Oxidative stress in diabetes: implications for vascular and other complications

Enhanced diabetic foot ulcer treatment with a chitosan-based thermosensitive hydrogel loaded self-assembled multi-functional nanoparticles for antibacterial and angiogenic effects

Inhibiting bacterial growth and promoting angiogenesis are essential for enhancing wound healing in diabetic patients. Excessive oxidative stress at the wound site can also lead to an accumulation of reactive oxygen species. To address these challenges, a smart thermosensitive hydrogel loaded with therapeutic agents was developed. This formulation features self-assembled nanoparticles named CIZ, consisting of chlorogenic acid (CA), indocyanine green (ICG), and zinc ions (Zn2+). These nanoparticles are loaded into a chitosan-β-glycerophosphate hydrogel, named CIZ@G, which enables rapid gel formation under photothermal effects. The hydrogel demonstrates good biocompatibility and effectively releases drugs into diabetic foot ulcers (DFU) wound. Benefiting from the dual actions of CA and zinc ions, the hydrogel exhibits potent antioxidative and anti-inflammatory effects, enhances the expression of vascular endothelial growth factor (VEGF) and Platelet endothelial cell adhesion molecule-1 (CD31), and promotes angiogenesis. Both in vitro and in vivo experiments confirm that CIZ@G can effectively inhibit the growth of Staphylococcus aureus post-laser irradiation and accelerate wound remodeling within 14 days. This approach offers a new strategy for the treatment of diabetic foot ulcers (DFU), potentially transforming patient care in this challenging clinical area.

COVID-19 vaccines and blood glucose control: Friend or foe?

PURPOSE

To overview the recent literature regarding the relationship between COVID-19 vaccines and glycemic control.

METHODS

Data were extracted from text and tables of all available articles published up to September 2023 in PubMed Database describing glucose homeostasis data in subjects exposed to COVID-19 vaccines, focusing on patients with diabetes mellitus (DM).

RESULTS

It is debated if the immune system impairment observed in diabetic patients makes them susceptible to lower efficacy of vaccines, but evidence suggests a possible improvement in immune response in those with good glycemic control. Despite their proven protective role lowering infection rates and disease severity, COVID-19 vaccines can result in diabetic ketoacidosis, new-onset diabetes, or episodes of hyper- or hypoglycemia.

CONCLUSIONS

Evidence with COVID-19 vaccines highlights the strong relationship existing between DM and immune system function. Clinicians should strive to achieve optimal glucose control before vaccination and promptly manage possible glucose homeostasis derangement following vaccine exposure.

Role of miR-125b-5p in modulating placental SIRT7 expression and its implications for lipid metabolism in gestational diabetes

Gestational diabetes is marked impaired glucose tolerance, poses various adverse outcomes including increased BMI and obesity. These outcomes results from excess lipid accumulation which is marked by elevated triglycerides. In GDM, placenta exhibits altered lipid metabolism, including reduced fatty acid oxidation and increased triglyceride accumulation. These elevated triglycerides can also contribute to oxidative stress in GDM. SIRT7 plays an important role in regulating lipid metabolism and triglycerides levels. This study aimed to investigate the potential of miRNA to regulate the placental SIRT7 in GDM. PCR analysis reveals that SIRT7 expression along with oxidative stress markers elevated in GDM placenta. These elevated SIRT7 levels were positively correlated with BMI and triglycerides levels in GDM subjects. miR-125b-5p was identified to regulate SIRT7 mRNA using in-silico approaches. Expression levels of miR-125b-5p were found to be downregulated in GDM placenta and found to be negatively correlated with SIRT7 mRNA expression. To confirm the hypothesis BeWo cells were transfected with anti-miR-125b and miR-125b-mimic. Anti-miR overexpressed the SIRT7 expression where mimic dysregulated it. Additionally, overexpressing miR-125b-5p controlled the elevated SIRT7 caused by the exposure of high glucose in BeWo cells. Collectively this study indicated that miR-125b-5p may regulate lipid metabolism via SIRT7 contributing to GDM. These findings highlights the warrant of further research to develop the therapeutic approaches that target miR-125b-5p to reduce lipid accumulation and obesity in GDM.

Glucose-Responsive Insulin Delivery via Surface-Functionalized Titanium Dioxide Nanoparticles: A Promising Theragnostic against Diabetes Mellitus

Glucose-dependent insulin delivery systems have been recognized as a promising approach for controlling blood sugar levels in individuals with diabetes mellitus (DM). Recently, titanium dioxide nanoparticles have garnered huge attention in scientific research for their small size and effective drug delivery capabilities. In this study, we developed alizarin (AL)-capped phenylboronic acid (PBA)-functionalized titanium dioxide nanoparticles (TiO2) for glucose-sensitive insulin delivery (TiO2-PBA-INS-AL) aiming to manage both blood sugar levels and its associated organ pathology in DM. The synthesized nanoparticles demonstrated favorable loading capacity as well as high insulin encapsulation efficiency. Initial studies demonstrated glucose-responsive insulin release from TiO2-PBA-INS-AL in a cell-free environment upon exposure to different glucose concentrations. Notably, in vitro experiments revealed that insulin release from TiO2-PBA-INS-AL was more effective in muscle cells (primary glucose storage cells) compared to lung cells when subjected to different glucose concentrations (5.5-25 mM), indicating a glucose-sensitive intracellular insulin delivery mechanism. Furthermore, treatment with TiO2-PBA-INS-AL significantly enhanced GLUT4 translocation and glucose utilization in muscle cells treated with sodium palmitate (PA, 0.75 mM), compared to treatments with TiO2 or insulin alone. In diabetic animal models, a single oral dose of TiO2-PBA-INS-AL maintained normoglycemia for up to 12 h, indicating a significant improvement over subcutaneous or oral insulin treatment. Oral administration of TiO2-PBA-INS-AL also increased insulin bioavailability in both serum and muscle tissue compared to other administration methods. Besides, TiO2-PBA-INS-AL treatment showed no toxicity against both in vitro and in vivo models. Taken together, this nanocarrier-based drug delivery system mimics the natural regulation of insulin secretion in a noninvasive manner, enhancing patient adherence, reducing the risk of hyperglycemia, and improving diabetes management.

Respiratory dysfunction in old mice could be related to inflammation and lung fibrosis induced by hyperphosphatemia

BACKGROUND

With age, lungs undergo typical changes that lead to a deterioration of respiratory function. Our aim was to assess the role of age-associated hyperphosphatemia in these changes.

METHODS

We used C57BL6 mice to study an ageing model in vivo and human lung fibroblasts were treated with a phosphate donor, beta-glycerophosphate (BGP), to explore mechanisms involved. Respiratory function was registered with a double chamber plethysmograph. Lung structure was analysed by different staining, phosphate and cytokines levels by colorimeric kits, expression of fibrosis, inflammation and ET-1 system by western blot or RT-PCR.

RESULTS

Old mice showed hyperphosphatemia, along with lung fibrosis, loss of elastin, increased expression of pro-inflammatory cytokines and impaired respiratory function. BGP induced inflammation and fibrosis in fibroblasts through the activation and binding of NFkB to the MCP-1 or FN promoters. BGP increased ECE-1 expression by inducing NFkB binding to the ECE-1 promoter. QNZ, an NFkB inhibitor, blocked these effects. When ECE-1 was inhibited with phosphoramidon, BGP-induced inflammation and fibrosis were significantly reduced, suggesting a role for ET-1 in BGP-mediated effects.ET-1 produced effects similar to those of BGP, which were also dependent on NFkB. To study the pathophysiological relevance of hyperphosphatemia in vivo, a low-P diet was administered to a group of old animals, showing an improvement in fibrosis, inflammation and respiratory function compared to old mice on a standard diet.

CONCLUSION

These results suggest that age-related hyperphosphatemia induces inflammation, fibrosis, and impaired respiratory function in old mice; these effects appear to be mediated by ET-1 and NFkB activation.

Surface-Functionalized Nanoceria: Dual Action in Diabetes Management via Glucose-Responsive Insulin Delivery and Oxidative Stress Mitigation

Nanoceria (NC) is gaining scientific attention due to its widespread drug delivery efficacy and modulation of oxidative stress. Herein, we developed dextran (Dex) capped insulin (INS)-loaded phenylboronic acid (PBA)-functionalized nanoceria (NC-PBA-INS-Dex) for glucose-responsive insulin delivery and mitigating excessive ROS production to regulate both hyperglycemia and oxidative stress in diabetes mellitus (DM). The prepared nanoparticle showed favorable loading capacity and excellent encapsulation efficiency of insulin. Glucose-responsive insulin release from NC-PBA-INS-Dex was observed initially in the cell-free mode when subjected to varying glucose concentrations (5.5, 11, and 25 mM). Interestingly, under in vitro setting, promising insulin release from NC-PBA-INS-Dex was found in muscle cells (major glucose storage cells) compared to lung cells against exposure to different glucose concentration suggesting a glucose-sensitive intracellular insulin delivery. NC-PBA-INS-Dex treatment further upregulated GLUT4 translocation and glucose uptake/utilization in sodium palmitate-exposed muscle cells, and results were significantly higher compared to NC or INS alone treated cells. Studies in diabetic animals demonstrated the maintenance of normoglycemia for up to 12 h upon gavaging a single dose of NC-PBA-INS-Dex compared to INS alone treatment (subcutaneous/oral). Oral administration of NC-PBA-INS-Dex also increased insulin bioavailability (in both serum and muscle tissue) compared with either subcutaneous or oral insulin administration. NC-PBA-INS-Dex further exhibited ROS scavenging (superoxide radical) potential in cell-free, in vitro, and in vivo systems, and results were comparable to treatment with NC alone. NC-PBA-INS-Dex could effectively regulate the expression of occludin and induce the reversible opening of a tight junction in intestinal epithelial cells, allowing the particle transport through the intestinal mucosa. Treatment with NC-PBA-INS-Dex did not exhibit any toxicity to in vitro and in vivo models. The NC-based drug delivery system will mimic the physiological regulation of insulin secretion in a noninvasive manner, offering improved patient compliance, reduced risk of hyperglycemia, and enhanced overall management of DM.

Nigella sativa L. and its bioactive and nutraceutical components in the management of diabetic peripheral neuropathy

Diabetes-induced hyperglycemia leads to excessive production of oxygen free radicals, inflammatory cytokines, and oxidative stress, which initiates diabetic peripheral neuropathy (DPN). Currently, this condition affects 20% of adults with diabetes. Despite significant advances in the treatment of diabetes, the incidence of its complications, including DPN, is still high. Thus, there is a growing research interest in developing more effective and treatment approaches with less side effects for diabetes and its complications. Nigella sativa L. (NS) has received much research attention as an antioxidant, anti-yperglycemic factor, and anti-inflammatory agent. This natural compound demonstrates its antidiabetic neuropathy effect through various pathways, including the reduction of lipid peroxidation, the enhancement of catalase and superoxide dismutase enzyme activity, and the decrease in inflammatory cytokine levels. The present review focuses on the bioactive and nutraceutical components of black cumin (Nigella sativa L.) and their effects on DPN. In addition, we have also summarized the findings obtained from several experimental and clinical studies regarding the antidiabetic neuropathy effect of NS in animal models and human subjects.

Phytoconstituents as modulators of NF-κB signalling: Investigating therapeutic potential for diabetic wound healing

The NF-κB pathway plays a pivotal role in impeding the diabetic wound healing process, contributing to prolonged inflammation, diminished angiogenesis, and reduced proliferation. In contrast to modern synthetic therapies, naturally occurring phytoconstituents are well-studied inhibitors of the NF-κB pathway that are now attracting increased attention in the context of diabetic wound healing because of lower toxicity, better safety and efficacy, and cost-effectiveness. This study explores recent research on phytoconstituent-based therapies and delve into their action mechanisms targeting the NF-κB pathway and potential for assisting effective healing of diabetic wounds. For this purpose, we have carried out surveys of recent literature and analyzed studies from prominent databases such as Science Direct, Scopus, PubMed, Google Scholar, EMBASE, and Web of Science. The classification of phytoconstituents into various categorie such as: alkaloids, triterpenoids, phenolics, polyphenols, flavonoids, monoterpene glycosides, naphthoquinones and tocopherols. Noteworthy phytoconstituents, including Neferine, Plumbagin, Boswellic acid, Genistein, Luteolin, Kirenol, Rutin, Vicenin-2, Gamma-tocopherol, Icariin, Resveratrol, Mangiferin, Betulinic acid, Berberine, Syringic acid, Gallocatechin, Curcumin, Loureirin-A, Loureirin-B, Lupeol, Paeoniflorin, and Puerarin emerge from these studies as promising agents for diabetic wound healing through the inhibition of the NF-κB pathway. Extensive research on various phytoconstituents has revealed how they modulate signalling pathways, including NF-κB, studies that demonstrate the potential for development of therapeutic phytoconstituents to assist healing of chronic diabetic wounds.

AMPK pathway: an emerging target to control diabetes mellitus and its related complications

Purpose

In this extensive review work, the important role of AMP-activated protein kinase (AMPK) in causing of diabetes mellitus has been highlighted. Structural feature of AMPK as well its regulations and roles are described nicely, and the association of AMPK with the diabetic complications like nephropathy, neuropathy and retinopathy are also explained along with the connection between AMPK and β-cell function, insulin resistivity, mTOR, protein metabolism, autophagy and mitophagy and effect on protein and lipid metabolism.

Methods

Published journals were searched on the database like PubMed, Medline, Scopus and Web of Science by using keywords such as AMPK, diabetes mellitus, regulation of AMPK, complications of diabetes mellitus, autophagy, apoptosis etc.

Result

After extensive review, it has been found that, kinase enzyme like AMPK is having vital role in management of type II diabetes mellitus. AMPK involve in enhance the concentration of glucose transporter like GLUT 1 and GLUT 4 which result in lowering of blood glucose level in influx of blood glucose into the cells; AMPK increases the insulin sensitivity and decreases the insulin resistance and further AMPK decreases the apoptosis of β-cells which result into secretion of insulin and AMPK is also involve in declining of oxidative stress, lipotoxicity and inflammation, owing to which organ damage due to diabetes mellitus can be lowered by activation of AMPK.

Conclusion

As AMPK activation leads to overall control of diabetes mellitus, designing and developing of small molecules or peptide that can act as AMPK agonist will be highly beneficial for control or manage diabetes mellitus.

Emerging Perspectives on the Impact of Diabetes Mellitus and Anti-Diabetic Drugs on Premenstrual Syndrome. A Narrative Review

Diabetes mellitus (DM) and premenstrual syndrome (PMS) are global health challenges. Both disorders are often linked to a range of physical and psychological symptoms that significantly impact the quality of life of many women. Yet, the exact relation between DM and PMS is not clear, and the management of both conditions poses a considerable challenge. In this review, we aimed to investigate the interplay between DM, anti-diabetic drugs, and the different theories and symptoms of PMS. Female sex hormones are implicated in the pathophysiology of PMS and can also impair blood glucose control. In addition, patients with diabetes face a higher susceptibility to anxiety and depression disorders, with a significant number of patients experiencing symptoms such as fatigue and difficulty concentrating, which are reported in patients with PMS as well. Complications related to diabetic medications, such as hypoglycemia (with sulfonylurea) and fluid retention (with thiazolidinediones) may also mediate PMS-like symptoms. DM can, in addition, disturb the normal gut microbiota (GM), with a consequent loss of beneficial GM metabolites that guard against PMS, particularly the short-chain fatty acids and serotonin. Among the several available anti-diabetic drugs, those (1) with an anti-inflammatory potential, (2) that can preserve the beneficial GM, and (3) possessing a lower risk for hypoglycemia, might have a favorable outcome in PMS women. Yet, well-designed clinical trials are needed to investigate the anti-diabetic drug(s) of choice for patients with diabetes and PMS.

Mitochondrial regulation of diabetic endothelial dysfunction: Pathophysiological links

Micro- and macrovascular complications frequently occur in patients with diabetes, with endothelial dysfunction playing a key role in the development and progression of the complications. For the early diagnosis and optimal treatment of vascular complications associated with diabetes, it is imperative to comprehend the cellular and molecular mechanisms governing the function of diabetic endothelial cells. Mitochondria function as crucial sensors of environmental and cellular stress regulating endothelial cell viability, structural integrity and function. Impaired mitochondrial quality control mechanisms and mitochondrial dysfunction are the main features of endothelial damage. Hence, targeted mitochondrial therapy is considered promising novel therapeutic options in vascular complications of diabetes. In this review, we focus on the mitochondrial functions in the vascular endothelial cells and the pathophysiological role of mitochondria in diabetic endothelial dysfunction, aiming to provide a reference for related drug development and clinical diagnosis and treatment.

Comparison of therapeutic effects of N-Acetylcysteine with pregabalin in improving the clinical symptoms of painful diabetic neuropathy: a randomized, double-blind clinical trial

OBJECTIVES

Painful diabetic neuropathy (PDN) is highly prevalent and annoyingly in patients with diabetes. The aim of this study was to investigate the effects of oral N-acetylcysteine (NAC) compared to pregabalin in PDN.

METHODS

One hundred two eligible patients with type 2 diabetes and PDN were randomly recievied pregabalin (150 mg/day) or N-Acetylcysteine (NAC) (600 mg/ twice a day) for 8 weeks. Mean pain score, Sleep interference score (SIS), Patient Global Impression of Change (PGIC), Clinical Global Impression of Change (CGIC), and also, serum levels of total antioxidant capacity (TAC), total thiol groups (TTG), catalase activity (CAT), nitric oxide (NO), and malondialdehyde (MDA) were assessed at baseline and at the end of the study.

RESULTS

NAC was well tolerated in all patients. The decrease in mean pain scores and increase in SIS was similar between two groups. More improvement in PGIC and CGIC from the baseline was reported in NAC group. NAC, significantly, decreased serum levels of MDA, and NO, but increased TAC, TTG, and CAT. Pregabalin, significantly, decreased serum levels of MDA, and NO and increased TAC.

DISCUSSION

NAC is efficacious in alleviate symptoms of PDN which is probably related to its antioxidant effects.

TRIAL REGISTRATION

The research protocol received approval from the Ethics Committee of Hamadan University of Medical Sciences (IR.UMSHA.REC.1397.137). The trial registry URL and number in Iranian Registry of Clinical Trials (IRCT): https://www.irct.ir/trial/33313 , IRCT20180814040795N2 (Registration date: 2019-01-21, Retrospectively registered).

ROS signaling in innate immunity via oxidative protein modifications

The innate immune response represents the first-line of defense against invading pathogens. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been implicated in various aspects of innate immune function, which involves respiratory bursts and inflammasome activation. These reactive species widely distributed within the cellular environment are short-lived intermediates that play a vital role in cellular signaling and proliferation and are likely to depend on their subcellular site of formation. NADPH oxidase complex of phagocytes is known to generate superoxide anion radical (O2 •-) that functions as a precursor for antimicrobial hydrogen peroxide (H2O2) production, and H2O2 is utilized by myeloperoxidase (MPO) to generate hypochlorous acid (HOCl) that mediates pathogen killing. H2O2 modulates the expression of redox-responsive transcriptional factors, namely NF-kB, NRF2, and HIF-1, thereby mediating redox-based epigenetic modification. Survival and function of immune cells are under redox control and depend on intracellular and extracellular levels of ROS/RNS. The current review focuses on redox factors involved in the activation of immune response and the role of ROS in oxidative modification of proteins in macrophage polarization and neutrophil function.

Mechanism of traditional Chinese medicine in elderly diabetes mellitus and a systematic review of its clinical application

Objective: Affected by aging, the elderly diabetes patients have many pathological characteristics different from the young people, including more complications, vascular aging, cognitive impairment, osteoporosis, and sarcopenia. This article will explore their pathogenesis and the mechanism of Traditional Chinese medicine (TCM) intervention, and use the method of systematic review to evaluate the clinical application of TCM in elderly diabetes. Method: Searching for randomized controlled trials (RCTs) published from January 2000 to November 2023 in the following databases: Web of Science, Pubmed, Embase, Cochrane Library, Sinomed, China National Knowledge Internet, Wanfang and VIP. They were evaluated by three subgroups of Traditional Chinese Prescription, Traditional Chinese patent medicines and Traditional Chinese medicine extracts for their common prescriptions, drugs, adverse reactions and the quality of them. Results and Conclusion: TCM has the advantages of multi-target and synergistic treatment in the treatment of elderly diabetes. However, current clinical researches have shortcomings including the inclusion of age criteria and diagnosis of subjects are unclear, imprecise research design, non-standard intervention measures, and its safety needs further exploration. In the future, the diagnosis of elderly people with diabetes needs to be further clarified. Traditional Chinese patent medicines included in the pharmacopoeia can be used to conduct more rigorous RCTs, and then gradually standardize the traditional Chinese medicine prescriptions and traditional Chinese medicine extracts, providing higher level evidence for the treatment of elderly diabetes with traditional Chinese medicine.

Phthalocyanine-based glucose-responsive nanocochleates for dynamic prevention of β-cell damage in diabetes

Phthalocyanine is a blue-colored macrocyclic compound with excellent anti-oxidant and lipid-peroxidation abilities due to its intermolecular π-π stacking structure. Antioxidants inhibit intracellular reactive oxygen species formation and decrease oxidation defense ability of the enzymes in diabetes management. The present study aimed to fabricate concanavalin A conjugated phthalocyanine-loaded cochleates (Formulation PhConA) as a glucose-sensitive lipidic system and estimate its efficacy in streptozotocin-induced male Sprague Dawley diabetic rats for 28 days. Thin-film hydration and trapping methods were used in the preparation of liposomes and cochleates, respectively, whereas the surface was modified for concanavalin A conjugation using EDAC: NHS (1:1). Formulation PhConA with rod-shaped structures showed particle size of 415.7 ± 0.46 nm, PdI value of 0.435 ± 0.09, encapsulation efficiency of 85.64 ± 0.34%, and 84.55 ± 0.29% release of phthalocyanine for 56 h. The circular dichroism study displayed a slight deviation after the conjugation effect of concanavalin A to cochleates. The in-vivo studies of the formulation PhConA improved the blood glucose levels along with defensive effect on the liver to overcome the hyperlipidemic effect. The rigid structure of cochleates prolongs the drug elimination from systemic circulation and extends its effect for a longer duration by decreasing the blood glucose level. Thus, the glucose-sensitive formulation PhConA showed significant improvement in diabetic rats within the period of 28 days by improving the oxidative defense and protecting the pancreatic β-cells.

Elucidation of the anti-β-cell dedifferentiation mechanism of a modified Da Chaihu Decoction by an integrative approach of network pharmacology and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Da Chaihu decoction (MDCH) is a traditional Chinese herbal prescription that has been used in the clinic to treat type 2 diabetes (T2D). Previous studies have confirmed that MDCH improves glycemic and lipid metabolism, enhances pancreatic function, and alleviates insulin resistance in patients with T2D and diabetic rats. Evidence has demonstrated that MDCH protects pancreatic β cells via regulating the gene expression of sirtuin 1 (SIRT1) and forkhead box protein O1 (FOXO1). However, the detailed mechanism remains unclear.

AIM OF THE STUDY

Dedifferentiation of pancreatic β cells mediated by FOXO1 has been recognized as the main pathogenesis of T2D. This study aims to investigate the therapeutic effects of MDCH on T2D in vitro and in vivo to elucidate the potential molecular mechanisms.

MATERIALS AND METHODS

To predict the key targets of MDCH in treating T2D, network pharmacology methods were used. A T2D model was induced in diet-induced obese (DIO) C57BL/6 mice with a single intraperitoneal injection of streptozotocin. Glucose metabolism indicators (oral glucose tolerance test, insulin tolerance test), lipid metabolism indicators (total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol), inflammatory factors (C-reactive protein, interleukin 6, tumor necrosis factor alpha), oxidative stress indicators (total antioxidant capacity, superoxide dismutase, malondialdehyde), and hematoxylin and eosin staining were analyzed to evaluate the therapeutic effect of MDCH on T2D. Immunofluorescence staining and quantification of FOXO1, pancreatic and duodenal homeobox 1 (PDX1), NK6 homeobox 1 (NKX6.1), octamer-binding protein 4 (OCT4), neurogenin 3 (Ngn3), insulin, and SIRT1, and Western blot analysis of insulin, SIRT1, and FOXO1 were performed to investigate the mechanism by which MDCH inhibited pancreatic β-cell dedifferentiation.

RESULTS

The chemical ingredients identified in MDCH were predicted to be important for signaling pathways related to lipid metabolism and insulin resistance, including lipids in atherosclerosis, the advanced glycation end product receptor of the advanced glycation end product signaling pathway, and the FOXO signaling pathway. Experimental studies showed that MDCH improved glucose and lipid metabolism in T2D mice, alleviated inflammation and oxidative stress damage, and reduced pancreatic pathological damage. Furthermore, MDCH upregulated the expression levels of SIRT1, FOXO1, PDX1, and NKX6.1, while downregulating the expression levels of OCT4 and Ngn3, which indicated that MDCH inhibited pancreatic dedifferentiation of β cells.

CONCLUSIONS

MDCH has therapeutic effects on T2D, through regulating the SIRT1/FOXO1 signaling pathway to inhibit pancreatic β-cell dedifferentiation, which has not been reported previously.

Structural perturbations induced by cumulative action of methylglyoxal and peroxynitrite on human fibrinogen: An in vitro and in silico approach

Methylglyoxal (MGO); a reducing sugar and a dicarbonyl; attaches to the biomolecules (proteins, lipids, and DNA) leading to glycation and accumulation of oxidative stress in cells and tissues. Superoxide anion formed under such conditions entraps free nitric oxide radical (NO) to form peroxynitrite (PON). Nitro-oxidative stress due to PON is well established. Human fibrinogen plays a key role in haemostasis and is a highly vulnerable target for oxidation. Modifications of fibrinogen can potentially disrupt its structure and function. Earlier evidence suggested that glycation and nitro-oxidation lead to protein aggregation by making it resistant to lysis. This study aims to reveal the structural perturbations on fibrinogen in the presence of MGO and PON synergistically. The in vitro glyco-nitro-oxidation of human fibrinogen by MGO and PON leads to substantial structural alterations, as evident by biophysical and biochemical studies. In-silico results revealed the formation of stable complexes. UV-visible, intrinsic fluorescence, and circular dichroism investigations confirmed the synergistic effect of MGO and PON caused micro-structural modifications leading to secondary structural alterations. AGEs formation in MGO-modified fibrinogen reduced the free lysine and free arginine residues which were quantified by TNBS and phenanthrenequinone assays. Enhanced oxidative status was confirmed by estimating carbonyl content. ANS fluorophore validated exposure of hydrophobic patches in modified protein and thioflavin-T showed maximum binding with synergistically modified fibrinogen, indicated the formation of β-sheet. Confocal and electron microscope results corroborated the formation of aggregates. This study, therefore, evaluated the impact of MGO and PON on the structural integrity, oxidative status and aggregate formation of fibrinogen that can aggravate metabolic complications.

Green Synthesis of Novel Silver Nanoparticles Using Salvia blepharophylla and Salvia greggii: Antioxidant and Antidiabetic Potential and Effect on Foodborne Bacterial Pathogens

In the face of evolving healthcare challenges, the utilization of silver nanoparticles (AgNPs) has emerged as a compelling solution due to their unique properties and versatile applications. The aim of this study was the synthesis and characterization of novel AgNPs (SB-AgNPs and SG-AgNPs, respectively) using Salvia blepharophylla and Salvia greggii leaf extracts and the evaluation of their antimicrobial, antioxidant, and antidiabetic activities. Several analytical instrumental techniques were utilized for the characterization of SB-AgNPs and SG-AgNPs, including UV-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transmission infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). FTIR analysis identified various functional groups in the leaf extracts and nanoparticles, suggesting the involvement of phytochemicals as reducing and stabilizing agents. High-resolution TEM images displayed predominantly spherical nanoparticles with average sizes of 52.4 nm for SB-AgNPs and 62.5 nm for SG-AgNPs. Both SB-AgNPs and SG-AgNPs demonstrated remarkable antimicrobial activity against Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and Gram-negative bacteria Salmonella typhimurium and Escherichia coli. SB-AgNPs and SG-AgNPs also exhibited 90.2 ± 1.34% and 89.5 ± 1.5% DPPH scavenging and 86.5 ± 1.7% and 80.5 ± 1.2% α-amylase inhibition, respectively, at a concentration of 100 μg mL-1. Overall, AgNPs synthesized using S. blepharophylla and Salvia greggii leaf extracts may serve as potential candidates for antibacterial, antioxidant, and antidiabetic agents. Consequently, this study provides viable solutions to mitigate the current crisis of antibiotic resistance and to efficiently combat antimicrobial infections and Type 2 diabetes.

Is inverse association between lipoprotein(a) and diabetes mellitus another paradox in cardiometabolic medicine?

INTRODUCTION

The impact of Type II Diabetes mellitus (T2DM) on cardiovascular disease (CVD) is well-established, while lipoprotein(a) [Lp(a)] has recently emerged as a recognized CVD risk factor. The rising prevalence of T2DM resulting from modern lifestyles and the development of specific Lp(a)-lowering agents brought the association between T2DM and Lp(a) in the forefront.

AREAS COVERED

Despite advancements in T2DM treatment, diabetic patients remain at very-high risk of CVD. Lp(a) may, to some extent, contribute to the persistent CVD risk seen in diabetic patients, and the coexistence of T2DM and elevated Lp(a) levels appears to synergistically amplify overall CVD risk. The relationship between T2DM and Lp(a) is paradoxical. On one hand, high Lp(a) plasma concentrations elevate the risk of diabetic microvascular and macrovascular complications. On the other hand, low Lp(a) plasma concentrations have been linked to an increased risk of developing T2DM.

EXPERT OPINION

Comprehending the association between T2DM and Lp(a) is critical due to the pivotal roles both entities play in overall CVD risk, as well as the unique aspects of their relationship. The mechanisms underlying the inverse association between T2DM and Lp(a) remain incompletely understood, necessitating further meticulous research.

A machine learning prediction model for cancer risk in patients with type 2 diabetes based on clinical tests

BACKGROUND

The incidence of type 2 diabetes is rapidly increasing worldwide. Studies have shown that it is also associated with cancer-related morbidities. Early detection of cancer in patients with type 2 diabetes is crucial.

OBJECTIVE

This study aimed to construct a model to predict cancer risk in patients with type 2 diabetes.

METHODS

This study collected clinical data from a total of 5198 patients. A cancer risk prediction model was established by analyzing 261 items from routine laboratory tests. We screened 107 risk factors from 261 clinical tests based on the importance of the characteristic variables, significance of differences between groups (P< 0.05), and minimum description length algorithm.

RESULTS

Compared with 16 machine learning classifiers, five classifiers based on the decision tree algorithm (CatBoost, light gradient boosting, random forest, XGBoost, and gradient boosting) had an area under the receiver operating characteristic curve (AUC) of > 0.80. The AUC for CatBoost was 0.852 (sensitivity: 79.6%; specificity: 83.2%).

CONCLUSION

The constructed model can predict the risk of cancer in patients with type 2 diabetes based on tumor biomarkers and routine tests using machine learning algorithms. This is helpful for early cancer risk screening and prevention to improve patient outcomes.

Decrypting the circular RNAs does a favor for us: Understanding, diagnosing and treating diabetes mellitus and its complications

Circular RNAs (circRNAs), a novel type of single-stranded noncoding RNAs with a covalently closed loop structure, are generated in a circular conformation via non-canonical splicing or back-splicing events. Functionally, circRNAs have been elucidated to soak up microRNAs (miRNAs) and RNA binding proteins (RBPs), serve as protein scaffolds, maintain mRNA stability, and regulate gene transcription and translation. Notably, circRNAs are strongly implicated in the regulation of β-cell functions, insulin resistance, adipocyte functions, inflammation as well as oxidative stress via acting as miRNA sponges and RBP sponges. Basic and clinical studies have demonstrated that aberrant alterations of circRNAs expressions are strongly associated with the initiation and progression of diabetes mellitus (DM) and its complications. Here in this review, we present a summary of the biogenesis, transportation, degradation and functions of circRNAs, and highlight the recent findings on circRNAs and their action mechanisms in DM and its complications. Overall, this review should contribute greatly to our understanding of circRNAs in DM pathogenesis, offering insights into the further perspectives of circRNAs for DM diagnosis and therapy.

Loxenatide attenuates ROS-mediated vascular endothelial progenitor cell damage and mitochondrial dysfunction via SIRT3/Foxo3 signaling pathway

Diabetes mellitus (DM), becomes a main public health issue worldwide due to the rapid increase in DM patient numbers. The dysfunction of endothelial progenitor cells (EPCs) in DM patients plays a critical role in endothelial repair and the progression of DM-related vascular complications. Loxenatide is an a glucagon-like peptide 1 receptor agonist, which is used to control glycemic in type 2 diabetes patients. However, the role of Loxenatide in EPCs remains to be investigated. EPCs were isolated, characterized, and treated with Loxenatide, high-glucose, or 3-TYP. quantitative real-time polymerase chain reaction, flow cytometry, western blot, and cell counting kit-8 assay were employed to validate the expression of gene and protein expressions and cell viability, respectively. Application of Seahorse XFp to measure oxygen consumption and mitochondrial membrane potential (MMP) were measured by Seahorse XFp and MMP assay. Loxenatide attenuated high-glucose-induced reactive oxygen species (ROS) production and mitochondrial-dependent apoptosis of EPCs in a concentration-dependent manner. The EPC mitochondrial respiration dysfunction induced by high glucose was also repressed by the loxenatide treatment. The protection effect of Loxenatide on EPCs against high-glucose was applied by activating the sirtuin 3 (SIRT3)/Foxo3 signaling pathway. We demonstrated the regulatory role of Loxenatide in mitochondrial dysfunction and apoptosis of EPCs. We elucidated that Loxenatide protects EPC from high-glucose-induced apoptosis via ROS-mediated mitochondrial pathway through the SIRT3/Foxo3 signing pathway. This may provide a new therapeutical target for the treatment of DM-related vascular complications.

α-lipoic acid ameliorates hepatotoxicity induced by chronic ammonia toxicity in crucian carp (Carassius auratus gibelio) by alleviating oxidative stress, inflammation and inhibiting ERS pathway

High environment ammonia (HEA) poses a deadly threat to aquatic animals and indirectly impacts human healthy life, while nutritional regulation can alleviate chronic ammonia toxicity. α-lipoic acid exhibits antioxidative effects in both aqueous and lipid environments, mitigating cellular and tissue damage caused by oxidative stress by aiding in the neutralization of free radicals (reactive oxygen species). Hence, investigating its potential as an effective antioxidant and its protective mechanisms against chronic ammonia stress in crucian carp is highly valuable. Experimental fish (initial weight 20.47 ± 1.68 g) were fed diets supplemented with or without 0.1% α-lipoic acid followed by a chronic ammonia exposure (10 mg/L) for 42 days. The results revealed that chronic ammonia stress affected growth (weight gain rate, specific growth rate, and feed conversion rate), leading to oxidative stress (decreased the activities of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase; decreased total antioxidant capacity), increased lipid peroxidation (accumulation of malondialdehyde), immune suppression (decreased contents of nonspecific immune enzymes AKP and ACP, 50% hemolytic complement, and decrease of immunoglobulin M), impaired ammonia metabolism (reduced contents of Glu, GS, GSH, and Gln), imbalance of expression of induced antioxidant-related genes (downregulation of Cu/Zu SOD, CAT, Nrf2, and HO-1; upregulation of GST and Keap1), induction of pro-apoptotic molecules (transcription of BAX, Caspase3, and Caspase9), downregulation of anti-apoptotic gene Bcl-2 expression, and induction of endoplasmic reticulum stress (upregulation of IRE1, PERK, and ATF6 expression). The results suggested that the supplementation of α-lipoic acid could effectively induce humoral immunity, alleviate oxidative stress injury and endoplasmic reticulum stress, and ultimately alleviate liver injury induced by ammonia poisoning (50-60% reduction). This provides theoretical basis for revealing the toxicity of long-term ammonia stress and provides new insights into the anti-ammonia toxicity mechanism of α-lipoic acid.

Potential Benefits of Antioxidant Phytochemicals in Type 2 Diabetes

The clinical relationship between diabetes and inflammation is well established. Evidence clearly indicates that disrupting oxidant-antioxidant equilibrium and elevated lipid peroxidation could be a potential mechanism for chronic kidney disease associated with type 2 diabetes mellitus (T2DM). Under diabetic conditions, hyperglycemia, especially inflammation, and increased reactive oxygen species generation are bidirectionally associated. Inflammation, oxidative stress, and tissue damage are believed to play a role in the development of diabetes. Although the exact mechanism underlying oxidative stress and its impact on diabetes progression remains uncertain, the hyperglycemia-inflammation-oxidative stress interaction clearly plays a significant role in the onset and progression of vascular disease, kidney disease, hepatic injury, and pancreas damage and, therefore, holds promise as a therapeutic target. Evidence strongly indicates that the use of multiple antidiabetic medications fails to achieve the normal range for glycated hemoglobin targets, signifying treatment-resistant diabetes. Antioxidants with polyphenols are considered useful as adjuvant therapy for their potential anti-inflammatory effect and antioxidant activity. We aimed to analyze the current major points reported in preclinical, in vivo, and clinical studies of antioxidants in the prevention or treatment of inflammation in T2DM. Then, we will share our speculative vision for future diabetes clinical trials.

Regulatory mechanisms underlying endoplasmic reticulum stress involvement in the development of gestational diabetes mellitus entail the CHOP-PPARα-NF-κB pathway

OBJECTIVE

We investigated the proinflammatory functions of endoplasmic reticulum stress and peroxisome proliferator-activated receptor α (PPARα) in the development of gestational diabetes mellitus (GDM) and their relationship in regulating inflammation in GDM.

METHODS

This study was performed on placentas of normal pregnant women, women with GDM, and HTR8 cells. Transmission electron microscopy, immunohistochemistry, Western blot analysis, and RT-PCR were performed to analyze ERS and PPARα expression on both normal and GDM pregnancy placentas. ELISA was performed to analyze inflammatory biomarkers. To generate models of the GDM-like state, placentas of normal pregnancy were treated with LPS and polyinosinic-polycytidylic acid (poly [I:C]). TG, CHOP plasmid, and CHOP siRNA were assessed as to their regulation of HTR8 cells to discern the relationship between ERS and PPARα in regulating the inflammation associated with GDM.

RESULTS

ERS was elevated in GDM placentas, induced the secretion of IL-6 and TNF-α, and attenuated the expression of GLUT-4. PPARα was diminished in GDM placentas and inhibited the inflammatory responses via the NF-κB nuclear-transport process. 4-PBA reduced CHOP and augmented PPARα, and it decreased IL-6 and TNF-α in our GDM-like explant. However, with both 4-PBA and MK886 treatment, we noted no significant difference in CHOP expression. The level of PPARα was reduced, and that of NF-κB p65 in the nucleus was elevated with TG treatment in the HTR8/Svneo. Knockdown of CHOP increased PPARα and reduced NF-κB p65, while expression of PPARα declined, and that of NF-κB p65 rose with the application of CHOP when HTR8 cells were treated with TG.

CONCLUSIONS

ERS contributes to the pathophysiology of GDM in pregnancy via the CHOP-PPARα-NF-κB-signalling pathway by inducing aberrant activation of inflammation and insulin resistance.

Advanced glycation end products: Key mediator and therapeutic target of cardiovascular complications in diabetes

The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns. Cardiovascular complications associated with diabetes are the leading cause of morbidity and mortality. The cardiovascular diseases that accompany diabetes include angina, myocardial infarction, stroke, peripheral artery disease, and congestive heart failure. Among the various risk factors generated secondary to hyperglycemic situations, advanced glycation end products (AGEs) are one of the important targets for future diagnosis and prevention of diabetes. In the last decade, AGEs have drawn a lot of attention due to their involvement in diabetic patho-physiology. AGEs can be derived exogenously and endogenously through various pathways. These are a non-homogeneous, chemically diverse group of compounds formed non-enzymatically by condensation between carbonyl groups of reducing sugars and free amino groups of protein, lipids, and nucleic acid. AGEs mediate their pathological effects at the cellular and extracellular levels by multiple pathways. At the cellular level, they activate signaling cascades via the receptor for AGEs and initiate a complex series of intracellular signaling resulting in reactive oxygen species generation, inflammation, cellular proliferation, and fibrosis that may possibly exacerbate the damaging effects on cardiac functions in diabetics. AGEs also cause covalent modifications and cross-linking of serum and extracellular matrix proteins; altering their structure, stability, and functions. Early diagnosis of diabetes may prevent its progression to complications and decrease its associated comorbidities. In the present review, we recapitulate the role of AGEs as a crucial mediator of hyperglycemia-mediated detrimental effects in diabetes-associated complications. Furthermore, this review presents an overview of future perspectives for new therapeutic interventions to ameliorate cardiovascular complications in diabetes.

Chemical exposure and alveolar macrophages responses: 'the role of pulmonary defense mechanism in inhalation injuries'

Epidemiological and clinical studies have indicated an association between particulate matter (PM) exposure and acute and chronic pulmonary inflammation, which may be registered as increased mortality and morbidity. Despite the increasing evidence, the pathophysiology mechanism of these PMs is still not fully characterised. Pulmonary alveolar macrophages (PAMs), as a predominant cell in the lung, play a critically important role in these pathological mechanisms. Toxin exposure triggers events associated with macrophage activation, including oxidative stress, acute damage, tissue disruption, remodelling and fibrosis. Targeting macrophage may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections. Biological toxins, their sources of exposure, physical and other properties, and their effects on the individuals are summarised in this article. Inhaled particulates from air pollution and toxic gases containing chemicals can interact with alveolar epithelial cells and immune cells in the airways. PAMs can sense ambient pollutants and be stimulated, triggering cellular signalling pathways. These cells are highly adaptable and can change their function and phenotype in response to inhaled agents. PAMs also have the ability to polarise and undergo plasticity in response to tissue damage, while maintaining resistance to exposure to inhaled agents.

Evaluation of Cerebral Vasomotor Reactivity by Transcranial Doppler Ultrasound in Patients with Diabetic Retinopathy

The aim of this study was to assess the correlation between cerebral vasomotor reactivity (CVR) and the grade of diabetic retinopathy. A total of 43 diabetic patients with matched severity of diabetic retinopathy between their right and left eyes were included in this study. Diabetic retinopathy was graded in three groups. Right and left middle cerebral artery CVR was assessed by the breath-holding index (BHI) using transcranial Doppler ultrasound (TCD). The mean age of the patients was 56.51 ± 9.34 years with a mean duration of having diabetes mellitus of 14.49 ± 8.06 years. Diabetic retinopathy was graded as mild, moderately severe, and severe in 27.9%, 34.9%, and 37.2% of the patients, respectively. The grade of diabetic retinopathy was associated with the HbA1c level (p < .049), microalbuminuria (p < .024), and BHI (p = .001). In patients with severe diabetic retinopathy, the right-sided BHI was significantly lower as compared to those with mild or moderately severe retinopathy (p = .001 and p = .008, respectively). The left-sided BHI value in patients with severe diabetic retinopathy was significantly lower as compared to those with mild or moderately severe retinopathy (p = .001 and p = .012, respectively). In subjects with moderately severe diabetic retinopathy, both-sided BHI was significantly reduced compared to those with mild retinopathy (p = .001). Our results indicate that the grade of diabetic retinopathy was associated with impaired CVR.

Characterization of Serrulatane Diterpenoids in Eremophila phyllopoda subsp. phyllopoda by Triple High-Resolution α-Glucosidase/PTP1B/Radical Scavenging Profiling, NMR Spectroscopy, DFT-GIAO NMR, and Electronic Circular Dichroism Calculations

Extracts of Eremophila phyllopoda subsp. phyllopoda showed α-glucosidase and PTP1B inhibitory activity with IC50 values of 19.6 and 13.6 μg/mL, respectively. High-resolution α-glucosidase/PTP1B/radical scavenging profiling was performed to establish a triple high-resolution inhibition profile that allowed direct pinpointing of the constituents responsible for one or more of the observed bioactivities. Subsequent targeted isolation and purification by analytical-scale HPLC led to the identification of 21 previously undescribed serrulatane diterpenoids, eremophyllanes A-U, as well as two known serrulatane diterpenoids, 1β-trihydroxyserrulatane (8) and 1α-trihydroxyserrulatane (10d), and five known furofuran lignans, (+)-piperitol (6), horsfieldin (7e), (-)-sesamin (9), (+)-sesamin (10h), and asarinin (10i). Their structures were elucidated by extensive analysis of HRMS and 1D and 2D NMR spectroscopic data. The relative configurations of the previously undescribed compounds were established by analysis of ROESY spectra as well as by DFT-GIAO NMR calculations followed by DP4+ probability analysis. The absolute configurations were determined by comparison of experimental and calculated ECD spectra. Serrulatane diterpenoids 7b and 14 exhibited α-glucosidase inhibitory activity with IC50 values of 28.4 and 64.2 μM, respectively, while 11, 12, 14, and 15 exhibited PTP1B inhibitory activity with IC50 values ranging from 16.6 to 104.6 μM. Hypothetical routes for formation of all identified serrulatane diterpenoids are proposed.

Single Nucleotide Polymorphisms of the RAC1 Gene as Novel Susceptibility Markers for Neuropathy and Microvascular Complications in Type 2 Diabetes

Single nucleotide polymorphisms (SNP) in the RAC1 (Rac family small GTPase 1) gene have recently been linked to type 2 diabetes (T2D) and hyperglycemia due to their contribution to impaired redox homeostasis. The present study was designed to determine whether the common SNPs of the RAC1 gene are associated with diabetic complications such as neuropathy (DN), retinopathy (DR), nephropathy, angiopathy of the lower extremities (DA), and diabetic foot syndrome. A total of 1470 DNA samples from T2D patients were genotyped for six common SNPs by the MassArray Analyzer-4 system. The genotype rs7784465-T/C of RAC1 was associated with an increased risk of DR (p = 0.016) and DA (p = 0.03) in males, as well as with DR in females (p = 0.01). Furthermore, the SNP rs836478 showed an association with DR (p = 0.005) and DN (p = 0.025) in males, whereas the SNP rs10238136 was associated with DA in females (p = 0.002). In total, three RAC1 haplotypes showed significant associations (FDR < 0.05) with T2D complications in a sex-specific manner. The study's findings demonstrate, for the first time, that the RAC1 gene's polymorphisms represent novel and sex-specific markers of neuropathy and microvascular complications in type 2 diabetes, and that the gene could be a new target for the pharmacological inhibition of oxidative stress as a means of preventing diabetic complications.

Visnagin Attenuates Gestational Diabetes Mellitus in Streptozotocin-induced Diabetic Pregnant Rats via Regulating Dyslipidemia, Oxidative Stress, and Inflammatory Response

Background:

Gestational diabetes mellitus (GDM) is a condition of glucose intolerance and insulin resistance only diagnosed during pregnancy. GDM has exhibited several adverse effects on both mother and offspring. The current research focuses on discovering visnagin’s beneficial properties against the streptozotocin (STZ)-induced GDM in rats via alleviating the inflammation and oxidative stress.

Materials and Methods:

GDM was caused in the pregnant rats by the administration of 25 mg/kg of STZ by the intraperitoneal route and then treated with 20 mg/kg of visnagin for 20 consecutive days. The rats’ body weight was measured, and fasting blood glucose (FBG) status was determined using a standard glucometer. The contents of total cholesterol (TCh), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were assessed using kits. The MDA level, total antioxidant capacity (TAC) status, and activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were determined using assay kits. Kits also assessed the contents of TNF-α and IL-1β. The contents of TNF-α and IL-1β effectively improved the body weight and decreased the FBG status in the GDM rats. The visnagin also decreased the TCh, TG, and LDL, and elevated the HDL content. The content of MDA was decreased and the visnagin treatment increased SOD, CAT, GST, and GPx, and the visnagin treatment increased SOD, CAT, GST, and GPx activities SOD, CAT, GST, and GPx activities. The visnagin effectively decreased the STZ-induced histopathological alterations in the pancreas.

Conclusion:

Altogether, our investigation results suggest a beneficial role visnagin against STZ-induced GDM in rats via inhibiting the inflammatory responses. Hence, it can be a talented therapeutic candidate for the successful management of GDM.

Senna petersiana (Bolle) leaf extract modulates glycemic homeostasis and improves dysregulated enzyme activities in fructose-fed streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Senna petersiana (Bolle) is a native South African medicinal shrub combined locally with other plant products to manage diabetes or used as a single therapy for several other ailing conditions.

AIM OF THE STUDY

This study evaluated the antidiabetic and antilipidemic effects of S. petersiana leaf ethanol extract and its modulatory effects on dysregulated enzyme activities in fructose-fed streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Six groups of 6-weeks old male Sprague Dawley rats were used in this study. Diabetes was induced in four of the groups by injecting (i.p.) 40 mg/kg of streptozotocin after a two-weeks feeding of 10% fructose via drinking water, while animals in the two normal groups were given similar volume of vehicle buffer and normal drinking water, respectively. After the confirmation of diabetes, treatment with 150 and 300 mg/kg body weight of the ethanolic leaf extract of S. petersiana proceeded for a period of 6 weeks.

RESULTS

Oral administration of S. petersiana leaf extract significantly lowered blood glucose, food and liquid intake, glycosylhaemoglobin in blood, liver and cardiac biomarkers, and lipid profile in serum and atherogenic index (AIP) in both the low and high-dose treated animal groups. This was accompanied by a simultaneous increase in Homeostatic Model Assessment-beta (HOMA-β) score, serum high-density lipoproteins cholesterol (HDL-c), and insulin levels. It also improved pancreatic and serum-reduced glutathione (GSH) levels, catalase, and superoxide dismutase (SOD) enzymes activities with a simultaneous reduction in malondialdehyde (MDA) and nitric oxide (NO) concentrations. Moreover, the extract modulated dysregulated α-amylase, lipase, cholinesterase, and 5' nucleotidase enzyme activities in pancreatic tissue as well as glycogen metabolism in the liver. Analysis of the phytochemicals in the S. petersiana extract showed the presence of phytol, 4a,7,7,10a-tetramethyldodecahydrobenzo[f]-chromen-3-ol, phytol acetate, solasodine glucoside, cassine, veratramine and solasodine acetate. Amongst these compounds, solasodine glucoside had the best binding energy (ΔG) with the selected diabetes-linked enzymes via molecular docking simulation.

CONCLUSION

Data from this study demonstrate the antidiabetic effects of S. petersiana leaf extract via the modulation of the dysregulated indices involved in type 2 diabetes and its associated complications. Although it has been shown safe in animals, further toxicological studies are required to ensure its safety for diabetes management in humans.

Early Detection Is the Best Prevention-Characterization of Oxidative Stress in Diabetes Mellitus and Its Consequences on the Cardiovascular System

Previous studies demonstrated an important role of oxidative stress in the pathogenesis of cardiovascular disease (CVD) in diabetic patients due to hyperglycemia. CVD remains the leading cause of premature death in the western world. Therefore, diabetes mellitus-associated oxidative stress and subsequent inflammation should be recognized at the earliest possible stage to start with the appropriate treatment before the onset of the cardiovascular sequelae such as arterial hypertension or coronary artery disease (CAD). The pathophysiology comprises increased reactive oxygen and nitrogen species (RONS) production by enzymatic and non-enzymatic sources, e.g., mitochondria, an uncoupled nitric oxide synthase, xanthine oxidase, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX). Considering that RONS originate from different cellular mechanisms in separate cellular compartments, adequate, sensitive, and compartment-specific methods for their quantification are crucial for early detection. In this review, we provide an overview of these methods with important information for early, appropriate, and effective treatment of these patients and their cardiovascular sequelae.

Hyperglycemia enhances the generation of ROS and RNS that impair antioxidant power and cause oxidative damage in human erythrocytes

Hyperglycemia is a state in which excess glucose circulates in blood. Erythrocytes are in direct contact with this high glucose concentration and are greatly affected by it. We have examined the effect of hyperglycemic condition on isolated human erythrocytes under in vitro conditions. Erythrocytes were incubated with different concentrations of glucose (5, 15, 30, 45 mmol/L) for 24 h, and several biochemical parameters were determined. Treatment with high glucose concentrations increased heme degradation and methemoglobin level, while methemoglobin reductase activity was decreased. A significant increase in protein oxidation and lipid hydroperoxides with a decrease in total sulfhydryl content was seen. This suggested the generation of oxidative stress, which was confirmed by an enhanced production of reactive oxygen and nitrogen species. Hyperglycemia led to a significant decline in the antioxidant power of erythrocytes, lowering their ability to quench free radicals and reduce metal ions to lower oxidation states. The plasma membrane redox system was upregulated, while ascorbate free radical reductase activity was lowered. Glucose exposure inhibited the enzymes of glycolysis and hexose monophosphate shunt. Electron microscopy showed morphological changes resulting in the formation of echinocytes. Thus, the hyperglycemic condition generates reactive species that oxidize proteins, hemoglobin, and lipids; impair the total antioxidant capacity; and alter morphology in human erythrocytes.

The Emerging Role of Salivary Oxidative Stress Biomarkers as Prognostic Markers of Periodontitis: New Insights for a Personalized Approach in Dentistry

Periodontitis is a multifactorial and infective oral disease that leads to the destruction of periodontal tissues and tooth loss. Although the treatment of periodontitis has improved recently, the effective treatment of periodontitis and the periodontitis-affected periodontal tissues is still a challenge. Therefore, exploring new therapeutic strategies for a personalized approach is urgent. For this reason, the aim of this study is to summarize recent advances and the potential of oxidative stress biomarkers in the early diagnosis and personalized therapeutic approaches in periodontitis. Recently, ROS metabolisms (ROMs) have been studied in the physiopathology of periodontitis. Different studies show that ROS plays a crucial role in periodontitis. In this regard, the reactive oxygen metabolites (ROMs) started to be searched for the measures of the oxidizing capacity of the plasma understood as the total content of oxygen free radicals (ROS). The oxidizing capacity of plasma is a significant indicator of the body's oxidant state as well as homocysteine (Hcy), sulfur amino acid, which has pro-oxidant effects as it favors the production of superoxide anion. More specifically, the thioredoxin (TRX) and peroxiredoxin (PRX) systems control reactive oxygen species (ROS), such as superoxide and hydroxyl species, to transduce redox signals and change the activities of antioxidant enzymes to remove free radicals. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), among other antioxidant enzymes, change their activity when ROS are produced in order to neutralize free radicals. The TRX system is triggered and transduces redox signals to do this.

Analysis of reactive aldehydes in urine and plasma of type-2 diabetes mellitus patients through liquid chromatography-mass spectrometry: Reactive aldehydes as potential markers of diabetic nephropathy

Introduction

Diabetes is a major public health issue that is approaching epidemic proportions globally. Diabetes mortality is increasing in all ethnic groups, irrespective of socio-economic class. Obesity is often seen as the main contributor to an increasing prevalence of diabetes. Oxidative stress has been shown to trigger obesity by stimulating the deposition of white adipose tissue. In this study, we measured reactive aldehydes by liquid chromatography-mass spectrometry (LC-MS), in the urine and plasma of type-2 diabetic mellitus (T2DM) patients, as potential surrogates of oxidative stress. Our hypothesis was that reactive aldehydes play a significant role in the pathophysiology of diabetes, and these reactive species, may present potential drug targets for patient treatment.

Materials and methods

Study participants [N = 86; control n = 26; T2DM n = 32, and diabetic nephropathy (DN) n = 28] were recruited between 2019 and 2020. Urine and blood samples were collected from all participants, including a detailed clinical history, to include patient behaviours, medications, and co-morbidities. Reactive aldehyde concentrations in urine and plasma were measured using pre-column derivatisation and LC-MS, for control, T2DM and DN patients.

Results

Reactive aldehydes were measured in the urine and plasma of control subjects and patients with T2DM and DN. In all cases, the reactive aldehydes under investigation; 4-HNE, 4-ONE, 4-HHE, pentanal, methylglyoxal, and glyoxal, were significantly elevated in the urine and serum of the patients with T2DM and DN, compared to controls (p < 0.001) (Kruskal-Wallis). Urine and serum reactive aldehydes were significantly correlated (≥0.7) (p < 0.001) (Spearman rho). The concentrations of the reactive aldehydes were significantly higher in plasma samples, when compared to urine, suggesting that plasma is the optimal matrix for screening T2DM and DN patients for oxidative stress.

Conclusion

Reactive aldehydes are elevated in the urine and plasma of T2DM and DN patients. Reactive aldehydes have been implicated in the pathobiology of T2DM. Therefore, if reactive aldehydes are surrogates of oxidative stress, these reactive aldehyde species could be therapeutic targets for potential drug development.

Parkin-mediated mitophagy is negatively regulated by FOXO3A, which inhibits Plk3-mediated mitochondrial ROS generation in STZ diabetic stress-treated pancreatic β cells

Diabetes mellitus (DM) is one of the most researched metabolic diseases worldwide. It leads to extensive complications such as cardiovascular disease, nephropathy, retinopathy, and peripheral and central nervous system through an inability to produce or respond to insulin. Although oxidative stress-mediated mitophagy has been reported to play an important role in the pathogenesis of DM, specific studies are still lacking as well as remain highly controversial. Here, we found that Parkin-mediated mitophagy in pancreatic β cells under streptozotocin (STZ)-diabetic stress was induced by Polo-like kinase 3 (Plk3) and inhibited by the transcription factor Forkhead Box O3A (FOXO3A). STZ stress induces mitochondrial recruitment of Parkin through Plk3-mediated mitochondrial reactive oxygen species (ROS) generation, which causes pancreatic cell damage. Conversely, FOXO3A acts as negative feedback to prevent diabetic stress by inhibiting Plk3. Meanwhile, antioxidants including N-acetylcysteine (NAC) and natural COA water scientifically block these mitochondrial ROS and mitochondrial recruitment of Parkin by inhibiting Plk3. Through a 3D organoid ex vivo model, we confirmed that not only ROS inhibitors but also mitophagy inhibitory factors such as 3-MA or Parkin deletion can compensate for pancreatic cell growth and insulin secretion under STZ diabetic stress. These findings suggest that the Plk3-mtROS-PINK1-Parkin axis is a novel mitophagy process that inhibits pancreatic β-cell growth and insulin secretion and FOXO3A and antioxidants may provide new alternatives for effective diabetes treatment strategies in the future.

Diabetes-Induced Cardiac Autonomic Neuropathy: Impact on Heart Function and Prognosis

Cardiovascular autonomic neuropathy (CAN) is a severe complication of the advance stage of diabetes. More than 50% of diabetic patients diagnosed with peripheral neuropathy will have CAN, with clinical manifestations including tachycardia, severe orthostatic hypotension, syncope, and physical exercise intolerance. Since the prevalence of diabetes is increasing, a concomitant increase in CAN is expected and will reduce quality of life and increase mortality. Autonomic dysfunction is associated with reduced baroreflex sensitivity and impairment of sympathetic and parasympathetic modulation. Various autonomic function tests are used to diagnose CAN, a condition without adequate treatment. It is important to consider the control of glucose level and blood pressure as key factors for preventing CAN progression. However, altered biomarkers of inflammatory and endothelial function, increased purinergic receptor expression, and exacerbated oxidative stress lead to possible targets for the treatment of CAN. The present review describes the molecular alterations seen in CAN, diagnosis, and possible alternative treatments.

Role of poly(ADP-ribose) polymerase-1 in regulating human islet cell differentiation

Poly(ADP-ribose) polymerase-1 (PARP1), a fundamental DNA repair enzyme, is known to regulate β cell death, replication, and insulin secretion. PARP1 knockout (KO) mice are resistant to diabetes, while PARP1 overactivation contributes to β cell death. Additionally, PARP1 inhibition (PARPi) improves diabetes complications in patients with type-2 diabetes. Despite these beneficial effects, the use of PARP1 modulating agents in diabetes treatment is largely neglected, primarily due to the poorly studied mechanistic action of PARP1 catalytic function in human β cell development. In the present study, we evaluated PARP1 regulatory action in human β cell differentiation using the human pancreatic progenitor cell line, PANC-1. We surveyed islet census and histology from PARP1 wild-type versus KO mice pancreas in a head-to-head comparison with PARP1 regulatory action for in-vitro β cell differentiation following either PARP1 depletion or its pharmacological inhibition in PANC-1-differentiated islet cells. shRNA mediated PARP1 depleted (SiP) and shRNA control (U6) PANC-1 cells were differentiated into islet-like clusters using established protocols. We observed complete abrogation of new β cell formation with absolute PARP1 depletion while its inhibition using the potent inhibitor, PJ34, promoted the endocrine β cell differentiation and maturation. Immunohistochemistry and immunoblotting for key endocrine differentiation players along with β cell maturation markers highlighted the potential regulatory action of PARP1 and augmented β cell differentiation due to direct interaction of unmodified PARP1 protein elicited p38 MAPK phosphorylation and Neurogenin-3 (Ngn3) re-activation. In summary, our study suggests that PARP1 is required for the proper development and differentiation of human islets. Selective inhibition with PARPi can be an advantage in pushing more insulin-producing cells under pathological conditions and delivers a potential for pilot clinical testing for β cell replacement cell therapies for diabetes.

Flavonoids' Dual Benefits in Gastrointestinal Cancer and Diabetes: A Potential Treatment on the Horizon?

Diabetes and gastrointestinal cancers (GI) are global health conditions with a massive burden on patients' lives worldwide. The development of both conditions is influenced by several factors, such as diet, genetics, environment, and infection, which shows a potential link between them. Flavonoids are naturally occurring phenolic compounds present in fruits and vegetables. Once ingested, unabsorbed flavonoids reaching the colon undergo enzymatic modification by the gut microbiome to facilitate absorption and produce ring fission products. The metabolized flavonoids exert antidiabetic and anti-GI cancer properties, targeting major impaired pathways such as apoptosis and cellular proliferation in both conditions, suggesting the potentially dual effects of flavonoids on diabetes and GI cancers. This review summarizes the current knowledge on the impact of flavonoids on diabetes and GI cancers in four significant pathways. It also addresses the synergistic effects of selected flavonoids on both conditions. While this is an intriguing approach, more studies are required to better understand the mechanism of how flavonoids can influence the same impaired pathways with different outcomes depending on the disease.

Resveratrol-like Compounds as SIRT1 Activators

The sirtuin 1 (SIRT1) activator resveratrol has emerged as a promising candidate for the prevention of vascular oxidative stress, which is a trigger for endothelial dysfunction. However, its clinical use is limited by low oral bioavailability. In this work, we have applied a previously developed computational protocol to identify the most promising derivatives from our in-house chemical library of resveratrol derivatives. The most promising compounds in terms of SIRT1 activation and oral bioavailability, predicted in silico, were evaluated for their ability to activate the isolated SIRT1 enzyme. Then, we assessed the antioxidant effects of the most effective derivative, compound 3d, in human umbilical vein endothelial cells (HUVECs) injured with H₂O₂ 100 µM. The SIRT1 activator 3d significantly preserved cell viability and prevented an intracellular reactive oxygen species increase in HUVECs exposed to the oxidative stimulus. Such effects were partially reduced in the presence of a sirtuin inhibitor, sirtinol, confirming the potential role of sirtuins in the activity of resveratrol and its derivatives. Although 3d appeared less effective than resveratrol in activating the isolated enzyme, the effects exhibited by both compounds in HUVECs were almost superimposable, suggesting a higher ability of 3d to cross cell membranes and activate the intracellular target SIRT1.

Heartwood Extract of Pterocarpus marsupium Roxb. Offers Defense against Oxyradicals and Improves Glucose Uptake in HepG2 Cells

Diabetes mellitus leads to cellular damage and causes apoptosis by oxidative stress. Heartwood extract of Pterocarpus marsupium has been used in Ayurveda to treat various diseases such as leprosy, diabetes, asthma, and bronchitis. In this study, we worked out the mechanism of the antidiabetic potential of methanolic heartwood extract of Pterocarpus marsupium (MPME). First, metabolic profiling of MPME was done using gas chromatography-mass spectrometry (GCMS), ultra-performance liquid chromatography-mass spectroscopy (UPLC-MS), and high-performance thin-layer chromatography (HPTLC) to identify phenols, flavonoids, and terpenoids in MPME. Biological studies were carried out in vitro using the HepG2 cell line. Many antidiabetic compounds were identified including Quercetin. Methanolic extract of MPME (23.43 µg/mL-93.75 µg/mL) was found to be safe and effective in reducing oxyradicals in HepG2 cells. A concentration of 93.75 µg/mL improved glucose uptake efficiently. A significant decrease in oxidative stress, cell damage, and apoptosis was found in MPME-treated HepG2 cells. The study suggests that the heartwood of Pterocarpus marsupium offers good defense in HepG2 cells against oxidative stress and improves glucose uptake. The results show the significant antidiabetic potential of MPME using a HepG2 cell model. The effect seems to occur by reducing oxidative stress and sensitizing the cells towards glucose uptake, hence lowering systemic glucose levels, as well as rescuing ROS generation.

Effect of folic acid and vitamin E on promoter DNA methylation and expression of TGF-β1, ESR-1 and CDH-1 in the uterus of STZ-induced diabetic rats

The present study is the first attempt made to investigate the effects of diabetes on expression and promoter DNA methylation of TGF-β1, ESR-1, and CDH-1 genes and also the effects of folic acid (FA) and vitamin E (Vit E) supplementations on improving diabetes mellitus. STZ-induced diabetic rats were treated with Vit E (200 mg/kg/day) and FA (25 mg/kg/day) for 8 weeks and expression and DNA methylation of TGF-β1, ESR-1, and CDH-1 genes in uterus were analysed. Data indicated that diabetes increases the expression of TGFβ-1 and ESR-1 and decreases CDH-1 expression and TGFβ-1 promoter methylation in the uterus of rats. Vit E and FA improved the negative effects of diabetes by decreasing the expression of TGFβ-1 and ESR-1 and increasing that of CDH-1 in diabetic rats. In conclusion, these findings emphasise that Vit E and FA supplementations could improve negative effects caused by diabetes on uterus function and fertility in diabetic rats.

The mechanisms of glycolipid metabolism disorder on vascular injury in type 2 diabetes

Patients with diabetes have severe vascular complications, such as diabetic nephropathy, diabetic retinopathy, cardiovascular disease, and neuropathy. Devastating vascular complications lead to increased mortality, blindness, kidney failure, and decreased overall quality of life in people with type 2 diabetes (T2D). Glycolipid metabolism disorder plays a vital role in the vascular complications of T2D. However, the specific mechanism of action remains to be elucidated. In T2D patients, vascular damage begins to develop before insulin resistance and clinical diagnosis. Endothelial dysregulation is a significant cause of vascular complications and the early event of vascular injury. Hyperglycemia and hyperlipidemia can trigger inflammation and oxidative stress, which impair endothelial function. Furthermore, during the pathogenesis of T2D, epigenetic modifications are aberrant and activate various biological processes, resulting in endothelial dysregulation. In the present review, we provide an overview and discussion of the roles of hyperglycemia- and hyperlipidemia-induced endothelial dysfunction, inflammatory response, oxidative stress, and epigenetic modification in the pathogenesis of T2D. Understanding the connections of glucotoxicity and lipotoxicity with vascular injury may reveal a novel potential therapeutic target for diabetic vascular complications.

Tridax procumbens Ameliorates Streptozotocin-Induced Diabetic Neuropathy in Rats via Modulating Angiogenic, Inflammatory, and Oxidative Pathways

Tridax procumbens (TP) is a traditional Indian therapeutic plant and was evaluated for its blood glucose lowering abilities, as well as for its ability to curb diabetic neuropathy (DN). Administrating 45 mg/kg body weight of streptozotocin (STZ) intraperitoneally for four weeks, DN was induced in Wistar rats. After the rats' tails were clipped, the blood glucose levels were measured. Body weight and urine volume were also assessed. Oxidative stress makers such as superoxide dismutase (SOD), thiobarbituric acid reactive substances (TBARS), catalase (CAT), inflammatory cytokines for instance tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were estimated. Further, protein kinase C (PKC-β) and vascular endothelial growth factor (VEGF) were also estimated as angiogenic markers. Behavioral parameters were also evaluated by using cold allodynia using acetone test, hot allodynia using Eddy's hot plate, grip strength test using Rota rod, and hyperalgesia test using Tail flick technique. The statistical assessment of findings was done employing one-way (ANOVA) analysis of variance, and subsequently Turkey as post hoc with GraphPad Prism software package. The ingestion of TP for 1 month in DN rats stemmed in a substantial decline in blood glucose concentrations matched to nontreated rats with DN. There had been a considerable improvement in DN as evident from the finding from biochemical markers. The serum level of antioxidant defense enzymes was significantly increased, while the activities of TBARS had been substantially reduced in the TP treated rats with DN. TP averted DN-triggered surge levels of TNF-α and IL-6 in the serum. Further, PKC-β and VEGF concentrations had been also reduced by the treatment TP. The findings of this research demonstrated that the restorative impact of TP on DN rats might be linked to the anti-inflammatory and antioxidative antiangiogenic retorts.

Oxidative Stress and DNA Damage in Peripheral Blood Mononuclear Cells from Normal, Obese, Prediabetic and Diabetic Persons Exposed to Thyroid Hormone In Vitro

Diabetes, a chronic group of medical disorders characterized byhyperglycemia, has become a global pandemic. Some hormones may influence the course and outcome of diabetes, especially if they potentiate the formation of reactive oxygen species (ROS). There is a close relationship between thyroid disorders and diabetes. The main objective of this investigation was to find out whether peripheral blood mononuclear cells (PBMCs) are more prone to DNA damage by triiodothyronine (T₃) (0.1, 1 and 10 μM) at various stages of progression through diabetes (obese, prediabetics, and type 2 diabetes mellitus—T2DM persons). In addition, some biochemical parameters of oxidative stress (catalase-CAT, thiobarbituric acid reactive substances—TBARS) and lactate dehydrogenase (LDH) were evaluated. PBMCs from prediabetic and diabetic patients exhibited increased sensitivity for T₃ regarding elevated level of DNA damage, inhibition of catalase, and increase of TBARS and LDH. PBMCs from obese patients reacted in the same manner, except for DNA damage. The results of this study should contribute to a better understanding of the role of thyroid hormones in the progression of T2DM.

d-Allulose Ameliorates Hyperglycemia Through IRE1α Sulfonation-RIDD-Sirt1 Decay Axis in the Skeletal Muscle

Aims: The skeletal muscle maintains glucose disposal via insulin signaling and glucose transport. The progression of diabetes and insulin resistance is critically influenced by endoplasmic reticulum (ER) stress. d-Allulose, a low-calorie sugar substitute, has shown crucial physiological activities under conditions involving hyperglycemia and insulin resistance. However, the molecular mechanisms of d-allulose in the progression of diabetes have not been fully elucidated. Here, we evaluated the effect of d-allulose on hyperglycemia-associated ER stress responses in human skeletal myoblasts (HSkM) and db/db diabetic and high-fat diet-fed mice. Results: d-allulose effectively controlled glycemic markers such as insulin and hemoglobin A1c (HbA1c), showing anti-diabetic effects by inhibiting the disruption of insulin receptor substrate (IRS)-1 tyrosine phosphorylation and glucose transporter 4 (GLUT4) expression, in which the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt) pathway is involved. The levels of glucose dysmetabolism-based NADPH oxidase, such as NADPH-dependent oxidoreductase (Nox) 4, were highly increased, and their interaction with IRE1α and the resultant sulfonation-regulated IRE1-dependent decay (RIDD)-Sirt1 decay were also highly increased under diabetic conditions, which were controlled with d-allulose treatment. Skeletal muscle cells grown with a high glucose medium supplemented with d-allulose showed controlled IRE1α sulfonation-RIDD-Sirt1 decay, in which Nox4 was involved. Innovation and Conclusion: The study observations indicate that d-allulose contributes to the muscular glucose disposal in the diabetic state where ER-localized Nox4-induced IRE1α sulfonation results in the decay of Sirt1, a core factor for controlling glucose metabolism. Antioxid. Redox Signal. 37, 229-245.

The Effect of Wet Cupping (Al-hijamah) and Limonene on Oxidative Stress and Biochemical Parameters in Diabetic Rats

Background: According to the international diabetes federation, 629 million adults will suffer from diabetes by 2045. Wet cupping therapy is a combination of bleeding and dry cupping and has been used in traditional medicine as a complementary therapy for diabetes. Limonene was shown to have both antioxidant and antidiabetic activity but its potential alongside other treatments has not been thoroughly explored. Objectives: Although wet-cupping therapy is widely used under different conditions, its potential in the treatment of diabetes is not well-examined. Methods: Male Wistar rats were then injected with alloxan and nicotinamide to induce diabetes. After cupping, the rats’ serum nitric oxide, creatinine, SGPT, SGOT, cholesterol, triglyceride, glucose, GPX, urea, and HDL levels were determined. The glutathione, catalase, glutathione peroxidase, malondialdehyde, and protein level of the serum, renal, and liver were then measured. Results: The results showed a significant differences in serum glucose levels among the diabetic rats receiving wet cupping and limonene, in serum glutathione levels in diabetic rats receiving limonene or limonene and wet cupping compared to the diabetic rats, in liver GSH levels in control rats receiving limonene and wet cupping, in the liver GPX activity in control rats receiving limonene, and in liver catalase activity in control rats receiving limonene and wet cupping compared to control group. There was no significant change in serum NO, protein, creatinine, SGPT, SGOT, cholesterol, triglyceride MDA, urea, catalase, HDL, renal GSH, MDA, catalase, liver protein, and MDA Level. Conclusions: The findings of the present study suggested that a combination of limonene and wet cupping therapy could be presented as an agent to lower elevated blood glucose levels in diabetic rats. Further clinical studies are required to confirm the findings.

Protective Role of Mitochondrial Uncoupling Proteins against Age-Related Oxidative Stress in Type 2 Diabetes Mellitus

The accumulation of oxidative damage to DNA and other biomolecules plays an important role in the etiology of aging and age-related diseases such as type 2 diabetes mellitus (T2D), atherosclerosis, and neurodegenerative disorders. Mitochondrial DNA (mtDNA) is especially sensitive to oxidative stress. Mitochondrial dysfunction resulting from the accumulation of mtDNA damage impairs normal cellular function and leads to a bioenergetic crisis that accelerates aging and associated diseases. Age-related mitochondrial dysfunction decreases ATP production, which directly affects insulin secretion by pancreatic beta cells and triggers the gradual development of the chronic metabolic dysfunction that characterizes T2D. At the same time, decreased glucose oxidation in skeletal muscle due to mitochondrial damage leads to prolonged postprandial blood glucose rise, which further worsens glucose homeostasis. ROS are not only highly reactive by-products of mitochondrial respiration capable of oxidizing DNA, proteins, and lipids but can also function as signaling and effector molecules in cell membranes mediating signal transduction and inflammation. Mitochondrial uncoupling proteins (UCPs) located in the inner mitochondrial membrane of various tissues can be activated by ROS to protect cells from mitochondrial damage. Mitochondrial UCPs facilitate the reflux of protons from the mitochondrial intermembrane space into the matrix, thereby dissipating the proton gradient required for oxidative phosphorylation. There are five known isoforms (UCP1-UCP5) of mitochondrial UCPs. UCP1 can indirectly reduce ROS formation by increasing glutathione levels, thermogenesis, and energy expenditure. In contrast, UCP2 and UCP3 regulate fatty acid metabolism and insulin secretion by beta cells and modulate insulin sensitivity. Understanding the functions of UCPs may play a critical role in developing pharmacological strategies to combat T2D. This review summarizes the current knowledge on the protective role of various UCP homologs against age-related oxidative stress in T2D.

Fu Brick Tea Manages HFD/STZ-Induced Type 2 Diabetes by Regulating the Gut Microbiota and Activating the IRS1/PI3K/Akt Signaling Pathway

The antidiabetic effects of Fu brick tea aqueous extract (FTE) and its underlying molecular mechanism in type 2 diabetes mellitus (T2DM) mice were investigated. FTE treatment significantly relieved dyslipidemia, insulin resistance (IR), and hepatic oxidative stress caused by T2DM. FTE also ameliorated the T2DM-induced gut dysbiosis by decreasing the Firmicutes/Bacteroidota (F/B) ratio at the phylum level and promoting the proliferation of Bifidobacterium, Parabacteroides, and Roseburia at the genus level. Besides, FTE significantly improved colonic short-chain fatty acid levels of T2DM mice. Furthermore, the antidiabetic effects of FTE were proved to be mediated by the IRS1/PI3K/Akt and AMPK-mediated gluconeogenesis signaling pathways. Metabolomics analysis illustrated that FTE recovered the levels of 28 metabolites associated with T2DM to the levels of normal mice. Taken together, these findings suggest that FTE can alleviate T2DM by reshaping the gut microbiota, activating the IRS1/PI3K/Akt pathway, and regulating intestinal metabolites.