Low urinary chiro-inositol excretion in non-insulin-dependent diabetes mellitus

Characteristics of individuals who developed type 2 diabetes from prediabetes despite undergoing interventions, and evaluation of the performance of urinary myo-inositol as a risk factor for developing diabetes

AIMS/INTRODUCTION

The aim of this study was to clarify the characteristics of individuals with prediabetes who developed type 2 diabetes despite undergoing interventions, and to evaluate the performance of urinary myo-inositol (UMI) as a noninvasive indicator for the risk of developing diabetes.

MATERIALS AND METHODS

A total of 51 individuals with prediabetes who underwent a 75-g oral glucose tolerance test, ΔUMI (the difference in the UMI : creatinine ratio between before and 120 min after 75-g glucose loading), fasting plasma glucose, insulin, hemoglobin A1c, noninvasive testing (age, body mass index, blood pressure) and general blood tests were measured at baseline, and underwent dietary/exercise guidance for 8 years were studied.

RESULTS

A total of 31 participants developed diabetes in 8 years. At baseline, the group that developed diabetes was characterized by high ΔUMI, hemoglobin A1c, fasting plasma glucose and low high-density lipoprotein cholesterol, and insulinogenic index (I.I.). I.I and ΔUMI showed a higher correlation than fasting plasma glucose and hemoglobin A1c. Regarding diabetes onset within 8 years, Cox regression analysis of diabetes onset showed the baseline ΔUMI is an independent predictor, adjusted for the result of not only noninvasive markers, but also that of noninvasive and general blood markers. The log-rank test showed that all glycemic indicators were significantly associated with diabetes onset.

CONCLUSION

Participants who developed type 2 diabetes from prediabetes despite undergoing interventions were characterized by high glycemic control markers and low I.I. As noninvasive measurement of ΔUMI is associated with I.I. and diabetes onset, it could be a useful indicator for identifying individuals with a high risk of diabetes onset.

Anti-Alzheimer Potential of a New (+)-Pinitol Glycoside Isolated from Tamarindus indica Pulp: In Vivo and In Silico Evaluations

Tamarindus indica Linn (tamarind, F. Leguminosae) is one of the most widely consumed edible fruits in the world. Phytochemical investigation of tamarind pulp n-butanol fraction yielded one new (+)-pinitol glycoside compound 1 (25% w/w), and 1D, 2D NMR, and HRESIMS investigation were used to confirm the new compound's structure. (+)-Pinitol glycoside showed anti-Alzheimer potential that was confirmed in prophylactic and treatment groups by decreasing time for the T-maze test; decreased TAO, brain and serum AChE, MDA, tau protein levels, and β amyloid peptide protein levels; and increasing GPX, SOD levels, and in vivo regression of the neurodegenerative features of Alzheimer's dementia in an aluminum-intoxicated rat model. The reported molecular targets for human Alzheimer's disease were then used in a network pharmacology investigation to examine their complex interactions and identify the key targets in the disease pathogenesis. An in silico-based analysis (molecular docking, binding free energy calculation (ΔG_Binding), and molecular dynamics simulation) was performed to identify the potential targets for compound 1. The findings of this study may lead to the development of dietary supplements for the treatment of Alzheimer's disease.

Polycystic Ovary Syndrome as Metabolic Disease: New Insights on Insulin Resistance

Polycystic ovary syndrome (PCOS) is a very frequent disease that affects reproductive ability and menstrual regularity. Other than the criteria established at the Rotterdam consensus, in these last few years a new issue, insulin resistance, has been found frequently, and at a very high grade, in patients with PCOS. Insulin resistance occurs for several factors, such as overweight and obesity, but it is now clear that it occurs in patients with PCOS with normal weight, thus supporting the hypothesis that insulin resistance is independent of body weight. Evidence shows that a complex pathophysiological situation occurs that impairs post-receptor insulin signalling, especially in patients with PCOS and familial diabetes. In addition, patients with PCOS have a high incidence of non-alcoholic fatty liver disease related to the hyperinsulinaemia. This narrative review focuses on the recent new insights about insulin resistance in patients with PCOS, to better understand the metabolic impairment accounting for most of the clinical signs/symptoms of PCOS.

The Role of Inositols in the Hyperandrogenic Phenotypes of PCOS: A Re-Reading of Larner’s Results

Polycystic ovarian syndrome (PCOS) is the most common endocrinological disorder in women, in which, besides chronic anovulation/oligomenorrhea and ovarian cysts, hyperandrogenism plays a critical role in a large fraction of subjects. Inositol isomers—myo-Inositol and D-Chiro-Inositol—have recently been pharmacologically effective in managing many PCOS symptoms while rescuing ovarian fertility. However, some disappointing clinical results prompted the reconsideration of their specific biological functions. Surprisingly, D-Chiro-Ins stimulates androgen synthesis and decreases the ovarian estrogen pathway; on the contrary, myo-Ins activates FSH response and aromatase activity, finally mitigating ovarian hyperandrogenism. However, when the two isomers are given in association—according to the physiological ratio of 40:1—patients could benefit from myo-Ins enhanced FSH and estrogen responsiveness, while taking advantage of the insulin-sensitizing effects displayed mostly by D-Chiro-Ins. We need not postulate insulin resistance to explain PCOS pathogenesis, given that insulin hypersensitivity is likely a shared feature of PCOS ovaries. Indeed, even in the presence of physiological insulin stimulation, the PCOS ovary synthesizes D-Chiro-Ins four times more than that measured in control theca cells. The increased D-Chiro-Ins within the ovary is detrimental in preserving steroidogenic control, and this failure can easily explain why treatment strategies based upon high D-Chiro-Ins have been recognized as poorly effective. Within this perspective, two factors emerge as major determinants in PCOS: hyperandrogenism and reduced aromatase expression. Therefore, PCOS could no longer be considered a disease only due to increased androgen synthesis without considering the contemporary downregulation of aromatase and FSH receptors. Furthermore, these findings suggest that inositols can be specifically effective only for those PCOS phenotypes featured by hyperandrogenism.

Neurobiology and Applications of Inositol in Psychiatry: A Narrative Review

Inositol is a natural sugar-like compound, commonly present in many plants and foods. It is involved in several biochemical pathways, most of them controlling vital cellular mechanisms, such as cell development, signaling and nuclear processes, metabolic and endocrine modulation, cell growth, signal transduction, etc. In this narrative review, we focused on the role of inositol in human brain physiology and pathology, with the aim of providing an update on both potential applications and current limits in its use in psychiatric disorders. Overall, imaging and biomolecular studies have shown the role of inositol levels in the pathogenesis of mood disorders. However, when administered as monotherapy or in addition to conventional drugs, inositol did not seem to influence clinical outcomes in both mood and psychotic disorders. Conversely, more encouraging results have emerged for the treatment of panic disorders. We concluded that, despite its multifaceted neurobiological activities and some positive findings, to date, data on the efficacy of inositol in the treatment of psychiatric disorders are still controversial, partly due to the heterogeneity of supporting studies. Therefore, systematic use of inositol in routine clinical practice cannot be recommended yet, although further basic and translational research should be encouraged.

Antenatal dietary supplementation with myo-inositol for preventing gestational diabetes

BACKGROUND

Gestational diabetes with onset or first recognition during pregnancy is an increasing problem worldwide. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. Myo-inositol is one of the intracellular mediators of the insulin signal and correlates with insulin sensitivity in type 2 diabetes. The potential beneficial effect of improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes. This is an update of a review first published in 2015.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, WHO ICTRP (17 March 2022) and the reference lists of retrieved studies.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) including cluster-RCTs and conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes in pregnant women. We included studies that compared any dose of myo-inositol, alone or in a combination preparation, with no treatment, placebo or another intervention. Quasi-randomised and cross-over trials were not eligible. We excluded women with pre-existing type 1 or type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, assessed risk of bias and extracted the data. We checked the data for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included seven RCTs (one conducted in Ireland, six conducted in Italy) reporting on 1319 women who were 10 weeks to 24 weeks pregnant at the start of the studies. The studies had relatively small sample sizes and the overall risk of bias was low. For the primary maternal outcomes, meta-analysis showed that myo-inositol may reduce the incidence of gestational diabetes (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.31 to 0.90; 6 studies, 1140 women) and hypertensive disorders of pregnancy (RR 0.34, 95% CI 0.19 to 0.61; 5 studies, 1052 women). However, the certainty of the evidence was low to very low. For the primary neonatal outcomes, only one study measured the risk of a large-for-gestational-age infant and found myo-inositol was associated with both appreciable benefit and harm (RR 1.40, 95% CI 0.65 to 3.02; 1 study, 234 infants; low-certainty evidence). None of the included studies reported on the other primary neonatal outcomes (perinatal mortality, mortality or morbidity composite). For the secondary maternal outcomes, we are unclear about the effect of myo-inositol on weight gain during pregnancy (mean difference (MD) -0.25 kilogram (kg), 95% CI -1.26 to 0.75 kg; 4 studies, 831 women) and perineal trauma (RR 4.0, 95% CI 0.45 to 35.25; 1 study, 234 women) because the evidence was assessed as being very low-certainty. Further, myo-inositol may result in little to no difference in caesarean section (RR 0.91, 95% CI 0.77 to 1.07; 4 studies, 829 women; low-certainty evidence). None of the included studies reported on the other secondary maternal outcomes (postnatal depression and the development of subsequent type 2 diabetes mellitus). For the secondary neonatal outcomes, meta-analysis showed no neonatal hypoglycaemia (RR 3.07, 95% CI 0.90 to 10.52; 4 studies; 671 infants; very low-certainty evidence). However, myo-inositol may be associated with a reduction in the incidence of preterm birth (RR 0.35, 95% CI 0.17 to 0.70; 4 studies; 829 infants). There were insufficient data for a number of maternal and neonatal secondary outcomes, and no data were reported for any of the long-term childhood or adulthood outcomes, or for health service utilisation outcomes.

AUTHORS' CONCLUSIONS

Evidence from seven studies shows that antenatal dietary supplementation with myo-inositol during pregnancy may reduce the incidence of gestational diabetes, hypertensive disorders of pregnancy and preterm birth. Limited data suggest that supplementation with myo-inositol may not reduce the risk of a large-for-gestational-age infant.  The current evidence is based on small studies that were not powered to detect differences in outcomes such as perinatal mortality and serious infant morbidity. Six of the included studies were conducted in Italy and one in Ireland, which raises concerns about the lack of generalisability to other settings. There is evidence of inconsistency among doses of myo-inositol, the timing of administration and study population. As a result, we downgraded the certainty of the evidence for many outcomes to low or very low certainty. Further studies for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors. Myo-inositol at different doses, frequency and timing of administration, should be compared with placebo, diet and exercise, and pharmacological interventions. Long-term follow-up should be considered and outcomes should include potential harms, including adverse effects.

D-Pinitol Ameliorated Osteoporosis via Elevating D-chiro-Inositol Level in Ovariectomized Mice

A natural sugar alcohol, D-pinitol, has been reported to be a potential compound for osteoporosis treatment via inhibiting osteoclastgenesis. However, research on the effects of pinitol on osteoporosis in vivo is still limited. The present study investigated the protective effects of pinitol on ovariectomized mice and attempted to elucidate this mechanism in vivo. Four-week-old female ovariectomized ICR mice were employed as a postmenopausal osteoporosis model and treated with pinitol or estradiol (E2) for 7 wk. Thereafter, serum calcium content, phosphorus content, tartrate-resistant acid phosphatase (TRAcP) and bone-specific alkaline phosphatase activity (BALP) were measured. Bilateral femurs were isolated, and bone marrow protein was collected through centrifuge. Dry femurs were weighed, while femur length, cellular bones, and bone mineral content were measured. D-chiro-Inositol (DCI) and myo-inositol (MI) content in serum and bone marrow was measured by GC-MS. At the end of experiment, the serum BALP and TRAcP activities of the OVX mice were suppressed significantly by treatment with either pinitol or E2. Femur weight, cellular bone rate, Ca and P content were improved by pinitol or E2. The DCI content of the serum of OVX decreased significantly, although it recovered to some extent after pinitol treatment. Pinitol significantly increased the ratio of DCI to MI in serum or bone marrow protein in the observed OVX mice. Besides, pinitol had no significant effects on osteoblast viability and differentiation. The present results showed that continuous pinitol intake exerts potent anti-osteoporosis activity via elevating DCI content in serum and bone marrow in OVX mice.

Urinary Metabolic Profiling in Volunteers Undergoing Malaria Challenge in Gabon

The interaction of malaria parasites with their human host is extensively studied, yet only few studies reported how P. falciparum infection affects urinary metabolite profiles and how this is associated with immunity. We present a longitudinal study of the urinary metabolic profiles of twenty healthy Africans with lifelong exposure to malaria and five malaria-naïve Europeans, who were all challenged with direct venous inoculation of live P. falciparum sporozoïtes (PfSPZ) and followed up until they developed symptoms or became thick blood smear positive (TBS). Urine samples were collected before and at 2, 5, 9 and 11 days post challenge and were analysed. Upon infection, all Europeans became TBS positive, while Africans showed either a delay in time to parasitaemia or controlled infection. Our metabolic data showed that Europeans and Africans had distinct alterations in metabolite patterns, with changes mostly seen on days 5 and 9 post PfSPZ infection, and more prominently in Europeans. Within the African group, the levels of formate, urea, trimethylamine, threonine, choline, myo-inositol and acetate were significantly higher in TBS positive whereas the levels of pyruvate, 3-methylhistidine and dimethylglycine were significantly lower in individuals who remained TBS negative. Notably, before inoculation with PfSPZ, a group of metabolites including phenylacetylglutamine can potentially be used to predict parasitaemia control among Africans. Taken together, this study highlights the difference in urinary metabolic changes in response to malaria infection as a consequence of lifelong exposure to malaria and that change detectable before challenge might predict the control of parasitaemia in malaria-endemic areas.

Putative Complementary Compounds to Counteract Insulin-Resistance in PCOS Patients

Polycystic ovary syndrome (PCOS) is the most frequent endocrine-metabolic disorder among women at reproductive age. The diagnosis is based on the presence of at least two out of three criteria of the Rotterdam criteria (2003). In the last decades, the dysmetabolic aspect of insulin resistance and compensatory hyperinsulinemia have been taken into account as the additional key features in the etiopathology of PCOS, and they have been widely studied. Since PCOS is a complex and multifactorial syndrome with different clinical manifestations, it is difficult to find the gold standard treatment. Therefore, a great variety of integrative treatments have been reported to counteract insulin resistance. PCOS patients need a tailored therapeutic strategy, according to the patient’s BMI, the presence or absence of familiar predisposition to diabetes, and the patient’s desire to achieve pregnancy or not. The present review analyzes and discloses the main clinical insight of such complementary substances.

D-Pinitol-Active Natural Product from Carob with Notable Insulin Regulation

Carob is one of the major food trees for peoples of the Mediterranean basin, but it has also been traditionally used for medicinal purposes. Carob contains many nutrients and active natural products, and D-Pinitol is clearly one of the most important of these. D-Pinitol has been reported in dozens of scientific publications and its very diverse medicinal properties are still being studied. Presently, more than thirty medicinal activities of D-Pinitol have been reported. Among these, many publications have reported the strong activities of D-Pinitol as a natural antidiabetic and insulin regulator, but also as an active anti-Alzheimer, anticancer, antioxidant, and anti-inflammatory, and is also immune- and hepato-protective. In this review, we will present a brief introduction of the nutritional and medicinal importance of Carob, both traditionally and as found by modern research. In the introduction, we will present Carob’s major active natural products. The structures of inositols will be presented with a brief literature summary of their medicinal activities, with special attention to those inositols in Carob, as well as D-Pinitol’s chemical structure and its medicinal and other properties. D-Pinitol antidiabetic and insulin regulation activities will be extensively presented, including its proposed mechanism of action. Finally, a discussion followed by the conclusions and future vision will summarize this article.

Inositols in the ovaries: activities and potential therapeutic applications

INTRODUCTION

Myo-inositol (MI) and d-chiro-inositol (DCI) play a key role in ovarian physiology, as they are second messengers of insulin and gonadotropins. Ex-vivo and in-vitro experiments demonstrate that both isomers are deeply involved in steroid biosynthesis, and that reduced MI-to-DCI ratios are associated with pathological imbalance of sex hormones.

AREAS COVERED

This expert opinion provides an overview of the physiological distribution of MI and DCI in the ovarian tissues, and a thorough insight of their involvement into ovarian steroidogenesis. Insulin resistance and compensatory hyperinsulinemia dramatically reduce the MI-to-DCI ratio in the ovaries, leading to gynecological disorders characterized by hyperandrogenism, altered menstrual cycle and infertility.

EXPERT OPINION

Available evidence indicates that MI and DCI have very specific physiological roles and, seemingly, physiological MI-to-DCI ratios in the ovaries are crucial to maintain the correct homeostasis of steroids. Inositol treatments should be evaluated on the patients' specific conditions and needs, as long-term supplementation of high doses of DCI may cause detrimental effects on the ovarian functionality. In addition, the effects of inositol therapy on the different PCOS phenotypes should be further investigated in order to better tailor the supplementation.

PCOS and Assisted Reproduction Technique: Role and Relevance of Inositols

Polycystic ovary syndrome is an endocrine disorder often characterized by insulin resistance and hyperinsulinemia, especially in overweight/obese women. Among insulin sensitizers, the positive role of inositols has been increasingly established in recent years. The action of inositols not only concerns the metabolic parameters of these patients, but also the hormonal profile, resulting in beneficial effects on ovarian function. For this reason, many studies have tried to recognize their role in PCOS infertile women who underwent in vitro fertilization (IVF) procedures.

Inositols: From Established Knowledge to Novel Approaches

Myo-inositol (myo-Ins) and D-chiro-inositol (D-chiro-Ins) are natural compounds involved in many biological pathways. Since the discovery of their involvement in endocrine signal transduction, myo-Ins and D-chiro-Ins supplementation has contributed to clinical approaches in ameliorating many gynecological and endocrinological diseases. Currently both myo-Ins and D-chiro-Ins are well-tolerated, effective alternative candidates to the classical insulin sensitizers, and are useful treatments in preventing and treating metabolic and reproductive disorders such as polycystic ovary syndrome (PCOS), gestational diabetes mellitus (GDM), and male fertility disturbances, like sperm abnormalities. Moreover, besides metabolic activity, myo-Ins and D-chiro-Ins deeply influence steroidogenesis, regulating the pools of androgens and estrogens, likely in opposite ways. Given the complexity of inositol-related mechanisms of action, many of their beneficial effects are still under scrutiny. Therefore, continuing research aims to discover new emerging roles and mechanisms that can allow clinicians to tailor inositol therapy and to use it in other medical areas, hitherto unexplored. The present paper outlines the established evidence on inositols and updates on recent research, namely concerning D-chiro-Ins involvement into steroidogenesis. In particular, D-chiro-Ins mediates insulin-induced testosterone biosynthesis from ovarian thecal cells and directly affects synthesis of estrogens by modulating the expression of the aromatase enzyme. Ovaries, as well as other organs and tissues, are characterized by a specific ratio of myo-Ins to D-chiro-Ins, which ensures their healthy state and proper functionality. Altered inositol ratios may account for pathological conditions, causing an imbalance in sex hormones. Such situations usually occur in association with medical conditions, such as PCOS, or as a consequence of some pharmacological treatments. Based on the physiological role of inositols and the pathological implications of altered myo-Ins to D-chiro-Ins ratios, inositol therapy may be designed with two different aims: (1) restoring the inositol physiological ratio; (2) altering the ratio in a controlled way to achieve specific effects.

Urinary metabolomic profiling reveals difference between two traditional Chinese medicine subtypes of coronary heart disease

The World Health Organization has shown that coronary heart disease (CHD) is a more common cause of death than cancer. In traditional Chinese medicine (TCM), CHD is classified as a form of thoracic obstruction that can be divided in different subtypes including Qi stagnation with blood stasis (QS) and Qi deficiency with blood stasis (QD). Different treatment strategies are used based on this subtyping. Owing to the lack of scientific markers in the diagnosis of these subtypes, subjective judgments made by clinicians have limited the objective manner for utility of TCM in the treatment of CHD. Untargeted (UHPLC-QTOF-MS) and targeted (UHPLC-MS/MS) metabolomics approaches were employed to search significantly different metabolites related to the QS or QD subtypes of CHD with angina pectoris in this study. A total of 42 metabolites were obtained in the untargeted metabolomics analysis and 34 amino acids were detected in the targeted metabolomics analysis. In total, 16 metabolites were found significantly different among different groups. The results showed distinct metabolic profiles of urine samples not only between CHD patients and healthy controls, but also between the two subtypes of CHD. Pathway analysis of the significantly varied metabolites revealed that there were subtype-related differences in the activity of pathways. Therefore, urinary metabolomics can reveal the pathological changes of CHD in different subtypes, make the diagnosis of CHD in different subtypes in an objective manner and comprehensive and contribute to personalized treatment by providing scientific evidence.

Myoinositol plus α-lactalbumin supplementation, insulin resistance and birth outcomes in women with gestational diabetes mellitus: a randomized, controlled study

To verify whether myo-inositol plus α-lactalbumin may reduce insulin resistance and excessive fetal growth in women with gestational diabetes mellitus. In a 12-month period, 120 women with a diagnosis of gestational diabetes mellitus were consecutively enrolled with an allocation of 1:1 in each group and randomly treated with myo-inositol plus α-lactalbumin plus folic acid (treated group) or folic acid (control group) for 2 months. Primary outcome was the variation of insulin resistance through the study evaluated by HOMA-IR. Secondary outcome was the evaluation, through the study, of fetal growth by ultrasound measurements of abdominal circumference centiles and estimated fat thickness. Some clinical outcomes were also considered. After 2 months, in the treated group, a significant reduction in insulin resistance (HOMA values 3.1 ± 1.4 vs 6.1 ± 3.4, p = 0.0002) and fetal growth was shown (Abdominal circumference centiles 54.9 ± 23.5 vs 67.5 ± 22.6, P = 0.006). Among clinical outcomes, a significant decrease in the rate of women who needed insulin (6.7% vs 20.3%, p = 0.03) and of pre-term birth (0 vs 15.2%, p = 0.007) was evidenced. A combination of myo-inositol and α-lactalbumin may reduce insulin resistance and excessive fetal growth.

Clinical trial registration: ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT 03763669, first posted date 04/12/2018; last posted date December 06/12/2018.

Metabolomics analysis reveals altered metabolites in lean compared with obese adolescents and additional metabolic shifts associated with hyperinsulinaemia and insulin resistance in obese adolescents: a cross-sectional study

INTRODUCTION

Hyperinsulinaemia and insulin resistance (IR) are strongly associated with obesity and are forerunners of type 2 diabetes. Little is known about metabolic alterations separately associated with obesity, hyperinsulinaemia/IR and impaired glucose tolerance (IGT) in adolescents.

OBJECTIVES

To identify metabolic alterations associated with obesity, hyperinsulinaemia/IR and hyperinsulinaemia/IR combined with IGT in obese adolescents.

METHODS

81 adolescents were stratified into four groups based on body mass index (lean vs. obese), insulin responses (normal insulin (NI) vs. high insulin (HI)) and glucose responses (normal glucose tolerance (NGT) vs. IGT) after an oral glucose tolerance test (OGTT). The groups comprised: (1) healthy lean with NI and NGT, (2) obese with NI and NGT, (3) obese with HI and NGT, and (4) obese with HI and IGT. Targeted nuclear magnetic resonance-based metabolomics analysis was performed on fasting and seven post-OGTT plasma samples, followed by univariate and multivariate statistical analyses.

RESULTS

Two groups of metabolites were identified: (1) Metabolites associated with insulin response level: adolescents with HI (groups 3-4) had higher concentrations of branched-chain amino acids and tyrosine, and lower concentrations of serine, glycine, myo-inositol and dimethylsulfone, than adolescents with NI (groups 1-2). (2) Metabolites associated with obesity status: obese adolescents (groups 2-4) had higher concentrations of acetylcarnitine, alanine, pyruvate and glutamate, and lower concentrations of acetate, than lean adolescents (group 1).

CONCLUSIONS

Obesity is associated with shifts in fat and energy metabolism. Hyperinsulinaemia/IR in obese adolescents is also associated with increased branched-chain and aromatic amino acids.

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.

Analytical Methods for Determination of Phytic Acid and Other Inositol Phosphates: A Review

From the early precipitation-based techniques, introduced more than a century ago, to the latest development of enzymatic bio- and nano-sensor applications, the analysis of phytic acid and/or other inositol phosphates has never been a straightforward analytical task. Due to the biomedical importance, such as antinutritional, antioxidant and anticancer effects, several types of methodologies were investigated over the years to develop a reliable determination of these intriguing analytes in many types of biological samples; from various foodstuffs to living cell organisms. The main aim of the present work was to critically overview the development of the most relevant analytical principles, separation and detection methods that have been applied in order to overcome the difficulties with specific chemical properties of inositol phosphates, their interferences, absence of characteristic signal (e.g., absorbance), and strong binding interactions with (multivalent) metals and other biological molecules present in the sample matrix. A systematical and chronological review of the applied methodology and the detection system is given, ranging from the very beginnings of the classical gravimetric and titrimetric analysis, through the potentiometric titrations, chromatographic and electrophoretic separation techniques, to the use of spectroscopic methods and of the recently reported fluorescence and voltammetric bio- and nano-sensors.

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.

Discovery of Gut Bacteria Specific to Alzheimer's Associated Diseases is a Clue to Understanding Disease Etiology: Meta-Analysis of Population-Based Data on Human Gut Metagenomics and Metabolomics

Alzheimer's disease (AD)-associated sequence (ADAS) of cultured fecal bacteria was discovered in human gut targeted screening. This study provides important information to expand our current understanding of the structure/activity relationship of ADAS and putative inhibitors/activators that are potentially involved in ADAS appearance/disappearance. The NCBI database analysis revealed that ADAS presents at a large proportion in American Indian Oklahoman (C&A) with a high prevalence of obesity/diabetes and in colorectal cancer (CRC) patients from the US and China. An Oklahoman non-native group (NNI) showed no ADAS. Comparison of two large US populations reveals that ADAS is more frequent in individuals aged ≥66 and in females. Prevalence and levels of fecal metabolites are altered in the C&A and CRC groups versus controls. Biogenic amines (histamine, tryptamine, tyramine, phenylethylamine, cadaverine, putrescine, agmatine, spermidine) that present in food and are produced by gut microbiota are significantly higher in C&A (e.g., histamine/histidine 95-fold) versus NNI (histamine/histidine 16-fold). The majority of these bio-amines are cytotoxic at concentrations found in food. Inositol phosphate signaling implicated in AD is altered in C&A and CRC. Tryptamine stimulated accumulation of inositol phosphate. The seizure-eliciting tryptamine induced cytoplasmic vacuolization and vesiculation with cell fragmentation. Present additions of ADAS-carriers at different ages including infants led to an ADAS-comprising human sample size of 2,830 from 27 studies from four continents (North America, Australia, Asia, Europe). Levels of food-derived monoamine oxidase inhibitors and anti-bacterial compounds, the potential modulators of ADAS-bacteria growth and biogenic amine production, were altered in C&A versus NNI. ADAS is attributable to potentially modifiable risk factors of AD associated diseases.

Altered Ovarian Inositol Ratios May Account for Pathological Steroidogenesis in PCOS

The presence of abnormal ovarian ratios of myo-inositol (MI) to D-chiro-inositol (DCI) is a recurrent feature in PCOS. Available evidence suggests that MI and DCI may modulate steroid biosynthesis, likely in an opposite manner. Specifically, MI seems to induce estrogen production, while DCI has a role in the synthesis of androgens. Elevated insulin levels, generally associated with PCOS, alter the physiological MI/DCI ratio, increasing MI-to-DCI conversion through activation of a specific epimerase enzyme. DCI directly increases testosterone biosynthesis in thecal cells and reduces its conversion to estradiol by downregulating aromatase enzyme in granulosa cells. This manuscript reviews the literature that supports the connection between altered MI/DCI ratios and pathological steroidogenesis observed in PCOS women. Furthermore, it discusses the application of inositol-based treatment protocols in managing PCOS symptoms and improving the quality of patients' life.

Plasma and urinary inositol isomer profiles measured by UHPLC-MS/MS reveal differences in scyllo-inositol levels between non-pregnant and pregnant women

Previous studies support that myo- and D-chiro-inositol isomers are promising bioactives for the treatment of women with polycystic ovary syndrome and for lowering the risk of gestational diabetes mellitus in pregnant women, whereas scyllo-inositol may have some benefits for neurological disorders (e.g., Alzheimer's disease). Though potentially useful to better understand inositol isomer metabolism and study their role in health and disease, routine analysis of inositol isomers in plasma and urine with a single analytical method is not yet feasible due to the lack of a suitable analytical assay. To address this, we developed and validated a robust ultra-high-performance-liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the quantification of inositol isomers in plasma and urine. This method resolves seven inositol isomers with accurate quantification of total chiro- (D and L enantiomers), myo-, and scyllo-inositols and is semi-quantitative for neo-inositol. For urine and plasma myo-inositol, the method repeatability and intermediate reproducibility were below 6% and 8%, respectively. Then, for both chiro- and scyllo-inositols, repeatability and intermediate reproducibility were below 10% and 14%, respectively. A pilot study was carried out to quantify and compare the pattern of inositol isomers in urine and plasma of non-pregnant and pregnant women and showed for the first time that urinary myo- and scyllo-inositol concentrations were significantly higher for women in the third trimester of pregnancy compared with non-pregnant women. These findings warrant further research to understand the biological significance of the observed differences in inositol profiles and suggest a potential role of scyllo-inositol.Graphical abstract Plasma and urinary inositol isomer profiles measured by UHPLC-MS/MS reveal differences in scyllo-inositol levels between non-pregnant and pregnant women.

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.

Myo-Inositol's Role in Assisted Reproductive Technology: Evidence for Improving the Quality of Oocytes and Embryos in Patients With Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common causes of subfertility, and it is characterized by hormonal dysregulation like insulin resistance. Various measures have been taken in the past to overcome this insulin resistance to improve fertility treatment outcomes. The current paper aims to review and compare the existing studies and literature to assess the impact of myo-inositol (MI) on oocyte and embryo quality in assisted reproductive technology (ARTs). We thoroughly searched the PubMed and Google Scholar databases by using the keywords "PCOS, polycystic ovarian syndrome, inositol, oocyte quality, embryo quality, assisted conception, ART, IVF, and in vitro fertilization." Nine articles were finalized for review in this paper. Many of the reviewed studies have shown a trend toward the improvement of embryo quality in women with PCOS after MI supplementation; however, there is a lack of statistically significant evidence to support the use of MI in enhancing the quality of oocyte and/or embryo. Clear evidence regarding the role of MI in enhancing the quality of oocyte and embryo in PCOS is limited. A well-controlled, large, randomized controlled trial is required to definitively accept or refute its role.

Effect of probiotics on the intestinal microbiota of hemodialysis patients: a randomized trial

BACKGROUND

Intestinal dysbiosis contributes to the progression of renal failure and cardiovascular diseases in patients with chronic kidney disease. Probiotics is a promising intervention to improving intestinal dysbiosis. A double-blind clinical trial to investigate the ability of probiotics to modulate gut microbiota compositions in patients receiving hemodialysis (HD) was undertaken.

METHODS

Fifty HD patients were enrolled and randomized, receiving either probiotics or placebo for 6 months. The responses to the interventions on gut microbiome, serum and fecal metabolome, serum albumin and endotoxin, endothelial activation markers and inflammatory markers were assessed.

RESULTS

Totally, 22 in the probiotics group (11 males; 14 non-diabetic) and 23 in the placebo group (13 males; 17 non-diabetic) completed the study. Compared to that in the placebo group, probiotics did not significantly alter species diversity of the fecal microbiome. Probiotics did, however, restore the community composition, with particular significance in non-diabetic HD patients (P = 0.007 by Adonis analysis). Specifically, according to the results of linear discriminate analysis effect size, probiotics raised the proportions of family Bacteroidaceae and Enterococcaceae, and reduced Ruminococcaceae, Halomonadaceae, Peptostreptococcaceae, Clostridiales Family XIII. Incertae Sedis and Erysipelotrichaceae in non-diabetic HD patients. Additionally, probiotics reduced the abundances of several uremic retention solutes in serum or feces, including indole-3-acetic acid-O-glucuronide, 3-guanidinopropionic acid, and 1-methylinosine (P < 0.05). In the probiotic arm, no significant changes were observed in other secondary outcomes.

CONCLUSIONS

Taken together, outcomes from this study suggest that probiotics do have benefits on improving intestinal imbalances and lowering exposure to several uremic toxins in HD patients.

Simple and non-invasive screening method for diabetes based on myoinositol levels in urine samples collected at home

OBJECTIVE

To establish a simple screening method for diabetes based on myoinositol (MI) in urine samples collected at home.

RESEARCH DESIGN AND METHODS

Initially, we evaluated the stability of urinary MI (UMI) at room temperature (RT; 25°C) and 37°C in 10 outpatients with type 2 diabetes. We then enrolled 115 volunteers without a current or history of diabetes. In all subjects, glucose intolerance was diagnosed by 75 g oral glucose tolerance test (75gOGTT). To assess the association between UMI or urine glucose (UG) and plasma glucose (PG), urine samples were also collected at 0 and 2 hours during 75gOGTT. All the subjects collected urine samples at home before and 2 hours after consuming the commercially available test meal. UMI levels at wake-up time (UMI_wake-up), before (UMI_premeal) and 2 hours after the test meal (UMI_{2h-postprandial}) were measured using an enzymatic method. ΔUMI was defined as UMI_{2h-postprandial} minus UMI_premeal.

RESULTS

Differing from UG, UMI was stable at RT and 37°C. UMI was increased linearly along with an increase in PG, and no threshold for UMI was observed. UMI was closely associated with blood glucose parameters obtained from a 75gOGTT and hemoglobin A1c (HbA1c) at hospital after adjustment for age, sex, body mass index and serum creatinine. UMI_wake-up, UMI_premeal, UMI_{2h-postprandial} and ΔUMI at home were higher in diabetic subjects than non-diabetic subjects even after the above adjustment. Receiver operating characteristics curve (ROC) analyses revealed that for the screening of diabetes, the area under the curve for ROC for UMI_{2h-postprandial} and ΔUMI (0.83 and 0.82, respectively) were not inferior to that for HbA1c ≥48 mmol/mol, which is the American Diabetes Association (ADA) criteria for diabetes.

CONCLUSIONS

MI measurement in urine samples collected at home before and after the meal would be a simple, non-invasive and valuable screening method for diabetes.

Regulation of Inositol Biosynthesis: Balancing Health and Pathophysiology

Inositol is the precursor for all inositol compounds and is essential for viability of eukaryotic cells. Numerous cellular processes and signaling functions are dependent on inositol compounds, and perturbation of their synthesis leads to a wide range of human diseases. Although considerable research has been directed at understanding the function of inositol compounds, especially phosphoinositides and inositol phosphates, a focus on regulatory and homeostatic mechanisms controlling inositol biosynthesis has been largely neglected. Consequently, little is known about how synthesis of inositol is regulated in human cells. Identifying physiological regulators of inositol synthesis and elucidating the molecular mechanisms that regulate inositol synthesis will contribute fundamental insight into cellular processes that are mediated by inositol compounds and will provide a foundation to understand numerous disease processes that result from perturbation of inositol homeostasis. In addition, elucidating the mechanisms of action of inositol-depleting drugs may suggest new strategies for the design of second-generation pharmaceuticals to treat psychiatric disorders and other illnesses.

Combined Inositol Hexakisphosphate and Inositol Supplement Consumption Improves Serum Alpha-Amylase Activity and Hematological Parameters in Streptozotocin-Induced Type 2 Diabetic Rats

This study evaluated the effect of combined inositol hexakisphosphate (IP6) and inositol supplement on organ weight, intestinal ATPase activities, complete blood count, and serum analytes in streptozotocin (STZ)-induced type 2 diabetic rats. High-fat diet and a single intraperitoneal injection of streptozotocin (35 mg/kg body weight) were used to induce type 2 diabetes mellitus in Sprague–Dawley rats. The diabetic groups were then treated with either combined IP6 and inositol supplement or glibenclamide for four weeks. Organ weights, intestinal ATPase activities, complete blood count, serum α-amylase, total protein, albumin, and globulin content were determined. Pancreatic weight was significantly reduced while relative kidney and liver weights were elevated in the group treated with combined IP6 and inositol supplement compared to the nondiabetic control. Serum α-amylase activity for the glibenclamide and combination treated groups was significantly improved compared to that of the untreated diabetic group. Red cell distribution width percentage was significantly lower in the combination treated group compared to that in the untreated diabetic group, while intestinal ATPase activities were unaffected by the treatment regime. Combined IP6 and inositol supplement consumption may protect people with diabetes from increased risk of cardiovascular diseases due to the supplement's ability to maintain red cell distribution width percentage towards the normal control group.

Comparison of myo-inositol and metformin on glycemic control, lipid profiles, and gene expression related to insulin and lipid metabolism in women with polycystic ovary syndrome: a randomized controlled clinical trial

This investigation was conducted to evaluate comparison of myo-inositol and metformin on glycemic control, lipid profiles, and gene expression related to insulin and lipid metabolism in women with polycystic ovary syndrome (PCOS). This randomized controlled trial was conducted on 53 women with PCOS, aged 18-40 years old. Subjects were randomly allocated into two groups to take either myo-inositol (n = 26) or metformin (n = 27) for 12 weeks. Myo-inositol supplementation, compared with metformin, significantly reduced fasting plasma glucose (FPG) (β -5.12 mg/dL; 95% CI, -8.09, -2.16; p=.001), serum insulin levels (β -1.49 µIU/mL; 95% CI, -2.28, -0.70; p<.001), homeostasis model of assessment-insulin resistance (β -0.36; 95% CI, -0.55, -0.17; p<.001), serum triglycerides (β 12.42 mg/dL; 95% CI, -20.47, -4.37; p=.003) and VLDL-cholesterol levels (β -2.48 mg/dL; 95% CI, -4.09, -0.87; p=.003), and significantly increased the quantitative insulin sensitivity check index (β 0.006; 95% CI, 0.002, 0.01; p=.006) compared with metformin. Moreover, myo-inositol supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (p=.002) compared with metformin. Overall, taking myo-inositol, compared with metformin, for 12 weeks by women with PCOS had beneficial effects on glycemic control, triglycerides and VLDL-cholesterol levels, and gene expression of PPAR-γ.

Vascular and metabolic profiles in offspring born to pregnant mice with metabolic syndrome treated with inositols

BACKGROUND

Inositols (INOs) supplementation during pregnancy, specifically the combination of myo-inositol (MI) and D-chiro-inositol (DCI), has been reported to improve vascular parameters in women with gestational diabetes mellitus. We demonstrated previously that offspring born to pregnant mice lacking the endothelial nitric oxide synthase (eNOS+/-) gene have hypertension (HTN) as adults and, when fed a high-fat diet (HFD), develop a metabolic syndrome (MS) phenotype.

OBJECTIVE

Our aim was to evaluate whether INOs treatment in pregnancy complicated by MS improves the vascular and metabolic profile in mice offspring programmed in utero to develop HTN and MS.

MATERIALS AND METHODS

Heterozygous eNOS+/- mice fed an HFD manifest a MS phenotype. Female eNOS+/- mice with MS were bred with a wild-type (WT) male. On gestational day 1, pregnant females were randomly allocated to receive either a mixture of INOs (MI/DCI: 7.2/0.18 mg/mL) or water as placebo until delivery. The female offspring obtained were genotyped and categorized as: WT (genetically normal, with eNOS gene) and eNOS+/- offspring (genetically modified, heterozygous for eNOS gene). Both offspring developed in an abnormal uterine environment due to maternal MS. At 9-10 weeks of age, the offspring underwent a glucose tolerance test (GTT) and systolic blood pressure (SBP) measurement. The mice were then sacrificed, and the carotid arteries were isolated for evaluation of vascular responses. Responses to phenylephrine (PE), in the presence and absence of a nonspecific nitric oxide inhibitor (N-nitro-L-arginine methyl ester [L-NAME]), the vasodilator acetylcholine (ACh), and sodium nitroprusside (SNP) were assessed.

RESULTS

The GTT showed lower glucose levels in both eNOS+/-INOs (P = .03) and WT-INOs (P = .05) offspring born to MS dams on INOs supplementation compared to offspring born to untreated dams. SBP was higher in eNOS+/- offspring compared to WT (169 ± 7 vs 142 ± 9 mm Hg, respectively, P = .04) and INOs treatment decreased SBP in WT-INOs (110 ± 10 mm Hg, P = .01) but not in eNOS+/-INOs offspring. Maximal (%Max) contractile response to PE was higher in eNOS+/- offspring born to MS dams and was decreased in those born to MS dams treated with INOs (%Max, eNOS+/-, 123 ± 7 vs eNOS+/-INOs, 82 ± 11 mm Hg, P = .007). No differences were seen in PE contractile responses in WT offspring born to MS dams treated or not treated with INOs (WT, 92 ± 4 vs WT-INOs, 75 ± 7). The L-NAME response was decreased in eNOS+/-INOs and WT-INOs offspring compared to untreated ones. The ACh vasorelaxation was impaired in eNOS+/- and WT offspring born to MS dams, and maternal INOs treatment improved offspring vascular relaxation in both offspring (P = .01 and P = .03, respectively). No differences were seen in response to SNP.

CONCLUSION

Inositols supplementation improved glucose tolerance, SBP, and vascular responses in adult eNOS+/- and WT offspring born to dams with MS. Interestingly, WT born to MS dams show an altered vascular profile similar to eNOS+/- offspring and exhibit an improved response to INOs treatment. Our findings suggest that the benefits of INOs treatment are more pronounced in offspring exposed to environmental factors in utero, and less likely in those due to genetic factors.

Osteocyte viability and bone density in cadmium chloride-induced osteoporosis ameliorated with Pilostigma thonningii stem bark-extracted D-3-O-methy-chiroinositol

BACKGROUND

This study examined the ameliorative effect of D-3-O-methyl-chiroinositol, isolated from the stem bark of Piliostigma thonningii, on cadmium chloride-induced osteoporosis in male Wistar rats.

METHODS

Thirty-six rats were assigned to three treatment groups (n = 12). Group A (2 mL distilled water), group B: (2.5 mg/kg b.w. CdCl2) and group C: (2.5 mg/kg b.w. CdCl2 and D-3-O-methyl-chiroinositol 2 mg/kg b.w.). Bone ash, calcium, phosphate, magnesium, and zinc content, as well as bone histological changes were determined at the end of months 1, 2, and 3.

RESULTS

There were significant differences (P ≤ 0.05) in the weight of the cervical, tibia, and femoral bones in all groups. The serum concentration of CdCl2 was significantly different across the three groups with time. There was significant variation (P < 0.005) in the mean bone ash across groups. The concentration of OH-proline was significantly different (P < 0.0001) across groups. There were significant differences (P < 0.0001) in bone calcium, magnesium, zinc, and phosphorus concentrations. Histology revealed high levels of bone mineralisation in the CdCl2-treated group, indicative of osteoporosis with hypertrophied osteocytes, while the femur of Wistar rats treated with D-3-O-methyl-chiroinositol showed bone trabeculae and viable osteocytes.

CONCLUSION

The study concluded that D-3-O-methyl-chiroinositol extract from Piliostigma thionningii stem bark ameliorated cadmium chloride-induced osteoporosis in male Wistar rats.

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.

Serum Ethanolamine Plasmalogen and Urine Myo-Inositol as Cognitive Decline Markers

Recent studies have suggested that metabolic disorders, particularly type 2 diabetes mellitus (T2DM), and dementia, including Alzheimer's disease (AD), were linked at the clinical and molecular levels. Brain insulin deficiency and resistance may be key events in AD pathology mechanistically linking AD to T2DM. Ethanolamine plasmalogens (PlsEtns) are abundant in the brain and play essential roles in neuronal function and myelin formation. As such, PlsEtn deficiency may be pathologically relevant in some neurodegenerative disorders such as AD. Decreased brain PlsEtn associated with dementia may reflect serum PlsEtn deficiency. We hypothesized that myo-inositol plays a role in myelin formation through its facilitation of PlsEtn biosynthesis. Excessive urinary myo-inositol (UMI) loss would likely result in PlsEtn deficiency potentially leading to demyelinating diseases such as dementia. Accordingly, measurement of both serum PlsEtn and baseline UMI excretion could improve the detection of cognitive impairment (CI) in a more specific and reliable manner. To verify our hypothesis, we conducted a clinical observational study of memory clinic outpatients (MCO) and cognitively normal elderly (NE) for nearly 4.5years. We demonstrated that serum PlsEtn concentration associated with UMI excretion was useful for predicting advancing dementia in patients with mild CI. Because hyperglycemia and associated insulin resistance might be a leading cause of increased baseline UMI excretion, serum PlsEtn quantitation would be useful in detecting CI among the elderly with hyperglycemia. Our findings suggest that myo-inositol is a novel candidate molecule linking T2DM to AD.

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.

Management of women with PCOS using myo-inositol and folic acid. New clinical data and review of the literature

Introduction The use of 2 × 2000 mg myo-inositol +2 × 200 μg folic acid per day is a safe and promising tool in the effective improvement of symptoms and infertility for patients with polycystic ovary syndrome (PCOS). In addition, PCOS is one of the pathological factors involved in the failure of in vitro fertilization (IVF). Typically, PCOS patients suffer of poor quality oocytes. Patients and methods In an open, prospective, non-blinded, non-comparative observational study, 3602 infertile women used myo-inositol and folic acid between 2 and 3 months in a dosage of 2 × 2000 mg myo-inositol +2 × 200 μg folic acid per day. In a subgroup of 32 patients, hormonal values for testosterone, free testosterone and progesterone were analyzed before and after 12 weeks of treatment. The mean time of use was 10.2 weeks. In the second part of this trial it was investigated if the combination of myo-inositol + folic acid was able to improve the oocyte quality, the ratio between follicles and retrieved oocytes, the fertilization rate and the embryo quality in PCOS patients undergoing IVF treatments. Twenty-nine patients with PCOS, underwent IVF protocols for infertility treatment and were randomized prospectively into two groups. Group A (placebo) with 15 patients and group B (4000 mg myo-inositol +400 μg folic acid per day) with 14 patients were evaluated. The patients of group B used 2 months' myo-inositol + folic acid before starting the IVF protocol. For statistically analyses Student's t-test was performed. Results Seventy percent of the women had a restored ovulation, and 545 pregnancies were observed. This means a pregnancy rate of 15.1% of all the myo-inositol and folic acid users. In 19 cases a concomitant medication with clomiphene or dexamethasone was used. One twin pregnancy was documented. Testosterone levels changed from 96.6 ng/mL to 43.3 ng/mL and progesterone from 2.1 ng/mL to 12.3 ng/mL in the mean after 12 weeks of treatment (p < 0.05) Student's t-test. No relevant side effects were present among the patients. The women in the IVF treatment the group A showed a higher number of retrieved oocytes than group B. Nevertheless, the ratio follicle/retrieved oocyte was clearly better in the myo-inositol group (= group B). Out of the 233 oocytes collected in the myo-inositol group, 136 where fertilized whereas only 128 out of 300 oocytes were fertilized in the placebo group. With regards to the oocytes quality, better data were obtained in the myo-inositol group. More metaphase II and I oocytes were retrieved in relation to the total number of oocytes, when compared with the placebo group. Also, more embryos of grade I quality were observed in the myo-inositol group than in the placebo group. The duration of stimulation was 9.7 days (±3.3) in the myo-inositol group and 11.2 (±1.8) days in the placebo group and the number of used follicle-stimulating hormone (FSH) units was lower in the myo-inositol group in comparison to the placebo group: 1850 FSH units (mean) versus 1850 units (mean). Discussion Myo-inositol has proven to be a new treatment option for patients with PCOS and infertility. The achieved pregnancy rates are at least in an equivalent or even superior range than those reported using metformin as an insulin sensitizer. No moderate to severe side effects were observed when myo-inositol was used at a dosage of 4000 mg per day. In addition, our evidence suggests that a myo-inositol therapy in women with PCOS results in better fertilization rates and a clear trend to a better embryo quality. As by the same way the number of retrieved oocytes was smaller in the myo-inositol group, the risk of a hyperstimulation syndrome in these patients can be reduced. Therefore, myo-inositol also represents an improvement in IVF protocols for patients with PCOS.

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.

Polycystic Ovary Syndrome: Insights into the Therapeutic Approach with Inositols

Polycystic ovary syndrome (PCOS) is characterized by hormonal abnormalities that cause menstrual irregularity and reduce ovulation rate and fertility, associated to insulin resistance. Myo-inositol (cis-1,2,3,5-trans-4,6-cyclohexanehexol, MI) and D-chiro-inositol (cis-1,2,4-trans-3,5,6-cyclohexanehexol, DCI) represent promising treatments for PCOS, having shown some therapeutic benefits without substantial side effects. Because the use of inositols for treating PCOS is widespread, a deep understanding of this treatment option is needed, both in terms of potential mechanisms and efficacy. This review summarizes the current knowledge on the biological effects of MI and DCI and the results obtained from relevant intervention studies with inositols in PCOS. Based on the published results, both MI and DCI represent potential valid therapeutic approaches for the treatment of insulin resistance and its associated metabolic and reproductive disorders, such as those occurring in women affected by PCOS. Furthermore, the combination MI/DCI seems also effective and might be even superior to either inositol species alone. However, based on available data, a particular MI:DCI ratio to be administered to PCOS patients cannot be established. Further studies are then necessary to understand the real contents of MI or DCI uptaken by the ovary following oral administration in order to identify optimal doses and/or combination ratios.

Inositol and human reproduction. From cellular metabolism to clinical use

Inositol is an organic compound of high biological importance that is widely distributed in nature. It belongs to the sugar family and is mainly represented by its two dominant stereoisomers: myo-inositol and D-chiro-inositol that are found in the organism in the physiological serum ratio 40:1. Inositol and its derivatives are important components of the structural phospholipids of the cell membranes and are precursors of the second messengers of many metabolic pathways. A high concentration of myoinositol is found in the follicular fluid and in semen. Inositol deficiency and the impairment of the inositol-dependent pathways may play an important role in the pathogenesis of insulin resistance and hypothyroidism. The results of the research also point out the potential beneficial role of inositol supplementation in polycystic ovarian syndrome and in the context of assisted reproduction technologies and in vitro fertilization. The main aim of the article is to overview the major inositol-dependent metabolic pathways and to discuss its importance for reproduction.

The Inositol-3-Phosphate Synthase Biosynthetic Enzyme Has Distinct Catalytic and Metabolic Roles

Inositol levels, maintained by the biosynthetic enzyme inositol-3-phosphate synthase (Ino1), are altered in a range of disorders, including bipolar disorder and Alzheimer's disease. To date, most inositol studies have focused on the molecular and cellular effects of inositol depletion without considering Ino1 levels. Here we employ a simple eukaryote, Dictyostelium discoideum, to demonstrate distinct effects of loss of Ino1 and inositol depletion. We show that loss of Ino1 results in an inositol auxotrophy that can be rescued only partially by exogenous inositol. Removal of inositol supplementation from the ino1(-) mutant resulted in a rapid 56% reduction in inositol levels, triggering the induction of autophagy, reduced cytokinesis, and substrate adhesion. Inositol depletion also caused a dramatic generalized decrease in phosphoinositide levels that was rescued by inositol supplementation. However, loss of Ino1 triggered broad metabolic changes consistent with the induction of a catabolic state that was not rescued by inositol supplementation. These data suggest a metabolic role for Ino1 that is independent of inositol biosynthesis. To characterize this role, an Ino1 binding partner containing SEL1L1 domains (Q54IX5) and having homology to mammalian macromolecular complex adaptor proteins was identified. Our findings therefore identify a new role for Ino1, independent of inositol biosynthesis, with broad effects on cell metabolism.

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.

The "Other" Inositols and Their Phosphates: Synthesis, Biology, and Medicine (with Recent Advances in myo-Inositol Chemistry)

Cell signaling via inositol phosphates, in particular via the second messenger myo-inositol 1,4,5-trisphosphate, and phosphoinositides comprises a huge field of biology. Of the nine 1,2,3,4,5,6-cyclohexanehexol isomers, myo-inositol is pre-eminent, with "other" inositols (cis-, epi-, allo-, muco-, neo-, L-chiro-, D-chiro-, and scyllo-) and derivatives rarer or thought not to exist in nature. However, neo- and d-chiro-inositol hexakisphosphates were recently revealed in both terrestrial and aquatic ecosystems, thus highlighting the paucity of knowledge of the origins and potential biological functions of such stereoisomers, a prevalent group of environmental organic phosphates, and their parent inositols. Some "other" inositols are medically relevant, for example, scyllo-inositol (neurodegenerative diseases) and d-chiro-inositol (diabetes). It is timely to consider exploration of the roles and applications of the "other" isomers and their derivatives, likely by exploiting techniques now well developed for the myo series.

Putative Key Role of Inositol Messengers in Endothelial Cells in Preeclampsia

Immunological alterations, endothelial dysfunction, and insulin resistance characterize preeclampsia. Endothelial cells hold the key role in the pathogenesis of this disease. The signaling pathways mediating these biological abnormalities converge on PKB/Akt, an intracellular kinase regulating cell survival, proliferation, and metabolism. Inositol second messengers are involved in metabolic and cell signaling pathways and are highly expressed during preeclampsia. Intracellular action of these molecules is deeply affected by zinc, manganese, and calcium. To evaluate the pathophysiological significance, we present the response of the intracellular pathways of inositol phosphoglycans involved in cellular metabolism and propose a link with the disease.

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.

Prospective Randomized Study on the Influence of Myoinositol in PCOS Women Undergoing IVF in the Improvement of Oocyte Quality, Fertilization Rate, and Embryo Quality

Polycystic ovarian syndrome (PCOS) is one of the pathological factors involved in the failure of in vitro fertilization (IvF). The aim of the present study was to investigate if the combination of myoinositol + folic acid was able to improve the oocyte quality, the ratio between follicles and retrieved oocytes, the fertilization rate, and the embryo quality in PCOS patients undergoing IvF treatments. 29 patients with PCOS underwent IvF protocols for infertility treatment and were randomized prospectively into two groups. Group A (placebo) with 15 patients and group B (4000 mg myoinositol + 400 μg folic acid per day) with 14 patients. The patients of group B used for two months myoinositol + folic acid before starting the IvF protocol and data were obtained concerning number of follicles, number of oocytes, quality of oocytes, fertilization rates, and embryo quality in both groups. The ratio follicle/retrieved oocyte was better in the myoinositol group (= group B). Out of the 233 oocytes collected in the myoinositol group 136 were fertilized, whereas only 128 out of 300 oocytes in the placebo group were fertilized. More metaphase II and I oocytes were retrieved in relation to the total amount of oocytes in the myoinositol. More embryos of grade I quality were obtained in the myoinositol. The duration of stimulation was 9,7 days (±3,3) in the myoinositol group and 11,2 (±1,8) days in the placebo group and the number of used FSH units was lower in the myoinositol group: 1750 FSH units (mean) versus 1850 units (mean). Our evidence suggests that myoinositol therapy in women with PCOS results in better fertilization rates and a clear trend to a better embryo quality. As the number of retrieved oocytes was smaller in the myoinositol group, the risk of hyper stimulation syndrome can be reduced in these patients.

Effects of Inositol(s) in Women with PCOS: A Systematic Review of Randomized Controlled Trials

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, with complex etiology and pathophysiology, which remains poorly understood. It affects about 5-10% of women of reproductive age who typically suffer from obesity, hyperandrogenism, ovarian dysfunction, and menstrual irregularity. Indeed, PCOS is the most common cause of anovulatory infertility in industrialized nations, and it is associated with insulin resistance, type 2 diabetes mellitus, and increased cardiovascular risk. Although insulin resistance is not included as a criterion for diagnosis, it is a critical pathological condition of PCOS. The purpose of this systematic review is the analysis of recent randomized clinical trials of inositol(s) in PCOS, in particular myo- and D-chiro-inositol, in order to better elucidate their physiological involvement in PCOS and potential therapeutic use, alone and in conjunction with assisted reproductive technologies, in the clinical treatment of women with PCOS.

Antenatal dietary supplementation with myo-inositol in women during pregnancy for preventing gestational diabetes

BACKGROUND

Gestational diabetes, glucose intolerance with onset or first recognition during pregnancy, is a rising problem worldwide. Both non-pharmacological and pharmacological approaches to the prevention of gestational diabetes have been, and continue to be explored. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. It is one of the intracellular mediators of the insulin signal and correlated with insulin sensitivity in type 2 diabetes. The potential beneficial effect on improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, WHO ICTRP (2 November 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

We sought published and unpublished randomised controlled trials, including conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes mellitus (GDM). Quasi-randomised and cross-over trials were not eligible for inclusion, but cluster designs were eligible. Participants in the trials were pregnant women. Women with pre-existing type 1 or type 2 diabetes were excluded. Trials that compared the administration of any dose of myo-inositol, alone or in a combination preparation were eligible for inclusion. Trials that used no treatment, placebo or another intervention as the comparator were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, risk of bias and extracted the data. Data were checked for accuracy.

MAIN RESULTS

We included four randomised controlled trials (all conducted in Italy) reporting on 567 women who were less than 11 weeks' to 24 weeks' pregnant at the start of the trials. The trials had small sample sizes and one trial only reported an interim analysis. Two trials were open-label. The overall risk of bias was unclear.For the mother, supplementation with myo-inositol was associated with a reduction in the incidence of gestational diabetes compared with control (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.29 to 0.64; three trials; n = 502 women). Using GRADE methods this evidence was assessed as low with downgrading due to unclear risk of bias for allocation concealment in two of the included trials and lack of generalisability of findings. For women who received myo-inositol supplementation, the incidence of GDM ranged from 8% to 18%; for women in the control group, the incidence of GDM was 28%, using International Association of Diabetes and Pregnancy Study Groups Consensus Panel 2010 criteria to diagnose GDM.Two trials reported on hypertensive disorders of pregnancy, a primary maternal outcome of this review. There was no clear difference in risk of hypertensive disorders of pregnancy between the myo-inositol and control groups (average RR 0.43, 95% CI 0.02 to 8.41; two trials; n = 398 women; Tau(2) = 3.23; I(2) = 69%). Using GRADE methods, this evidence was assessed as very low, with downgrading due to wide confidence intervals with very low event rates, a small sample size, and lack of blinding and unclear allocation concealment methods, and a lack of generalisability. For women who received myo-inositol the risk of hypertensive disorders of pregnancy ranged from 0% to 33%; for women in the control group the risk was 4%.For the infant, none of the included trials reported on the primary neonatal outcomes of this systematic review (large-for-gestational age, perinatal mortality, mortality or morbidity composite).In terms of this review's secondary outcomes, there was no clear difference in the risk of caesarean section between the myo-inositol and control groups (RR 0.95, 95% CI 0.76 to 1.19; two trials; n = 398 women). Using GRADE methods, this evidence was assessed as low, with downgrading due to unclear risk of bias in one trial and lack of generalisability. For women who received myo-inositol supplementation, the risk of having a caesarean section ranged from 34% to 54%; for women in the control group the was 45%. There were no maternal adverse effects of therapy in the two trials that reported on this outcome (the other two trials did not report this outcome).Two trials found no clear difference in the risk of macrosomia between infants whose mothers received myo-inositol supplementation compared with controls (average RR 0.35, 95% CI 0.02 to 6.37; two trials; n = 398 infants;Tau(2) = 3.33; I(2) = 73%). Similarly, there was no clear difference between groups in terms of neonatal hypoglycaemia (RR 0.36, 95% CI 0.01 to 8.66) or shoulder dystocia (average RR 2.33, 95% CI 0.12 to 44.30, Tau(2) = 3.24; I(2) = 72%).There was a lack of data available for a large number of maternal and neonatal secondary outcomes, and no data for any of the long-term childhood or adulthood outcomes, or for health service cost outcomes.

AUTHORS' CONCLUSIONS

Evidence from four trials of antenatal dietary supplementation with myo-inositol during pregnancy shows a potential benefit for reducing the incidence of gestational diabetes. No data were reported for any of this review's primary neonatal outcomes. There were very little outcome data for the majority of this review's secondary outcomes. There is no clear evidence of a difference for macrosomia when compared with control.The current evidence is based on small trials that are not powered to detect differences in outcomes including perinatal mortality and serious infant morbidity. All of the included studies were conducted in Italy which raises concerns about the lack of generalisability of the evidence to other settings. There is evidence of inconsistency and indirectness and as a result, many of the judgements on the quality of the evidence were downgraded to low or very low quality (GRADEpro Guideline Development Tool).Further trials for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors and use of myo-inositol (different doses, frequency and timing of administration) in comparison with placebo, diet and exercise or pharmacological interventions. Outcomes should include potential harms including adverse effects.