Relationship between hyperglycemia, antioxidant capacity and some enzymatic and non-enzymatic antioxidants in African patients with type 2 diabetes

Diabetic Encephalopathy: Role of Oxidative and Nitrosative Factors in Type 2 Diabetes

Diabetes mellitus is a set of complex metabolic disorders characterized by chronic hyperglycaemic condition due to defective insulin secretion (Type 1) and action (Type 2), which leads to serious micro and macro-vascular damage, inflammation, oxidative and nitrosative stress and a deranged energy homeostasis due to imbalance in the glucose and lipid metabolism. Moreover, patient with diabetes mellitus often showed the nervous system disorders known as diabetic encephalopathy. The precise pathological mechanism of diabetic encephalopathy by which it effects the central nervous system directly or indirectly causing the cognitive and motor impairment, is not completely understood. However, it has been speculated that like other extracerebellar tissues, oxidative and nitrosative stress may play significant role in the pathogenesis of diabetic encephalopathy. Therefore, the present review aimed to explain the possible association of the oxidative and nitrosative stress caused by the chronic hyperglycaemic condition with the central nervous system complications of the type 2 diabetes mellitus induced diabetic encephalopathy.

Total Antioxidant Capacity in Obese and Non-Obese Subjects and Its Association with Anthropo-Metabolic Markers: Systematic Review and Meta-Analysis

The total antioxidant capacity (TAC) has been related to the development of and complications associated with chronic diseases, but its importance during obesity is not entirely clear. We conducted a systematic review and meta-analysis to clarify whether there are differences or similarities in the TAC between subjects with obesity (SO) and subjects with normal weight (NW). Following the recommendations of PRISMA and Cochrane, we performed a systematic search in the PubMed, Scopus, Web of Science, Cochrane, and PROSPERO databases, identifying 1607 studies. Among these, 22 studies were included in the final analysis, comprising 3937 subjects (1665 SO and 2272 NW) in whom serum TAC was measured, and from these 19,201 subjects, the correlation of serum TAC with anthropo-metabolic parameters was also estimated. The Newcastle-Ottawa method was used for the evaluation of the risk of bias. Using a random-effect model (REM), TAC was reduced in SO independently of age (SMD, -0.86; 95% CI -1.38 to -0.34; p = 0.0012), whereas malondialdehyde (SMD, 1.50; 95% CI 0.60 to 2.41), oxidative stress index (SMD, 1.0; 95% CI 0.16 to 1.84), and total oxidant status (SMD, 0.80; 0.22 to 1.37) were increased. There were seven significant pooled correlations of TAC with anthropometric and metabolic parameters: weight (r = -0.17), hip circumference (r= -0.11), visceral adipose index (r = 0.29), triglycerides (r = 0.25), aspartate aminotransferase (r = 0.41), alanine aminotransferase (r = 0.38), and uric acid (r = 0.53). Our results confirm a decrease in TAC and an increase in markers of oxidative stress in SO and underpin the importance of these serum biomarkers in obesity.

Inverse Correlation of Superoxide Dismutase and Catalase with Type 2 Diabetes among Rural Thais

Oxidative stress contributes to defective antioxidant defenses, which may lead to type 2 diabetes (T2D). This study aimed to elucidate the T2D risks and antioxidant defenses by investigating the superoxide dismutase (SOD), catalase (CAT), vitamin A, and vitamin E status. We observed 102 participants aged 35-66 years from Sung Neon, Nakhon Ratchasima, Thailand. The blood samples were collected to measure the SOD, CAT, vitamin A, and vitamin E concentrations. The SOD and CAT activities were inversely associated with T2D risk. When compared with participants in the highest quartile of SOD and CAT, those in the lowest quartile for T2D risk obtained multivariable-adjusted odds ratios of 4.77 (SOD: 95% confident interval CI, 1.01-22.40; p = 0.047) and 4.22 (CAT: 95% CI, 1.07-16.60; p = 0.039). The possible influencing factors (e.g., physical activity, total cholesterol, and triglyceride) might mediate the association of SOD and CAT with T2D risk. Meanwhile, the relationship between vitamin A and vitamin E concentrations and T2D risk was insignificant. In conclusion, lower concentrations of antioxidant enzyme activity (SOD and CAT) may be an additional risk factor for T2D.

A systematic review and meta-analysis of randomized controlled trials investigating the effects of probiotics on oxidative stress in healthy adults

BACKGROUND

The oxidative stress (OS) theory of disease stipulates that a chronic imbalance in the ratio of oxidants to antioxidants in the cellular environment leads to a variety of debilitating conditions, including type 2 diabetes, cardiovascular and liver diseases. Metabolites in the gut microbiome have been associated with increases in reactive oxygen species (ROS). Many randomized controlled trials (RCTs) have thus investigated the potential of probiotics as a nutraceutical intervention to improve parameters of OS.

AIM

The objective of this paper is to review relevant human RCTs exploring the potential of probiotic supplementation to prevent OS in metabolically healthy individuals.

METHODS

This systematic review and meta-analysis was registered on PROSPERO (CRD42021297210). The PubMed database was searched using keywords related to probiotics and OS. In total, out of the 652 studies were screened, 9 respected the inclusion criteria.

RESULTS

Total antioxidant capacity (TAC) (SMD: 0.83 mmol/L, 95% CI: 0.25-1.40, p = 0.005) and glutathione (GSH) (SMD: 0.45, 95% CI: 0.13-0.77, p = 0.006) are improved with probiotic ingestion, although there are no alterations in superoxide dismutase (SOD) (SMD: 0.33, 95% CI: -0.27-0.93, p = 0.28). Decreases in plasma concentrations of the OS biomarker malondialdehyde (MDA) (SMD: -0.55, 95% CI: -1.11-0.00, p = 0.05) are also detected.

CONCLUSION

Probiotics improve AS and OS in metabolically healthy individuals. However, more studies are needed to address the moderate to high degree of heterogeneity in methodology.

Metabolite Profiling, Antioxidant and Key Enzymes Linked to Hyperglycemia Inhibitory Activities of Satureja hispidula: An Underexplored Species from Algeria

In the present study, two extracts from the aerial parts of the endemic species Satureja hispidula were analyzed for the first time by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS) method in order to identify and quantify their phenolic compounds. These extracts' antioxidant, α-glucosidase and α-amylase inhibitory activities were also evaluated. UHPLC-DAD-ESI/MS allowed the identification of 28 and 20 compounds in the ethanolic and aqueous extracts, respectively; among them, 5-O-caffeoylquinic acid was the most abundant in both extracts. The biological assay results indicate that the species S. hispidula, besides its high antioxidant power, is also potentially useful for inhibiting the α-glucosidase enzyme. In both antioxidant and α-glucosidase inhibitory assays, the aqueous extract exhibited the most promising results, significantly better than the standards used as positive controls.

Accelerated Senescence and Apoptosis in the Rat Liver during the Progression of Diabetic Complications

Background

Chronic hyperglycaemia of diabetes causes long-term damage and impaired function of multiple organs. However, the pathological changes in the liver following long-term diabetes remain unclear. This study aimed to determine the pathological complications of long-term diabetes in the rat liver.

Methods

Intraperitoneal injection of streptozotocin (STZ) was used to induce diabetes in rats at a single dose (60 mg/kg body weight [BW]). Rats were euthanised at 1 month (DM1 group), 2 months (DM2 group) and 4 months (DM4 group) following diabetes induction with six rats in each group. Immunohistochemistry was performed against SOD1, CD68, p53 and p16 antibodies. Messenger RNA (mRNA) expressions of SOD1, SOD2, GPx, CD68, p53, p21 and caspase-3 genes were measured by reverse transcription-polymerase chain reaction.

Results

Hepatic p53 mRNA expression was significantly higher in DM1, DM2 and DM4 groups compared to the control group. The p21 and caspase-3 mRNA expressions were significantly upregulated in the DM2 and DM4 groups. The p16-positive cells were obviously increased, particularly in the DM4 group. Bivariate correlation analysis showed mRNA expressions of p21 and caspase-3 genes were positively correlated with the p53 gene.

Conclusion

Diabetic rats exhibited increased apoptosis and senescence in the liver following a longer period of hyperglycaemia.

Glutathione Peroxidase 4 Is a Predictor of Diabetic Kidney Disease Progression in Type 2 Diabetes Mellitus

BACKGROUND

Diabetic kidney disease (DKD) represents a heavy burden in type 2 diabetes mellitus (T2DM). Ferroptosis plays an important role in DKD, and it thus provides new perspectives to pursue more related biomarkers to assess the disease severity and prognosis. Glutathione peroxidase 4 (GPX4) is the mainstay in regulating ferroptosis. The current study investigated the predictive value of kidney GPX4 expression level in DKD progression.

METHODS

We measured GPX4 levels in kidney paraffin sections of 85 biopsy-proven DKD patients by immunohistochemistry staining. The associations between the GPX4 level and clinicopathological parameters as well as renal outcomes were analyzed.

RESULTS

GPX4 is mainly expressed in kidney tubulointerstitium, especially in tubular epithelial cells of DKD patients. The GPX4 expression level was significantly lower in DKD patients than healthy controls. Besides, GPX4 level significantly correlated with proteinuria (r = -0.42, p < 0.001), urinary albumin-to-creatinine ratio (uACR) (r = -0.40, p < 0.01), serum creatinine (Scr) (r = -0.59, p < 0.001), estimated glomerular filtration rate (eGFR) (r = 0.66, p < 0.001), and the percentage of sclerosed glomeruli (r = -0.42, p < 0.001) in renal specimens. During follow-up, the GPX4 level positively correlated with eGFR slope (r = 0.48, p < 0.001), and GPX4-low patients showed a significantly higher probability of developing end-stage kidney disease (ESKD) compared with GPX4-high patients (p < 0.01). Moreover, after adjusting for other potential predictors, the GPX4 level was still an independent predictor of developing ESKD (HR 2.15, 95% CI 1.08 to 4.28, p < 0.05).

CONCLUSIONS

Kidney tubulointerstitial GPX4 expression level was associated with the disease severity and progression of DKD.

The Correlation of Signal to Noise Ratio Value on DPOAE with Malondialdehyde Levels in Rattus Norvegicus Diabetes Model

Introduction

The aim of this study was to determine the correlation of the signal-to-noise ratio (SNR) value on distortion product otoacoustic emissions (DPOAE) examination with malondialdehyde (MDA) levels in a diabetic rat model.

Materials and Methods

The subjects of this study were 25 rats. The samples were divided into 5 groups (days of confirmed diabetes): group 1 (control/non-treatment); group 2 (3 days); group 3 (6 days); group 4 (9 days); and group 5 (12 days). Samples that confirmed diabetes were assessed by DPOAE examination and subjected to MDA-level examination. The data were processed using SPSS and considered significant if p <0.05.

Results

The study showed a decrease in SNR values and an increase in MDA levels for the rats, which was confirmed by diabetes. The most significant result was shown by group 5, which compared to the other diabetes groups. A post hoc test showed the significant difference SNR value in each group (p<0.05); except for groups 1 and 2, the MDA levels showed significant differences for all groups. The Pearson correlation test showed a negative correlation between SNR values and MDA levels. A significant correlation between SNR values and MDA levels was found in group 5.

Conclusions

The study showed a correlation of SNR values from DPOAE examination to MDA levels in diabetes rats, indicating that there has been tissue damage (cochlea), which is characterized by a decrease in the SNR value.

Antioxidative, Anti-Inflammatory, Anti-Obesogenic, and Antidiabetic Properties of Tea Polyphenols-The Positive Impact of Regular Tea Consumption as an Element of Prophylaxis and Pharmacotherapy Support in Endometrial Cancer

Endometrial cancer (EC) is second only to cervical carcinoma among the most commonly diagnosed malignant tumours of the female reproductive system. The available literature provides evidence for the involvement of 32 genes in the hereditary incidence of EC. The physiological markers of EC and coexisting diet-dependent maladies include antioxidative system disorders but also progressing inflammation; hence, the main forms of prophylaxis and pharmacotherapy ought to include a diet rich in substances aiding the organism’s response to this type of disorder, with a particular focus on ones suitable for lifelong consumption. Tea polyphenols satisfy those requirements due to their proven antioxidative, anti-inflammatory, anti-obesogenic, and antidiabetic properties. Practitioners ought to consider promoting tea consumption among individuals genetically predisposed for EC, particularly given its low cost, accessibility, confirmed health benefits, and above all, suitability for long-term consumption regardless of the patient’s age. The aim of this paper is to analyse the potential usability of tea as an element of prophylaxis and pharmacotherapy support in EC patients. The analysis is based on information available from worldwide literature published in the last 15 years.

Oxidative Stress in Malaria: Potential Benefits of Antioxidant Therapy

Malaria is an infectious disease and a serious public health problem in the world, with 3.3 billion people in endemic areas in 100 countries and about 200 million new cases each year, resulting in almost 1 million deaths in 2018. Although studies look for strategies to eradicate malaria, it is necessary to know more about its pathophysiology to understand the underlying mechanisms involved, particularly the redox balance, to guarantee success in combating this disease. In this review, we addressed the involvement of oxidative stress in malaria and the potential benefits of antioxidant supplementation as an adjuvant antimalarial therapy.

Helichrysum Genus and Compound Activities in the Management of Diabetes Mellitus

The global management of diabetes mellitus (DM) involves the administration of recommended anti-diabetic drugs in addition to a non-sedentary lifestyle upon diagnosis. Despite the success recorded from these synthetic drugs, the traditional method of treatment using medicinal plants is increasingly accepted by the locals due to its low cost and the perceived no side effects. Helichrysum species are used in folk medicine and are documented for the treatment of DM in different regions of the world. This study reviews Helichrysum species and its compounds’ activities in the management of DM. An extensive literature search was carried out, utilizing several scientific databases, ethnobotanical books, theses, and dissertations. About twenty-two Helichrysum species were reported for the treatment of diabetes in different regions of the world. Among these Helichrysum species, only fifteen have been scientifically investigated for their antidiabetic activities, and twelve compounds were identified as bioactive constituents for diabetes. This present review study will be a useful tool for scientists and health professionals working in the field of pharmacology and therapeutics to develop potent antidiabetic drugs that are devoid of side effects.

Three minutes of moderate-intensity stair walking improves glucose and insulin but not insulin sensitivity or total antioxidant capacity

BACKGROUND AND AIMS

This study examined the effect of moderate intensity stair stepping exercise on the glycemic response, and antioxidant capacity (TAC) during an oral glucose tolerance test (OGTT).

METHODS AND RESULTS

Thirty participants (women = 12) completed 4 OGTTs during rest or stair walking bouts of 1, 3, and 10 min in a randomized order. Blood was collected at baseline and 30 min during the OGTTs and analyzed for glucose, insulin, TAC, and lactate. Glucose concentrations were decreased following the 10 min (-22.69 (-34.66 to -10.72) mg/dL, p < 0.002) and 3 min (-15.37 (-25.05 to -5.69) mg/dL, p < 0.004) bouts but not the 1 min bout (-6.18 (-19.54 to 7.18) mg/dL, p = 0.352). Insulin concentrations were decreased following the 10 min (-6.11 (-8.86 to -3.36 μIU/dL), p < 0.001) and 3 min (-2.589 (-4.54 to -0.63) μIU/dL, p < 0.012) bouts but not the 1 min bout (-0.37 (-1.87 to 1.13) μIU/dL, p = 0.616). Insulin sensitivity index values showed a significant increase in the 10-min trial (1.81 (0.03-3.58), p < 0.048), but not during the 3 min (0.65 (-0.66 to 1.96) p = 0.317) or 1 min trial (0.13 (-1.58 to 1.84) p = 0.878). There was no omnibus effect for trial in TAC (p = 0.132, η² = 0.07). There was no interaction between trial and time for blood lactate (p = 0.621, η² = 0.02).

CONCLUSION

This study provides evidence bouts as short as 3 min decrease postprandial blood glucose and insulin levels but longer bouts are needed to affect insulin sensitivity.

The effects of supplementation of Nannochloropsis oculata microalgae on biochemical, inflammatory and antioxidant responses in diabetic rats

Diabetes is accompanied by inflammation and oxidation. Supplementation of anti-inflammatory and antioxidant compounds can prevent the progression of diabetes. This study aimed to investigate the effects of supplementation of Nannochloropsis oculata microalgae (NOM) on the inflammatory and antioxidant responses in diabetic rats. Sixty male rats were divided into six groups as diabetic and non-diabetic rats receiving 0, 10 and 20 mg/kg of body weight of NOM daily for 21 days. Body weight, the serum concentrations of insulin and glucose and the tissue concentrations of interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), interleukin-6 (IL-6), malondialdehyde (MDA), ferric reducing antioxidant power (FRAP), superoxide dismutase (SOD), glutathione peroxidase (GPx) were assessed. The results showed that induction of diabetes significantly reduced the body weight, the serum concentrations of insulin and the tissue concentrations of SOD, FRAP and GPx while increasing the concentrations of glucose, MDA, IL-1β, IL-6, NF-κB and TNF-α. Daily oral administration of NOM (10 and 20 mg/kg) significantly maintained the body weight, the serum concentrations of insulin and the tissue concentrations of SOD, FRAP and GPx while preventing the increase in the concentrations of glucose, MDA, IL-1β and TNF-α. In conclusion, diabetes caused inflammation and oxidation while NOM worked as a natural anti-inflammatory and antioxidant compound.

Insect (black soldier fly larvae) oil as a potential substitute for fish or soy oil in the fish meal-based diet of juvenile rainbow trout (Oncorhynchus mykiss)

Alternative sources of fish oil (FO) are one of the major problems in aquaculture; therefore, the goal of the present study was to examine insect (black soldier fly larvae) oil (BSLO) as a potential replacer of fish/soy oil in juvenile rainbow trout (initial average weight of 32 ± 0.15 g) feed. Four diets were formulated wherein FO (control diet) was completely replaced with either soybean oil (SO) or BSLO, and an additional BSLO-based diet supplemented with 1.5% bile acid (BSLO + BA) were fed to the fish for 10 weeks. Growth performance of the BSLO fed group was similar (P > 0.05) to that of the FO and SO fed groups, however, the fish fed BSLO + BA diet registered the lowest growth (P < 0.05). Oil sources did not (P > 0.05) affect the major nutrient content of whole-body, however, the fatty acid composition of the muscle and liver was influenced (P < 0.05), with the highest 14:0, 16:0, and total saturated fatty acid detected in BSLO or BSLO + BA fed trout compared to the others (P < 0.001). No significant differences were observed in eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) or total n-3 polyunsaturated fatty acid (PUFA) content in muscle among the groups, whereas, the highest EPA:DHA and n-3:n-6 ratios were detected in the FO group. Gene expression for fatty acid binding protein (fabp), fatty acid synthase (fas), and Δ5 desaturase in the liver was lower in FO (P < 0.05), while BSLO + BA registered the highest Δ6 expression (P = 0.006). Supplementation of BA in the BSLO diet increased superoxide dismutase (SOD) and catalase (CAT) activities compared to the other groups (P < 0.05). In conclusion, BSLO could serve as a substitute for FO and SO in rainbow trout diet without negatively impacting growth performance, whole-body composition and nutrient retention, and modulate the expression of fatty acid metabolism-related genes in rainbow trout.

Antioxidant, Anti-Inflammatory, and Immunomodulatory Properties of Tea-The Positive Impact of Tea Consumption on Patients with Autoimmune Diabetes

The physiological markers of autoimmune diabetes include functional disorders of the antioxidative system as well as progressing inflammation and the presence of autoantibodies. Even though people with type 1 diabetes show genetic predispositions facilitating the onset of the disease, it is believed that dietary factors can stimulate the initiation and progression of the disease. This paper analyses the possibility of using tea as an element of diet therapy in the treatment of type 1 diabetes. Based on information available in literature covering the last 10 years, the impact of regular tea consumption or diet supplements containing tea polyphenols on the oxidative status as well as inflammatory and autoimmune response of the organism was analyzed. Studies conducted on laboratory animals, human patients, and in vitro revealed positive effects of the consumption of tea or polyphenols isolated therefrom on the diabetic body. Few reports available in the literature pertain to the impact of tea on organisms affected by type 1 diabetes as most (over 85%) have focused on cases of type 2 diabetes. It has been concluded that by introducing tea into the diet, it is possible to alleviate some of the consequences of oxidative stress and inflammation, thus limiting their destructive impact on the patients' organisms, consequently improving their quality of life, regardless of the type of diabetes. Furthermore, elimination of inflammation should reduce the incidence of immune response. One should consider more widespread promotion of tea consumption by individuals genetically predisposed to diabetes, especially considering the drink's low price, easy availability, overall benefits to human health, and above all, the fact that it can be safely used over extended periods of time, regardless of the patient's age.

Histological and biochemical investigation of the renoprotective effects of metformin in diabetic and prostate cancer model

BACKGROUND

Diabetes and cancer have common physiological and biochemical mechanisms. Metformin is the preferred drug of choice for the treatment of diabetes. Prostate cancer can be modeled in by injection of MAT-Lylu cells. A model of diabetes in rats is induced by streptozotocin injectıon. In the current study, we explored the mechanisms by which diabetes accelerates cancer, and evaluated the effects of metformin to know whether it has any impact against the damage caused by cancer and diabetic + cancer via histopathological and biochemical parameters of kidney tissue.

METHODS

The experiment was carried out in rats. Groups 1-Control, 2- Diabetic, 3-Cancer, 4-Diabetic + cancer, 5-Diabetic + cancer + metformin, 6-Cancer + metformin. Metformin treatment was applied by gavage every day. The research ended on the 14th day. The collected kidney tissue sections were stained with Hematoxylin-Eosin.

RESULTS

Histological evaluation showed moderate to severe damage to the kidney tissue following diabetic and cancer processess. In diabetic, cancer and diabetic + cancer groups, reduced glutathione levels, total antioxidant status, sodium/potassium-ATPase and paraoxonase1 activities were found to be significantly abated. While advanced oxidized protein products, lipid peroxidation, nitric oxide, tumor necrosis factor-alpha, reactive oxygen species levels, total oxidant status, catalase, superoxide dismutase, glutathione-related antioxidant enzymes, myeloperoxidase, and arginase activities were significantly raised. The administration of metformin reversed these defects. The outcome of the reveals that histopathological and biochemical damage in cancer and diabetes + cancer groups decreased in the groups that received metformin.

CONCLUSION

In conclusion, metformin treatment can be considered an adjuvant candidate for kidney tissue in diabetes, prostate cancer and cancer therapy related damage.

The antioxidant and anti-inflammatory effects of astaxanthin supplementation on the expression of miR-146a and miR-126 in patients with type 2 diabetes mellitus: A randomised, double-blind, placebo-controlled clinical trial

BACKGROUND

The pathogenesis of type 2 diabetes mellitus (T2DM) is associated with chronic oxidative stress and inflammation. It is well known that the expression of some miRNAs such as miRNA-146a is upregulated in diabetic and hyperglycaemic patients, whereas circulating miRNA-126 is reduced. Therefore, we aimed to determine the effects of astaxanthin (AST) supplementation on the circulating malondialdehyde (MDA) and interleukin 6 (IL-6) levels, and the expression of miR-146a and miR-126 in patients with T2DM.

METHODS

This randomised, double-blind, placebo-controlled clinical trial was conducted in 44 patients with T2DM randomly receiving 8 mg/d of oral AST (n = 22) or placebo (n = 22) for 8 weeks.

RESULTS

We observed that AST supplementation could decrease plasma levels of MDA and IL-6 (P < .05) and decrease the expression level of miR-146a over time (fold change: -1/388) (P < .05).

CONCLUSION

AST supplementation might be beneficial for improving circulating MDA and IL-6 and the down-regulation of miR-146a. However, future investigations are suggested to confirm these results.

Common and Novel Markers for Measuring Inflammation and Oxidative Stress Ex Vivo in Research and Clinical Practice-Which to Use Regarding Disease Outcomes?

Many chronic conditions such as cancer, chronic obstructive pulmonary disease, type-2 diabetes, obesity, peripheral/coronary artery disease and auto-immune diseases are associated with low-grade inflammation. Closely related to inflammation is oxidative stress (OS), which can be either causal or secondary to inflammation. While a low level of OS is physiological, chronically increased OS is deleterious. Therefore, valid biomarkers of these signalling pathways may enable detection and following progression of OS/inflammation as well as to evaluate treatment efficacy. Such biomarkers should be stable and obtainable through non-invasive methods and their determination should be affordable and easy. The most frequently used inflammatory markers include acute-phase proteins, essentially CRP, serum amyloid A, fibrinogen and procalcitonin, and cytokines, predominantly TNFα, interleukins 1β, 6, 8, 10 and 12 and their receptors and IFNγ. Some cytokines appear to be disease-specific. Conversely, OS-being ubiquitous-and its biomarkers appear less disease or tissue-specific. These include lipid peroxidation products, e.g., F2-isoprostanes and malondialdehyde, DNA breakdown products (e.g., 8-OH-dG), protein adducts (e.g., carbonylated proteins), or antioxidant status. More novel markers include also -omics related ones, as well as non-invasive, questionnaire-based measures, such as the dietary inflammatory-index (DII), but their link to biological responses may be variable. Nevertheless, many of these markers have been clearly related to a number of diseases. However, their use in clinical practice is often limited, due to lacking analytical or clinical validation, or technical challenges. In this review, we strive to highlight frequently employed and useful markers of inflammation-related OS, including novel promising markers.

Effects of 4-phenylbutyric acid on the development of diabetic retinopathy in diabetic rats: regulation of endoplasmic reticulum stress-oxidative activation

There are good evidences suggesting that endoplasmic reticulum (ER) stress can be one of the contributing factors in the development of diabetic retinopathy. The present study was designed to investigate the effect of chemical chaperone 4-phenylbutyric acid (4-PBA) in alleviating the ER stress, and diabetic retinopathy in type 2 diabetic rats. Treatment of diabetic rats with 4-PBA, increased the antioxidant capacity, reduced the levels of lipid peroxidation, organised the state of apoptosis and regulated the ER stress - oxidative activation in retinal tissue. Also there was an improvement in the histological picture of retinal specimens compared to untreated diabetic rats. It was concluded that 4-PBA is a promising therapeutic agent for ER stress diseases such as diabetic retinopathy.

The effect of tropisetron on oxidative stress, SIRT1, FOXO3a, and claudin-1 in the renal tissue of STZ-induced diabetic rats

Tropisetron is a 5-HT3 receptor antagonist that exerts protective effect against DN. The aim of this study was to investigate the possible molecular mechanisms associated with the renoprotective effects of tropisetron in STZ-induced diabetic rats. Animals were subdivided into 5 equal groups; control, tropisetron, diabetes, tropisetron + diabetes, and glibenclamide + diabetes (n = 7). For induction of type 1 diabetes, a single injection of STZ (55 mg/kg, i.p.) was administered to the animals. Diabetic rats were treated with tropisetron (3 mg/kg) and glibenclamide (1 mg/kg) for 2 weeks. According to the conducted analysis, diabetes led to renal dysfunction (reduction in glomerular filtration rate and urine urea and creatinine as well as elevation in plasma urea and creatinine) and abnormalities in antioxidant defense system (reduction in TAC and elevation in MDA), compared with the control group, which was prevented by tropisetron treatment. Reverse transcription-quantitative polymerase chain reaction and western blotting analysis demonstrated that SIRT1 gene expression decreased while FOXO3a and NF-κB gene expression as well as phosphorylated FOXO3a/total FOXO3a protein ratios and claudin-1 protein level increased in the kidney of diabetic rats compared with the control group. Herein, the results of this research showed that tropisetron treatment reversed these changes. Besides, all these changes were comparable with those produced by glibenclamide as a positive control. Hence, tropisetron ameliorated renal damage due to diabetic nephropathy possibly by suppressing oxidative stress and alteration of SIRT1, FOXO3a, and claudin-1 levels.

Bariatric Surgery Normalizes Protein Glycoxidation and Nitrosative Stress in Morbidly Obese Patients

The results of recent studies indicate the key role of nitrosative stress and protein oxidative damage in the development of morbid obesity. Nevertheless, the effect of bariatric surgery on protein oxidation/glycation and nitrosative/nitrative stress is not yet known. This is the first study evaluating protein glycoxidation and protein nitrosative damage in morbidly obese patients before and after (one, three, six and twelve months) laparoscopic sleeve gastrectomy. The study included 50 women with morbid obesity as well as 50 age- and gender-matched healthy controls. We demonstrated significant increases in serum myeloperoxidase, plasma glycooxidative products (dityrosine, kynurenine, N-formyl-kynurenine, amyloid, Amadori products, glycophore), protein oxidative damage (ischemia modified albumin) and nitrosative/nitrative stress (nitric oxide, peroxy-nitrite, S-nitrosothiols and nitro-tyrosine) in morbidly obese subjects as compared to lean controls, whereas plasma tryptophan and total thiols were statistically decreased. Bariatric surgery generally reduces the abnormalities in the glycoxidation of proteins and nitrosative/nitrative stress. Noteworthily, in the patients with metabolic syndrome (MS+), we showed no differences in most redox biomarkers, as compared to morbidly obese patients without MS (MS−). However, two markers: were able to differentiate MS+ and MS− with high specificity and sensitivity: peroxy-nitrite (>70%) and S-nitrosothiols (>60%). Further studies are required to confirm the diagnostic usefulness of such biomarkers.

Novel insights into ferroptosis: Implications for age-related diseases

Rapid increase in aging populations is an urgent problem because older adults are more likely to suffer from disabilities and age-related diseases (ARDs), burdening healthcare systems and society in general. ARDs are characterized by the progressive deterioration of tissues and organs over time, eventually leading to tissue and organ failure. To date, there are no effective interventions to prevent the progression of ARDs. Hence, there is an urgent need for new treatment strategies. Ferroptosis, an iron-dependent cell death, is linked to normal development and homeostasis. Accumulating evidence, however, has highlighted crucial roles for ferroptosis in ARDs, including neurodegenerative and cardiovascular diseases. In this review, we a) summarize initiation, regulatory mechanisms, and molecular signaling pathways involved in ferroptosis, b) discuss the direct and indirect involvement of the activation and/or inhibition of ferroptosis in the pathogenesis of some important diseases, and c) highlight therapeutic targets relevant for ARDs.

Oral and Topical Centella asiatica in Type 2 Diabetes Mellitus Patients with Dry Skin: A Three-Arm Prospective Randomized Double-Blind Controlled Trial

Introduction

Uncontrolled diabetes mellitus (DM) is related to skin disorders, particularly dry skin. Pathogenesis of dry skin in type 2 diabetes mellitus (T2DM) rises from the chronic hyperglycemia causing an increase in advanced glycation end-products (AGEs), proinflammatory cytokines, and oxidative stress. Combination of oral and topical Centella asiatica (CA) is expected to treat dry skin in T2DM patients more effectively through decreasing N(6)-carboxymethyl-lysine (CML) and interleukin-1α (IL-1α) and increasing superoxide dismutase (SOD) activity.

Methods

A three-arm prospective, double-blind, randomized, controlled study was performed to evaluate the efficacy of the oral and topical CA extract in 159 T2DM patients with dry skin. The subjects were divided into the CA oral (CAo) 2 × 1.100 mg + CA topical (CAt) 1% ointment group, oral placebo (Plo) + CAt group, and Plo and topical placebo (Plt) group. Dry skin assessment was performed on day 1, 15, and 29, while evaluation of CML, IL-1α, and SOD activity was on day 1 and 29.

Result

Effectivity of CAo + CAt combination was assessed based on HbA1c and random blood glucose (RBG). In well-controlled blood glucose, on day 29, the percentage of SRRC decrement was greater in the CAo + CAt group compared to the control group (p = 0.04). SCap value in the CAo + CAt group was greater than that in the control group (p = 0.01). In the partially controlled blood glucose, increment of SOD activity in the CAo + CAt group was greater than that in the control group (p = 0.01). There were medium-to-strong correlation between CML with SOD (r = 0.58, p < 0.05) and IL-1α with SOD (r = 0.70, p < 0.05) in well-controlled blood glucose. Systemic and topical adverse events were not significantly different between groups.

Conclusion

CAo and CAt combination can be used to significantly improve dry skin condition through increasing SOD activity in T2DM patients with controlled blood glucose.

Ex vivo antioxidant preconditioning improves the survival rate of bone marrow stem cells in the presence of wound fluid

The advancement of autologous mesenchymal stem cell (MSC) therapy for the treatment of non-healing diabetic wounds is hampered by endogenous MSC dysfunction and limited viability of cells post-transplantation into the pathological wound environment. The development of effective strategies to restore the functional capabilities of these impaired MSCs prior to transplantation may be a key to their ultimate success as wound repair mediators. The current study therefore investigated whether antioxidant preconditioning [7.5 mM N-acetylcysteine (NAC) + 0.6 mM ascorbic 2-phosphate (AAP)] could restore the growth rate, migration ability and viability of impaired MSCs and whether this restored state is maintained in the presence of diabetic wound fluid (DWF). Healthy control (source: wild type, C57BL/6J mice) (n = 12) and impaired/diabetic MSCs (source: obese prediabetic, B6.Cg-Lepob/J mice) (n = 12) were isolated from the bone marrow of mice. Treatment groups post-isolation were as follow: (a) No treatment (baseline phenotype): MSCs expanded in standard growth media (SGM) (±8 days) and only exposed to growth media. (b) DWF (baseline response): MSCs expanded in SGM (±8 days) followed by exposure to DWF (24 hours, 48 hours, 96 hours). (c) Antioxidant preconditioning (preconditioned phenotype): MSCs expanded in the presence of NAC/AAP (±8 days). (d) Antioxidant preconditioning + DWF (preconditioned response): MSCs expanded in the presence of NAC/AAP (±8 days) followed by exposure to DWF (24 hours, 48 hours, 96 hours). The results demonstrated that expansion of MSCs (both healthy control and impaired diabetic) in the presence of combined NAC/AAP treatment improved ex vivo MSC viability and protected MSCs in the presence of DWF. Despite improved viability, AAP/NAC could however not rescue the reduced proliferation and migration capacity of impaired diabetic MSCs. The protective effect of NAC/AAP preconditioning against the toxicity of DWF could however be a potential strategy to improve cell number post-transplantation.

Poor Glycaemic Control Is Associated with Increased Lipid Peroxidation and Glutathione Peroxidase Activity in Type 2 Diabetes Patients

Glycaemic control is the main focus of managing diabetes and its complications. Hyperglycaemia induces oxidative stress favouring cellular damage and subsequent diabetic complications. The present study was conducted to compare the plasma total antioxidant capacity (TAC) and individual antioxidant marker antioxidant status of type 2 diabetics (T2D) with good ((+) GC) and poor ((-) GC) glycaemic control with prediabetic (PDM) and normoglycaemic (NG) individuals. T2D (n = 147), PDM (n = 47), and NGC (n = 106) were recruited as subjects. T2D and PDM had lower plasma TAG than NG subjects. T2D and PDM had significantly higher GPx activity and plasma MDA concentrations than NG. PDM showed the highest SOD activity. T2D (-) GC showed significantly elevated GPx activity and higher MDA level and significantly lower SOD activity among all study groups. Lower plasma TAC and higher plasma MDA indicate the presence of oxidative stress in T2D and PDM. Elevated GPx activity in T2D, PDM, and particularly in T2D (-) GC suggests a compensatory response to counteract excess lipid peroxidation in the hyperglycaemic state. Decline in SOD activity advocates the presence of glycation and excess lipid peroxidation in T2D.

Higher oxidative balance score is associated with better glycemic control among Iranian adults with type-2 diabetes

The oxidative balance score (OBS) is a measure of combined pro- and anti-oxidant exposure status, with a higher OBS representing a predominance of anti- over pro-oxidant exposures. We aimed to examine the association of OBS and glycemic control among Iranian adults with type-2 diabetes. This cross-sectional study was conducted among 476 adults with type-2 diabetes (mean age 56.2 y; 66.6% female). Fasting glycosylated hemoglobin (HbA_1c) and serum glucose (FSG) levels were measured as markers of glycemic control. The OBS was calculated by combining information from a total of 18 a priori selected pro- and anti-oxidant components. These components were comprised of the following four categories: dietary anti-oxidants (i.e., dietary intakes of selenium, fiber, retinol, α-carotene, β-carotene, β-cryptoxanthin, lutein, lycopene, vitamin D, vitamin E, folate, and vitamin C); dietary pro-oxidants (i.e., dietary intakes of iron, saturated fatty acid, and poly-unsaturated fatty acid); non-dietary anti-oxidants (i.e., physical activity); and non-dietary pro-oxidants (i.e., smoking and obesity). After adjusting for several potential confounders in the analysis of covariance models, multivariable adjusted means of HbA_1c and FSG of subjects in the highest tertile of OBS were significantly lower than those in the lowest tertile (for HbA_1c: mean difference -0.73%; and for FSG: mean difference -10.2 mg/dL; both P < 0.050). The findings suggest that a higher OBS, indicating a predominance of anti- over pro-oxidant exposures, is associated with a better glycemic control among Iranian adults with type-2 diabetes. However, future prospective studies of adequate methodological quality are warranted to confirm these findings.

Association between Glycated Hemoglobin with the Levels of Serum Proinflammatory Cytokines and Antioxidants in Patients with Type 2 Diabetes Mellitus in Universitas Sumatera Utara Hospital

BACKGROUND:

Hyperglycemia condition in diabetes mellitus (DM) influences proinflammatory cytokine levels and disrupts antioxidant balances. Glycated Hemoglobin is used as a biomarker of glycemic control in DM.

AIM:

This study aimed to analyse the association between glycated Hemoglobin with the levels of serum proinflammatory cytokines (interleukin (IL)-6) and antioxidants (glutathione peroxidase (GPx) and glutathione (GSH)) in type 2 diabetes mellitus (T2DM) patients in Universitas Sumatera Utara (USU) Hospital.

METHODS:

A total of eighty-nine T2DM patients were recruited at USU Hospital. Glycated Hemoglobin levels were measured using routine laboratory tests at USU Hospital. The IL-6, GPx, and GSH levels were measured using enzyme-linked immunosorbent (ELISA) method. The statistical significance was determined using the Kruskal Wallis test, followed by Mann-Whitney test (p < 0.05).

RESULTS:

The mean of glycated hemoglobin (%), IL-6 (pg/ml), GPx (ng/ml), and GSH (ng/ml) levels in T2DM patients were 8.96 ± 2.28, 59.27 ± 16.04, 32.13 ± 12.10, and 7.42 ± 3.50, respectively. Regarding the glycated Hemoglobin levels, 28.09% of patients had controlled diabetes, 24.72% of patients had poorly controlled diabetes, and 47.19% of patients had uncontrolled diabetes. The IL-6 levels of the three study groups based on glycated Hemoglobin levels were related significantly (p < 0.05), but there was no statistically significant difference observed between the GPx and GSH levels (p > 0.05).

CONCLUSION:

The present study suggests that the glycated Hemoglobin was associated with the levels of serum IL-6 levels but not GPx and GSH levels in T2DM patients in USU Hospital.

Cross-sectional correlates of oxidative stress and inflammation with glucose intolerance in prediabetes

BACKGROUND

Prediabetes is a condition in which blood glucose level is above the normal but below the diagnostic value of diabetes mellitus. Besides progression to diabetes mellitus, prediabetic subjects are at risk for cardiovascular disease (CVD). It is associated with oxidative stress and inflammation and therefore this research was conducted with the aim to evaluate the risk of cardiovascular disease in prediabetic subjects by measuring the markers of oxidative stress and inflammation and their possible correlation with glucose intolerance.

MATERIALS AND METHODS

A total of 400 human subjects were recruited for the present cross-sectional study. Of them, 200 were prediabetic subjects and 200 were age and gender-matched control subjects. Blood samples were collected from all participants and analyzed for 8-hydroxy-2'-deoxy-guanosine (8-OHdG), malondialdehyde (MDA), reduced glutathione (GSH) and high sensitivity C-reactive protein (hs-CRP).

RESULTS

The markers of oxidative stress i.e. 8-OHdG and MDA were found to be significantly increased in prediabetic subjects as compared to control subjects except GSH, which was significantly reduced in prediabetic subjects. Similarly, hs-CRP (a marker of inflammation) was significantly increased in prediabetic subjects compared to controls. On correlation analysis, 8-OHdG, MDA and hs-CRP were significantly and positively correlated with glucose intolerance in prediabetes whereas GSH showed significant negative correlation with glucose intolerance.

CONCLUSION

In conclusion, markers of oxidative stress and inflammation should be taken into consideration while evaluating the risk for CVD in prediabetes since these markers were well correlated with glucose intolerance in prediabetic subjects.

The Antioxidant Activity of Pistachios Reduces Cardiac Tissue Injury of Acute Ischemia/Reperfusion (I/R) in Diabetic Streptozotocin (STZ)-Induced Hyperglycaemic Rats

Diabetes mellitus is an important risk factor for the development of heart pathology. Myocardial infarction is the cause of death occurring after prolonged ischemia of the coronary arteries. Restoration of blood flow is the first intervention against heart attack, although the process of restoring blood flow to the ischemic myocardium could cause additional injury. This phenomenon, termed myocardial ischemia-reperfusion (MI-R) injury, is characterized by the formation of oxygen radicals. Pistachios have significant glucose- and insulin-lowering effects and can improve the inflammatory contest by downregulating both the expression and the circulating levels of several metabolic risk markers. The monocyte/macrophage cell line J774 was used to assess the extent of protection by natural raw (NP) and roasted salted (RP) pistachios against lipopolysaccharide (LPS)-induced inflammation. Moreover, antioxidant activity of NP and RP was assessed in an in vivo model of paw edema in rats induced by carrageenan (CAR) injection in the paw. This study evaluates the antioxidant properties of pistachios on the inflammatory process associated with myocardial ischemia/reperfusion injury (I/R) in diabetic rats. Rats were pre-treated with either NP or RP pistachios (30 mg/kg) 18 h prior to the experimental procedure.

Results: Here, we demonstrated that treatment with NP reduced myocardial tissue injury, neutrophil infiltration, adhesion molecules (ICAM-1, P-selectin) expression, proinflammatory cytokines (TNF-α, IL-1β) production, nitrotyrosine and PAR formation, NF-κB expression and apoptosis (Bax, Bcl-2) activation. This data clearly showes modulation of the inflammatory process, associated with MI-R injury, following administration of pistachios.

Cadmium-Induced Oxidative Stress Impairs Glycemic Control in Adolescents

Experimental evidence suggests that cadmium (Cd) boosts oxidative stress that may result in toxicity on the endocrine system also in humans. The aim of this study was to investigate the glycemic control and oxidative stress markers in male adolescents with increased urinary levels of cadmium. We investigated 111 males, aged 12–14 years, living in a polluted area of Sicily and a control age-matched population (n = 60) living 28–45 km far from the polluted site. Malondialdehyde (MDA), total antioxidant activity (TAC), metallothionein-1A (MT-1A) gene expression, insulin resistance by the homeostatic model assessment (HOMA-IR), and urinary cadmium were investigated. Cd levels were significantly higher in adolescents living in the polluted area than in control age-matched subjects. Adolescents with elevated Cd levels had a significant increase in MDA, MT-1A, and HOMA-IR and reduced TAC compared to the control group. A robust correlation was found between urinary cadmium and MT-1A, HOMA-IR, and MDA whereas an inverse correlation was identified between urinary cadmium and TAC. This study indicates that cadmium burden alters glycemic control in adolescents and suggests that oxidative stress plays a key role in cadmium-induced insulin resistance, increasing the risk of developing metabolic disorders.

Antioxidative Categorization of Twenty Amino Acids Based on Experimental Evaluation

In view of the great importance bestowed on amino acids as antioxidants in oxidation resistance, we attempted two common redox titration methods in this report, including micro-potassium permanganate titration and iodometric titration, to measure the antioxidative capacity of 20 amino acids, which are the construction units of proteins in living organisms. Based on the relative intensities of the antioxidative capacity, we further conducted a quantitative comparison and found out that the product of experimental values obtained from the two methods was proven to be a better indicator for evaluating the relative antioxidative capacity of amino acids. The experimental results were largely in accordance with structural analysis made on amino acids. On the whole, the 20 amino acids concerned could be divided into two categories according to their antioxidative capacity. Seven amino acids, including tryptophan, methionine, histidine, lysine, cysteine, arginine and tyrosine, were greater in total antioxidative capacity compared with the other 13 amino acids.

Zanthoxylum heitzii Modulates Ferric Nitrilotriacetate-Dependent Oxidative Alterations in Four Vital Organs: An In Vitro Organoprotective Model

Ferric nitrilotriacetate (Fe-NTA) is a highly reactive compound used to induce degenerative disorders through oxidative stress (OS). Zanthoxylum heitzii (Z. heitzii) is a spice used as a medicinal plant to treat a variety of illnesses. This study investigated the ability of extracts from the leaves, fruits, roots, and barks of Z. Heitzii to inhibit Fe-NTA mediated oxidative damage in rats. The supernatant of rat liver homogenates was pretreated with the extracts for one hour before the induction of oxidative damage using a solution of Fe-NTA (400 mM). The activities of superoxide dismutase (SOD), catalase, and peroxidases were measured together with the marker of lipid peroxidation and the level of glutathione. The pretreated groups showed a significant increase in the activity of SOD, catalase, and peroxidases. The methanolic extract from the leaves of Z. heitzii (36.78 ± 3.30) and aqueous extract from the fruits (37.01 ± 2.52) showed the highest activities of SOD in the liver. The lowest concentration of MDA was found in the liver, and the glutathione was greater in the brain. Conclusively, these results suggest that Z. heitzii might be a chemoprotector which may be used in for prevention of distinct types of diseases induced by oxidative stress.