95% CI 0.12, 0.66), fasting insulin (MD -38.49 pmol/l, 95% CI -52.63, -24.36), and HOMA-IR (MD -1.96 mmol × mUI/l, 95% CI -2.62, -1.30). No differences were observed in BMI, HbA1c and % of patients requiring insulin treatment. Sensitivity analysis did not change treatment estimates. Mention to adverse events was only present in 13 articles with no sign of seriousness.

CONCLUSIONS

Inositol supplementation decreases blood glucose through an improvement in insulin sensitivity that is independent of weight. Assessment of adverse effects is scarce among published trials and should be fully addressed before considering inositol as a therapeutic agent for glucose-related outcomes. The characterization of the subjects achieving benefit from the intervention and the formulations to be used should also be known.

Do inositol supplements enhance phosphatidylinositol supply and thus support endoplasmic reticulum function?

This review attempts to explain why consuming extra myoinositol (Ins), an essential component of membrane phospholipids, is often beneficial for patients with conditions characterised by insulin resistance, non-alcoholic fatty liver disease and endoplasmic reticulum (ER) stress. For decades we assumed that most human diets provide an adequate Ins supply, but newer evidence suggests that increasing Ins intake ameliorates several disorders, including polycystic ovary syndrome, gestational diabetes, metabolic syndrome, poor sperm development and retinopathy of prematurity. Proposed explanations often suggest functional enhancement of minor facets of Ins Biology such as insulin signalling through putative inositol-containing 'mediators', but offer no explanation for this selectivity. It is more likely that eating extra Ins corrects a deficiency of an abundant Ins-containing cell constituent, probably phosphatidylinositol (PtdIns). Much of a cell's PtdIns is in ER membranes, and an increase in ER membrane synthesis, enhancing the ER's functional capacity, is often an important part of cell responses to ER stress. This review: (a) reinterprets historical information on Ins deficiency as describing a set of events involving a failure of cells adequately to adapt to ER stress; (b) proposes that in the conditions that respond to dietary Ins there is an overstretching of Ins reserves that limits the stressed ER's ability to make the 'extra' PtdIns needed for ER membrane expansion; and (c) suggests that eating Ins supplements increases the Ins supply to Ins-deficient and ER-stressed cells, allowing them to make more PtdIns and to expand the ER membrane system and sustain ER functions.

The effects of inositol supplementation on lipid profiles among patients with metabolic diseases: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Several studies have evaluated the effect of inositol supplementation on lipid profiles among population with metabolic diseases; however, the findings are controversial. This review of randomized controlled trials (RCTs) was performed to summarize the evidence of the effects of inositol supplementation on lipid profiles among population with metabolic diseases.

METHODS

Relevant RCTs studies were searched in Cochrane Library, EMBASE, MEDLINE, and Web of Science until October 2017. Two researchers assessed study eligibility, extracted data, and evaluated risk of bias of included primary studies, independently. To check for the heterogeneity among included studies Q-test and I₂ statistics were used. Data were pooled by using the random-effect model and standardized mean difference (SMD) was considered as summary of the effect size.

RESULTS

Overall, 14 RCTs were included into meta-analysis. Pooled results showed that inositol supplementation among patients with metabolic diseases significantly decreased triglycerides (SMD - 1.24; 95% CI, - 1.84, - 0.64; P < 0.001), total- (SMD - 1.09; 95% CI, - 1.83, - 0.55; P < 0.001), and LDL-cholesterol levels (SMD - 1.31; 95% CI, - 2.23, - 0.39; P = 0.005). There was no effect of inositol supplementation on HDL-cholesterol levels (SMD 0.20; 95% CI, - 0.27, 0.67; P = 0.40).

CONCLUSIONS

Inositol supplementation may result in reduction in triglycerides, total- and LDL-cholesterol levels, but did not affect HDL-cholesterol levels among patients with metabolic diseases. Additional prospective studies regarding the effect of inositol supplementation on lipid profiles in patients with metabolic diseases are necessary.

Inositols in Midlife

This review describes the mechanistic, animal, and clinical data related to the use of inositols in midlife. It covers studies related to the mechanism of action of myo-inositol and D-chiro-inositol and randomized controlled trials conducted in postmenopausal women with metabolic syndrome and supports these data with the results of in vitro and animal studies on inositol in nephropathy and other related conditions. Recent advances related to biochemistry, pharmaceutical science, and genetics are discussed. It concludes that inositols have a potential role to play in maintaining metabolic health in postmenopausal women.

Inositol in the MAnaGemENt of abdominal aortic aneurysm (IMAGEN): study protocol for a randomised controlled trial

Background

An abdominal aortic aneurysm (AAA) is a focal dilation of the abdominal aorta and is associated with a risk of fatal rupture. Experimental studies suggest that myo-inositol may exert beneficial effects on AAAs through favourable changes to biological pathways implicated in AAA pathology. The aim of the Inositol in the MAnaGemENt of abdominal aortic aneurysm (IMAGEN) trial is to assess if myo-inositol will reduce AAA growth.

Methods/design

IMAGEN is a multi-centre, prospective, parallel-group, randomised, double-blind, placebo-controlled trial. A total of 164 participants with an AAA measuring ≥ 30 mm will be randomised to either 2 g of myo-inositol or identical placebo twice daily for 12 months. The primary outcome measure will be AAA growth estimated by increase in total infrarenal aortic volume measured on computed tomographic scans. Secondary outcome measures will include AAA diameter assessed by computed tomography and ultrasound, AAA peak wall stress and peak wall rupture index, serum lipids, circulating AAA biomarkers, circulating RNAs and health-related quality of life. All analysis will be based on the intention-to-treat principle at the time of randomisation. All patients who meet the eligibility criteria, provide written informed consent and are enrolled in the study will be included in the primary analysis, regardless of adherence to dietary allocation.

Discussion

Currently, there is no known medical therapy to limit AAA progression. The IMAGEN trial will be the first randomised trial, to our knowledge, to assess the value of myo-inositol in limiting AAA growth.

Trial registration

Australian New Zealand Clinical Trials Registry, ACTRN12615001209583. Registered on 6 November 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2304-x) contains supplementary material, which is available to authorized users.

Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials

Myo-inositol (MI) supplementation in women with polycystic ovary syndrome (PCOS) has been evaluated over the last years. Many hormonal and reproductive impairments associated with this disorder seem relieved by the supplement. The objective of the meta-analysis was to assess the effects of MI alone or combined with d-chiro-inositol (DCI) on the endocrine and metabolic abnormalities of women with PCOS. Literature was retrieved from selected databases, MEDLINE, EMBASE, PubMed and Research Gate (up to November 2016). Only randomized controlled trials (RCTs) investigating the effects of MI alone or combined with DCI were reviewed. Nine RCTs involving 247 cases and 249 controls were included. Significant decreases in fasting insulin (SMD = -1.021 µU/mL, 95% CI: -1.791 to -0.251, P = 0.009) and homeostasis model assessment (HOMA) index (SMD = -0.585, 95% CI: -1.145 to -0.025, P = 0.041) were identified after MI supplementation. The trial sequential analysis of insulin meta-analysis illustrates that the cumulative z-curve crossed the monitoring boundary, providing firm evidence of the intervention effect. A slight trend toward a reduction of testosterone concentration by MI with respect to controls was found (SMD = -0.49, 95% CI: -1.072 to 0.092, P = 0.099), whereas androstenedione levels remained unaffected. Throughout a subgroup's meta-analysis, a significant increase in serum SHBG was observed only in those studies where MI was administered for at least 24 weeks (SMD = 0.425 nmol/L, 95% CI: 0.050-0.801, P = 0.026). These results highlight the beneficial effect of MI in improving the metabolic profile of women with PCOS, concomitantly reducing their hyperandrogenism.

Nutritional and Acquired Deficiencies in Inositol Bioavailability. Correlations with Metabolic Disorders

Communities eating a western-like diet, rich in fat, sugar and significantly deprived of fibers, share a relevant increased risk of both metabolic and cancerous diseases. Even more remarkable is that a low-fiber diet lacks some key components-as phytates and inositols-for which a mechanistic link has been clearly established in the pathogenesis of both cancer and metabolic illness. Reduced bioavailability of inositol in living organisms could arise from reduced food supply or from metabolism deregulation. Inositol deregulation has been found in a number of conditions mechanistically and epidemiologically associated to high-glucose diets or altered glucose metabolism. Indeed, high glucose levels hinder inositol availability by increasing its degradation and by inhibiting both myo-Ins biosynthesis and absorption. These underappreciated mechanisms may likely account for acquired, metabolic deficiency in inositol bioavailability.

Identification of differential metabolic characteristics between tumor and normal tissue from colorectal cancer patients by gas chromatography-mass spectrometry

Colorectal cancer (CRC) is one of the most common human malignancies and encompasses cancers of the colon and rectum. Although the gold-standard colonoscopy screening method is effective in detecting CRC, this method is invasive and can result in severe complications for patients. The purpose of this study was to determine differences in metabolites between CRC and matched adjacent nontumor tissues from CRC patients, to identify potential biomarkers that may be informative and developed screening methods. Metabolomic analysis was performed on clinically localized CRC tissue and matched adjacent nontumor tissue from 20 CRC patients. Unsupervised analysis, supervised analysis, univariate analysis and pathway analysis were used to identify potential metabolic biomarkers of CRC. The levels of 25 metabolites in CRC tissues were significantly altered compared with the matched adjacent nontumor tissues. Four metabolites (lactic acid, alanine, phosphate and aspartic acid) demonstrated good area under the curve of receiver-operator characteristic with acceptable sensitivities and specificities, indicating their potential as important biomarkers for CRC. Alterations of amino acid metabolism and enhanced glycolysis may be major factors in the development and progression of CRC. Lactic acid, alanine, phosphate, and aspartic acid could be effective diagnostic indicators for CRC.

Myo-inositol and melatonin in the menopausal transition

INTRODUCTION

The aim of the study was to evaluate the effects on serum insulin and serum thyroid profile of a dietary supplement, myo-inositol, given alone or in combination with melatonin to women during menopausal transition.

METHODS

Forty women aged 45-55 years and at least 6 months of amenorrhea were enrolled in this study. They were randomly assigned to two groups of 20 each. One group took myo-inositol (myo-Ins) (2 g twice a day) and the other group took 2 g/d myo-Ins plus 3 g/d melatonin before sleeping. At the beginning of the study and after 6 months, all women were evaluated for the following indices: waist circumference, body mass index, blood pressure, endometrial thickness, as well as serum concentrations of TSH, FT3, FT4 and insulin.

RESULTS

Both at baseline and at 6 months, the two groups were statistically similar for each of the considered indices. If percent changes (Δ%, 6 months over baseline) are contrasted in the two groups, serum TSH decreased in the myo-Ins group but increased in the latter, while serum insulin decreased in both groups.

CONCLUSIONS

The combination of myo-Ins plus melatonin seems to affect positively glucose metabolism, while myo-Ins only seems to improve thyroid function.

IMPA2 polymorphisms and risk of ischemic stroke in a northwest Han Chinese population

Genetic association analysis has suggested that IMPA2 is a susceptibility gene for ischemic stroke (IS). To explore the association between IMPA2 polymorphisms and the risk of IS in a Han Chinese population, candidate gene association was performed using data from a case-control study of 488 IS patients and 503 control subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association, and associations were evaluated under dominant, recessive, and additive genetic models using PLINK software. There was a statistically significant difference in the “TC” genotype frequency of the IMPA2 polymorphism rs589247, between cases and controls (50.0% vs. 45.3%). Under the dominant model, rs589247 was associated with an increased risk of IS (OR=1.32, 95%CI: 1.01-1.73; P=0.040). There were no other associations between any of the seven additional IMPA2 polymorphisms and IS risk. This study is the first to find a correlation between an IMPA2 polymorphism and IS risk in a northwest Han Chinese population. These results may help to elucidate the molecular pathogenesis of this disease, and could potentially be used to predict IS risk. However, further studies are still needed to validate this association in other populations and with larger sample sizes.

The effect of combined inositol supplementation on maternal metabolic profile in pregnancies complicated by metabolic syndrome and obesity

BACKGROUND

Myoinositol and D-chiroinositol improve insulin resistance in women with obesity and gestational diabetes and in postmenopausal women with metabolic syndrome. We previously reported that offspring born to hypertensive dams lacking endothelial nitric oxide synthase and fed a high-fat diet develop metabolic-like syndrome phenotype.

OBJECTIVE

The objective of the study was to investigate the effect of a mixture of myoinositol/D-chiroinositol supplementation during pregnancy on the maternal metabolic profile in pregnancies complicated by the metabolic-like syndrome and obesity using a pregnant mouse model.

STUDY DESIGN

Female heterozygous endothelial nitric oxide synthase(-/+) mice with moderate hypertension were placed on a high-fat diet for 4 weeks to induce a metabolic-like syndrome phenotype. Similarly, wild-type C57BL/6 mice were placed on a high-fat diet for 4 weeks to induce a murine obesity model. Mice were then bred with wild-type males. On gestational day 1, dams were randomly allocated to receive either a mixture of myoinositol/D-chiroinositol in water (7.2/0.18 mg/mL, respectively) or water as control (placebo). At term (gestational day 18), maternal weights, systolic blood pressure, and a glucose tolerance test were obtained. Dams were then killed; pups and placentas were weighed and maternal blood collected. Serum levels of metabolic biomarkers relevant to diabetes and obesity (ghrelin, gastric inhibitory peptide, glucagon-like peptide 1, glucagon, insulin, leptin, resistin) were measured by a multiplex enzyme-linked immunosorbent assay. Analysis was done comparing metabolic-like syndrome-myoinositol/D-chiroinositol-treated vs metabolic-like syndrome-nontreated mice and obese-myoinositol/D-chiroinositol-treated vs obese nontreated mice.

RESULTS

Mean systolic blood pressure was lower in metabolic-like syndrome pregnant mice treated with myoinositol/D-chiroinositol compared with placebo (P = .04), whereas there was no difference in systolic blood pressure between treated and placebo-treated obese pregnant mice. Pregnant metabolic-like syndrome mice treated with myoinositol/D-chiroinositol showed lower glucose values during the glucose tolerance test and in the area under the curve (myoinositol/D-chiroinositol: 17512.5 ± 3984.4 vs placebo: 29687.14 ± 8258.7; P = .003), but no differences were seen in the obese pregnant mice. Leptin serum levels were lower in the metabolic-like syndrome-myoinositol/D-chiroinositol-treated mice compared with the placebo group (myoinositol/D-chiroinositol: 16985 ± 976.4 pg/dL vs placebo: 24181.9 ± 3128.2 pg/dL, P = .045). No other differences were seen in any of the remaining serum metabolic biomarkers studied in metabolic-like syndrome and in obese pregnant mice. Maternal weight gain was not different in the pregnant metabolic-like syndrome dams, whereas it was lower in the obese myoinositol/D-chiroinositol-treated dams compared with the placebo group (myoinositol/D-chiroinositol: 10.9 ± 0.5 g vs 12.6 ± 0.6 g, P = .04). Fetal and placental weights did not differ between myoinositol/D-chiroinositol-treated and nontreated pregnant dams with metabolic-like syndrome and obesity.

CONCLUSION

Combined inositol treatment during pregnancy improves blood pressure, glucose levels at the glucose tolerance test, and leptin levels in pregnant dams with metabolic-like syndrome phenotype but not in obese pregnant dams. In addition, inositol treatment was associated with lower gestational weight gain in the obese but not in the metabolic-like syndrome pregnant dams.

Pharmacodynamics and pharmacokinetics of inositol(s) in health and disease

INTRODUCTION

Inositol and its derivatives comprise a huge field of biology. Myo-inositol is not only a prominent component of membrane-incorporated phosphatidylinositol, but participates in its free form, with its isomers or its phosphate derivatives, to a multitude of cellular processes, including ion channel permeability, metabolic homeostasis, mRNA export and translation, cytoskeleton remodeling, stress response.

AREAS COVERED

Bioavailability, safety, uptake and metabolism of inositol is discussed emphasizing the complexity of interconnected pathways leading to phosphoinositides, inositol phosphates and more complex molecules, like glycosyl-phosphatidylinositols.

EXPERT OPINION

Besides being a structural element, myo-inositol exerts unexpected functions, mostly unknown. However, several reports indicate that inositol plays a key role during phenotypic transitions and developmental phases. Furthermore, dysfunctions in the regulation of inositol metabolism have been implicated in several chronic diseases. Clinical trials using inositol in pharmacological doses provide amazing results in the management of gynecological diseases, respiratory stress syndrome, Alzheimer's disease, metabolic syndrome, and cancer, for which conventional treatments are disappointing. However, despite the widespread studies carried out to identify inositol-based effects, no comprehensive understanding of inositol-based mechanisms has been achieved. An integrated metabolomics-genomic study to identify the cellular fate of therapeutically administered myo-inositol and its genomic/enzymatic targets is urgently warranted.

Inositol's and other nutraceuticals' synergistic actions counteract insulin resistance in polycystic ovarian syndrome and metabolic syndrome: state-of-the-art and future perspectives

The incidence of metabolic syndrome (MetS), type II diabetes (T2D) and polycystic ovarian syndrome (PCOS) has been progressively increasing. Insulin resistance (InsR) seems to play a key role in a majority of phenotypes of these conditions, altering metabolic homeostasis, within muscle, liver, adipose and other tissues. Hyperinsulinemia is often associated with InsR and causes hormonal imbalances especially within ovaries and adrenals. Inositol is a polyalcohol, naturally occurring as nine stereoisomers, including D-chiro-inositol (DCI) and myo-inositol (MI), which have prominent roles in the metabolism of glucose and free fatty acids. MI and DCI have been classified as insulin-sensitizers and seem to adequately counteract several InsR-related metabolic alterations with a safe nutraceutical profile. Based on our analysis of selected studies that investigated MI and/or DCI, we conclude that supplementation with MI and/or DCI complement each other in their metabolic actions and act in synergy with other insulin sensitizing drugs and/or nutraceuticals. Nevertheless, considering the possible severe bias due to different methodologies across published studies, we conclude that there is a need for further studies on larger cohorts and with greater statistical power. These should further clarify outcomes and suitable therapeutic dosages of MI and DCI, possibly based on each patient's clinical status.

Inositol Hexaphosphate and Inositol Inhibit Colorectal Cancer Metastasis to the Liver in BALB/c Mice

Inositol hexaphosphate (IP6) and inositol (Ins), naturally occurring carbohydrates present in most mammals and plants, inhibit the growth of numerous cancers both in vitro and in vivo. In this study, we first examined the anti-metastatic effects of IP6 and Ins using a liver metastasis model of colorectal cancer (CRC) in BALB/c mice. CT-26 cells were injected into the splenic capsule of 48 BALB/c mice. The mice were then randomly divided into four groups: IP6, Ins, IP6 + Ins and normal saline control (n = 12 per group). IP6 and/or Ins (80 mg/kg each, 0.2 mL/day) were injected into the gastrointestinal tracts of the mice on the second day after surgery. All mice were sacrificed after 20 days, and the tumor inhibition rates were determined. The results demonstrated that the tumor weights of liver metastases and the tumor inhibition rates were reduced in the experimental groups compared to the control group and that treatment with the combination of IP6 and Ins resulted in greater inhibition of tumor growth than treatment with either compound alone. These findings suggest that IP6 and Ins prevent the development and metastatic progression of colorectal cancer to the liver in mice by altering expression of the extracellular matrix proteins collagen IV, fibronectin and laminin; the adhesion factor receptor integrin-β1; the proteolytic enzyme matrix metalloproteinase 9; and the angiogenic factors vascular endothelial growth factor, basic fibroblast growth factor, and transforming growth factor beta in the tumor metastasis microenvironment. In conclusion, IP6 and Ins inhibited the development and metastatic progression of colorectal cancer to the liver in BALB/c mice, and the effect of their combined application was significantly greater than the effect of either compound alone. This evidence supports further testing of the combined application of IP6 and Ins for the prevention of colorectal cancer metastasis to the liver in clinical studies.

Myo-Inositol Supplementation to Prevent Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common complication characterized by increased insulin resistance, and by increased risk for adverse pregnancy outcomes affecting both the mother and the fetus. International guidelines describe optimal ways to recognize it, and the recommended treatment of patients affected to reduce adverse outcomes. Improving insulin resistance could reduce incidence of GDM and its complications. Recently, a few trials have been published on the possible prevention of GDM. Inositol has been proposed as a food supplement that might reduce gestational diabetes incidence in high-risk pregnant women.

Effect of Myoinositol and Antioxidants on Sperm Quality in Men with Metabolic Syndrome

This prospective longitudinal study investigated the effects of a dietary supplement in patients affected by reduced sperm motility (asthenospermic males) with metabolic syndrome. The product tested was Andrositol®, which contains myoinositol (MI) as principal compound, in association with other molecules, and the parameters evaluated were semen characteristics as well as hormone and metabolic profiles. The inclusion criteria were subjects aged over 18 years, with asthenospermia and metabolic syndrome. The exclusion criteria were presence of cryptorchidism, varicocele, and prostatitis. For this study, 45 males who had such features were enrolled. Their selection was made according to the 2010 World Health Organization (WHO) criteria (5th Edition) for the Evaluation of Human Semen. Hormone and metabolic profiles and semen parameters were assessed at the beginning of the study and after three months of treatment with Andrositol. The differences between the values before and after the supplementation were found statistically significant. Andrositol normalized the metabolic profile of these patients, improving their insulin sensitivity. Moreover, testosterone levels were increased and the semen characteristics, such as sperm concentration, motility, and morphology, highly improved. In conclusion, the association of MI with other molecules (micronutrients and vitamins) could be an effective therapy for metabolic disorders, as well as hormonal and spermatic changes responsible for male infertility.

A Potential Therapeutic Role of Myoinositol in the Metabolic and Cardiovascular Profile of PCOS Iranian Women Aged between 30 and 40 Years

Introduction. Polycystic ovary syndrome (PCOS) is a common disorder in reproductive age. This pilot study investigated the effects of myoinositol (MI) treatment on metabolic and cardiovascular profile in PCOS women over 30 years of age. Methods. Between 2015 and 2016, 50 women with diagnosis of PCOS by the Rotterdam Criteria were included in the study. All women received MI 2 g plus 200 μg of folic acid (Inofolic, Health Parsian, Iran; twice daily) for 3 months. Baseline and 3-month serum samples were taken after an overnight fast to evaluate the insulin resistance index (HOMA-IR), fasting glucose, and the levels of triglyceride, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), homocysteine, systolic blood pressure, and diastolic blood pressure. Participants' weight was measured before and after treatment and body mass index (BMI) was calculated. Results. The data showed a significant improvement in the serum level of insulin sensitivity and a reduction of cholesterol, LDL, and homocysteine after three months of treatment. Furthermore, blood pressure was significantly reduced in the treated patients. Three participants became pregnant during treatment. Conclusion. Results showed that supplementation with MI and folic acid in PCOS patients over 30 years of age could decrease the risk of cardiovascular problems by normalizing the metabolic profile.

Inositols in the Treatment of Insulin-Mediated Diseases

A growing body of research is currently focused on the role of inositol isomers and in particular myo-inositol (MYO-INS) and D-chiroinositol (DCI) in the treatment of insulin resistance states. Both isomers have been shown to exert insulin-mimetic action and to lower postprandial glucose. Further, insulin resistance-related diseases were associated to derangements in inositol metabolism. Thus, the aim of this review is to provide current evidence on the potential benefits of inositol isomers (MYO-INS and DCI) in the treatment of disease associated to insulin resistance such as polycystic ovary syndrome (PCOS), gestational diabetes, and metabolic syndrome. Finally, molecular insights into inositol insulin-sensitizing effects will be covered focusing on the possible role of inositol glycans as insulin second messengers.

The Effectiveness of Myo-Inositol and D-Chiro Inositol Treatment in Type 2 Diabetes

Inositol has been used as a supplement in treating several pathologies such as PCOS, metabolic syndrome, and gestational diabetes. Both myo-inositol and its isomer d-chiro-inositol showed insulin mimetic effects in conditions of insulin resistance. Type 2 diabetes (T2DM) is a condition typically caused by insulin resistance. There is a lack of evidence of inositol use in T2DM. We evaluated the effectiveness and safety of myo-inositol and d-chiro-inositol treatment in T2DM. This was a pilot study involving a consecutive sample of patients with T2DM with suboptimal glycemic control (HbA1c 7.0-10.0%) already treated with glucose-lowering agents. Patients (23.1% males, mean age of 60.8 ± 11.7 years) took for three months a combination of myo-inositol (550 mg) and d-chiro-inositol (13.8 mg) orally twice a day as add-on supplement to their glucose-lowering drugs. Possible occurrence of side effects was investigated. After three months of treatment fasting blood glucose (192.6 ± 60.2 versus 160.9 ± 36.4; p = 0.02) and HbA1c levels (8.6 ± 0.9 versus 7.7 ± 0.9; p = 0.02) significantly decreased compared to baseline. There was no significant difference in blood pressure, lipid profile, and BMI levels. None of the participants reported side effects. In conclusion, a supplementation with a combination of myo- and d-chiro-inositol is an effective and safe strategy for improving glycemic control in T2DM.

Broad Spectrum Anticancer Activity of Myo-Inositol and Inositol Hexakisphosphate

Inositols (myo-inositol and inositol hexakisphosphate) exert a wide range of critical activities in both physiological and pathological settings. Deregulated inositol metabolism has been recorded in a number of diseases, including cancer, where inositol modulates different critical pathways. Inositols inhibit pRB phosphorylation, fostering the pRB/E2F complexes formation and blocking progression along the cell cycle. Inositols reduce PI3K levels, thus counteracting the activation of the PKC/RAS/ERK pathway downstream of PI3K activation. Upstream of that pathway, inositols disrupt the ligand interaction between FGF and its receptor as well as with the EGF-transduction processes involving IGF-II receptor and AP-1 complexes. Additionally, Akt activation is severely impaired upon inositol addition. Downregulation of both Akt and ERK leads consequently to NF-kB inhibition and reduced expression of inflammatory markers (COX-2 and PGE2). Remarkably, inositol-induced downregulation of presenilin-1 interferes with the epithelial-mesenchymal transition and reduces Wnt-activation, β-catenin translocation, Notch-1, N-cadherin, and SNAI1 release. Inositols interfere also with the cytoskeleton by upregulating Focal Adhesion Kinase and E-cadherin and decreasing Fascin and Cofilin, two main components of pseudopodia, leading hence to invasiveness impairment. This effect is reinforced by the inositol-induced inhibition on metalloproteinases and ROCK1/2 release. Overall, these effects enable inositols to remodel the cytoskeleton architecture.

Heritable IUGR and adult metabolic syndrome are reversible and associated with alterations in the metabolome following dietary supplementation of 1-carbon intermediates

Metabolic syndrome (MetS), following intrauterine growth restriction (IUGR), is epigenetically heritable. Recently, we abrogated the F2 adult phenotype with essential nutrient supplementation (ENS) of intermediates along the 1-carbon pathway. With the use of the same grandparental uterine artery ligation model, we profiled the F2 serum metabolome at weaning [postnatal day (d)21; n = 76] and adulthood (d160; n = 12) to test if MetS is preceded by alterations in the metabolome. Indicative of developmentally programmed MetS, adult F2, formerly IUGR rats, were obese (621 vs. 461 g; P < 0.0001), dyslipidemic (133 vs. 67 mg/dl; P < 0.001), and glucose intolerant (26 vs. 15 mg/kg/min; P < 0.01). Unbiased gas chromatography-mass spectrometry (GC-MS) profiling revealed 34 peaks corresponding to 12 nonredundant metabolites and 9 unknowns to be changing at weaning [false discovery rate (FDR) < 0.05]. Markers of later-in-life MetS included citric acid, glucosamine, myoinositol, and proline (P < 0.03). Hierarchical clustering revealed grouping by IUGR lineage and supplementation at d21 and d160. Weanlings grouped distinctly for ENS and IUGR by partial least-squares discriminate analysis (PLS-DA; P < 0.01), whereas paternal and maternal IUGR (IUGR(pat)/IUGR(mat), respectively) control-fed rats, destined for MetS, had a distinct metabolome at weaning (randomForest analysis; class error < 0.1) and adulthood (PLS-DA; P < 0.05). In sum, we have found that alterations in the metabolome accompany heritable IUGR, precede adult-onset MetS, and are partially amenable to dietary intervention.

Abnormalities in myo-inositol metabolism associated with type 2 diabetes in mice fed a high-fat diet: benefits of a dietary myo-inositol supplementation

We previously reported that a chronic supplementation with myo-inositol (MI) improved insulin sensitivity and reduced fat accretion in mice. We then tested the potency of such dietary intervention in the prevention of insulin resistance in C57BL/6 male mouse fed a high-fat diet (HFD). In addition, some abnormalities in inositol metabolism were reported to be associated with insulin resistance in several animal and human studies. We then investigated the presence of such anomalies (i.e. inosituria and an inositol intra-tissue depletion) in this diet-induced obesity (DIO) mouse model, as well as the potential benefit of a MI supplementation for inositol intra-tissue deficiency correction. HFD (60 % energy from fat) feeding was associated with inosituria and inositol intra-tissue depletion in the liver and kidneys. MI supplementation (0·58 mg/g per d) restored inositol pools in kidneys (partially) and liver (fully). HFD feeding for 4 months induced ectopic lipid redistribution to liver and muscles, fasting hyperglycaemia and hyperinsulinaemia, insulin resistance and obesity that were not prevented by MI supplementation, despite a significant improvement in insulin sensitivity parameter K insulin tolerance test and a reduction in white adipose tissue (WAT) mass ( - 17 %, P< 0·05). MI supplementation significantly reduced fatty acid synthase activity in epididymal WAT, which might explain its beneficial, but modest, effect on WAT accretion in HFD-fed mice. Finally, we found some abnormalities in inositol metabolism in association with a diabetic phenotype (i.e. insulin resistance and fasting hyperglycaemia) in a DIO mouse model. Dietary MI supplementation was efficient in the prevention of inositol intra-tissue depletion, but did not prevent insulin resistance or obesity efficiently in this mouse model.

Effects of a new flavonoid and Myo-inositol supplement on some biomarkers of cardiovascular risk in postmenopausal women: a randomized trial

Background and Aim. Cardiovascular risk is increased in women with menopause and metabolic syndrome. Aim of this study was to test the effect of a new supplement formula, combining cocoa polyphenols, myo-inositol, and soy isoflavones, on some biomarkers of cardiovascular risk in postmenopausal women with metabolic syndrome. Methods and Results. A total of 60 women were enrolled and randomly assigned (n = 30 per group) to receive the supplement (NRT: 30 mg of cocoa polyphenols, 80 mg of soy isoflavones, and 2 gr of myo-inositol), or placebo for 6 months. The study protocol included three visits (baseline, 6, and 12 months) for the evaluation of glucose, triglycerides, and HDL-cholesterol (HDL-C), adiponectin, visfatin, resistin, and bone-specific alkaline phosphatase (bone-ALP). At 6 months, a significant difference between NRT and placebo was found for glucose (96 ± 7 versus 108 ± 10 mg/dL), triglycerides (145 ± 14 versus 165 ± 18 mg/dL), visfatin (2.8 ± 0.8 versus 3.7 ± 1.1 ng/mL), resistin (27 ± 7 versus 32 ± 8 µg/L), and b-ALP (19 ± 7 versus 15 ± 5 µg/mL). No difference in HDL-C concentrations nor in adiponectin levels between groups was reported at 6 months. Conclusions. The supplement used in this study improves most of the biomarkers linked to metabolic syndrome. This Trial is registered with NCT01400724.

Potential role and therapeutic interests of myo-inositol in metabolic diseases

Several inositol isomers and in particular myo-inositol (MI) and D-chiro-inositol (DCI), were shown to possess insulin-mimetic properties and to be efficient in lowering post-prandial blood glucose. In addition, abnormalities in inositol metabolism are associated with insulin resistance and with long term microvascular complications of diabetes, supporting a role of inositol or its derivatives in glucose metabolism. The aim of this review is to focus on the potential benefits of a dietary supplement of myo-inositol, by far the most common inositol isomer in foodstuffs, in human disorders associated with insulin resistance (polycystic ovary syndrome, gestational diabetes mellitus or metabolic syndrome) or in prevention or treatment of some diabetic complications (neuropathy, nephropathy, cataract). The relevance of such a nutritional strategy will be discussed for each context on the basis of the clinical and/or animal studies. The dietary sources of myo-inositol and its metabolism from its dietary uptake to its renal excretion will be also covered in this review. Finally, the actual insights into inositol insulin-sensitizing effects will be addressed and in particular the possible role of inositol glycans as insulin second messengers.