The Role of Oxidative Stress in the Development of Diabetes Mellitus and Its Complications

Antioxidant and anti-inflammatory effects of Boswellia dalzielii and Hibiscus sabdariffa extracts in alloxan-induced diabetic rats

Diabetes mellitus (DM) is one of the leading worldwide public health problems. It is characterized by hyperglycemia which induces oxidative stress and inflammation, both involved in the pathogenesis of diabetes. We previously showed that Boswellia dalzielii (BD) and Hibiscus sabdariffa (HS) extracts reduced hyperglycemia and hyperlipidemia in alloxan-induced diabetic rats. In the present study, we evaluated the antioxidant and anti-inflammatory activities of both plants in alloxan-induced diabetic rats. Two sets of experiments were conducted in male Wistar rats subjected to a single intraperitoneal injection of alloxan monohydrate (150 mg/kg, b. w.). Then, diabetic rats were daily administered with either BD (1st set of experiments) or HS (2nd set of experiments) at 100, 200, and 400 mg/kg orally for 21 consecutive days. Glibenclamide (10 mg/kg) was also administered as a reference drug. At the end of the study, the animals were anesthetized, and blood samples were collected from each animal. Then, oxidative stress and inflammatory biomarkers in the serum were determined. We found that treatment with BD and HS significantly reduced malondialdehyde (MDA) and enhanced the levels of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). These extracts also significantly decreased the inflammatory markers tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). From the results obtained, it can therefore be concluded that BD and HS have the potential to being developed as natural sources of antioxidant and anti-inflammatory agents that can be used for the prevention or treatment of DM.

Research progress on and molecular mechanism of vacuum sealing drainage in the treatment of diabetic foot ulcers

Diabetic foot ulcers (DFUs) are common chronic wounds and a common complication of diabetes. The foot is the main site of diabetic ulcers, which involve small and medium-sized arteries, peripheral nerves, and microcirculation, among others. DFUs are prone to coinfections and affect many diabetic patients. In recent years, interdisciplinary research combining medicine and material science has been increasing and has achieved significant clinical therapeutic effects, and the application of vacuum sealing drainage (VSD) in the treatment of DFUs is a typical representative of this progress, but the mechanism of action remains unclear. In this review, we integrated bioinformatics and literature and found that ferroptosis is an important signaling pathway through which VSD promotes the healing of DFUs and that System Xc-GSH-GPX4 and NAD(P)H-CoQ10-FSP1 are important axes in this signaling pathway, and we speculate that VSD is most likely to inhibit ferroptosis to promote DFU healing through the above axes. In addition, we found that some classical pathways, such as the TNF, NF-κB, and Wnt/β-catenin pathways, are also involved in the VSD-mediated promotion of DFU healing. We also compiled and reviewed the progress from clinical studies on VSD, and this information provides a reference for the study of VSD in the treatment of DFUs.

Post-Hypoglycemic hyperglycemia are highly relevant markers for stratification of glycemic variability and partial remission status of pediatric patients with new-onset type 1 diabetes

AIMS

To evaluate whether parameters of post-hypoglycemic hyperglycemia (PHH) correlated with glucose homeostasis during the first year after type 1 diabetes onset and helped to distinguish pediatric patients undergoing partial remission or not.

METHODS

In the GLUREDIA (GLUcagon Response to hypoglycemia in children and adolescents with new-onset type 1 DIAbetes) study, longitudinal values of clinical parameters, continuous glucose monitoring metrics and residual β-cell secretion from children with new-onset type 1 diabetes were analyzed during the first year after disease onset. PHH parameters were calculated using an in-house algorithm. Correlations between PHH parameters (i.e., PHH frequency, PHH duration, PHH area under the curve [PHHAUC]) and glycemic homeostasis markers were studied using adjusted mixed-effects models.

RESULTS

PHH parameters were strong markers to differentiate remitters from non-remitters with PHH/Hyperglycemia duration ratio being the most sensitive (ratio<0.02; sensitivity = 86% and specificity = 68%). PHHAUC moderately correlated with parameters of glucose homeostasis including TIR (R2 = 0.35, p-value < 0.05), coefficient of variation (R2 = 0.22, p-value < 0.05) and Insulin-Dose Adjusted A1c (IDAA1C) (R2 = 0.32, p-value < 0.05) and with residual β-cell secretion (R2 = 0.17, p-value < 0.05). Classification of patients into four previously described glucotypes independently validated PHH parameters as reliable markers of glucose homeostasis and improved the segregation of patients with intermediate values of IDAA1C and estimated C-peptide (CPEPEST). Finally, a combination of PHH parameters identified groups of patients with specific patterns of hypoglycemia.

CONCLUSION

PHH parameters are new minimal-invasive markers to discriminate remitters from non-remitters and evaluate glycemic homeostasis during the first year of type 1 diabetes. PHH parameters may also allow patient-targeted therapeutic management of hypoglycemic episodes.

Advance in the pharmacological effects of quercetin in modulating oxidative stress and inflammation related disorders

Numerous pharmacological effects of quercetin have been illustrated, including antiinflammation, antioxidation, and anticancer properties. In recent years, the antioxidant activity of quercetin has been extensively reported, in particular, its impacts on glutathione, enzyme activity, signaling transduction pathways, and reactive oxygen species (ROS). Quercetin has also been demonstrated to exert a striking antiinflammatory effect mainly by inhibiting the production of cytokines, reducing the expression of cyclooxygenase and lipoxygenase, and preserving the integrity of mast cells. By regulating oxidative stress and inflammation, which are regarded as two critical processes involved in the defense and regular physiological operation of biological systems, quercetin has been validated to be effective in treating a variety of disorders. Symptoms of these reactions have been linked to degenerative processes and metabolic disorders, including metabolic syndrome, cardiovascular, neurodegeneration, cancer, and nonalcoholic fatty liver disease. Despite that evidence demonstrates that antioxidants are employed to prevent excessive oxidative and inflammatory processes, there are still concerns regarding the expense, accessibility, and side effects of agents. Notably, natural products, especially those derived from plants, are widely accessible, affordable, and generally safe. In this review, the antioxidant and antiinflammatory abilities of the active ingredient quercetin and its application in oxidative stress-related disorders have been outlined in detail.

New Insights into the Role of Oxidative Stress in the Development of Diabetes Mellitus and Its Complications

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Polysaccharides from natural resource: ameliorate type 2 diabetes mellitus via regulation of oxidative stress network

Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia that can occur in children, adults, elderly people, and pregnant women. Oxidative stress is a significant adverse factor in the pathogenesis of DM, especially type 2 diabetes mellitus (T2DM), and metabolic syndrome. Natural polysaccharides are macromolecular compounds widely distributed in nature. Some polysaccharides derived from edible plants and microorganisms were reported as early as 10 years ago. However, the structural characterization of polysaccharides and their therapeutic mechanisms in diabetes are relatively shallow, limiting the application of polysaccharides. With further research, more natural polysaccharides have been reported to have antioxidant activity and therapeutic effects in diabetes, including plant polysaccharides, microbial polysaccharides, and polysaccharides from marine organisms and animals. Therefore, this paper summarizes the natural polysaccharides that have therapeutic potential for diabetes in the past 5 years, elucidating their pharmacological mechanisms and identified primary structures. It is expected to provide some reference for the application of polysaccharides, and provide a valuable resource for the development of new diabetic drugs.

Diagnostic values of ischemia modified albumin in diabetes-related complications: a narrative review

Purpose

Oxidative stress (OS) plays a critical role in the onset and progression of macro and microvascular complications of diabetes mellitus (DM). Ischemia-modified albumin (IMA) is a novel and simple test for evaluating OS. In the present study, we reviewed the available information on the alteration of circulating IMA in DM and its possible prognostic and diagnostic value in DM-related complications.

Methods

Relevant studies regarding IMA alteration in DM published until May 30, 2022 were extracted from Google Scholar, PubMed, Scopus, and Science Direct databases. The following key words were used: IMA, DM, diabetes complications, retinopathy, nephropathy, diabetic foot, and vascular complications.

Results

This review revealed increased circulating IMA levels in the patients with type 1, type 2, and gestational DM. Furthermore, IMA showed a close relationship with the severity of DM complications including hyperglycemia, dyslipidemia, diabetic retinopathy, diabetic nephropathy, peripheral arterial disease, and diabetic foot ulcer. However, lack of assay standardization and low specificity are major obstacles to the use of IMA as a promising biomarker.

Conclusion

IMA levels are associated with DM complications and can be applied as a practical test for evaluating the risk and predicting the severity of DM complications.

The association between dietary acrylamide intake and the risk of type 2 diabetes incidence in the Tehran lipid and glucose study

This study aimed at investigating the association of acrylamide consumption with the incidence of type 2 diabetes (T2D) in adults. The 6022 subjects of the Tehran lipid and glucose study participants were selected. The acrylamide content of food items were summed and computed cumulatively across follow up surveys. Multivariable Cox proportional hazard regression analyses were performed to estimate the hazards ratio (HR) and 95% confidence interval (CI) of incident T2D. This study was done on men and women, respectively aged 41.5 ± 14.1 and 39.2 ± 13.0 years. The mean ± SD of dietary acrylamide intake was 57.0 ± 46.8 µg/day. Acrylamide intake was not associated with the incidence of T2D after adjusting for confounding variables. In women, a higher acrylamide intake was positively associated with T2D [HR (CI) for Q4: 1.13 (1.01-1.27), P trend: 0.03] after adjusting for confounding factors. Our results demonstrated that dietary intake of acrylamide was associated with an increased risk of T2D in women.

Therapeutic role of growth factors in treating diabetic wound

Wounds in diabetic patients, especially diabetic foot ulcers, are more difficult to heal compared with normal wounds and can easily deteriorate, leading to amputation. Common treatments cannot heal diabetic wounds or control their many complications. Growth factors are found to play important roles in regulating complex diabetic wound healing. Different growth factors such as transforming growth factor beta 1, insulin-like growth factor, and vascular endothelial growth factor play different roles in diabetic wound healing. This implies that a therapeutic modality modulating different growth factors to suit wound healing can significantly improve the treatment of diabetic wounds. Further, some current treatments have been shown to promote the healing of diabetic wounds by modulating specific growth factors. The purpose of this study was to discuss the role played by each growth factor in therapeutic approaches so as to stimulate further therapeutic thinking.

Pharmacological and mechanistic study of PS1, a Pdia4 inhibitor, in β-cell pathogenesis and diabetes in db/db mice

Pdia4 has been characterized as a key protein that positively regulates β-cell failure and diabetes via ROS regulation. Here, we investigated the function and mechanism of PS1, a Pdia4 inhibitor, in β-cells and diabetes. We found that PS1 had an IC₅₀ of 4 μM for Pdia4. Furthermore, PS1 alone and in combination with metformin significantly reversed diabetes in db/db mice, 6 to 7 mice per group, as evidenced by blood glucose, glycosylated hemoglobin A1c (Hb_A1c), glucose tolerance test, diabetic incidence, survival and longevity (P < 0.05 or less). Accordingly, PS1 reduced cell death and dysfunction in the pancreatic β-islets of db/db mice as exemplified by serum insulin, serum c-peptide, reactive oxygen species (ROS), islet atrophy, and homeostatic model assessment (HOMA) indices (P < 0.05 or less). Moreover, PS1 decreased cell death in the β-islets of db/db mice. Mechanistic studies showed that PS1 significantly increased cell survival and insulin secretion in Min6 cells in response to high glucose (P < 0.05 or less). This increase could be attributed to a reduction in ROS production and the activity of electron transport chain complex 1 (ETC C1) and Nox in Min6 cells by PS1. Further, we found that PS1 inhibited the enzymatic activity of Pdia4 and mitigated the interaction between Pdia4 and Ndufs3 or p22 in Min6 cells (P < 0.01 or less). Taken together, this work demonstrates that PS1 negatively regulated β-cell pathogenesis and diabetes via reduction of ROS production involving the Pdia4/Ndufs3 and Pdia4/p22 cascades.

Identification and Quantification of Bioactive Compounds in Organic and Conventional Edible Pansy Flowers (Viola × wittrockiana) and Their Antioxidant Activity

The use of edible flowers has become increasingly popular as a good source of bioactive compounds. Many flowers can be consumed, but there is a lack of information about the chemical composition of organic and conventional flowers. Organic crops represent a higher level of food safety because pesticides and artificial fertilizers are prohibited. The present experiment was carried out with organic and conventional edible pansy flowers of different colors: double-pigmented violet/yellow and single-pigmented yellow flowers. In fresh flowers, the contents of dry matter and polyphenols (including phenolic acids, flavonoids, anthocyanins, carotenoids, and chlorophylls) and the antioxidant activity were determined by the HPLC-DAD method. The results showed that organic edible pansy flowers contained significantly more bioactive compounds, especially polyphenols (333.8 mg/100 g F.W.), phenolic acids (40.1 mg/100 g F.W.), and anthocyanins (293.7 mg/100 g F.W.) compared to conventional methods. Double-pigmented (violet/yellow) pansy flowers are more recommended for the daily diet than single-pigmented yellow flowers. The results are unique and open the first chapter in a book on the nutritional value of organic and conventional edible flowers.

Kitul, a food plant with antidiabetic-like effects: Reduction of intracellular reactive species in glucose-stimulated RIN-5F pancreatic β-cells and mitigation of pro-inflammatory mediators in activated RAW 264.7 macrophages

Kitul (Caryota urens L.) inflorescences are broadly used for sweet sap production in Asian countries and Kitul food products are known as being suitable for diabetic patients. Considering the strong ability to inhibit α-glucosidase, we hypothesize that kitul antidiabetic properties might also involve the modulation of inflammatory pathways and hyperglycaemia-induced oxidative damage. Hence, the effects of an inflorescence's methanol extract were investigated in glucose-stimulated pancreatic cells (RIN-5F) and LPS-stimulated RAW 264.7 macrophages. The extract reduced the overproduction of intracellular reactive species in pancreatic cells and also NO, L-citrulline and IL-6 levels in LPS-stimulated RAW 264.7 macrophages. Inhibition of 5-lipoxygenase (IC₅₀ = 166.1 µg/mL) through an uncompetitive manner was also recorded upon treatment with C. urens inflorescences extract. The phenolic profile of the inflorescences was characterized by HPLC-DAD, six hydroxycinnamic acids being identified and quantified. Overall, our data provide additional evidence on the pleiotropic mechanisms of Kitul inflorescences as an antidiabetic agent.

An investigation into the potential action of polyphenols against human Islet Amyloid Polypeptide aggregation in type 2 diabetes

Type 2 diabetes (T2D), a chronic metabolic disease characterized by hyperglycemia, results in significant disease burden and financial costs globally. Whilst the majority of T2D cases seem to have a genetic basis, non-genetic modifiable and non-modifiable risk factors for T2D include obesity, diet, physical activity and lifestyle, smoking, age, ethnicity, and mental stress. In healthy individuals, insulin secretion from pancreatic islet β-cells is responsible for keeping blood glucose levels within normal ranges. T2D patients suffer from multifactorial onset of β-cell dysfunction and/or loss of β-cell mass owing to reactive oxygen species (ROS) production, mitochondrial dysfunction, autophagy, and endoplasmic reticulum (ER) stress. Most predominantly however, and the focus of this review, it is the aggregation and misfolding of human Islet Amyloid Polypeptide (hIAPP, also known as amylin), which is detrimental to β-cell function and health. Whilst hIAPP is found in healthy individuals, its misfolded version is cytotoxic and able to induce β-cell dysfunction and/or death through various mechanisms including membrane changes in β-cell causing influx of calcium ions, arresting complete granule membrane recovery and ER stress. There are several existing therapeutics for T2D. However, there is a need for alternative or adjunct therapies for T2D with milder adverse effects and greater availability. Foremost among the potential natural therapeutics are polyphenols. Extensive data from studies evaluating the potential of polyphenols to inhibit hIAPP aggregation and disassemble aggregated hIAPP are promising. Moreover, in-vivo, and in-silico studies also highlight the potential effects of polyphenols against hIAPP aggregation and mitigation of larger pathological effects of T2D. Whilst there have been some promising clinical studies on the therapeutic potential of polyphenols, extensive further clinical studies and in-vitro studies evaluating the mechanisms of action and ideal doses for many of these compounds are required. The need for these studies is made more important by the postulated link between Alzheimer's disease (AD) and T2D pathophysiology given the similar aggregation process of their respective amyloid proteins, which evokes thoughts of cross-reactive polyphenols which can be effective for both AD and T2D patients.

Specific Nanodrug for Diabetic Chronic Wounds Based on Antioxidase-Mimicking MOF-818 Nanozymes

Chronic wound is a common complication for diabetic patients, which entails substantial inconvenience, persistent pain, and significant economic burden to patients. However, current clinical treatments for diabetic chronic wounds remain unsatisfactory. A prolonged but ineffective inflammation phase in chronic wounds is the primary difference between diabetic chronic wounds and normal wounds. Herein, we present an effective antioxidative system (MOF/Gel) for chronic wound healing of diabetic rats through integrating a metal organic framework (MOF) nanozyme with antioxidant enzyme-like activity with a hydrogel (Gel). MOF/Gel can continuously scavenge reactive oxygen species to modulate the oxidative stress microenvironment in diabetic chronic wounds, which leads to a natural transition from the inflammation phase to the proliferation phase. Impressively, the efficacy of one-time-applied MOF/Gel was comparable to that of the human epidermal growth factor Gel, a widely used clinical drug for various wound treatments. Such an effective, safe, and convenient MOF/Gel system can meet complex clinical demands.

Effects of edaravone on oxidative protein modification and activity of gelatinases after intracerebral hemorrhage in rats with nicotinamide-streptozotocin induced diabetes

Stroke, especially hemorrhagic form, is one of the most serious comorbidity disease of diabetes mellitus, often associated with high mortality, particularly in type 2 DM (T2DM). Therefore, it is relevant the search for drugs with a metabolically justified protective effect. Edaravone (Eda) is widely used for treating ischemic stroke but its biochemical effects in intracerebral hemorrhage (ICH) associated with T2DM is not still confirmed. The aim of the study was to assess the impact of Eda on the markers of oxidative modification of proteins (OMP), such as advanced oxidation protein products (AOPP), neutral and basic carbonyls (PC370 and PC430), advanced glycation end products (AGE) and ischemia modified albumin (IMA) as well as on the activity of matrix metalloproteinases MMP2/MMP9 (gelatinases) in rats with experimental T2DM after collagenase-induced ICH. Metformin was used as a comparative drug. The data obtained indicate that ICH in diabetic rats is accompanied by an increase in AOPP, PC370, AGE, and mature forms of both gelatinases. On the contrary, IMA and proMMP9 were below normal level after ICH. Both studied drugs decreased the OMP markers to the levels of intact rats or lower, and Eda show a more potent effect. Besides, Eda significantly decreased the activity of MMP9 and changed progelatinases activity. We conclude that Eda has a perspective to be useful in the treatment of comorbid brain hemorrhage in T2DM due to inhibiting of oxidative stress and modulation of gelatinases activity.

Evaluation of tenofovir disoproxil fumarate loaded silver nanoparticle on testicular morphology in experimental type-2 diabetic rats

Reproductive derangement and metabolic disorders in human immunodeficiency virus (HIV) infected persons require a nanoparticle delivery system to convey antiretroviral drugs to the anatomical sanctuary such as testis. This study investigated the effects of tenofovir disoproxil fumarate (TDF) loaded silver nanoparticles (AgNPs) on the testicular oxidative stress, inflammatory cytokines and histology in male diabetic rats. Thirty-six Sprague-Dawley rats weighing 230 ± 20 g were randomly divided into diabetic and non-diabetic groups (n = 18). Diabetes was induced using the fructose-streptozotocin (Frt-STZ) rat model. Both groups were further divided into three (n = 6) and administered distilled water, TDF, or TDF-AgNP. Results obtained with the TDF-AgNP administration showed a significant increase (p < .05) in the reduced glutathione and catalase levels. Tumour necrosis factor-alpha and interleukin 6 were reduced in diabetic rats administered TDF-AgNP. More so, administration of TDF-AgNP to diabetic rats improved testicular histoarchitecture in diabetic rats. In addition, diabetic rats administered TDF-AgNP showed a significant reduction (p < .05) in blood glucose levels. TDF-AgNP to diabetic rats enhanced testicular antioxidant enzyme, reduced testicular inflammation, and alleviated structural derangements in the testis. Thus, the application of AgNP to deliver TDF may alleviate testicular toxicity and subsequently cater for neglected reproductive dysfunction during the management of HIV infection.

Impairment of insulin signaling pathway PI3K/Akt/mTOR and insulin resistance induced AGEs on diabetes mellitus and neurodegenerative diseases: a perspective review

Insulin resistance is common in type 2 diabetes mellitus (T2DM), neurodegenerative diseases, cardiovascular diseases, kidney diseases, and polycystic ovary syndrome. Impairment in insulin signaling pathways, such as the PI3K/Akt/mTOR pathway, would lead to insulin resistance. It might induce the synthesis and deposition of advanced glycation end products (AGEs), reactive oxygen species, and reactive nitrogen species, resulting in stress, protein misfolding, protein accumulation, mitochondrial dysfunction, reticulum function, and metabolic syndrome dysregulation, inflammation, and apoptosis. It plays a huge role in various neurodegenerative diseases like Parkinson's disease, Alzheimer's disease, Huntington's disease, and Amyloid lateral sclerosis. In this review, we intend to focus on the possible effect of insulin resistance in the progression of neurodegeneration via the impaired P13K/Akt/mTOR signaling pathway, AGEs, and receptors for AGEs.

Heme Oxygenase-1 as Therapeutic Target for Diabetic Foot Ulcers

A diabetic foot ulcer (DFU) is one of the major complications of diabetes. Wound healing under diabetic conditions is often impaired. This is in part due to the excessive oxidative stress, prolonged inflammation, immune cell dysfunction, delayed re-epithelialization, and decreased angiogenesis present at the wound site. As a result of these multifactorial impaired healing pathways, it has been difficult to develop effective therapeutic strategies for DFU. Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in heme degradation generating carbon monoxide (CO), biliverdin (BV) which is converted into bilirubin (BR), and iron. HO-1 is a potent antioxidant. It can act as an anti-inflammatory, proliferative, angiogenic and cytoprotective enzyme. Due to its biological functions, HO-1 plays a very important role in wound healing, in part mediated through the biologically active end products generated by its enzymatic activity, particularly CO, BV, and BR. Therapeutic strategies involving the activation of HO-1, or the topical application of its biologically active end products are important in diabetic wound healing. Therefore, HO-1 is an attractive therapeutic target for DFU treatment. This review will provide an overview and discussion of the importance of HO-1 as a therapeutic target for diabetic wound healing.

Haskap Berry Leaves (Lonicera caerulea L.)—The Favorable Potential of Medical Use

The presented research evaluates the medical use potential of Lonicera caerulea leaves, which are waste plants in cultivating berries. The study’s screening activity included the leaves of five varieties of Lonicera caerulea: Atut, Duet, Wojtek, Zojka, and Jugana. The microbiological analysis confirmed the safety of using Lonicera caerulea leaves without significant stabilization. Lonicera caerulea leaves standardization was carried out based on the results of the chromatographic analysis, and it showed differences in the contents of active compounds (loganic, chlorogenic and caffeic acids, and rutin), which are attributed to biological activity. For the Lonicera caerulea leaves varieties tested, the differences in the content of total polyphenol content, chlorophylls, and carotenoids were also confirmed. The screening of biological activity of five Lonicera caerulea leaf varieties was carried out concerning the possibility of inhibiting the activity of α-glucosidase, lipase, and hyaluronidase as well, and the antioxidant potential was determined. The defined profile of the biological activity of Lonicera caerulea leaves makes it possible to indicate this raw material as an essential material supporting the prevention and treatment of type II diabetes. However, this research showed that tested enzymes were strongly inhibited by the variety Jugana. The health-promoting potential of Lonicera caerulea leaves was correlated with the highest chlorogenic acid and rutin content in the variety Jugana.

The Relationship between Selected Inflammation and Oxidative Stress Biomarkers and Carotid Intima-Media Thickness (IMT) Value in Youth with Type 1 Diabetes Co-Existing with Early Microvascular Complications

Recent years have confirmed the importance of oxidative stress and biomarkers of inflammation in estimating the risk of cardiovascular disease (CVD) and explaining not fully understood pathogenesis of diabetic macroangiopathy. We aimed to analyze the relation between the intima-media thickness (IMT) of common carotid arteries and the occurrence of classical cardiovascular risk factors, together with the newly proposed biomarkers of CVD risk (high-sensitivity C-reactive protein (hsCRP), myeloperoxidase (MPO), adiponectin, N-terminal-pro B-type natriuretic peptide (NT-proBNP) and vitamin D) in youth with type 1 diabetes (T1D) recognized in screening tests to present early stages of microvascular complications (VC). The study group consisted of 50 adolescents and young adults with T1D, mean age 17.1 years (10–26 age range), including 20 patients with VC (+) and 30 VC (−). The control group (Control) consisted of 22 healthy volunteers, mean age 16.5 years (11–26 age range). In the VC (+) patients, we found a significantly higher concentration of HbA1c, lipid levels, hsCRP and NT-proBNP. BMI and blood pressure values were highest in the VC (+) group. Higher levels of MPO and lower levels of vitamin D were found in both diabetic groups vs. Control. IMT in VC (+) patients was significantly higher and correlated positively with HbA1c, hsCRP, NT-pro-BNP and negatively with vitamin D levels. In conclusion, youth with T1D and VC (+) present many abnormalities in the classical and new CVD biomarkers. hsCRP and MPO seem to be the most important markers for estimating the risk of macroangiopathy. NT-proBNP may present a possible marker of early myocardial injury in this population.

Proteomics reveal the protective effects of chlorogenic acid on Enterococcus faecium Q233 in a simulated pro-oxidant colonic environment

Certain phytochemicals have been found to promote the beneficial effects of probiotic bacteria although the molecular mechanisms of such interactions are poorly understood. The objective of the present study was to evaluate the impact of the exposure to 0.5 mM chlorogenic acid (CA) on the redox status and proteome of Enterococcus faecium isolated from cheese and challenged with 2.5 mM hydrogen peroxide (H₂O₂). The bacterium was incubated in anaerobic conditions for 48 h at 37 °C. CA exposure led to a more intense oxidative stress and accretion of bacterial protein carbonyls than those induced by H₂O₂. The oxidative damage to bacterial proteins was even more severe in the bacterium treated with both CA and H₂O₂, yet, such combination led to a strengthening of the antioxidant defenses, namely, a catalase-like activity. The proteomic study indicated that H₂O₂ caused a decrease in energy supply and the bacterium responded by reinforcing the membrane and wall structures and counteracting the redox and pH imbalance. CA stimulated the accretion of proteins related to translation and transcription regulators, and hydrolases. This phytochemical was able to counteract certain proteomic changes induced by H₂O₂ (i.e. increase of ATP binding cassete (ABC) transporter complex) and cause the increase of Rex, a redox-sensitive protein implicated in controlling metabolism and responses to oxidative stress. Although this protection should be confirmed under in vivo conditions, such effects point to benefits in animals or humans affected by disorders in which oxidative stress plays a major role.

Protein oxidation marker, α-amino adipic acid, impairs proteome of differentiated human enterocytes: Underlying toxicological mechanisms

Protein oxidation and oxidative stress are involved in a variety of health disorders such as colorectal adenomas, inflammatory bowel's disease, neurological disorders and aging, among others. In particular, the specific final oxidation product from lysine, the α-amino adipic acid (α-AA), has been found in processed meat products and emphasized as a reliable marker of type II diabetes and obesity. Currently, the underlying mechanisms of the biological impairments caused by α-AA are unknown. To elucidate the molecular basis of the toxicological effect of α-AA, differentiated human enterocytes were exposed to dietary concentrations of α-AA (200 μM) and analyzed by flow cytometry, protein oxidation and proteomics using a Nanoliquid Chromatography-Orbitrap MS/MS. Cell viability was significantly affected by α-AA (p < 0.05). The proteomic study revealed that α-AA was able to alter cell homeostasis through impairment of the Na⁺/K⁺-ATPase pump, energetic metabolism, and antioxidant response, among other biological processes. These results show the importance of dietary oxidized amino acids in intestinal cell physiology and open the door to further studies to reveal the impact of protein oxidation products in pathological conditions.

Evaluation of Antioxidant Therapeutic Value of ACE Inhibitor as Adjunct Therapy on Type 2 Diabetes Mellitus Patients with Cardiovascular Disease

Diabetes mellitus (DM) is believed to promote oxidative stress, which potentially provokes and accelerates complications in conditions such as atherosclerotic cardiovascular, peripheral arterial, and cerebrovascular diseases. In this study, we evaluated the antioxidant therapeutic value of adding an angiotensin-converting enzyme (ACE) inhibitor-a low dose of captopril-as adjunct therapy to the treatment regimen of Type 2 diabetes mellitus (T2DM). Participants were distributed among two different groups: control and treated. T2DM patients in the treated group (group 2) were given a supplement of the ACE inhibitor capotopril, 12.5 mg/day, in addition to standard treatment. All subjects were interviewed for clinical examination. All patients in group 2 were re-examined monthly for 3 months to evaluate FBS, HbA1c, MDA, total GSH, reduced GSH, GSSG, and ox-LDL. All parameters were repeated for patients in group 2 after 1 and 3 months. The study showed improvements in the glycemic and oxidative stress status with the addition of a low dose of captopril-not very prominent but statistically significant. Reduced GSH decreased by 73.6% (P = 0.016) and the TBARS level was decreased by 58.3% (P = 0.018) after 3 months of treatment, while ox-LDL was decreased by 26.4% (P = 0.036) at the end of treatment. In summary, the clinical improvements in the disease indices toward normal levels make the use of low doses of ACE inhibitors as adjunct therapy in T2DM worth pursuing. Thus, investigations directed at preventing or protecting against oxidative damage may open a new window for treatment of diabetes mellitus.

Etlingera elatior Flower Aqueous Extract Protects against Oxidative Stress-Induced Nephropathy in a Rat Model of Type 2 Diabetes

Diabetes mellitus (DM) is a known systemic disease with increasing global prevalence and multi-organ complications including diabetic nephropathy (DN). The trend of using medicinal plants in the management of DM is increasing exponentially. Etlingera elatior is a medicinal plant that contains chemicals and antioxidants that delay the oxidation process. However, available data focusing on its use on DN are inconsistent and scarce. This study aims to investigate the antidiabetic and nephroprotective effects of E. elatior flower aqueous extract (EEAE) in a type 2 DM rat (T2DR) model. The T2DR model was developed using a combination of a high-fat diet (HFD) and a low dose of streptozotocin (STZ) at 35 mg/kg. Thirty-two Sprague Dawley male rats were randomly divided into four groups (n = 8): (1) control (normal rat), (2) T2DR (untreated-type 2 diabetic rat), (3) Met (250 mg/kg metformin-treated T2DR), and (4) EEAE (1000 mg/kg EEAE-treated T2DR). All treatments were administered orally for 6 weeks. EEAE significantly reduced fasting blood glucose (FBG), microalbuminuria, serum creatinine, and serum blood urea nitrogen. EEAE also reduced malondialdehyde (MDA) and enhanced the levels of antioxidant markers—superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and total antioxidant capacity (T-AOC). The inflammatory marker (interleukin (IL)-6) and fibrosis markers (transforming growth factor-beta (TGF-β), and connective tissue growth factor (CTGF)) were significantly decreased in the EEAE-treated group. The T2DR group developed DN, which was characterized by segmental sclerosis of the glomeruli associated with focal tubular atrophy and interstitial fibrosis. Interestingly, the histology of kidney tissue in the EEAE group was preserved. This effect was similar to that of the control drug metformin. In summary, the antidiabetic and nephroprotective effects might be related to the antioxidant properties and anti-inflammatory effects of the EEAE. The antidiabetic activity could be due to the presence of the active compound cyanidin-3-O-glycosides, which is an anthocyanin antioxidant, that is present in the EEAE. E. elatior has the potential to be developed as a natural source of antioxidants that can be used for the prevention or even the treatment of DM. These findings could lead to future research into the therapeutic use of E. elatior in alleviating the progression of DM and thus preventing nephropathy.

Omarigliptin alleviates cognitive dysfunction in Streptozotocin-induced diabetic mouse

Increasing epidemiological evidence supports the strong association between diabetes mellitus (DM) and cognitive dysfunction. Omarigliptin is a long-acting dipeptidyl peptidase 4 (DPP-4) inhibitor for the treatment of diabetes. However, the effect of Omarigliptin in diabetes-associated cognitive dysfunction has not been reported. In this study, we established an in vivo diabetic mice model through streptozotocin (STZ) treatment and investigated the therapeutic effect of Omarigliptin in diabetic mice. The results show that administration with Omarigliptin reduced the food and water intake of STZ-induced diabetic mice, accompanied by decreased blood glucose levels and increased serum insulin levels. The Y-Maze test demonstrated that Omarigliptin ameliorated cognitive dysfunction in STZ-induced diabetic mice. Omarigliptin presented a protective role in the brain, as shown by the decreased reactive oxygen species (ROS) level, increased NAD+/NADH ratio, adenosine triphosphate (ATP) level, and ATP synthase activity in the hippocampus. Omarigliptin induced the increased expression level of mitochondrial inner membrane protein sirtuin 3 (SIRT3) and regulated its substrates, including forkhead box O3a (FOXO3a) and superoxide dismutase 2 (SOD2). Furthermore, knockdown of SIRT3 abolished the protective effects of Omarigliptin on mitochondrial dysfunction and cognitive dysfunction in STZ-induced diabetic mice. Taken together, these findings suggest that Omarigliptin improved insulin sensitivity and cognitive function in STZ-induced diabetic mice. Mechanistically, SIRT3 expression is required for the effect of Omarigliptin. This study provided preclinical evidence that Omarigliptin has the neuroprotective effect to improve diabetes-associated cognitive dysfunction.

Reactive Oxygen Species-Mediated Diabetic Heart Disease: Mechanisms and Therapies

Significance: Diabetic heart disease (DHD) is the primary cause of mortality in people with diabetes. A significant contributor to the development of DHD is the disruption of redox balance due to reactive oxygen species (ROS) overproduction resulting from sustained high glucose levels. Therapies specifically focusing on the suppression of ROS will hugely benefit patients with DHD. Recent Advances: In addition to the gold standard pharmacological therapies, the recent development of gene therapy provides an exciting avenue for developing new therapeutics to treat ROS-mediated DHD. In particular, microRNAs (miRNAs) are gaining interest due to their crucial role in several physiological and pathological processes, including DHD. Critical Issues: miRNAs have many targets and differential function depending on the environment. Therefore, a proper understanding of the function of miRNAs in specific cell types and cell states is required for the successful application of this technology. In the present review, we first provide an overview of the role of ROS in contributing to DHD and the currently available treatments. We then discuss the newer gene therapies with a specific focus on the role of miRNAs as the causative factors and therapeutic targets to combat ROS-mediated DHD. Future Directions: The future of miRNA therapeutics in tackling ROS-mediated DHD is dependent on a complete understanding of how miRNAs behave in different cells and environments. Future research should also aim to develop conditional miRNA therapeutic platforms capable of switching on and off in response to disruptions in the redox state. Antioxid. Redox Signal. 36, 608-630.

Chimeric Agonist of Galanin Receptor GALR2 Reduces Heart Damage in Rats with Streptozotocin-Induced Diabetes

Neuropeptide galanin and its N-terminal fragments reduce the generation of reactive oxygen species and normalize metabolic and antioxidant states of myocardium in experimental cardiomyopathy and ischemia/reperfusion injury. The aim of this study was to elucidate the effect of WTLNSAGYLLGPβAH-OH (peptide G), a pharmacological agonist of the galanin receptor GalR2, on the cardiac injury induced by administration of streptozotocin (STZ) in rats. Peptide G was prepared by solid phase peptide synthesis using the Fmoc strategy and purified by preparative HPLC; its structure was confirmed by 1H-NMR spectroscopy and MALDI-TOF mass spectrometry. Experimental animals were randomly distributed into five groups: C, control; S, STZ-treated; SG10, STZ + peptide G (10 nmol/kg/day); SG50, STZ + peptide G (50 nmol/kg/day); G, peptide G (50 nmol/kg/day). Administration of peptide G prevented hyperglycemia in SG50 rats. By the end of the experiment, the ATP content, total pool of adenine nucleotides, phosphocreatine (PCr) content, and PCr/ATP ratio in the myocardium of animals of the SG50 group were significantly higher than in rats of the S group. In the SG50 and SG10 groups, the content of lactate and lactate/pyruvate ratio in the myocardium were reduced, while the glucose content was increased vs. the S group. Both doses of peptide G reduced the activation of creatine kinase-MB and lactate dehydrogenase, as well as the concentration of thiobarbituric acid reactive products in the blood plasma of STZ-treated rats to the control values. Taken together, these results suggest that peptide G has cardioprotective properties in type 1 diabetes mellitus. Possible mechanisms of peptide G action in the STZ-induced diabetes are discussed.

Green Synthesis of Silver Nanoparticles by the Cyanobacteria Synechocystis sp.: Characterization, Antimicrobial and Diabetic Wound-Healing Actions

Green nanotechnology is now accepted as an environmentally friendly and cost-effective advance with various biomedical applications. The cyanobacterium Synechocystis sp. is a unicellular spherical cyanobacterium with photo- and hetero-trophic capabilities. This study investigates the ability of this cyanobacterial species to produce silver nanoparticles (AgNPs) and the wound-healing properties of the produced nanoparticles in diabetic animals.

METHODS

UV-visible and FT-IR spectroscopy and and electron microscopy techniques investigated AgNPs' producibility by Synechocystis sp. when supplemented with silver ion source. The produced AgNPs were evaluated for their antimicrobial, anti-oxidative, anti-inflammatory, and diabetic wound healing along with their angiogenesis potential.

RESULTS

The cyanobacterium biosynthesized spherical AgNPs with a diameter range of 10 to 35 nm. The produced AgNPs exhibited wound-healing properties verified with increased contraction percentage, tensile strength and hydroxyproline level in incision diabetic wounded animals. AgNPs treatment decreased epithelialization period, amplified the wound closure percentage, and elevated collagen, hydroxyproline and hexosamine contents, which improved angiogenesis factors' contents (HIF-1α, TGF-β1 and VEGF) in excision wound models. AgNPs intensified catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities, and glutathione (GSH) and nitric oxide content and reduced malondialdehyde (MDA) level. IL-1β, IL-6, TNF-α, and NF-κB (the inflammatory mediators) were decreased with AgNPs' topical application.

CONCLUSION

Biosynthesized AgNPs via Synechocystis sp. exhibited antimicrobial, anti-oxidative, anti-inflammatory, and angiogenesis promoting effects in diabetic wounded animals.

The pathophysiology of osteoporosis in obesity and type 2 diabetes in aging women and men: The mechanisms and roles of increased bone marrow adiposity

Osteoporosis is defined as a systemic skeletal disease characterized by decreased bone mass and micro-architectural deterioration leading to increased fracture risk. Osteoporosis incidence increases with age in both post-menopausal women and aging men. Among other important contributing factors to bone fragility observed in osteoporosis, that also affect the elderly population, are metabolic disturbances observed in obesity and Type 2 Diabetes (T2D). These metabolic complications are associated with impaired bone homeostasis and a higher fracture risk. Expansion of the Bone Marrow Adipose Tissue (BMAT), at the expense of decreased bone formation, is thought to be one of the key pathogenic mechanisms underlying osteoporosis and bone fragility in obesity and T2D. Our review provides a summary of mechanisms behind increased Bone Marrow Adiposity (BMA) during aging and highlights the pre-clinical and clinical studies connecting obesity and T2D, to BMA and bone fragility in aging osteoporotic women and men.

Plukenetia conophora seed oil ameliorates streptozotocin-induced hyperglycemia and oxidative stress in rats

PURPOSE

Plukenetia conophora (African walnut) is an edible seed, widely cultivated for its ethnomedicinal and nutritional purposes. Consumption of African walnuts has been linked with blood sugar lowering effect.

OBJECTIVE

The effects of P. conophora seed oil treatment on hyperglycemia and oxidative stress were investigated in plasma, liver and kidney of streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Plukenetia conophora seed oil (PCO) was obtained by extraction of pulverized dried seed in n-hexane. Diabetes was induced by STZ injection (65 mg/kg, i.p). Rats were assigned into non-diabetic control and diabetic control (treated with vehicle), PCO (200 mg/kg) and pioglitazone (10 mg/kg). Fasting blood sugar (FBS) was taken from overnight fasted animals on day 7 and 14 respectively. Plasma, liver and kidney samples were obtained on day 14 for the determination of oxidative stress parameters malondialdehyde (MDA), reduced glutathione (GSH), catalase and superoxide dismutase (SOD).

RESULTS

PCO treatment significantly (p < 0.05) reduced STZ-induced hyperglycaemia by lowering the elevated FBS. PCO significantly reduced MDA level and attenuated STZ-induced depletion of GSH, catalase and SOD in the diabetic rats' plasma, liver and kidneys.

CONCLUSION

These results suggest that consumption of Plukenetia conophora seed might offer protection against diabetes-induced hepatic and renal damage.

Diabetes mellitus contribution to the remodeling of the tumor microenvironment in gastric cancer

Compelling pieces of evidence derived from both clinical and experimental research has demonstrated the crucial contribution of diabetes mellitus (DM) as a risk factor associated with increased cancer incidence and mortality in many human neoplasms, including gastric cancer (GC). DM is considered a systemic inflammatory disease and therefore, this inflammatory status may have profound effects on the tumor microenvironment (TME), particularly by driving many molecular mechanisms to generate a more aggressive TME. DM is an active driver in the modification of the behavior of many cell components of the TME as well as altering the mechanical properties of the extracellular matrix (ECM), leading to an increased ECM stiffening. Additionally, DM can alter many cellular signaling mechanisms and thus favoring tumor growth, invasion, and metastatic potential, as well as key elements in regulating cellular functions and cross-talks, such as the microRNAs network, the production, and cargo of exosomes, the metabolism of cell stroma and resistance to hypoxia. In the present review, we intend to highlight the mechanistic contributions of DM to the remodeling of TME in GC.

Multi-Mechanistic In Vitro Evaluation of Antihyperglycemic, Antioxidant and Antiglycation Activities of Three Phenolic-Rich Indian Red Rice Genotypes and In Silico Evaluation of Their Phenolic Metabolites

The study evaluated the antidiabetic potential of three traditional Indian red rice genotypes/RR (Kattuyanam/KA, Chennangi/CH & Karungkuruvai/KU) using a combination of in vitro, metabolomics (Quadrupole-Time of Flight-Liquid chromatography-Mass spectrometry/Q-TOF-LC-MS/MS), and in silico techniques. In terms of antihyperglycemic potential, KA exhibited the highest inhibitory activity against α-amylase; CH against α-glucosidase; and KU against DPPIV and PTP1B enzymes. KA exhibited the highest antioxidant activity (DPPH, FRAP, and ABTS) and greater inhibition of protein glycation compared to other RR indicating its potential to mitigate diabetic complications. The metabolomic analysis confirmed the presence of 99 phenolics in the sample extracts (KU-71, KA-70, CH-68). Molecular docking studies revealed seven metabolites to be good inhibitors of the four target enzymes and activators of insulin receptor substrate/IRS. The antihyperglycemic and oxidation-glycation reduction composite index revealed KA to have the highest overall antidiabetic potential. Hence, the RR could be utilized in functional foods with a multi-barrelled strategy for diabetes prevention/management.

Antioxidant and Anti-Inflammatory Activity of Cynanchum acutum L. Isolated Flavonoids Using Experimentally Induced Type 2 Diabetes Mellitus: Biological and In Silico Investigation for NF-κB Pathway/miR-146a Expression Modulation

Cynanchum acutum L. is a climbing vine that belongs to the family Apocynaceae. Using different chromatographic techniques, seven compounds were isolated from the methanolic extract of the plant. The isolated compounds include six flavonoid compounds identified as rutin (1), quercetin-3-O-neohesperidoside (2), quercetin-3-O-β-galactoside (3), isoquercitrin (4), quercetin (5), and kaempferol 3-O-β-glucoside (6), in addition to a coumarin, scopoletin (7). The structures of the compounds were elucidated based on 1D NMR spectroscopy and high-resolution mass spectrometry (HR-MS), and by comparison with data reported in the literature. The first five compounds were selected for in vivo investigation of their anti-inflammatory and antioxidant properties in a rat model of type 2 diabetes. All tested compounds significantly reduced oxidative stress and increased erythrocyte lysate levels of antioxidant enzymes, along with the amelioration of the serum levels of inflammatory markers. Upregulation of miR-146a expression and downregulation of nuclear factor kappa B (NF-κB) expression were detected in the liver and adipose tissue of rats treated with the isolated flavonoids. Results from the biological investigation and those from the validated molecular modeling approach on two biological targets of the NF-κB pathway managed to highlight the superior anti-inflammatory activity of quercetin-3-O-galactoside (3) and quercetin (5), as compared to other bioactive metabolites.

Pdia4 regulates β-cell pathogenesis in diabetes: molecular mechanism and targeted therapy

Loss of β‐cell number and function is a hallmark of diabetes. β‐cell preservation is emerging as a promising strategy to treat and reverse diabetes. Here, we first found that Pdia4 was primarily expressed in β‐cells. This expression was up‐regulated in β‐cells and blood of mice in response to excess nutrients. Ablation of Pdia4 alleviated diabetes as shown by reduced islet destruction, blood glucose and HbA1c, reactive oxygen species (ROS), and increased insulin secretion in diabetic mice. Strikingly, this ablation alone or in combination with food reduction could fully reverse diabetes. Conversely, overexpression of Pdia4 had the opposite pathophysiological outcomes in the mice. In addition, Pdia4 positively regulated β‐cell death, dysfunction, and ROS production. Mechanistic studies demonstrated that Pdia4 increased ROS content in β‐cells via its action on the pathway of Ndufs3 and p22^phox. Finally, we found that 2‐β‐D‐glucopyranosyloxy1‐hydroxytrideca 5,7,9,11‐tetrayne (GHTT), a Pdia4 inhibitor, suppressed diabetic development in diabetic mice. These findings characterize Pdia4 as a crucial regulator of β‐cell pathogenesis and diabetes, suggesting Pdia4 is a novel therapeutic and diagnostic target of diabetes.

Ceftriaxone and Melittin Synergistically Promote Wound Healing in Diabetic Rats

High glucose levels in diabetic patients are implicated in delay wound healing that could lead to more serious clinical complications. The aim of the present work was to examine the formulation of ceftriaxone (CTX) and melittin (MEL) as nanoconjugate (nanocomplex)-loaded hydroxypropyl methylcellulose (HPMC) (1.5% w/v)-based hydrogel for healing of acute wounds in diabetic rats. The CTX–MEL nanoconjugate, formulated by ion-pairing at different molar ratio, was characterized for size and zeta potential and investigated by transmission electron microscopy. CTX–MEL nanoconjugate was prepared, and its preclinical efficacy evaluated in an in vivo model of acute wound. In particular, the potential ability of the innovative CTX–MEL formulation to modulate wound closure, oxidative status, inflammatory markers, and hydroxyproline was evaluated by ELISA, while the histopathological examination was obtained by using hematoxylin and eosin or Masson’s trichrome staining techniques. Quantitative real-time PCR (qRT-PCR) of the excised tissue to measure collagen, type I, alpha 1 (Col1A1) expression and immunohistochemical assessment of vascular endothelial growth factor A (VEGF-A) and transforming growth factor beta 1 (TGF-β1) were also carried out to shed some light on the mechanism of wound healing. Our results show that the CTX–MEL nanocomplex has enhanced ability to regenerate epithelium, also giving better keratinization, epidermal proliferation, and granulation tissue formation, compared to MEL, CTX, or positive control. The nanocomplex also significantly ameliorated the antioxidant status by decreasing malondialdehyde (MDA) and increasing superoxide dismutase (SOD) levels. The treatment of wounded skin with the CTX–MEL nanocomplex also showed a significant reduction in interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) pro-inflammatory cytokines combined with a substantial increase in hydroxyproline, VEFG-A, and TGF-β1 protein expression compared to individual components or negative control group. Additionally, the CTX–MEL nanocomplex showed a significant increase in mRNA expression levels of Col1A1 as compared to individual compounds. In conclusion, the ion-pairing nanocomplex of CTX–MEL represents a promising carrier that can be topically applied to improve wound healing.

Genistein and Momordica charantia L. prevent oxidative stress and upregulate proglucagon and insulin receptor mRNA in diabetic rats

Type 2 diabetes occurs as a result of insulin resistance and dysfunction in insulin signaling. Controlling hyperglycemia and activation of insulin signaling are important in the management of type 2 diabetes. This study aimed to evaluate the effect of genistein and Momordica charantia L. fruit (MCF) on oxidative stress, markers of inflammation, and their role in proglucagon and insulin receptor messenger RNA (mRNA) expression by real-time PCR in diabetic rats. Thirty-five albino rats were divided into 7 groups (n = 5). Group I (non-diabetic) and group II (diabetic control) were treated with distilled water, and groups III and IV received 250 mg/kg and 500 mg/kg lyophilized MCF, respectively. Groups V and VI received 10 mg/kg and 20 mg/kg genistein, respectively, while group VII received 500 mg/kg metformin. The administration lasted for 28 days. MCF and genistein significantly reduced interleukin (IL)-1β and tumor necrosis factor alpha (TNF-α) levels, which were elevated in the serum of diabetic rats. Treatment with MCF and genistein significantly increased the expression of proglucagon mRNA in the small intestine and insulin receptor mRNA in the liver of diabetic rats. In conclusion, MCF and genistein ameliorate type 2 diabetes complications by preventing the loss of insulin-positive cells, inhibiting IL-1β and TNF-α, and upregulating proglucagon and insulin receptor mRNA expression. Novelty: MCF and genistein have an inhibitory effect on diabetic induced IL-1β and TNF-α production. MCF and genistein upregulate proglucagon and insulin receptor mRNA expression.

Dietary Copper/Zinc Ratio and Type 2 Diabetes Risk in Women: The E3N Cohort Study

The serum copper (Cu) to zinc (Zn) ratio could be an important determinant of Type 2 diabetes (T2D) risk, but prospective epidemiological data are scarce. We aimed to investigate the association between T2D incidence and the dietary Cu/Zn ratio. A total of 70,991 women from the E3N cohort study were followed for 20 years. The intakes of copper and zinc were estimated at baseline using a validated food frequency questionnaire. We identified and validated 3292 incident T2D cases. Spline analysis showed that a Cu/Zn ratio < 0.55 was associated with a lower risk of T2D. Subgroup analyses comparing women in the highest versus the lowest quintile of Cu/Zn ratio showed the same pattern of association for obese women and those with zinc intake ≥8 mg/day. However, for women with zinc intake <8 mg/day, higher Cu/Zn ratio appeared to be associated with higher T2D risk. Our findings suggest that a lower dietary Cu/Zn ratio is associated with a lower T2D risk, especially among obese women and women with zinc intake >8 mg/day. Further studies are warranted to validate our results.

Targeting Inflammation by Anthocyanins as the Novel Therapeutic Potential for Chronic Diseases: An Update

Low-grade chronic inflammation (LGCI) and oxidative stress act as cooperative and synergistic partners in the pathogenesis of a wide variety of diseases. Polyphenols, including anthocyanins, are involved in regulating the inflammatory state and activating the endogenous antioxidant defenses. Anthocyanins' effects on inflammatory markers are promising and may have the potential to exert an anti-inflammatory effect in vitro and in vivo. Therefore, translating these research findings into clinical practice would effectively contribute to the prevention and treatment of chronic disease. The present narrative review summarizes the results of clinical studies from the last 5 years in the context of the anti-inflammatory and anti-oxidative role of anthocyanins in both health and disease. There is evidence to indicate that anthocyanins supplementation in the regulation of pro-inflammatory markers among the healthy and chronic disease population. Although the inconsistencies between the result of randomized control trials (RCTs) and meta-analyses were also observed. Regarding anthocyanins' effects on inflammatory markers, there is a need for long-term clinical trials allowing for the quantifiable progression of inflammation. The present review can help clinicians and other health care professionals understand the importance of anthocyanins use in patients with chronic diseases.

Glycoside Hydrolases and Non-Enzymatic Glycation Inhibitory Potential of Viburnum opulus L. Fruit-In Vitro Studies

Phytochemicals of various origins are of great interest for their antidiabetic potential. In the present study, the inhibitory effects against carbohydrate digestive enzymes and non-enzymatic glycation, antioxidant capacity, and phenolic compounds composition of Viburnum opulus L. fruits have been studied. Crude extract (CE), purified extract (PE), and ethyl acetate (PEAF) and water (PEWF) fractions of PE were used in enzymatic assays to evaluate their inhibitory potential against α-amylase with potato and rice starch as substrate, α-glucosidase using maltose and sucrose as substrate, the antioxidant capacity (ABTS, ORAC and FRAP assays), antiglycation (BSA-fructose and BSA-glucose model) properties. Among four tested samples, PEAF not only had the highest content of total phenolics, but also possessed the strongest α-glucosidase inhibition, antiglycation and antioxidant activities. UPLC analysis revealed that this fraction contained mainly chlorogenic acid, proanthocyanidin oligomers and flavalignans. Contrary, the anti-amylase activity of V. opulus fruits probably occurs due to the presence of proanthocyanidin polymers and chlorogenic acids, especially dicaffeoylquinic acids present in PEWF. All V. opulus samples have an uncompetitive and mixed type inhibition against α-amylase and α-glucosidase, respectively. Considering strong anti-glucosidase, antioxidant and antiglycation activities, V. opulus fruits may find promising applications in nutraceuticals and functional foods with antidiabetic activity.

Gastric Electrical Pacing Reduces Apoptosis of Interstitial Cells of Cajal via Antioxidative Stress Effect Attributing to Phenotypic Polarization of M2 Macrophages in Diabetic Rats

BACKGROUND

Gastric electrical pacing (GEP) could restore interstitial cells of Cajal in diabetic rats. M2 macrophages contribute to the repair of interstitial cells of Cajal injury though secreting heme oxygenase-1 (HO-1). The aim of the study is to investigate the effects and mechanisms of gastric electrical pacing on M2 macrophages in diabetic models.

METHODS

Sixty male Sprague-Dawley rats were randomized into control, diabetic (DM), diabetic with the sham GEP (DM+SGEP), diabetic with GEP1 (5.5 cpm, 100 ms, 4 mA) (DM+GEP1), diabetic with GEP2 (5.5 cpm, 300 ms, 4 mA) (DM+GEP2), and diabetic with GEP3 (5.5 cpm, 550 ms, 4 mA) (DM+GEP3) groups. The apoptosis of interstitial cells of Cajal and the expression of macrophages were detected by immunofluorescence technique. The expression levels of the Nrf2/HO-1 and NF-κB pathway were evaluated using western blot analysis or immunohistochemical method. Malonaldehyde, superoxide dismutase, and reactive oxygen species were tested to reflect the level of oxidative stress.

RESULTS

Apoptosis of interstitial cells of Cajal was increased in the DM group but significantly decreased in the DM+GEP groups. The total number of macrophages was almost the same in each group. In the DM group, M1 macrophages were increased and M2 macrophages were decreased. However, M2 macrophages were dramatically increased and M1 macrophages were reduced in the DM+GEP groups. Gastric electrical pacing improved the Nrf2/HO-1 pathway and downregulated the phosphorylation of NF-κB. In the DM group, the levels of malonaldehyde and reactive oxygen species were elevated and superoxide dismutase was lowered, while gastric electrical pacing reduced the levels of malonaldehyde and reactive oxygen species and improved superoxide dismutase.

CONCLUSION

Gastric electrical pacing reduces apoptosis of interstitial cells of Cajal though promoting M2 macrophages polarization to play an antioxidative stress effect in diabetic rats, which associates with the activated Nrf2/HO-1 pathway and the phosphorylation of NF-κB pathway.

Effect of Plantain Bulb's Extract-Beverage Blend on Blood Glucose Levels, Antioxidant Status, and Carbohydrate Hydrolysing Enzymes in Streptozotocin-Induced Diabetic Rats

The pharmacological properties of various parts of plantain trees have directed its use in folkloric management of diabetes and other human ailments. However, little is known about plantain bulb extract (PBE) and their mechanisms of action. This study evaluated the effect of PBE-beverage blends (including 1% and 2 % cocoa powder) sweetened with honey on blood glucose levels, antioxidant status, and carbohydrate hydrolysing enzyme activities in streptozotocin (STZ)-induced diabetic rats. Animals were selected at random and distributed into 7 groups (n=7), as follows: normal control (NC), untreated diabetic rats, diabetic rats treated with acarbose (STZ-ACA), diabetic rats administered PBE (STZ- PBE), diabetic rats administered honey and PBE (STZ-HPBE), diabetic rats administered 1% cocoa powder-with HPBE blend (STZ-CHPBE-1), and diabetic rats administered 2% cocoa powder with HPBE blend (STZ-CHPBE-2). Compared with the controls, untreated diabetic rats exhibited increased blood glucose levels and hydrolysing enzyme activities, and significant decreases in the activities of antioxidant (catalase, superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase) enzyme and non-enzymatic (glutathione) antioxidants. However, changes in activities were comparatively reversed in all rats administered plantain bulb formulations. CHPBE-2 was slightly more effective than CHPBE-1. Overall, both blends could serve as nutraceutical and/or functional drinks in the management of diabetes.

Gustavia gracillima Miers. flowers effects on enzymatic targets underlying metabolic disorders and characterization of its polyphenolic content by HPLC-DAD-ESI/MSn

Notwithstanding Gustavia gracillima Miers widespread distribution in neotropical regions, its chemical profile and biological properties remain uninvestigated. A methanol extract obtained from the flowers was characterized through HPLC-DAD-ESI/MSⁿ, nine ellagic acid derivatives and twelve kaempferol 3-O-glycosides being identified and quantitated for the first time at the species and genus. Preliminary cytotoxicity screening did not reveal noticeable effects upon gastrointestinal representative cell lines (AGS, Caco-2 and Hep G2), which further prompted us to evaluate the impact in a series of targets involved in metabolic disorders and associated complications. Despite of the moderate inhibition towards 5-lipoxygense activity, G. gracillima methanol extract displayed significant effects on carbohydrates-hydrolysing enzymes. In contrast with the antidiabetic reference drug acarbose, the extract was able to selectively inhibit yeast α-glucosidase activity (IC₅₀ = 4.72 µg/mL), with negligible inhibitory effects upon α-amylase. Kinetic studies pointed to a model of mixed inhibition with a great binding activity, characterized by an inhibitory constant of 2.91 µg/mL. The notable inhibitory activity was also confirmed in α-glucosidase homogenates isolated from human intestinal cells (IC₅₀ = 34.03 µg/mL). Moreover, the extract obtained from the flowers of G. gracillima displayed significant aldose reductase inhibition (IC₅₀ = 61.88 µg/mL), as well as O₂^- and NO scavenging properties. A moderate inhibitory effect was also recorded against pancreatic lipase (IC₅₀ = 362.17 µg/mL) through a mixed inhibition mode. Recorded data supports the potential incorporation of G. gracillima flowers on antidiabetic herbal formulations and/or supplements, with not only straight action on carbohydrates digestion, but also direct interference with targets involved on subsequent diabetes events, such as triglycerides metabolism, inflammation and radical-mediated stress.

CML/RAGE Signal Bridges a Common Pathogenesis Between Atherosclerosis and Non-alcoholic Fatty Liver

Non-alcoholic fatty liver disease (NAFLD) has become a common chronic disease in the world. NAFLD is not only a simple intrahepatic lesion, but also affects the occurrence of a variety of extrahepatic complications. In particular, cardiovascular complications are particularly serious, which is the main cause of death in patients with NAFLD. To study the relationship between NAFLD and AS may be a new way to improve the quality of life in patients with NAFLD. As we all known, inflammatory response plays an important role in the occurrence and development of NAFLD and AS. In this study, we found that the accumulation of Nε-carboxymethyllysine (CML) in the liver leads to hepatic steatosis. CML can induce the expression of interleukin (IL-1β), interleukin (IL-6), tumor necrosis factor (TNF-α), C-reactionprotein (CRP) by binding with advanced glycosylation end-product receptor (RAGE) and accelerate the development of AS. After silencing RAGE expression, the expression of pro-inflammatory cytokines was inhibited and liver and aorta pathological changes were relieved. In conclusion, CML/RAGE signal promotes the progression of non-alcoholic fatty liver disease and atherosclerosis. We hope to provide new ideas for the study of liver vascular dialogue in multi organ communication.

Lentivirus Mediated Pancreatic Beta-Cell-Specific Insulin Gene Therapy for STZ-Induced Diabetes

Autoimmune destruction of pancreatic beta cells is the characteristic feature of type 1 diabetes mellitus. Consequently, both short- and intermediate-acting insulin analogs are under development to compensate for the lack of endogenous insulin gene expression. Basal insulin is continuously released at low levels in response to hepatic glucose output, while post-prandial insulin is secreted in response to hyperglycemia following a meal. As an alternative to multiple daily injections of insulin, glucose-regulated insulin gene expression by gene therapy is under development to better endure postprandial glucose excursions. Controlled transcription and translation of proinsulin, presence of glucose-sensing machinery, prohormone convertase expression, and a regulated secretory pathway are the key features unique to pancreatic beta cells. To take advantage of these hallmarks, we generated a new lentiviral vector (LentiINS) with an insulin promoter driving expression of the proinsulin encoding cDNA to sustain pancreatic beta-cell-specific insulin gene expression. Intraperitoneal delivery of HIV-based LentiINS resulted in the lowering of fasting plasma glucose, improved glucose tolerance and prevented weight loss in streptozoticin (STZ)-induced diabetic Wistar rats. However, the combinatorial use of LentiINS and anti-inflammatory lentiviral vector (LentiVIP) gene therapy was required to increase serum insulin to a level sufficient to suppress non-fasting plasma glucose and diabetes-related inflammation.

Antidiabetic effect of olive leaf extract on streptozotocin-induced diabetes mellitus in experimental animals

Introduction

Background: recently, a relationship between diabetic complications and oxidative stress has been emphasized. There have been some studies showing the effect of olive leaf on hyperglycemia and diabetic complications due to its antioxidant properties. In many studies the effect of olive leaf on plasma total antioxidant level has been measured by different methods. Our study represents the first time it has been measured by a new method of total thiol disulfide homeostasis. Aim: chronic exposure to hyperglycemia and hyperlipidemia contributes to the pathogenesis of diabetic complications through oxidative stress mediators. Thiol is one of the most important antioxidant barriers in humans, and thiol disulfide homeostasis is a new oxidative stress marker. We aimed to investigate the effect of olive leaf extract (OLE) obtained from fresh leaves of Olea europaea, var oleaster on diabetic complications through their hypoglycemic and antioxidant effect in diabetic rats. Methods: twenty-eight Wistar albino rats aged 12-13 weeks were used in the study. The rats were divided into a control group (C), a diabetic control group (DC), a diabetic group treated with 200 mg/kg OLE (D+200), and a diabetic group treated with 400 mg/kg OLE (D+400), having 7 rats in each group. The treatment groups received OLE by the gavage method for 21 days. At the end of the study, all rats were sacrificed by cervical dislocation. Blood samples collected from the heart were centrifuged and glucose, total cholesterol, triglyceride, urea, uric acid, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipid hydroperoxide (LOOH) level, and thiol-disulfide homeostasis were determined. The hemoglobin A1c (HbA1c) analysis was performed on complete blood. In addition, a tail flick test and hot plate modeling were performed to indicate pain perception loss. Results: it was observed that OLE had no effect on serum glucose and HbA1c levels. On the contrary, OLE reduced the levels of total cholesterol (p < 0.01), urea (p < 0.01) and hot plate latency (p < 0.01) in a significant manner. Also, OLE showed a tendency to reduce LOOH levels and to increase thiol levels in a dose-dependent manner (p > 0.05). Conclusion: OLE supplementation for 21 days, at the amounts used, cannot protect against hyperglycemia but may be protective against hypercholesterolemia and tissue damage as caused by diabetes mellitus in rats.

Valorisation of kitul, an overlooked food plant: Phenolic profiling of fruits and inflorescences and assessment of their effects on diabetes-related targets

Caryota urens L. has long been valued as a traditional food, the edible fruits being eaten raw and the inflorescences commonly used on sweet sap and flour production. In the current work, the phenolic profile of methanol extracts obtained from the inflorescences and fruits was unveiled for the first time, nine caffeic acid derivatives being identified and quantified. Since kitul products have been reported for their antidiabetic properties, extracts radical scavenging activity and α-amylase, α-glucosidase and aldose reductase inhibitory activity were assessed. The inflorescences' extract was particularly active against yeast α-glucosidase (IC₅₀ = 1.53 μg/mL), acting through a non-competitive inhibitory mechanism. This activity was also observed in enzyme-enriched homogenates obtained from human Caco-2 cells (IC₅₀ = 64.75 µg/mL). Additionally, the extract obtained from the inflorescences showed no cytotoxicity on HepG2, AGS and Caco-2 cell lines. Our data suggest that C. urens inflorescences can support the development of new functional foods with α-glucosidase inhibitory activity.

Vanadium: Risks and possible benefits in the light of a comprehensive overview of its pharmacotoxicological mechanisms and multi-applications with a summary of further research trends

BACKGROUND

Vanadium (V) is an element with a wide range of effects on the mammalian organism. The ability of this metal to form organometallic compounds has contributed to the increase in the number of studies on the multidirectional biological activity of its various organic complexes in view of their application in medicine.

OBJECTIVE

This review aims at summarizing the current state of knowledge of the pharmacological potential of V and the mechanisms underlying its anti-viral, anti-bacterial, anti-parasitic, anti-fungal, anti-cancer, anti-diabetic, anti-hypercholesterolemic, cardioprotective, and neuroprotective activity as well as the mechanisms of appetite regulation related to the possibility of using this element in the treatment of obesity. The toxicological potential of V and the mechanisms of its toxic action, which have not been sufficiently recognized yet, as well as key information about the essentiality of this metal, its physiological role, and metabolism with certain aspects on the timeline is collected as well. The report also aims to review the use of V in the implantology and industrial sectors emphasizing the human health hazard as well as collect data on the directions of further research on V and its interactions with Mg along with their character.

RESULTS AND CONCLUSIONS

Multidirectional studies on V have shown that further analyses are still required for this element to be used as a metallodrug in the fight against certain life-threatening diseases. Studies on interactions of V with Mg, which showed that both elements are able to modulate the response in an interactive manner are needed as well, as the results of such investigations may help not only in recognizing new markers of V toxicity and clarify the underlying interactive mechanism between them, thus improving the medical application of the metals against modern-age diseases, but also they may help in development of principles of effective protection of humans against environmental/occupational V exposure.

Pathophysiology of atherosclerosis: Association of risk factors and treatment strategies using plant-based bioactive compounds

Under physiological conditions, endothelial cells act as protective barrier which prevents direct contact of blood with circulating factors via production of tissue plasminogen activator. Risk factors of metabolic disorders are responsible to induce endothelial dysfunction and may consequently lead to prognosis of atherosclerosis. This article summarizes the process of atherosclerosis which involves number of sequences including formation and interaction of AGE-RAGE, activation of polyol pathway, protein kinase C, and hexosamine-mediated pathway. All these mechanisms can lead to the development of oxidative stress which may further aggravate condition. Different pharmacological interventions are being used to treat atherosclerosis, however, these might be associated with mild to severe side effects. Therefore, plant-based bioactive compounds having potential to combat and prevent atherosclerosis in diabetic patients are attaining recent focus. By understanding process of development and mechanisms involved in atherosclerotic plaque formation, these bioactive compounds can be better option for future therapeutic interventions for atherosclerosis treatment. PRACTICAL APPLICATIONS: Atherosclerosis is one of major underlying disorders of cardiovascular diseases which occur through multiple mechanisms and is associated with metabolic disorders. Conventional therapeutic interventions are not only used to treat atherosclerosis, but are also commonly associated with mild to severe side effects. Therefore, nowadays, bioactive compounds having potential to combat and prevent atherosclerosis in diabetic patients are preferred. By understanding mechanisms involved in atherosclerotic plaque formation, bioactive compounds can be better understood for treatment of atherosclerosis. In this manuscript, we have focused on treatment strategies of atherosclerosis using bioactive compounds notably alkaloids and flavonoids having diverse pharmacological and therapeutic potentials with special focus on the mechanism of action of these bioactive compounds suitable for treatment of atherosclerosis. This manuscript will provide the scientific insights of bioactive compounds to researchers who are working in the area of drug discovery and development to control pathogenesis and development of atherosclerosis and its associated cardiometabolic disorders.