Reactive metabolites and antioxidant gene polymorphisms in Type 2 diabetes mellitus

A Sequentially Activated Probe for Imaging of Superoxide Anion and Peroxynitrite in PC12 Cells under Oxidative Stress

Superoxide anion (O2·-) and peroxynitrite (ONOO-), two important oxidants under oxidative stress, coexist in complex cell and organism systems, playing crucial roles in various physiological and pathological processes, particularly in neurodegenerative diseases. Despite the absence of robust molecular tools capable of simultaneously visualizing O2·- and ONOO- in biosystems, the relationship between these two species remains understudied. Herein, we present sequentially activated fluorescent probe, DHX-SP, which exhibits exceptional selectivity and sensitivity toward O2·- and ONOO-. This probe enables precise imaging of these species in living PC12 cells under oxidative stress conditions using distinct fluorescence signal combinations. Furthermore, the probe DHX-SP has the ability to visualize changes in O2·- and ONOO- levels during ferroptosis of PC12 cells and in the Parkinson's disease model. These findings establish a connection between the crosstalk of the phosphorus group of O2·- and ONOO- in PC12 cells under oxidative stress.

The Mechanism of Pyroptosis and Its Application Prospect in Diabetic Wound Healing

Pyroptosis defines a form of pro-inflammatory-dependent programmed cell death triggered by gasdermin proteins, which creates cytoplasmic pores and promotes the activation and accumulation of immune cells by releasing several pro-inflammatory mediators and immunogenic substances upon cell rupture. Pyroptosis comprises canonical (mediated by Caspase-1) and non-canonical (mediated by Caspase-4/5/11) molecular signaling pathways. Numerous studies have explored the contributory roles of inflammasome and pyroptosis in the progression of multiple pathological conditions such as tumors, nerve injury, inflammatory diseases and metabolic disorders. Accumulating evidence indicates that the activation of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome results in the activation of pyroptosis and inflammation. Current evidence suggests that pyroptosis-dependent cell death plays a progressive role in the development of diabetic complications including diabetic wound healing (DWH) and diabetic foot ulcers (DFUs). This review presents a brief overview of the molecular mechanisms underlying pyroptosis and addresses the current research on pyroptosis-dependent signaling pathways in the context of DWH. In this review, we also present some prospective therapeutic compounds/agents that can target pyroptotic signaling pathways, which may serve as new strategies for the effective treatment and management of diabetic wounds.

Necrosis, netosis, and apoptosis in pulmonary tuberculosis and type-2 diabetes mellitus. Clues from the patient's serum

Pulmonary tuberculosis (PTB) and type 2 diabetes mellitus (T2DM) are two inflammatory diseases whose pathology involves neutrophils (NEU) as key participants. Countless inflammatory elements produced at the lesion sites leak into the blood and are distributed systemically. The study aimed to investigate the effect of the serum of patients with PTB, T2DM, and PTB + T2DM on the cellular and nuclear morphology of healthy NEU. Monolayers of NEU were prepared and incubated with sera from PTB (n꓿ 10), T2DM (n꓿10), PTB + T2DM (n꓿ 10) patients, or sera from healthy people (n = 10). Monolayers were stained for histones, elastase, and myeloperoxidase for NETosis, annexin V for apoptosis, and Iris fuchsia for necrosis. Hoechst stain (DNA) was used to identify the nuclear alterations. Necrosis was the predominant alteration. Sera from PTB + T2DM were the most potent change inducers. Normal sera did not induce cell alterations. The blood of TBP and T2DM patients carries a myriad of abnormal elements that induce necrosis of NEU in normal people, thus reflecting what might occur in the neutrophils of the patients themselves. These findings reinforce the participation of NEU in the pathology of these diseases. Necrosis is expected to be the most frequent neutrophil-induced alteration in tuberculosis and diabetes mellitus.

Effects of potentilla discolor bunge extracts on oxidative stress and glycolipid metabolism in animal models of diabetes: a systematic review and meta-analysis

Background/aim: Potentilla discolor Bunge (PDB) is an ancient herb of traditional Chinese medicine. Studies have suggested that extracts of PDB may ameliorate diabetes mellitus (DM). This study aimed to systematically assess the efficacy of PDB extracts on glycolipid metabolism and oxidative stress in animal models of diabetes and to provide evidence-based references for the use of PDB extracts. Methods: This study followed the PRISMA 2020 guidelines. Studies were searched from eight databases until January 2023. Statistical analysis was performed using StataSE 15.0 and RevMan 5.3. The standard mean difference (SMD) and 95% confidence intervals (CI) were computed using the random-effects model. SYRCLE's risk of bias tool was used to assess the risk of bias. Results: In total, 32 studies with 574 animals were included. The findings demonstrated that PDB extracts considerably lowered fasting blood glucose (SMD: -3.56, 95%CI: -4.40 to -2.72, p < 0.00001); insulin resistance (SMD: -3.19, 95% CI: -5.46 to -0.92, p = 0.006), total cholesterol (SMD: -2.18, 95%CI: -2.89 to -1.46, p < 0.00001), triglyceride (SMD: -1.48, 95% CI: -2.01 to -0.96, p < 0.00001), low-density lipoprotein cholesterol (SMD: -1.80, 95% CI: -2.58 to -1.02], p < 0.00001), malondialdehyde (SMD: -3.46, 95% CI: -4.64 to -2.29, p < 0.00001) and free fatty acid levels (SMD: -3.25, 95%CI: -5.33 to -1.16, p = 0.002), meanwhile, increased insulin sensitivity index (SMD: 2.51 95% CI: 1.10 to 3.92, p = 0.0005), body weight (SMD:1.20, 95% CI: 0.38 to 2.01, p = 0.004), and the levels of high-density lipoprotein cholesterol (SMD: 1.04, 95% CI: 0.40 to 1.69, p = 0.001), superoxide dismutase (SMD:2.63, 95% CI: 1.53 to 3.73, p < 0.00001), glutathione peroxidase (SMD:1.13, 95%CI: 0.42 to1.83, p = 0.002), and catalase (SMD:0.75, 95% CI: 0.11 to 1.40], p = 0.02). Conclusion: These findings suggest that PDB extracts can ameliorate DM by improving glycolipid metabolism and oxidative stress. PDB may be a promising medication for DM; however, due to significant heterogeneity between studies, these findings should be interpreted with caution. In addition, future well-designed trials should determine which components of the PDB play a major role in ameliorating DM and whether these benefits persist in humans. Systematic Review Registration: https://www.crd.york.ac.uk/prospero, CRD42023379391.

Umbilical cord mesenchymal stem cell-derived apoptotic extracellular vesicles ameliorate cutaneous wound healing in type 2 diabetic mice via macrophage pyroptosis inhibition

BACKGROUND

Delayed healing of diabetic cutaneous wounds is one of the most common complications of type 2 diabetes mellitus (T2DM), which can bring great distress to patients. In diabetic patients, macrophages accumulate around skin wounds and produce NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasomes, which in turn undergo pyroptosis and produce inflammatory factors such as interleukin-1β that affect wound healing. Although our previous study revealed that apoptotic extracellular vesicles (ApoEVs) produced from mesenchymal stem cells (MSCs) improve cutaneous wound healing in normal C57BL/6 mice, whether ApoEVs can also improve diabetic wound healing remains unclear.

METHODS

Umbilical cord mesenchymal stem cells (UCMSCs) were cultured in vitro and apoptosis was induced. ApoEVs were extracted and identified and used in a T2DM mouse cutaneous wound model to evaluate the efficacy. The inhibitory effect of ApoEVs on macrophage pyroptosis was verified in vivo and in vitro, and the level of oxidative stress in macrophages was assessed to explore the mechanism by which ApoEVs play a role.

RESULTS

UCMSC-derived ApoEVs improved skin defect healing in T2DM mice. Moreover, UCMSC-derived ApoEVs inhibited macrophage pyroptosis in T2DM mice in vivo as well as in vitro under high-glucose culture conditions. In addition, we demonstrated that ApoEVs reduce oxidative stress levels, which is a possible mechanism by which they inhibit macrophage pyroptosis.

CONCLUSIONS

Our study confirmed that local application of UCMSC-derived ApoEVs improved cutaneous wound healing in T2DM mice. ApoEVs, as products of MSC apoptosis, can inhibit macrophage pyroptosis and regulate the death process by decreasing the level of oxidative stress.

Oxidative Stress, Reductive Stress and Antioxidants in Vascular Pathogenesis and Aging

This review is focused on the mechanisms that regulate health, disease and aging redox status, the signal pathways that counteract oxidative and reductive stress, the role of food components and additives with antioxidant properties (curcumin, polyphenols, vitamins, carotenoids, flavonoids, etc.), and the role of the hormones irisin and melatonin in the redox homeostasis of animal and human cells. The correlations between the deviation from optimal redox conditions and inflammation, allergic, aging and autoimmune responses are discussed. Special attention is given to the vascular system, kidney, liver and brain oxidative stress processes. The role of hydrogen peroxide as an intracellular and paracrine signal molecule is also reviewed. The cyanotoxins β-N-methylamino-l-alanine (BMAA), cylindrospermopsin, microcystins and nodularins are introduced as potentially dangerous food and environment pro-oxidants.

Boswellia serrata inhibits LPS-induced cardiotoxicity in H9c2 cells: Investigating role of anti-inflammatory and antioxidant effects

Sepsis-induced myocardial dysfunction is the main reason for mortality and morbidity. Recent investigations have shown that inflammation and oxidative stress play a central role in lipopolysaccharide (LPS)-induced cardiac injury pathophysiology. Gum-resin extracts of Boswellia serrata have been traditionally used in folk medicine for centuries to treat various chronic inflammatory diseases. The present study aimed to investigate the effects of B. serrata pretreatment on LPS-induced cardiac damage in H9c2 cells. The cells were pretreated with various concentrations of B. serrata (5-45 μg/ml) for 24 h and then stimulated with LPS (10 μg/ml) for another 24 h. Afterward, the levels of cell viability, tumor necrosis factor (TNF)-α, prostaglandin (PGE)-2, interleukin (IL)-1β, IL-6, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, nitric oxide (NO) and glutathione (GSH) were determined using enzyme-linked immunosorbent assay (ELISA), real time-PCR or appropriated biochemical methods. Our results demonstrated that LPS treatment caused a remarkable decrease in cell viability and GSH, and on the contrary, it led to a significant increase in the levels of gene and protein expression of inflammatory markers and NO. However, pretreatment of B. serrata (5, 15, and 45 μg/ml) decreased the levels of TNF-α, PGE2, IL-1β, COX-2, iNOS, IL-6, and NO production, while cell viability and GSH levels were increased. Taken together, our results demonstrated that B. serrata might be a potential therapeutic agent against LPS and endotoxemia-induced cardiac injury, through its anti-inflammatory and antioxidant properties.

Pharmacogenetic impact of SLC22A1 gene variant rs628031 (G/A) in newly diagnosed Indian type 2 diabetes patients undergoing metformin monotherapy

OBJECTIVES

Type 2 diabetes (T2D) imposes an enormous burden all over the world in both developed and developing countries. Inter-individual differences are attributed to polymorphisms in candidate genes resulting in altered absorption, transportation, distribution, and metabolism of oral antidiabetic drugs (OADs). Hence, the present study was undertaken to evaluate the pharmacogenetic impact of SLC22A1 gene variant rs628031 (G/A) on metformin monotherapy in newly diagnosed untreated T2D patients.

METHODS

Newly diagnosed T2D patients ( n  = 500) were enrolled according to inclusion/exclusion criteria. Initially, enrolled subjects were prescribed metformin monotherapy and followed up for at least 12 weeks. Response to metformin was evaluated in 478 patients who revisited for follow-up by measuring HbA1c.

RESULT

Out of 478 patients, 373 were responders to metformin monotherapy while 105 were non-responders. The pharmacogenetic impact was evaluated by genotype, haplotype, and pharmacogenetic analyses. 'GG' genotype and 'G' allele of SLC22A1 rs628031 G/A were observed in 48.8% and 67.7% of Met responders, respectively, while 20.9% and 49.1 % were in non-responders. Therefore, there was a 2.18-fold increase in the success rate of Met therapeutics.

CONCLUSION

Individuals carrying the 'GG' genotype or 'G' allele for SLC22A1 gene variant rs628031 G/A are better responders for Metformin monotherapy.

Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

Microalgae represent a growing innovative source of nutraceuticals such as carotenoids and phenolic compound which are naturally present within these single-celled organisms or can be induced in response to specific growth conditions. The presence of the unfavourable allelic variant in genes involved in the control of oxidative stress, due to one or more SNPs in gene encoding protein involved in the regulation of redox balance, can lead to pathological conditions such as insulin resistance, which, in turn, is directly involved in the pathogenesis of type 2 diabetes mellitus. In this review we provide an overview of the main SNPs in antioxidant genes involved in the promotion of insulin resistance with a focus on the potential role of microalgae-derived antioxidant molecules as novel nutritional tools to mitigate oxidative stress and improve insulin sensitivity.

1,2,4,5-Tetrazine-tethered probes for fluorogenically imaging superoxide in live cells with ultrahigh specificity

Superoxide (O₂^·-) is the primary reactive oxygen species in mammal cells. Detecting superoxide is crucial for understanding redox signaling but remains challenging. Herein, we introduce a class of activity-based sensing probes. The probes utilize 1,2,4,5-tetrazine as a superoxide-responsive trigger, which can be modularly tethered to various fluorophores to tune probe sensitivity and emission color. These probes afford ultra-specific and ultra-fluorogenic responses towards superoxide, and enable multiplexed imaging of various cellular superoxide levels in an organelle-resolved way. Notably, the probes reveal the aberrant superoxide generation in the pathology of myocardial ischemia/reperfusion injury, and facilitate the establishment of a high-content screening pipeline for mediators of superoxide homeostasis. One such identified mediator, coprostanone, is shown to effectively ameliorating oxidative stress-induced injury in mice with myocardial ischemia/reperfusion injury. Collectively, these results showcase the potential of 1,2,4,5-tetrazine-tethered probes as versatile tools to monitor superoxide in a range of pathophysiological settings.

Role and mechanism of REG2 depletion in insulin secretion augmented by glutathione peroxidase-1 overproduction

We previously reported a depletion of murine regenerating islet-derived protein 2 (REG2) in pancreatic islets of glutathione peroxidase-1 (Gpx1) overexpressing (OE) mice. The present study was to explore if and how the REG2 depletion contributed to an augmented glucose stimulated insulin secretion (GSIS) in OE islets. After we verified a consistent depletion (90%, p < 0.05) of REG2 mRNA, transcript, and protein in OE islets compared with wild-type (WT) controls, we treated cultured and perifused OE islets (70 islets/sample) with REG2 (1 μg/ml or ml · min) and observed 30-40% (p < 0.05) inhibitions of GSIS by REG2. Subsequently, we obtained evidences of co-immunoprecipitation, cell surface ligand binding, and co-immunofluorescence for a ligand-receptor binding between REG2 and transmembrane, L-type voltage-dependent Ca2+ channel (CaV1.2) in beta TC3 cells. Mutating the C-type lectin binding domain of REG2 or deglycosylating CaV1.2 removed the inhibition of REG2 on GSIS and(or) the putative binding between the two proteins. Treating cultured OE and perifused WT islets with REG2 (1 μg/ml or ml · min) decreased (p < 0.05) Ca2+ influx triggered by glucose or KCl. An intraperitoneal (ip) injection of REG2 (2 μg/g) to OE mice (6-month old, n = 10) decreased their plasma insulin concentration (46%, p < 0.05) and elevated their plasma glucose concentration (25%, p < 0.05) over a 60 min period after glucose challenge (ip, 1 g/kg). In conclusion, our study identifies REG2 as a novel regulator of Ca2+ influx and insulin secretion, and reveals a new cascade of GPX1/REG2/CaV1.2 to explain how REG2 depletion in OE islets could decrease its binding to CaV1.2, resulting in uninhibited Ca2+ influx and augmented GSIS. These findings create new links to bridge redox biology, tissue regeneration, and insulin secretion.

Comparison of the Response to Pulpal Sensibility Tests in Well-Controlled and Uncontrolled Type II Diabetes Mellitus Patients: A Cross-Sectional Study

Introduction

Diabetes mellitus is a metabolic disorder in which impairment of sensory fibers would be anticipated. The present study would assess the dental pulp response to cold and EPT sensibility tests in patients with type 2 diabetes, both well-controlled and uncontrolled.

Materials and Methods

One hundred two maxillary central incisors, belonging to participants aged 35–67 years, were included in this survey. At last, 51 diabetic patients were allocated to each group of well-controlled (HbA1C < 7) and uncontrolled (HbA1C ≥ 7). Electric and cold pulpal vitality tests were conducted for all teeth. Statistical analysis was performed with Student's t-test, the chi-square test, and the multiple linear regression model. A P value less than 0.05 was considered significant.

Results

Based on the results of this study, the mean value of response to EPT was 4.51 ± 2.06 and 4.41 ± 1.85 in well-controlled and uncontrolled diabetic patients, respectively. Also, the pulpal responses to cold and EPT tests had no significant differences between the two groups (P > 0.05).

Conclusion

Tooth responses to the cold and EPT sensibility tests were not different in well-controlled and uncontrolled diabetic patients. Despite no statistically significant correlation, male diabetic patients in the uncontrolled group showed a lower sensory response threshold to EPT compared to a well-controlled group.

Association of Polymorphisms in Antioxidant Enzyme-Encoding Genes with Diabetic Nephropathy in a Group of Saudi Arabian Patients with Type II Diabetes Mellitus

Introduction

Purpose

Patients and Methods

Results

Conclusion

Aerobic Exercise Training Improves Microvascular Function and Oxidative Stress Parameters in Diet-Induced Type 2 Diabetic Mice

PURPOSE

Type 2 diabetic (T2D) patients have liver and adipose tissue microcirculation disturbances associated with metabolic dysfunction and disease progression. However, the potential role of aerobic training on hepatic and white adipose tissue (WAT) microcirculation and the underlying mechanisms have not been elucidated to date. Therefore, we investigated the role of aerobic training on liver and WAT microcirculation and AGE-RAGE modulation in T2D mice.

METHODS

The control group (CTL) was fed standard chow, and T2D was induced by feeding male C57BL/6 a high-fat, high-carbohydrate diet for 24 weeks. In the following 12 weeks, mice underwent aerobic training (CTL EX and T2D EX groups), or were kept sedentary (CTL and T2D groups). We assessed metabolic parameters, biochemical markers, oxidative damage, the AGE-RAGE axis, hepatic steatosis, hepatic stellate cells activation (HSC) and liver and WAT microcirculation.

RESULTS

Hepatic microcirculation was improved in T2D EX mice which were associated with improvements in body, liver and fat mass, blood pressure, hepatic steatosis and fibrosis, and decreased HSC and AGE-RAGE activation. In contrast, improvement in WAT microcirculation, that is, decreased leukocyte recruitment and increased perfusion, was associated with increased catalase antioxidant activity.

CONCLUSION

Physical training improves hepatic and adipose tissue microcirculatory dysfunction associated with T2D, likely due to downregulation of AGE-RAGE axis, decreased HSC activation and increased antioxidant activity.

The Effect of Aerobic Exercise on the Oxidative Capacity of Skeletal Muscle Mitochondria in Mice with Impaired Glucose Tolerance

METHODS

Male C57BL/6J mice were randomly divided into six different experimental groups (8 animals/group): (1) normal group (NOR), (2) normal control group (NC), (3) normal + exercise group (NE), (4) IGT group (IGT), (5) IGT control group (IC), and (6) IGT+ exercise group (IE).The exercise group received aerobic exercise for 8 weeks. After the intervention, a blood glucose meter was used to detect the level of glucose tolerance in the mouse's abdominal cavity; a biochemical kit was used to detect serum lipid metabolism indicators, malondialdehyde, and superoxide dismutase levels; the ELISA method was used to detect serum insulin and mouse gastrocnemius homogenate LDH, PDH, SDH, and CCO levels. Western blot method was used to detect the protein expression levels of NOX4, PGC-1α, and Mfn2 in the gastrocnemius muscle of mice.

RESULTS

(1) Mice with high-fat diet for 30 weeks showed impaired glucose tolerance, insulin resistance, and lipid metabolism disorders. The level of LDH, PDH, SDH, and CCO in the gastrocnemius homogenate of mice was reduced. The expressions of NOX4 protein were significantly upregulated, while the expressions of PGC-1α and Mfn2 proteins were significantly downregulated. (2) 8-week aerobic exercise improved the disorders of glucose and lipid metabolism in IGT mice and increased homogenized LDH, PDH, SDH, and CCO levels, and the expressions of NOX4, PGC-1α, and Mfn2 proteins in the gastrocnemius muscle of mice were reversed. It is speculated that aerobic exercise can accelerate energy metabolism.

CONCLUSION

(1) C57BL/6 mice were fed high fat for 30 weeks and successfully constructed a mouse model of reduced diabetes; the mice with reduced diabetes have impaired glucose tolerance, insulin resistance, and lipid metabolism disorders; (2) 8 weeks of aerobic exercise improve glucose tolerance, reduce glucose tolerance in mice, reduce insulin resistance, improve lipid metabolism disorders, and reduce oxidative stress; (3) 8-week aerobic exercise reduces skeletal muscle NOX4 expression and increases glucose tolerance; reduces the expression of LDH, PDH, SDH, and CCO in mouse skeletal muscle; increases the expression level of mitochondrial fusion protein 2 and PGC-1α; improves glucose tolerance; reduces energy metabolism of mouse skeletal muscle; reduces oxidative stress; and reduces insulin resistance. It is speculated that aerobic exercise can accelerate energy metabolism. This process may involve two aspects: firstly, increase the expression level of oxidative metabolism enzymes and promote the tricarboxylic acid cycle; secondly, increase the expression of Mfn2 and accelerate mitochondria fission or fusion to regulate energy metabolism, thereby reducing oxidative stress and insulin resistance.

Role of Glutathione S-transferase Mu 1 and Glutathione S-transferases Theta 1 Polymorphism in the Risk of Developing Type 2 Diabetes Mellitus at Universitas Sumatera Utara Hospital, Medan

BACKGROUND: Diabetes mellitus is associated with an increased production of reactive oxygen species (ROS) and a reduction in antioxidant defense. Glutathione S-transferases (GSTs) is group of multifunction antioxidant enzyme can be used as important biomarkers for DM..  GSTM1, T1 genes variant polymorphism result in decreased or loss of enzyme activity. AIM: The study aimed to evaluate the role of GSTM1 and GSTT1 gene polymorphism in the risk of developing T2DM. METHODS: GSTM1 and GSTT1 polymorphisms were genotyped in 87 T2DM patients and 87 healthy control group to analyze their association with T2DM susceptibility by using multiplex Polymerase Chain Reaction (PCR). PCR products were electrophoresed using agarose 2%. Odds ratio (OR) with 95% confidence interval (CI) and P value were calculated using SPSS software (version 21.0). RESULTS: The genotype distribution of GSTM1 and GSTT1 were not different between T2DM patients and healthy control group (p = 0.542, OR= 0.780, CI 95%=0.350-1.737 and p=0.879, OR=1.047, CI 95%=0.577-1.903). The genotype distribution of combination of GSTM1 and GSTT1 were also not not different between T2DM patients and healthy control group (p = 0.640, OR= 0.640, CI 95%=0.224-1.83 and p=0.551, OR=0.721, CI 95%=0.245-2.120. CONCLUSION: In summary, this study showed that GSTT1 null, GSTM1 null, the combination of GSTM1 null and GSTT1 null genotype or combination of GSTM1 null and GSTT1 positive (or contrary) did not have any risk of developing T2DM at Universitas Sumatera Utara Hospital, Medan.  

Gastroprotective effects of extract of Jasminum grandiflorum L. flower in HCl/EtOH-induced gastric mucosal ulceration mice

Jasminum grandiflorum L. is a medicinal plant used to treat hepatitis and gastritis, but the mechanisms underlying its protective effects against gastrointestinal mucosal damage remain to be elucidated. In this study, we analyzed the effects of four different extracts and two compounds from the flower of J. grandiflorum in a mouse model of HCl/EtOH-induced gastric ulcer. The flower extracts alleviated gastric mucosal ulceration by increasing PGE2 production and the activity of antioxidant enzymes, along with the suppression of reactive oxygen species (ROS) generation, lipid peroxidation, apoptosis-related proteins, pro-inflammatory cytokines and nitric oxide (NO) production.

Effect of fulvic acid on gastric mucosa damage caused by chronic water avoidance stress

We investigated the antioxidant and anti-ulcerogenic effects of fulvic acid (FA) on oxidative damage caused by water avoidance stress (WAS) in rat gastrointestinal mucosa. Three experimental groups were established: control (C), chronic stress (CS), and chronic stress + FA (CS + FA). After WAS, a single dose of FA was administered for 10 days to the CS + FA group. Samples of the pyloric region of the stomach were stained with hematoxylin and eosin (H & E) and periodic acid-Schiff (PAS). Immunohistochemical staining was performed for inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS). Total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) levels were measured biochemically. By light microscopy, we observed loss of gastric epithelial cells and greater polymorphonuclear cell migration into the mucosa in the CS group compared to the C group. We found intact epithelial cell structure and a thick superficial mucus layer in the CS + FA group compared to the CS group. These findings in the CS + FA group were similar to those for group C. iNOS staining was stronger in the CS group compared to the C group. TOS and OSI levels in the CS + FA group were decreased compared to the CS group, but TAS, SOD, GPx and CAT levels were increased. We found that WAS caused damage to epithelium and connective tissue of the stomach mucosa and that this damage was prevented by FA. Therefore, administration of FA appears to prevent stress induced damage to rat stomach.

Association of Val16Ala Polymorphism of Manganese Superoxide Dismutase (MnSOD) with Food Intake and Cardiometabolic Risk Factors in the Elderly in Primary Care in Porto Alegre

BACKGROUND

The aging process causes physiological changes on its own. The combination of an unhealthy lifestyle with the presence of genetic polymorphisms, such as the Val16Ala of the antioxidant enzyme manganese-dependent superoxide dismutase (MnSOD) may contribute to a greater occurrence of cardiometabolic risk factors.

OBJECTIVE

This study aimed to verify the association of Val16Ala-MnSOD polymorphism with food intake, caloric expenditure, and cardiometabolic risk factors in the elderly.

METHODS

A cross-sectional study with a sample size of 270 elderly individuals assisted in primary health care in the city of Porto Alegre, RS, Brazil. Val16Ala polymorphism, glucose, lipid profile, insulin, HOMA-IR, blood pressure, waist circumference, PCR-us, IL-6, food consumption, and caloric expenditure were evaluated.

RESULTS

The average age of the elderly was 68.6 ± 7.6 years. There were statistically significant differences regarding the consumption of two or more servings of fruits and vegetables daily between the elderly VV versus AV (P=0.017). There were also statistically significant differences regarding the consumption of two or more daily servings of legumes and eggs between the elderly AA versus VV (P=0.002). The median of insulin was higher in the elderly AA versus AV (P=0.025) and the median of HOMA-IR was higher in the elderly VV versus AV (P=0.029). AA elderly individuals had higher means of high-density lipoprotein (HDL-c) compared to AV (P=0.029).

CONCLUSION

The results suggest that Val16Ala -MnSOD polymorphism is associated with the consumption of fruits, vegetables, legumes, and eggs, as well as with cardiometabolic risk factors in the elderly.

Modification of pea dietary fiber by ultrafine grinding and hypoglycemic effect in diabetes mellitus mice

This study was designed to investigate the effects of ultrafine grinding on the physicochemical properties of pea dietary fiber (PDF) and the hypoglycemic effect of ultrafine grinding dietary fiber on diabetes mellitus (DM). So, the PDF was treated by ultrafine grinding technology, and its microstructure and physicochemical properties were determined. Then, the DM model was established, and the 4-week ultrafine grinded pea dietary fiber (UGPDF) diet intervention was conducted by using gavage and feeding. During this period, the blood glucose and body weight of the mice were measured, and an oral glucose tolerance test was measured on the last day. The biochemical blood indexes of the mice were determined, and the pancreas was stained with HE after dissecting. The results showed that after ultrafine grinding, the structure fragmentation, specific surface area increased, and UGPDF showed higher swelling ability as well as water and oil holding capacities. Simultaneously, UGPDF had a significant effect on reducing blood glucose and glycosylated hemoglobin in DM mice, improving the wasting state of mice and increasing the tolerance to glucose. Further, the results of the HE section showed that the pancreatic islet cells gradually returned to normal regular morphology. In biochemical blood indicators, UGPDF reduced TC and TG levels in the blood. This study provided a specific data basis for the following research on the hypoglycemic mechanism, and broadens the application field of PDF. PRACTICAL APPLICATION: The physicochemical properties of pea dietary fiber were improved by ultrafine grinding technology. Because of this, the application of pea dietary fiber in the field of hypoglycemic had a better effect, laying a foundation for the next research on hypoglycemic mechanism.

Pretreatment with Lactobacillus fermentum XY18 Relieves Gastric Injury Induced by HCl/Ethanol in Mice via Antioxidant and Anti-Inflammatory Mechanisms

Aim

Lactobacillus fermentum XY18 (LF-XY18) is a bacterial strain with satisfactory antioxidant properties in vitro that we previously isolated from Xinjiang yogurt. This article will explore the preventive effect of LF-XY18 on acute gastric injury and provide the basis for the innovative development and application of lactic acid bacteria (LAB).

Methods

Kunming mice underwent gastric injury induced by hydrochloric acid and ethanol. LF-XY18 isolated from yogurt in Xinyuan County in the Yili region of Xinjiang was subsequently administered intragastrically to mice for 2 weeks to explore the mechanism of LF-XY18 in preventing gastric injury via its antioxidant effects.

Results

There was decreased gastric juice volume, gastric injury area, and formation of gastric mucosal lesions in the LF-XY18 mice as compared to those in the control mice, while LF-XY18 prevented the decrease in the gastric juice pH value in mice. Compared with the gastric injury model group mice, LF-XY18 reduced the serum levels of motilin, substance P, interleukin-6, interleukin-12, tumor necrosis factor-α, and interferon-γ but increased the serum levels of somatostatin and vasoactive intestinal peptide. The activities of superoxide dismutase, glutathione peroxidase, glutathione, and nitric oxide were increased in the gastric tissue of the LF-XY18 mice compared with the control mice, but malondialdehyde activity was decreased in the LF-XY18 mice. Quantitative polymerase chain reaction analysis illustrated that in the gastric tissue of LF-XY18 mice, the messenger RNA (mRNA) expression of occludin, epidermal growth factor (EGF), EGF receptor, vascular EGF, inhibitor kappa-B-α, neuronal nitric oxide synthase, endothelial nitric oxide synthase, cuprozinc superoxide dismutase, manganese superoxide dismutase, and catalase was stronger than that in the control mice, but the mRNA expression of activated B cells (NF-κB), inducible nitric oxide synthase, and cyclooxygenase-2 was weaker than in the control mice.

Conclusion

These results indicate that LF-XY18 has a potential role in the prevention of gastric injury through antioxidant effects, and a high concentration (1.0 × 10⁹ CFU/kg b.w.) of LF-XY18 has a stronger anti-gastric injury effect than a low concentration (1.0 × 10⁸ CFU/kg b.w.).

Glutathione S-Transferase (GSTT1 rs17856199) and Nitric Oxide Synthase (NOS2 rs2297518) Genotype Combination as Potential Oxidative Stress-Related Molecular Markers for Type 2 Diabetes Mellitus

BACKGROUND

Deregulation of the antioxidant enzymes was implicated in pathogenesis and complications of type 2 diabetes mellitus (T2DM). The data relate the genetic variants of these enzymes to T2DM are inconsistent among various populations.

PURPOSE

We aimed to explore the association of 13 genetic variants of "superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and nitric oxide synthase (NOS)" with T2DM susceptibility and the available clinical laboratory data.

SUBJECTS AND METHODS

A total of 384 individuals were enrolled in this work. Different genotypes of the genes mentioned above were characterized using TaqMan OpenArray Genotyping assays on a Real-Time polymerase chain reaction system.

RESULTS

After age- and sex-adjustment, among the studied 13 variants, GSTT1 rs17856199 was associated with T2DM under homozygote (OR=3.42; 95% CI:1.04-11.2, p=0.031), and recessive (OR=3.57; 95% CI: 1.11-11.4, p=0.029) comparison models. The NOS2 rs2297518*A allele was more frequent among the T2DM cohort (58.1% vs 35.4%, p<0.001) and showed a dose-response effect; being heterozygote was associated with higher odds for developing DM (OR=4.06, 95% CI=2.13-7.73, p<0.001), whereas being AA homozygote had double the risk (OR=9.06, 95% CI=3.41-24.1, p<0.001). Combined NOS2 rs2297518*A and either GSTT1 rs17856199*A or *C genotype carriers were more likely to develop T2DM. Different associations with sex, BMI, hyperglycemia, and/or hyperlipidemia were evident. The principal component analysis revealed NOS2 rs2297518*G, old age, dyslipidemia, high systolic blood pressure, and elevated HbA1c were the main classifiers of T2DM patients.

CONCLUSION

The oxidative stress-related molecular markers, GSTT1 rs17856199 and NOS2 rs2297518 variants were significantly associated with T2DM risk and phenotype in the study population.

Hunan insect tea polyphenols provide protection against gastric injury induced by HCl/ethanol through an antioxidant mechanism in mice

The purposes of this study were to explore the preventive and treatment effects of Hunan insect tea polyphenols (HITPs) on gastric injury in mice induced by HCl/ethanol and to investigate their molecular mechanisms of action. Both HITPs and ranitidine inhibited the formation and further deterioration of gastric mucosal lesions, reduced the secretion of gastric juice, and raised gastric juice pH compared to the control. The HITPs-H treated group had lower serum levels of motilin, substance P, and endothelin than the control group, but they had higher serum levels of vasoactive intestinal peptide and somatostatin. Mice treated with HITPs had lower serum levels of cytokines interleukin (IL)-6, IL-12, tumor necrosis factor-α (TNF-α), and interferon-γ than the control group. The activities of superoxide dismutase (SOD), nitric oxide, and glutathione peroxidase (GSH-Px) were higher in the gastric tissues of HITP-treated mice, but the malondialdehyde content was lower. Quantitative PCR analysis indicated that the mRNA expression of occludin, epidermal growth factor (EGF), EGF receptor (EGFR), vascular EGF (VEGF), inhibitor kappaB-α, cuprozinc-superoxide dismutase, manganese-superoxide dismutase, GSH-Px, neuronal nitric oxide synthase, and endothelial NOS increased significantly in the gastric tissues of HITP-treated mice. However, the activated B cell, inducible NOS, cyclooxygenase-2, TNF-α, IL-1 beta, and IL-6 mRNA expression levels in the HITPs group were lower than those in the control group. The protective effect of a high concentration (200 mg per kg bw) of HITPs on gastric injury induced by HCl/ethanol was stronger than that of a low concentration (100 mg per kg bw) of HITPs. High-performance liquid chromatography (HPLC) revealed that the HITPs contained cryptochlorogenic acid, (-)-epicatechin gallate, and isochlorogenic acid C. Taken together, our findings indicate that the HITPs played a role in the prevention of gastric damage. The antioxidant effect of the HITPs contributed to their potential value in the prevention and treatment of gastric injury. HITPs have broad prospects as biologically active substances for food development.

Nutrigenetics of antioxidant enzymes and micronutrient needs in the context of viral infections

Sustaining adequate nutritional needs of a population is a challenging task in normal times and a priority in times of crisis. There is no 'one-size-fits-all' solution that addresses nutrition. In relevance to the COVID-19 (coronavirus disease 2019) pandemic crisis, viral infections in general and RNA viruses in particular are known to induce and promote oxidative stress, consequently increasing the body's demand for micronutrients, especially those related to antioxidant enzymic systems, thus draining the body of micronutrients, and so hindering the human body's ability to cope optimally with oxidative stress. Common polymorphisms in major antioxidant enzymes, with world population minor allele frequencies ranging from 0·5 to 50 %, are related to altered enzymic function, with substantial potential effects on the body's ability to cope with viral infection-induced oxidative stress. In this review we highlight common SNP of the major antioxidant enzymes relevant to nutritional components in the context of viral infections, namely: superoxide dismutases, glutathione peroxidases and catalase. We delineate functional polymorphisms in several human antioxidant enzymes that require, especially during a viral crisis, adequate and potentially additional nutritional support to cope with the pathological consequences of disease. Thus, in face of the COVID-19 pandemic, nutrition should be tightly monitored and possibly supplemented, with special attention to those carrying common polymorphisms in antioxidant enzymes.

Naringin ameliorates type 2 diabetes mellitus-induced steatohepatitis by inhibiting RAGE/NF-κB mediated mitochondrial apoptosis

AIMS

Recent findings have instituted the role of hyperglycemia-related AGE/RAGE and NF-κB in instigating reactive oxygen species (ROS) mediated mitochondrial dysfunction and apoptosis of hepatocyte, which leads to steatohepatitis. Naringin, a flavanone glycoside found to possess myriads of pharmacological benefits along with its antioxidant and anti-inflammatory properties. Consequently, we aimed to decipher the effect of naringin on RAGE/NF-κB mediated mitochondrial apoptosis in type 2 diabetes mellitus (T2DM)-induced steatohepatitis.

MAIN METHODS

Hepatic HepG2 cells were cultured in palmitic acid medium with and without naringin. Lipid content was examined by Oil Red O and Nile Red staining. Cellular apoptosis was determined by Annexin V-FITC/PI staining. An experimental T2DM-induced steatohepatitis was developed in Sprague Dawley rats by high-fat diet (HFD) for 12 weeks. The naringin was administrated orally at a dose of 100 mg/kg, daily for eight weeks. Glucose and insulin tolerance test was performed. Liver sections were stained by hematoxylin-eosin and picrosirius red. The mRNA and protein expression of RAGE and NF-κB were determined by qPCR, Immunofluorescence, and Immunoblotting. Mitochondrial membrane potential (MMP), cellular and mitochondrial ROS were measured by FACS.

KEY FINDINGS

Palmitic acid encountered HepG2 cells and HFD fed rats exhibited hyperlipidemia, insulin resistance, abnormal aminotransferases, steatosis, and fibrosis. Besides, the level of AGEs, RAGE, NF-κB, and oxidative stress were exacerbated. Moreover, MMP, cellular and mitochondrial ROS were altered in diabetic rats. Nevertheless, the naringin treatment ameliorated the steatohepatitis by improving the levels of aforementioned parameters.

SIGNIFICANCE

Collectively, these findings suggested anti-steatohepatitis potential of naringin in diabetics.

The Antioxidant Role of Soy and Soy Foods in Human Health

Oxidative stress seems to play a role in many chronic diseases, such as cardiovascular diseases, diabetes, and some cancers. Research is always looking for effective approaches in the prevention and treatment of these pathologies with safe strategies. Given the central role of nutrition, the identification of beneficial healthy foods can be the best key to having a safe and at the same time effective approach. Soy has always aroused great scientific interest but often this attention is galvanized by the interaction with estrogen receptors and related consequences on health. However, soy, soy foods, and soy bioactive substances seem to have antioxidant properties, suggesting their role in quenching reactive oxygen species, although it was frequently mentioned but not studied in depth. The purpose of this review is to summarize the scientific evidence of the antioxidant properties of soy by identifying the human clinical trials available in the literature. A total of 58 manuscripts were individuated through the literature search for the final synthesis. Soy bioactive substances involved in redox processes appear to be multiple and their use seems promising. Other larger clinical trials with adequate standardization and adequate choice of biomarkers will fill the gap currently existing on the suggestive role of soy in antioxidant mechanisms.

Association between High On-Aspirin Platelet Reactivity and Reduced Superoxide Dismutase Activity in Patients Affected by Type 2 Diabetes Mellitus or Primary Hypercholesterolemia

Platelet hyperactivation is involved in the established prothrombotic condition of metabolic diseases such as Type 2 Diabetes Mellitus (T2DM) and familial hypercholesterolemia (HC), justifying the therapy with aspirin, a suppressor of thromboxane synthesis through the irreversible inhibition of cyclooxygenase-1 (COX-1), to prevent cardiovascular diseases. However, some patients on aspirin show a higher than expected platelet reactivity due, at least in part, to a pro-oxidant milieu. The aim of this study was to investigate platelet reactivity in T2DM (n = 103) or HC (n = 61) patients (aspirin, 100 mg/day) and its correlation with biomarkers of redox function including the superoxide anion scavenger superoxide dismutase (SOD) and the in vivo marker of oxidative stress urinary 8-iso-prostaglandin F_2α. As results, in T2DM and HC subjects the prevalence of high on-aspirin platelet reactivity was comparable when both non-COX-1-dependent and COX-1-dependent assays were performed, and platelet reactivity is associated with a lower SOD activity that in a stepwise linear regression appears as the only predictor of platelet reactivity. To conclude, in T2DM and HC, similarly, the impairment of redox equilibrium associated with a decrease of SOD activity could contribute to a suboptimal response to aspirin.

Antidiabetic Potency, Antioxidant Effects, and Mode of Actions of Citrus reticulata Fruit Peel Hydroethanolic Extract, Hesperidin, and Quercetin in Nicotinamide/Streptozotocin-Induced Wistar Diabetic Rats

This study is aimed at assessing the antihyperglycemic, antihyperlipidemic, and antioxidant effects of Citrus reticulata (C. reticulata) fruit peel hydroethanolic extract and two flavonoids, hesperidin and quercetin, in nicotinamide (NA)/streptozotocin- (STZ-) induced type 2 diabetic rats. In addition, GC-MS and HPLC-MS analyses of the extract were performed and the results indicated the presence of multiple flavonoids including hesperidin, quercetin, naringin, and polymethoxylated flavones (nobiletin and tangeretin). To achieve the aim of the study, diabetic rats with NA/STZ-induced T2DM were orally treated with C. reticulata fruit peel hydroethanolic extract, hesperidin, and quercetin at a dose of 100 mg/kg b.w./day for four weeks. The treatments with C. reticulata fruit peel extract, hesperidin, and quercetin significantly ameliorated the impaired oral glucose tolerance; the elevated serum fructosamine level; the diminished serum insulin and C-peptide levels; the altered HOMA-IR, HOMA-IS, and HOMA-β cell function; the decreased liver glycogen content; the increased liver glucose-6-phosphatase and glycogen phosphorylase activities; the deleteriously affected serum lipid profile; the elevated serum AST and ALT activities; and the raised serum creatinine and urea levels in the diabetic rats. The treatments also produced remarkable improvement in the antioxidant defense system manifested by a decrease in the elevated liver lipid peroxidation and an increase in the lowered glutathione content and GPx, GST, and SOD activities. Furthermore, the three treatments enhanced the mRNA expression of GLUT-4 and the insulin receptor β-subunit, but only quercetin produced a significant increase in the expression of adiponectin in adipose tissue of diabetic rats. In conclusion, C. reticulata fruit peel hydroethanolic extract, hesperidin, and quercetin have potent antidiabetic effects which may be mediated through their insulinotropic effects and insulin-sensitizing actions. In addition, the alleviation of the antioxidant defense system by the extract, hesperidin, and naringin may have an important action to enhance the antidiabetic actions and to improve liver and kidney functions in NA/STZ-induced diabetic rats.

Oxidative stress and diabetes: antioxidative strategies

Diabetes mellitus is one of the major public health problems worldwide. Considerable recent evidence suggests that the cellular reduction-oxidation (redox) imbalance leads to oxidative stress and subsequent occurrence and development of diabetes and related complications by regulating certain signaling pathways involved in β-cell dysfunction and insulin resistance. Reactive oxide species (ROS) can also directly oxidize certain proteins (defined as redox modification) involved in the diabetes process. There are a number of potential problems in the clinical application of antioxidant therapies including poor solubility, storage instability and nonselectivity of antioxidants. Novel antioxidant delivery systems may overcome pharmacokinetic and stability problem and improve the selectivity of scavenging ROS. We have therefore focused on the role of oxidative stress and antioxidative therapies in the pathogenesis of diabetes mellitus. Precise therapeutic interventions against ROS and downstream targets are now possible and provide important new insights into the treatment of diabetes.

The ALOXA5AP gene (rs38022789) is associated with diabetic nephropathy in Slovenian patients with type 2 diabetes mellitus

BACKGROUND

Although the pathogenesis of diabetic nephropathy (DN) is multifactorial, and the precise mechanisms are unclear, there is a growing body of evidence suggesting that inflammatory processes and immune cells might be involved in the development and progression of DN. Leukotrienes (LTs) are a family of lipid mediators, which act as pro-inflammatory mediators. The study was designed to investigate the association between the polymorphism of the ALOX5 gene (rs12762303) and the ALOX5AP gene (rs3802278), and DN in patients with T2DM.

METHODOLOGY

651 subjects with diabetes mellitus type 2 (T2DM) were classified into two groups according to the presence of DN, and tested for ALOX5 and ALOX5AP gene polymorphisms using the KASPar genotyping chemistry with validated assay. Biochemical analyses were performed using standard biochemical methods.

RESULTS

Logistic regression analysis demonstrated that the carriers of the CC genotype had a 3.14 higher risk for DN compared to TT genotype. Serum cystatin C was found to be statistically significantly higher in cases with DN in comparison with subjects without DN (p < 0.001).

CONCLUSION

An association between the rs3803278 of the ALOX5AP gene and DN was found in Slovenian patients with T2DM. The rs3803278 CC allele appears to confer increased risk of DN possibly by increasing the production of LTs-potent drivers of inflammation.

Contribution of TGF-β1 and Effects of Gene Silencer Pyrrole-Imidazole Polyamides Targeting TGF-β1 in Diabetic Nephropathy

TGF-β1 has been known to induce diabetic nephropathy with renal fibrosis and glomerulosclerosis. DNA-recognized peptide compound pyrrole-imidazole (PI) polyamides as novel biomedicines can strongly bind promoter lesions of target genes to inhibit its transcription. We have developed PI polyamide targeting TGF-β1 for progressive renal diseases. In the present study, we evaluated the contribution of TGF-β1 in the pathogenesis of diabetic nephropathy, and examined the effects of PI polyamide targeting TGF-β1 on the progression of diabetic nephropathy in rats. For in vitro experiments, rat renal mesangial cells were incubated with a high (25 mM) glucose concentration. Diabetic nephropathy was established in vivo in eight-week-old Wistar rats by intravenously administering 60 mg/kg streptozotocin (STZ). We examined the effects of PI polyamide targeting TGF-β1 on phenotype and the growth of mesangial cells, in vitro, and the pathogenesis of diabetic nephropathy in vivo. High glucose significantly increased expression of TGF-β1 mRNA, changed the phenotype to synthetic, and increased growth of mesangial cells. STZ diabetic rats showed increases in urinary excretions of protein and albumin, glomerular and interstitial degenerations, and podocyte injury. Treatment with PI polyamide targeting TGF-β1 twice weekly for three months improved the glomerular and interstitial degenerations by histological evaluation. Treatment with PI polyamide improved podocyte injury by electron microscopy evaluation. These findings suggest that TGF-β1 may be a pivotal factor in the progression of diabetic nephropathy, and PI polyamide targeting TGF-β1 as a practical medicine may improve nephropathy.

Prophylactic effect of Lactobacillus plantarum KSFY06 on HCl/ethanol-induced gastric injury in mice

The present study was conducted to determine the prophylactic effect of Lactobacillus plantarum KSFY06 (LP-KSFY06) on HCl/ethanol-induced gastric injury in Kunming mice.

A novel mechanism of vitamin D anti-inflammatory/antioxidative potential in type 2 diabetic patients on metformin therapy

INTRODUCTION

The performed study focused on determining the effect of vitamin D supplementation on enzymes involved in both inflammation and reactive oxygen species (ROS) production and ROS degradation in patients with type 2 diabetes mellitus (T2DM).

MATERIAL AND METHODS

The 6-month follow-up, randomized, controlled study included 140 patients with T2DM, ≥ 30 years old, with good metabolic control, treated with metformin and lifestyle advice only. All patients were randomly assigned to two groups (70 each). Patients from the first group (Intervention group) were assigned to receive vitamin D3 50 000 IU or 14 000 IU regarding their vitamin D baseline levels. Patients from the second (Metformin) group continued to receive only metformin during the 6-month study period.

RESULTS

After 6 months, the myeloperoxidase activity was significantly lower and gradually decreased in the Intervention group by about 40%, compared to the baseline measurement (p = 0.015) and compared to the Metformin group (p = 0.001). After 6 months, the xanthine oxidase (XO) activity decreased significantly in the Intervention group compared to the baseline and 3^rd month levels (p < 0.001). In the Metformin group there was also a significant decrease in XO after 6 months compared to baseline (p < 0.001) and the 3^rd month (p = 0.003). The catalase activity significantly increased within the Intervention group only when comparing the 3^rd and 6^th month (p = 0.027).

CONCLUSIONS

Our study showed that vitamin D may improve endothelial dysfunction in patients with T2DM on metformin therapy by influencing two important factors implicated in the pathogenesis of diabetic complications - ROS production and inflammation, which can additionally contribute to a stable metabolic control during metformin therapy.

Rice Bran Derived Bioactive Compounds Modulate Risk Factors of Cardiovascular Disease and Type 2 Diabetes Mellitus: An Updated Review

Cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) are two chronic diseases that have claimed more lives globally than any other disease. Dietary supplementation of functional foods containing bioactive compounds is recognised to result in improvements in free-radical-mediated oxidative stress. Emerging evidence indicates that bioactive compounds derived from rice bran (RB) have therapeutic potential against cellular oxidative stress. This review aims to describe the mechanistic pathways behind CVD and T2DM development and the therapeutic potential of polyphenols derived from RB against these chronic diseases.

Antidiabetic and hypolipidemic efficacy of skin and seed extracts of Momordica cymbalaria on alloxan induced diabetic model in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Momordica cymbalaria, a wild vegetable belongs to the Cucurbitaceae family, has long been used as a food and a remedy for diabetes mellitus in the Asian native medicinal system.

AIM OF THE STUDY

This study aims to evaluate the efficacy of ethanolic extract of skin (EESK) and methanolic extract of seed (MESE) of M. cymbalaria (MC), for their hypoglycemic and hypolipidemic effects in alloxan induced diabetic rats.

MATERIALS AND METHODS

The diabetes induced rats were given skin and seed extracts at doses 250 and 500 mg/kg b.w. p.o. for 28 days. Alloxan monohydrate (120 mg/kg) was used to induce diabetes mellitus. Daily food and water intake were assessed. Blood glucose levels and body weights were measured every 7 days throughout the experiment. Antioxidant assays, different biochemical and glycemic parameters were evaluated. Histopathological studies on pancreas, liver and kidney were also studied.

RESULTS

Treatment of EESK and MESE showed dose significant decrease in fasting blood glucose level (FBG) in experimental diabetic animals with significant reduction in food and water intake and increase in body weight. Findings confirmed the hypoglycemic and hypolipidemic effects of EESK and MESE in the experimental groups. The impaired glucose tolerance and altered activities of the hepatic enzymes such as AST, ALT and ALP levels of diabetic rats were significantly improved by the administration of EESK and MESE. Oral treatment with MC extract for 28 days demonstrated significant protective effects on the lipid profile, biochemical parameters and antioxidant levels. Besides, biochemical findings were supported by histopathological investigations.

CONCLUSION

These results suggest that the treatment with EESK and MESE of MC at a dose of 500 mg/kg b.w. have better protective effects against hyperglycemia, hyperlipidemia and oxidative stress generated during diabetes justifying the use of the plant in traditional systems of medicine.

Preventive Effect of Anji White Tea Flavonoids on Alcohol-Induced Gastric Injury through Their Antioxidant Effects in Kunming Mice

Anji white tea (Camellia sinensis) is a traditional Chinese tea beverage, which is classified as green tea and contains an abundant amount of flavonoids. In this study, the preventive effect of Anji white tea flavonoids (AJWTFs) on ethanol/hydrochloric acid-induced gastric injury in mice was evaluated. The serum and gastric tissues of mice were analyzed using a biochemical kit and by quantitative polymerase chain reaction (qPCR). Observation of the appearance of the stomach indicated that AJWTFs could effectively reduce the area of gastric injury caused by ethanol/hydrochloric acid, and the inhibition rate of AJWTF on gastric injury increased with an increase in AJWTF concentration. The Anji white tea flavonoids could also reduce the volume and pH of gastric juice in mice with gastric injury. Biochemical results showed that AJWTFs could increase the superoxide dismutase (SOD) and glutathione (GSH) activities, as well as decrease the malondialdehyde (MDA) level, in the serum and liver of mice with gastric injury. Pathological observation confirmed that AJWTFs could inhibit the tissue damage caused by ethanol/hydrochloric acid in the stomach of mice. Further qPCR experiments also showed that AJWTFs could inhibit the decreases in neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), copper/zinc superoxide dismutase (Cu/Zn–SOD), manganese superoxide dismutase (Mn–SOD), catalase (CAT), and the increase in inducible nitric oxide synthase (iNOS) expression in the gastric tissue of mice caused by gastric injury. As observed, AJWTFs exerted a good preventive effect on alcohol-induced gastric injury in mice induced by ethanol/hydrochloric acid, and the effect is close to that of ranitidine. Anji white tea flavonoids present good antioxidant effect, which allows them to effectively prevent alcoholic gastric injury and be used as biologically active substances with a broad range of applications.

Glutathione peroxidase-1 inhibits transcription of regenerating islet-derived protein-2 in pancreatic islets

Our group previously demonstrated that overexpression of selenium-dependent glutathione peroxidase-1 (GPX1) in mice (OE) led to escalated glucose-stimulated insulin secretion and hyperinsulinemia. Because we found a strong correlation of this phenotype with a diminished expression of regenerating islet-derived protein 2 (REG2) in the OE pancreatic islets, the present study was to reveal underlying mechanisms for that down-regulation of REG2 by GPX1 as a major scavenger of reactive oxygen species. We first treated the OE and wild-type (WT) mice and their islets with ROS-generating diquat, streptozotocin, and H₂O₂ and ROS-scavenging ebselen and N-acetylcysteine (NAC). Their effects on pancreatic and islet REG2 protein and(or) secretion were opposite (P < 0.05). Thereafter, we identified 13 transcriptional factors with putative binding sites in the Reg2 proximate promoter, and found that only activator protein-1 (AP-1) and albumin D box-binding protein (DBP) mRNA and protein levels were affected (elevated) (P < 0.05) by the GPX1 overproduction in the OE pancreatic islets compared with the WT islets. Contrary to that of Reg2 expression, their mRNA abundances in the cultured islets were elevated (P < 0.05) by ebselen and NAC, but decreased (P < 0.05) by H₂O_2. Both AP-1 and DBP could bind to the Reg2 promoter at the location of -168 to 0 base pair (bp) in the OE islets. Deleting the AP-1 (-143/-137 and -60/-57 bp) and(or) DBP (-35/-29 bp) binding domains in the Reg2 promoter attenuated and(or) abolished the inhibition of Reg2 promoter activation by ebselen as the GPX1 mimic in βTC-3 cells. In conclusion, the down-regulation of Reg2 expression in the GPX1-overproducing pancreatic islets was mediated by a transcriptional inhibition of the gene through two ROS responsive transcription factors AP-1 and DBP. Our findings reveal GPX1 as a novel regulator of Reg2 expression, and linking these two previously-unrelated proteins will have broad biomedical implications.

Therapeutic effects of ethanolic extract from the green cocoon shell of silkworm Bombyx mori on type 2 diabetic mice and its hypoglycaemic mechanism

Diabetes mellitus is a clinically complex disease characterized by hyperglycaemia with disturbances in carbohydrate, fat and protein metabolism. The aim of this study was to determine the therapeutic effect of ethanolic extract (EE) from the green cocoon sericin layer of silkworm Bombyx mori on mice with type 2 diabetes mellitus (T2DM) and its hypoglycaemic mechanisms. The results showed that oral EE for 7 weeks had significant ameliorative effects on all the biochemical parameters studied in vivo. The levels of oral glucose tolerance and insulin tolerance were significantly improved. The hypoglycaemic rate in the 350 mg kg^-1 high dosage group was 39.38%. The levels of nuclear factor kappa B (NFκB), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) in the high dosage EE-treated group were significantly reduced, while activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were obviously increased. The islet area and the number of insulin-positive beta cells increased significantly in the high dose group. Furthermore, expression levels of insulin receptor (IR), insulin receptor substrate (IRS), phosphatidylinositide 3-kinase (PI3K), p-Akt and phospho-glycogen synthase kinase-3β (p-GSK3β) involved in insulin signalling were increased. Adenosine 5'-monophosphate-activated protein kinase (AMPK) and glucose transporter 4 (GLUT4) also were activated to regulate glucose metabolism in EE-treated groups. The levels of glucose 6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase (PEPCK) decreased, while the glucokinase (GK) level increased to promote glycolysis. The results clearly indicated that oral EE, especially at a high dose, could improve the glucose metabolism of T2DM by reducing inflammatory reactions, enhancing the antioxidant capacity and insulin sensitivity, and regulating the balance between glycolysis and gluconeogenesis, which means that EE has potential ameliorative effects on T2DM mice.

TNF-α (-308) Gene Polymorphism and Type 2 Diabetes Mellitus in Ethiopian Diabetes Patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disorder resulting from insulin insufficiency or function. Predisposing factors for T2DM are mainly genetic and environmental. Genetic polymorphism of cytokines like tumor necrosis factor-alpha (TNF-α) is suggestive of interference with insulin-sensitive glucose uptake and induces insulin resistance that ultimately could lead to T2DM. In this study, we assessed the effect of TNF-α (-308) G/A gene polymorphism and its association with the development of T2DM in an Ethiopian population.

METHODS

An institutional-based cross-sectional study was conducted on study subjects with T2DM and non-diabetic healthy controls. DNA was extracted and genotyping was carried out by using amplification refractory mutation system polymerase chain reaction. A genetic-polymorphism on TNF-α (-308) G/A with T2DM was evaluated by logistic regression and Student's t-test. A P-value <0.05 was considered as statistically significant.

RESULTS

In the present study, we observed a significant association between T2DM and TNF-α (-308) gene polymorphism's GG genotype [χ2 test P = 0.005, OR (95% CI) =2.667 (1.309-5.45d8)]. In contrast, no statistically significant differences were observed in the frequencies of genotypes AA and AG (χ2 test P=0.132 and 0.067, respectively). Moreover, T2DM individuals had higher concentrations of lipid profiles for those carrying the TNF-α (-308) GG genotype as compared to the control group.

CONCLUSION

TNF-α (-308) genetic polymorphism may be implicated in the genetic susceptibility for, as well as the development of T2DM and lipid metabolism in the Ethiopian population. Therefore, a large-scale study and early screening of TNF-α (-308) genetic polymorphism may help in early management and control of diabetes and related outcomes.

Skeletal muscle performance in metabolic disease: Microvascular or mitochondrial limitation or both?

One of the clearly established health outcomes associated with chronic metabolic diseases (eg, type II diabetes mellitus) is that the ability of skeletal muscle to maintain contractile performance during periods of elevated metabolic demand is compromised as compared to the fatigue-resistance of muscle under normal, healthy conditions. While there has been extensive effort dedicated to determining the major factors that contribute to the compromised performance of skeletal muscle with chronic metabolic disease, the extent to which this poor outcome reflects a dysfunctional state of the microcirculation, where the delivery and distribution of metabolic substrates can be impaired, versus derangements to normal metabolic processes and mitochondrial function, versus a combination of the two, represents an area of considerable unknown. The purpose of this manuscript is to present some of the current concepts for dysfunction to both the microcirculation of skeletal muscle as well as to mitochondrial metabolism under these conditions, such that these diverse issues can be merged into an integrated framework for future investigation. Based on an interpretation of the current literature, it may be hypothesized that the primary site of dysfunction with earlier stages of metabolic disease may lie at the level of the vasculature, rather than at the level of the mitochondria.

Do GST polymorphisms influence in the pathogenesis of diabetic nephropathy?

Diabetic patients often develop Diabetic Nephropathy (DN) despite severe long-lasting hyperglycemia, while others develop DN even under intensive insulin therapy. This indicates that factors other than chronic hyperglycemia may also contribute to the susceptibility to the development of DN. The purpose of this case-control study was to investigate the possible role of GSTM1 and GSTT1 deletion polymorphisms, and Single Nucleotide Polymorphism (SNP), GSTP1 313 A > G (Ile105Val), in DN susceptibility. Multiple logistic regression analysis revealed that the occurrence of GST polymorphisms in the Central Brazilian population was not associated with increased risk of DN. However, the presence GSTT1 null genotype suggest an increase trend in systolic blood pressure and opposite inference was observed for the GSTP1 genotype (Ile⁄Val or Val⁄Val). On the order hand, other studies may clarify the relationship of these polymorphisms with DN and help in the prevention of this disease.

Impaired glutathione-related antioxidant defenses in the arterial tissue of diabetic patients

We studied the specific enzymatic activities of selenium-dependent (GSH-Px) and -independent (GST-Px) glutathione peroxidase, glutathione reductase (GSSG-Red), and glutathione S-transferase (GST) in internal mammary arteries (IMArt) specimens obtained during coronary artery bypass surgery in 18 patients with type 2 diabetes mellitus as compared to 18 non-diabetic controls; vascular lipid peroxidation, namely fluorescent damage products of lipid peroxidation (FDPL) as 4-hydroxynonenal-related oxidative stress indicators, was also studied. Moreover, in other 16 diabetic patients and 16 controls, total glutathione (TGlut) was determined in IMArt specimens specifically homogenized in sulfosalycilic acid to prevent vascular GSH depletion. The activities of GSH-Px, GSSG-Red, and GST were significantly lower, and FDPL levels higher, in the arterial tissue of diabetic patients than in that of controls; GST-Px was undetectable. Such enzymatic activities were inversely correlated with vascular lipid peroxidation, highlighting their antioxidant role in the arterial tissue, as were HbA1c and FDPL levels with the enzymatic activities, suggesting that glycation, oxidant species and lipoperoxidation aldehydes may be involved in glutathione-related enzyme inactivation. Further, in the diabetic patients HbA1c was correlated directly with lipid peroxidation but inversely with TGlut of the arterial tissue. In the patients considered for vascular enzymatic activities and FDPL assay, 3/4-vessel coronary artery disease (CAD) as expression of atherosclerosis severity was present in 9 diabetic patients and in 3 controls. Notably, vascular glutathione-related enzymatic activities were significantly lower, and FDPL levels higher, in the 9 diabetic patients with 3/4-vessel CAD than in the 9 without, as well as in the total of 12 patients with 3/4-vessel CAD than in the total of 24 patients without. Moreover, vascular TGlut content was significantly lower in the diabetic than in the control patients. Three/4-vessel CAD was present in 6 diabetic patients and in 2 controls considered for determination of vascular Tglut content, which was significantly lower in the diabetic patients with 3/4-vessel CAD than in those without, as well in the total of 8 patients with 3/4-vessel CAD than in the total of 24 patients without. Thus, weakened glutathione-related antioxidant capacity and oxidative stress of the arterial tissue are associated with the severity of atherosclerosis. In conclusion, impaired glutathione-related antioxidant defenses of the arterial tissue occur in diabetic patients, eventually favoring vascular oxidative stress and the severity of atherosclerosis.

Influence of maternal consumption of different types of fatty acids during pregnancy and lactation on lipid and glucose metabolism of the 21-day-old male offspring in rats

We evaluated the impacts of maternal consumption of different types of fatty acids during pregnancy and lactation on the lipid and glucose metabolism of 21-day-old offspring. Rats received either control (C), saturated (SFAs), trans (TFAs) or n - 3 polyunsaturated (PUFAs) normolipidic diets throughout pregnancy and lactation. 21-day old male pups constituted the groups: C21, S21, T21 and PUFA21. At 21st day, serum parameters, hepatic triacylglycerol (TAG) deposition, oral glucose tolerance test (OGTT) and liver protein expressions were investigated. We found a decrease in serum concentrations of TAG, total cholesterol and FFA as well as in hepatic TAG content and baseline glycaemia, accompanied by an increase in catalase expression in PUFA21 group. In T21 group, OGTT showed slight disturbance in glucose homeostasis. Summarily, while early exposure to TFAs-based diets seems to harm pups' glucose homeostasis, maternal consumption of n - 3 PUFAs can improve lipid metabolism, TAG hepatic accumulation and catalase protein expression in 21-day-old offspring.

Targeting Oxidative Stress and Mitochondrial Dysfunction in the Treatment of Impaired Wound Healing: A Systematic Review

Wound healing is a well-tuned biological process, which is achieved via consecutive and overlapping phases including hemostasis, inflammatory-related events, cell proliferation and tissue remodeling. Several factors can impair wound healing such as oxygenation defects, aging, and stress as well as deleterious health conditions such as infection, diabetes, alcohol overuse, smoking and impaired nutritional status. Growing evidence suggests that reactive oxygen species (ROS) are crucial regulators of several phases of healing processes. ROS are centrally involved in all wound healing processes as low concentrations of ROS generation are required for the fight against invading microorganisms and cell survival signaling. Excessive production of ROS or impaired ROS detoxification causes oxidative damage, which is the main cause of non-healing chronic wounds. In this context, experimental and clinical studies have revealed that antioxidant and anti-inflammatory strategies have proven beneficial in the non-healing state. Among available antioxidant strategies, treatments using mitochondrial-targeted antioxidants are of particular interest. Specifically, mitochondrial-targeted peptides such as elamipretide have the potential to mitigate mitochondrial dysfunction and aberrant inflammatory response through activation of nucleotide-binding oligomerization domain (NOD)-like family receptors, such as the pyrin domain containing 3 (NLRP3) inflammasome, nuclear factor-kappa B (NF-κB) signaling pathway inhibition, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2).

Glutathione S-transferase genes and the risk of type 2 diabetes mellitus: Role of sexual dimorphism, gene-gene and gene-smoking interactions in disease susceptibility

BACKGROUND

Compromised defense against reactive oxygen species (ROS) is considered important in the pathogenesis of type 2 diabetes mellitus (T2DM); therefore, genes encoding antioxidant defense enzymes may contribute to disease susceptibility. This study investigated whether polymorphisms in genes encoding glutathione S-transferase M1 (GSTM1), T1 (GSTT1), and P1 (GSTP1) jointly contribute to the risk of T2DM.

METHODS

In all, 1120 unrelated Russian subjects (600 T2DM patients, 520 age- and sex-matched healthy subjects), were recruited to the study. Genotyping was performed by multiplex polymerase chain reaction (PCR; del/del polymorphisms of GSTM1 and GSTT1) and TaqMan-based PCR (polymorphisms I105V and A114V of GSTP1). Plasma ROS and glutathione levels in study subjects were analyzed by fluorometric and colorimetric assays, respectively.

RESULTS

Genotype del/del GSTT1 was significantly associated with the risk of T2DM (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.17-2.21, P = 0.003). Gender-stratified analysis showed that the deletion genotypes of GSTM1 (OR 1.99, 95% CI 1.30-3.05; P = 0.0002, Q = 0.016) and GSTT1 (OR 2.23, 95% CI 1.22-4.09; P = 0.008, Q = 0.0216), as well as genotype 114A/V of GSTP1 (OR 2.85, 95% CI 1.44-5.62; P = 0.005, Q = 0.02) were associated with an increased risk of T2DM exclusively in males. Three genotype combinations (i.e. GSTM1+ × GSTT1+, GSTM1+ × GSTP1 114A/A and GSTT1+ × GSTP1 114A/A) showed significant associations with a decreased risk of T2DM in males.

CONCLUSIONS

This study demonstrates, for the first time, that genes encoding glutathione S-transferases jointly contribute to the risk of T2DM, and that their effects on disease susceptibility are gender specific.

The relationship between MnSOD Val16Ala gene polymorphism and the level of serum total antioxidant capacity with the risk of chronic kidney disease in type 2 diabetic patients: a nested case-control study in the Tehran lipid glucose study

Background

Several studies have shown significant associations between manganese superoxide dismutase (MnSOD) Val16Ala polymorphism and diabetic complications, but this association has not been explored in relation with chronic kidney disease (CKD) in Type 2 diabetes mellitus (T2DM) patients. Total antioxidant capacity (TAC) level changes in diabetic condition and may play important role in onset or progression of the disease and its complications. The present study investigated the association of MnSOD Val16Ala polymorphism and serum TAC with the risk of CKD in T2DM patients.

Methods

This nested case-control study included 280 type 2 diabetic patients with CKD and 280 age, sex and diabetes duration-matched control subjects selected from the participants of the Tehran Lipid and Glucose Study. MnSOD val16Ala (rs4880) SNP was genotyped by the Tetra-Primer ARMS-polymerase chain reaction analysis. Serum TAC was measured using ferric-reducing antioxidant power assay. Statistical analysis was performed using STATA statistical package v.12.0 or SPSS (Version 22.0).

Results

The Ala allele of the MnSOD Val16Ala polymorphism was associated with a lower risk of CKD (odds ratio (OR), 0.55; 95% confidence interval (CI), 0.36–0.84; P = 0.006). Median serum TAC in CKD group was 920 μmol/L and was significantly lower (p < 0.001) compared to the control group (1045 μmol/L). Using an adjusted conditional logistic regression, we didn’t observe any significant interaction between MnSOD Val16Ala SNP with quartiles of serum TAC in relation to CKD.

Conclusion

A significant association was found between the MnSOD Val16Ala polymorphism and CKD, but this association is not affected by serum TAC level in T2DM patients.

Sensing Technologies for Detection of Acetone in Human Breath for Diabetes Diagnosis and Monitoring

The review describes the technologies used in the field of breath analysis to diagnose and monitor diabetes mellitus. Currently the diagnosis and monitoring of blood glucose and ketone bodies that are used in clinical studies involve the use of blood tests. This method entails pricking fingers for a drop of blood and placing a drop on a sensitive area of a strip which is pre-inserted into an electronic reading instrument. Furthermore, it is painful, invasive and expensive, and can be unsafe if proper handling is not undertaken. Human breath analysis offers a non-invasive and rapid method for detecting various volatile organic compounds thatare indicators for different diseases. In patients with diabetes mellitus, the body produces excess amounts of ketones such as acetoacetate, beta-hydroxybutyrate and acetone. Acetone is exhaled during respiration. The production of acetone is a result of the body metabolising fats instead of glucose to produce energy. There are various techniques that are used to analyse exhaled breath including Gas Chromatography Mass Spectrometry (GC-MS), Proton Transfer Reaction Mass Spectrometry (PTR-MS), Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS), laser photoacoustic spectrometry and so on. All these techniques are not portable, therefore this review places emphasis on how nanotechnology, through semiconductor sensing nanomaterials, has the potential to help individuals living with diabetes mellitus monitor their disease with cheap and portable devices.