The Protective Effect of Antioxidants Consumption on Diabetes and Vascular Complications

Physical health effects of sedentary behaviour on adults with an intellectual disability: A scoping review

This literature review was designed to establish the effects of sedentary behaviour on the physical health of adults with an intellectual disability. Sedentary behaviour is defined as any waking behaviour characterized by an energy expenditure of ≤1.5 METs while in a sitting, lying or reclining posture. An extensive search was executed in six databases: EMBASE, Medline, CINAHL, PsycINFO, ASSIA and Web of Science. Following screening, 18 articles remained for inclusion in the review. A thematic analysis using the Braun and Clarke six step process resulted in the identification of seven broad health areas. Studies showed a prevalence of obesity, multimorbidity and metabolic syndrome as well as elevated levels of sedentary behaviour in adults with an intellectual disability. This literature review demonstrated that sedentary behaviour could be a contributor to the poor health which is common in adults with an intellectual disability. However to date the body of evidence does not confirm a cause-and-effect relationship.

Solarplast® Demonstrates Anti-Inflammatory and Anti-Oxidant Activity In Vivo and Positively Modulates Perceived Anti-Ageing Quality of Life Questionnaire and Skin Analogue Scale

Solarplast® is an organic, non-GMO (genetically modified organism) dietary supplement from an enzymatically treated spinach preparation containing numerous active components that exhibit antioxidative and anti-inflammatory properties. The purpose of this study was to evaluate the effects of a 45-day supplementation period in adult men and women (Total n = 84), some of whom were classified as "everyday smokers". The main outcomes include metabolic readouts, oxidative stress, inflammation, and secondary subjective assessments, including skin, physical, and mental health questionnaires. Solarplast® attenuated some markers associated with smoking-induced increases in inflammatory tone and oxidative stress markers. Furthermore, Solarplast® administration improved anti-ageing quality of life mental scores associated with depression-related symptoms, loss of self-confidence, and some anxiety-related symptoms and exhibited positive effects in some readouts of anti-ageing quality of life physical scores and skin visual analogue scores. In summary, Solarplast® is safe, well-tolerated, may reduce circulating inflammatory and oxidative stress markers, and may positively impact some mental and physical quality-of-life parameters as well as skin quality.

Diet and Nutraceuticals for treatment and prevention of primary and secondary stroke: Emphasis on nutritional antiplatelet and antithrombotic agents

Ischemic stroke is a devastating disease that causes morbidity and mortality. Malnutrition following ischemic stroke is common in stroke patients. During the rehabilitation, the death rates of stroke patients are significantly increased due to malnutrition. Nutritional supplements such as protein, vitamins, fish, fish oils, moderate wine or alcohol consumption, nuts, minerals, herbal products, food colorants, marine products, fiber, probiotics and Mediterranean diets have improved neurological functions in stroke patients as well as their quality of life. Platelets and their mediators contribute to the development of clots leading to stroke. Ischemic stroke patients are treated with thrombolytics, antiplatelets, and antithrombotic agents. Several systematic reviews, meta-analyses, and clinical trials recommended that consumption of these nutrients and diets mitigated the vascular, peripheral, and central complications associated with ischemic stroke (Fig. 2). Particularly, these nutraceuticals mitigated the platelet adhesion, activation, and aggregation that intended to reduce the risks of primary and secondary stroke. Although these nutraceuticals mitigate platelet dysfunction, there is a greater risk of bleeding if consumed excessively. Moreover, malnutrition must be evaluated and adequate amounts of nutrients must be provided to stroke patients during intensive care units and rehabilitation periods. In this review, we have summarized the importance of diet and nutraceuticals in ameliorating neurological complications and platelet dysfunction with an emphasis on primary and secondary prevention of ischemic stroke.

Concentrations of Glypican-4, Irisin and Total Antioxidant Status in Women with Metabolic Syndrome: Influence of Physical Activity

Glypican-4 belongs to a group of poorly understood adipokines, with potential importance in people with metabolic syndrome, especially in groups of patients with glucose metabolism disorder. This study aimed to assess the effect of physical activity on serum glypican-4 and irisin levels and total antioxidant status (TAS) in plasma and saliva in women with metabolic syndrome (MetS). Seventy-two Caucasian women aged 25-60 were included in the study (36 women with MetS and 36 women without MetS (control group, CONTR)). The glypican-4 and irisin concentrations, total antioxidant status, glycemia, lipid profile, anthropometric parameters, and blood pressure were analyzed before and after 28 days of controlled physical activity. Serum glypican-4 and plasma TAS levels were higher (p = 0.006 and p = 0.043, respectively) on the 28th day than on the first day of the study only in the CONTR group. In the MetS group, 28 days of physical activity caused a reduction in body fat mass (p = 0.049) without changes in glypican-4, irisin, or TAS levels. In both groups, glypican-4 levels correlated positively with irisin levels and negatively with Waist-Hip Ratio (WHR), while irisin levels correlated positively with High-Density Lipoprotein Cholesterol (HDL-C) levels and negatively with waist circumference (WC) and WHR values on the 28th day of the study. To summarize, a 28-day moderate training, accompanied by a reduction in body fat mass, stabilized glypican-4 levels and TAS in female patients with MetS.

Coenzyme Q10: A Key Antioxidant in the Management of Diabetes-Induced Cardiovascular Complications-An Overview of Mechanisms and Clinical Evidence

Background

Diabetes mellitus (DM) presents a significant global health challenge with considerable cardiovascular implications. Coenzyme Q10 (CoQ10) has gained recognition for its potential as a natural antioxidant supplement in the management of diabetes and its associated cardiovascular complications.

Aim

This comprehensive review systematically examines the scientific rationale underlying the therapeutic properties of CoQ10 in mitigating the impact of diabetes and its cardiovascular consequences. The analysis encompasses preclinical trials (in vitro and in vivo) and clinical studies evaluating the efficacy and mechanisms of action of CoQ10. Result & Discussion. Findings reveal that CoQ10, through its potent antioxidant and anti-inflammatory attributes, demonstrates significant potential in reducing oxidative stress, ameliorating lipid profiles, and regulating blood pressure, which are crucial aspects in managing diabetes-induced cardiovascular complications. CoQ10, chemically represented as C59H90O4, was administered in capsule form for human studies at doses of 50, 100, 150, 200, and 300 mg per day and at concentrations of 10 and 20 μM in sterile powder for experimental investigations and 10 mg/kg in powder for mouse studies, according to the published research. Clinical trials corroborate these preclinical findings, demonstrating improved glycemic control, lipid profiles, and blood pressure in patients supplemented with CoQ10.

Conclusion

In conclusion, CoQ10 emerges as a promising natural therapeutic intervention for the comprehensive management of diabetes and its associated cardiovascular complications. Its multifaceted impacts on the Nrf2/Keap1/ARE pathway, oxidative stress, and metabolic regulation highlight its potential as an adjunct in the treatment of diabetes and related cardiovascular disorders. However, further extensive clinical investigations are necessary to fully establish its therapeutic potential and assess potential synergistic effects with other compounds.

Effect of Prunetin on Streptozotocin-Induced Diabetic Nephropathy in Rats - a Biochemical and Molecular Approach

In the modern era, chronic kidney failure due to diabetes has spread across the globe. Prunetin (PRU), a component of herbal medicines, has a broad variety of pharmacological activities; these may help to slow the onset of diabetic kidney disease. The anti-nephropathic effects of PRU have not yet been reported. The present study explored the potential nephroprotective actions of PRU in diabetic rats. For 28 days, nephropathic rats were given oral doses of PRU (20, 40, and 80 mg/kg). Body weight, blood urea, creatinine, total protein, lipid profile, liver marker enzymes, carbohydrate metabolic enzymes, C-reactive protein, antioxidants, lipid peroxidative indicators, and the expression of insulin receptor substrate 1 (IRS-1) and glucose transporter 2 (GLUT-2) mRNA genes were all examined. Histological examinations of the kidneys, liver, and pancreas were also performed. The oral treatment of PRU drastically lowered the blood glucose, HbA1c, blood urea, creatinine, serum glutamic-oxaloacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase, lipid profile, and hexokinase. Meanwhile, the levels of fructose 1,6-bisphosphatase, glucose-6-phosphatase, and phosphoenol pyruvate carboxykinase were all elevated, but glucose-6-phosphate dehydrogenase dropped significantly. Inflammatory marker antioxidants and lipid peroxidative markers were also less persistent due to this administration. PRU upregulated the IRS-1 and GLUT-2 gene expression in the nephropathic group. The possible renoprotective properties of PRU were validated by histopathology of the liver, kidney, and pancreatic tissues. It is therefore proposed that PRU (80 mg/kg) has considerable renoprotective benefits in diabetic nephropathy in rats.

Solarplast®-An Enzymatically Treated Spinach Extract

In the modern world we are constantly bombarded by environmental and natural stimuli that can result in oxidative stress. Antioxidant molecules and enzymes help the human body scavenge reactive oxygen species and prevent oxidative damage. Most organisms possess intrinsic antioxidant activity, but also benefit from the consumption of antioxidants from their diet. Leafy green vegetables such as spinach are a well-researched rich source of dietary antioxidant molecules. However, plant cell walls are difficult to digest for many individuals and the bio-accessibility of nutrients and antioxidants from these sources can be limited by the degree of digestion and assimilation. Through a specific enzymatic process, Solarplast^® contains organic spinach protoplasts without the cell wall, which may facilitate higher yield and efficacy of beneficial antioxidant molecules. In this study, analytical techniques coupled to in vitro bioassays were used to determine the potential antioxidant activity of Solarplast^® and determine its antioxidant enzymatic capabilities. Solarplast^® demonstrated superior antioxidant activity when compared to frozen spinach leaves in TOC, FRAP and TEAC antioxidant assays. Several antioxidant enzymes were also increased in Solarplast^®, when compared to frozen spinach. As a functional readout, Solarplast^® attenuated hydrogen peroxide-, ethanol- and acetaminophen-induced increases in oxidative stress and cytotoxicity in both intestinal (HT-29) and liver (HepG2) cell lines. These findings suggest that Solarplast^® may represent a non-GMO, plant-based food supplement to help reduce oxidative stress in the human body.

Assessments of Alpha-Amylase Inhibitory Potential of Tagetes Flavonoids through In Vitro, Molecular Docking, and Molecular Dynamics Simulation Studies

Diabetes is a chronic fast-growing metabolic disorder that is characterized by high blood glucose levels. Tagetes minuta L. has been used as a traditional remedy for various illnesses for many years, and, furthermore, its oil is used in the perfume and flavor industries. T. minuta contains various metabolites, such as flavonoids, thiophenes, terpenes, sterols, and phenolics, with varied bioactivities. Flavonoids can inhibit carbohydrate-digesting enzymes, such as alpha-amylase, which is a convenient dietary strategy for controlling hyperglycemia. In the current investigation, the isolated flavonoids quercetagetin-6-O-(6-O-caffeoyl-β-D-glucopyranoside), quercetagetin-7-O-β-D-glucopyranoside, quercetagetin-6-O-β-D-glucopyranoside, minutaside A, patuletin-7-O-β-D-glucopyranoside, quercetagetin-7-methoxy-6-O-β-D-glucopyranoside, tagenols A and B, quercetagetin-3,7-dimethoxy-6-O-β-D-glucopyranoside, patuletin, quercetin-3,6-dimethyl ether, and quercetin-3-methyl ether from T. minuta were assessed for their alpha-amylase inhibition (AAI) efficacy using an in vitro assay, as well as molecular docking, dynamics simulation, and ADMET analyses. Our findings show that quercetagetin-6-O-(6-O-caffeoyl-β-D-glucopyranoside) (1), quercetagetin-7-O-β-D-glucopyranoside (2), quercetagetin-6-O-β-D-glucopyranoside (3), minutaside A (4), patuletin-7-O-β-D-glucopyranoside (5), and quercetagetin-7-methoxy-6-O-β-D-glucopyranoside (6) had a notable AAI capacity (IC₅₀s ranged from 7.8 to 10.1 μM) compared to acarbose (IC₅₀ 7.1 μM). Furthermore, these compounds with the highest binding affinity among the tested flavonoids revealed high docking scores for AA (ranging from -12.171 to 13.882 kcal/mol) compared to that of acarbose (-14.668 kcal/mol). In MDS, these compounds were observed to show maximum stability and the greatest binding free energy, suggesting that they may contend with native ligands. In addition, the ADMET analysis showed that these active compounds had a broad span of drug-like, pharmacokinetic, and physicochemical features and did not possess any considerable undesired effects. The current results suggest the potential of these metabolites as AAI candidates. However, further in vivo and mechanistic studies are warranted to specify the efficacy of these metabolites.

Lauric acid improves hormonal profiles, antioxidant properties, sperm quality and histomorphometric changes in testis and epididymis of streptozotocin-induced diabetic infertility rats

Lauric acid, a 12‑carbon atom medium chain fatty acid (MCFA) has strong antioxidant and antidiabetic activities. However, whether lauric acid can ameliorate hyperglycaemia-induced male reproductive damage remains unclear. The study aimed to determine the optimal dose of lauric acid with glucose-lowering activity, antioxidant potential and tissue-protective effects on the testis and epididymis of streptozotocin (STZ)-induced diabetic rats. Hyperglycaemia was induced in Sprague Dawley rats by an intravenous injection of STZ at a dose of 40 mg/kg body weight (bwt). Lauric acid (25, 50 and 100 mg/kg bwt) was administered orally for eight weeks. Weekly fasting blood glucose (FBG), glucose tolerance and insulin sensitivity were examined. Hormonal profiles (insulin and testosterone), lipid peroxidation (MDA) and antioxidant enzyme (SOD and CAT) activities were measured in the serum, testis and epididymis. The reproductive analyses were evaluated based on sperm quality and histomorphometry. Lauric acid administration significantly improved FBG levels, glucose tolerance, hormones-related fertility and oxidant-antioxidant balance in the serum, testis and epididymis compared to untreated diabetic rats. Treatment with lauric acid preserved the testicular and epididymal histomorphometry, along with the significant improvements in sperm characteristics. It is shown for the first time that lauric acid treatment at 50 mg/kg bwt is the optimal dose for ameliorating hyperglycaemia-induced male reproductive complications. We conclude that lauric acid reduced hyperglycaemia by restoring insulin and glucose homeostasis, which attributes to the regeneration of tissue damage and sperm quality in STZ-induced diabetic rats. These findings support the correlation between oxidative stress and hyperglycaemia-induced male reproductive dysfunctions.

The role of dietary antioxidants in type 2 diabetes and neurodegenerative disorders: An assessment of the benefit profile

Healthy diet is vital to cellular health. The human body succumbs to numerous diseases which afflict severe economic and psychological burdens on the patient and family. Oxidative stress is a possible crucial regulator of various pathologies, including type 2 diabetes and neurodegenerative diseases. It generates reactive oxygen species (ROS) that trigger the dysregulation of essential cellular functions, ultimately affecting cellular health and homeostasis. However, lower levels of ROS can be advantageous and are implicated in a variety of signaling pathways. Due to this dichotomy, the terms oxidative "eustress," which refers to a good oxidative event, and "distress," which can be hazardous, have developed. ROS affects multiple signaling pathways, leading to compromised insulin secretion, insulin resistance, and β-cell dysfunction in diabetes. ROS is also associated with increased mitochondrial dysfunction and neuroinflammation, aggravating neurodegenerative conditions in the body, particularly with age. Treatment includes drugs/therapies often associated with dependence, side effects including non-selectivity, and possible toxicity, particularly in the long run. It is imperative to explore alternative medicines as an adjunct therapy, utilizing natural remedies/resources to avoid all the possible harms. Antioxidants are vital components of our body that fight disease by reducing oxidative stress or nullifying the excess toxic free radicals produced under various pathological conditions. In this review, we focus on the antioxidant effects of components of dietary foods such as tea, coffee, wine, oils, and honey and the role and mechanism of action of these antioxidants in alleviating type 2 diabetes and neurodegenerative disorders. We aim to provide information about possible alternatives to drug treatments used alone or combined to reduce drug intake and encourage the consumption of natural ingredients at doses adequate to promote health and combat pathologies while reducing unwanted risks and side effects.

Study of the Antioxidant Properties of Filipendula ulmaria and Alnus glutinosa

The demographic situation of the last few decades is characterized by the increased numbers of elderly and senile people, i.e., by the aging of the population. In humans, ageing is closely associated with the enhanced production of reactive oxygen species (ROS), development of systemic inflammation and related vascular atherosclerotic alterations and metabolic disorders, like obesity, diabetes mellitus and neurodegenerative diseases. As these age-related alterations are directly associated with up-regulation of ROS production and development of chronic oxidative stress, their onset can be essentially delayed by continuous daily consumption of dietary antioxidants-natural products of plant origin. Such antioxidants (in the form of plant extracts, biologically active complexes or individual compounds) can be supplemented to functional foods, i.e., dietary supplementations for daily diet aiming prolongation of active life and delay of the senescence onset. Thereby, use of widely spread medicinal plants might essentially improve cost efficiency of this strategy and availability of antioxidant-rich functional foods. Therefore, here we addressed, to the best of our knowledge for the first time, the antioxidant activity of the extracts prepared from the aerial parts of Filipendula ulmaria and Alnus glutinosa growing in the Kaliningrad region of Russia, and assessed the contents of the biologically active substances underlying these properties. It was found that the extract prepared with the leaves of Filipendula ulmaria and female catkins of Alnus glutinosa demonstrated high antioxidant activity, although the former plant was featured with a higher antioxidant potential. The highest antioxidant activity detected in the methanol extracts of Alnus glutinosa reached 1094.02 ± 14.53 µmol TE/g, radical scavenging of activity was 584.45 ± 35.3 µmol TE/g, reducing capacity at interaction with iron complex-471.63 ± 7.06 µmol TE/g. For the methanol extracts of Filipendula ulmaria the antioxidant activity reached 759.78 ± 19.08 µmol TE/g, antioxidant activity for free radical removal was 451.08 ± 24.45 µmol TE/g and antioxidant activity for restorative ability with iron complex was 332.28 ± 10.93 µmol TE/g. These values are consistent with the total yields of the extracts and their content of ellagic acid. The ethyl acetate extracts of the both plants showed just minimal antioxidant activity. Thus, the considered extracts have an essential potential. This creates good prospects for the further use of herbal extracts of Filipendula ulmaria and Alnus glutinosa as a source of natural antioxidants.

Bioactive nutraceutical ligands and their efficiency to chelate elemental iron of varying dynamic oxidation states to mitigate associated clinical conditions

The natural bioactive or nutraceuticals exhibit several health benefits, including anti-inflammatory, anti-cancer, metal chelation, antiviral, and antimicrobial activity. The inherent limitation of nutraceuticals or bioactive ligand(s) in terms of poor pharmacokinetic and other physicochemical properties affects their overall therapeutic efficiency. The excess of iron in the physiological compartments and its varying dynamic oxidation state [Fe(II) and Fe(III)] precipitates various clinical conditions such as non-transferrin bound iron (NTBI), labile iron pool (LIP), ferroptosis, cancer, etc. Though several natural bioactive ligands are proposed to chelate iron, the efficiency of bioactive ligands is limited due to poor bioavailability, denticity, and other related physicochemical properties. The present review provides insight into the relevance of studying the dynamic oxidation state of iron(II) and iron(III) in the physiological compartments and its clinical significance for selecting diagnostics and therapeutic regimes. We suggested a three-pronged approach, i.e., diagnosis, selection of therapeutic regime (natural bioactive), and integration of novel drug delivery systems (NDDS) or nanotechnology-based principles. This systematic approach improves the overall therapeutic efficiency of natural iron chelators to manage iron overload-related clinical conditions.

Anti-Hyperglycemic Effect of Magnesium-Enhanced Alkaline-Reduced Water on High Glucose-Induced Oxidative Stress in Renal Tubular Epithelial Cells

Diabetes is coupled with hyperglycemia, a state in which elevated glucose levels trigger oxidative stress (OS) in various body functions. One of the organs most afflicted by diabetes is the kidney. Despite this, specific treatments to mitigate the harmful effects of hyperglycemia-induced OS in the kidney have not been extensively explored. This study evaluates the anti-hyperglycemic efficacy of magnesium-enhanced alkaline-reduced water (MARW) in human kidney-2 (HK-2) cells. OS, mitogen-activated protein kinase (MAPK) signaling and fibrosis markers were assessed in high glucose (HG)-induced HK-2 cells, followed by treatment with experimental water for 24 h. Surprisingly, MARW rescued the vitality of HG-induced HK-2 cells, in contrast to that seen with other experimental waters. Additionally, MARW maintained reactive oxygen species, nitric oxide, catalase, glutathione peroxidase, hepatocyte growth factor and glucose uptake in HG-induced HK-2 cells but not in tap water and mineral water. Similarly, MARW downregulated the expression of MAPK and fibrosis-linked signaling proteins such as p-p38, phospho-c-Jun N-terminal kinase, α-smooth muscle actin, matrix metalloproteinase-3 and cleaved caspase 3 in HG-induced HK-2 cells. In conclusion, MARW protects HK-2 cells from the deleterious effects of HG by stabilizing antioxidant defenses and by signaling cascades related to metabolism, apoptosis and fibrosis.

Phytotherapeutic Approaches to the Prevention of Age-Related Changes and the Extension of Active Longevity

Maintaining quality of life with an increase in life expectancy is considered one of the global problems of our time. This review explores the possibility of using natural plant compounds with antioxidant, anti-inflammatory, anti-glycation, and anti-neurodegenerative properties to slow down the onset of age-related changes. Age-related changes such as a decrease in mental abilities, the development of inflammatory processes, and increased risk of developing type 2 diabetes have a significant impact on maintaining quality of life. Herbal preparations can play an essential role in preventing and treating neurodegenerative diseases that accompany age-related changes, including Alzheimer’s and Parkinson’s diseases. Medicinal plants have known sedative, muscle relaxant, neuroprotective, nootropic, and antiparkinsonian properties. The secondary metabolites, mainly polyphenolic compounds, are valuable substances for the development of new anti-inflammatory and hypoglycemic agents. Understanding how mixtures of plants and their biologically active substances work together to achieve a specific biological effect can help develop targeted drugs to prevent diseases associated with aging and age-related changes. Understanding the mechanisms of the biological activity of plant complexes and mixtures determines the prospects for using metabolomic and biochemical methods to prolong active longevity.

The Effects of Antioxidants from Natural Products on Obesity, Dyslipidemia, Diabetes and Their Molecular Signaling Mechanism

Obesity is a risk factor that leads to the development of other diseases such as dyslipidemia and diabetes. These three metabolic disorders can occur simultaneously, hence, the treatment requires many drugs. Antioxidant compounds have been reported to have activities against obesity, dyslipidemia and diabetes via several mechanisms. This review aims to discuss the antioxidant compounds that have activity against obesity, dyslipidemia and diabetes together with their molecular signaling mechanism. The literature discussed in this review was obtained from the PUBMED database. Based on the collection of literature obtained, antioxidant compounds having activity against the three disorders (obesity, dyslipidemia and diabetes) were identified. The activity is supported by various molecular signaling pathways that are influenced by these antioxidant compounds, further study of which would be useful in predicting drug targets for a more optimal effect. This review provides insights on utilizing one of these antioxidant compounds as opposed to several drugs. It is hoped that in the future, the number of drugs in treating obesity, dyslipidemia and diabetes altogether can be minimized consequently reducing the risk of side effects.

The innate immune system and fever under redox control: A Narrative Review

ABSTRACT:

In living cells, redox potential is vitally important for normal physiological processes that are closely regulated by antioxidants, free amino acids and proteins that either have reactive oxygen and nitrogen species capture capability or can be compartmentalized. Although hundreds of experiments support the regulatory role of free radicals and their derivatives, several authors continue to claim that these perform only harmful and non-regulatory functions. In this paper we show that countless intracellular and extracellular signal pathways are directly or indirectly linked to regulated redox processes. We also briefly discuss how artificial oxidative stress can have important therapeutic potential and the possible negative effects of popular antioxidant supplements.

The impact of concurrent training and antioxidant supplementation on the factors associated with the ocular lens opacity in diabetic rats

The current study was aimed to investigate the protective effect of vitamins C and E (VCE) supplementation, exercise, and their concurrent application against cataract incidence in the diabetic rats. The obtained results indicated that different supplementation and training treatments were capable to preserve the lens transparency in the diabetic rats. Also, upon applying different supplementation and training treatments, the level of glutathione (GSH) and activity of antioxidant enzymes in the diabetic rats was preserved approximately close to their control levels. In addition, different treatments were capable to maintain the structural integrity of the lens proteins in diabetic rats. Moreover, VCE supplementation, exercise and their simultaneous application prevented lens crystallins of diabetic rats against fibrillation and formation of the increased oligomeric sizes. The results of this study signify the importance of antioxidant supplementation and exercise in reducing the detrimental effects of hyperglycemia on the eye lenses.

Potential Mechanisms Involved in the Protective Effect of Dicaffeoylquinic Acids from Artemisia annua L. Leaves against Diabetes and Its Complications

Diabetes mellitus is a chronic disease affecting the globe and its incidence is increasing pandemically. The use of plant-derived natural products for diabetes management is of great interest. Polar fraction of Artemisia annua L. leaves has shown antidiabetic activity in vivo. In the present study, three major compounds were isolated from this polar fraction; namely, 3,5-dicaffeoylquinic acid (1); 4,5-dicaffeoylquinic acid (2), and 3,4- dicaffeoylquinic acid methyl ester (3), using VLC-RP-18 and HPLC techniques. The potential protective effects of these compounds against diabetes and its complications were investigated by employing various in vitro enzyme inhibition assays. Furthermore, their antioxidant and wound healing effectiveness were evaluated. Results declared that these dicaffeoylquinic acids greatly inhibited DPPIV enzyme while moderately inhibited α-glucosidase enzyme, where compounds 1 and 3 displayed the most prominent effects. In addition, compound 3 showed pronounced inhibition of α-amylase enzyme. Moreover, these compounds markedly inhibited aldose reductase enzyme and exerted powerful antioxidant effects, among which compound 3 exhibited the highest activity implying a notable potentiality in impeding diabetes complications. Interestingly, compounds 2 and 3 moderately accelerated scratch wound healing. Our findings suggest that these dicaffeoylquinic acids can be promising therapeutic agents for managing diabetes and its complications.

Polyphenols and ω-3 PUFAs: Beneficial Outcomes to Obesity and Its Related Metabolic Diseases

Obesity is associated with the leading causes of death in the worldwide. On the other hand, the intake of vegetables, fruits and fish is related to the reduction of obesity and other metabolic syndromes. This review aims to highlight the role of ingestion of polyphenols and omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in reducing obesity and related metabolic diseases (RMDs). The consumption of vegetables, fish and by-products rich in polyphenols and α-linolenic acid (ALA), as well as oils rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with a decrease in obesity and its RMDs in consumers. Furthermore, we discussed the adequate amount of extracts, powder, polyphenols, ω-3 PUFAs administrated in animal models and human subjects, and the relevant outcomes obtained. Thus, we appeal to the research institutions and departments of the Ministries of Health in each country to develop a food education joint project to help schools, businesses and families with the aim of reducing obesity and other metabolic diseases.

Irisin in atherosclerosis

Irisin, a novel exercise-induced myokine, has been shown to play important roles in increasing white adipose tissue browning, regulating energy metabolism and improving insulin resistance. Growing evidence suggests a direct role for irisin in preventing atherosclerosis (AS) by inhibiting oxidative stress, improving dyslipidemia, facilitating anti-inflammation, reducing cellular damage and recovering endothelial function. In addition, some studies have noted that serum irisin levels play an essential role in cardiovascular diseases (CVDs) risk prediction, highlighting that irisin has the potential to be a useful predictive marker and therapeutic target of AS, especially in monitoring therapeutic efficacy. This review summarizes the understanding of irisin-mediated regulation in essential biological pathways and functions in atherosclerosis and prompts further exploitation of the biological properties of irisin in the pathogenesis of atherosclerosis.

Barks of Three Wild Pyrus Taxa: Phenolic Constituents, Antioxidant Activity, and in Vitro and in Silico Investigations of α-Amylase and α-Glucosidase Inhibition

Dry MeOH extracts of the twig barks of Pyrus communis subsp. pyraster, P. spinosa and their hybrid P.×jordanovii nothosubsp. velenovskyi, collected in wild in Serbia, were analyzed. By LC/MS, the contents of arbutin (99.9-131.0 mg/g), chlorogenic acid (2.2-6.3 mg/g), catechin (1.0-5.3 mg/g) and total dimeric and trimeric procyanidins (42.2-61.3 mg/g), including procyanidin B2 (8.9-17.2 mg/g), were determined. Colorimetrically, high contents of total phenolics (436.2-533.4 mg GAE/g) and tannins (339.4-425.7 mg GAE/g), as well as strong total antioxidant activities (FRAP values 4.5-5.9 mmol Fe²⁺ /g), and DPPH (SC₅₀ =6.6-7.1 μg/ml) and hydroxyl radical (SC₅₀ =447.1-727.7 μg/ml) scavenging abilities were revealed. In vitro, all extracts exhibited notable inhibition of α-amylase (IC₅₀ =310.8-617.7 μg/ml) and particularly strong inhibition of α-glucosidase (IC₅₀ =2.1-3.7 μg/ml). Molecular docking predicted that among identified compounds procyanidin B2 is the best inhibitor of these carbohydrate-digesting enzymes. Obtained results showed that the barks of investigated Pyrus hybrid and its parent taxa have similar composition and bioactivity.

Aging and the immune response in diabetic peripheral neuropathy

A large proportion of older individuals with diabetes go on to develop diabetic peripheral neuropathy (DPN). DPN is associated with an increase in inflammatory cells within the peripheral nerve, activation of nuclear factor kappa-light-chain-enhancer of activated B cells and receptors for advanced glycation end products/advanced glycation end products pathways, aberrant cytokine expression, oxidative stress, ischemia, as well as pro-inflammatory changes in the bone marrow; all processes that may be exacerbated with age. We review the immunological features of DPN and discuss whether age-related changes in relevant immunological areas may contribute to age being a risk factor for DPN.

Solanum anguivi Lam. Fruits: Their Potential Effects on Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder of glucose homeostasis associated with a status of insulin resistance, impaired insulin signaling, β-cell dysfunction, impaired glucose and lipid metabolism, sub-clinical inflammation, and increased oxidative stress. Consuming fruits and vegetables rich in phytochemicals with potential antidiabetic effects may prevent T2DM and/or support a conservative T2DM treatment while being safer and more affordable for people from low-income countries. Solanum anguivi Lam. fruits (SALF) have been suggested to exhibit antidiabetic properties, potentially due to the presence of various phytochemicals, including saponins, phenolics, alkaloids, ascorbic acid, and flavonoids. For the saponin fraction, antidiabetic effects have already been reported. However, it remains unclear whether this is also true for the other phytochemicals present in SALF. This review article covers information on glucose homeostasis, T2DM pathogenesis, and also the potential antidiabetic effects of phytochemicals present in SALF, including their potential mechanisms of action.

Potential Application of Some Lamiaceae Species in the Management of Diabetes

Diabetes is one of the most dangerous metabolic disorders, with high rates of mortality worldwide. Since ancient times, medicinal plants have been used in traditional medicine to treat many diseases, including diabetes and its related complications. Plants are widely accepted, affordable, and perceived to have minimal adverse side effects. The Lamiaceae family is a potential source of therapeutic agents for the management of metabolic disorders, including diabetes. Hence, this review paper summarizes the antidiabetic use of Lamiaceae species in folk medicine globally. Furthermore, we present the antidiabetic activities and phytochemical constituents of twenty-three (23) Lamiaceae species and the antidiabetic activity of some notable chemical constituents isolated from some of these Lamiaceae species.

Mediterranean Diet for the Prevention of Gestational Diabetes in the Covid-19 Era: Implications of Il-6 In Diabesity

The aim of this review is to highlight the influence of the Mediterranean Diet (MedDiet) on Gestational Diabetes Mellitus (GDM) and Gestational Weight Gain (GWG) during the COVID-19 pandemic era and the specific role of interleukin (IL)-6 in diabesity. It is known that diabetes, high body mass index, high glycated hemoglobin and raised serum IL-6 levels are predictive of poor outcomes in coronavirus disease 2019 (COVID-19). The immunopathological mechanisms of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection include rising levels of several cytokines and in particular IL-6. The latter is associated with hyperglycemia and insulin resistance and could be useful for predicting the development of GDM. Rich in omega-3 polyunsaturated fatty acids, vitamins, and minerals, MedDiet improves the immune system and could modulate IL-6, C reactive protein and Nuclear Factor (NF)-κB. Moreover, polyphenols could modulate microbiota composition, inhibit the NF-κB pathway, lower IL-6, and upregulate antioxidant enzymes. Finally, adhering to the MedDiet prior to and during pregnancy could have a protective effect, reducing GWG and the risk of GDM, as well as improving the immune response to viral infections such as COVID-19.

Reactive Oxygen Species and Antioxidants in Postharvest Vegetables and Fruits

Reducing oxidative species to non- or less-reactive matter is the principal function of an antioxidant. Plant-based food is the main external source of antioxidants that helps protect our cells from oxidative damage. During postharvest storage and distribution, fruits and vegetables often increase ROS production that is quenched by depleting their antioxidant pools to protect their cells, which may leave none for humans. ROS are molecules produced from oxygen metabolism; some of the most widely analyzed ROS in plants are singlet oxygen, superoxide, hydrogen peroxide, and hydroxyl radicals. ROS concentration and lifetime are determined by the availability and composition of the antioxidant system that includes enzymatic components such as SOD, CAT, and APX and nonenzymatic components such as vitamins, polyphenols, and carotenoid. Depending on its concentration in the cell, ROS can either be harmful or beneficial. At high concentrations, ROS can damage various kinds of biomolecules such as lipids, proteins, DNA, and RNA, whereas at low or moderate concentrations, ROS can act as second messengers in the intracellular signaling cascade that mediates various plant responses. Novel postharvest methods are sought to maintain fruit and vegetable quality, including minimizing ROS while preserving their antioxidant content.

Oral Nano Drug Delivery Systems for the Treatment of Type 2 Diabetes Mellitus: An Available Administration Strategy for Antidiabetic Phytocompounds

In view of the worldwide serious health threat of type 2 diabetes mellitus (T2DM), natural sources of chemotherapies have been corroborated as the promising alternatives, with the excellent antidiabetic activities, bio-safety, and more cost-effective properties. However, their clinical application is somewhat limited, because of the poor solubility, instability in the gastrointestinal tract (GIT), low bioavailability, and so on. Nowadays, to develop nanoscaled systems has become a prominent strategy to improve the drug delivery of phytochemicals. In this review, we primarily summarized the intervention mechanisms of phytocompounds against T2DM and presented the recent advances in various nanosystems of antidiabetic phytocompounds. Selected nanosystems were grouped depending on their classification and structures, including polymeric NPs, lipid-based nanosystems, vesicular systems, inorganic nanocarriers, and so on. Based on this review, the state-of-the-art nanosystems for phytocompounds in T2DM treatment have been presented, suggesting the preponderance and potential of nanotechnologies.

Oxidative stress mitigation by antioxidants - An overview on their chemistry and influences on health status

The present review paper focuses on the chemistry of oxidative stress mitigation by antioxidants. Oxidative stress is understood as a lack of balance between the pro-oxidant and the antioxidant species. Reactive oxygen species in limited amounts are necessary for cell homeostasis and redox signaling. Excessive reactive oxygenated/nitrogenated species production, which counteracts the organism's defense systems, is known as oxidative stress. Sustained attack of endogenous and exogenous ROS results in conformational and oxidative alterations in key biomolecules. Chronic oxidative stress is associated with oxidative modifications occurring in key biomolecules: lipid peroxidation, protein carbonylation, carbonyl (aldehyde/ketone) adduct formation, nitration, sulfoxidation, DNA impairment such strand breaks or nucleobase oxidation. Oxidative stress is tightly linked to the development of cancer, diabetes, neurodegeneration, cardiovascular diseases, rheumatoid arthritis, kidney disease, eye disease. The deleterious action of reactive oxygenated species and their role in the onset and progression of pathologies are discussed. The results of oxidative attack become themselves sources of oxidative stress, becoming part of a vicious cycle that amplifies oxidative impairment. The term antioxidant refers to a compound that is able to impede or retard oxidation, acting at a lower concentration compared to that of the protected substrate. Antioxidant intervention against the radicalic lipid peroxidation can involve different mechanisms. Chain breaking antioxidants are called primary antioxidants, acting by scavenging radical species, converting them into more stable radicals or non-radical species. Secondary antioxidants quench singlet oxygen, decompose peroxides, chelate prooxidative metal ions, inhibit oxidative enzymes. Moreover, four reactivity-based lines of defense have been identified: preventative antioxidants, radical scavengers, repair antioxidants, and those relying on adaptation mechanisms. The specific mechanism of a series of endogenous and exogenous antioxidants in particular aspects of oxidative stress, is detailed. The final section resumes critical conclusions regarding antioxidant supplementation.

Glucose-Uptake Activity and Cytotoxicity of Diterpenes and Triterpenes Isolated from Lamiaceae Plant Species

The prevalence of diabetes mellitus (DM), considered one of the most common metabolic disorders, has dramatically increased and resulted in higher rates of morbidity and mortality around the world in the past decade. It is well known that insulin resistance in target tissues and a deficiency in insulin secretion from pancreatic β-cells are the main characteristics of type 2 diabetes. The aim of this study was the bio-evaluation of compounds isolated from three selected plant species: namely, Salvia africana-lutea, Leonotis ocymifolia, and Plectranthus madagascariensis, for their glucose-uptake ability. Methanolic extracts were produced from the aerial parts of each plant. Compounds were identified using different spectroscopic techniques. The glucose-uptake ability of each compound was then evaluated in mammalian cells using 2-deoxyglucose-6-phosphate. The cytotoxicity of each compound was established via the MTT assay. Chromatographic purification of the three plant species yielded sixteen pure terpenoids. Compounds 1 (p = 0.0031), 8 (p = 0.0053), and 6 (p = 0.0086) showed a marked increase in glucose uptake, respectively. Additionally, 1, 4, and 6 exhibited cytotoxicity toward mammalian tissue with a decrease in cell viability of ~70%, ~68%, and ~67%, respectively. The results suggested that several compounds demonstrated a marked increase in glucose uptake, while two of the compounds exhibited signs of cytotoxicity. It may, therefore, be suggested that these compounds be considered as potential candidates for novel plant-derived alternative therapies in the treatment of type 2 diabetes.

Brazilian red propolis extract enhances expression of antioxidant enzyme genes in vitro and in vivo

Brazilian red propolis reportedly has reactive oxygen species (ROS) scavenging effects in vitro, but the cellular mechanisms remain unclear. In the present study, the effects of an ethanol extract of Brazilian red propolis (EERP) on the Nrf2-ARE intracellular antioxidant pathway were examined in vitro and in vivo. EERP and its constituents transactivated the reporter gene through the ARE sequence and enhanced the expression of Nrf2-regulated genes in HEK293 cells. It also increased Nrf2 protein in the nucleus, which was partially inhibited by kinase inhibitors. Furthermore, EERP suppressed ROS generation and cytotoxicity induced by tert-butyl hydroperoxide. In vivo, orally administered EERP increased the expression of Nrf2-regulated genes in mice liver. These results suggest that EERP is a potential resource for preventing oxidative stress-related diseases as an Nrf2 inducer.

Flavonoids modulate tight junction barrier functions in hyperglycemic human intestinal Caco-2 cells

OBJECTIVES

Diabetes mellitus is a chronic disease requiring lifelong medical attention. With hundreds of millions suffering worldwide and a rapidly rising incidence, diabetes mellitus poses a great burden on health care systems. Recent studies investigating the underlying mechanisms involved in disease development in diabetes point to the role of the dysregulation of the intestinal barrier. Hyperglycemia-mediated tight junction deformity is known to contribute to leaky gut in various metabolic disorders. The present study aimed to investigate the role of oxidative stress on intestinal epithelial tight junction (TJ) barrier functions in hyperglycemia. Because many flavonoids are known to influence the cellular redox state, exploring these flavonoids may help to understand the role of TJ barrier in hyperglycemia-mediated oxidative stress, which in turn might unfold the association of oxidative stress and dysfunction of barrier-forming TJs.

METHODS

Caco-2 cells were stimulated with high glucose (HG), with or without flavonoids (quercetin, morin, naringenin), for 24 h. We determined cellular viability, levels of reactive oxygen species, and mitochondrial membrane potential in flavonoids treated HG-Caco-2 cells. The levels of the proinflammatory cytokines, glucose uptake, and expression of glucose transporters were determined on flavonoids treatment. We investigated the effect of flavonoids on TJs functions by measuring transepithelial electrical resistance (a TJ integrity marker), membrane permeability using tracer compounds, and the expressions levels of TJs related molecules on hyperglycemic Caco-2 cell monolayers.

RESULTS

We found that high glucose treatment resulted in reduced cell viability, increased reactive oxygen species production, measurable mitochondrial dysfunction, and decreased transepithelial electrical resistance, with increased membrane permeability. Treatment with the test flavonoids produced increased cell viability and reduced glucose uptake of HG-Caco-2 cells. A concomitant decrease in reactive oxygen species production, proinflammatory cytokines, and Glut-associated genes and proteins were identified with flavonoid treatment. Flavonoids prevented derangement of TJs protein interaction and stabilized membrane permeability.

CONCLUSIONS

These findings indicate that flavonoids confer protection against hyperglycemia-mediated oxidative stress and enhance intestinal barrier functions by modulating underlying intracellular molecular mechanisms.

Aspalathin Protects Insulin-Producing β Cells against Glucotoxicity and Oxidative Stress-Induced Cell Death

SCOPE

Aspalathin, the main polyphenolic phytochemical of rooibos (Aspalathus linearis), has been attributed with health promoting properties, including a glucose lowering effect that can prove interesting for application as nutraceutical or therapeutic in (pre-)diabetics. Preservation of β cell mass in the pancreas is considered a key issue for diabetes prevention or treatment, therefore the aim is to investigate whether aspalathin also has β cell cytoprotective potential.

METHODS AND RESULTS

Rat pancreatic islets and the β cell line Insulinoma 1E (INS1E) are studied in vitro after exposure to various cytotoxic agents, namely streptozotocin (STZ), hydrogen peroxide, or chronic high glucose. The effect of aspalathin on cell survival and apoptosis is studied. Expression of relevant cytoprotective genes is analyzed by qRT-PCR and proteins by Western blot. Aspalathin is found to protect β cells against cytotoxicity and apoptosis. This is associated with increased translocation of nuclear factor erythroid 2-related factor 2 (NRF2) and expression of its antioxidant target genes heme oxygenase 1 (Hmox1), NAD(P)H quinone dehydrogenase 1 (Nqo-1), and superoxide dismutase 1 (Sod1).

CONCLUSION

It is proposed that aspalathin protects β cells against glucotoxicity and oxidative stress by increasing the expression of NRF2-regulated antioxidant enzymes. This indicates that aspalathin is an interesting β cell cytoprotectant.

Effect of Ficus glomerata leaf extract in streptozotocin-induced early diabetic complications and its characterization by LC-MS

Diabetes mellitus is a complex metabolic disorder that leads to various micro-vascular complications. The present study elucidated the effect of chloroform extract of leaves of Ficus glomerata (CHFG) in streptozotocin-induced early diabetic renal and neural complications. Wistar rats were injected with STZ (55 mg/kg, i.p.) to produce experimental diabetes. Two weeks after the stabilization of diabetes, CHFG extract at the dose of 200 and 400 mg/kg (CHFG 200 and CHFG 400) and metformin at the dose of 250 mg/kg (Met 250) was administered to the diabetic rats for further two weeks. Diabetic rats showed an increase in blood glucose, plasma urea, uric acid, creatinine, triglyceride, and total cholesterol level. The change in behavioral parameters such as thermal hyperalgesia and cold allodynia with compromised sciatic nerve and kidney antioxidant status were seen in diabetic rats. Diabetic rats treated with CHFG 200, CHFG 400, and Met 250 showed a decrease in blood glucose, plasma urea, uric acid, creatinine, triglyceride, and total cholesterol level. Also, it improved altered behavioral parameters such as thermal hyperalgesia and cold allodynia. It also restored the sciatic nerve and kidney antioxidant status. The results of kidney and sciatic nerves histopathological study were in line with the results of biochemical parameters that confirmed the favorable role of CHFG. Characterization of CHFG by LC-MS revealed the presence of diverse phytoconstituents, which might be responsible for its protective effect.

Protective effect of hydrogen sulfide on oxidative stress-induced neurodegenerative diseases

Hydrogen sulfide is an antioxidant molecule that has a wide range of biological effects against oxidative stress. Balanced oxidative stress is also vital for maintaining cellular function in biological system, where reactive oxygen species are the main source of oxidative stress. When the normal redox balance is disturbed, deoxyribonucleic acid, lipid, and protein molecules are oxidized under pathological conditions, like diabetes mellitus that leads to diabetic peripheral neuropathy. In diabetes mellitus-induced diabetic peripheral neuropathy, due to hyperglycemia, pancreatic beta cell (β cell) shows resistance to insulin secretion. As a consequence, glucose metabolism is disturbed in neuronal cells which are distracted from providing proper cell signaling pathway. Not only diabetic peripheral neuropathy but also other central damages occur in brain neuropathy. Neurological studies regarding type 1 diabetes mellitus patients with Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis have shown changes in the central nervous system because high blood glucose levels (HbA1c) appeared with poor cognitive function. Oxidative stress plays a role in inhibiting insulin signaling that is necessary for brain function. Hydrogen sulfide exhibits antioxidant effects against oxidative stress, where cystathionine β synthase, cystathionine γ lyase, and 3-mercaptopyruvate sulfurtransferase are the endogenous sources of hydrogen sulfide. This review is to explore the pathogenesis of diabetes mellitus-induced diabetic peripheral neuropathy and other neurological comorbid disorders under the oxidative stress condition and the anti-oxidative effects of hydrogen sulfide.

Almond-supplemented diet improves sexual functions beyond Phosphodiesterase-5 inhibition in diabetic male rats

Hyperglycemia, an important feature of diabetes, can cause oxidative stress, which is associated with varieties of diabetic complications including erectile dysfunction. Therefore, this study sought to investigate the effect of almond-supplemented diet on some biochemical indices relevant to erection in diabetic male rats. Forty-two male rats were divided into two groups: A (n = 6) and B (n = 36). Diabetes was induced in Group B via injection of a single dose of STZ (50 mg/kg) intraperitoneally and confirmed 72 h after induction. Diabetic rats (blood glucose ≥250 mg/dL) were subsequently divided into six groups (n = 6). Fourteen days after confirmation of diabetes, rats were fed with diets containing almond drupe and seeds (10 and 20% inclusion) for fourteen days. The effects of the diets on blood glucose, sexual behavior, sexual hormones, phosphodiesterase-5 activity, nitric oxide, H₂S, and AGEs levels were evaluated. Significant increase in blood glucose level, phosphodiesterase-5 activity, and glycated hemoglobin was observed in diabetic rats. Furthermore, diabetes caused a significant decrease in nitric oxide, H₂S, sexual hormones (testosterone, follicle-stimulating hormone and luteinizing hormone) levels, and sexual behavioral indices. However, treatment with diets supplemented with almond drupe and seeds significantly reversed these effects in diabetic rats. Findings in this study revealed that almond-supplemented diets enhance some important biomarkers relevant to erection in diabetic rats. Thus, dietary inclusion of almond (drupe and seeds) could serve as a cheap and readily available nutraceutical in the management of erectile dysfunction associated with diabetes.

The potential of Endophytic Fungal Extract Isolated from Cinnamon (Cinnamomum burmannii) as Antidiabetic and Antioxidant

An increase in blood glucose levels in people with diabetes can cause an increase in free radicals, which can worsen the disease. Thus, drugs that have antidiabetic and antioxidant activities are needed. The cinnamon plant is high in antioxidants and has long been used as a source for a diabetes drug. The utilization of endophytic fungi isolated from cinnamon plants as antidiabetic and antioxidant has never been reported. This study aims to investigate the antidiabetic as well as antioxidant activity from the extract of endophytic fungi from the cinnamon plant. The antidiabetic activity was tested using the α-glucosidase enzyme inhibition method, while antioxidant activity was tested using the DPPH free radical scavenging method. Total phenol content was measured based on the Follin-Ciocalteu reagent reaction. All endophytic fungal extracts from the cinnamon leaves, twigs, flowers, and fruit have antidiabetic and antioxidant activity as well as high total phenol content. The three parameters measured showed a positive correlation. Endophytic fungal extract of Cb.D6 isolate derived from the leaf had the highest antidiabetic and antioxidant activity among the other isolates amounting to 92.41% and 90.28%, respectively. In addition, the total phenol content of Cb.D6 isolates was also the highest with 357.83 mg equivalent to gallic acid/g extract. Therefore, the endophytic fungal extract of Cb.D6 isolate has the potential to be developed as a source of the antidiabetic and antioxidant ingredients.

Leucine-glycine and carnosine dipeptides prevent diabetes induced by multiple low-doses of streptozotocin in an experimental model of adult mice

AIMS/INTRODUCTION

Peptides are considered to be quasi-hormones and effective molecules for regulation of the cells function and prevention of metabolic disorders. Di- and tripeptides gastrointestinal absorption ability have been proposed to prevent diabetes progression.

MATERIALS AND METHODS

Small peptides with different sequences of specific amino acids were synthesized based on a solid phase peptide synthesis protocol, and carnosine (A) and glutathione were examined for the prevention of diabetes induced by multiple low-doses of streptozotocin in mice.

RESULTS

The peptides A, Leu-Gly (D) and Pro-Pro showed preventive effects on blood glucose elevation and impairment of the signaling and performance of β-cells. The β-cell function assessed by immunofluorescence and blood glucose level in mice exposed to diabetes treated by the peptides A and D was similar to the normal mice. The peptide D prevented bodyweight loss caused by diabetes induction. The use of D and A peptides dramatically prevented the incidence of disruption in β-cells signaling by maintaining the natural balance of intracellular Akt-2 and cyclic adenosine monophosphate.

CONCLUSIONS

The results proved that peptide D (Leu-Gly), named Hannaneh, inhibits the bodyweight loss caused by diabetes induction. The Hannaneh and carnosine dipeptides, with preservation of normal β-cell signaling and anti dipeptidyl peptidase-4 activity, prevented blood glucose increases in mice at risk of diabetes. These dipeptides might be regarded as the pharmaceutical agents for the prevention of diabetes.

Endothelium-Dependent Hyperpolarization (EDH) in Diabetes: Mechanistic Insights and Therapeutic Implications

Diabetes mellitus is one of the major risk factors for cardiovascular disease and is an important health issue worldwide. Long-term diabetes causes endothelial dysfunction, which in turn leads to diabetic vascular complications. Endothelium-derived nitric oxide is a major vasodilator in large-size vessels, and the hyperpolarization of vascular smooth muscle cells mediated by the endothelium plays a central role in agonist-mediated and flow-mediated vasodilation in resistance-size vessels. Although the mechanisms underlying diabetic vascular complications are multifactorial and complex, impairment of endothelium-dependent hyperpolarization (EDH) of vascular smooth muscle cells would contribute at least partly to the initiation and progression of microvascular complications of diabetes. In this review, we present the current knowledge about the pathophysiology and underlying mechanisms of impaired EDH in diabetes in animals and humans. We also discuss potential therapeutic approaches aimed at the prevention and restoration of EDH in diabetes.

Evaluation of in vivo antidiabetic, antidyslipidemic, and in vitro antioxidant activities of hydromethanolic root extract of Datura stramonium L. (Solanaceae)

BACKGROUND

The global morbidity and mortality rates of diabetes mellitus are persistently increasing. There is a demand for new antidiabetic drugs because the safety and efficacy of currently available medications are limited. The present study was therefore conducted to study the antidiabetic activities of the hydromethanolic root extract of Datura stramonium L. (Solanaceae) in mice.

METHODS

Blood glucose lowering activity of three doses (100, 200, and 400 mg/kg) of the hydromethanolic root extract of D. stramonium was tested on normoglycemic, oral glucose-loaded, and streptozotocin (STZ)-induced diabetic mice models. The effect of the extract on body weight and diabetic dyslipidemia was also studied on STZ-induced diabetic mice. Additionally, antioxidant activity of the plant extract was determined using 2,2-diphenyl-1-picrylhydrazine free radical scavenging assay. Data were analyzed using one way ANOVA followed by Tukey's post hoc multiple comparison test.

RESULTS

The hydromethanolic root extract did not show significant hypoglycemic activity in normoglycemic mice. The plant extract at doses of 100, 200, and 400 mg/kg significantly (P<0.05) reduced blood glucose levels of oral glucose-loaded and diabetic mice. All the three doses of the root extract significantly improved diabetic dyslipidemia and the body weight of diabetic mice. Free radical scavenging activity of the root extract was found to be comparable to ascorbic acid with an IC50 of 13.47 µg/mL.

CONCLUSION

This study demonstrated that the hydromethanolic root extract of D. stramonium possesses significant antidiabetic, antidyslipidemic, and antioxidant activities.

Effects of Parkia biglobosa aqueous seed extract on some biochemical, haematological and histopathological parameters in streptozotocin induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Parkia biglobosa seeds are used to treat diabetes and complications hence this study.

AIM

This study investigated the effects of Parkia biglobosa aqueous seed extract on some biochemical, haematological and histopathological indices in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Wistar rats of either sex (180-300 g) were fasted overnight and diabetes mellitus induced using streptozotocin 40 mg/kg IP. Diabetes mellitus (fasting blood glucose ≥ 200 mg/dl) was confirmed 48 h later. The rats were randomly grouped into six groups (n = 5): Group 1 (diabetic untreated control), group 2 (Parkia biglobosa 200 mg/kg), group 3 (Parkia biglobosa 400 mg/kg). group 4 (Parkia biglobosa 800 mg/kg), group 5 (glibenclamide 5 mg/kg as standard drug control) and group 6 (normoglycaemic control). They were treated daily. Acute toxicity study and phytochemical screening were also performed. Fourteen days later, they were sacrificed under chloroform anaesthesia. Vital organs (kidneys, liver and pancreas) and blood samples were obtained for histopathological, biochemical and haematological analysis.

RESULTS

Parkia biglobosa aqueous seed extract at the various doses caused significant (P < 0.05) elevations in red blood cell parameters in comparison to the diabetic control. The mean cell volume did not differ significantly from the diabetic control while 200 mg/kg and 400 mg/kg doses of the extract did not significantly modify the HCT levels. Treatment with Parkia biglobosa significantly (P < 0.05) lowered white blood cell and platelet counts in comparison to the diabetic control. Liver enzymes and total bilirubin levels were significantly (P < 0.05) reduced while total protein increased in the treated diabetic rats in comparison to controls. Treatment with Parkia biglobosa extract significantly (P < 0.05) increased bicarbonate and sodium ion levels while decreasing potassium ion levels. Chloride levels were not significantly different from the diabetic control.

CONCLUSION

These data suggest that Parkia biglobosa ameliorates biochemical, haematological and histopathological changes associated with diabetes mellitus.

Costus afer Protects Cardio-, Hepato-, and Reno-Antioxidant Status in Streptozotocin-Intoxicated Wistar Rats

Medicinal plants are efficient modulators of oxidative stress associated with diabetes mellitus. This study evaluated the cardio-, reno-, and hepato-antioxidant status of hydroethanolic extract of Costus afer on streptozotocin-intoxicated diabetic rats. Experimental animals were daily administered with hydroethanolic extract of C. afer by oral intubation for eight weeks (60 days), after which the levels of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and lipid peroxidation marker (MDA) were evaluated in the heart, liver, and kidney homogenates. Plasma biochemical parameters such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total protein, creatinine, and urea were determined. Meanwhile, parts of the heart, kidneys, and liver were histopathologically examined. Streptozotocin administration induced toxicity in the cardiac, hepatic, and renal tissues by stimulating significant increases (p<0.05) in the levels of CAT and SOD, GSH, and MDA. Similarly, significant increases (P<0.05) in the levels of ALT, AST, urea, and total protein were observed in streptozotocin treated rats, whereas decreases were observed in the levels of ALP, LDH, and creatinine. Following the treatments with C. afer hydroethanolic extract prevented the effect of streptozotocin by maintaining the tissue antioxidant status (CAT, SOD, GSH, and MDA) and the plasma biochemical parameters (AST, ALT, ALP, LDH, creatinine, and urea) towards the normal ranges. The histopathological examination revealed hepatovascular congestion and leucocyte infiltration as well as renovascular congestion, glomerulosclerosis, and tubular clarification in the untreated diabetic control and their absence in the group of animals treated with a high dose of C. afer extract. The findings of the present investigation suggest that C. afer possesses antioxidant activities capable of regulating drug induced tissue damage.

The Role of Natural Products in Targeting Cardiovascular Diseases via Nrf2 Pathway: Novel Molecular Mechanisms and Therapeutic Approaches

Cardiovascular diseases (CVDs) are closely linked to cellular oxidative stress and inflammation. This may be resulted from the imbalance generation of reactive oxygen species and its role in promoting inflammation, thereby contributing to endothelial dysfunction and cardiovascular complications. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a significant role in regulating expression of antioxidant and cytoprotective enzymes in response to oxidative stress. Natural products have emerged as a potential source of bioactive compounds which have shown to protect against atherogenesis development by activating Nrf2 signaling. This review aims to provide a comprehensive summary of the published data on the function, regulation and activation of Nrf2 as well as the molecular mechanisms of natural products in regulating Nrf2 signaling. The beneficial effects of using natural bioactive compounds as a promising therapeutic approach for the prevention and treatment of CVDs are reviewed.

Treatment of NASH with Antioxidant Therapy: Beneficial Effect of Red Cabbage on Type 2 Diabetic Rats

Aims

Oxidative stress (OS) plays a major role in type 2 diabetes and its vascular and hepatic complications, and novel therapeutic approaches include natural antioxidants. Our previous chemical and biological studies demonstrated the antioxidant activities of red cabbage (RC), and here, we aimed to determine the in vivo effects of 2-month long RC consumption using a high-fat/high-fructose model of diabetic rats.

Results

This vegetable, associated with lifestyle measurement, was shown to decrease OS and increase vascular endothelial NO synthase expression, ensuring vascular homeostasis. In the liver, RC consumption decreased OS by inhibiting p22phox expression and Nrf2 degradation and increasing catalase activity. It inhibited the activation of SREBP (1c, 2), ChREBP, NF-κB, ERK1/2, PPARγ, and GS and SIRT1 decrease, as observed in diabetic rats.

Conclusion/innovation

RC consumption led to metabolic profile improvement, together with hepatic function improvements. Although lifestyle changes are not sufficient to prevent diabetic complications, enrichment with RC avoids progression hepatic complications. This antioxidant strategy using RC does not only able to increase antioxidant defense, such as classical antioxidant, but also able to assure a metabolic and energetic balance to reverse complications. Whereas traditional medical therapy failed to reverse NASH in diabetic patients, consumption of RC should be a natural therapy to treat it.

Beneficial effects of cherry consumption as a dietary intervention for metabolic, hepatic and vascular complications in type 2 diabetic rats

Background

Oxidative stress (OS) plays an important role in type 2 diabetes (T2D) pathogenesis and its complications. New therapies target natural antioxidants as an alternative and/or supplemental strategy to prevent and control them. Our previous chemical and biological studies highlighted the important antioxidant activities of cherries, among other fruits and vegetables, thus we aimed to determine in vivo effects of 2-month long cherry consumption using a high-fat/high-fructose (HFHF) model of diabetic-rats (Lozano et al. in Nutr Metab 13:15, 2016).

Methods

After 2 months of HFHF, male Wistar rats were divided into: HFHF and HFHF enriched in cherry (nutritional approach) or standard diet ND (lifestyle measures) and ND plus cherry during 2 months. Metabolic, lipidic, oxidative parameters were quantified. Tissues (liver, pancreas and vessels) OS were assessed and hepatic (steatosis, fibrosis, inflammation) and vascular (endothelial dysfunction) complications were characterized.

Results

T2D was induced after 2 months of HFHF diet, characterized by systemic hyperglycaemia, hyperinsulinemia, glucose intolerance, dyslipidaemia, hyperleptinemia, and oxidative stress associated with endothelial dysfunction and hepatic complications. Cherry consumption for 2 months, in addition to lifestyle measures, in T2D-rats decreased and normalized the systemic disturbances, including oxidative stress complications. Moreover, in the vessel, cherry consumption decreased oxidative stress and increased endothelial nitric oxide (NO) synthase levels, thus increasing NO bioavailability, ensuring vascular homeostasis. In the liver, cherry consumption decreased oxidative stress by inhibiting NADPH oxidase subunit p22phox expression, nuclear factor erythroid-2 related factor 2 (Nrf2) degradation and the formation of reactive oxygen species. It inhibited the activation of sterol regulatory element-binding proteins (1c and 2) and carbohydrate-responsive element-binding protein, and thus decreased steatosis as observed in T2D rats. This led to the improvement of metabolic profiles, together with endothelial and hepatic function improvements.

Conclusion

Cherry consumption normalized vascular function and controlled hepatic complications, thus reduced the risk of diabetic metabolic disorders. These results demonstrate that a nutritional intervention with a focus on OS could prevent and/or delay the onset of vascular and hepatic complications related to T2D.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0744-6) contains supplementary material, which is available to authorized users.

Phytochemicals: Target-Based Therapeutic Strategies for Diabetic Retinopathy

Background: A variety of causative factors are involved in the initiation of diabetic retinopathy (DR). Current antidiabetic therapies are expensive and not easily accessible by the public. Furthermore, the use of multiple synthetic drugs leads to severe side effects, which worsen the diabetic patient’s condition. Medicinal plants and their derived phytochemicals are considered safe and effective treatment and their consumption can reduce the DR risk. In this article, we discuss a variety of medicinal plants, and their noteworthy bio-active constituents, that will be utilized as target based therapeutic strategies for DR. Methods: A broad-spectrum study was conducted using published English works in various electronic databases including Science Direct, PubMed, Scopus, and Google Scholar. Results: Targeting the multiple pathological factors including ROS, AGEs formation, hexosamine flux, PARP, PKC, and MAPK activation through variety of bioactive constituents in medicinal plants, diabetes progression can be delayed with improved loss of vision. Conclusions: Data reveals that traditional herbs and their prominent bioactive components control and normalize pathological cellular factors involved in DR progression. Therefore, studies should be carried out to explore the protective retinopathy effects of medicinal plants using experimental animal and humans models.