Free Insulin Research Articles

Amino Acid Compound 2 (AAC2) Treatment Counteracts Insulin-Induced Synaptic Gene Expression and Seizure-Related Mortality in a Mouse Model of Alzheimer’s Disease

Diabetes is a major risk factor for Alzheimer’s disease (AD). Amino acid compound 2 (AAC2) improves glycemic and cognitive functions in diabetic mouse models through mechanisms distinct from insulin. Our goal was to compare the effects of AAC2, insulin, and their nanofiber-forming combination on early asymptomatic AD pathogenesis in APP/PS1 mice. Insulin, but not AAC2 or the combination treatment (administered intraperitoneally every 48 h for 120 days), increased seizure-related mortality, altered the brain fat-to-lean mass ratio, and improved specific cognitive functions in APP/PS1 mice. NanoString and pathway analysis of cerebral gene expression revealed dysregulated synaptic mechanisms, with upregulation of Bdnf and downregulation of Slc1a6 in insulin-treated mice, correlating with insulin-induced seizures. In contrast, AAC2 promoted the expression of Syn2 and Syp synaptic genes, preserved brain composition, and improved survival. The combination of AAC2 and insulin counteracted free insulin’s effects. None of the treatments influenced canonical amyloidogenic pathways. This study highlights AAC2’s potential in regulating synaptic gene expression in AD and insulin-induced contexts related to seizure activity.

Injectable Gelled Multiple Emulsion for Glucose-Responsive Insulin Delivery.

A glucose-responsive insulin delivery system that sustains blood glucose equilibrium for an extended duration can address the low therapeutic window of insulin in diabetes treatment. Herein, insulin is loaded in a water-in-oil-in-water (W1/O/W2) gelled multiple emulsion using poly (4-vinylphenylboronic acid) (PVPBA) homopolymer as an effective emulsifier. The gelled multiple emulsion exhibits a high encapsulation efficiency (99%), enhanced stability and remarkable shear-thinning behavior, making it easy to inject. Under hyperglycemic conditions, the gelled emulsion system instantly binds to glucose molecules and reduces the hydrogen bonds of the PVPBA homopolymer, resulting in insulin release. In a streptozotocin-induced type 1 diabetic mouse model, a single subcutaneous injection of the gelled emulsion rapidly responds to high blood glucose concentration (BGC)and release insulin in a glucose dependent manner, thus prolonging the antihyperglycemic effect compared with free insulin.

High free sugars, insulin resistance, and low socioeconomic indicators: the hubs in the complex network of non-communicable diseases in adolescents

BackgroundNoncommunicable diseases (NCDs) predominantly affect adults, but pathophysiological changes begin decades earlier, as a continuum, with initial events apparent in adolescence. Hence, early identification and intervention are crucial for the prevention and management of NCDs. We investigated the complex network of socioeconomic, behavioral, and metabolic factors associated with the presence of NCD in Brazilian adolescents.MethodsWe conducted a cross-sectional study nested within the São Luís segment of the Ribeirão Preto, Pelotas, and São Luís (RPS) cohort’s consortium, focusing on 18–19-year-olds (n = 2515). Data were collected prospectively, from which we constructed a complex network with NCD-related factors/indicators as nodes and their co-occurrences as edges. General and sex-based models analyzed: socioeconomic status, behavioral (smoking, alcohol, and other drugs use, unhealthy diet, poor sleep, physical inactivity), and metabolic factors (overweight/obesity, elevated blood pressure, poor lipid profile). We also looked for NCDs in adolescence like asthma, abnormal spirometry, depression, suicide risk, and poor oral health. The network was characterized by degree, betweenness, eigenvector, local transitivity, Shannon entropy, and cluster coefficient.ResultsThe adolescents had an average age of 18.3 years, 52.3% were female and 47.7% male. 99.8% of them have a diet rich in free sugars, 15% are overweight/obese and 72.3% had an elevated TyG index. High free sugar emerged as the central hub, followed by high TyG index (an early marker of insulin resistance) and low socioeconomic class. In males, low fiber intake and a high triglycerides/HDL ratio highlighted cardiometabolic concerns; in females, sedentary behavior and poor sleep marked metabolic and psychological challenges, along with caries in both sexes.ConclusionsOur findings provide insights into central health challenges during adolescence, such as high free sugars, insulin resistance, and low socioeconomic indicators, suggesting that interventions targeted at these central hubs could have a significant impact on their NCD network.

Fasting triglyceride concentrations are associated with markers of lipid metabolism and glucose homeostasis in healthy, non-obese dogs in lean and overweight condition.

Serum triglyceride concentrations increase in dogs with obesity, which is typically assessed by body condition score (BCS), however little is known about changes that take place in non-obese dogs in overweight condition. Further, the associations of triglyceride levels with other markers of energy homeostasis are poorly characterised in healthy animals. The present study aimed to evaluate associations between both BCS and triglyceride concentrations with other markers of lipid and glucose metabolism in healthy, non-obese dogs, as well as to assess whether these markers change significantly in non-obese dogs with overweight as compared to their lean counterparts. Serum concentrations of cholesterol, free fatty acids, triglycerides, insulin, glucose and fructosamine were measured in 532 healthy, client-owned dogs, assigned either to 'lean' (BCS: 3-5) or 'overweight' (BCS: 6-7) categories. Generalised linear mixed models were used to assess associations between BCS categories, triglyceride concentrations and other variables, correcting for the effect of breed. Compared with lean dogs, overweight dogs had a greater serum cholesterol concentration (95% CI, 5.3-6.2 mmol/L or 205-237 mg/dL versus 5.1-5.4 mmol/L or 198-210 mg/dL, p = 0.0032), insulin concentration (95% CI, 17.5-22.1 μU/ml versus 16.7-18.0 μU/ml, p = 0.0374) and were older (95% CI, 4.0-5.3 versus 3.4-3.7 years, p = 0.0005). Triglyceride concentrations were positively associated with fructosamine (r 2 = 0.31, p = 0.0012), cholesterol (r 2 = 0.25, p < 0.0001), insulin (r 2 = 0.14, p = 0.0030) and glucose (r 2 = 0.10, p = 0.0014) concentrations, and negatively associated with free fatty acid concentrations (r 2 = 0.11, p < 0.0001). However, there was no association between triglyceride concentrations and age. In conclusion, both BCS and triglyceride concentrations were associated with other markers of glucose and lipid metabolism in non-obese healthy dogs, amongst which those with overweight showed metabolic changes as compared to their lean counterparts. Triglyceride concentrations were associated with an increase in insulin and fructosamine concentrations that might reflect an early-phase impairment in glucose tolerance which, surprisingly, was concurrent with lower basal free fatty acid concentrations.

The Association between Vitamin D Status and the Impact of Metformin on Hypothalamic-Pituitary-Thyroid Axis Activity in Women with Subclinical Hypothyroidism.

Metformin inhibits enhanced secretion of anterior pituitary hormones. Its impact on prolactin and gonadotropin concentrations is absent in individuals with hypovitaminosis D. The aim of this prospective cohort study was to investigate whether vitamin D status determines the effect of metformin on hypothalamic-pituitary-thyroid axis activity in levothyroxine-naïve women. The study included three groups of women of reproductive age with subclinical non-autoimmune hypothyroidism, which were matched for age, thyroid-stimulating hormone (TSH) concentration, and insulin sensitivity: untreated women with vitamin D deficiency/insufficiency (group A), women effectively supplemented with exogenous calciferol (group B), and untreated women with normal 25-hydroxyvitamin D concentrations (25OHD) (group C). Owing to concomitant type 2 diabetes or prediabetes, all subjects were treated with metformin. Concentrations of 25OHD, TSH, total and free thyroid hormones, glucose, insulin, glycated hemoglobin (HbA1c), prolactin, and peripheral markers of thyroid hormone action were assayed before metformin treatment and six months later. Based on hormone concentration, structure parameters of thyroid homeostasis were calculated. Except for 25OHD concentrations, there were no between-group differences in baseline values of the measured variables. Metformin reduced glucose, the homeostatic model assessment 1 of insulin resistance ratio (HOMA1-IR), and HbA1c in all study group, but these effects were less pronounced in group A than in the remaining groups. The reduction in TSH and Jostel's index was observed only in groups B and C, and its degree correlated with baseline TSH concentrations, baseline 25OHD concentrations, and the degree of improvement in HOMA1-IR. The drug did not affect circulating levels of 25OHD, free and total thyroid hormones, prolactin, other structure parameters of thyroid homeostasis, and markers of thyroid hormone action. The obtained results allow us to conclude that low vitamin D status in young women mitigates the impact of metformin on thyrotroph secretory function.

Therapeutic effect of oral insulin-chitosan nanobeads pectin-dextrin shell on streptozotocin-diabetic male albino rats

The current study inspects the therapeutic effects of orally ingested insulin-loaded chitosan nanobeads (INS-CsNBs) with a pectin-dextrin (PD) coating on streptozotocin (STZ)-induced diabetes in Wistar rats. The study also assessed antioxidant effects in pancreatic tissue homogenate, insulin, C-peptide, and inflammatory markers interleukin-1 beta and interleukin-6 (IL-1β and IL-6) in serum. Additionally, histopathological and immunohistochemical examination of insulin granules, oxidative stress, nuclear factor kappa B (NF-κB P65), and sirtuin-1 (SIRT-1) protein detection, as well as gene expression of nuclear factor erythroid 2–related factor 2 (Nrf2), heme oxygenase-1 (HO-1), B-cell lymphoma 2 (Bcl2), and Bcl-2-associated X protein (Bax) in pancreatic tissue were investigated. After induction of diabetes with STZ, rats were allocated into 6 groups: the normal control (C), the diabetic control (D), and the diabetic groups treated with INS-CsNBs coated with PD shell (50 IU/kg) (NF), free oral insulin (10 IU/kg) (FO), CsNBs-PD shell (50 IU/kg) (NB), and subcutaneous insulin (10 IU/kg) (Sc). The rats were treated daily for four weeks. Treatment of diabetic rats with INS-CsNBs coated with PD shell resulted in a significant improvement in blood glucose levels, elevated antioxidant activities, decreased NF-κB P65, IL-1β, and IL-6 levels, upregulated Nrf-2 and HO-1, in addition to a marked improvement in the histological architecture and integrity compared to the diabetic group. The effects of oral INS-CsNBs administration were comparable to those of subcutaneous insulin. In conclusion, oral administration of INS-loaded Cs-NBs with a pectin-dextrin shell demonstrated an ameliorative effect on STZ-induced diabetes, avoiding the drawbacks of subcutaneous insulin.

Exploring the Association of Biochemical Characterization and Genetic Determinants of TNF-α, CXCR2, and CCR5 Delta 32 Mutation with Predisposition to Polycystic Ovary Syndrome.

In this case control study, we used amplification-refractory mutation system (ARMS)-PCR to detect and determine the presence of the polymorphic variants TNF-α, CCR5-delta32, and CXCR2 in the study subjects. These gene polymorphs may serve as critical candidate gene variants in PCOS pathogenesis and therapeutics. The case-control study's findings revealed that the majority of the biochemical and endocrine serum biomarkers examined in the investigation-including lipids (LDL, HDL, and cholesterol), T2DM markers (fasting glucose, free insulin, and HOMA-IR), and hormones (FSH, LH, testosterone, and progesterone)-exhibited statistically significant changes in PCOS patients. The distributions of TNF-α (rs1800629), CCR5-delta32, and CXCR2 (rs2230054) genotypes analyzed within PCOS patients and healthy controls in the considered population were significant (p < 0.05). The heterozygosity of CXCR2-CA, TNF-α GA, and CCR5(WT+Δ32*) genotypes was significantly associated with PCOS susceptibility, with high OR and p < 0.05 in the codominant model. Similarly, the A allele of the TNF-α and CXCR2 genes, along with the CCR5Δ32*(mutant) allele, was significantly associated with PCOS susceptibility, with high OR and p < 0.05. Likewise, the CXCR2 (CA+AA) vs CC genotype was associated with increased susceptibility to PCOS, with OR 2.25, p < 0.032. Our study concludes that TNF-α rs1800629G>A, CXCR2-rs2230054C>T, and CCR5-Delta32 rs333 are potential loci for developing PCOS in the Tabuk population. These findings might eventually be useful in identifying and classifying those who are at risk for PCOS. To validate these results, it is advised that further longitudinal studies be conducted in diverse ethnic populations and with larger sample sizes.

Effect of physical activity on free fatty acids, insulin resistance, and blood pressure in obese older women.

Obesity is characterized by a progressive increase in body fat accompanied by insulin resistance (IR) and elevated blood pressure (BP), and presents significant health risks, particularly in aged individuals. This study aimed to evaluate the effects of physical activity (PA) on free fatty acid (FFA) levels, IR, and BP in obese older women. Twenty-three participants were randomly assigned to either the control group (CON, n = 11) or the physical activity group (PA, n = 12). The PA group was provided with a target of achieving &gt;7,000 steps/day for 5 days each week. Body composition, FFA levels, IR, and BP were measured at pre- and post- of the 12-week intervention. The analysis revealed a statistically significant interaction between FFA (p &lt; 0.01), IR (p &lt; 0.01), and SBP (p &lt; 0.001). FFA (p &lt; 0.5), IR (p &lt; 0.5), and systolic blood pressure (SBP) (p &lt; 0.01) were significantly decreased in the PA group compared to those in the CON group, which showed no significant changes in FFA, IR, and SBP. PA significantly decreased FFA, IR, and SBP in older women with obesity. Therefore, PA is an effective intervention for the prevention and management of obesity and cardiovascular diseases in obese older women.

Intermittent hypoxia increases lipid insulin resistance in healthy humans: A randomized crossover trial.

Sympathetic overactivity caused by chronic intermittent hypoxia is a hallmark of obstructive sleep apnea. A high sympathetic tone elicits increases in plasma free fatty acid and insulin. Our objective was to assess the impact of 14 nights of chronic intermittent hypoxia exposure on sympathetic activity, glucose control, lipid profile and subcutaneous fat tissue remodelling in non-obese healthy humans. In this prospective, double-blinded crossover study, 12 healthy subjects were randomized, among them only nine underwent the two phases of exposures of 14 nights chronic intermittent hypoxia versus air. Sympathetic activity was measured by peroneal microneurography (muscle sympathetic nerve activity) before and after each exposure. Fasting glucose, insulin, C-peptide and free fatty acid were assessed at rest and during a multisampling oral glucose tolerance test. We assessed histological remodelling, adrenergic receptors, lipolysis and lipogenesis genes expression and functional changes of the adipose tissue. Two weeks of exposure of chronic intermittent hypoxia versus ambient air significantly increased sympathetic activity (p = 0.04). Muscle sympathetic nerve activity increased from 24.5 [18.9; 26.8] before to 21.7 [13.8; 25.7] after ambient air exposure, and from 20.6 [17.4; 23.9] before to 28.0 [24.4; 31.5] bursts per min after exposure to chronic intermittent hypoxia. After chronic intermittent hypoxia, post-oral glucose tolerance test circulating free fatty acid area under the curve increased (p = 0.05) and free fatty acid sensitivity to insulin decreased (p = 0.028). In adipocyte tissue, intermittent hypoxia increased expression of lipolysis genes (adipocyte triglyceride lipase and hormone-sensitive lipase) and lipogenesis genes (fatty acid synthase; p < 0.05). In this unique experimental setting in healthy humans, chronic intermittent hypoxia induced high sympathetic tone, lipolysis and decreased free fatty acid sensitivity to insulin. This might participate in the trajectory to systemic insulin resistance and diabetes for patients with obstructive sleep apnea.

Protein Ingredient Quality within Infant Formulas Impacts Plasma Amino Acid Concentrations in Neonatal Minipiglets

BackgroundInfant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps that may impact protein digestion and subsequent amino acid (AA) absorption. ObjectivesThe objective was to understand the impact of the protein ingredient quality within IFs on postprandial plasma AA profiles. MethodsFour isonitrogenous and isocaloric IFs were produced at a semi-industrial scale using whey proteins from different origins (cheese compared with ideal whey) and denaturation levels (IF-A, -B, -C), and caseins with different supramolecular organizations (IF-C, -D). Ten Yucatan minipiglets (12- to 27-d-old) were used as a human infant model and received each IF for 3 d according to a Williams Latin square followed by a 2-d wash-out period. Jugular plasma was regularly sampled from 10 min preprandial to 4 h postprandial on the third day to measure free AAs, urea, insulin, and glucose concentrations. Data were statistically analyzed using a mixed linear model with diet (IFs), time, and sex as fixed factors and piglet as random factor. ResultsIFs made with cheese whey (IF-A and -B) elicited significantly higher plasma total and essential AA concentrations than IFs made with ideal whey (IF-C and -D), regardless of the pre- and postprandial times. Most of the differences observed postprandially were explained by AA homeostasis modifications. IFs based on cheese whey induced an increased plasma concentration of Thr due to both a higher Thr content in these IFs and a Thr-limiting degrading capability in piglets. The use of a nonmicellar casein ingredient led to reduced plasma content of AA catabolism markers (IF-D compared with IF-C). ConclusionsOverall, our results highlight the importance of the protein ingredient quality (composition and structure) within IFs on neonatal plasma AA profiles, which may further impact infant protein metabolism.

Prepubertal children with obesity have high free IGF-1 levels and accelerated growth despite reduced pappalysin levels.

Prepubertal children with obesity frequently have enhanced growth, accelerated skeletal maturation and changes in the GH-IGF axis. However, the involvement of pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC1, STC2) as regulators of IGF bioavailability has not been studied in obesity. We aimed to determine the effects of childhood obesity and weight reduction on serum levels of PAPP-A, PAPP-A2, STC1 and STC2 and their relationship with IGF bioavailability, growth, and other components of the GH-IGF system. Prepubertal children with severe obesity (150, 50% males/females, age: 7.72 ± 2.05 years, BMI z-score: 4.95 ± 1.70, height z-score: 1.28 ± 1.04) were studied at diagnosis and after a minimum of 0.5 BMI z-score reduction. Two hundred and six healthy age- and sex-matched children were used as controls. Children with obesity had decreased serum concentrations of PAPP-A, PAPP-A2 and STC2, but increased total and free IGF-I (fIGF-I), intact IGFBP-3, ALS, IGF-II and insulin levels, with no difference in the free/total IGF-I ratio. Neither the standardized BMI nor height correlated with any biochemical parameter analyzed. A decrease in IGF-II, insulin, and ALS with an increase in IGFBP-2 and -5, STC2 and PAPP-A were observed after weight loss. Increased circulating total and free IGF-I, insulin and IGF-II may all contribute to the increased rate of prepubertal growth and bone maturation observed in children with obesity, with STC2 possibly being involved.

Exploring the Pathophysiology of ATP-Dependent Potassium Channels in Insulin Resistance.

Ionic channels are present in eucaryotic plasma and intracellular membranes. They coordinate and control several functions. Potassium channels belong to the most diverse family of ionic channels that includes ATP-dependent potassium (KATP) channels in the potassium rectifier channel subfamily. These channels were initially described in heart muscle and then in other tissues such as pancreatic, skeletal muscle, brain, and vascular and non-vascular smooth muscle tissues. In pancreatic beta cells, KATP channels are primarily responsible for maintaining the membrane potential and for depolarization-mediated insulin release, and their decreased density and activity may be related to insulin resistance. KATP channels' relationship with insulin resistance is beginning to be explored in extra-pancreatic beta tissues like the skeletal muscle, where KATP channels are involved in insulin-dependent glucose recapture and their activation may lead to insulin resistance. In adipose tissues, KATP channels containing Kir6.2 protein subunits could be related to the increase in free fatty acids and insulin resistance; therefore, pathological processes that promote prolonged adipocyte KATP channel inhibition might lead to obesity due to insulin resistance. In the central nervous system, KATP channel activation can regulate peripheric glycemia and lead to brain insulin resistance, an early peripheral alteration that can lead to the development of pathologies such as obesity and Type 2 Diabetes Mellitus (T2DM). In this review, we aim to discuss the characteristics of KATP channels, their relationship with clinical disorders, and their mechanisms and potential associations with peripheral and central insulin resistance.

Metabolomics and gut metagenomics profile of the healthy adults on consumption of whey protein supplemented with enzymes-probiotics blend

In this randomized, crossover, pilot clinical study, we aimed to evaluate the effect of supplementation of enzymes-probiotics blend with whey protein on the amino acid absorption and gut microbiota. Healthy subjects were supplemented with the whey protein and test i.e. Pepzyme Pro (enzymes-probiotics blend) or placebo i.e. maltodextrin for 15 days with the washout period of 30 days. Blood samples were analyzed for plasma free amino acids, insulin, and CRP. Additionally, urine nitrogen, fecal nitrogen, and gut microbiota were evaluated. On day 15, the test arm showed upward trend in rate of amino acid absorption than placebo arm within 30 min of post ingestion of protein. Moreover, rate of absorption of few essential and branched chain amino acids were significantly higher (methionine (p = 0.049), leucine (p = 0.014), isoleucine (p = 0.053)) in the test arm on day 15. Total branched chain amino acids absorption were found to be significantly higher (p ≤ 0.05) in the test arm than the placebo arm within 30 min of post ingestion on day 15. Uptrend in total amino acid absorption and Cmax, and downtrend in Tmax was observed on day 15 in the test arm. The CRP, fecal nitrogen, and urine nitrogen remained unaltered after supplementation. Microbiota profiling showed significant change in abundance of species of genus Bacteroides and phylum Bacteroidetes. Overall, metagenomics and metabolomics based assessments demonstrated that the consumption of Pepzyme Pro with whey protein could potentially improve protein digestion, amino acid absorption, and modulate gut microbiota.Clinical trial registration The clinical trial registry of India CTRI/2021/09/036169 [Registered on: 02/09/2021]

Impact of bariatric surgery on ovarian reserve markers and its correlation with nutritional parameters and adipokines.

A reduction in anti-müllerian hormone (AMH) levels at short-term after bariatric surgery (BS) has been previously described. However, an assessment of ovarian reserve at longer-follow up, and a comprehensive evaluation of the potentially implicated factors has not been reported. Prospective cohort study. Twenty women aged 18-40 years with BMI 43.95 kg/m2 undergoing BS were studied at baseline (BS0), and at 1 month (BS1), 4 months (BS2), 12 months (BS3), and 24-36 months (BS4) after the surgery. Anthropometrics, reproductive hormones (AMH, FSH, LH, estradiol, testosterone, SHBG, androstenedione), metabolic parameters (adiponectin, leptin, ghrelin, insulin), and nutritional blood parameters (markers of nutritional status, vitamins, and minerals) were obtained at each study time point. Antral follicular count (AFC) was assessed by ultrasonography at BS0, BS3, and BS4. Mixed models were used for analysis of longitudinal data. The mean AMH level was 3.88 ng/mL at BS0, decreased at BS3 (mean= 2.59 ng/mL; p=0.009), and remained stable between BS3 and BS4 (mean= 2.96 ng/mL; p=0.409). We also observed a non-significant decrease in AFC at BS3 (mean=26.14 at BS0, mean 16.81 at BS3; p=0.088) that remained stable at BS4 (mean= 17.86; p=0.731). Mixed models analysis showed: (a) a decrease in 10kg of body weight was associated with an average decrease of 0.357 ng/mL in AMH (p=0.014); (b) a decrease in 1 BMI point was associated with an average decrease of 0.109 ng/mL in AMH (p=0.005); (c) an increase in 1 µg/mL of adiponectin was associated with an average decrease of 0.091 ng/ml in AMH (p=0.041) Significant positive correlations were found between the AMH levels after BS and plasma concentrations of testosterone, free androgen index, insulin and HOMA index. No significant correlations were detected between AMH levels and nutritional parameters. Our results were in line with previous observations, showing that AMH levels decreased significantly at 12 months after bariatric surgery, in parallel with a non-significant reduction in AFC. Both ovarian reserve markers showed a later stabilization up to the end of the study. Of note, postoperative AMH levels were positively correlated with key androgen and insulin resistance-related parameters.

Investigating and Optimizing Insulin Partitioning with Conjugated Au Nanoparticles in Aqueous Two-Phase Systems Using Response Surface Methodology.

This study investigated the impact of bioconjugation on the partitioning of insulin, a clinically valuable protein, in an aqueous two-phase system. Gold nanoparticles of different sizes were synthesized and conjugated with insulin. Analysis of the conjugated insulin showed that the insulin remains fully active. Conjugated gold nanoparticles (AuNPs/insulin) were used in polyethylene glycol (PEG)-dextran aqueous two-phase systems to investigate the effect of pH, PEG and dextran molecular weights, PEG and dextran concentrations, AuNPs/insulin dosage, and nanoparticle size on the partition coefficient. These systems were chosen for their biocompatibility and low toxicity. Response surface methodology with D-optimal design was used to model and optimize these systems and their affected parameters. At the optimum condition of a pH = 8 system containing 21% PEG 4000, 5% dextran 100,000, and 100 IU AuNPs/insulin, the partition coefficient of AuNPs/insulin was found to be 192.96, which is in agreement with the empirical partition coefficient of 189.2. This is significantly higher than the partition coefficient of free insulin in a similar system. This approach could be used to overcome limitations in the feasibility of aqueous two-phase systems for industrial-scale purification of biomolecules and biopharmaceuticals.

The Effects of Myo-Inositol and D-Chiro-Inositol in a Ratio 40:1 on Hormonal and Metabolic Profile in Women with Polycystic Ovary Syndrome Classified as Phenotype A by the Rotterdam Criteria and EMS-Type 1 by the EGOI Criteria

Setting: Insulin resistance (IR) and compensatory hyperinsulinemia are considered contributing factors toward polycystic ovary syndrome (PCOS). Objectives: This study evaluates the frequency of metabolic abnormalities in PCOS patients and the effects of myo-inositol (MI) and D-chiro-inositol (DCI), in a 40:1 ratio on hormonal and metabolic parameters. Participants: Thirty-four women with PCOS phenotype A (endocrine-metabolic syndrome [EMS-type 1]) between the ages of 20–40. Design: Open prospective study with phenotype A (EMS-type I, n = 34) supplemented with 2,255 mg/day of inositol (MI and DCI in a 40:1 ratio) for 3 months. Methods: The following were measured before and after treatment: serum levels of follicular stimulating hormone, luteinizing hormone (LH), estradiol, total and free testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), anti-Müllerian hormone, glucose, insulin, HOMA-IR, and body mass index (BMI). Results: 55.9% of the enrolled patients were overweight or obese, 50% affected by IR, 17.6% with a history of gestational diabetes mellitus, and 61.8% had familial diabetes mellitus. At the conclusion of the study, BMI (p = 0.0029), HOMA-IR (p < 0.001) significantly decreased, along with decreased numbers of patients with elevated insulin levels. The supplementation resulted in decreased total testosterone (p < 0.001), free testosterone (p < 0.001), FAI (p < 0.001), and LH (p < 0.001); increased SHBG (p < 0.001) and estradiol (p < 0.001). Limitations: The present analysis was limited to a 12-week follow-up, which precluded a long-term evaluation of the effects of MI and DCI combination. Also, this period was insufficient to achieve and analyze clinical changes such as restoration of the menstrual cycle, restoration of reproductive function, and clinical manifestations of hyperandrogenism. Conclusions: Supplementation improved metabolic and hormonal profile in PCOS phenotype A (EMS-type I) patients. This builds upon previous work that demonstrated that combined inositol treatment may be effective in PCOS. The study presented herein, used a reduced concentration than in prior literature; however, a significant change in hormonal and metabolic parameters was still observed.

Development of polysaccharide-coated layered double hydroxide nanocomposites for enhanced oral insulin delivery

Oral insulin (INS) is predicted to have the most therapeutic advantages in treating diabetes to repress hepatic glucose production through its potential to mimic the endogenous insulin pathway. Many oral insulin delivery systems have been investigated. Layered double hydroxide (LDH) as an inorganic material has been widely used in drug delivery thanks to its appealing features such as good biocompatibility, low toxicity, and excellent loading capability. However, when used in oral drug delivery, the effectiveness of LDH is limited due to the acidic degradation in the stomach. In this study, to overcome these challenges, chitosan (Chi) and alginate (Alg) dual-coated LDH nanocomposites with the loading of insulin (Alg-Chi-LDH@INS) were developed by the layered-by-layered method for oral insulin delivery with dynamic size of ~ 350.8 nm, negative charge of ~ − 13.0 mV, and dispersity index 0.228. The insulin release profile was evaluated by ultraviolet–visible spectroscopy. The drug release profiles evidenced that alginate and chitosan coating partially protect insulin release from a burst release in acidic conditions. The analysis using flow cytometry showed that chitosan coating significantly enhanced the uptake of LDH@INS by Caco-2 cells compared to unmodified LDH and free insulin. Further in the in vivo study in streptozocin-induced diabetic mice, a significant hypoglycemic effect was maintained following oral administration with great biocompatibility (~ 50% blood glucose level reduction at 4 h). This research has thus provided a potential nanocomposite system for oral delivery of insulin.Graphical

A review on oral novel delivery systems of insulin through the novel delivery system formulations: A review.

Parenteral administration of insulin remains the most common route of administration, causing local hypertrophy at the injection sites because of multiple daily injections. Because of this, there is an interest and effort in oral insulin administration that is convenient and mimics the physiology of endogenous insulin secreted in the liver. However, oral insulin encountered different challenges due to abundant enzyme degradation, the presence of a mucus layer, and the underlying intestinal epithelial membrane barrier in the gastrointestinal tract. This narrative review reviewed the literature dealing with novel oral insulin delivery approaches. Various pieces of literature were searched, filtered, and reviewed from different sources, and the information obtained was organized, formulated, and finalized. Oral insulin has been formulated and extensively studied in various novel delivery approaches, such as nanoparticles, microspheres, mucoadhesive patches, encapsulations, hydrogels, ionic liquids, liposomes, and complexation. The efficiency of these formulations demonstrated improved efficiency and potency compared to free oral insulin delivery, but none of them have greater or equivalent potency to subcutaneous insulin. Future studies regarding dose-dependent therapeutic efficacy and the development of new novel formulations to produce comparable oral insulin to subcutaneous insulin are warranted to further support the suitability of the current platform for oral insulin delivery.

A high-fat eucaloric diet induces reprometabolic syndrome of obesity in normal weight women.

We examined the effects of 1 month of a eucaloric, high-fat (48% of calories) diet (HFD) on gonadotropin secretion in normal-weight women to interrogate the role of free fatty acids and insulin in mediating the relative hypogonadotropic hypogonadism of obesity. Eighteen eumenorrheic women (body mass index [BMI] 18-25 kg/m2) were studied in the early follicular phase of the menstrual cycle before and after exposure to an HFD with frequent blood sampling for luteinizing hormone (LH) and follicle-stimulating hormone (FSH), followed by an assessment of pituitary sensitivity to gonadotropin-releasing hormone (GnRH). Mass spectrometry-based plasma metabolomic analysis was also performed. Paired testing and time-series analysis were performed as appropriate. Mean endogenous LH (unstimulated) was significantly decreased after the HFD (4.3 ± 1.0 vs. 3.8 ± 1.0, P < 0.01); mean unstimulated FSH was not changed. Both LH (10.1 ± 1.0 vs. 7.2 ± 1.0, P < 0.01) and FSH (9.5 ± 1.0 vs. 8.8 ± 1.0, P < 0.01) responses to 75 ng/kg of GnRH were reduced after the HFD. Mean LH pulse amplitude and LH interpulse interval were unaffected by the dietary exposure. Eucaloric HFD exposure did not cause weight change. Plasma metabolomics confirmed adherence with elevation of fasting free fatty acids (especially long-chain mono-, poly-, and highly unsaturated fatty acids) by the last day of the HFD. One-month exposure to an HFD successfully induced key reproductive and metabolic features of reprometabolic syndrome in normal-weight women. These data suggest that dietary factors may underlie the gonadotrope compromise seen in obesity-related subfertility and therapeutic dietary interventions, independent of weight loss, may be possible.

Reduction in Pappalysin-2 Levels and Lower IGF-I Bioavailability in Female Adolescents With Anorexia Nervosa.

Anorexia nervosa (AN) can cause severe undernutrition associated with alterations in the IGF axis. Pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC-1, STC-2) modulate IGF binding-protein (IGFBP) cleavage and IGF bioavailability, but their implications in AN are unknown. We determined serum levels of PAPP-As and STCs in relationship with classical IGF axis parameters in female adolescents with AN and their association with nutritional status and secondary amenorrhea. Parameters of the IGF axis were determined in fasting serum samples of 68 female adolescents with AN at diagnosis and 62 sex- and age-matched controls. Standardized body mass index (BMI) and bone mineral density (BMD) were calculated. Patients with AN had lower concentrations of total and free IGF-I, total IGFBP-3, acid-labile subunit (ALS), insulin, PAPP-A2, STC-1, and STC-2 and higher levels of IGF-II and IGFBP-2. Their free/total IGF-I ratio was decreased and the intact/total IGFBP-3 and -4 ratios increased. BMI was directly related to total IGF-I and intact IGFBP-3 and inversely with IGFBP-2 and intact IGFBP-4. Weight loss was directly correlated with intact IGFBP-4 and negatively with intact IGFBP-3, ALS, STC-2, and PAPP-A2 concentrations. BMD was directly related to intact IGFBP-3 and inversely with intact IGFBP-4 and PAPP-A2 levels. Patients with amenorrhea had lower levels of total IGF-I and IGFBP-3 than those with menses. The reduction of PAPP-A2 in patients with AN may be involved in a decline in IGFBP cleavage, which could underlie the decrease in IGF-I bioavailability that is influenced by nutritional status and amenorrhea.