AMPK activation: a therapeutic target for type 2 diabetes?

Whole exome sequencing uncovers rare variants associated with PCOS susceptibility in Indian women

Polycystic ovary syndrome (PCOS) is a complex polygenic endocrinopathy affecting 5-20% of reproductive-age women. Familial studies, candidate gene studies, and GWAS have identified multiple PCOS-associated genetic loci. This study aims to identify the functional variants associated with PCOS. We applied whole exome sequencing (WES) to identify functional variants among eighty-five well-characterized women with PCOS. The annotated variants were filtered based on minor allele frequency and in-silico pathogenicity prediction. We found a significant association of 234 rare pathogenic nonsynonymous variants in 201 genes with PCOS in our study group. These genes are linked to steroid hormone biosynthesis, ovarian steroidogenesis, insulin resistance, and PI3K-Akt signaling pathway which are influential in PCOS pathophysiology. Further, several rare variants were found to be unique to women with and without insulin resistance, and enrichment analysis revealed that carbohydrate and lipid metabolism was especially deranged in insulin-resistant PCOS women. Variants of the steroidogenesis pathway were validated by Sanger sequencing including rs368902124 (CYP19A1), rs143286842 (IGF1R), and rs555458296 (BMP-6). In-silico analysis by DUET showed that these variants destabilized the folding of their corresponding protein. Women carrying these rare variants presented with altered hormonal profiles and clinical signs of hyperandrogenism and hyperinsulinemia, emphasizing their impact on PCOS pathophysiology. Several functional rare variants have been revealed to be associated with increased PCOS risk in the present study thus, expanding the genetic susceptibility landscape of Indian women to PCOS.

Unlocking the multifaceted roles of GLP-1: Physiological functions and therapeutic potential

Glucagon (GCG) like peptide 1 (GLP-1) has emerged as a powerful player in regulating metabolism and a promising therapeutic target for various chronic diseases. This review delves into the physiological roles of GLP-1, exploring its impact on glucose homeostasis, insulin secretion, and satiety. We examine the compelling evidence supporting GLP-1 receptor agonists (GLP-1RAs) in managing type 2 diabetes (T2D), obesity, and other diseases. The intricate molecular mechanisms underlying GLP-1RAs are explored, including their interactions with pathways like extracellular signal-regulated kinase 1/2 (ERK1/2), activated protein kinase (AMPK), cyclic adenine monophosphate (cAMP), mitogen-activated protein kinase (MAPK), and protein kinase C (PKC). Expanding our understanding, the review investigates the potential role of GLP-1 in cancers. Also, microribonucleic acid (RNA) (miRNAs), critical regulators of gene expression, are introduced as potential modulators of GLP-1 signaling. We delve into the link between miRNAs and T2D obesity and explore specific miRNA examples influencing GLP-1R function. Finally, the review explores the rationale for seeking alternatives to GLP-1RAs and highlights natural products with promising GLP-1 modulatory effects.

Diabetic neuropathy: cutting-edge research and future directions

Diabetic neuropathy (DN) is a prevalent and debilitating complication of diabetes mellitus, significantly impacting patient quality of life and contributing to morbidity and mortality. Affecting approximately 50% of patients with diabetes, DN is predominantly characterized by distal symmetric polyneuropathy, leading to sensory loss, pain, and motor dysfunction, often resulting in diabetic foot ulcers and lower-limb amputations. The pathogenesis of DN is multifaceted, involving hyperglycemia, dyslipidemia, oxidative stress, mitochondrial dysfunction, and inflammation, which collectively damage peripheral nerves. Despite extensive research, disease-modifying treatments remain elusive, with current management primarily focusing on symptom control. This review explores the complex mechanisms underlying DN and highlights recent advances in diagnostic and therapeutic strategies. Emerging insights into the molecular and cellular pathways have unveiled potential targets for intervention, including neuroprotective agents, gene and stem cell therapies, and innovative pharmacological approaches. Additionally, novel diagnostic tools, such as corneal confocal microscopy and biomarker-based tests, have improved early detection and intervention. Lifestyle modifications and multidisciplinary care strategies can enhance patient outcomes. While significant progress has been made, further research is required to develop therapies that can effectively halt or reverse disease progression, ultimately improving the lives of individuals with DN. This review provides a comprehensive overview of current understanding and future directions in DN research and management.

Natural products targeting AMPK signaling pathway therapy, diabetes mellitus and its complications

Diabetes mellitus (DM) ranks among the most prevalent chronic metabolic diseases, characterized primarily by a persistent elevation in blood glucose levels. This condition typically stems from either insufficient insulin secretion or a functional defect in the insulin itself. Clinically, diabetes is primarily classified into type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), with T2DM comprising nearly 90% of all diagnosed cases. Notably, the global incidence of T2DM has surged dramatically over recent decades. The adenylate-activated protein kinase (AMPK) signaling pathway is crucial in regulating cellular energy metabolism, marking it as a significant therapeutic target for diabetes and related complications. Natural products, characterized by their diverse origins, multifaceted bioactivities, and relative safety, hold considerable promise in modulating the AMPK pathway. This review article explores the advances in research on natural products that target the AMPK signaling pathway, aiming to inform the development of innovative antidiabetic therapies.

Antin-diabetic cognitive dysfunction effects and underpinning mechanisms of phytogenic bioactive peptides: a review

Diabetic cognitive dysfunction is one of the important comorbidities and complications of diabetes, which is mainly manifested by loss of learning ability and memory, behavioural disorders, and may even develop into dementia. While traditional anti-diabetic medications are effective in improving cognition and memory, long-term use of these medications can be accompanied by undesirable side effects. Therefore, there is an urgent need to find safe and effective alternative therapies. Accumulating evidence suggests that phytogenic bioactive peptides play an important role in the regulation of cognitive dysfunction in diabetes. In this review, we explored the relationship between diabetes mellitus and cognitive dysfunction, and the potential and underlying mechanisms of plant-derived bioactive peptides to improve diabetic cognitive dysfunction. We found that plant-derived active peptides alleviate diabetic cognitive impairment by inhibiting key enzymes (e.g., α-glucosidase, α-amylase) to improve blood glucose levels and increase antioxidant activity, modulate inflammatory mediators, and address intestinal dysbiosis. In conclusion, plant-derived active peptides show strong potential to improve diabetic cognitive impairment.

Beneficial Effects of PIN1 Inhibition on Diabetes Mellitus: A Concise Review

Type 2 diabetes mellitus is a long-term medical illness in which the body either becomes resistant to insulin or fails to produce it sufficiently. Mostly, combinatorial therapy is required to control blood glucose levels. However, combinatorial therapy has detrimental side effects. The prevalence of the cases and subsequent increases in medical costs of the same intimidate human health globally. While there have been a lot of studies focused on developing diabetic regimens that work to lower blood glucose levels, their effectiveness is short-lived because of unfavorable side effects, such as weight gain and hypoglycemia. In recent years, the PIN1 (protein interacting with NIMA) enzyme has attracted the attention of researchers. Previous studies suggested that PIN1 may act on the various substrates that are involved in the progression of T2DM and also help in the management of diabetes-related disorders. Thus, the focus of the current review is to examine the correlation between PIN1, T2DM and its related disorders and explore the possibility of developing novel therapeutic targets through PIN1 inhibition.

Higher AMPK activation in mouse oxidative compared with glycolytic muscle does not correlate with LKB1 or CaMKKβ expression

AMP-activated protein kinase (AMPK) is an energy-sensing serine/threonine kinase involved in metabolic regulation. It is phosphorylated by the upstream liver kinase B1 (LKB1) or calcium/calmodulin-dependent kinase kinase 2 (CaMKKβ). In cultured cells, AMPK activation correlates with LKB1 activity. The phosphorylation activates AMPK, shifting metabolism toward catabolism and promoting mitogenesis. In muscles, inactivity reduces AMPK activation, shifting the phenotype of oxidative muscles toward a more glycolytic profile. Here, we compared the basal level of AMPK activation in glycolytic and oxidative muscles and analyzed whether this relates to LKB1 or CaMKKβ. Using Western blotting, we assessed AMPK expression and phosphorylation in soleus, gastrocnemius (GAST), extensor digitorum longus (EDL), and heart from C57BL6J mice. We also assessed LKB1 and CaMKKβ expression, and CaMKKβ activity in tissue homogenates. AMPK activation was higher in oxidative (soleus and heart) than in glycolytic muscles (gastrocnemius and EDL). This correlated with AMPK α1-isoform expression, but not LKB1 and CaMKKβ. LKB1 expression was sex dependent and lower in male than female muscles. CaMKKβ expression was very low in skeletal muscles and did not phosphorylate AMPK in muscle lysates. The higher AMPK activation in oxidative muscles is in line with the fact that activated AMPK maintains an oxidative phenotype. However, this could not be explained by LKB1 and CaMKKβ. These results suggest that the regulation of AMPK activation is more complex in muscle than in cultured cells. As AMPK has been proposed as a therapeutic target for several diseases, future research should consider AMPK isoform expression and localization, and energetic compartmentalization.NEW & NOTEWORTHY It is important to understand how AMP-activated kinase, AMPK, is regulated, as it is a potential therapeutic target for several diseases. AMPK is activated by liver kinase B1, LKB1, and calcium/calmodulin-dependent kinase kinase 2, CaMKKβ. In cultured cells, AMPK activation correlates with LKB1 expression. In contrast, we show that AMPK-activation was higher in oxidative than glycolytic muscle, without correlating with LKB1 or CaMKKβ expression. Thus, AMPK regulation is more complex in highly compartmentalized muscle cells.

The microbial metabolite imidazole propionate dysregulates bone homeostasis by inhibiting AMP-activated protein kinase (AMPK) signaling

Microbial metabolites provide numerous benefits to the human body but can also contribute to diseases such as obesity, diabetes, cancer, and bone disorders. However, the role of imidazole propionate (ImP), a histidine-derived metabolite produced by the intestinal microbiome, in bone metabolism and the development of osteoporosis is still poorly understood. In this study, we investigated the role of ImP and its underlying mechanisms in regulating bone homeostasis. When ImP was administered to 8-week-old mice for 4 weeks, bone loss was observed, along with a decrease in alkaline phosphatase-positive osteoblast cells. Additionally, bone marrow stromal cells (BMSCs) isolated from ImP-treated mice exhibited reduced osteogenic potential. In BMSCs from control mice, ImP treatment inhibited BMP2-induced osteoblast differentiation while promoting adipocyte differentiation. However, ImP had no effect on RANKL-induced osteoclast differentiation or activity in bone marrow macrophages. Mechanistically, ImP treatment increased p38γ phosphorylation and decreased AMPK (T172) phosphorylation in BMSCs. Suppression of p38γ expression using si-p38γ reversed the inhibitory effects of ImP on osteoblast differentiation, with a concurrent increase in AMPK (T172) phosphorylation. Conversely, ImP stimulated adipocyte differentiation by decreasing AMPK (T172) phosphorylation. Treatment with the AMPK agonist metformin significantly reversed the inhibitory effects of ImP on osteoblast differentiation and the promotion of adipocyte differentiation, along with enhanced AMPK (T172) phosphorylation. These findings suggest that the microbial metabolite ImP may disrupt bone homeostasis by stimulating p38γ phosphorylation and inhibiting the AMPK pathway, presenting a potential therapeutic target for managing metabolic bone diseases.

Ziziphus jujuba (Jujube) in Metabolic Syndrome: From Traditional Medicine to Scientific Validation

PURPOSE OF REVIEW

This review evaluates the therapeutic potential of Ziziphus jujuba and its main components in managing complications of metabolic syndrome, including diabetes, dyslipidemia, obesity, and hypertension.

RECENT FINDINGS

The reviewed studies provide evidence supporting the use of Z. jujuba and its main components (lupeol and betulinic acid) as natural treatments for complications of metabolic syndrome. These substances enhance glucose uptake through the activation of signaling pathways such as phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), reduce hepatic glucose synthesis, and increase glucose uptake by adipocytes and skeletal muscle cells. They also improve insulin sensitivity by modulating AMP-activated protein kinase (AMPK) activity and regulating insulin signaling proteins and glucose transporters. In the field of dyslipidemia, they inhibit triglyceride synthesis, lipid accumulation, and adipogenic enzymes, while influencing key signaling pathways involved in adipogenesis. Z. jujuba and its constituents demonstrate anti-adipogenic effects, inhibiting lipid accumulation and modulating adipogenic enzymes and transcription factors. They also exhibit positive effects on endothelial function and vascular health by enhancing endothelial nitric oxide synthase (eNOS) expression, NO production, and antioxidant enzyme activity. Z. jujuba, lupeol, and betulinic acid hold promise as natural treatments for complications of metabolic syndrome. They improve glucose metabolism, insulin sensitivity, and lipid profiles while exerting anti-adipogenic effects and enhancing endothelial function. However, further research is needed to elucidate the mechanisms and confirm their efficacy in clinical trials. These natural compounds offer potential as alternative therapies for metabolic disorders and contribute to the growing body of evidence supporting the use of natural medicines in their management.

Synergistic Interplay of Diet, Gut Microbiota, and Insulin Resistance: Unraveling the Molecular Nexus

This comprehensive review explores the intricate relationship between gut microbiota, diet, and insulin resistance, emphasizing the novel roles of diet-induced microbial changes in influencing metabolic health. It highlights how diet significantly influences gut microbiota composition, with different dietary patterns fostering diverse microbial communities. These diet-induced changes in the microbiome impact human metabolism by affecting inflammation, energy balance, and insulin sensitivity, particularly through microbial metabolites like short-chain fatty acids (SCFAs). Focusing the key mediators like endotoxemia and systemic inflammation, and introduces personalized microbiome-based therapeutic strategies, it also investigates the effects of dietary components-fiber, polyphenols, and lipids-on microbiota and insulin sensitivity, along with the roles of protein intake and amino acid metabolism. The study compares the effects of Western and Mediterranean diets on the microbiota-insulin resistance axis. Therapeutic implications, including probiotics, fecal microbiota transplantation (FMT), and personalized diets, are discussed. Key findings reveal that high-fat diets, especially those rich in saturated fats, contribute to dysbiosis and increased intestinal permeability, while high-fiber diets promote beneficial bacteria and SCFAs. The review underscores the future potential of food and microbiota interventions for preventing or managing insulin resistance.

Maternal swimming with overload allied to postnatal high-fat, high-sugar diet induce subtle impairment on rat offspring's ovarian redox homeostasis

Context The Developmental Origins of Health and Disease (DOHaD) concept suggests that early-life interventions significantly influence the long-term health outcomes of offspring. Emerging evidence supports that maternal physical exercise and balanced nutrition can positively impact the health of the next generation. Aims This study investigated the effects of maternal swimming combined with postnatal high-fat, high-sugar (HFHS) diet on the ovarian health of adult female Wistar rat offspring. Methods Adult female Wistar rats performed swimming exercise in a controlled temperature environment (32°C, 2% bodyweight overload adjusted daily) during 4weeks, starting 1week prior mating. The female offspring received a control or HFHS diet from postnatal day (PND) 21 to PND 90. We analyzed offspring's body weight, ovarian histomorphology, redox status, and associated molecular pathways 5' adenosine monophosphate-activated protein kinase (AMPKα), forkhead box O3 (FoxO3), and mitofusin 1 (Mfn-1). Key results Our findings reveal that maternal swimming exerted an effect on offspring body weight gain, delaying it. Individually, maternal exercise reduced superoxide dismutase (SOD) activity and mitofusin-1 levels, while the postnatal HFHS diet alone decreased both SOD and glutathione peroxidase (GPx) activities and increased the pFOXO3a/FOXO3a ratio in the ovaries. Conclusions We showed that combination of maternal swimming with a 2% overload and a postnatal HFHS diet can negatively affect the ovarian redox balance in offspring. Implications Prenatal and postnatal lifestyle might affect reproductive function in females.

Metformin Use and Vitamin B12 Deficiency in People with Type 2 Diabetes. What Are the Risk Factors? A Mini-systematic Review

Background and Aim: Metformin is recommended as the first-line agent for the management of type 2 diabetes following lifestyle and dietary changes. The long-term use of metformin has been associated with vitamin B12 deficiency. The aim of this review is to investigate the effect of metformin on vitamin B12 levels and identify any risk factors. Method: A literature search was conducted using MEDLINE, PubMed and ProQuest Central. Selected articles were peer-reviewed articles, written in English and published from 2015 and onwards. Excluded articles were case reports, reviews or meta-analyses, as well as those with no access to full text. Results: In total, 21 articles were included. There was a significant association between metformin use and vitamin B12 levels in 17 studies, while 4 studies found no such association. The risk factors examined were metformin dose, treatment duration, patient age and patient ethnicity. Conclusion: In summary, metformin use was associated with lower vitamin B12 concentrations, and higher doses and longer durations of treatment increase the risk of vitamin B12 deficiency. Routine vitamin B12 screening is recommended, prioritizing higher-risk patients. Further research is needed to identify when to initiate monitoring.

Deficiency of ADAR2 ameliorates metabolic-associated fatty liver disease via AMPK signaling pathways in obese mice

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease caused by hepatic steatosis. Adenosine deaminases acting on RNA (ADARs) catalyze adenosine to inosine RNA editing. However, the functional role of ADAR2 in NAFLD is unclear. ADAR2+/+/GluR-BR/R mice (wild type, WT) and ADAR2-/-/GluR-BR/R mice (ADAR2 KO) mice are fed with standard chow or high-fat diet (HFD) for 12 weeks. ADAR2 KO mice exhibit protection against HFD-induced glucose intolerance, insulin resistance, and dyslipidemia. Moreover, ADAR2 KO mice display reduced liver lipid droplets in concert with decreased hepatic TG content, improved hepatic insulin signaling, better pyruvate tolerance, and increased glycogen synthesis. Mechanistically, ADAR2 KO effectively mitigates excessive lipid production via AMPK/Sirt1 pathway. ADAR2 KO inhibits hepatic gluconeogenesis via the AMPK/CREB pathway and promotes glycogen synthesis by activating the AMPK/GSK3β pathway. These results provide evidence that ADAR2 KO protects against NAFLD progression through the activation of AMPK signaling pathways.

Lauric acid attenuates hepato-metabolic complications and molecular alterations in high-fat diet-induced nonalcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) has emerged as a major chronic liver illness characterized by increase of lipid content in the liver. This study investigated the role of lauric acid to treat NAFLD in male adult Sprague Dawley rats. In this study, to induce NAFLD in the rats, a high-fat diet (HFD) was administered for eight consecutive weeks. Lauric acid groups received lauric acid (250 and 500 mg/kg; orally), concurrently with HFD for eight consecutive weeks. Lauric acid could ameliorate the serum levels of TG, TC, ALT, AST, blood glucose, and insulin. Moreover, lauric acid significantly elevated the levels of SOD, GSH, catalase, and IL-10. Additionally, it lowered the hepatic levels of MDA, ROS, MPO, 4-HNE, interleukin (IL)-1β, and tumor necrosis factor (TNF-α). Furthermore, lauric acid significantly up-regulated the hepatic expression of IRS1, AMPK, PI3K, and SIRT1 genes. In parallel, lauric acid could improve the histopathological picture of the liver and reduce the liver apoptosis via decreasing the expression of annexin V (Anx V). Finally, our data proposed that lauric acid could be an effective candidate for the NAFLD treatment.

The Active Ingredient Catalpol in Rehmannia glutinosa Reduces Blood Glucose in Diabetic Rats via the AMPK Pathway

Background

Type 2 diabetes mellitus (T2DM) poses a huge threat to population health globally, and more drugs need to be explored for treatment. In this study, we investigated the mechanism of active ingredient catalpol in Rehmannia glutinosa on reduces blood glucose in diabetic.

Methods

The T2DM model was constructed by intraperitoneal injection of streptozotocin into Sprague-Dawley (SD) rats, which were randomly grouped into diabetes model group, pioglitazone group, Rehmannia glutinosa group, catalpol high-dose group, catalpol low-dose group and normal control group.The intervention was continued for 28 d, and changes in body weight, fasting blood glucose, insulin and lipid levels were observed.

Results

Of all the drugs, pioglitazone had the most pronounced hypoglycemic effect, which began to decline after 2 weeks of treatment in the low-dose catalpol group and had no hypoglycemic effect in the high-dose catalpol group. Among them, Rehmannia glutinosa was able to increase serum triglyceride level, and pioglitazone effectively reduced total cholesterol level in rats. The low dose of catalpol decreased the concentration of low-density lipoprotein cholesterol (LDL), while the high dose of catalpol increased the concentration of LDL.

Conclusion

As an active ingredient in Rehmannia glutinosa, catalpol has the potential to lower blood glucose and improve blood lipids in diabetes treatment, and its action may be achieved by regulating the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway, which provides a new idea for the development of new diabetes therapeutic approaches.

Antidiabetic features of AdipoAI, a novel AdipoR agonist

Adiponectin is an antidiabetic endogenous adipokine that plays a protective role against the unfavorable metabolic sequelae of obesity. Recent evidence suggests a sinister link between hypoadiponectinemia and development of insulin resistance/type 2 diabetes (T2D). Adiponectin's insulin-sensitizing property is mediated through the specific adiponectin receptors R1 and R2, which activate the AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR) α pathways. AdipoAI is a novel synthetic analogue of endogenous adiponectin with possibly similar pharmacological effects. Thus, there is a need of orally active small molecules that activate Adipoq subunits, and their downstream signaling, which could ameliorate obesity related type 2 diabetes. In the study we aim to investigate the effects of AdipoAI on obesity and T2D. Through in-vitro and in-vivo analyses, we investigated the antidiabetic potentials of AdipoAI and compared it with AdipoRON, another orally active adiponectin receptors agonist. Our results showed that in-vitro treatment of AdipoAI (0-5 µM) increased adiponectin receptor subunits AdipoR1/R2 with increase in AMPK and APPL1 protein expression in C2C12 myotubes. Similarly, in-vivo, oral administration of AdipoAI (25 mg/kg) observed similar effects as that of AdipoRON (50 mg/kg) with improved control of blood glucose and insulin sensitivity in diet-induced obesity (DIO) mice models. Further, AdipoAI significantly reduced epididymal fat content with decrease in inflammatory markers and increase in PPAR-α and AMPK levels and exhibited hepatoprotective effects in liver. Further, AdipoAI and AdipoRON also observed similar results in adipose tissue. Thus, our results suggest that low doses of orally active small molecule agonist of adiponectin AdipoAI can be a promising therapeutic target for obesity and T2D.

Emerging therapeutic options in the management of diabetes: recent trends, challenges and future directions

Diabetes is a serious health issue that causes a progressive dysregulation of carbohydrate metabolism due to insufficient insulin hormone, leading to consistently high blood glucose levels. According to the epidemiological data, the prevalence of diabetes has been increasing globally, affecting millions of individuals. It is a long-term condition that increases the risk of various diseases caused by damage to small and large blood vessels. There are two main subtypes of diabetes: type 1 and type 2, with type 2 being the most prevalent. Genetic and molecular studies have identified several genetic variants and metabolic pathways that contribute to the development and progression of diabetes. Current treatments include gene therapy, stem cell therapy, statin therapy, and other drugs. Moreover, recent advancements in therapeutics have also focused on developing novel drugs targeting these pathways, including incretin mimetics, SGLT2 inhibitors, and GLP-1 receptor agonists, which have shown promising results in improving glycemic control and reducing the risk of complications. However, these treatments are often expensive, inaccessible to patients in underdeveloped countries, and can have severe side effects. Peptides, such as glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), are being explored as a potential therapy for diabetes. These peptides are postprandial glucose-dependent pancreatic beta-cell insulin secretagogues and have received much attention as a possible treatment option. Despite these advances, diabetes remains a major health challenge, and further research is needed to develop effective treatments and prevent its complications. This review covers various aspects of diabetes, including epidemiology, genetic and molecular basis, and recent advancements in therapeutics including herbal and synthetic peptides.

Network pharmacology combined with molecular docking and experimental verification to elucidate functional mechanism of Fufang Zhenzhu Tiaozhi against type 2 diabetes mellitus

Fufang Zhenzhu Tiaozhi (FTZ) capsules have been prescribed for treating glucose and lipid metabolism disorders such as type 2 diabetes mellitus (T2DM). However, the underlying mechanism remains unknown. In this study, network pharmacology and experimental verification were combined to investigate the mechanisms of FTZ in treating T2DM. A total of 176 active ingredients and 1169 corresponding targets were screened using biological databases. 598 potential targets of T2DM were retrieved from GeneCards, PharmGKB, OMIM, Drugbank, and TTD. The Venn diagram was employed to identify the 194 intersection targets, which were employed to construct the "Herb-Compound-Target" interacting networks. These common targets were also used to prepare a protein-protein interaction (PPI) network to uncover potential targets. The four core targets were docked to their corresponding targets for binding analysis. Additionally, the top-ranked poses of ingredients and the positive compounds from each protein were evaluated for stability using molecular dynamics. Our results suggest that core active ingredients such as kaempferol, luteolin, and baicalein have high binding affinity and stability with AKT1, PTGS2 (also known as COX-2), DPP4, and PAPRG. GO and KEGG analyses indicated that the treatment T2DM by FTZ might be related to different pathway like AMPK and EGFR pathways. The experimental validation results proved that kaempferol, luteolin, and baicalein could significantly inhibit the activity of DPP4 and COX-2, kaempferol and luteolin were also able to activate AKT and AMPK signaling pathway. This study further validated previous findings and enhanced our understanding of the potential effects of FTZ on T2DM.Communicated by Ramaswamy H. Sarma.

Virtual screening, molecular docking, molecular dynamics, and MM-GBSA approaches identify prospective fructose-1,6-bisphosphatase inhibitors from pineapple for diabetes management

Diabetes affects millions globally and poses treatment challenges. Targeting the enzyme fructose-1,6-bisphosphatase (FBPase) in gluconeogenesis and exploring plant-based therapies offer potential solutions for improving diabetes management while supporting sustainability and medicinal advancements. Utilizing pineapple (Ananas comosus L. Merr.) waste as a source of drug precursors could be valuable for health and environmental care due to its medicinal benefits and abundant yearly biomass production. Therefore, this study conducted a virtual screening to identify potential natural compounds from pineapple that could inhibit FBPase activity. A total of 112 compounds were screened for drug-likeness and ADMET properties, and molecular docking simulations were performed on 20 selected compounds using blind docking. The lead compound, butane-2,3-diyl diacetate, was subjected to 100 ns MD simulations, revealing a binding energy of -5.4 kcal/mol comparable to metformin (-5.6 kcal/mol). The MD simulation also confirmed stable complexes with crucial hydrogen bonds. Glu20, Ala24, Thr27, Gly28, Glu29, Leu30, Val160, Met177, Asp178, and Cys179 were identified as key amino acids that stabilized the human liver FBPase-butane-2,3-diyl diacetate complex, while Tyr215 and Asp218 played a crucial role in the human liver FBPase-Metformin complex. Our study indicates that the lead compound has high intestinal solubility. Therefore, it would show rapid bloodstream distribution and effective action on the target protein, making butane-2,3-diyl diacetate a potential antidiabetic drug candidate. However, further investigations in vitro, preclinical, and clinical trials are required to thoroughly assess its efficacy and safety.Communicated by Ramaswamy H. Sarma.

Antioxidant, anti-inflammatory, hypoglycemic, and anti-hyperglycemic activity of chickpea protein hydrolysates evaluated in BALB-c mice

Chickpea (ICC3761) protein hydrolysates have shown high in vitro antioxidant activity (AoxA) and antidiabetic potential. The aim of this study was to evaluate the in vivo activities (i.e., antioxidant, anti-inflammatory, hypoglycemic, and anti-hyperglycemic) of chickpea albumin hydrolysates (CAH) obtained with alcalase and pepsin-pancreatin (fractions ≤ 10 kDa). The CAH were analyzed for degree of hydrolysis (DH), electrophoretic and chromatographic profiles, and in vitro AoxA (2,2'-azino-bis(3-ethylbenzothiazolin)-6-sulfonic acid [ABTS], 2,2-diphenyl-1-pycrilhydrazyl [DPPH]). They were also evaluated for AoxA, anti-inflammatory and hypo- and anti-hyperglycemic activities in BALB-c mice. The DH was 20% for the alcalase CAH and 50% for the pepsin-pancreatin CAH, while the AoxA by ABTS (1 mg/mL) was 64.8% and 64.9% and by DPPH (5 mg/mL) was 48.0% and 31.1%. In the in vivo AoxA assay, mice of non-damaged control and those treated with both CAH showed similar alkaline phosphatase values, control and pepsin-pancreatin treated groups had similar malondialdehyde levels, while treated and non-damaged control groups had higher glutathione levels than the damaged control. Liver histopathology revealed that the pepsin-pancreatin CAH mitigated most of the pathological changes associated with the induced oxidative damage. Both CAH (2 mg/ear) reduced croton oil-induced ear edema in mice. The α-glucosidase inhibition of CAH (100 mg/mL) was 31.1% (alcalase) and 52.4% (pepsin-pancreatin). Mice treated with alcalase CAH (100 mg/mL) and glibenclamide exhibited similar hypoglycemic activities, whereas only those treated with the pepsin-pancreatin CAH (200 mg/kg body weight) showed anti-hyperglycemic activity. The results indicate that CAH can be used as a source of bioactive peptides with antioxidant, anti-inflammatory, hypoglycemic, and anti-hyperglycemic activities.

Glycyrrhizic Acid Protects Glomerular Podocytes Induced by High Glucose by Modulating SNARK/AMPK Signaling Pathway

OBJECTIVE

Diabetic nephropathy is one of the most important microvascular complications of diabetes, which mainly refers to glomerular capillary sclerosis. Podocytes are an important part of glomerular capillaries. Previous clinical and basic studies have shown that fibrosis is the main factor of diabetic nephropathy. This study aimed to assess the protective mechanism of glycyrrhizic acid (GA) on glomerular podocytes induced by high glucose as we hypothesized that GA may have antifibrotic and anti-inflammatory effects on podocytes through regulation of the adenosine 5'-monophosphate-activated protein kinase (AMPK)/sucrose nonfermenting AMPK-related kinase (SNARK) signaling pathway.

METHODS

SNARK siRNA was used to transfect podocytes. Real-time quantitative polymerase chain reaction and immunofluorescence staining assays were used for molecular and pathological analysis. The expression levels of key pathway proteins (including TGF-β1, α-SMA, SITR1, AMPKα, LKB1, PGC-1α, NF-κB, IL-6, and TNF-α) were verified by Western blotting. The expression of inflammatory factors in podocytes was detected by ELISA.

RESULTS

We demonstrated that GA decreased the expression of podocyte fibrosis signaling pathway-related factors by upregulating the AMPK pathway and its related factors. However, after transfection of podocytes with SNARK siRNA, there was an increased expression of fibrosis-related factors and inflammation-related factors.

CONCLUSION

GA can protect podocytes and alleviate fibrosis and inflammation induced by high glucose, which is related to the AMPK signaling pathway. Meanwhile, knockdown of SNARK protein can inhibit the AMPK signaling pathway, aggravate fibrosis, and increase inflammation.

The role of apelinergic system in metabolism and reproductive system in normal and pathological conditions: an overview

Lifestyle changes have made metabolic disorders as one of the major threats to life. Growing evidence demonstrates that obesity and diabetes disrupt the reproductive system by affecting the gonads and the hypothalamus-pituitary-gonadal (HPG) axis. Apelin, an adipocytokine, and its receptor (APJ) are broadly expressed in the hypothalamus nuclei, such as paraventricular and supraoptic, where gonadotropin-releasing hormone (GnRH) is released, and all three lobes of the pituitary, indicating that apelin is involved in the control of reproductive function. Moreover, apelin affects food intake, insulin sensitivity, fluid homeostasis, and glucose and lipid metabolisms. This review outlined the physiological effects of the apelinergic system, the relationship between apelin and metabolic disorders such as diabetes and obesity, as well as the effect of apelin on the reproductive system in both gender. The apelin-APJ system can be considered a potential therapeutic target in the management of obesity-associated metabolic dysfunction and reproductive disorders.

Mitochondrial ATP synthase as a direct molecular target of chromium(III) to ameliorate hyperglycaemia stress

Chromium(III) is extensively used as a supplement for muscle development and the treatment of diabetes mellitus. However, its mode of action, essentiality, and physiological/pharmacological effects have been a subject of scientific debate for over half a century owing to the failure in identifying the molecular targets of Cr(III). Herein, by integrating fluorescence imaging with a proteomic approach, we visualized the Cr(III) proteome being mainly localized in the mitochondria, and subsequently identified and validated eight Cr(III)-binding proteins, which are predominately associated with ATP synthesis. We show that Cr(III) binds to ATP synthase at its beta subunit via the catalytic residues of Thr213/Glu242 and the nucleotide in the active site. Such a binding suppresses ATP synthase activity, leading to the activation of AMPK, improving glucose metabolism, and rescuing mitochondria from hyperglycaemia-induced fragmentation. The mode of action of Cr(III) in cells also holds true in type II diabetic male mice. Through this study, we resolve the long-standing question of how Cr(III) ameliorates hyperglycaemia stress at the molecular level, opening a new horizon for further exploration of the pharmacological effects of Cr(III).

Therapeutic effects of icariin and icariside II on diabetes mellitus and its complications

Diabetes mellitus (DM) is a global health issue in the twenty-first century, and there are numerous challenges in preventing and alleviating its chronic complications. The herb Epimedium has beneficial therapeutic effects on various human diseases, including DM. Its major flavonoid component, icariin, has significant anti-DM activity and may help improve pancreatic β-cell dysfunction and insulin resistance. Furthermore, preclinical evidence has shown that icariin and its in vivo bioactive form, icariside II, have preventive and therapeutic effects on several diabetic complications, including diabetic cardiomyopathy, diabetic vascular endothelial disorder, diabetic nephropathy, and diabetic erectile dysfunction. In this review, we present the general and toxicological information concerning icariin and icariside II and review the anti-DM effects of icariin from a molecular perspective. Additionally, we discuss the potential benefits of icariin and icariside II on the important pathological mechanisms of various diabetic complications. Despite positive preclinical evidence, additional investigations are needed before relevant clinical studies can be conducted. Therefore, we conclude with suggestions for future research. Hopefully, this review will provide a comprehensive molecular perspective for future research and product development related to icariin and icariside II in treating DM and diabetic complications.

The glucotoxicity protecting effect of honokiol in human hepatocytes via directly activating AMPK

Introduction

Sustained hyperglycemia causes glucotoxicity, which has been regarded as a contributor to hepatocyte damage in type 2 diabetes (T2D) and its metabolic comorbidities. Honokiol is a natural biphenolic component derived from the dietary supplement Magnolia officinalis extract. This study aimed to investigate the effects of honokiol on glucose metabolism disorders and oxidative stress in hepatocytes and the underlying mechanisms.

Methods

HepG2 cells were treated with glucosamines (18 mM) to induce glucotoxicity as a diabetic complication model in vitro.

Results and discussion

Honokiol significantly increased glucose consumption, elevated 2-NBDG uptake, and promoted GLUT2 translocation to the plasma membrane in glucosamine-treated HepG2 cells, indicating that honokiol ameliorates glucose metabolism disorders. Furthermore, glucosamine-induced ROS accumulation and loss of mitochondrial membrane potential were markedly reduced by honokiol, suggesting that honokiol alleviated glucotoxicity-induced oxidative stress. These effects were largely abolished by compound C, an AMPK inhibitor, suggesting an AMPK activation-dependent manner of honokiol function in promoting glucose metabolism and mitigating oxidative stress. Molecular docking results revealed that honokiol could interact with the amino acid residues (His151, Arg152, Lys243, Arg70, Lys170, and His298) in the active site of AMPK. These findings provide new insights into the antidiabetic effect of honokiol, which may be a promising agent for the prevention and treatment of T2D and associated metabolic comorbidities.

Heliciopsides A-E, Unusual Macrocyclic and Phenolic Glycosides from the Leaves of Heliciopsis terminalis and Their Stimulation of Glucose Uptake

Ten phenolic constituents, including three new macrocyclic glycosides (1-3), a new phenolic glycoside (5), a new biphenyl glycoside (6), and five known compounds (4, 7-10), were isolated from a 70% MeOH extract of the leaves of Heliciopsis terminalis by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-guided molecular networking. The chemical structures of new compounds 1-3, 5 and 6 were established based on comprehensive spectroscopic data analysis, including 1D and 2D NMR and HRESIMS techniques. All isolated compounds (1-10) were evaluated for their stimulation of glucose uptake in differentiated 3T3-L1 adipocytes using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a fluorescent glucose analog. Compounds 3, 6 and 8 showed stimulatory effects on the uptake of 2-NBDG in 3T3-L1 adipocyte cells. Among them, compounds 3 and 6 activated the AMPK signaling pathway in differentiated C2C12 myoblasts.

Therapeutic Antiaging Strategies

Aging constitutes progressive physiological changes in an organism. These changes alter the normal biological functions, such as the ability to manage metabolic stress, and eventually lead to cellular senescence. The process itself is characterized by nine hallmarks: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. These hallmarks are risk factors for pathologies, such as cardiovascular diseases, neurodegenerative diseases, and cancer. Emerging evidence has been focused on examining the genetic pathways and biological processes in organisms surrounding these nine hallmarks. From here, the therapeutic approaches can be addressed in hopes of slowing the progression of aging. In this review, data have been collected on the hallmarks and their relative contributions to aging and supplemented with in vitro and in vivo antiaging research experiments. It is the intention of this article to highlight the most important antiaging strategies that researchers have proposed, including preventive measures, systemic therapeutic agents, and invasive procedures, that will promote healthy aging and increase human life expectancy with decreased side effects.

The Antibody Response to the BNT162b2 mRNA COVID-19 Booster in Healthcare Workers: Association between the IgG Antibody Titers and Anthropometric and Body Composition Parameters

BACKGROUND

Research shows that in most people, two-dose vaccination helps to shape the humoral response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Further studies are required to learn about the vaccine's effectiveness after boosting.

METHODS

We conducted a prospective study among 103 healthcare workers (HCWs) from a regional multi-specialty hospital vaccinated with three doses of the BNT162b2 vaccine. We compared their immunoglobulin G (IgG) titers 14 days after the second dose with those 21 days after the booster. We also compared their anthropometric and body composition parameters with IgG concentrations at the same time points.

RESULTS

Twenty-one days after the booster, all study participants were seropositive. Their mean IgG antibody titers were significantly lower than 14 days after the second dose (158.94 AU/mL ± 90.34 AU/mL vs. 505.79 AU/mL ± 367.16 AU/mL). Post-booster Spearman's correlation analysis showed a significantly weak correlation between the IgG antibody titer and parameters related to muscle tissue and adipose tissue (including body fat mass).

CONCLUSIONS

The BNT162b2 booster stimulates the humoral response to a lesser extent than the two-dose BNT162b2 primary vaccination. The adipose and muscle tissue parameters show a weak positive correlation with the SARS-CoV-2 IgG antibody titers.

Effects of Physical Exercise on Mitochondrial Biogenesis of Skeletal Muscle Modulated by Histones Modifications in Type 2 Diabetes

Epigenetic modification in skeletal muscle induced by environmental factors seems to modulate several metabolic pathways that underlie Type 2 Diabetes Mellitus (T2DM) development. Mitochondrial biogenesis is an important process for maintaining lipid metabolism homeostasis, as well as epigenetic modifications in proteins that regulate this pathway have been observed in the skeletal muscle of T2DM subjects. Moreover, physical exercise affects several metabolic pathways attenuating metabolic deregulation observed in T2DM. The pathways that regulate mitochondrial homeostasis are one of the key components for understanding such physical exercise beneficial effects. Thus, in this study, we investigate the epigenetic mechanisms underlying mitochondrial biogenesis in the skeletal muscle in T2DM, focusing on histone modifications and the possible mechanisms by which physical exercise delay or inhibit T2DM onset. The results indicate that exercise promotes improvements in cellular metabolism through increasing enzymes of the antioxidant system, AMPK and ATP-citrate lyase activity, Acetyl-CoA concentration, and enhancing the acetylation of histones. A key mediator of mitochondrial biogenesis such as peroxisome proliferator-activated receptor γ coactivator-1α (PGC1) seems to be upregulated by exercise in T2DM and such factor positively regulates the skeletal muscle mitochondrial biogenesis, which improves energy metabolism and glucose homeostasis inhibiting or delaying insulin resistance and further T2DM. 

Chlorella unsaturated fatty acids suppress high-fat diet-induced obesity in C57/BL6J mice

Chlorella has been identified as a rich source of unsaturated fatty acids. Since the antiobesity effects of unsaturated fatty acids have been well documented; therefore, we explored the antiobesity actions of chlorella unsaturated fatty acids (C.UFAs) in the current study. The obtained results demonstrated C.UFAs, which contain abundant linoleic acid, could retard body weight gain (reducing body weigh by 13.93% after 16 weeks of treatment), improve blood glucose (19.29% lower) and lipid profile (23.45% lower in TG, 8.76% lower in TC) compared to high-fat diet-fed C57BL/6J mice. The possible underlying mechanisms might involve reducing hepatic lipid accumulation via down-regulation of lipogenic genes (PPARγ, C/EBPα, LPL, aP2, FAS, and SREBP-1c) and up-regulation of lipolytic gene (adiponectin). We also demonstrate C.UFAs could reduce HFD-induced adipocyte hypertrophy via activation of AMPK signaling pathway in adipose tissue and liver. In summary, our study highlights the potential of C.UFAs as a functional food for obesity management. PRACTICAL APPLICATION: Chlorella has already been commercialized as a functional food antiobesity function. In the current study, the unsaturated fatty acids isolated from chlorella were found to exert beneficial effects on hyperglycemia, hyperlipidemia, hepatic steatosis, and adipocyte hypertrophy in high-fat diet-fed mice. This may provide theoretical foundation for developing novel chlorella-based functional foods.

17β-Estradiol Treatment Improves Acetylcholine-Induced Relaxation of Mesenteric Arteries in Ovariectomized UC Davis Type 2 Diabetes Mellitus Rats in Prediabetic State

We recently reported sex differences in mesenteric arterial function of the UC Davis type-2 diabetes mellitus (UCD-T2DM) rats as early as the prediabetic state. We reported that mesenteric arteries (MA) from prediabetic male rats exhibited a greater impairment compared to that in prediabetic females. However, when females became diabetic, they exhibited a greater vascular dysfunction than males. Thus, the aim of this study was to investigate whether the female sex hormone, estrogen preserves mesenteric arterial vasorelaxation in UCD-T2DM female rats at an early prediabetic state. Age-matched female Sprague Dawley and prediabetic (PD) UCD-T2DM rats were ovariectomized (OVX) and subcutaneously implanted with either placebo or 17β-estradiol (E_2, 1.5 mg) pellets for 45 days. We assessed the contribution of endothelium-derived relaxing factors (EDRF) to acetylcholine (ACh)-induced vasorelaxation, using pharmacological inhibitors. Responses to sodium nitroprusside (SNP) and phenylephrine (PE) were also measured. Additionally, metabolic parameters and expression of some targets associated with vascular and insulin signaling were determined. We demonstrated that the responses to ACh and SNP were severely impaired in the prediabetic state (PD OVX) rats, while E₂ treatment restored vasorelaxation in the PD OVX + E₂. Moreover, the responses to PE was significantly enhanced in MA of PD OVX groups, regardless of placebo or E₂ treatment. Overall, our data suggest that 1) the impairment of ACh responses in PD OVX rats may, in part, result from the elevated contractile responses to PE, loss of contribution of endothelium-dependent hyperpolarization (EDH) to vasorelaxation, and a decreased sensitivity of MA to nitric oxide (NO), and 2) the basis for the protective effects of E₂ may be partly attributed to the elevation of the NO contribution to vasorelaxation and its interaction with MA as well as potential improvement of insulin signaling. Here, we provide the first evidence of the role of E₂ in protecting MA from early vascular dysfunction in prediabetic female rats.

SGLT2 inhibitors: a focus on cardiac benefits and potential mechanisms

This paper highlights the cardioprotective potential of sodium-glucose cotransporter 2 inhibitors (SLGT2i), as well as several most discussed mechanisms responsible for their cardioprotection. Cardiovascular diseases are considered a primary cause of death in nearly 80% of type 2 diabetes mellitus (T2DM) patients, with a 2-4-fold greater incidence of heart failure (HF) among diabetics. As novel hypoglycemics, SGLT2i showed exceptional cardiovascular benefits, reflected through robust reductions of cardiovascular mortality and hospitalization for HF in T2DM patients. Recently, those effects have been reported even in patients with HF and reduced ejection fraction irrespectively of diabetic status, suggesting that cardioprotective effects of SGLT2i are driven independently of their hypoglycemic actions. SGLT2i exerted hemodynamic and metabolic effects, partially driven by natriuresis and osmotic diuresis. However, those systemic effects are modest, and therefore cannot be completely related to the cardiac benefits of these agents in T2DM patients. Hence, increased circulating ketone levels during SGLT2i administration have brought out another hypothesis of a cardiac metabolic switch. Moreover, SGLT2i influence ion homeostasis and exert anti-inflammatory and antifibrotic effects. Their enviable influence on oxidative stress markers, as well as anti- and pro-apoptotic factors, have also been reported. However, since the main mechanistical contributor of their cardioprotection has not been elucidated yet, a joint action of systemic and molecular mechanisms has been suggested. In the light of ongoing trials evaluating the effects of SGLT2i in patients with HF and preserved ejection fraction, a new chapter of beneficial SGLT2i mechanisms is expected, which might resolve their main underlying action.

Effect of berberine in comparison to metformin on the biophysical and biochemical parameters in diabetic albino Wistar rats

Introduction: Diabetic endothelial dysfunction is accompanied by increased oxidative stress and upregulated proinflammatory and inflammatory mediators in the endothelial vasculature. Aim of this study is to investigate the effect of Berberine, a natural alkaloid, on the oxidative stress, inflammation and its anti-oxidant effect in streptozotocin diabetic rats and to compare the effectiveness of FF with that of Metformin (Met) Material & Methods: This experimental animal study was conducted at animal house. The sample size included 174 albino wistar rats divided into 3 Groups, one control groups (C) Diabetic and untreated and two test groups. T1 Diabetic and treated with metformin 75 mg/kgwt/day) and T2 (T – Diabetics treated with Berberine(Ber) 100 mg/kgwt/day), with 58 rats in each group (29 male & 29 female). All the rats were treated with streptozotocin intra peritoneally and the diabetic state was induced.  T1 group was treated with metformin 75 mg/kg/wt/day. The T2 group of rats were treated with Berberine at a dose of 100 mg/kgwt/day. Blood sample was drawn from retro orbital plexus of animals and the biophysical and biochemical parameters were tested at an interval of 3, 6 and 12-months duration.

Transcriptomic profile of longissimus thoracis associated with fatty acid content in Nellore beef cattle

The beef fatty acid (FA) profile has the potential to impact human health, and displays polygenic and complex features. This study aimed to identify the transcriptomic FA profile in the longissimus thoracis muscle in Nellore beef cattle finished in feedlot. Forty-four young bulls were sampled to assess the beef FA profile by considering 14 phenotypes and including differentially expressed genes (DEG), co-expressed (COE), and differentially co-expressed genes (DCO) analyses. All samples (n = 44) were used for COE analysis, whereas 30 samples with extreme phenotypes for the beef FA profile were used for DEG and DCO. A total of 912 DEG were identified, and the polyunsaturated (n = 563) and unsaturated ω-3 (n = 346) FA sums groups were the most frequently observed. The COE analyses identified three modules, of which the blue module (n = 1776) was correlated with eight of 14 FA phenotypes. Also, 759 DCO genes were listed, and the oleic acid (n = 358) and monounsaturated fatty acids sum (n = 120) were the most frequent. Furthermore, 243 and 13, 319 and seven, and 173 and 12 gene ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways were enriched respectively for the DEG, COE, and DCO analyses. Combining the results, we highlight the unexplored GIPC2, ASB5, and PPP5C genes in cattle. Besides LIPE and INSIG2 genes in COE modules, the ACSL3, ECI1, DECR2, FITM1, and SDHB genes were signaled in at least two analyses. These findings contribute to understand the genetic mechanisms underlying the beef FA profile in Nellore beef cattle finished in feedlot.

Metformin Inhibits Na+/H+ Exchanger NHE3 Resulting in Intestinal Water Loss

Glycemic control is the key to the management of type 2 diabetes. Metformin is an effective, widely used drug for controlling plasma glucose levels in diabetes, but it is often the culprit of gastrointestinal adverse effects such as abdominal pain, nausea, indigestion, vomiting, and diarrhea. Diarrhea is a complex disease and altered intestinal transport of electrolytes and fluid is a common cause of diarrhea. Na+/H+ exchanger 3 (NHE3, SLC9A3) is the major Na+ absorptive mechanism in the intestine and our previous study has demonstrated that decreased NHE3 contributes to diarrhea associated with type 1 diabetes. The goal of this study is to investigate whether metformin regulates NHE3 and inhibition of NHE3 contributes to metformin-induced diarrhea. We first determined whether metformin alters intestinal water loss, the hallmark of diarrhea, in type 2 diabetic db/db mice. We found that metformin decreased intestinal water absorption mediated by NHE3. Metformin increased fecal water content although mice did not develop watery diarrhea. To determine the mechanism of metformin-mediated regulation of NHE3, we used intestinal epithelial cells. Metformin inhibited NHE3 activity and the effect of metformin on NHE3 was mimicked by a 5'-AMP-activated protein kinase (AMPK) activator and blocked by pharmacological inhibition of AMPK. Metformin increased phosphorylation and ubiquitination of NHE3, resulting in retrieval of NHE3 from the plasma membrane. Previous studies have demonstrated the role of neural precursor cell expressed, developmentally down-regulated 4-2 (Nedd4-2) in regulation of human NHE3. Silencing of Nedd4-2 mitigated NHE3 inhibition and ubiquitination by metformin. Our findings suggest that metformin-induced diarrhea in type 2 diabetes is in part caused by reduced Na+ and water absorption that is associated with NHE3 inhibition, probably by AMPK.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Therapeutic Role of Antimicrobial Peptides in Diabetes Mellitus

Antimicrobial peptides (AMPs) have recently become widely publicized because they have the potential to function in alternative therapies as “natural” antibiotics, with their main advantage being a broad spectrum of activity. The potential for antimicrobial peptides to treat diabetes mellitus (DM) has been reported. In diabetes mellitus type I (T1D), cathelicidin-related antimicrobial peptide (CRAMP), cathelicidin antimicrobial peptide (CAMP) and mouse-β- defensin 14 (mBD14) are positively affected. Decreased levels of LL-37 and human neutrophil peptide 1-3 (HNP1-3) have been reported in diabetes mellitus type II (T2D) relative to healthy patients. Moreover, AMPs from amphibians and social wasps have antidiabetic effects. In infections occurring in patients with tuberculosis-diabetes or diabetic foot, granulysin, HNP1, HNP2, HNP3, human beta-defensin 2 (HBD2), and cathelicidins are responsible for pathogen clearance. An interesting alternative is also the use of modified M13 bacteriophages containing encapsulated AMPs genes or phagemids.

Evaluation of hypoglycemic therapeutics and nutritional supplementation for type 2 diabetes mellitus management: An insight on molecular approaches

OBJECTIVE

This review aims to summarize the current management of type 2 diabetes principles, including oral hypoglycemic agents, types of insulin administration, diet maintenance, and various molecular approaches.

METHODS

A literature search was conducted in different databases such as Scopus, ScienceDirect, Google Scholar, and Web of Science by using the following keywords: type-2 diabetes mellitus (T2DM), first-line and second-line treatment, oral hypoglycemic agents, insulin administration, diet/nutritional therapy, gene and stem cell therapy, and diabetic complications.

RESULTS

The first-line treatment of T2DM includes administering oral hypoglycemic agents (OHAs) and second-line treatment by insulin therapy and some OHAs like Sulfonylurea's (SU). The oral hypoglycemic or oral antidiabetic drugs have the function of lowering glucose in the blood. Insulin therapy is recommended for people with A1C levels > 7.0, and insulin administration is evolved drastically from the syringe, pump, pen, inhalation, insulin jet, and patch. The use of OHAs and insulin therapy during glycemic control has a severe effect on weight gain and other side effects. Hence, diet maintenance (macro and micronutrients) and nutritional therapy guidelines were also reviewed/recommended for safe T2DM management. Besides, the recent progress in molecular approaches that focuses on identifying new targets for T2DM (i.e.) consisting of gene therapy, stem cell therapy, and the modulation of insulin signaling pathways for the regulation of glucose storage and uptake also discussed.

CONCLUSION

The analysis of all these key factors is necessary to develop a potential agent to cure T2DM and suggest that a combination of therapies will pave the way for advanced management of T2DM.

Metabolism and Health Effects of Rare Sugars in a CACO-2/HepG2 Coculture Model

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease worldwide and is impacted by an unhealthy diet with excessive calories, although the role of sugars in NAFLD etiology remains largely unexplored. Rare sugars are natural sugars with alternative monomers and glycosidic bonds, which have attracted attention as sugar replacers due to developments in enzyme engineering and hence an increased availability. We studied the impact of (rare) sugars on energy production, liver cell physiology and gene expression in human intestinal colorectal adenocarcinoma (Caco-2) cells, hepatoma G2 (HepG2) liver cells and a coculture model with these cells. Fat accumulation was investigated in the presence of an oleic/palmitic acid mixture. Glucose, fructose and galactose, but not mannose, l-arabinose, xylose and ribose enhanced hepatic fat accumulation in a HepG2 monoculture. In the coculture model, there was a non-significant trend (p = 0.08) towards higher (20–55% increased) median fat accumulation with maltose, kojibiose and nigerose. In this coculture model, cellular energy production was increased by glucose, maltose, kojibiose and nigerose, but not by trehalose. Furthermore, glucose, fructose and l-arabinose affected gene expression in a sugar-specific way in coculture HepG2 cells. These findings indicate that sugars provide structure-specific effects on cellular energy production, hepatic fat accumulation and gene expression, suggesting a health potential for trehalose and l-arabinose, as well as a differential impact of sugars beyond the distinction of conventional and rare sugars.

Trends in Antidiabetic Drug Discovery: FDA Approved Drugs, New Drugs in Clinical Trials and Global Sales

Type 2 diabetes mellitus (T2DM) continues to be a substantial medical problem due to its increasing global prevalence and because chronic hyperglycemic states are closely linked with obesity, liver disease and several cardiovascular diseases. Since the early discovery of insulin, numerous antihyperglycemic drug therapies to treat diabetes have been approved, and also discontinued, by the United States Food and Drug Administration (FDA). To provide an up-to-date account of the current trends of antidiabetic pharmaceuticals, this review offers a comprehensive analysis of the main classes of antihyperglycemic compounds and their mechanisms: insulin types, biguanides, sulfonylureas, meglitinides (glinides), alpha-glucosidase inhibitors (AGIs), thiazolidinediones (TZD), incretin-dependent therapies, sodium-glucose cotransporter type 2 (SGLT2) inhibitors and combinations thereof. The number of therapeutic alternatives to treat T2DM are increasing and now there are nearly 60 drugs approved by the FDA. Beyond this there are nearly 100 additional antidiabetic agents being evaluated in clinical trials. In addition to the standard treatments of insulin therapy and metformin, there are new drug combinations, e.g., containing metformin, SGLT2 inhibitors and dipeptidyl peptidase-4 (DPP4) inhibitors, that have gained substantial use during the last decade. Furthermore, there are several interesting alternatives, such as lobeglitazone, efpeglenatide and tirzepatide, in ongoing clinical trials. Modern drugs, such as glucagon-like peptide-1 (GLP-1) receptor agonists, DPP4 inhibitors and SGLT2 inhibitors have gained popularity on the pharmaceutical market, while less expensive over the counter alternatives are increasing in developing economies. The large heterogeneity of T2DM is also creating a push towards more personalized and accessible treatments. We describe several interesting alternatives in ongoing clinical trials, which may help to achieve this in the near future.

NEFAs Influence the Inflammatory and Insulin Signaling Pathways Through TLR4 in Primary Calf Hepatocytes in vitro

Transition dairy cows are often in a state of negative energy balance because of decreased dry matter intake and increased energy requirements, initiating lipid mobilization and leading to high serum β-hydroxybutyrate (BHBA) and non-esterified fatty acid (NEFAs) levels, which can induce ketosis and fatty liver in dairy cows. Inflammation and insulin resistance are also common diseases in the perinatal period of dairy cows. What is the relationship between negative energy balance, insulin resistance and inflammation in dairy cows? To study the role of non-esterified fatty acids in the nuclear factor kappa beta (NF-κB) inflammatory and insulin signaling pathways through Toll-like receptor 4 (TLR4), we cultured primary calf hepatocytes and added different concentrations of NEFAs to assess the mRNA and protein levels of inflammatory and insulin signaling pathways. Our experiments indicated that NEFAs could activate the NF-κB inflammatory signaling pathway and influence insulin resistance through TLR4. However, an inhibitor of TLR4 alleviated the inhibitory effects of NEFAs on the insulin pathway. In conclusion, all of these results indicate that high-dose NEFAs (2.4 mM) can activate the TLR4/NF-κB inflammatory signaling pathway and reduce the sensitivity of the insulin pathway through the TLR4/PI3K/AKT metabolic axis.

Inhibition of Non-Small Cell Lung Cancer Proliferation and Survival by Rosemary Extract Is Associated with Activation of ERK and AMPK

Non-small cell lung cancer (NSCLC) represents an aggressive form of lung cancer which often develops resistance to chemo- and radiotherapy emphasizing a need to identify novel treatment agents to combat it. Many plants contain compounds with anti-inflammatory, antimicrobial, antidiabetic, and anticancer properties and some plant-derived chemicals are used in the treatment of cancer. A limited number of in vitro and in vivo animal studies provide evidence of anticancer effects of rosemary (Rosmarinus officinalis) extract (RE); however, no studies have explored its role in H1299 NSCLC cells, and its underlying mechanism(s) of action are not understood. The current study examined the effects of RE on H1299 cell proliferation, survival, and migration using specific assays. Additionally, immunoblotting was used to investigate the effects of RE treatment on signalling molecules implicated in cell growth and survival. Treatment with RE dose-dependently inhibited H1299 proliferation with an IC₅₀ value of 19 µg/mL. Similarly, RE dose-dependently reduced cell survival, and this reduction correlated with increased levels of cleaved poly (ADP-ribose) polymerase (PARP), a marker of apoptosis. RE was also able to inhibit cell migration as assessed with a wound healing assay. These cellular effects of RE were associated with an increase in phosphorylated levels of extracellular signal-regulated kinase (ERK), AMP-activated protein kinase (AMPK), and its downstream targets ACC, the mTORC1 protein raptor, and decreased p70S6K phosphorylation. More studies are required to fully examine the effects of RE against NSCLC.

Effects of Metformin in Heart Failure: From Pathophysiological Rationale to Clinical Evidence

Type 2 diabetes mellitus (T2DM) is a worldwide major health burden and heart failure (HF) is the most common cardiovascular (CV) complication in affected patients. Therefore, identifying the best pharmacological approach for glycemic control, which is also useful to prevent and ameliorate the prognosis of HF, represents a crucial issue. Currently, the choice is between the new drugs sodium/glucose co-transporter 2 inhibitors that have consistently shown in large CV outcome trials (CVOTs) to reduce the risk of HF-related outcomes in T2DM, and metformin, an old medicament that might end up relegated to the background while exerting interesting protective effects on multiple organs among which include heart failure. When compared with other antihyperglycemic medications, metformin has been demonstrated to be safe and to lower morbidity and mortality for HF, even if these results are difficult to interpret as they emerged mainly from observational studies. Meta-analyses of randomized controlled clinical trials have not produced positive results on the risk or clinical course of HF and sadly, large CV outcome trials are lacking. The point of force of metformin with respect to new diabetic drugs is the amount of data from experimental investigations that, for more than twenty years, still continues to provide mechanistic explanations of the several favorable actions in heart failure such as, the improvement of the myocardial energy metabolic status by modulation of glucose and lipid metabolism, the attenuation of oxidative stress and inflammation, and the inhibition of myocardial cell apoptosis, leading to reduced cardiac remodeling and preserved left ventricular function. In the hope that specific large-scale trials will be carried out to definitively establish the metformin benefit in terms of HF failure outcomes, we reviewed the literature in this field, summarizing the available evidence from experimental and clinical studies reporting on effects in heart metabolism, function, and structure, and the prominent pathophysiological mechanisms involved.

WSF-CT-11, a Sesquiterpene Derivative, Activates AMP-Activated Protein Kinase with Anti-diabetic Effects in 3T3-L1 Adipocytes

BACKGROUND

AMP-activated protein kinase (AMPK) is a therapeutic target against type II diabetes (T2D). Synthetic sesquiterpene derivatives were investigated to identify novel AMPK activators as anti-diabetic drugs because the leading drugs like metformin and thiazolidinediones (TZDs) activate AMPK by inhibiting the synthesis of adenosine 5'-triphosphate and thus are associated with some side effects.

RESULTS

We identified WSF-CT-11 as an AMPK activator in HEK293T cells and found that WSF-CT-11 activates AMPK by the activation of transient receptor potential vanilloid type 1 (TRPV1), a Ca²⁺-permeable cation channel. The increased Ca²⁺ influx then activates phosphoinositide 3-kinase (PI3K), protein kinase B (PKB/Akt), and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII), which in turn phosphorylates TRPV1 and facilitates the formation of a TRPV1/Akt/CaMKII/AMPK complex. This complex might be important for the regulation of AMPK activity. In 3T3-L1 adipocytes, WSF-CT-11-induced AMPK activation has three anti-diabetic effects. It promotes the assembly of high-molecular-weight adiponectin, which has stronger insulin-sensitizing activity than other multimers. It improves translocation of the glucose transporter type 4, increases glucose uptake, and induces the inhibitory phosphorylation of peroxisome proliferator-activated receptor γ and thus suppresses adipogenesis.

CONCLUSION

WSF-CT-11 is a novel AMPK activator and potential drug against T2D without the side effects of metformin and TZDs.

Adverse Effects of Metformin From Diabetes to COVID-19, Cancer, Neurodegenerative Diseases, and Aging: Is VDAC1 a Common Target?

Metformin has been used for treating diabetes mellitus since the late 1950s. In addition to its antihyperglycemic activity, it was shown to be a potential drug candidate for treating a range of other diseases that include various cancers, cardiovascular diseases, diabetic kidney disease, neurodegenerative diseases, renal diseases, obesity, inflammation, COVID-19 in diabetic patients, and aging. In this review, we focus on the important aspects of mitochondrial dysfunction in energy metabolism and cell death with their gatekeeper VDAC1 (voltage-dependent anion channel 1) as a possible metformin target, and summarize metformin's effects in several diseases and gut microbiota. We question how the same drug can act on diseases with opposite characteristics, such as increasing apoptotic cell death in cancer, while inhibiting it in neurodegenerative diseases. Interestingly, metformin's adverse effects in many diseases all show VDAC1 involvement, suggesting that it is a common factor in metformin-affecting diseases. The findings that metformin has an opposite effect on various diseases are consistent with the fact that VDAC1 controls cell life and death, supporting the idea that it is a target for metformin.

Neurobiological Opportunities in Diabetic Polyneuropathy

This review highlights a selection of potential translational directions for the treatment of diabetic polyneuropathy (DPN) currently irreversible and without approved interventions beyond pain management. The list does not include all diabetic targets that have been generated over several decades of research but focuses on newer work. The emphasis is firstly on approaches that support the viability and growth of peripheral neurons and their ability to withstand a barrage of diabetic alterations. We include a section describing Schwann cell targets and finally how mitochondrial damage has been a common element in discussing neuropathic damage. Most of the molecules and pathways described here have not yet reached clinical trials, but many trials have been negative to date. Nonetheless, these failures clear the pathway for new thoughts over reversing DPN.

Increased oxidative stress contributes to enhance brain amyloidogenesis and blunts energy metabolism in sucrose-fed rat: effect of AMPK activation

Metabolic disturbances are linked to neurodegenerative diseases such as Alzheimer disease (AD). However, the cellular mechanisms underlying this connection are unclear. We evaluated the role of oxidative stress (OS), during early metabolic syndrome (MetS), on amyloidogenic processes in a MetS rat model induced by sucrose. MetS caused OS damage as indicated by serum and hypothalamus lipid peroxidation and elevated serum catalase activity. Tissue catalase and superoxide dismutase activity were unchanged by MetS, but gene expression of nuclear factor erythroid-derived 2-like 2 (NFE2L2), which up-regulates expression of antioxidant enzymes, was higher. Expression of amyloid-β cleaving enzyme 1 (BACE-1) and amyloid precursor protein (APP), key proteins in the amyloidogenesis pathway, were slightly increased by sucrose-intake in the hippocampus and hypothalamus. Activation and expression of protein kinase B (PKB) and AMP-dependent protein kinase (AMPK), pivotal proteins in metabolism and energy signaling, were similarly affected in the hippocampus and hypothalamus of MetS rats. Brain creatine kinase activity decreased in brain tissues from rats with MetS, mainly due to irreversible oxidation. Chronic metformin administration partially reversed oxidative damage in sucrose-fed animals, together with increased AMPK activation; probably by modulating BACE-1 and NFE2L2. AMPK activation may be considered as a preventive therapy for early MetS and associated neurodegenerative diseases.

Therapeutics for type-2 diabetes mellitus: a glance at the recent inclusions and novel agents under development for use in clinical practice

Diabetes mellitus (DM) is a chronic, progressive, and multifaceted illness resulting in significant physical and psychological detriment to patients. As of 2019, 463 million people are estimated to be living with DM worldwide, out of which 90% have type-2 diabetes mellitus (T2DM). Over the years, significant progress has been made in identifying the risk factors for developing T2DM, understanding its pathophysiology and uncovering various metabolic pathways implicated in the disease process. This has culminated in the implementation of robust prevention programmes and the development of effective pharmacological agents, which have had a favourable impact on the management of T2DM in recent times. Despite these advances, the incidence and prevalence of T2DM continue to rise. Continuing research in improving efficacy, potency, delivery and reducing the adverse effect profile of currently available formulations is required to keep pace with this growing health challenge. Moreover, new metabolic pathways need to be targeted to produce novel pharmacotherapy to restore glucose homeostasis and address metabolic sequelae in patients with T2DM. We searched PubMed, MEDLINE, and Google Scholar databases for recently included agents and novel medication under development for treatment of T2DM. We discuss the pathophysiology of T2DM and review how the emerging anti-diabetic agents target the metabolic pathways involved. We also look at some of the limiting factors to developing new medication and the introduction of unique methods, including facilitating drug delivery to bypass some of these obstacles. However, despite the advances in the therapeutic options for the treatment of T2DM in recent years, the industry still lacks a curative agent.