Oxidative stress and diabetic vascular complications

Unlocking the power of empagliflozin: Rescuing inflammation in hyperglycaemia-exposed human cardiomyocytes through comprehensive multi-level analysis

AIMS

Hyperglycaemic conditions increase cardiac stress, a common phenomenon associated with inflammation, aging, and metabolic imbalance. Sodium-glucose cotransporter 2 inhibitors, a class of anti-diabetic drugs, showed to improve cardiovascular functions although their mechanism of action has not yet been fully established. This study investigated the effects of empagliflozin on cardiomyocytes following high glucose exposure, specifically focusing on inflammatory and metabolic responses.

METHODS AND RESULTS

A three-part strategy was formulated: (i) a meta-analysis of selected randomized clinical trials was carried out to assess the anti-inflammatory effects of empagliflozin in diabetic patients; (ii) the impact of empagliflozin on human cardiomyocyte AC16 cells exposed to normal (5 mM) and high (33 mM) glucose concentrations for 2 and 7 days was explored by evaluating gene expression and protein levels of pivotal markers associated with cardiac inflammation, stress, endoplasmic reticulum damage, and calcium modulation; (iii) in silico data from bioinformatic analyses were exploited to construct an interaction map delineating the potential mechanism of action of empagliflozin on cardiac tissue. Empagliflozin reversed high-glucose mediated alterations at the transcriptional level, decreasing inflammatory, metabolic, and aging signatures. Specifically, in vitro experiments on human cardiomyocytes, meta-analyses of clinical data on inflammatory biomarkers from diabetic peripheral blood samples, and sequencing of pathological human heart tissues, all support that empagliflozin exerts anti-inflammatory effects both systemically and directly in cardiac tissue, on cardiomyocytes.

CONCLUSION

Our study provides insights based on robust mechanistic data for optimizing heart failure management and highlights the intricate interplay between diabetes, inflammation, aging, and cardiovascular health.

Molecular mechanisms and therapeutic perspectives of luteolin on diabetes and its complications

BACKGROUND

Extensive preclinical studies have established luteolin, a flavonoid with potent antidiabetic activity, as a therapeutic candidate for preventing and managing various diabetic complications including cardiomyopathy, nephropathy, and osteopathy. This systematic review evaluates current evidence regarding luteolin's antidiabetic potential.

AIM OF THE STUDY

This study evaluates luteolin's efficacy in diabetes management through evidence synthesis, while critically assessing current research challenges and translational opportunities.

METHODS

A comprehensive literature search was conducted across Pubmed, Embase, Web of Science, and Google Scholar databases, encompassing articles published between 2000 and 2024.

RESULTS

Luteolin is a naturally occurring flavonoid that has strong antidiabetic properties. It regulates intestinal microenvironmental homeostasis, lipogenesis and catabolism, and the absorption of carbohydrates. It also modulates nine diabetic complications by reducing inflammation, oxidative stress, apoptosis, and autophagy. Luteolin's potential nutritional and physiological benefits notwithstanding, attention must be directed immediately to its bioavailability, innovative formulations, safety assessment, synergistic effects, and optimal dosage and time for supplementation. In particular, clinical studies are needed to validate efficacy and safety and provide a reliable scientific basis.

CONCLUSION

Luteolin may act as a pleiotropic molecule targeting multiple signaling cascades to exert antidiabetic bioactivity.

Effects of switching from dipeptidyl peptidase 4 inhibitors to oral semaglutide on oxidative stress and glycemic variability in patients with type 2 diabetes: an open-label, prospective, randomized, multicenter, parallel-group comparison study

BACKGROUND

To compare the effects of switching from dipeptidyl peptidase 4 (DPP-4) inhibitors to oral semaglutide on oxidative stress and glucose variability assessed by continuous glucose monitoring in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was an open-label, prospective, randomized, multicenter, parallel-group comparison study conducted over 24 weeks. Patients with T2DM who had been taking regular doses of DPP-4 inhibitors for at least 12 weeks were enrolled. They were randomly assigned to either continue on DPP-4 inhibitors (DPP-4 inhibitor group) or switch to oral semaglutide at 3 mg/day, with a dose increase to 7 mg/day after 4 weeks (semaglutide group). The primary endpoint was the change in the diacron-reactive oxygen metabolites test, an oxidative stress marker. Secondary endpoints included changes in glucose variability assessed using continuous glucose monitoring, metabolic indices, physical assessments, and Diabetes Treatment Satisfaction Questionnaire scores.

RESULTS

Fifty-eight patients with T2DM were randomized to the semaglutide group (n = 30) and the DPP-4 inhibitor group (n = 28). Six patients in the semaglutide group and one patient in the DPP-4 inhibitor group dropped out during the study. Ultimately, data from 24 patients in the semaglutide group and 27 patients in the DPP-4 inhibitor group were included for analysis. Switching to oral semaglutide therapy for 24 weeks significantly reduced oxidative stress, glucose variability, and hemoglobin A1c levels compared to continuous treatment with DPP-4 inhibitors. However, there was no significant difference in Diabetes Treatment Satisfaction Questionnaire scores between the two groups.

(II) CONCLUSIONS

Our study demonstrated that switching to oral semaglutide therapy from DPP-4 inhibitors significantly improved oxidative stress and glycemic parameters, including glucose variability, in patients with T2DM.

TRIAL REGISTRATION

jRCT1031210620.

Nonprescription Magnesium Supplement Use and Risk of Heart Failure in Patients With Diabetes: A Target Trial Emulation

BACKGROUND

Both diabetes and low magnesium-containing food intake may increase the risk of heart failure (HF). However, the effect of nonprescription magnesium supplements on the risk of HF or major adverse cardiac events in patients with diabetes is unknown.

METHODS AND RESULTS

Using a target-trial-emulation approach, we assembled a national cohort of 94 239 veterans ≥40 years with diabetes, without prior HF or magnesium use, who received ambulatory care in the US veterans-health care system documented by electronic clinic notes between January 1, 2006 and December 31, 2020. A natural language processing approach was used to detect self-reported magnesium-supplement use from clinic notes, n=17 619 were identified as users versus n=76 620 as nonusers. Using inverse probability treatment weighting, we constructed a cohort balanced in 88 baseline characteristics between users and nonusers. The primary outcome was incident HF. Secondary outcomes were major adverse cardiac events (myocardial infarction, stroke, HF hospitalization, or death). Hazard ratios (HRs) associated with magnesium-supplement use and outcomes were estimated in the inverse probability treatment weighting weighted cohort using Cox regression. The inverse probability treatment weighting weighted cohort had a mean age of 67.4±10.3 years; 18.4% were Black, and 5.1% were women. The mean duration of magnesium-supplement use was 3.5±3.1 (interquartile range, 1.1-5.1) years. Incident HF occurred in 8.0% of users and 9.7% of nonusers of magnesium supplements (HR, 0.94 [95% CI, 0.89-0.99]). Magnesium-supplement use was also associated with a reduced risk of major adverse cardiac events (HR, 0.94 [95% CI, 0.90-0.97]).

CONCLUSIONS

Long-term nonprescription magnesium supplement use was associated with a lower risk of incident HF and major adverse cardiac events in patients with diabetes. These findings should be replicated in randomized controlled trials.

Transcriptomics and microbiome insights reveal the protective mechanism of mulberry-derived postbiotics against inflammation in LPS-induced mice

Background

Natural food-derived bioactive compounds have garnered increasing attention for their potential to modulate immune responses and promote gut health. In particular, compounds like mulberry-derived postbiotics (MDP) may offer novel therapeutic strategies to address inflammation, a key driver of many metabolic disorders.

Methodology

This study examines the protective effects of MDP against inflammation in LPS-induced mice, using transcriptomic and microbiome analyses to explore underlying mechanisms.

Results

MDP pretreatment alleviates LPSinduced villous atrophy and intestinal barrier damage, promoting recovery of intestinal morphology. Transcriptomic profiling revealed significant changes in gene expression, with 983 upregulated and 1220 downregulated genes in the NC vs LPS comparison, and 380 upregulated and 204 downregulated genes in the LPS vs LPS+MDP comparison. Enrichment analysis using GO and KEGG pathways revealed significant associations with transcriptional regulatory activity, and the NOD-like receptor signaling pathway among the differentially expressed genes. Protein-protein interaction analysis identified key genes involved in inflammation and immune regulation, with hub genes like IL6, CXCL10, and MYD88 in the LPS group and CD74, CIITA, and H2-AB1 in the MDP-treated group.

Conclusion

Microbiome analysis suggested MDP may also influence gut microbiota composition, supporting systemic immune regulation. These findings highlight MDP's potential as a food additive for immune modulation and gut health.

Physiological mechanisms of neuromuscular impairment in diabetes-related complications: Can physical exercise help prevent it?

Diabetes mellitus is a chronic disorder that progressively induces complications, compromising daily independence. Among these, diabetic neuropathy is particularly prevalent and contributes to substantial neuromuscular impairments in both types 1 and 2 diabetes. This condition leads to structural damage affecting both the central and peripheral nervous systems, resulting in a significant decline in sensorimotor functions. Alongside neuropathy, diabetic myopathy also contributes to muscle impairment and reduced motor performance, intensifying the neuromuscular decline. Diabetic neuropathy typically implicates neurogenic muscle atrophy, motoneuron loss and clustering of muscle fibres as a result of aberrant denervation-reinervation processes. These complications are associated with compromised neuromuscular junctions, where alterations occur in pre-synaptic vesicles, mitochondrial content and post-synaptic signalling. Neural damage is intensified by chronic hyperglycaemia and oxidative stress, exacerbating vascular dysfunction and reducing oxygen delivery. These complications imply a severe decline in neuromuscular performance, evidenced by reductions in maximal force and power output, rate of force development and muscle endurance. Furthermore, diabetes-related complications are compounded by age-related degenerative changes in long-term patients. Aerobic and resistance training offer promising approaches for managing blood glucose levels and neuromuscular function. Aerobic exercise promotes mitochondrial biogenesis and angiogenesis, supporting metabolic and cardiovascular health. Resistance training primarily enhances neural plasticity, muscle strength and hypertrophy, which are crucial factors for mitigating sarcopenia and preserving functional independence. This topical review examines current evidence on the physiological mechanisms underlying diabetic neuropathy and the potential impact of physical activity in counteracting this decline.

O-linked β-N-acetylglucosamine (O-GlcNAc) modification: Emerging pathogenesis and a therapeutic target of diabetic nephropathy

AIMS

O-Linked β-N-acetylglucosamine (O-GlcNAc) modification, a unique post-translational modification of proteins, is elevated in diabetic nephropathy. This review aims to summarize the current knowledge on the mechanisms by which O-GlcNAcylation of proteins contributes to the pathogenesis and progression of diabetic nephropathy, as well as the therapeutic potential of targeting O-GlcNAc modification for its treatment.

METHODS

Current evidence in the literature was reviewed and synthesized in a narrative review.

RESULTS

Hyperglycemia increases glucose flux into the hexosamine biosynthesis pathway, which activates glucosamino-fructose aminotransferase expression and activity, leading to the production of O-GlcNAcylation substrate UDP-GlcNAc and an increase in protein O-GlcNAcylation in kidney cells. Protein O-GlcNAcylation regulates the function of kidney cells including mesangial cells, podocytes, and proximal tubular cells, and promotes renal interstitial fibrosis, resulting in kidney damage. Current treatments for diabetic nephropathy, such as sodium-glucose cotransporter 2 (SGLT-2) inhibitors and renin-angiotensin-aldosterone system (RAAS) inhibitors, delay disease progression, and suppress protein O-GlcNAcylation.

CONCLUSIONS

Increased protein O-GlcNAcylation mediates renal cell damage and promotes renal interstitial fibrosis, leading to diabetic nephropathy. Although the full significance of inhibition of O-GlcNAcylation is not yet understood, it may represent a novel target for treating diabetic nephropathy.

TiOx(OH)4-2x Nanosheets with Catalytic Antioxidative Activity Alleviate Oxidative Injury in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is one of the most lethal complications of diabetes and is induced by the overproduction of reactive oxygen species (ROS) in cardiomyocytes due to sustained high glucose levels, leading to cardiac oxidative damage and final sudden death. Drugs and antioxidants currently applied to the clinical therapy of DCM fail to scavenge ROS efficiently, resulting in compromised therapeutic efficacy. Herein, a nanocatalytic antioxidative therapeutic strategy is proposed for DCM treatment. A two-dimensional TiOx(OH)4-2x nanosheet platform has been constructed with efficient ROS-scavenging activity, which can catalyze antioxidation reaction through redox cycling between TiIV/TiIII accompanied by inner-sphere two-electron transfer. Cellular experiments demonstrate that the TiOx(OH)4-2x nanosheet can not only protect cardiomyocytes from oxidative damage induced by a high glucose environment but also alleviate inflammation to further protect cardiomyocytes from inflammatory injury. The in vivo animal model confirms that the nanosheet alleviates myocardial oxidative injury and recovers cardiac function. Such a nanocatalytic antioxidation strategy is expected to provide a feasible approach for treating DCM and other cardiovascular diseases.

Cromolyn sodium and masitinib combination inhibits fibroblast-myofibroblast transition and exerts additive cell-protective and antioxidant effects on a bleomycin-induced in vitro fibrosis model

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal fibrotic lung disease. While recent studies have suggested the potential efficacy of tyrosine kinase inhibitors in managing IPF, masitinib, a clinically used tyrosine kinase inhibitor, has not yet been investigated for its efficacy in fibrotic lung diseases. In a previous study on an in vitro neurodegenerative model, we demonstrated the synergistic antitoxic and antioxidant effects of masitinib combined with cromolyn sodium, an FDA-approved mast cell stabilizer. This study aims to investigate the anti-fibrotic and antioxidant effects of the masitinib-cromolyn sodium combination in an in vitro model of pulmonary fibrosis. Fibroblast cell cultures treated with bleomycin and/or hydrogen peroxide (H2O2) were subjected to masitinib and/or cromolyn sodium, followed by assessments of cell viability, morphological and apoptotic nuclear changes, triple-immunofluorescence labeling, and total oxidant/antioxidant capacities, besides ratio of Bax and Bcl-2 mRNA expressions as an indication of apoptosis. The combined treatment of masitinib and cromolyn sodium effectively prevented the fibroblast myofibroblast transition, a hallmark of fibrosis, and significantly reduced bleomycin / H2O2-induced apoptosis and oxidative stress. This study is the first to demonstrate the additive anti-fibrotic, cell-protective, and antioxidant effects of the masitinib-cromolyn sodium combination in an in vitro fibrosis model, suggesting its potential as an innovative therapeutic approach for pulmonary fibrosis. Combination therapy may be more advantageous in that both drugs could be administered in lower doses, exerting less side effects, and at the same time providing diverse mechanisms of action simultaneously.

Manipulation of Post-Prandial Hyperglycaemia in Type 2 Diabetes: An Update for Practitioners

This review paper explores post-prandial glycemia in type 2 diabetes. Post-prandial glycemia is defined as the period of blood glucose excursion from immediately after the ingestion of food or drink to 4 to 6 hours after the end of the meal. Post-prandial hyperglycemia is an independent risk factor for cardiovascular disease with glucose "excursions" being more strongly associated with markers of oxidative stress than the fasting or pre-prandial glucose level. High blood glucose is a major promoter of enhanced free radical production and is associated with the onset and progression of type 2 diabetes. Oxidative stress impairs insulin action creating a vicious cycle where repeated post-prandial glucose spikes are key drivers in the pathogenesis of the vascular complications of type 2 diabetes, both microvascular and macrovascular. Some authors suggest post-prandial hyperglycemia is the major cause of death in type 2 diabetes. Proper management of post-prandial hyperglycemia could yield up to a 35% cut in overall cardiovascular events, and a 64% cut in myocardial infarction. The benefits of managing post-prandial hyperglycemia are similar in magnitude to those seen in type 2 diabetes patients receiving secondary prevention with statins - prevention which today is regarded as fundamental by all practitioners. Given all the evidence surrounding the impact of post-prandial glycemia on overall outcome, it is imperative that any considered strategy for the management of type 2 diabetes should include optimum dietary, pharma, and lifestyle interventions that address glucose excursion. Achieving a low post-prandial glucose response is key to prevention and progression of type 2 diabetes and cardiometabolic diseases. Further, such therapeutic interventions should be sustainable and must benefit patients in the short and long term with the minimum of intrusion and side effects. This paper reviews the current literature around dietary manipulation of post-prandial hyperglycemia, including novel approaches. A great deal of further work is required to optimize and standardize the dietary management of post-prandial glycemia in type 2 diabetes, including consideration of novel approaches that show great promise.

Oxidative and Nitrous Stress Underlies Vascular Malfunction Induced by Ionizing Radiation and Diabetes

Oxidative stress results from the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in quantities exceeding the potential activity of the body's antioxidant system and is one of the risk factors for the development of vascular dysfunction in diabetes and exposure to ionizing radiation. Being the secondary products of normal aerobic metabolism in living organisms, ROS and RNS act as signaling molecules that play an important role in the regulation of vital organism functions. Meanwhile, in high concentrations, these compounds are toxic and disrupt various metabolic pathways. The various stress factors (hyperglycemia, gamma-irradiation, etc.) trigger free oxygen and nitrogen radicals accumulation in cells that are capable to damage almost all cellular components including ion channels and transporters such as Na+/K+-ATPase, BKCa, and TRP channels. Vascular dysfunctions are governed by interaction of ROS and RNS. For example, the reaction of ROS with NO produces peroxynitrite (ONOO-), which not only oxidizes DNA, cellular proteins, and lipids, but also disrupts important signaling pathways that regulate the cation channel functions in the vascular endothelium. Further increasing in ROS levels and formation of ONOO- leads to reduced NO bioavailability and causes endothelial dysfunction. Thus, imbalance of ROS and RNS and their affect on membrane ion channels plays an important role in the pathogenesis of vascular dysfunction associated with various disorders.

Cereblon deficiency ameliorates carbon tetrachloride-induced acute hepatotoxicity in HepG2 cells by suppressing MAPK-mediated apoptosis

The liver is vulnerable to various hepatotoxins, including carbon tetrachloride (CCl4), which induces oxidative stress and apoptosis by producing reactive oxygen species (ROS) and activating the mitogen-activated protein kinase (MAPK) pathway. Cereblon (CRBN), a multifunctional protein implicated in various cellular processes, functions in the pathogenesis of various diseases; however, its function in liver injury remains unknown. We established a CRBN-knockout (KO) HepG2 cell line and examined its effect on CCl4-induced hepatocellular damage. CRBN-KO cells exhibited reduced sensitivity to CCl4-induced cytotoxicity, as evidenced by decreased levels of apoptosis markers, such as cleaved caspase-3, and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. CRBN deficiency enhanced antioxidant defense, with increased superoxide dismutase activity and glutathione ratios (GSH/GSSG), as well as reduced pro-inflammatory cytokine expression. Mechanistically, the protective effects of CRBN deficiency appeared to involve the attenuation of the MAPK-mediated pathways, particularly through decreased phosphorylation of JNK and ERK. Overall, these results suggest the crucial role of CRBN in mediating the hepatocellular response to oxidative stress and inflammation triggered by CCl4 exposure, offering potential clinical implications for liver injury in a wide range of liver diseases.

Hypoglycemic Ability of Sericin-Derived Oligopeptides (SDOs) from Bombyx mori Yellow Silk Cocoons and Their Physiological Effects on Streptozotocin (STZ)-Induced Diabetic Rats

Patients with diabetes require daily medication to maintain blood sugar levels. Nevertheless, the long-term use of antidiabetics can lose efficacy and cause degeneration in some patients. For long-term diabetes care, integrating natural dietary foods and medicine is being considered. This study investigated the impact of SDOs on blood sugar levels and their physiological effects on diabetic rats. We induced diabetes in male Wistar rats with STZ (50 mg/kg) and then administered an oral glucose tolerance test to determine the SDO dosage comparable to glibenclamide. The rats were divided into nine groups: normal, diabetic, and diabetic with insulin (10 U/kg), glibenclamide (0.6 mg/kg), bovine serum albumin (BSA; 200 mg/kg), soy protein isolate (200 mg/kg), or SDOs (50, 100, and 200 mg/kg). Diabetic rats administered SDOs had a higher body weight and serum insulin but a lower blood sugar than diabetic control rats. Biochemical assays indicated lower AST/SGOT, ALT/SGPT, BUN, and triglycerides but higher HDL in the SDO groups. Immunohistochemistry showed that SDOs reduced damaged islet cells, increased beta-cell size, and improved insulin levels while decreasing alpha cell size and glucagon. The vascular effects of SDOs were like those of normal control treatment and insulin treatment in diabetic rats. SDOs, a yellow silk protein, show potential for long-term diabetes care.

Lonicerin promotes wound healing in diabetic rats by enhancing blood vessel regeneration through Sirt1-mediated autophagy

Among the numerous complications of diabetes mellitus, diabetic wounds seriously affect patients' quality of life and result in considerable psychological distress. Promoting blood vessel regeneration in wounds is a crucial step in wound healing. Lonicerin (LCR), a bioactive compound found in plants of the Lonicera japonica species and other honeysuckle plants, exhibits anti-inflammatory and antioxidant activities, and it recently has been found to alleviate ulcerative colitis by enhancing autophagy. In this study we investigated the efficacy of LCR in treatment of diabetic wounds and the underlying mechanisms. By comparing the single-cell transcriptomic data from healing and non-healing states in diabetic foot ulcers (DFU) of 5 patients, we found that autophagy and SIRT signaling activation played a crucial role in mitigating inflammation and oxidative stress, and promoting cell survival in wound healing processes. In TBHP-treated human umbilical vein endothelial cells (HUVECs), we showed that LCR alleviated cell apoptosis, and enhanced the cell viability, migration and angiogenesis. Furthermore, we demonstrated that LCR treatment dose-dependently promoted autophagy in TBHP-treated HUVECs by upregulating Sirt1 expression, and exerted its anti-apoptotic effect through the Sirt1-autophagy axis. Knockdown of Sirt1 significantly decreased the level of autophagy, and mitigated the anti-apoptotic effect of LCR. In a STZ-induced diabetic rat model, administration of LCR significantly promoted wound healing, which was significantly attenuated by Sirt1 knockdown. This study highlights the potential of LCR as a therapeutic agent for the treatment of diabetic wounds and provides insights into the molecular mechanisms underlying its effects.

A Narrative Review of Diabetic Macroangiopathy: From Molecular Mechanism to Therapeutic Approaches

Diabetic macroangiopathy, a prevalent and severe complication of diabetes mellitus, significantly contributes to the increased morbidity and mortality rates among affected individuals. This complex disorder involves multifaceted molecular mechanisms that lead to the dysfunction and damage of large blood vessels, including atherosclerosis (AS) and peripheral arterial disease. Understanding the intricate pathways underlying the development and progression of diabetic macroangiopathy is crucial for the development of effective therapeutic interventions. This review aims to shed light on the molecular mechanism implicated in the pathogenesis of diabetic macroangiopathy. We delve into the intricate interplay of chronic inflammation, oxidative stress, endothelial dysfunction, and dysregulated angiogenesis, all of which contribute to the vascular complications observed in this disorder. By exploring the molecular mechanism involved in the disease we provide insight into potential therapeutic targets and strategies. Moreover, we discuss the current therapeutic approaches used for treating diabetic macroangiopathy, including glycemic control, lipid-lowering agents, and vascular interventions.

Short-term glucose variability as a determinant of the healing rate of diabetic foot ulcer: A retrospective study

BACKGROUND

The aim of this study was to describe the clinical characteristics of people with diabetic foot ulcer (DFU) according to glucose variability (GV) and to investigate the relationship between GV and DFU outcome in a population with type 2 diabetes (T2D) and DFU.

METHODS

This is a retrospective study of 300 individuals aged 64.3 years (181 males) treated for DFU in a tertiary-care center with a regular follow-up for 6 months. Laboratory measurements and clinical assessments were collected at baseline. According to the coefficient of variation (CV) cut-off (≥36%), people were divided into two groups (low and high GV).

RESULTS

Compared with low GV group (n = 245), high GV group (n = 55) had significant longer duration of diabetes [low vs high GV, mean ± Standard Deviation (SD), 17.8 ± 11.8 vs 22.4 ± 10.8, P = 0.012], higher levels of glycated haemoglobin [median (IQR), 7.4 (6.6, 8.8) vs 8.2 (7.0, 9.6), P = 0.010] and urinary albumin excretion [25.2 (11.9, 77.0) vs 48.0 (23.2, 106.0), P = 0.031]. Moreover, 10 days self-monitoring of blood glucose-derived glycemic metrics were significantly different between groups. No differences among clinical features were found. The multiple logistic regression analysis identified CV and SD as negative predictors of healing.

CONCLUSIONS

In a population of people with T2D and DFU treated in a tertiary-care center, individuals with high GV had a 3-fold higher risk of healing failure, as compared with those with low GV. CV and SD were related to poor healing within 6 months follow-up.

Emerging and multifaceted potential contributions of polyphenols in the management of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is recognized as a serious public health concern with a considerable impact on human life, long-term health expenditures, and substantial health losses. In this context, the use of dietary polyphenols to prevent and manage T2DM is widely documented. These dietary compounds exert their beneficial effects through several actions, including the protection of pancreatic islet β-cell, the antioxidant capacities of these molecules, their effects on insulin secretion and actions, the regulation of intestinal microbiota, and their contribution to ameliorate diabetic complications, particularly those of vascular origin. In the present review, we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type 2 diabetes patients.

Ameliorating impact of coenzyme Q10 on the profile of adipokines, cardiomyopathy, and hematological markers correlated with the glucotoxicity sequelae in diabetic rats

BACKGROUND

In diabetes, high blood glucose induces glucotoxicity, resulting in the further damage of pancreatic beta-cells and then precipitating diabetic complications. This study was aimed to investigate the relationship between glucotoxicity with the level of adipokines, diabetic cardiomyopathy, and hematological markers. Moreover, the study examined the potential modulatory effect of coenzyme Q10 (CoQ10) on the aforementioned markers associated with the sequelae of diabetes mellitus.

MATERIAL AND METHODS

Twenty-four male rats were randomly assigned to receive an injection of STZ to induce diabetes (n = 16) or to remain uninduced (n = 8). The hyperglycemic status was induced in fasting rats by single intraperitoneal injection of STZ (45 mg /kg b.w.) dissolved in citrate buffer (pH 4.5). Three days after STZ injection, rats were divided into three groups; Normal control group (A), Diabetic control group (B), and CoQ10- treated diabetic group (C). The group (C) was fed with the basal diet supplemented with 5 g of CoQ10 per kilogram of diet for three weeks after the diabetes induction. After 21 days, the blood and serum samples were taken to conduct biochemical analyses. Blood glucose was determined by Blood Glucose Monitoring System. Adipokines or cytokines were evaluated by ELISA from a serum sample. Cardiac myopathy biomarkers were estimated by UP-Converting Phosphor Immunoassay Analyzer, and hematological parameters were measured by automatic hematology analyzer.

RESULTS

In hyperglycemic rats, the level of fasting blood glucose, and serum level of resistin, omentin, TNF-α, and cardiomyopathy biomarkers significantly increased (P < 0.05). The treatment with CoQ10 significantly decreased the profile of adipokines and cardiomyopathy markers (cardiac enzymes and LPPLA2) in diabetic rats and also reduced glucose levels (P < 0.05). Lymphocyte percentages significantly decreased while significant increases were observed in granulocytes and MID percentages in hyperglycemic rats.

CONCLUSION

Diabetic rats had higher serum levels of adipokines and cardiomyopathy markers. Among the hematological markers, GRA% and MID% increased while LYM% decreased. The profile of adipokines and cardiomyopathy markers improved when CoQ10 was supplemented. The study suggests that CoQ10 may have a beneficial effect on improving diabetic complications.

Comparison of Effects of Injectable Semaglutide and Dulaglutide on Oxidative Stress and Glucose Variability in Patients with Type 2 Diabetes Mellitus: A Prospective Preliminary Study

INTRODUCTION

Recent trials have shown that glucagon-like peptide-1 receptor agonists considerably reduce atherosclerotic cardiovascular disease in patients with type 2 diabetes mellitus (T2DM). Oxidative stress, a surrogate marker of cardiovascular risk, is associated with glucose variability. However, to the best of our knowledge, no studies have compared the effects of injectable semaglutide and dulaglutide therapies on oxidative stress and glucose variability assessed via continuous glucose monitoring (CGM). This study aimed to analyze and compare the effects of semaglutide and dulaglutide therapies on oxidative stress and glucose variability as assessed through CGM.

METHODS

This is an open-label, multicenter, randomized, prospective, parallel-group comparison study. Overall, 37 patients with T2DM treated with dulaglutide for at least 12 weeks were randomized into two groups: one receiving continuous dulaglutide therapy (n = 19) and one receiving injectable semaglutide therapy (n = 18) groups. The coprimary endpoints were changes in the results of the diacron-reactive oxygen metabolites test, an oxidative stress marker, and CGM-evaluated glucose variability after 24 weeks. The secondary endpoint was changes in the Diabetes Treatment Satisfaction Questionnaire (DTSQ) scores.

RESULTS

Switching to semaglutide therapy was better than continuous dulaglutide therapy in reducing oxidative stress, glucose variability, and glycated hemoglobin levels. Conversely, continuous dulaglutide therapy was better than semaglutide therapy in terms of DTSQ scores for "Convenience" and "Recommend."

CONCLUSION

Injectable semaglutide therapy may be more effective than dulaglutide therapy in ameliorating oxidative stress and regulating glucose metabolism, including glucose variability, in patients with T2DM, while dulaglutide therapy may be more effective in terms of treatment satisfaction.

CLINICAL TRIAL REGISTRATION

UMIN-CRT ID: UMIN000042670 (registered 7 December 2020).

Diabetic Retinopathy and Cardiovascular Disease: A Literature Review

Diabetic complications can be divided into macrovascular complications such as cardiovascular disease and cerebrovascular disease and microvascular complications such as diabetic retinopathy, diabetic nephropathy and diabetic neuropathy. Among them, cardiovascular disease (CVD) is an important cause of death in diabetic patients. Diabetes retinopathy (DR) is one of the main reasons for the increasing disability rate of diabetes. In recent years, some studies have found that because DR and CVD have a common pathophysiological basis, the occurrence of DR and CVD are inseparable, and to a certain extent, DR can predict the occurrence of CVD. With the development of technology, the fundus parameters of DR can be quantitatively analyzed as an independent risk factor of CVD. In addition, the cytokines related to DR can also be used for early screening of DR. Although many advances have been made in the treatment of CVD, its situation of prevention and treatment is still not optimistic. This review hopes to discuss the feasibility of DR in predicting CVD from the common pathophysiological mechanism of DR and CVD, the new progress of diagnostic techniques for DR, and the biomarkers for early screening of DR.

Influence of Reactive Oxygen Species on Wound Healing and Tissue Regeneration in Periodontal and Peri-Implant Tissues in Diabetic Patients

Diabetes mellitus (DM) is associated with periodontal disease. Clinically, periodontal treatment is less effective for patients with DM. Oxidative stress is one of the mechanisms that link DM to periodontitis. The production of reactive oxygen species (ROS) is increased in the periodontal tissues of patients with DM and is involved in the development of insulin resistance in periodontal tissues. Insulin resistance decreases Akt activation and inhibits cell proliferation and angiogenesis. This results in the deterioration of wound healing and tissue repair in periodontal tissues. Antioxidants and insulin resistance ameliorants may inhibit ROS production and improve wound healing, which is worsened by DM. This manuscript provides a comprehensive review of the most recent basic and clinical evidence regarding the generation of ROS in periodontal tissues resulting from microbial challenge and DM. This study also delves into the impact of oxidative stress on wound healing in the context of periodontal and dental implant therapies. Furthermore, it discusses the potential benefits of administering antioxidants and anti-insulin resistance medications, which have been shown to counteract ROS production and inflammation. This approach may potentially enhance wound healing, especially in cases exacerbated by hyperglycemic conditions.

Potential use of the Asteraceae family as a cure for diabetes: A review of ethnopharmacology to modern day drug and nutraceuticals developments

The diabetes-associated mortality rate is increasing annually, along with the severity of its accompanying disorders that impair human health. Worldwide, several medicinal plants are frequently urged for the management of diabetes. Reports are available on the use of medicinal plants by traditional healers for their blood-sugar-lowering effects, along with scientific evidence to support such claims. The Asteraceae family is one of the most diverse flowering plants, with about 1,690 genera and 32,000 species. Since ancient times, people have consumed various herbs of the Asteraceae family as food and employed them as medicine. Despite the wide variety of members within the family, most of them are rich in naturally occurring polysaccharides that possess potent prebiotic effects, which trigger their use as potential nutraceuticals. This review provides detailed information on the reported Asteraceae plants traditionally used as antidiabetic agents, with a major focus on the plants of this family that are known to exert antioxidant, hepatoprotective, vasodilation, and wound healing effects, which further action for the prevention of major diseases like cardiovascular disease (CVD), liver cirrhosis, and diabetes mellitus (DM). Moreover, this review highlights the potential of Asteraceae plants to counteract diabetic conditions when used as food and nutraceuticals. The information documented in this review article can serve as a pioneer for developing research initiatives directed at the exploration of Asteraceae and, at the forefront, the development of a botanical drug for the treatment of DM.

Long-Term Experimental Hyperglycemia Does Not Impair Macrovascular Endothelial Barrier Integrity and Function in vitro

Hyperglycemia is a hallmark of type 2 diabetes implicated in vascular endothelial dysfunction and cardiovascular complications. Many in vitro studies identified endothelial apoptosis as an early outcome of experimentally modeled hyperglycemia emphasizing cell demise as a significant factor of vascular injury. However, endothelial apoptosis has not been observed in vivo until the late stages of type 2 diabetes. Here, we studied the long-term (up to 4 weeks) effects of high glucose (HG, 30 mM) on human umbilical vein endothelial cells (HUVEC) in vitro. HG did not alter HUVEC monolayer morphology, ROS levels, NO production, and exerted minor effects on the HUVEC apoptosis markers. The barrier responses to various clues were indistinguishable from those by cells cultured in physiological glucose (5 mM). Tackling the key regulators of cytoskeletal contractility and endothelial barrier revealed no differences in the histamine-induced intracellular Ca2+ responses, nor in phosphorylation of myosin regulatory light chain or myosin light chain phosphatase. Altogether, these findings suggest that vascular endothelial cells may well tolerate HG for relatively long exposures and warrant further studies to explore mechanisms involved in vascular damage in advanced type 2 diabetes.

Promising remedies for cardiovascular disease: Natural polyphenol ellagic acid and its metabolite urolithins

BACKGROUND

Cardiovascular disease (CVD) is a significant worldwide factor contributing to human fatality and morbidity. With the increase of incidence rates, it is of concern that there is a lack of current therapeutic alternatives because of multiple side effects. Ellagic acid (EA), the natural polyphenol (C14H6O8), is abundant in pomegranates, berries, and nuts. EA and its intestinal microflora metabolite, urolithins, have recently attracted much attention as a potential novel "medicine" because of their wide pharmacological properties.

PURPOSE

This study aimed to critically analyze available literature to summarize the beneficial effects of EA and urolithins, and highlights their druggability and therapeutic potential in various CVDs.

METHODS

We systematically studied research and review articles between 1984 and 2022 available on various databases to obtain the data on EA and urolithins with no language restriction. Their cardiovascular protective activities, underlying mechanism, and druggability were highlighted and discussed comprehensively.

RESULTS

We found that EA and urolithins may exert preventive and curative effects on CVD with negligible side effects and possibly regulate lipid metabolism imbalance, pro-inflammatory factor production, vascular smooth muscle cell proliferation, cardiomyocyte apoptosis, endothelial cell dysfunction, and Ca2+ intake and release. Potentially, this may lead to the prevention and amelioration of atherosclerosis, hypertension, myocardial infarction, cardiac fibrosis, cardiomyopathy, cardiac arrhythmias, and cardiotoxicities in vivo. Several molecules and signaling pathways are associated with their therapeutic actions, including phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, NF-κB, nuclear factor erythroid-2 related factor 2, sirtuin1, miRNA, and extracellular signal-regulated kinase 1/2.

CONCLUSION

In vitro and in vivo studies shows that EA and urolithins could be used as valid candidates for early prevention and effective therapeutic strategies for various CVDs.

Vitamin C Urinary Loss in Fabry Disease: Clinical and Genomic Characteristics of Vitamin C Renal Leak

BACKGROUND

Reduced plasma vitamin C concentrations in chronic diseases may result from abnormal urinary excretion of vitamin C: a renal leak. We hypothesized that vitamin C renal leak may be associated with disease-mediated renal dysregulation, resulting in aberrant vitamin C renal reabsorption and increased urinary loss.

OBJECTIVES

We investigated the prevalence, clinical characteristics, and genomic associations of vitamin C renal leak in Fabry disease, an X-linked lysosomal disease associated with renal tubular dysfunction and low plasma vitamin C concentrations.

METHODS

We conducted a non-randomized cross-sectional cohort study of men aged 24-42 y, with Fabry disease (n = 34) and controls without acute or chronic disease (n = 33). To match anticipated plasma vitamin C concentrations, controls were placed on a low-vitamin C diet 3 wk before inpatient admission. To determine the primary outcome of vitamin C renal leak prevalence, subjects were fasted overnight, and matched urine and fasting plasma vitamin C measurements were obtained the following morning. Vitamin C renal leak was defined as presence of urinary vitamin C at plasma concentrations below 38 μM. Exploratory outcomes assessed the association between renal leak and clinical parameters, and genomic associations with renal leak using single nucleotide polymorphisms (SNPs) in the vitamin C transporter SLC23A1.

RESULTS

Compared with controls, the Fabry cohort had 16-fold higher odds of renal leak (6% vs. 52%; OR: 16; 95% CI: 3.30, 162; P < 0.001). Renal leak was associated with higher protein creatinine ratio (P < 0.01) and lower hemoglobin (P = 0.002), but not estimated glomerular filtration rate (P = 0.54). Renal leak, but not plasma vitamin C, was associated with a nonsynonymous single nucleotide polymorphism in vitamin C transporter SLC23A1 (OR: 15; 95% CI: 1.6, 777; P = 0.01).

CONCLUSIONS

Increased prevalence of renal leak in adult men with Fabry disease may result from dysregulated vitamin C renal physiology and is associated with abnormal clinical outcomes and genomic variation.

Safety, Tolerability and Pharmacokinetics of Single-Dose Oral SYHA1402 in Healthy Chinese Subjects

INTRODUCTION

To assess the safety, tolerability and pharmacokinetics of a single dose of SYHA1402 in healthy Chinese subjects.

METHODS

This was a randomized, double-blind, placebo-controlled, single-ascending dose study in healthy subjects. Subjects received a single dose of SYHA1402 25 mg, 50 mg, 100 mg, 200 mg, 400 mg or 800 mg, or matching placebo. Safety and tolerability were assessed throughout the study. The pharmacokinetic (PK) parameters of SYHA1402 were estimated using non-compartmental analysis.

RESULTS

In all, 54 subjects were enrolled and completed the study. Specifically, there were no deaths, serious adverse events or withdrawals from study due to adverse events. All treatment-emergent adverse events were mild. The most common drug-related adverse event was sinus bradycardia. The time to maximum concentration ranged from 1.13 to 2.25 h, and the terminal elimination half-life range was 1.51-4.70 h. SYHA1402 exhibited nonlinear PK parameters with less than dose-proportional increases in exposure after single oral doses of 25 to 800 mg.

CONCLUSION

SYHA1402 administered as a single dose was well tolerated and safe over the dose range of 25-800 mg. More than 50% of the unchanged SYHA1402 was excreted in urine within the dose range of 25-100 mg.

TRIAL REGISTRATION

NCT03988413 ( https://www.

CLINICALTRIALS

gov/ ; registration date: 17 June 2019).

Clinical Relevance of lncRNA and Mitochondrial Targeted Antioxidants as Therapeutic Options in Regulating Oxidative Stress and Mitochondrial Function in Vascular Complications of Diabetes

Metabolic imbalances and persistent hyperglycemia are widely recognized as driving forces for augmented cytosolic and mitochondrial reactive oxygen species (ROS) in diabetes mellitus (DM), fostering the development of vascular complications such as diabetic nephropathy, diabetic cardiomyopathy, diabetic neuropathy, and diabetic retinopathy. Therefore, specific therapeutic approaches capable of modulating oxidative milieu may provide a preventative and/or therapeutic benefit against the development of cardiovascular complications in diabetes patients. Recent studies have demonstrated epigenetic alterations in circulating and tissue-specific long non-coding RNA (lncRNA) signatures in vascular complications of DM regulating mitochondrial function under oxidative stress. Intriguingly, over the past decade mitochondria-targeted antioxidants (MTAs) have emerged as a promising therapeutic option for managing oxidative stress-induced diseases. Here, we review the present status of lncRNA as a diagnostic biomarker and potential regulator of oxidative stress in vascular complications of DM. We also discuss the recent advances in using MTAs in different animal models and clinical trials. We summarize the prospects and challenges for the use of MTAs in treating vascular diseases and their application in translation medicine, which may be beneficial in MTA drug design development, and their application in translational medicine.

Current Approach to the Pathogenesis of Diabetic Cataracts

Cataracts remain the first or second leading cause of blindness in all world regions. In the diabetic population, cataracts not only have a 3–5 times higher incidence than in the healthy population but also affect people at a younger age. In patients with type 1 diabetes, cataracts occur on average 20 years earlier than in the non-diabetic population. In addition, the risk of developing cataracts increases with the duration of diabetes and poor metabolic control. A better understanding of the mechanisms leading to the formation of diabetic cataracts enables more effective treatment and a holistic approach to the patient.

Relevance of Indian traditional tisanes in the management of type 2 diabetes mellitus: a review

Background

Tisanes are a potential source of phytochemicals to reduce disease risk conditions and are used to protect from non-communicable diseases, globally. A few tisanes have gained more popularity than others depending on their chemical composition based on the geographical origin of the used herb. Several Indian tisanes have been claimed to have traits beneficial to people with or at a high risk of type 2 diabetes mellitus. Under the concept, the literature was reviewed and compiled into a document to highlight the chemical uniqueness of popular Indian traditional tisanes to be more informative and potent as per modern medicine to overcome type 2 diabetes mellitus.

Methods

An extensive literature survey was conducted using computerized database search engines, such as Google Scholar, PubMed, ScienceDirect, and EMBASE (Excerpta Medica database) for herbs that have been described for hyperglycemia, and involved reaction mechanism, in-vivo studies as well as clinical efficacies published since 2001 onwards using certain keywords. Compiled survey data used to make this review and all findings on Indian traditional antidiabetic tisanes are tabulated here.

Results

Tisanes render oxidative stress, counter the damage by overexposure of free radicals to the body, affect enzymatic activities, enhance insulin secretion, etc. The active molecules of tisanes also act as anti-allergic, antibacterial, anti-inflammatory, antioxidant, antithrombotic, antiviral, antimutagenicity, anti-carcinogenicity, antiaging effects, etc. WHO also has a strategy to capitalize on the use of herbals to keep populations healthy through effective and affordable alternative means with robust quality assurance and strict adherence to the product specification.

Pomegranate (Punica granatum) peel alleviates lithium-induced alterations in the thyroid gland of rats by modulating apoptosis and oxidative stress

Lithium carbonate (LC) is known to alter thyroid gland function. Pomegranate (PG) is a fruit with multiple antioxidant and antiapoptotic properties. Here, we studied the effect of PG on LC-induced morphological and functional alterations in the thyroid glands of rats. Rats were divided into four groups: control, lithium, lithium-PG, and PG. After 8 weeks, the rats were sacrificed, the levels of thyroid hormones and oxidative stress markers were estimated, and thyroid tissues were subjected to histological, immunohistochemical, and ultrastructural evaluations. Compared to the control group, the lithium group showed significant changes in thyroid hormone levels, greater expression of the oxidant marker malondialdehyde, and lower expression of the antioxidant marker superoxide dismutase (SOD). Most of these changes improved upon PG treatment. Histological evaluation of the thyroid in the lithium group showed disorganization and follicle involution. Additionally, the periodic acid Schiff staining intensity and SOD immunoreactivity declined significantly, whereas the collagen fiber content and Bax immunoreactivity increased. The follicular ultrastructure showed marked distortion. These changes were mitigated upon PG treatment. In conclusion, PG alleviated the morphological and functional changes in the thyroid glands induced by LC by modulating apoptosis and oxidative stress.

Role of Oxidative Stress in Ocular Diseases: A Balancing Act

Redox homeostasis is a delicate balancing act of maintaining appropriate levels of antioxidant defense mechanisms and reactive oxidizing oxygen and nitrogen species. Any disruption of this balance leads to oxidative stress, which is a key pathogenic factor in several ocular diseases. In this review, we present the current evidence for oxidative stress and mitochondrial dysfunction in conditions affecting both the anterior segment (e.g., dry eye disease, keratoconus, cataract) and posterior segment (age-related macular degeneration, proliferative vitreoretinopathy, diabetic retinopathy, glaucoma) of the human eye. We posit that further development of therapeutic interventions to promote pro-regenerative responses and maintenance of the redox balance may delay or prevent the progression of these major ocular pathologies. Continued efforts in this field will not only yield a better understanding of the molecular mechanisms underlying the pathogenesis of ocular diseases but also enable the identification of novel druggable redox targets and antioxidant therapies.

Effects of Exercise On Coronary Flow Reserve And Biochemical Parameters in Patients With Type 2 Diabetes Mellitus

The most important mortality and morbidity causes in diabetic patients are coronary, peripheral and cerebral diseases. The aim of our study was to noninvasively determine dysfunction in epicardial coronary arteries and microvascular circulation with measurement of coronary flow reserve using transthoracic echocardiography in patients with type 2 diabetes despite absence of ischemic symptoms, and to demonstrate the amelioration in endothelial functions, glycemic control and insulin resistance along with increase in coronary flow reserve after 8 weeks of regular exercise. 40 patients diagnosed with type 2 diabetes in Istanbul Facuty of Medicine, Department of Diabetes, who were on follow-up for at least three years due to diabetes, without ischemic symptoms and 20 healthy subjects took part in study. Basal values before exercise of diabetic patients who were included in the exercise program were compared with basal values of diabetic patients who did not exercise regularly. To summarize, regular exercise and physical activity are highly important in diabetic patients for primary and secondary protection against cardiovascular incidents. Physical activity increases insulin sensitivity in diabetic patients, and has many positive effects on glucose metabolism. It is the important way to decrease obesity and visceral fat tissue. There is evidence pointing out that regular exercise can defer or even prevent initiation of diabetes.

In Vitro Modeling of Diabetes Impact on Vascular Endothelium: Are Essentials Engaged to Tune Metabolism?

Angiopathy is a common complication of diabetes mellitus. Vascular endothelium is among the first targets to experience blood-borne metabolic alterations, such as hyperglycemia and hyperlipidemia, the hallmarks of type 2 diabetes. To explore mechanisms of vascular dysfunction and eventual damage brought by these pathologic conditions and to find ways to protect vasculature in diabetic patients, various research approaches are used including in vitro endothelial cell-based models. We present an analysis of the data available from these models that identifies early endothelial cell apoptosis associated with oxidative stress as the major outcome of mimicking hyperglycemia and hyperlipidemia in vitro. However, the fate of endothelial cells observed in these studies does not closely follow it in vivo where massive endothelial damage occurs mainly in the terminal stages of diabetes and in conjunction with comorbidities. We propose that the discrepancy is likely in missing essentials that should be available to cultured endothelial cells to adjust the metabolic state and withstand the immediate apoptosis. We discuss the role of carnitine, creatine, and AMP-activated protein kinase (AMPK) in suiting the endothelial metabolism for long-term function in diabetic type milieu in vitro. Engagement of these essentials is anticipated to expand diabetes research options when using endothelial cell-based models.

Kotian S, Manjrekar P, Shastry R, D’Souza V. The ABC (HbA1c, blood pressure and LDL-cholesterol) of diabetes and oxidative stress: knowing the links

Introduction and Aim: Large body of evidence suggests that oxidative stress has a crucial role to play in diabetes and its related complications. In the present research we have tried to determine potential risk factors for oxidative stress in type 2 diabetes by conducting a cross-sectional study.   Materials and Methods: We studied 238 patients with or without complications of diabetes, aged 40-75 years. Blood samples were analysed for fasting plasma glucose, glycated haemoglobin, malondialdehyde, total cholesterol, triglyceride, LDL-cholesterol and HDL-cholesterol. Each patient’s waist circumference, BMI, blood pressure was measured.   Results: Participants mean age was 57.5 ± 8.9 years. Logistic regression analysis identified glycated haemoglobin (95% CI: 1.02-1.92; p=0.04), hypertension (95% CI: 0.99-4.08; p=0.05) and LDL-cholesterol (95% CI: 1.12-5.87; p=0.03) as independent risk factors for oxidative stress. Other contributors were age and presence of complications like nephropathy, retinopathy, peripheral neuropathy and macrovascular disease in diabetes.   Conclusion: Our data demonstrate that ‘ABCs of diabetes’ namely HbA1c, blood pressure and LDL-cholesterol are independent risk factors for oxidative stress. Oxidative stress aggravates with age and presence of complications. It appears important to achieve a good ABC goal to bring down oxidative stress in diabetes.

Higher NADH Dehydrogenase [Ubiquinone] Iron–Sulfur Protein 8 (NDUFS8) Serum Levels Correlate with Better Insulin Sensitivity in Type 1 Diabetes

Objective: The aim of the study was to evaluate NADH dehydrogenase [ubiquinone] iron–sulfur protein 8 (NDUFS8) serum concentration as a marker of Complex I, and the relationship with insulin resistance in type 1 diabetes mellitus (T1DM). Design and methods: Participants were adults with T1DM, recruited over the course of 1 year (2018–2019). NDUFS8 protein serum concentration was measured using the ELISA test. Insulin resistance was evaluated with indirect marker estimated glucose disposal rate (eGDR). The group was divided on the base of median value of eGDR (higher eGDR—better insulin sensitivity). Results: The study group consists of 12 women and 24 men. Medians of eGDR and NDUFS8 protein concentration are 7.6 (5.58–8.99) mg/kg/min and 2.25 (0.72–3.81) ng/mL, respectively. The group with higher insulin sensitivity has higher NDUFS8 protein serum concentration, lower waist to hip ratio (WHR), body mass index (BMI), and they are younger. A negative correlation is observed between NDUFS8 protein serum concentration and WHR (rs = −0.35, p = 0.03), whereas a positive correlation is observed between NDUFS8 protein serum concentration and eGDR (rs = 0.43, p = 0.008). Univariate logistic regression shows a significant association between insulin sensitivity and lower age, as well as a higher NDUFS8 serum level. A multivariate logistic regression model confirms the significance (AOR 2.38 (1.04–5.48). p = 0.042). Multivariate linear regression confirms a significant association between insulin sensitivity and better mitochondrial function (beta = 0.54, p = 0.003), independent of age, duration of diabetes, and smoking. Conclusions: Higher NDUFS8 protein serum concentration is associated with higher insulin sensitivity among adults with T1DM.

Impact of SGLT2 inhibitors on the kidney in people with type 2 diabetes and severely increased albuminuria

INTRODUCTION

Diabetes is the most common cause of end stage kidney disease. Therapies such as sodium-glucose co-transporter-2 inhibitors have been identified over the last decade as effective oral hypoglycemic agents that also confer additional cardio and kidney protection. Knowledge of their mechanism of action and impact on patients with diabetes and albuminuria is vital in galvanizing prescriber confidence and increasing clinical uptake.

AREAS COVERED

This manuscript discusses the pathophysiology of diabetic kidney disease, patho-physiological mechanisms for sodium-glucose co-transporter-2 inhibitors, and their impact on patients with Type 2 diabetes mellitus and albuminuric kidney disease.

EXPERT OPINION

Sodium-glucose co-transporter-2 inhibitors reduce albuminuria with consequent benefits on cardiovascular and kidney outcomes in patients with diabetes and severe albuminuria. Whilst they have been incorporated into guidelines, the uptake of these agents into clinical practice has been slow. Increasing the uptake of these agents into clinical practice is necessary to improve outcomes for the large number of patients with diabetic kidney disease globally.

Abnormal urinary loss of vitamin C in diabetes: prevalence and clinical characteristics of a vitamin C renal leak

BACKGROUND

Diabetes is associated with low plasma vitamin C concentrations.

OBJECTIVES

We investigated the contribution of dysregulated vitamin C renal physiology, its prevalence, and associated clinical characteristics.

METHODS

An essential prerequisite was determination of normal vitamin C renal threshold, the plasma concentration at which vitamin C first appears in urine. Using data from 17 healthy participants who underwent vitamin C depletion-repletion studies with a vitamin C dose range of 15-1250 mg daily, renal threshold was estimated using physiology-based pharmacokinetics modeling. Applying renal threshold 95% CIs, we estimated the minimal elimination threshold, the plasma concentration below which no vitamin C was expected in urine of healthy people. Renal leak was defined as abnormal presence of vitamin C in urine with plasma concentrations below the minimal elimination threshold. Criteria were tested in a cross-sectional cohort study of individuals with diabetes (82) and nondiabetic controls (80) using matched plasma and urine samples.

RESULTS

Vitamin C renal thresholds in healthy men and women were [mean (SD)] 48.5 (5.2) µM and 58.3 (7.5) µM, respectively. Compared with nondiabetic controls, participants with diabetes had significantly higher prevalence of vitamin C renal leak (9% compared with 33%; OR: 5.07; 95% CI: 1.97, 14.83; P < 0.001) and 30% lower mean plasma vitamin C concentrations (53.1 µM compared with 40.9 µM, P < 0.001). Fasting plasma glucose, glycosylated hemoglobin A1c, BMI, micro/macrovascular complications, and protein/creatinine ratio were predictive of vitamin C renal leak.

CONCLUSIONS

Increased prevalence of vitamin C renal leak in diabetes is associated with reduced plasma vitamin C concentrations. Glycemic control, microvascular complications, obesity, and proteinuria are predictive of renal leak.

Insulin and Zinc Co-Administration Ameliorate Diabetes Mellitus-Induced Reproductive Dysfunction in Male Rats

Impaired male reproductive function is a major complication associated with diabetes mellitus (DM). Whether or not insulin, when co-administered with zinc will reverse or ameliorate reproductive dysfunction in male diabetics is not known. This study thus sought to establish if co-administration of insulin and zinc reverses or ameliorates male reproductive dysfunction in DM better than either insulin or zinc. Five (5) normal and twenty (20) diabetic sexually mature rats were assigned into five groups of five animals each. Group A consisted of normal rats and had access to only food and water. Group B consisted of diabetic animals with no treatment and served as DM control. Groups C and D consisted of diabetic animals and received insulin and zinc respectively. Group E consisted of diabetic animals and received both insulin and zinc. All diabetic animals had free access to food and water. Insulin in all cases was given subcutaneously twice daily in the morning and evening at 1 unit and 4 units respectively. Zinc (10mg/kg) was given orally once daily. Treatments in all cases commenced two weeks after DM was confirmed. The treatment lasted ten days. Samples were thereafter collected for analyses. DM decreased sperm count, sperm motility, sperm viability, normal sperm cells, semen pH, serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone, while increasing sperm cells with defective tails. DM also impaired testicular morphology. Insulin and zinc co-administration improved sperm viability, sertoli cell count, Johnsen's score, serum FSH, LH and testosterone. Co-administration also improved semen pH towards normal. Insulin or zinc ameliorated several aspects of DM-induced male sexual dysfunction. However, the co-administration of insulin and zinc provided better results.

Serum uric acid levels and diabetic kidney disease in patients with type 2 diabetes mellitus: A dose-response meta-analysis

OBJECTIVE

Our study aimed to assess the existing evidence on whether serum uric acid (SUA) levels are associated with diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a systematic search of articles up to October 2021 in Medline, Embase, The Cochrane Library and Web of Science that estimated DKD by SUA levels in patients with T2DM. Pooled relative risks with 95% CI were calculated using random effects models RESULTS: A total of eight cohort studies involving 25,741 T2DM patients were included. Meta-analysis showed that compared the highest with the lowest category of SUA level, the summary risk ratios were 2.04 (95%CI 1.43-2.92, P < 0.001). The linear dose-response analysis revealed that the risk of DKD increased by 24% for each 1 mg/dl increase of SUA. The non-linear dose-response analysis also showed a significant relevance between SUA and the risk of DKD in patients with type 2 diabetes mellitus (P < 0.001).

CONCLUSIONS

Serum uric acid is associated with an increased risk of diabetic kidney disease in patients with type 2 diabetes mellitus. Serum uric acid level could be a good indicator for predicting diabetic kidney disease in patients with type 2 diabetes mellitus.

The role of Pycnogenol in the control of inflammation and oxidative stress in chronic diseases: Molecular aspects

The prevalence of chronic diseases has increased significantly with the rising trend of sedentary lifestyles, reduced physical activity, and dietary modifications in recent decades. Inflammation and oxidative stress play a key role in the pathophysiology of several chronic diseases, such as type II diabetes, cardiovascular diseases, and hepatic conditions. Therefore, reducing inflammation and oxidative stress may be beneficial in the prevention and treatment of various chronic disorders. Since chronic diseases are not completely curable, various methods have been proposed for their control. Complementary therapies and the use of natural antioxidant and antiinflammatory compounds are among these novel approaches. Pycnogenol (PYC) is a natural compound that could control inflammation and oxidative stress. Furthermore, some previous studies have shown that PYC could effectively reduce inflammation through signaling the downstream of insulin receptors, inhibiting the phosphorylation of the serine residues of insulin receptor substrate-1, reducing pro-inflammatory cytokines and oxidative stress indices through the stimulation of antioxidant pathways, increasing free radical scavenging activities, preventing lipid peroxidation, and protecting the erythrocytes in glucose-6-phosphate dehydrogenase-deficient individuals, although these effects have not been fully proved. The present study aimed to comprehensively review the evidence concerning the positive physiological and pharmacological properties of PYC, with an emphasis on the therapeutic potential of this natural component for enhancing human health.

Phenolic Constituents, Antioxidant and Cytoprotective Activities, Enzyme Inhibition Abilities of Five Fractions from Vaccinium dunalianum Wight

The bud of Vaccinium dunalianum Wight has been traditionally consumed as health herbal tea by “Yi” people in Yunnan Province, China, which was locally named “Que Zui tea”. This paper studied the chemical constituents of five fractions from Vaccinium dunalianum, and their enzyme inhibitory effects of α-glucosidase and pancreatic lipase, antioxidant activity, and cytoprotective effects on H₂O₂-induced oxidative damage in HepG2 cells. The methanol extract of V. dunalianum was successively partitioned with petroleum ether (PF), chloroform (CF), ethyl acetate (EF), n-butanol (BF), and aqueous (WF) to obtain five fractions. The chemical profiling of the five fractions was analyzed by ultra-high-performance liquid chromatography coupled with a tandem mass spectrometry (UHPLC-MS/MS), and 18 compounds were tentatively identified. Compared to PF, CF, BF and WF, the EF revealed the highest total phenols (TPC) and total flavonoids (TFC), and displayed the strongest enzyme inhibition ability (α-glucosidase and pancreatic lipase) and antioxidant capacity (DPPH, ABTS and FRAP). Furthermore, these five fractions, especially EF, could effectively inhibit reactive oxygen species (ROS) production and cell apoptosis on H₂O₂-induced oxidative damage protection in HepG2 cells. This inhibitory effect might be caused by the up-regulation of intracellular antioxidant enzyme activity (CAT, SOD, and GSH). The flavonoids and phenolic acids of V. dunalianum might be the bioactive substances responsible for enzyme inhibitory, antioxidant, and cytoprotective activities.

Antilipidemic and Hepatoprotective Effects of Ethanol Extract of Justicia spicigera in Streptozotocin Diabetic Rats

Oxidative stress is a factor that contributes to the development of complications in diabetes; however, its effects can be counteracted using exogenous antioxidants that are found in some plants, which is why people turn to traditional medicines in the search for therapeutic treatment. Justicia spicigera has been demonstrated to have the capacity to reduce glycemic levels; however, its effects on non-insulin-dependent organs such as the liver have not been reported. During 30 days of administration of Justicia spicigera ethanol extract, the blood glucose and weight of rats were measured every 5 days. Once the treatment was concluded, the rats were sacrificed. Corporal weight, blood glucose, cholesterol, very-low-density lipoprotein (VLDL), triglycerides, total lipids, and liver profile were reduced in the diabetic condition and normalized with the application of ethanol extract from J. spicigera (EJS). Additionally, there was a significant increase in catalase and superoxide dismutase activity in the control diabetic rats, a decrease in their activity with the extract administration, and no effect on normoglycemic rats. In conclusion, EJS is considered to be capable of reducing oxidative stress by maintaining diminished lipid and liver function profiles in male Wistar rats with streptozotocin-induced diabetes.

The Role of Different Retinal Imaging Modalities in Predicting Progression of Diabetic Retinopathy: A Survey

Diabetic retinopathy (DR) is a devastating condition caused by progressive changes in the retinal microvasculature. It is a leading cause of retinal blindness in people with diabetes. Long periods of uncontrolled blood sugar levels result in endothelial damage, leading to macular edema, altered retinal permeability, retinal ischemia, and neovascularization. In order to facilitate rapid screening and diagnosing, as well as grading of DR, different retinal modalities are utilized. Typically, a computer-aided diagnostic system (CAD) uses retinal images to aid the ophthalmologists in the diagnosis process. These CAD systems use a combination of machine learning (ML) models (e.g., deep learning (DL) approaches) to speed up the diagnosis and grading of DR. In this way, this survey provides a comprehensive overview of different imaging modalities used with ML/DL approaches in the DR diagnosis process. The four imaging modalities that we focused on are fluorescein angiography, fundus photographs, optical coherence tomography (OCT), and OCT angiography (OCTA). In addition, we discuss limitations of the literature that utilizes such modalities for DR diagnosis. In addition, we introduce research gaps and provide suggested solutions for the researchers to resolve. Lastly, we provide a thorough discussion about the challenges and future directions of the current state-of-the-art DL/ML approaches. We also elaborate on how integrating different imaging modalities with the clinical information and demographic data will lead to promising results for the scientists when diagnosing and grading DR. As a result of this article's comparative analysis and discussion, it remains necessary to use DL methods over existing ML models to detect DR in multiple modalities.

Folate derivatives, 5-methyltetrahydrofolate and 10-formyltetrahydrofolate, protect BEAS-2B cells from high glucose-induced oxidative stress and inflammation

Folate (vitamin B₉) and its biologically active derivatives are well-known antioxidant molecules protecting cells from oxidative degradation. The presence of high glucose, often found in diabetic patients, causes oxidative stress resulting in cellular stress and inflammatory injury. Cells in organs such as the lung are highly prone to inflammation, and various protective mechanisms exist to prevent the progressive disorders arising from inflammation. In the present study, the synthetic form of folate, i.e. folic acid, and active forms of folate, i.e. 5-methyltetrahydrofolate and 10-formyltetrahydrofolate, were evaluated for their antioxidant and antiinflammatory potential against high glucose (50 mM)–mediated oxidative stress and inflammation in BEAS-2B cells, an immortalised bronchial epithelial cell line. High glucose treatment showed a 67% reduction in the viability of BEAS-2B cells, which was restored to the viability levels seen in control cultures by the addition of active folate derivatives to the culture media. The DCFH-DA fluorometric assay was performed for oxidative stress detection. The high glucose–treated cells showed a significantly higher fluorescence intensity (1.81- and 3.8-fold for microplate assay and microscopic observation, respectively), which was normalised to control levels on supplementation with active folate derivatives. The proinflammatory NF-κB p50 protein expression in the active folate derivative–supplemented high glucose–treated cells was significantly lower compared to the folic acid treatment. In support of these findings, in silico microarray GENVESTIGATOR database analysis showed that in bronchiolar small airway epithelial cells exposed to inflammatory condition, folate utilization pathway genes are largely downregulated. However, the folate-binding protein gene, which encodes to the folate receptor 1 (FOLR1), is significantly upregulated, suggesting a high demand for folate by these cells  in inflammatory situations. Supplementation of the active folate derivatives 5-methyltetrahydrofolate and 10-formyltetrahydrofolate resulted in significantly higher protection over the folic acid from high glucose–induced oxidative stress and inflammation. Therefore, the biologically active folate derivatives could be a suitable alternative over the folic acid for alleviating inflammatory injury-causing oxidative stress.

A brief review of vitamin D as a potential target for the regulation of blood glucose and inflammation in diabetes-associated periodontitis

Diabetes is a metabolic disorder associated with various complications, including periodontitis. The risk of periodontitis is increased in patients with diabetes, while vitamin D deficiency is associated with both diabetes and periodontitis. Thus, there is a need to identify the molecular effects of vitamin D on the regulation of inflammation and glucose in diabetes-associated periodontitis. The Web of Science, Scopus, and PubMed databases were searched for studies of the molecular effects of vitamin D. Molecular effects were reportedly mediated by salivary secretions, interactions of advanced glycation end products (AGEs) with receptors of AGEs (RAGEs), cytokines, and oxidative stress pathways linking diabetes with periodontitis. Vitamin D supplementation attenuates inflammation in diabetes-associated periodontitis by reducing the levels of inflammatory cytokines and numbers of immune cells; it also has antibacterial effects. Vitamin D reduces cytokine levels through regulation of the extracellular signal-related kinase 1/2 and Toll-like receptor 1/2 pathways, along with the suppression of interleukin expression. Glucose homeostasis is altered in diabetes either because of reduced insulin production or decreased insulin sensitivity. These vitamin D-related alterations of glucoregulatory factors may contribute to hyperglycaemia; hyperglycaemia may also lead to alterations of glucoregulatory factors. This review discusses the pathways involved in glucose regulation and effects of vitamin D supplementation on glucose regulation. Further studies are needed to characterise the effects of vitamin D on diabetes-associated periodontitis.

Association Between Insulin Resistance, Oxidative Stress, Sympathetic Activity and Coronary Microvascular Function in Patients With Early Stage Impaired Glucose Metabolism

BACKGROUND

Although acute hyperglycemia and insulin resistance (IR) are risk factors for atherosclerosis development through oxidative stress and sympathetic activation in diabetes mellitus, the association of these factors with coronary microvascular function in the early diabetic stage remains controversial.

METHODS AND RESULTS

Using transthoracic echocardiography, coronary flow velocity (CFV) and its reserve (CFVR) as parameters of coronary microvascular function were measured before and 1 h after an oral glucose tolerance test (OGTT) in 40 patients (aged 59±12 years) without diagnosed diabetes mellitus or coronary artery disease. Plasma glucose, insulin and thiobarbituric acid reactive substance (TBARS; an oxidative stress marker) were measured during the OGTT. IR was evaluated as homeostasis model assessment of IR (HOMA-R). Sympathetic activity was evaluated by using plasma catecholamines after OGTT. CFVR decreased after an OGTT (P<0.0001) mainly because of an increased baseline CFV (P<0.0001). Although the change in CFVR was not associated with the change in TBARS and catecholamines, it was independently associated with HOMA-R on the multivariate regression analysis (β=-0.40, P=0.01). Another multivariate regression analysis revealed that change in baseline CFV was independently associated with HOMA-R (β=0.35, P=0.03).

CONCLUSIONS

IR, rather than oxidative stress and sympathetic activity, was associated with an increase in baseline CFV and a decline in CFVR during acute hyperglycemia. IR might play an important role in increased myocardial oxygen demand and coronary microvascular dysfunction.

Quality Control, Anti-Hyperglycemic, and Anti-Inflammatory Assessment of Colvillea racemosa Leaves Using In Vitro, In Vivo Investigations and Its Correlation with the Phytoconstituents Identified via LC-QTOF-MS and MS/MS

Colvillea racemosa is a cultivated ornamental plant that is a monotypic genus of Fabaceae. It is native to Madagascar, with limited studies. For the first time, the leaf quality control parameters, the anti-hyperglycemic and anti-inflammatory in vitro activity of Colvillea racemosa ethanol extract (CRE) and its fractions of petroleum ether (CRP), methylene chloride (CRMC), ethyl acetate (CREA), n-butanol (CRB), and methanol (CRME) were evaluated. It exhibited significant inhibition against α-amylase, α-glucosidase and membrane stabilization. CRB was the most active fraction, and in vivo studies revealed that oral treatment with CRB of STZ-induced diabetic rats efficiently lowered blood glucose by 67.78%, reduced serum nitric oxide and lipid peroxide levels by 41.23% and 38.45%, respectively, and increased the GSH level by 90.48%. In addition, compared with the diabetic group, there was a 52.2% decrease in serum VCAM, a 55.5% increase in paraoxonase, an improved lipid profile, and improved liver and kidney functions for a treated diabetic group with CRB. Metabolite profiling of CRB was determined by UPLC-ESI-QTOF-MS and tandem MS/MS. Twenty-three chromatographic peaks were identified, which were classified into phenolic compounds and amino acids. The characterized flavonoids were apigenin and luteolin derivatives.

Rosa centifolia petal extract induces endothelium-dependent and endothelium-independent vasorelaxation in rat aorta and prevents accumulation of inflammatory factors in human umbilical vein endothelial cells

This study aims to investigate the vasorelaxation effects of a Rosa centifolia petal extract (ROSE CRYSTA®-70: ROSE-70) on the isolated aorta and the protective effect of ROSE-70 on human umbilical vein endothelial cells (HUVECs) dysfunction. ROSE-70 inhibited phenylephrine (PE) -induced contraction in an endothelium-dependent and endothelium-independent manner; however, this relaxation was lower in the endothelium-denuded aorta. ROSE-70-induced relaxation was attenuated by L-N^G -nitroarginine methyl ester (L-NAME), a nitric oxide synthase inhibitor in the endothelium-intact aorta. Moreover, the relaxation in the endothelium-denuded aorta in response to increases in cAMP was inhibited by SQ22536, an adenylate cyclase inhibitor, and this relaxation was also attenuated by 4-aminopyridine, a voltage-activated K⁺ channel inhibitor. ROSE-70 contains high concentrations of quercetin, rutin, and other compounds. Pure quercetin and rutin also inhibited PE-induced contraction in an endothelium-dependent manner, although rutin-induced relaxation was milder in the endothelium-denuded aorta. ROSE-70 significantly increased the phosphorylation (at Ser1177) of eNOS in HUVECs. Moreover, ROSE-70 potently suppressed high glucose- and H₂ O₂ -induced accumulation of tumor necrosis factor-α (TNF-α) and nuclear factor-kappa B (NF-κB) were investigated in human umbilical vein endothelial cells (HUVECs). In this study, we defined the mechanism of ROSE-70-induced vasorelaxation in rat aorta and demonstrated that ROSE-70 has anti-inflammatory effects in endothelial cells. PRACTICAL APPLICATIONS: Endothelial cells play a role in vascular homeostasis. Endothelial dysfunction is caused by a variety of risk factors such as hypertension, arteriosclerosis, hyperglycemia, and oxidative stress. ROSE-70 is a food ingredient and the powdered form of an extract from the rose petal with >70% of the content corresponding to rose petal polyphenols such as rutin, quercetin, and protocatechuic acid. This study revealed that vasorelaxation effects of ROSE-70 and the protective role of ROSE-70 on the dysfunction of endothelial cells by high glucose and superoxides were investigated for the first time. We showed the mechanisms of ROSE-70- induced endothelium-dependent vasorelaxation and the protective effects of endothelial cells from high glucose and superoxide. ROSE-70 has been shown to have antiaging, skin elasticity-enhancing, skin-lightening, anti-allergic, sugar-absorbing, and lipolytic effects (URL: https://www.toyohakko-healthcare. com/en/rose_crysta70/). Therefore, the authors believe that ROSE-70 is an excellent food ingredient that has preventive and antiaging effects on lifestyle-related diseases.