L-Arginine supplementation improves insulin sensitivity and beta cell function in the offspring of diabetic rats through AKT and PDX-1 activation

Improved insulin sensitivity and reproductive profile in overweight/obese PCOS patients undergoing integrative treatment with carnitines, L-arginine, L-cysteine and myo-inositol

OBJECTIVE

To evaluate the effects of a combination of carnitines, L-arginine, L-cysteine and myo-inositol on metabolic and reproductive parameters in PCOS overweight/obese patients.

METHODS

This was a retrospective study analyzing information of a group of PCOS (n = 25) overweight/obesity patients, not requiring hormonal treatment, selected from the database of the ambulatory clinic of the Gynecological Endocrinology Center at the University of Modena and Reggio Emilia, Modena, Italy. The hormonal profile, routine exams and insulin and C-peptide response to oral glucose tolerance test (OGTT) were evaluated before and after 12 weeks of a daily oral complementary treatment with L-carnitine (500 mg), acetyl-L-carnitine (250 mg), L-arginine (500 mg), L-cysteine (100 mg) and myo-inositol (1 gr). The hepatic insulin extraction index was also calculated.

RESULTS

The mix of complementary substances significantly improved metabolic parameters, homeostatic model assessment for insulin resistance index values and gonadotropin plasma levels. Glucose, C-peptide and insulin response to OGTT was significantly reduced as well as the hepatic insulin extraction index.

CONCLUSION

The administration of a combination of carnitines, L-arginine, L-cysteine and myoinositol improved gonadotropin plasma levels and insulin sensitivity in overweight/obese PCOS patients and restored hepatic clearance of insulin as demonstrated by the decreased hepatic insulin extraction index.

Fenugreek seeds as a natural source of L-arginine-encapsulated lipid nanoparticles against diabetes

Diabetes, affecting over 10.5% of the global population, leads to severe health complications and economic burdens, highlighting the urgent need for effective therapeutic approaches. Current treatments are often insufficient, prompting the exploration of novel therapeutic agents and delivery mechanisms. This study addresses this gap by investigating the roles of L-arginine (identified as a target drug candidate through network pharmacology) in diabetes management, while also evaluating lipid nanocarriers synthesized from fenugreek seed oil for improved drug delivery. Our docking analyses revealed L-arginine's strong interactions with diabetes-target genes (CYP1A2, CYP2C19, and NFKB), with multiple hydrogen bonds and binding energies ranging from - 7.2 to - 8.9 kcal/mol. Encapsulated L-arginine lipid nanoparticles were characterized using UV-Visible spectroscopy, showing absorbance peaks at 415 nm for simple nanoparticles and 521 nm for L-arginine-loaded nanoparticles. Scanning electron microscopy confirmed an average nanoparticle size of 100.2 nm, and zeta potential analysis indicated a neutral surface charge (- 9.37 mV). Antioxidative activity showed 84.44% inhibition with an IC50 value of 40.5 µg/mL The nanoparticles inhibited albumin denaturation by 81.10% and alpha-amylase by 89.30%, surpassing metformin (78.43% at 1000 µg/mL). Hemolysis percentage was minimal at 10.54%. These findings demonstrate the potential of L-arginine as an anti-diabetic agent and highlight the efficacy of lipid nanocarriers as innovative drug delivery systems, providing a foundation for advancing therapeutic interventions against diabetes.

Maternal Dietary Strategies for Improving Offspring Cardiovascular-Kidney-Metabolic Health: A Scoping Review

Dietary regulation has been recognized for its profound impact on human health. The convergence of cardiovascular, kidney, and metabolic disorders at the pathophysiological level has given rise to cardiovascular-kidney-metabolic (CKM) syndrome, which constitutes a significant global health burden. Maternal dietary nutrients play a crucial role in fetal development, influencing various programmed processes. This review emphasizes the effects of different types of dietary interventions on each component of CKM syndrome in both preclinical and clinical settings. We also provide an overview of potential maternal dietary strategies, including amino acid supplementation, lipid-associated diets, micronutrients, gut microbiota-targeted diets, and plant polyphenols, aimed at preventing CKM syndrome in offspring. Additionally, we discuss the mechanisms mediated by nutrient-sensing signals that contribute to CKM programming. Altogether, we underscore the interaction between maternal dietary interventions and the risk of CKM syndrome in offspring, emphasizing the need for continued research to facilitate their clinical translation.

Amino Acids during Pregnancy and Offspring Cardiovascular-Kidney-Metabolic Health

Amino acids are essential for normal pregnancy and fetal development. Disruptions in maternal amino acid metabolism have been associated with various adult diseases later in life, a phenomenon referred to as the developmental origins of health and disease (DOHaD). In this review, we examine the recent evidence highlighting the significant impact of amino acids on fetal programming, their influence on the modulation of gut microbiota, and their repercussions on offspring outcomes, particularly in the context of cardiovascular-kidney-metabolic (CKM) syndrome. Furthermore, we delve into experimental studies that have unveiled the protective effects of therapies targeting amino acids. These interventions have demonstrated the potential to reprogram traits associated with CKM in offspring. The discussion encompasses the challenges of translating the findings from animal studies to clinical applications, emphasizing the complexity of this process. Additionally, we propose potential solutions to overcome these challenges. Ultimately, as we move forward, future research endeavors should aim to pinpoint the most effective amino-acid-targeted therapies, determining the optimal dosage and mode of administration. This exploration is essential for maximizing the reprogramming effects, ultimately contributing to the enhancement of cardiovascular-kidney-metabolic health in offspring.

Applications of L-Arginine in Pregnancy and Beyond: An Emerging Pharmacogenomic Approach

L-arginine is a semi-essential amino acid that plays a critical role in various physiological processes, such as protein synthesis, wound healing, immune function, and cardiovascular regulation. The use of L-arginine in pregnancy has been an emerging topic in the field of pharmacogenomics. L-arginine, an amino acid, plays a crucial role in the production of nitric oxide, which is necessary for proper placental development and fetal growth. Studies have shown that L-arginine supplementation during pregnancy can have positive effects on fetal growth, maternal blood pressure, and the prevention of preeclampsia. This emerging pharmacogenomic approach involves using genetic information to personalize L-arginine dosages for pregnant women based on their specific genetic makeup. By doing so, it may be possible to optimize the benefits of L-arginine supplementation during pregnancy and improve pregnancy outcomes. This paper emphasizes the potential applications of L-arginine in pregnancy and the use of pharmacogenomic approaches to enhance its effectiveness. Nonetheless, the emerging pharmacogenomic approach to the application of L-arginine offers exciting prospects for the development of novel therapies for a wide range of diseases.

Disruption of O-Linked N-Acetylglucosamine Signaling in Placenta Induces Insulin Sensitivity in Female Offspring

Placental dysfunction can lead to fetal growth restriction which is associated with perinatal morbidity and mortality. Fetal growth restriction increases the risk of obesity and diabetes later in life. Placental O-GlcNAc transferase (OGT) has been identified as a marker and a mediator of placental insufficiency in the setting of prenatal stress, however, its role in the fetal programming of metabolism and glucose homeostasis remains unknown. We aim to determine the long-term metabolic outcomes of offspring with a reduction in placental OGT. Mice with a partial reduction and a full knockout of placenta-specific OGT were generated utilizing the Cre-Lox system. Glucose homeostasis and metabolic parameters were assessed on a normal chow and a high-fat diet in both male and female adult offspring. A reduction in placental OGT did not demonstrate differences in the metabolic parameters or glucose homeostasis compared to the controls on a standard chow. The high-fat diet provided a metabolic challenge that revealed a decrease in body weight gain (p = 0.02) and an improved insulin tolerance (p = 0.03) for offspring with a partially reduced placental OGT but not when OGT was fully knocked out. Changes in body weight were not associated with changes in energy homeostasis. Offspring with a partial reduction in placental OGT demonstrated increased hepatic Akt phosphorylation in response to insulin treatment (p = 0.02). A partial reduction in placental OGT was protective from weight gain and insulin intolerance when faced with the metabolic challenge of a high-fat diet. This appears to be, in part, due to increased hepatic insulin signaling. The findings of this study contribute to the greater understanding of fetal metabolic programming and the effect of placental OGT on peripheral insulin sensitivity and provides a target for future investigation and clinical applications.

Physiological effects of nutrients on insulin release by pancreatic beta cells

Obesity and type 2 diabetes (T2D) are growing health problems associated with a loss of insulin sensitivity. Both conditions arise from a long-term energy imbalance, and frequently, lifestyle measures can be useful in its prevention, including physical activity and a healthy diet. Pancreatic β-cells are determinant nutrient sensors that participate in energetic homeostasis needs. However, when pancreatic β-cells are incapable of secreting enough insulin to counteract the reduced sensitivity, the pathology evolves to an insulin resistance condition. The primary nutrient that stimulates insulin secretion is glucose, but also, there are multiple dietary and hormonal factors influencing that response. Many studies of the physiology of β-cells have highlighted the importance of glucose, fructose, amino acids, and free fatty acids on insulin secretion. The present review summarizes recent research on how β-cells respond to the most abundant nutrients that influence insulin secretion. Taken together, understand the subjacent mechanisms of each nutrient on β-cells can help to unravel the effects of mixed variables and complexity in the context of β-cell pathology.

Amino Acids and Developmental Origins of Hypertension

During pregnancy, amino acids are important biomolecules that play essential roles in fetal growth and development. Imbalanced amino acid intake during gestation may produce long-term morphological or functional changes in offspring, for example, developmental programming that increases the risk of developing hypertension in later life. Conversely, supplementation with specific amino acids could reverse the programming processes in early life, which may counteract the rising epidemic of hypertension. This review provides an overview of the evidence supporting the importance of amino acids during pregnancy and fetal development, the impact of amino acids on blood pressure regulation, insight from animal models in which amino acids were used to prevent hypertension of developmental origin, and interactions between amino acids and the common mechanisms underlying development programming of hypertension. A better understanding of the pathophysiological roles of specific amino acids and their interactions in developmental programming of hypertension is essential so that pregnant mothers are able to benefit from accurate amino acid supplementation during pregnancy in order to prevent hypertension development in their children.

Impact of Arginine Nutrition and Metabolism during Pregnancy on Offspring Outcomes

By serving as a precursor for the synthesis of nitric oxide, polyamines, and other molecules with biological importance, arginine plays a key role in pregnancy and fetal development. Arginine supplementation is a potential therapy for treating many human diseases. An impaired arginine metabolic pathway during gestation might produce long-term morphological or functional changes in the offspring, namely, developmental programming to increase vulnerability to developing a variety of non-communicable diseases (NCDs) in later life. In contrast, reprogramming is a strategy that shifts therapeutic interventions from adulthood to early-life, in order to reverse the programming processes, which might counterbalance the rising epidemic of NCDs. This review presented the role of arginine synthesis and metabolism in pregnancy. We also provided evidence for the links between an impaired arginine metabolic pathway and the pathogenesis of compromised pregnancy and fetal programming. This was followed by reprogramming strategies targeting the arginine metabolic pathway, to prevent the developmental programming of NCDs. Despite emerging evidence from experimental studies showing that targeting the arginine metabolic pathway has promise as a reprogramming strategy in pregnancy to prevent NCDs in the offspring, these results need further clinical application.

The Good, the Bad, and the Ugly of Pregnancy Nutrients and Developmental Programming of Adult Disease

Maternal nutrition plays a decisive role in developmental programming of many non-communicable diseases (NCDs). A variety of nutritional insults during gestation can cause programming and contribute to the development of adult-onset diseases. Nutritional interventions during pregnancy may serve as reprogramming strategies to reverse programming processes and prevent NCDs. In this review, firstly we summarize epidemiological evidence for nutritional programming of human disease. It will also discuss evidence from animal models, for the common mechanisms underlying nutritional programming, and potential nutritional interventions used as reprogramming strategies.

Microbiome Alteration in Type 2 Diabetes Mellitus Model of Zebrafish

Understanding the gut microbiota in metabolic disorders, including type 2 diabetes mellitus (T2DM), is now gaining importance due to its potential role in disease risk and progression. We previously established a zebrafish model of T2DM, which shows glucose intolerance with insulin resistance and responds to anti-diabetic drugs. In this study, we analysed the gut microbiota of T2DM zebrafish by deep sequencing the 16S rRNA V3-V4 hypervariable regions, and imputed a functional profile using predictive metagenomic tools. While control and T2DM zebrafish were fed with the same kind of feed, the gut microbiota in T2DM group was less diverse than that of the control. Predictive metagenomics profiling using PICRUSt revealed functional alternation of the KEGG pathways in T2DM zebrafish. Several amino acid metabolism pathways (arginine, proline, and phenylalanine) were downregulated in the T2DM group, similar to what has been previously reported in humans. In summary, we profiled the gut microbiome in T2DM zebrafish, which revealed functional similarities in gut bacterial environments between these zebrafish and T2DM affected humans. T2DM zebrafish can become an alternative model organism to study host-bacterial interactions in human obesity and related diseases.

Protective effects of either C-peptide or l-arginine on pancreatic β-cell function, proliferation, and oxidative stress in streptozotocin-induced diabetic rats

Diabetes and cardiometabolic risk factors including hypertension and dyslipidemia are the major threats to human health in the 21st century. Apoptosis in pancreatic tissue is one of the major causes of diabetes type 1 progression. The aim of this study was to investigate the effects of C-peptide or l-arginine on some cardiometabolic risk factors, pancreatic morphology, function and apoptosis, and the mechanisms of their actions. Forty adult male albino rats were divided into four equal groups: 1-control nondiabetic, 2-diabetic (no treatment), 3-diabetic + C-peptide, and 4-diabetic +  l-arginine. Diabetes was induced by a single intraperitoneal injection of high dose streptozotocin. At the end of the experiment, sera glucose, insulin levels, total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), and pancreatic MDA, TAC, and B-cell lymphoma 2 were measured. The morphology and proliferating activity of the pancreas were examined by hematoxylin and eosin histological stain, proliferative cell nuclear antigen (PCNA), and insulin antibodies. Our results showed that induction of diabetes caused hyperglycemia, dyslipidemia, and oxidative stress. However, administration of C-peptide or l-arginine significantly improved the pancreatic histopathology with a significant increase in the area % of insulin immunoreactivity, the number of PCNA immunopositive cells, the number of islets, and the diameter of islets compared with the diabetic group. C-peptide treatment of the diabetic rats completely corrected these errors, while l-arginine partially antagonized the above diabetic complications. So the administration of C-peptide as an adjuvant therapy in type 1 diabetes can significantly decrease apoptosis of pancreas and subsequent progression of diabetes complication.

COX2 and NOS3 gene polymorphisms in women with gestational diabetes

BACKGROUND

Gestational diabetes (GDM) is carbohydrate intolerance occurring in pregnancy. Low-grade inflammation plays an important role in the pathogenesis of this disorder. The present study aimed to examine the association between COX2 (rs6681231) and NOS3 (rs1799983 and rs2070744) gene polymorphisms and GDM.

METHODS

The study included 204 pregnant women with GDM and 207 pregnant women with normal glucose tolerance. The diagnosis of GDM was based on a 75-g oral glucose tolerance test at 24-28 weeks of gestation.

RESULTS

We observed an increased frequency of COX2 rs6681231 CC and GC genotype carriers among women with GDM (CC + GC versus GG, odds ratio = 1.55, 95% confidence interval = 1.01-2.36, p = 0.043; C versus G, odds ratio = 1.59, 95% confidence interval = 1.10-2.30, p = 0.013). There were no statistically significant differences in the distribution of NOS3 rs1799983 and rs2070744 between GDM and healthy women. Moreover, among women treated with insulin, we observed an increased frequency of COX2 rs6681231 CC and NOS3 rs1799983 TT genotype carriers.

CONCLUSIONS

The results of the present study suggest that the CC genotype of the COX2 rs6681231 polymorphism is associated with an increased risk of GDM and the need for insulin therapy, whereas the TT genotype of the NOS3 rs1799983 polymorphism may be associated with the need for insulin therapy in women with GDM.

The arginine metabolome in acute lymphoblastic leukemia can be targeted by the pegylated-recombinant arginase I BCT-100

Arginine is a semi-essential amino acid that plays a key role in cell survival and proliferation in normal and malignant cells. BCT-100, a pegylated (PEG) recombinant human arginase, can deplete arginine and starve malignant cells of the amino acid. Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood, yet for patients with high risk or relapsed disease prognosis remains poor. We show that BCT-100 is cytotoxic to ALL blasts from patients in vitro by necrosis, and is synergistic in combination with dexamethasone. Against ALL xenografts, BCT-100 leads to a reduction in ALL engraftment and a prolongation of survival. ALL blasts express the arginine transporter CAT-1, yet the majority of blasts are arginine auxotrophic due to deficiency in either argininosuccinate synthase (ASS) or ornithine transcarbamylase (OTC). Although endogenous upregulation or retroviral transduced increases in ASS or OTC may promote ALL survival under moderately low arginine conditions, expression of these enzymes cannot prevent BCT-100 cytotoxicity at arginine depleting doses. RNA-sequencing of ALL blasts and supporting stromal cells treated with BCT-100 identifies a number of candidate pathways which are altered in the presence of arginine depletion. Therefore, BCT-100 provides a new clinically relevant therapeutic approach to target arginine metabolism in ALL.

Clinical application of a novel diagnostic scheme including pancreatic β‑cell dysfunction for traumatic multiple organ dysfunction syndrome

A novel diagnostic scheme that includes pancreatic β‑cell dysfunction analysis for the diagnosis of traumatic multiple organ dysfunction syndrome (MODS) was investigated to assist in the early diagnosis and detection of MODS. Early intervention and treatment of MODS has been associated with a reduced mortality rate. A total of 2,876 trauma patients (including patients post‑major surgery) were admitted to the intensive care unit of the authors' hospital between December 2010 and December 2015 and enrolled in the present study. There were 205 cases where the patient succumbed to their injuries. In addition to the conventional diagnostic scheme for traumatic MODS, indexes of pancreatic β‑cell dysfunction [fasting blood‑glucose (FBG), homeostatic model assessment‑β and (blood insulin concentration 30 min following glucose loading‑fasting insulin concentration)/(blood glucose concentration 30 min following glucose loading‑FBG concentration)] were included to establish an improved diagnostic scheme for traumatic MODS. The novel scheme was subsequently used in clinical practice alongside the conventional scheme and its effect was evaluated. The novel scheme had a significantly higher positive number of MODS diagnoses for all trauma patients compared with the conventional scheme (12.48 vs. 8.87%; P<0.01). No significant difference was identified in the final percentage of positive of MODS diagnoses for trauma‑associated mortality patients between the novel (88.30%) and the conventional scheme (86.34%). The novel scheme had a significantly higher positive number of MODS diagnoses for trauma‑associated mortality patients 3 days prior to patients succumbing to MODS compared with the conventional scheme (80.98 vs. 64.39%; P<0.01). The consensus of the MODS diagnosis of all trauma patients between the novel scheme and the conventional scheme was 100%; however, out of the patients diagnosed as positive by novel scheme 71.03% were positive by the conventional scheme. The consensus between the final MODS diagnosis and the MODS diagnosis 3 days prior to patients succumbing to their injuries between the novel scheme and the conventional scheme was 100%; however, out of the patients diagnosed as positive by novel scheme 97.79 were positive by the conventional scheme of the 205 patients who succumbed to MODS and out of the patients diagnosed as positive for MODS by novel scheme 3 days prior to succumbing, 79.52% were positive by the conventional scheme. The results of the present study demonstrated that the novel diagnostic scheme using the relevant indexes of pancreatic β‑cell dysfunction for diagnosis of traumatic MODS, was able to diagnose MODS early without excessively extending the diagnostic scope. Its clinical application should be promoted.

Arginine and aerobic training prevent endothelial and metabolic alterations in rats at high risk for the development of the metabolic syndrome

Endothelial function is a key mechanism in the development of CVD. Arginine and exercise are important non-pharmacological strategies for mitigating the impact of metabolic changes in the metabolic syndrome, but the effect of their combined administration is unknown. Thus, the aim of this study was to investigate the isolated and combined effects of aerobic training and arginine supplementation on metabolic variables and vascular reactivity in rats at high risk for developing the metabolic syndrome. Wistar rats were divided into two groups: control and fructose (F – water with 10 % fructose). After 2 weeks, the F group was divided into four groups: F, fructose+arginine (FA, 880 mg/kg per d of l-arginine), fructose+training (FT) and fructose+arginine+training (FTA); treatments lasted for 8 weeks, and no difference was observed in body mass gain. Arginine did not improve the body protein content, and both the FA and FT groups show a reversal of the increase in adipose tissue. Insulin increase was prevented by training and arginine, without additive effect, and the increase in serum TAG was prevented only by training. The F group showed impaired endothelium-dependent vasodilation and hyperreactivity to phenylephrine, but arginine and training were capable of preventing these effects, even separately. Higher nitric oxide level was observed in the FA and FT groups, and no potentiating effect was detected. Thus, only training was able to prevent the increase in TAG and improve the protein mass, and training and arginine exert similar effects on fat content, insulin and endothelial function, but these effects are not additive.