Diabetes mellitus and oxidative stress-A concise review

The effects of taurine supplementation on oxidative stress indices and inflammation biomarkers in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Reduced serum level of taurine in type 2 diabetes mellitus (T2DM) was shown to be associated with the metabolic alterations and clinical complications of diabetes. Dietary supplementation with taurine may attenuate oxidative stress and inflammatory responses in T2DM as well as alleviate diabetes-induced complications. Hence, this study evaluated the effect of taurine supplementation on oxidative stress and inflammatory biomarkers in patients with T2DM.

METHODS

Fifty patients with T2DM were randomly allocated to two groups to consume either taurine (containing 1000 mg taurine), or placebo (containing crystalline microcellulose) three times per day for 8 weeks. Anthropometric data, dietary intake, serum total antioxidant capacity (TAC), malondialdehyde (MDA), the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), serum levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were assessed before and after intervention.

RESULTS

There was a significant increase in SOD (5.1%, p = 0.004) and CAT (4.22%, p = 0.001) after 8 weeks of taurine supplementation. In addition, serum levels of MDA (26.33%, p = 0.001), hs-CRP (16.01%, p = 0.001), and TNF-α (11.65%, p = 0.03) significantly decreased in the taurine group compared with baseline. Following treatment, the taurine group had fewer serum levels of MDA (p = 0.04), hs-CRP (p = 0.002) and TNF-α (p = 0.006) than the placebo group. Also, a significant increase was observed in SOD (p = 0.007), and CAT (p = 0.001) in the taurine group compared with the placebo group. There were no differences in the serum levels of IL-6 or TAC.

CONCLUSIONS

The findings of this study showed that taurine supplementation improved some oxidative stress indices and inflammatory biomarkers in patients with T2DM.Trial registration The protocol of this clinical trial is registered with the Iranian Registry of Clinical Trials (http://www.IRCT.IR, identifier: IRCT20121028011288N16).

Effect on Adipose Tissue of Diabetic Mice Supplemented with n-3 Fatty Acids Extracted from Microalgae

BACKGROUND

Type 2 Diabetes Mellitus (T2DM) is considered a chronic noncommunicable disease in which oxidative stress is expected as a result of hyperglycaemia. One of the most recent approaches is the study of microalgae fatty acids and their possible antioxidant effect.

OBJECTIVE

This study aimed to analyse the effect of supplementation with n-3 fatty acids extracted from microalgae on the total antioxidant capacity (TAC) and lipid peroxidation of adipose tissue and plasma from diabetic (db/db) and healthy (CD1) mice.

METHODS

Mice were supplemented with lyophilized n-3 fatty acids extracted from microalgae or added to the diet, from week 8 to 16. TAC assay and Thiobarbituric Acid Reactive Substances assay (TBARS) were performed on adipose tissue and plasma samples.

RESULTS

The supplementation of lyophilized n-3 fatty acids from microalgae increased the total antioxidant capacity in adipose tissue of diabetic mice (615.67μM Trolox equivalents vs 405.02μM Trolox equivalents from control mice, p<0.01) and in the plasma of healthy mice (1132.97±85.75μM Trolox equivalents vs 930.64±32μM Trolox equivalents from modified diet mice, p<0.01). There was no significant effect on lipid peroxidation on both strains.

CONCLUSION

The use of n-3 fatty acids extracted from microalgae could be a useful strategy to improve total antioxidant capacity in T2DM.

Comparison of salivary nitric oxide and oral health in diabetic patients with and without xerostomia

BACKGROUND AND OBJECTIVE

Diabetes mellitus (DM) is a chronic multi-systemic metabolic disorder; diabetic patients are more prone to xerostomia and oral health problems than others. There are evidences that nitric oxide (NO) plays an important role in healthy salivary gland function, prevention of insulin resistance and progression of diabetes mellitus. The aim of this study was to compare the salivary NO level between type 2 diabetic (T2DM) patients with and without xerostomia.

METHODS

In this case control study, 70 patients with T2DM, which were matched according to age, sex, type of disease control, were enrolled conveniently. The subjects based on abeslang test were allocated to the two groups; 35 patients with xerostomia and 35 patients without xerostomia. Unstimulated whole saliva was collected by spitting method. NO levels was measured by ELISA method using Griess reaction. Data was analyzed using t-test, ANOVA and logistic regression analysis to examine the association of salivary NO and xerostomia.

RESULTS

The mean and standard deviation of salivary NO in the diabetic subjects with xerostomia was significantly lower than diabetic subjects without xerostomia (138 ± 94.58 μmol/L vs. 356.61 ± 302.81 μmol/L (P-value = 0.001). In logistic regression analysis, salivary NO level was associated with 0.994 fold decreased risk of xerostomia in diabetic subjects after adjustment for age, gender, FBS and HbA1c.

CONCLUSIONS

The present study indicates salivary nitric oxide level was a predictor of xerostomia in diabetic patients. More longitudinal studies are necessary to understand the association of salivary NO level with diabetes-induced xerostomia.

Thiols as markers of redox status in type 1 diabetes mellitus

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is associated with inflammation and the production of reactive oxygen species (ROS). Systemically, free thiols (R-SH) can be oxidized by ROS and circulating R-SH concentrations may directly reflect the systemic redox status. In this study the association between R-SH and clinical parameters of T1DM, including glycated haemoglobin A1c (HbA1c), was investigated. This is of particular interest since thiols are amendable to therapeutic intervention.

METHODS

As part of a prospective cohort study, data from 216 patients with a mean age of 45 (12) years, 57% male, diabetes duration 22 (16, 30) years and HbA1c of 60 (11) mmol/mol were examined. Baseline data were collected in 2002 and follow-up data in 2018. Cox proportional hazards regression analysis, with age, sex, HbA1c and R-SH, was used to assess prognostic factors for the development of complications.

RESULTS

At baseline, the plasma concentration of R-SH was 281.8 ± 34.0 μM. In addition to a lower concentration of NT-proBNP in the highest R-SH quartile (305-379 µM) there were no differences in baseline characteristics between the quartiles of R-SH. The Pearson correlation coefficient for R-SH and NT-proBNP was -0.290 (p < 0.001). No significant correlation between R-SH and baseline HbA1c (r = -0.024, p = 0.726) was present. During follow-up, 42 macrovascular and 92 microvascular complications occurred. In Cox regression, R-SH was not a prognostic factor for the development of microvascular [hazard ratio (HR) 0.999 (95% confidence interval (CI) 0.993, 1.005)] and macrovascular [HR 0.993 (95% CI 0.984, 1.002)] complications.

CONCLUSIONS

In addition to a negative association with NT-proBNP, no relevant relationships between R-SH and parameters of T1DM, including HbA1c, were present in this study.

In Vitro Antioxidant Activities of the Aqueous and Methanolic Stem Bark Extracts of Piliostigma thonningii (Schum.)

Oxidative stress has been recognized as a key driver of many ailments affecting humankind. Free radicals attack biologically important biomolecules, impairing their functioning, thereby initiating and exacerbating diseases. As a comeback, antioxidant therapies have been proposed as novel approaches to ameliorating oxidative stress-associated diseases including chronic ones. Antioxidants are thought to employ multifaceted and multitargeted mechanisms that either restore oxidative homeostasis or prevent free radical buildup in the body, which overwhelm the endogenous defenses. Plants have been used for many ages across time to manage human diseases, and have a host of antioxidant phytocompounds. Piliostigma thonningii is traditionally used for the management of inflammation, malaria fever, rheumatism, and insanity, among other diseases caused by a disturbed redox state in the body. In this study, in vitro antioxidant activities of the methanolic and aqueous stem bark extracts of P. thonningii were evaluated using the in vitro antilipid peroxidation, the 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical scavenging, and the ferric reducing antioxidant power assay methods. The obtained results revealed remarkable antioxidant activities of the studied plant extracts as evidenced by the low IC50 and EC50 values. These antioxidant activities could be due to the presence of antioxidant phytochemicals like flavonoids, carotenoids, tannins, and phenols, among others. Therefore, the therapeutic potency of this plant could be due to its antioxidant properties. This study recommends in vivo antioxidant efficacy testing of the studied plant extracts, as well as isolation and characterization of bioactive antioxidant compounds that are potent against oxidative stress.

Amino acid modified gadofullerene protects against insulin resistance induced by oxidative stress in 3T3-L1 adipocytes

GF-Ala afforded a significant protection against insulin resistance induced by oxidative stress in 3T3-L1 adipocytes. It could reverse the increase of JNK activation and decreases of insulin-stimulated PI3K, Akt, p70S6K activation and GLUT4 translocation.

Proatherogenic Importance of Carbamylation-induced Protein Damage and Type 2 Diabetes Mellitus: A Systematic Review

INTRODUCTION & BACKGROUND

Protein carbamylation is a non-enzymatic and irreversible posttranslational process. It affects functions of numerous enzymes, hormones and receptors playing several roles in diabetes pathogenesis by changing their native structures. Detrimental consequences of oxidative protein damage comprise, but are not limited to glyoxidation, lipoxidation and carbonylation reactions. Since the carbamylated plasma proteins are strongly related to the glycemic control parameters of diabetes, they may have an additive value and emerge as potential biomarkers for the follow up, prognosis and treatment of diabetes mellitus.

METHODS & RESULTS

To conduct our systematic review, we used PubMed and Semantic Scholar, and used 'Protein carbamylation and diabetes' and 'Protein carbamylation and atherosclerosis' as keywords and looked into about five hundred manuscripts. Manuscripts that are not in English were excluded as well as manuscripts that did not mention carbamylation to maintain the focus of the present article. Similar to glycation, carbamylation is able to alter functions of plasma proteins and their interactions with endothelial cells and has been shown to be involved in the development of atherosclerosis.

CONCLUSION

At this stage, it seems clear that protein carbamylation leads to worse clinical outcomes. To improve patient care, but maybe more importantly to improve healthcare-prevention, we believe the next stage involves understanding how exactly protein carbamylation leads to worse outcomes and when and in what group of people anti-carbamylation therapies must be employed.

Angiotensin II receptor Neprilysin inhibitor (LCZ696) compared to Valsartan attenuates Hepatotoxicity in STZ-induced hyperglycemic rats

Background and objectives: Although diabetic-induced hepatotoxicity is less common, it can be included in the list of target organ pathologies associated with diabetes. This study aimed to investigate the potential therapeutic role of sacubitril/valsartan (LCZ696) in modulating oxidative and inflammatory injuries and liver fibrosis in STZ-induced hyperglycemic rats in comparison to valsartan alone. Materials and Methods: Following the induction of diabetes using a single dose of streptozotocin (STZ), STZ-induced hyperglycemic animals were administered LCZ696 or valsartan for 6 weeks. Glucose, transaminases, lipid profile, tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin - 6 (IL-6), were estimated using the obtained serum. Oxidative stress biomarkers including thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were measured in the liver homogenate. Additionally, the levels of TNF-α, IL-1β, IL-6, and nuclear factor - kappa β (NF-κB) levels were estimated in hepatic tissue. To assess the general histopathological changes, harvested liver tissue was treated with hematoxylin and eosin or Masson's trichrome staining to detect fibrosis. Results: STZ-induced hyperglycemic rats demonstrated high blood glucose, dyslipidemia, and significant elevation in hepatic transaminases, proinflammatory cytokines, NF-κB, lipid peroxidation, and hepatic fibrosis, with impairment in antioxidant enzymes. In STZ-induced hyperglycemic rats, the administration of LCZ696 ameliorated hyperglycemia, dyslipidemia, improved liver functions, and boosted antioxidants enzymes. Furthermore, LCZ696 therapy attenuated oxidation, inflammation, progression of liver injury, and hepatic fibrosis. LCZ696 was superior to valsartan in reducing AST, hepatic fibrosis, tissue IL-1β, TNF-α and NF-κB. In addition, compared with the valsartan group, LCZ696 significantly increased the antioxidant parameters such as GSH, SOD, CAT and GPx. Conclusion: Collectively, our data demonstrated that LCZ696 could suppress the progression of diabetes-induced hepatic fibrosis, correlating with reduced oxidative stress, hepatic inflammation and NF-κB compared with valsartan alone.

Hypoglycemic Potential of Supplementation with a Vegetable and Legume Juice Formula in Type 2 Diabetic Patients

BACKGROUND AND OBJECTIVE

Type 2 diabetes affects a large number of people all over the world; hence, it is worthy to supplement those patients with a food formula containing biologically active ingredients that can help to control the disease and its complications. The present study was designed to prepare a plant formula in the form of a juice taken during treatment to synergies and reduce the drug dose used and minimize disease complications.

MATERIALS AND METHODS

The formula is formed of spinach, broccoli, celery, green beans and chickpea. The total fat, fatty acids, polyphenol content and the antioxidant power of the formula were determined. The blood sugar tolerance curves of the volunteers were followed after breakfast alone, breakfast and treatment dose, also when this formula was given before breakfast.

RESULTS

The vegetable and legume juice could reduce postprandial glucose level when given before the breakfast and the effect was more or less similar to the effect of the treatment drug. The juice proved to contain some polyphenols and possess an antioxidant character. Analysis proved that it is rich in polyunsaturated fatty acids.

CONCLUSION

It is recommended to use this juice for diabetic patients to reduce hyperglycemia and synergize the effect of the used drug. It can thus avoid health problems that occur to those patients when using drugs for long time and in massive amounts.

Plasma concentrations of vitamin A and E and risk of dysglycemia in first-trimester pregnant Saudi women

BACKGROUND

Existing evidence suggest that low concentrations of vitamin A and E may have a contribution to the development of diabetes complications; however, data regarding the status of vitamin A and E among individuals with prediabetes are lacking. This study aimed to examine the association of plasma concentrations of vitamin A and E with the glycemic control status among first trimester pregnant Saudi women.

METHODS

In this cross-sectional study, 1102 first trimester pregnant Saudi women were recruited from antenatal clinics. Sociodemographic and anthropometric information were collected, and laboratory analyses of blood glycated hemoglobin (A1C) and plasma vitamins A and E were performed. Subjects were classified as normoglycemic, prediabetic, or undiagnosed diabetic. Multinomial regression models adjusted for age estimated the adjusted odds ratios (aORs) and [95% confidence intervals (CIs)].

RESULTS

Among the sample, 78.8% (n = 868) had normal glycemic control, while 19.1% (n = 211) had prediabetes and 2.1% (n = 23) had undiagnosed diabetes. Plasma concentrations of vitamin A and E of prediabetic participants were at a level midway between that of normoglycemic and diabetic participants (p < 0.01). Compared to subjects with normoglycemic status, those with higher concentrations of vitamin A and E had lower odds of being prediabetic (aOR = 0.27 [0.21-0.35] and aOR = 0.95 [0.94-0.96], respectively) or diabetic (aOR = 0.18 [0.13-0.24] and aOR = 0.93 [0.92-0.94], respectively).

CONCLUSIONS

Our findings indicate a possible contribution of vitamins A and E to the progression of prediabetes to diabetes. Future longitudinal studies are needed to elucidate the association between the antioxidant status and dysglycemia. Clinicians should monitor the glycemic and the antioxidant status closely and provide dietary guidance where needed.

Association of Urinary Polycyclic Aromatic Hydrocarbons and Diabetes in Korean Adults: Data from the Korean National Environmental Health Survey Cycle 2 (2012-2014)

PURPOSE

To investigate the associations between the urinary levels of polycyclic aromatic hydrocarbons (PAHs) and diabetes mellitus in Korean adults.

MATERIALS AND METHODS

We examined the data of 6478 participants aged ≥19 years from the Korean National Environmental Health Survey (KoNEHS) cycle 2 (2012-2014). The urinary levels of 1-hydroxypyrene (1-OHP), 2-naphthol (2-NAP), 1-hydroxyphenathrene (1-OHPhe), and 2-hydroxyfluorene (2-OHFlu) were measured by gas chromatography-mass spectrometry. Diabetes mellitus was defined as a self-report of physician-diagnosed diabetes mellitus or the use of oral hypoglycemics or insulin. Analyses were adjusted for sex, age, body mass index, household income, alcohol consumption, physical activity, urinary creatinine and cotinine, menopausal status, and quartiles of all other PAHs.

RESULTS

The prevalence of diabetes was 6.5% in the study population. In men, the geometric means of the 2-NAP and 2-OHFlu levels were higher in participants with diabetes mellitus than in those without diabetes mellitus [4.11 vs 3.26 μg/L (P <0.05) and 0.45 vs 0.40 μg/L (P <0.05), respectively]. In women, the geometric mean of 2-NAP levels was also higher in participants with diabetes mellitus than in those without diabetes mellitus (1.81 vs 0.56 μg/L, P <0.05), but there were no significant differences in geometric means for other PAHs. A higher odds ratio (OR) of diabetes was found in participants with the highest quartiles of urinary 2-NAP [OR 1.83, 95% confidence interval (CI) 1.29-2.60] and 2-OHFlu (OR 1.81, 95% CI 1.10-2.98) than in those with the lowest quartiles.

CONCLUSION

The urinary 2-NAP and 2-OHFlu levels were associated with diabetes mellitus in Korean adults. Further studies are needed to determine a potential causal relationship between PAH exposure and diabetes mellitus and its underlying mechanism.

Interrelationship between oxidative stress, DNA damage and cancer risk in diabetes (Type 2) in Riyadh, KSA

Type 2 Diabetes Mellitus (T2DM) is the most widely known type of disorder of the endocrine system marked by hyperglycemia resulting either due to deficiency of insulin and or resistance. Persistent hyperglycemia induces oxidative stress and is suggested to play a prominent role in the pathophysiology underlying T2DM. Besides, oxidative stress can result in DNA damage leading to high cancer risk. Current study aimed to evaluate status of oxidative damage, damage to DNA and cancer biomarkers in regard to increased glucose in T2DM patients and to correlate the glycemic state with cancer. A total of 150 subjects consisting of control (50) and T2DM patients (1 0 0) were enrolled. Additionally, three tertiles were created among the two groups based on levels of HbA1c (Tertile I = 5.37 ± 0.34, n = 50; Tertile II = 6.74 ± 0.20, n = 50; Tertile III = 9.21 ± 1.47, n = 50). Oxidative stress parameters including malondialedehyde (MDA) and antioxidant enzymes were measured. Damage to DNA was analyzed by measuring the levels of DNA damage adduct-8 hydroxy deoxy Guanosine (8-OHdG). To detect cancer resulting from oxidative stress, cancer biomarkers CEA, AFP, CA125, CA-15, CA19-9, prolactin were measured in these subjects. All measurements were analysed by SPSS software. Levels of MDA and antioxidant enzymes altered significantly in T2DM group at p < 0.001 and p < 0.05 level of significance. Significant DNA damage accompanied with elevated levels of CEA, CA19-9 and decreased CA125, AFP and prolactin were noted in T2DM group. CA 19-9 and CEA levels increased at p < 0.05, whereas levels of prolactin decreased significantly (p < 0.001) in T2DM group compared to control. Additionally the mean values of DNA damage adduct 8-OHdG differ significantly at P < 0.01 between the two groups. However, no significant correlation in oxidative stress parameter, antioxidant enzymes, DNA damage and neither with the highest tertile of HbA1c (>7.5%) was noted. Based on the results obtained in the present study, we conclude that there is considerable change in oxidative stress and DNA damage in T2DM patients. Hence, assumption that the oxidative stress could cause cancer in T2DM as a result of hyperglycemic state was not speculated in this study.

Hormones and oxidative stress: an overview

In aerobes, oxygen is essential for maintenance of life. However, incomplete reduction of oxygen leads to generation of reactive oxygen species. These oxidants oxidise biological macromolecules present in their vicinity and thereby impair cellular functions causing oxidative stress (OS). Aerobes have evolved both enzymatic and nonenzymatic antioxidant defences to protect themselves from OS. Although hormones as means of biological coordination involve in regulation of physiological activities of tissues by regulating metabolism, any change in their normal titre leads to pathophysiological states. While, hormones such as melatonin, insulin, oestrogen, progesterone display antioxidant features, thyroid hormone, corticosteroids and catecholamines elicit free radical generation and OS, and the role of testosterone in inducing OS is debateable. This review is an attempt to understand the impact of free radical generation and cross talk between the hormones modulating antioxidant defence system under various pathophysiological conditions.

Bavachin Protects Human Aortic Smooth Muscle Cells Against β-Glycerophosphate-Mediated Vascular Calcification and Apoptosis via Activation of mTOR-Dependent Autophagy and Suppression of β-Catenin Signaling

Vascular calcification is a major complication of cardiovascular disease and chronic renal failure. Autophagy help to maintain a stable internal and external environment that is important for modulating arteriosclerosis, but its pathogenic mechanism is far from clear. Here, we aimed to identify the bioactive compounds from traditional Chinese medicines (TCM) that exhibit an anti-arteriosclerosis effect. In β-glycerophosphate (β-GP)-stimulated human aortic smooth muscle cells (HASMCs), the calcium level was increased and the expression of the calcification-related proteins OPG, OPN, Runx2, and BMP2 were all up-regulated, followed by autophagy induction and apoptosis. Meanwhile, we further revealed that β-GP induced apoptosis of human osteoblasts and promoted differentiation of osteoblasts through Wnt/β-catenin signaling. Bavachin, a natural compound from Psoralea corylifolia, dose-dependently reduced the level of intracellular calcium and the expression of calcification-related proteins OPG, OPN, Runx2 and BMP2, thus inhibiting cell apoptosis. In addition, bavachin increased LC3-II and beclin1 expression, along with intracellular LC3-II puncta formation, which autophagy induction is Atg7-dependent and is regulated by suppression of mTOR signaling. Furthermore, addition of autophagy inhibitor, wortmannin (WM) attenuated the inhibitory effect of bavachin on β-GP-induced calcification and apoptosis in HASMCs. Collectively, the present study revealed that bavachin protects HASMCs against apoptosis and calcification by activation of the Atg7/mTOR-autophagy pathway and suppression of the β-catenin signaling, our findings provide a potential clinical application for bavachin in the therapy of cardiovascular disease.

Bioactive proteins and phytochemicals from legumes: Mechanisms of action preventing obesity and type-2 diabetes

The Fabaceae family of plants include a variety of seeds with multiple shapes, sizes, and colors; with a great diversity of bioactive compounds found in legume seeds. Legumes are an excellent source of protein, peptides and phytochemicals which are present in significant amounts. These bioactive compounds have been reported to reduce the risk of developing non-communicable diseases (NCD), such as obesity and type-2 diabetes. In this narrative review, we discuss the biological potential of bioactive compounds found in legumes and the health benefits associated with their consumption as an alternative approach in the management of NCD. Current extraction methods, characteristics of the bioactive compounds, and different in vitro and in vivo studies evaluating the bioactivity of legume bioactives are reviewed and discussed.

Targeting microRNAs as a Therapeutic Strategy to Reduce Oxidative Stress in Diabetes

Diabetes mellitus is a group of heterogeneous metabolic disorders characterized by chronic hyperglycaemia as a consequence of pancreatic β cell loss and/or dysfunction, also caused by oxidative stress. The molecular mechanisms involved inβ cell dysfunction and in response to oxidative stress are also regulated by microRNAs (miRNAs). miRNAs are a class of negative gene regulators, which modulate pathologic mechanisms occurring in diabetes and its complications. Although several pharmacological therapies specifically targeting miRNAs have already been developed and brought to the clinic, most previous miRNA-based drug delivery methods were unable to target a specific miRNA in a single cell type or tissue, leading to important off-target effects. In order to overcome these issues, aptamers and nanoparticles have been described as non-cytotoxic vehicles for miRNA-based drug delivery. These approaches could represent an innovative way to specifically target and modulate miRNAs involved in oxidative stress in diabetes and its complications. Therefore, the aims of this review are: (i) to report the role of miRNAs involved in oxidative stress in diabetes as promising therapeutic targets; (ii) to shed light onto the new delivery strategies developed to modulate the expression of miRNAs in diseases.

Possible antioxidant mechanism of coenzyme Q10 in diabetes: impact on Sirt1/Nrf2 signaling pathways

Oxidative stress is a major complication in diabetes mellitus. The aim of this study was to investigate potential antioxidant activity of coenzyme Q10 (Co Q10) against hyperglycemia-induced oxidative stress in diabetic rat and unraveling its mechanism of action by focusing on silent information regulator 1 (Sirt1) and nuclear factor E2-related factor 2 (Nrf2) mRNA expression level. Furthermore, the activity of two Nrf2-dependent antioxidant enzymes (superoxide dismutase and catalase) in the liver of diabetic rats was studied. After induction of diabetes in rats using streptozotocin (55 mg/kg), rats were divided into five groups of six each. Groups 1 and 2 (healthy control groups) were injected with isotonic saline or sesame oil; group 3 received Co Q10 (10 mg /Kg /day), group 4, as a diabetic control, received sesame oil; and group 5 was diabetic rats treated with Co Q10. Afterwards, serum and liver samples were collected, and oxidative stress markers, lipid profile, as well as the expression of Sirt1 and Nrf2 genes were measured. Diabetes induction significantly reduced expression level of Sirt1 and Nrf2 mRNAs and also declined catalase, superoxide dismutase activities, and total thiol groups levels in diabetic group in comparison to healthy controls, while a significant increase was found in the levels of malondialdehyde and lipid profile. Co Q10 treatment significantly up-regulated Sirt1 and Nrf2 mRNA levels along with an increase in catalase activity in diabetic group as compared with untreated diabetic rats. Furthermore, Co Q10 caused a marked decrease in malondialdehyde levels and significantly improved lipid profile. Our data demonstrated that Co Q10 may exert its antioxidant activity in diabetes through the induction of Sirt1/Nrf2 gene expression.

Toxic effects of subchronic oral acetamiprid exposure in rats

Acetamiprid, a selective agonist of type-2 nicotinic acetylcholine receptors, is one of the most widely used neonicotinoids. The hepato- and nephrotoxic potential of acetamiprid has not been clarified although it is known to be toxic to other several organ systems, including the nervous, respiratory and immune systems. The present study aimed to investigate acetamiprid liver and kidney toxicity in male rats after a 90-day subchronic exposure to 12.5, 25 and 35 mg/kg. The biochemical and oxidative damage parameters were determined in the plasma and tissue samples as well as histopathological evaluation in the liver and kidney tissues. Acetamiprid caused oxidative damage and affected the liver, denoted by injury markers including the levels of cholesterol, and alanine aminotransferase and aspartate aminotransferase enzymes. There was also a decrease in plasma urea, uric acid and creatinine levels, all of which might result from liver injury. Additionally, acetamiprid was more toxic to the liver than the kidney according to the histopathological examinations. In conclusion, acetamiprid exhibited hepatotoxic potential at all treatment doses on male Sprague Dawley rats.

Protective role of Moringa oleifera leaf extract on cardiac antioxidant status and lipid peroxidation in streptozotocin induced diabetic rats

Moringa oleifera is a medicinal plant with great therapeutic potential. The leaves of Moringa oleifera are used by Indians in herbal medicines to treat diabetes. The present study is aimed to determine the protective role of Moringa oleifera in cardiac tissues under diabetic conditions. Diabetic rats were treated orally with methanolic extract of Moringa oleifera leaves at a dose of 300 mg/Kg body weight for 60 days. The effect of extract on serum glucose, glycated hemoglobin, plasma insulin and the levels of thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP), conjugated dienes (D), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-reductase (GRD) and reduced glutathione content (GSH) were estiated. Metformin and atorvastatin were used as standard drugs. A significant increase in plasma insulin, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-reductase (GRD) and reduced glutathione content (GSH) and a significant decrease in serum glucose, glycated hemoglobin, thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP) and conjugated dienes (CD) were observed in the treated groups. This study evaluated the antioxidant potential of methanolic extract of Moringa oleifera leaves. These findings suggest the protective role of Moringa oleifera against oxidative stress in the heart of diabetic rats.

Chokeberry juice supplementation in type 2 diabetic patients - impact on health status

Recent literature evidence indicates the potential use of chokeberry preparations in the prevention and treatment of some chronic noncommunicable diseases. The aim of the present study was to evaluate the effects of the three months oral chokeberry juice supplementation in type 2 diabetic patients, as well as its influence on hematological parameters and certain parameters of the renal dysfunction. The study was designed as an open-label trial, which included 35 patients who have received the herbal supplement, polyphenol-rich chokeberry juice (150 ml/day, three times a day for 50 ml), in addition to their standard therapy. Chokeberry juice as a rich source of polyphenol compounds could be an effective preventive and therapeutic agent in diabetes mellitus type 2. Hematological and biochemical parameters were measured at baseline, after 3 months with the chokeberry juice supplementation and after the next 3 months without the chokeberry juice supplementation (follow-up period). Significant difference was noticed in the levels of LDL-cholesterol, glycated hemoglobin and serum creatinine (p < 0.05), as well as in the levels of some hematological parameters, such as white blood cell and lymphocyte count (p < 0.01), hematocrit, blood hemoglobin, mean corpuscular volume, hemoglobin and hemoglobin concentration and red blood cell count (p < 0.05). The daily consumption of the chokeberry juice could improve the health status in patients with type 2 diabetes mellitus, in combination with their standard therapy.

Antioxidant effect of endothelin-1 receptor antagonist protects the rat kidney against chronic injury induced by hypertension and hyperglycemia

ABSTRACT Hypertension and Diabetes mellitus are the two main causes of chronic kidney disease that culminate in the final stage of kidney disease. Since these two risk factors are common and can overlap, new approaches to prevent or treat them are needed. Macitentan (MAC) is a new non-selective antagonist of the endothelin-1 (ET-1) receptor. This study aimed to evaluate the effect of chronic blockade of ET-1 receptor with MAC on the alteration of renal function observed in hypertensive and hyperglycemic animals. Genetically hypertensive rats were divided into control hypertensive (HT-CTL) group, hypertensive and hyperglycemic (HT+DIAB) group, and hypertensive and hyperglycemic group that received 25 mg/kg macitentan (HT-DIAB+MAC25) via gavage for 60 days. Kidney function and parameters associated with oxidative and nitrosative stress were evaluated. Immunohistochemistry for neutrophil gelatinase-associated lipocalin (NGAL), ET-1, and catalase in the renal cortex was performed. The HT+DIAB group showed a decrease in kidney function and an increase in NGAL expression in the renal cortex, as well as an increase in oxidative stress. MAC treatment was associated with attenuated ET-1 and NGAL production and increases in antioxidant defense (catalase expression) and nitric oxide production. In addition, MAC prevented an increase in oxidant injury (as measured by urinary hydroperoxide and lipid peroxidation), thus improving renal function. Our results suggest that the antioxidant effect of the ET-1 receptor antagonist MAC is involved in the improvement of kidney function observed in hypertensive and hyperglycemic rats.

Evaluation of a labdane diterpene forskolin isolated from Solena amplexicaulis (Lam.) Gandhi (Cucurbitaceae) revealed promising antidiabetic and antihyperlipidemic pharmacological properties

Solena amplexicaulis (Lam.) Gandhi (Family Cucurbitaceae) is one of the important plant species used by the Irula tribes of Walayar valley of southern Western Ghats, India for the management of diabetes. To confirm the antidiabetic property of S. amplexicaulis, the present study was addressed using crude methanolic leaf extract of S. amplexicaulis (MeOHSa) and its isolated compound, Forskolin against streptozotocin (STZ) induced diabetic rats. The oral glucose tolerance test (OGTT), blood glucose, lipid profile, serum liver markers, antioxidants, hemoglobin and glycogen were evaluated using standard procedure. The oral administration of Forskolin and MeOHSa (600 mg/kg b.w.) for 30 days resulted in significant restoration of all these parameters supported by histopathological observations too. The results clearly suggest that the Forskolin (diterpene) possess potent antidiabetic and antihyperlipidemic activities, which may be considered as a lead molecule for therapeutic purposes, and the source of Forskolin i.e. S. amplexicaulis can be further exploited for pharmaceutical industries.

Inhalation exposure to cigarette smoke induces endothelial nitric oxide synthase uncoupling and enhances vascular collagen deposition in streptozotocin-induced diabetic rats

Smoking is an acknowledged risk factor for vascular disorders, and vascular complication is a main outcome of diabetes. Hence, we investigated the impact of cigarette smoke on blood vessels in diabetes, postulating that smoking might aggravate diabetic vascular impairment. Sprague-Dawley rats were divided into four groups: control, cigarette smoke-exposed, diabetic, and cigarette smoke-exposed diabetic groups. Streptozotocin-induced diabetic rats were exposed to cigarette smoke by inhalation at total particulate matter concentration of 200 μg/L for 4 h/day, 5 day/week for a total of 4 weeks. Diabetes caused structural change of aorta, but additional cigarette smoke exposure did not induce further alteration. Collagen, a marker for fibrosis, was increased in media of diabetic aorta, and this increase was augmented by cigarette smoke. Cigarette smoke induced endothelial nitric oxide synthase (eNOS) uncoupling in the diabetic group. Malondialdehyde was increased and glutathione was decreased in blood from diabetes, but these effects were not exaggerated by cigarette smoke. Cigarette smoke caused NADPH oxidase (NOX) 2 expression in diabetic aorta and enhanced diabetes-induced NOX4 expression in aorta. Taken together, cigarette smoke exposure can aggravate vascular fibrosis and induce eNOS uncoupling in diabetes under experimental condition, suggesting that smoking might exacerbate diabetic vascular impairments.

Impact of Rutin and Vitamin C combination on oxidative stress and glycemic control in patients with type 2 diabetes

AIM

This study aimed to investigate the effect of Vitamin C alone and in combination with Rutin on the glycemic control, insulin resistance, lipid profile and oxidative stress markers in patients with type 2 diabetes.

METHODS

A prospective, randomized, controlled study conducted on 53 type 2 diabetes patients randomized into 3 groups; (group A) 20 received Rutin with vitamin C, (group B) 20receivedvitamin C and (group C)13 received antidiabetic treatment only. Fasting Blood Glucose (FBG), Hemoglobin A1c (HbA1c), fasting insulin, Malondialdehyde, Superoxide dismutase, Lipid profile and patients' quality of life (QOL) using SF-36 questionnaire were assessed in all patients at baseline and after 8 weeks.

RESULTS

At baseline, the 3 groups were comparable while FBG was lower in group C versus group A and B (p = 0.0021). After 8 weeks, a significant reduction was observed in % change of FBG in groups A and B versus group C (p = 0.0165, 0.0388 respectively). Low Density Lipoprotien-cholesterol (LDL-c) and Total cholesterol (TC) levels significantly improved in group B versus baseline (p = 0.0239,0.0166 respectively). QOL, physical functioning and energy domains improved significantly in group A versus group C (p = 0.0049, 0.0253 respectively), while role limitation to physical health and to emotional problem improved significantly in group B versus group C (p = 0.0267,0.0280 respectively).

CONCLUSION

Vitamin C supplementation alone or with Rutin significantly reduced the % change of FBG compared to controls but had no effect on HbA1c, FBG,TC, fasting insulin and HOMA-IR or oxidative stress in T2DMpatients.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03437902.

Lentinus edodes Exposure before and after Fetus Implantation: Materno-Fetal Development in Rats with Gestational Diabetes Mellitus

Background: The presence of β-glucans and phenolic compounds in Lentinus edodes suggests this mushroom can be used as a nutritional supplement. Two gestational conditions (before and after fetus implantation) were evaluated, and Lentinus edodes exposure was performed in diabetes mellitus rat model induced by streptozotocin in pre-clinical tests. Methods: On the 20th day of pregnancy, cesarean sections were performed. Blood was collected for biochemical, hematologic parameters and oxidative stress biomarkers. Placenta and amniotic fluid were collected, and fetuses were analyzed through morphological evaluation. Results: The mushroom did not reduce the severe hyperglycemia of the mother-concept but promoted an increase in maternal insulin levels; reduced the levels of alanine aminotransferase, and aspartate aminotransferase, triglyceride and total cholesterol; protected the animals from post-implantation losses. Liver damage induced by streptozotocin was reversed in experimental groups. Conclusions: Lentinus edodes mushroom has antioxidant properties that can minimize the damage caused by gestational diabetes mellitus.

The Effect of the Chronic Administration of DPP4-Inhibitors on Systemic Oxidative Stress in Rats with Diabetes Type 2

Type 2 diabetes (T2DM) is characterized by well-preserved insulin secretion; however, the surrounding tissue is insensitive to insulin, resulting in increased blood glucose level due to the inability of tissues to convert glucose into energy. As a result of chronic non-regulation of glucose levels and high daily fluctuations in the blood, the micro- and macrovascular complications occur in these patients. Complications develop through two main mechanisms: induction of oxidative stress and innate immunity. In this regard, the aim of this study was to examine the effect of four week administration of DPP4 inhibitors (saxagliptin, sitagliptin and vildagliptin) to the parameters of oxidative stress and antioxidant defense in the group of rats with diabetes type 2 (T2DM). Sixty Wistar albino rats were divided randomly into 5 groups: group I: control healthy group; group II: rats with diabetes type 2; group III: rats with diabetes type 2 treated with 0.6 mg/kg of sitagliptin; group IV: rats with diabetes type 2 treated with 0.45 mg/kg of saxagliptin, group V: rats with diabetes type 2 treated with 9 mg/kg vildagliptin. The rats from experimental groups were fed with a high-fat diet for 4 weeks and after 6–8 h of starvation received one dose of streptozotocin (STZ) intraperitoneally (25 mg/kg body weight) to induce T2DM. Animals with fasting glucose above 7 mmol / L and insulin over 6 mmol / L were included in the study as rats with T2DM. Upon completion of the experiments, the blood was collected from the anesthetized animals and used for sphectrophotometrical determination of parameters of oxidative stress, and antioxidative defense. T2DM induced significant increase in production of reacitve oxygen species (ROS) (superoxide anion radical and hydrogen peroxide), but additional four-week administration of gliptins induced decrease in ROS values. On the other hand, T2DM induced decrease of nitric oxide, superoxide dismutase, catalaze, and reduced gluthation and concomitant therapy with gliptins induced increase of these parametars, suggesting significant antioxidant potential of this group of drugs.

Synthesis, Structural Studies, and α-Glucosidase Inhibitory, Antidiabetic, and Antioxidant Activities of 2,3-Dihydroquinazolin-4(1H)-ones Derived from Pyrazol-4-carbaldehyde and Anilines

A series of new quinazoline derivatives were designed and synthesized via a one-pot condensation reaction between isatoic anhydride and aromatic aldehydes with anilines using aluminum sulfate as a catalyst in refluxing ethanol. Their structures were confirmed by their physical, IR, 1H NMR, 13C NMR, and mass spectroscopy data and evaluated for some biological effects, including the antioxidant and α-glucosidase inhibitory activities as well as some in vivo hematological parameters. The ability of synthesized compounds in the inhibition of α-glucosidase was also investigated through the in silico study. The significant and important changes in some hematological tests were perceived. Notably, compound 4h showed more reducing effects on cholesterol and triglyceride levels. This molecule certainly has the potential to be developed as the antihyperlipemic compound. The tested compounds, in particular, compounds 4j and 4l, were found to be uniquely reducing blood sugar levels. The entire synthesized compounds showed the potent α-glucosidase inhibitory activity compared with acarbose as a standard material. Amongst, the compounds 4h and 4i showed the strongest enzyme inhibitory potentials than the standard drug acarbose. There was a good correlation between in vitro and in silico studies for ligands 4i and 4l. The majority of compounds presented a good radical scavenging activity, though the compound 4j exhibited the strongest activity, even to the standard of ascorbic acid. Further studies are required to determine whether these main compounds could be a potential treatment for diabetes and hyperlipidemia diseases.

Midlife women's health consequences associated with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common female endocrinopathies. Its symptoms may appear as early as adolescence and may include irregular menstrual periods, amenorrhea, hirsutism and obesity. Regardless of their phenotypic appearance, women with PCOS are metabolically obese. PCOS is associated with metabolic syndrome, type 2 diabetes, depression, cardiovascular disease and gynecological cancers. The metabolic disorders in obese women with PCOS are invariably due to insulin resistance, while inflammation, oxidative stress and possible interaction with environmental factors are among the features linking women with PCOS alone to metabolic disorders. The current review aims to highlight the relationship between PCOS and midlife women's health complications.

High performance liquid chromatographic profiling of antioxidant and antidiabetic flavonoids purified from Azadirachta indica (neem) leaf ethanolic extract

Azadirachta indica (neem) is a tropical and semi-tropical tree native to the whole Indian subcontinent. Neem leaves are rich in flavonoids, which exhibit important pharmacological activities targeting almost all human organs. In order to produce a purified extract of neem leaves enriched of antioxidant and antidiabetic flavonoids, the ethanolic extract of neem leaves has been further undergone to liquid-liquid extractions by using three different organic solvents, i.e. dichloromethane, n-butanol and ethyl acetate. Qualitative and quantitative analyses were performed on the extracts obtained by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Astragalin, quercitrin, isoquercitrin, nicotiflorin and rutin were the only flavonoids found among those screened. By comparing all HPLC chromatograms of purified extracts as obtained with different solvents, it was found that the qualitative-quantitative composition of flavonoids depends upon the extraction solvent used; in particular, dichloromethane allows extraction of 89.5 % quercitrin, 5.3 % isoquercitrin, 5.2 % rutin; n-butanol allows extraction of 6.0 % isoquercitrin, 6.2 % nicotiflorin, 87.8 % rutin; ethyl acetate allows extraction of 4.2 % astragalin, 12.0 % quercitrin, 50.3 % isoquercitrin, 6.7 % nicotiflorin, 26.9 % rutin. Thus, depending on the specific purposes and needs, each of these three extraction solvents has the potential to prepare formulations enriched with the most suitable flavonoids composition.

Therapeutic effect of resveratrol supplementation on oxidative stress: a systematic review and meta-analysis of randomised controlled trials

Background

Resveratrol is a naturally occurring polyphenol compound mainly found in grapes and red wine. The evidence has suggested that resveratrol has an antioxidant effect. However, the results are inconsistent and inconclusive. Thus, we conducted a systematic review and meta-analysis to evaluate the effect of resveratrol supplementation on markers of oxidative stress.

Methods

We searched PubMed, ISI Web of Science, EMBASE, Scopus and the Cochrane library up to December 2018 to identify randomised controlled trials (RCTs) assessing resveratrol supplementation effects on oxidative markers. Heterogeneity, publication bias, risk of bias and subgroup analysis were analysed. This meta-analysis was conducted in accordance with the guidelines of the Preferred ReportingItems for Systematic Reviews and Meta-Analysis (PRISMA).

Results

Meta-analysis of data from 12 RCTs did not support significant effect of resveratrol supplementation on circulating levels of superoxide dismutase (SOD) (standardized mean difference (SMD) (1.12), (95% CI −0.91 to 3.1), p=0.28), catalase (CAT) (SMD (−0.07), (95% CI −1.4 to 1.3), p=0.92) and glutathione peroxidase (GPx) (SMD (−0.76), (95% CI −2.56 to 1.04), p=0.40). Although, resveratrol supplementation increased significantly circulating total antioxidant capacity (TAC) concentrations (SMD (0.52), (95% CI −0.02 to 1.07), p=0.05). Severe heterogeneity was observed between studies, and no obvious publication bias was observed in included RCTs.

Conclusion

Collectively, our findings of available RCTs did no show any benefit of resveratrol supplementation on SOD, CAT and GPx except for TAC. Well-designed RCTs are necessary to confirm these results.

STAT3 and Nrf2 pathways modulate the protective effect of verapamil on lung injury of diabetic rats

OBJECTIVE

We aimed to assess the protective role of verapamil, L-type calcium channel blockers, against early lung damage in diabetic rats. Lung injury has recently been recognized as a consequent complication of diabetes mellitus. Hyperglycemia induces inflammatory changes in lung tissue early in the disease.

METHODS

Twenty four adult male rats were grouped into control, diabetic, diabetic treated with verapamil, and verapamil control. Streptozotocin (STZ) was used to induce diabetes. Oxidative parameters and antioxidative mechanisms were assessed in lung homogenate. Tumor necrosis factor alpha (TNFα) protein was measured as a pro-inflammatory mediator. Signal transducer and activator of transcription 3 (STAT3) gene expression and nuclear erythroid factor 2 (Nrf2) immunoexpression were screened.

RESULTS

The lung showed oxidative damage and inflammatory infiltration in STZ diabetic rats early at 2 weeks. The parameters significantly improved in lung tissue treated with verapamil. Histopathology of the lung tissue confirmed the results. Inhibition of STAT3/TNFα pathway was involved in the protection offered by verapamil. Activation of Nrf2 together with an increasing antioxidant capacity of diabetic lung significantly ameliorates the injury induced by diabetes.

CONCLUSIONS

Verapamil afforded protection in diabetic lung injury. The protection was mediated by the anti-inflammatory and antioxidant effects of verapamil.

Oxidation Stress-Mediated MAPK Signaling Pathway Activation Induces Neuronal Loss in the CA1 and CA3 Regions of the Hippocampus of Mice Following Chronic Cold Exposure

Chronic stress can damage homeostasis and induce various primary diseases. Although chronic cold stress is becoming an increasing problem for people who must work or live in extreme environments, risk-induced diseases in the central nervous system remain unstudied. Male C57BL/6 mice were exposed to an environment of 4 °C, 3 h per day for 1, 2, and 3 weeks and homeostasis in the hippocampus and neuronal apoptosis were evaluated by Western blotting, immunohistochemistry, TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, and immunofluorescence. The phenomena of oxidation stress, MAPK signaling pathway activation, anti-oxidation protein release, neuronal apoptosis increases, and neuronal proliferation inhibition were demonstrated in the CA1 and CA3 regions of mouse hippocampal tissues following cold exposure. We speculated that these phenomena were mediated by the MAPK pathway and were closely linked with oxidative stress in the hippocampus. This study provides novel concepts regarding neurodegenerative diseases, suggesting that chronic cold stress may be a critical factor to induce neurodegenerative diseases.

Acute Effects of Passion Fruit Juice Supplementation on Cardiac Autonomic Function and Blood Glucose in Healthy Subjects

Ascorbic acid supplementation provides beneficial effects on enhancing cardiac autonomic function in patients with heart failure. Ascorbic acid also reduces blood sugar levels and enhances insulin activity, and encourages cardiac autonomic function. Passion fruit is rich in ascorbic acid and potential antioxidants. This study aimed to evaluate the acute effects of passion fruit juice (PFJ) supplementation primarily on cardiac autonomic function and secondary on blood glucose in healthy subjects. A randomized cross-over trial was conducted in 14 healthy subjects aged 21.29±0.73 years. Subjects were supplemented with either 50% PFJ, or glucose and fructose solution as a placebo (PLA) at 3.5 mL/kg body mass with a 1-week washout between treatments in a single-dose design. Short-term heart rate variability and blood glucose levels were evaluated prior to supplementation (T0) and following supplementation for 30, 60, 90, and 120 min (T30, T60, T90, and T120, respectively). Indexes of cardiac autonomic function at T30, including high frequency power (P=0.03) and total power (P=0.01), were significantly higher and the ratio of low frequency/high frequency power was significantly lower (P=0.01) in the PFJ group compared to the PLA group. Blood glucose levels significantly increased at T30 in both PLA (P=0.00) and PFJ (P=0.00) groups. However, there were no significant differences between groups. A single administration of PFJ enhanced cardiac autonomic function through augmentation of parasympathetic activity, although it did not attenuate postprandial hyperglycemia. PFJ may be potentially recognized as beverage able to prevent cardiovascular disease.

Changes in sperm quality and testicular structure in a rat model of type 1 diabetes

Background

Chronic hyperglycemia is a characteristic of diabetes mellitus (DM). Long-lasting hyperglycemia can generate oxidative stress and reactive oxygen species. The effect of this condition on sperm quality and spermatogenesis leads to male infertility and reproductive dysfunction.

Objectives

To investigate changes in sperm quality, morphology of testicular structure, and stage of development of seminiferous tubules in a streptozotocin (STZ)-induced rat model of type 1 DM.

Methods

We divided 15 male Sprague Dawley rats into 2 groups. DM was induced in 7 rats using STZ (60 mg/kg intraperitoneally), while the other 8 were treated with citrate buffer as a vehicle control group. Rat semen was collected for quality measurements including motility, normal morphology, and concentration. Morphological changes in testicular structure and stage of development of seminiferous tubules were investigated by histology with hematoxylin and eosin (HE) staining.

Results

Significant decreases in all parameters of sperm quality and testicular weight were found in rats with induced DM. Moreover, abnormal morphology of seminiferous tubules including separation of the germinal epithelium, vacuolization, luminal sloughing of germ cells, and tubular atrophy was increased significantly in these rats, while the proportion of their seminiferous tubules at an early stage of development was significantly higher, but was dramatically decreased in the late stage of development when compared with that in vehicle-treated control rats.

Conclusions

DM has adverse effects on sperm quality, testicular structure, and development of seminiferous tubules. These findings may reflect the male infertility and reproductive dysfunction seen in patients with type 1 DM.

Alpha-Glucosidase and Alpha-Amylase Inhibitory Activities of Novel Abietane Diterpenes from Salvia africana-lutea

The re-investigation of a methanolic extract of Salvia africana-lutea collected from the Cape Floristic Region, South Africa (SA), afforded four new abietane diterpenes, namely 19-acetoxy-12-methoxycarnosic acid (1), 3β-acetoxy-7α-methoxyrosmanol (2), 19-acetoxy-7α-methoxyrosmanol (3), 19-acetoxy-12-methoxy carnosol (4), and two known named clinopodiolides A (5), and B (6), in addition to four known triterpenes, oleanolic, and ursolic acids (7, 8), 11,12-dehydroursolic acid lactone (9) and β-amyrin (10). The chemical structural elucidation of the isolated compounds was determined on the basis of one and two dimensional nuclear magnetic resonance (1D and 2D NMR), high-resolution mass spectrometry (HRMS), ultra violet (UV), fourier transform infrared (IR), in comparison with literature data. The in vitro bio-evaluation against alpha-glucosidase showed strong inhibitory activities of 8, 10, and 7, with the half inhibitory concentration (IC₅₀) values of 11.3 ± 1.0, 17.1 ± 1.0 and 22.9 ± 2.0 µg/mL, respectively, while 7 demonstrated the strongest in vitro alpha-amylase inhibitory activity among the tested compounds with IC₅₀ of 12.5 ± 0.7 µg/mL. Additionally, some of the compounds showed significant antioxidant capacities. In conclusion, the methanolic extract of S. africana-lutea is a rich source of terpenoids, especially abietane diterpenes, with strong antioxidant and anti-diabetic activities that can be helpful to modulate the redox status of the body and could therefore be an excellent candidate for the prevention of the development of diabetes, a disease where oxidase stress plays an important role.

Plant Extracts and Reactive Oxygen Species as Two Counteracting Agents with Anti- and Pro-Obesity Properties

Obesity is a complex disease of great public health significance worldwide: It entails several complications including diabetes mellitus type 2, cardiovascular dysfunction and hypertension, and its prevalence is increasing around the world. The pathogenesis of obesity is closely related to reactive oxygen species. The role of reactive oxygen species as regulatory factors in mitochondrial activity in obese subjects, molecules taking part in inflammation processes linked to excessive size and number of adipocytes, and as agents governing the energy balance in hypothalamus neurons has been examined. Phytotherapy is the traditional form of treating health problems using plant-derived medications. Some plant extracts are known to act as anti-obesity agents and have been screened in in vitro models based on the inhibition of lipid accumulation in 3T3-L1 cells and activity of pancreatic lipase methods and in in vivo high-fat diet-induced obesity rat/mouse models and human models. Plant products may be a good natural alternative for weight management and a source of numerous biologically-active chemicals, including antioxidant polyphenols that can counteract the oxidative stress associated with obesity. This review presents polyphenols as natural complementary therapy, and a good nutritional strategy, for treating obesity without serious side effects.

Comparative effects of glibenclamide, metformin and insulin on fetal pancreatic histology and maternal blood glucose in pregnant streptozotocin-induced diabetic rats

BACKGROUND

Oral hypoglycemic agents use during pregnancy was assumed to cause fetal macrosomia and skeletal deformities, and maternal complications due to significant transfer across placenta or ineffective control of blood glucose.

OBJECTIVE

This study investigated effects of insulin, metformin and glibenclamide on maternal blood glucose; and fetal crown-rump length, gross malformation and pancreatic histology in pregnant streptozotocin-induced diabetic rats.

METHODS

Twenty-five pregnant rats of groups 1 to 5 as normal and diabetic controls; and diabetic treated with insulin, metformin and glibenclamide were used. Experimental GDM was induced using 45 and 35mg/Kgbw of intraperitoneal streptozotocin.

RESULTS

Metformin, Insulin and Glibenclamide significantly reduced maternal glucose by 140.6mg/dL, 103.2mg/dL and 98.54mg/dl; respectively and showed islets with regular interlobular ducts, islets with some irregular interlobular ducts, and islets with many irregular interlobular ducts in histological fetal pancreatic photomicrographs respectively. This depicts metformin having highest ameliorative effect. There were no significant differences in maternal and fetal body weights, maternal blood glucose between diabetic groups, and fetal gross examination.

CONCLUSION

At the doses used in this research, metformin and glibenclamide showed no adverse effects on maternal and fetal features in the treatment of GDM. Thus, they can be used as safe and inexpensive alternatives to insulin.

The anti-diabetic and antioxidant effects of a combination of Commiphora mukul, Commiphora myrrha and Terminalia chebula in diabetic rats

OBJECTIVE

Effects of Commiphora mukul and Commiphora myrrha ethanolic extracts and Terminalia chebula hydro-ethanolic extract combination were evaluated in streptozotocin (STZ)-induced diabetic rats.

MATERIALS AND METHODS

Male Wistar rats (n=48) were randomly assigned into: control; diabetic; diabetic+metformin (300 mg/kg); diabetic+dose 1 of herbal combination (438 mg/kg of C. mukul+214 mg/kg of C. myrrha+857 mg/kg of T. chebula); diabetic+dose 2 (642 mg/kg of C. mukul+214 mg/kg of C. myrrha+642 mg/kg of T. chebula); and diabetic+dose 3 (857 mg/kg of C. mukul+438 mg/kg of C. myrrha+1714 mg/kg t of T. chebula). All treatments were given orally by gavage. Diabetes was induced by STZ (60 mg/kg, i.p.). At the end of study (day 28), blood glucose, insulin and lipid profile; as well as hepatic malondialdehyde (MDA) and thiol content, and superoxide dismutase (SOD) and catalase (CAT) activities were determined.

RESULTS

In diabetic rats, plasma glucose, triglycerides (TG), total cholesterol (TC), and LDL-C, as well as hepatic MDA levels were elevated but plasma HDL-C and insulin, and hepatic thiol content and SOD and CAT activities were reduced compared to control (p<0.01-p<0.001). In diabetic+dose 3, plasma TC, TG, and LDL-C and hepatic MDA level decreased (p<0.001), while plasma HDL-C and insulin, and hepatic thiol content, and SOD and CAT activities increased compared to diabetic (p<0.01-p<0.001). Treatment with dose 1 and 2 improved such abnormalities in diabetic rats except for insulin level (p<0.05-p<0.001). The herbal combination effects were comparable to those of metformin. Metformin did not significantly change serum insulin and HDL-C levels, and hepatic SOD activity; however, serum levels of TC, TG, and LDL-C, as well as hepatic MDA levels, thiol content and CAT activity were improved compared to diabetic (p<0.05-p<0.001).

CONCLUSION

These results indicate that this herbal combination acts as an anti-diabetic, antioxidant and hypolipidemic agent and it may be suggested as a beneficial remedy for diabetic patients.

Conserved roles of glucose in suppressing reactive oxygen species-induced cell death and animal survival

Carbohydrate overconsumption increases blood glucose levels, which contributes to the development of various diseases including obesity and diabetes. It is generally believed that high glucose metabolism increases cellular reactive oxygen species (ROS) levels, damages insulin-secreting cells and leads to age-associated diabetic phenotypes. Here we find that in contrast, high glucose suppresses ROS production induced by paraquat in both mammalian cells and the round worm C. elegans. The role of glucose in suppressing ROS is further supported by glucose's ability to alleviate paraquat's toxicity on C. elegans development. Consistently, we find that the ROS-regulated transcription factor SKN-1 is inactivated by glucose. As a result, the ROS/SKN-1-dependent lifespan extension observed in paraquat-treated animals, mitochondrial respiration mutant isp-1 and germline-less mutant glp-1 are all suppressed by glucose. Our study reveals an unprecedented interaction of glucose with ROS, which could have significant impact on our current understanding of glucose- and ROS-related diseases.

Insights on the Use of α-Lipoic Acid for Therapeutic Purposes

α-lipoic acid (ALA, thioctic acid) is an organosulfur component produced from plants, animals, and humans. It has various properties, among them great antioxidant potential and is widely used as a racemic drug for diabetic polyneuropathy-associated pain and paresthesia. Naturally, ALA is located in mitochondria, where it is used as a cofactor for pyruvate dehydrogenase (PDH) and α-ketoglutarate dehydrogenase complexes. Despite its various potentials, ALA therapeutic efficacy is relatively low due to its pharmacokinetic profile. Data suggests that ALA has a short half-life and bioavailability (about 30%) triggered by its hepatic degradation, reduced solubility as well as instability in the stomach. However, the use of various innovative formulations has greatly improved ALA bioavailability. The R enantiomer of ALA shows better pharmacokinetic parameters, including increased bioavailability as compared to its S enantiomer. Indeed, the use of amphiphilic matrices has capability to improve ALA bioavailability and intestinal absorption. Also, ALA's liquid formulations are associated with greater plasma concentration and bioavailability as compared to its solidified dosage form. Thus, improved formulations can increase both ALA absorption and bioavailability, leading to a raise in therapeutic efficacy. Interestingly, ALA bioavailability will be dependent on age, while no difference has been found for gender. The present review aims to provide an updated on studies from preclinical to clinical trials assessing ALA's usages in diabetic patients with neuropathy, obesity, central nervous system-related diseases and abnormalities in pregnancy.

Zinc, copper, and oxysterol levels in patients with type 1 and type 2 diabetes mellitus

BACKGROUND

The present study has the objective to assess the zinc (Zn), copper (Cu), and oxysterols plasma levels in type 1 (DM1) (n = 26) and type 2 (DM2) (n = 80) diabetes patients, as compared to healthy controls (n = 71), in order to testify whether metal levels may have a significant impact on the association between oxysterols and diabetes.

METHODS

Plasma trace elements and plasma oxysterols were assessed using atomic absorption spectrometry and LC-MS/MS, respectively. Lifestyle, smoking status, alcohol intake, and drug usage, as well as microvascular complications, were also monitored and reported.

RESULTS

The obtained data demonstrated that both DM1 and DM2 patients were characterized by significantly elevated HbA1c, FBG, TC, LDL-C, VLDL-C, and TG levels as compared to controls. Plasma Zn levels and Zn/Cu ratio in DM1 and DM2 patients were about 3- and 2-fold lower than controls. No significant differences in plasma Cu levels were reported. The 7-ketocholesterol (7-kchol) levels in DM1 and DM2 patients exceeded these values in healthy individuals by 2.5 and 5-fold, respectively. Similarly, cholestan-3β, 5α, 6β-triol (chol-triol) levels were more than 3- and 6-fold higher when compared to the respective values in non-diabetic controls. In regression models decreased plasma Zn and elevated oxysterol levels were significantly associated with HbA1c and fasting plasma glucose levels, after adjustment for anthropometric and clinical variables, as well as routine biochemical markers.

CONCLUSIONS

Plasma Zn concentration is inversely associated with both 7-kchol and chol-triol levels. Assessment of Zn and oxysterol levels may be used both for risk assessment and as targets for the treatment of diabetes mellitus.