Regulation of cardiac oxidative stress and lipid peroxidation in streptozotocin-induced diabetic rats treated with aqueous extract of Pimpinella tirupatiensis tuberous root

Lung molecular and histological changes in type 2 diabetic rats and its improvement by high-intensity interval training

BACKGROUND

Type 2 diabetes (T2D) leads to serious respiratory problems. This study investigated the effectiveness of high-intensity interval training (HIIT) on T2D-induced lung injuries at histopathological and molecular levels.

METHODS

Forty-eight male Wistar rats were randomly allocated into control (CTL), Diabetes (Db), exercise (Ex), and Diabetes + exercise (Db + Ex) groups. T2D was induced by a high-fat diet plus (35 mg/kg) of streptozotocin (STZ) administration. Rats in Ex and Db + Ex performed HIIT for eight weeks. Tumor necrosis factor-alpha (TNFα), Interleukin 10 (IL-10), BAX, Bcl2, Lecithin, Sphingomyelin (SPM) and Surfactant protein D (SPD) levels were measured in the bronchoalveolar lavage fluid (BALF) and malondialdehyde (MDA) and total antioxidant capacity (TAC) levels were measured in lung tissue. Lung histopathological alterations were assessed by using H&E and trichrome mason staining.

RESULTS

Diabetes was significantly associated with imbalance in pro/anti-inflammatory, pro/anti-apoptosis and redox systems, and reduced the SPD, lecithin sphingomyelin and alveolar number. Performing HIIT by diabetic animals increased Bcl2 (P < 0.05) and IL10 (P < 0.01) levels as well as surfactants components and TAC (P < 0.05) but decreased fasting blood glucose (P < 0.001), TNFα (P < 0.05), BAX (P < 0.05) and BAX/Bcl2 (P < 0.001) levels as well as MDA (P < 0.01) and MDA/TAC (P < 0.01) compared to the diabetic group. Furthermore, lung injury and fibrosis scores were increased by T2D and recovered in presence of HIIT.

CONCLUSION

These findings suggested that the attenuating effect of HIIT on diabetic lung injury mediated by reducing blood sugar, inflammation, oxidative stress, and apoptosis as well as improving pulmonary surfactants components.

Justicia carnea extracts ameliorated hepatocellular damage in streptozotocin-induced type 1 diabetic male rats via decrease in oxidative stress, inflammation and increasing other risk markers

IntroductionDiabetes mellitus is still a raging disease not fully subdued globally, especially in Africa. Our study aims to evaluate the anti-diabetic potentials of Justicia carnea extracts [crude (JCC), free (JFP) and bound phenol (JBP) fractions], in streptozotocin (STZ)-induced type-1 diabetes in male albino rats.Materials and MethodsAbout thirty (30) animals were induced for type 1 diabetes with STZ; thereafter, treatment began for 14 days, after which the animals were euthanized, blood/serum was collected, the liver was removed and divided into two portions, for biochemical and histopathological analyses. Standard procedures were used to evaluate the liver biomarkers, like alanine transaminase (ALT), fructose-1,6-bisphosphatase, glucose-6- phosphatase, hexokinase activities, albumin, bilirubin, hepatic glucose concentrations; antioxidant status and pro- and anti-inflammatory cytokines were similarly assessed.ResultsThese results revealed that the extracts ameliorated the harmful effects of STZ-induced diabetes in the liver by enhancing the activities of liver-based biomarkers, reducing the concentrations of pro-inflammatory cytokines and increasing the anti-inflammatory cytokine.DiscussionThe results agreed with previous research, and the free phenol fraction showed excellent results compared to othersConclusionThese suggested that J. carnea could serve as an alternative remedy in ameliorating liver complications linked to oxidative damage and inflammation in STZ-induced type-1 diabetes.

Vulgarin, a Sesquiterpene Lactone from Artemisia judaica, Improves the Antidiabetic Effectiveness of Glibenclamide in Streptozotocin-Induced Diabetic Rats via Modulation of PEPCK and G6Pase Genes Expression

The current investigation assessed the effect of the eudesmanolid, Vulgarin (VGN), obtained from Artemisia judaica (A. judaica), on the antidiabetic potential of glibenclamide (GLB) using streptozotocin (STZ) to induce diabetes. Seven groups of rats were used in the study; the first group received the vehicle and served as normal control. The diabetic rats of the second to the fifth groups were treated with the vehicle (negative control), GLB at 5 mg/kg (positive control), VGN at 10 mg/kg (VGN-10) and VGN at 20 mg/kg (VGN-20), respectively. The diabetic rats of the sixth and seventh groups were administered combinations of GLB plus VGN-10 and GLB plus VGN-20, respectively. The diabetic rats treated with GLB plus VGN-20 combination showed marked improvement in the fasting blood glucose (FBG), insulin and glycated hemoglobin (HbA1c), as well as the lipid profile, compared with those treated with GLB alone. Further, the pancreatic tissues of the diabetic rats that received the GLB+VGN-20 combination showed superior improvements in lipid peroxidation and antioxidant parameters than those of GLB monotherapy. The insulin content of the β-cells was restored in all treatments, while the levels of glucagon and somatostatin of the α- and δ-endocrine cells were reduced in the pancreatic islets. In addition, the concurrent administration of GLB+VGN-20 was the most effective in restoring PEPCK and G6Pase mRNA expression in the liver. In conclusion, the results demonstrated that the GLB+VGN-20 combination led to greater glycemic improvement in diabetic rats compared with GLB monotherapy through its antioxidant effect and capability to modulate PEPCK and G6Pase gene expression in their livers.

Hibiscus sabdariffa L. polyphenolic-rich extract promotes muscle glucose uptake and inhibits intestinal glucose absorption with concomitant amelioration of Fe2+ -induced hepatic oxidative injury

In this current study, the antidiabetic effectiveness of Hibiscus sabdariffa and its protective function against Fe²⁺ -induced oxidative hepatic injury were elucidated using in vitro, in silico, and ex vivo studies. The oxidative damage was induced in hepatic tissue by incubation with 0.1 mMolar ferrous sulfate (FeSO4) and then treated with different concentrations of crude extracts (ethyl acetate, ethanol, and aqueous) of H. sabdariffa flowers for 30 min at 37°C. When compared to ethyl acetate and aqueous extracts, the ethanolic extract displayed the most potent scavenging activity in ferric-reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and nitric oxide (NO) assays, with IC₅₀ values of 2.8 μl/ml, 3.3 μl/ml, and 9.2 μl/ml, respectively. The extracts significantly suppressed α-glucosidase and α-amylase activities (p < .05), with the ethanolic extract demonstrating the highest activity. H. sabdariffa significantly (p < .05) raised reduced glutathione (GSH) levels while simultaneously decreasing malondihaldehyde (MDA) and NO levels and increasing superoxide dismutase (SOD) and catalase activity in Fe²⁺ induced oxidative hepatic injury. The extract of the plant inhibited intestinal glucose absorption and increased muscular glucose uptake. The extract revealed the presence of several phenolic compounds when submitted to gas chromatography-mass Spectroscopy (GC-MS) screening, which was docked with α-glucosidase and α- amylase. The molecular docking displayed the compound 4-(3,5-Di-tert-butyl-4-hydroxyphenyl)butyl acrylate strongly interacted with α-glucosidase and α-amylase and had the lowest free binding energy compared to other compounds and acarbose. These results suggest that H. sabdariffa has promising antioxidant and antidiabetic activity. PRACTICAL APPLICATIONS: In recent years, there has been increased concern about the side effects of synthetic anti-diabetic drugs, as well as their expensive cost, especially in impoverished nations. This has instigated a radical shift towards the use of traditional plants, which are rich in phytochemicals many years ago. Among these plants, H. sabdariffa has been used to treat diabetes in traditional medicine. In this present study, H. sabdariffa extracts demonstrated the ability to inhibit carbohydrate digesting enzymes, facilitate muscle glucose uptake and attenuate oxidative stress in oxidative hepatic injury. Hence, demonstrating H. sabdariffa's potential to protect against oxidative damage and the complications associated with diabetes. Consumption of Hibiscus tea or juice may be a potential source for developing an anti-diabetic drug.

Intermittent fasting and exercise therapy abates STZ-induced diabetotoxicity in rats through modulation of adipocytokines hormone, oxidative glucose metabolic, and glycolytic pathway

Diabetes is a global, costly, and growing public health issue. Intermittent fasting (IF) and exercise therapy have been shown to improve insulin sensitivity (IS) in large studies, although the underlying processes are still unknown. The goal of this study, which included both nondiabetic and diabetic rats, was to look at the mechanisms of intermittent fasting and exercise in the management of diabetotoxicity. The effects of starvation and honey on the oral glucose tolerance test, insulin tolerance test, adipocytokines, oxidative glucose metabolic enzymes, glycolytic enzymes, food intake, and body weight in rats with streptozotocin‐induced diabetes were also investigated. In the nondiabetic phase, rats were administered an oral regimen of distilled water (0.5 ml/rat), honey (1 g/kg body weight), and interventions with IF, and starvation for 4 weeks while in the diabetic phase, after STZ or citrate buffer injections, interventions with IF, exercise, starvation, and honey treatment began for 4 weeks. At all OGTT and ITT points, there was a substantial rise in glucose in the STZ group. Adipocytokines hormone, oxidative glucose metabolic enzymes, glycolytic enzymes, and body weight were all affected by STZ when compared to starvation and honey, however, IF and exercise significantly reduced these alterations. In diabetic rats, intermittent fasting and exercise enhanced serum adipocytokines levels. These findings imply that adipokines modulate glycolytic/nonmitochondrial enzymes and glucose metabolic/mitochondrial dehydrogenase to mediate the antidiabetic effects of intermittent fasting and exercise.

Intermittent fasting and exercise therapy abates STZ‐induced diabetotoxicity in rats through modulation of adipocytokines hormone, oxidative glucose metabolic, and glycolytic pathway.

Combined effect of metformin and gallic acid on inflammation, antioxidant status, endoplasmic reticulum (ER) stress and glucose metabolism in fructose-fed streptozotocin-induced diabetic rats

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Metformin, gallic acid and a combination of both improved glucose metabolism and antioxidant status in diabetic rats.

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Metformin, gallic acid and a combination of both lowered levels of IL-6 and TNF-α in liver and pancreas of diabetic rats.

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Metformin, gallic acid and a combination of both decreased the expression of ATF4 in liver and pancreas of diabetic rats.

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Metformin/GA combination appeared more effective than metformin only and gallic acid only.

Over time, diabetes patients usually need combination therapy involving two or more agents, including phytonutrients to attain therapeutic targets. The purpose of this research is to elucidate the combined effect of metformin and gallic acid (GA) on glucose metabolism, inflammation as well as oxidative and endoplasmic reticulum (ER) stresses in fructose-fed diabetic rats. Thirty-five rats of Wistar strain were arbitrarily distributed into five groups, each containing seven animals as follows: normal control, diabetic control, groups administered 100 mg/kg bw metformin only, 50 mg/kg bw gallic acid only and a combination of both. Experimental animals were made diabetic by single injection of 40 mg/kg streptozotocin (intraperitoneally) subsequent to 14 days administration of 10 % fructose prior. Treatment of rats continued for 21 days following diabetes confirmation. Glucose and insulin levels as well as lipid profile were evaluated in the serum, while activities of catalase and superoxide dismutase were estimated in both liver and pancreas. In addition, levels of malondialdehyde, interleukin-6 and tumor necrosis factor-alpha, as well as expression of activating transcription factor-4 were evaluated in liver and pancreas of diabetic rats. Activities of glucose-6-phosphatase and glucokinase were also determined in liver of diabetic animals. Metformin only, GA only and combination of metformin and GA significantly improved antioxidant status and glucose homeostasis while inflammation and endoplasmic reticulum stress were significantly ameliorated in diabetic rats. Metformin/GA combination appeared to improve glucose metabolism by increasing insulin level and ameliorating the dysregulated activities of glucose metabolizing enzymes and ER stress better than either metformin only or GA only. It could be concluded that coadministration of metformin/GA produced a combined effect in ameliorating diabetes in Wistar rats and could be considered in treatment of diabetes.

Ekakitie L, Kappo AP. Effect of Solanum macrocarpon Linn leaf aqueous extract on the brain of an alloxan-induced rat model of diabetes

Objective

This study was designed to evaluate the protective effect of aqueous extract of Solanum macrocarpon Linn leaf in the brain of an alloxan-induced rat model of diabetes.

Methods

The experimental model of diabetes was induced by a single intraperitoneal injection of freshly prepared alloxan. Rats were then divided into six groups: normal control, diabetes control, diabetes group treated with metformin, and three diabetes groups treated with different concentrations of S. macrocarpon. Rats were sacrificed on day 14 of the experiment and different brain biochemical parameters were assessed and compared between groups.

Results

Administration of different doses of S. macrocarpon leaf aqueous extract was associated with significantly reduced levels of fasting blood glucose, lipid peroxidation, neurotransmitters, cholinesterases, cyclooxygenase-2 and nitric oxide compared with diabetes control rats. In addition, antioxidant enzyme activities were significantly increased in diabetes rats administered 12.45, 24.9 and 49.8 mg/kg body weight of S. macrocarpon versus diabetes control rats.

Conclusion

Aqueous extract of S. macrocarpon Linn leaf may be useful in the management of diabetic neuropathy.

Contributions from Mexican Flora for the Treatment of Diabetes Mellitus: Molecules of Psacalium decompositum (A. Gray) H. Rob & Brettell

Diabetes mellitus (DM) is cited as a serious worldwide health problem that occupies second place in causes of annual mortality in Mexico. Among Mexican flora, nearly 300 plant species have been employed as hypoglycemic in popular use. Thus, their study entertains great relevance In this context, this work contributes a clear and timely review of the plant species utilized in Traditional Mexican Medicine and experimental biological models in which not only have the hypoglycemic properties of the extracts and the isolated compounds been considered, but also the anti-inflammatory and antioxidant properties, taking into account an integral focus based on the complex mechanisms involved in the pathogenesis and physiopathology of DM. Among the species reviewed, we highlight Psacalium decompositum (Asteraceae), due to the potent hypoglycemic, anti-inflammatory, and antioxidant activity of the sesquiterpenes identified as majority compounds isolated from the root, such as cacalol and cacalone that also possess the capacity of increasing insulin levels. In this manner, the present manuscript attempts to contribute necessary information for the future study of bioactive molecules that are useful in the treatment of DM, as well as also being a contribution to the knowledge and diffusion of Mexican Traditional Medicine.

Medicinal Plants and Bioactive Compounds for Diabetes Management: Important Advances in Drug Discovery

BACKGROUND

Diabetes is a major public health problem in the world. It affects each and every part of the human body and also leads to organ failure. Hence, great progress is made in the field of herbal medicine and diabetic research.

OBJECTIVES

Our review will focus on the effect of bioactive compounds of medicinal plants which are used to treat diabetes in India and other countries.

METHODS

Information regarding diabetes, oxidative stress, medicinal plants and bioactive compounds was collected from different search engines like Science direct, Springer, Wiley online library, Taylor and francis, Bentham Science, Pubmed and Google scholar. Data was analyzed and summarized in the review.

RESULTS

Anti-diabetic drugs that are in use have many side effects on vital organs like heart, liver, kidney and brain. There is an urgent need for alternative medicine to treat diabetes and their disorders. In India and other countries, herbal medicine was used to treat diabetes. Many herbal plants have antidiabetic effects. The plants like ginger, phyllanthus, gymnea, aswagandha, aloe, hibiscus and curcuma showed significant anti-hyperglycemic activities in experimental models and humans. The bioactive compounds like Allicin, azadirachtin, cajanin, curcumin, querceitin, gingerol possess anti-diabetic, antioxidant and other pharmacological properties. This review focuses on the role of bioactive compounds of medicinal plants in the prevention and management of diabetes.

CONCLUSION

Moreover, our review suggests that bioactive compounds have the therapeutic potential against diabetes. However, further in vitro and in vivo studies are needed to validate these findings.

Swietenine potentiates the antihyperglycemic and antioxidant activity of Metformin in Streptozotocin induced diabetic rats

Diabetes mellitus or type-2 diabetes, commonly referred as diabetes, is a metabolic disorder that results in high blood sugar level. Despite the availability of several antidiabetic drugs in the market, they still do not adequately regulate blood sugar levels. Thus, in general people prefer to use herbal supplements/medicines along with antidiabetic drugs to control blood sugar levels. One of such herbal medicine is Swietenia macrophylla seeds. It is widely used in Asia for controlling blood sugar levels. One of the major bioactive compounds, Swietenine, is reported to be responsible for controlling blood glucose levels. However, there were no studies on its efficacy in controlling the blood glucose in diabetic rats. In this study, we evaluated the antihyperglycemic activity of Swietenine and its pharmacodynamic interaction with Metformin in Streptozotocin induced diabetes in rats. The activity of Swietenine was investigated at three different doses: 10, 20 and 40 mg/kg body weight (bw). Metformin (50 mg/kg bw) was used as a standard drug. Swietenine (20 and 40 mg/kg bw) and Metformin (50 mg/kg bw) showed significant effect in reducing the glucose, cholesterol, triglycerides, low-density lipoprotein, urea, creatinine, alanine transaminase, alkaline phosphatase, aspartate transaminase, alanine transaminase, and malondialdehyde level in serum while it had increased the high-density lipoprotein, glutathione, and total antioxidant capacity level. In addition, Swietenine (20 and 40 mg/kg) had shown significant synergistic effect with Metformin. Administration of Swietenine at 10 mg/kg bw neither showed activity nor influenced Metformin's activity. The results from this study confirmed the beneficial effects of Swietenine and its synergistic action with Metformin in controlling the dysregulated serum parameters in Streptozotocin induced diabetes in rats.

Protective effects of medicinal plant against diabetes induced cardiac disorder: A review

ETHNOPHARMACOLOGY RELEVANCE

Nowadays, there is an increase in global tendency to use medicinal plants as preventive and therapeutic agents to manage diabetes and its long-term complications such as cardiovascular disorders owing to their availability and valuable traditional background.

AIM OF STUDY

This review aims to introduce common medicinal plants, which have been demonstrated to have cardioprotective effects on diabetes and their mechanisms of action.

MATERIALS AND METHODS

Online literature databases, including Web of Sciences, PubMed, Science Direct, Scopus and Google Scholar were searched without date limitation by May 2020. The following keywords (natural products or medicinal plants or herbal medicine or herb or extract) and (diabetes or antidiabetic or hyperglycemic) and (cardiomyopathy or heart or cardioprotective or cardiac or cardio) were used, and after excluding non-relevant articles, 81 original English articles were selected.

RESULTS

The surveyed medicinal plants induced cardioprotective effects mostly through increasing antioxidant effects leading to attenuating ROS production as well as by inhibiting inflammatory signaling pathways and related cytokines. Moreover, they ameliorated the Na+/K + ATPase pump, the L-type Ca₂⁺ channel current, and the intracellular ATP. They also reduced cardiac remodeling and myocardial cell apoptosis through degradation of caspase-3, Bax, P53 protein, enhancement of Bcl-2 protein expression as well as downregulation of TGFβ1 and TNFα expression. In addition, the extracts improved cardiac function through increasing EF% and FS% as well as restoring hemodynamic parameters.

CONCLUSIONS

The reviewed medicinal plants demonstrated cardioprotective manifestations in diabetes through intervention with mechanisms involved in the diabetic heart to restore cardiovascular complications.

Potential therapeutic effects of endothelial cells trans-differentiated from Wharton's Jelly-derived mesenchymal stem cells on altered vascular functions in aged diabetic rat model

BACKGROUND

Diabetes mellitus in elderly represents an exceptional subset in the population vulnerable to cardiovascular events. As aging, diabetes mellitus and hypertension share common pathways, an ideal treatment should possess the ability to counter more than one of, if not all, the underlying mechanisms. Stem cells emerged as a potential approach for complicated medical problems. We tested here the possible role of trans-differentiated endothelial cells (ECs) in the treatment of diabetes mellitus in old rats.

METHODS

Mesenchymal stem cells where isolated from umbilical cord Wharton's Jelly and induced to differentiate into endothelial like-cells using vascular endothelial growth factor-enriched media. Thirty aged male Wistar albino rats were used in the present study. Rats were divided (10/group) into: control group (18-20 months old, weighing 350-400 g, received single intraperitoneal injection as well as single intravenous injection via tail vein of the vehicles), aged diabetic group (18-20 months old, weighing 350-400 g, received single intraperitoneal injection of 50 mg/kg streptozotocin, and also received single intravenous injection of saline via tail vein), and aged diabetic + ECs group (18-20 months old, weighing 350-400 g, received single intraperitoneal injection of 50 mg/kg streptozotocin, and also received single intravenous injection of 2*10⁶ MSC-derived ECs in 0.5 ml saline via tail vein) groups. Assessment of SBP, aortic PWV, and renal artery resistance was performed. Serum levels of ET1, ANG II, IL-6, TNF-α, MDA, ROS, and VEGF were evaluated, as well as the aortic NO tissue level and eNOS gene expression. Histopathological and immunostaining assessments of small and large vessels were also performed.

RESULTS

Induction of diabetes in old rats resulted in significant increase in SBP, aortic PWV, renal artery resistance, and serum levels of ET1, ANG II, IL-6, TNF-α, MDA, ROS, and VEGF. While there was significant decrease in aortic NO tissue level and eNOS gene expression in the aged diabetic group when compared to aged control group. ECs treatment resulted in significant improvement of endothelial dysfunction, inflammation and oxidative stress.

CONCLUSION

We report here the potential therapeutic role of trans-differentiated ECs in aged diabetics. ECs demonstrated anti-inflammatory, antioxidant, gene modifying properties, significantly countered endothelial dysfunction, and improved vascular insult.

Effect of olive leaves extract on the antidiabetic effect of glyburide for possible herb-drug interaction

The concomitant use of olive leaves (OL) and glyburide (GLB) is a possible therapy for diabetic patients. However, there is no report about the effect of OL on the antidiabetic effect of GLB till now. In the current study, the possible interaction of olive leaves extract (OLE) with GLB was assessed to determine if there was any pharmacological benefit over GLB alone. Seven groups of male Sprague Dawley rats were used. Normal rats of the 1st group treated with 2 mL/kg of 3% Tween 80 (vehicle). The 2nd–5th groups were diabetic rats received vehicle, GLB (5 mg/kg), OLE low dose and OLE high dose respectively, while the 6th–7th groups administered combinations of GLB plus OLE low dose and GLB plus OLE high dose, respectively. All treatments were administered orally once daily for 8 weeks.

The use of GLB+OLE-500 obviously improved fasting blood glucose (FBG), insulin and glycated hemoglobin (HbA1c) in diabetic rats (95.5 ± 5.55 mg/dL, 6.8 ± 0.16 mg/dL and 6.1 ± 0.29%, respectively) compared to those treated with GLB monotherapy (140.0 ± 6.36 mg/dL, 5.4 ± 0.19 mg/dL and 7.0 ± 0.20%, respectively). The lipid profile [triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)] was significantly improved in diabetic rats exposed to GLB+OLE-500 (35.6 ± 1.51 mg/dL, 48.5 ± 2.74 mg/dL, 25.1 ± 1.21 mg/dL and 17.0 ± 0.82 mg/dL, respectively) in comparison with diabetic group exposed to GLB alone (43.2 ± 2.15 mg/dL, 56.8 ± 2.14 mg/dL, 18.6 ± 0.96 mg/dL, 23.0 ± 1.26 mg/dL, respectively). Additionally, the benefit impacts of GLB+OLE-500GLB+OLE-500 therapy on the antioxidant and lipid peroxidation parameters in the pancreatic tissues of diabetic rats were higher than those of GLB monotherapy. Moreover, GLB plus OLE-500 combination had the greatest effect on restoration of the insulin content of Beta (β) cells and reduction of the glucagon and somatostatin of Alpha (α) and Delta (δ) endocrine cells in the pancreatic islets among the different treatment. The current study suggests that OL and GLB combination could cause herb-drug interactions through modulation of insulin receptor (INR), glucose transporter 2 (Slc2a2) and peroxisome proliferator-activated receptor α (PPAR-α) genes expression in the liver of diabetic rats.

Impact of Ginkgo biloba extract and magnetized water on the survival rate and functional capabilities of pancreatic β-cells in type 2 diabetic rat model

INTRODUCTION

Type 2 diabetes (T2D) is a widely distributed disease that affects large population worldwide. This study aimed to verify the role of Ginkgo biloba (GB) extract and magnetized water (MW) on the survival rate and functional capabilities of pancreatic β-cells in type 2 diabetic rats.

MATERIALS AND METHODS

T2D was induced by feeding the rats on a high-fat diet (20% fat, 45% carbohydrate, 22% protein) for eight weeks followed by intra-peritoneal injection of a single low dose of streptozotocin (25mg/Kg). Forty rats were randomly assigned to four groups (n=10 rats) as follows: non treated control and three diabetic groups. One diabetic group served as a positive control (diabetic), while the other two groups were orally administered with water extract of GB leaves (0.11 g/kg/day) and MW (600 gauss) for four weeks, respectively.

RESULTS

The β-cell mass and insulin expression in these cells increased markedly after both treatments, particularly in GB treated group. In addition, the immune-expression of the two antioxidant enzymes; glutathione and superoxide dismutase 2 (SOD2) in the pancreatic tissue demonstrated a down-regulation in GB and MW treated groups as compared with the diabetic group.

CONCLUSION

A four-week treatment of GB and MW protected pancreatic β-cell cells and improved their insulin expression and antioxidant status in type 2 diabetic rats.

Effect of silver nanoparticles upon the myocardial and coronary vascular function in isolated and perfused diabetic rat hearts

Silver nanoparticles (AgNPs) are promising antibacterial nanomaterials for diagnostic and treatment of diabetes. However, toxicity and adverse cardiac responses induced by AgNPs related to nitric oxide (NO) and oxidative stress (OS) are described. Moreover, little is known about the diabetes influence upon AgNPs-toxicity. The aim of this work was to evaluate cardiovascular function in response to AgNPs through measuring perfusion pressure (PP) and left ventricle pressure (LVP), using perfused hearts from streptozotocin (STZ)-induced diabetic rats and identify the role of NO and OS. High concentrations but not the lower concentrations of AgNPs, promotes increases in PP and LVP, as well as increased OS. Additionally, diabetes alters the classic effects of phenylephrine (Phe) and acetylcholine (ACh). These data suggest that diabetes may intensify AgNPs-cardiotoxicity. Nevertheless, the precise mechanism of action is still under elucidation.

The effect of alogliptin on pulmonary function in obese patients with type 2 diabetes inadequately controlled by metformin monotherapy

BACKGROUND

To observe the effect of alogliptin combined with metformin on pulmonary function in obese patients with type 2 diabetes inadequately controlled by metformin monotherapy (500 mg, bid po, for at least 3 months), and evaluate its efficacy and safety.

METHODS

After a 2-week screening period, adult patients (aged 36-72 years) entered a 4-week run-in/stabilization period. Then, patients were randomly assigned to either the intervention group (n = 55) or the control group (n = 50) for 26 weeks. The patients in the control group were given metformin (1000 mg, bid po) and the patients in the intervention group were given metformin (500 mg, bid po) combined with alogliptin (25 mg, qd po). All the patients received counseling about diet and exercise from a nutritionist during run-in and treatment periods.The primary endpoints were the between-group differences in the changes in pulmonary function parameters (vital capacity [VC]%, forced vital capacity [FVC]%, forced expiratory volume in 1 second (FEV1)%, peak expiratory force [PEF]%, maximal voluntary ventilation [MVV]%, total lung capacity [TLC%], forced expiratory volume in 1 second/forced vital capacity [FEV1/FVC%], diffusing capacity for carbon monoxide of lung [DLCO]%, and diffusing capacity for carbon monoxide of lung/unit volume [DLCO/VA%]) between pretherapy and posttreatment. The secondary endpoints were changes from baseline to week 26 in glycosylated hemoglobinA1c (HbA1c), FPG, 2hPG, homeostasis model assessment insulin resistance (HOMA-IR), waist circumference (WC), and BMI. The tertiary endpoints were the changes from baseline to week 26 in blood-fat (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TG]). The quartus endpoints were the changes from baseline to week 26 in systolic blood pressure (SBP) and diastolic blood pressure (DBP). The 5th endpoints were the changes from baseline to week 26 in oxidative/antioxidative parameters (reactive oxygen species [ROS], malondialdehyde [MDA], superioxide dismutase [SOD], and glutathione peroxidase [GSH-Px]). In addition, safety endpoints were assessed (AEs, clinical laboratory tests, vital signs, and electrocardiographic readings).

RESULTS

Eighty-one patients completed our clinical trial: intervention group (n = 44) and control group (n = 37). At week 26, pulmonary function parameters (VC%, FVC%, FEV1%, PEF%, MVV%, TLC%, FEV1/FVC%, DLCO%, and DLCO/VA%) had increased significantly from pretherapy values in both groups (P < 0.05), and the pulmonary function tests were significantly greater (P < 0.05) in intervention group than in controls posttherapy. Pulmonary function (FVC%, FEV1%, PEF%, TLC%, FEV1/FVC%, DLCO%, and DLCO/VA%) was lower in the group with HbA1c levels ≥8.0 at 26 weeks, but VC%, FEV1%, MVV%, and TLC% were not significantly lower (P > 0.05). Pulmonary function parameters were positively correlated with GSH-Px and SOD and negatively correlated with ROS and MDA. Mean declines in HbA1c, FPG, 2hPG, HOMA-IR, and blood-fat (TC, HDL-C, LDL-C, and TG) were significantly greater (P < 0.05) in intervention group compared with the controls, but mean declines in BMI, WC, and BP (SBP, DBP) did not differ significantly between the 2 groups (P > 0.05). SOD and GSH-Px increased more (P < 0.05) in the intervention group, compared with the controls; ROS and MDA declined more (P < 0.05) in intervention group, as compared with the control group. The most common AEs were gastrointestinal events, headaches, skin-related AEs (mostly pruritic events), and hypoglycemia. The incidences of AEs did not differ significantly (P > 0.05) between the 2 groups except for the headache and skin-related adverse events (the incidence of headache was higher in the intervention group than in controls; P < 0.05). No patient died during the study.

CONCLUSION

In patients with type 2 diabetes mellitus (T2DM) inadequately controlled by metformin monotherapy, the addition of alogliptin contributed to clinically significant increases in pulmonary function through regulating glycemia and improving the imbalance of the oxidative-related substances in the serum, without increasing the incidence of hypoglycemia, dyslipidemia, dysarteriotony, and any notable increase in body weight.

New 1,4-Dihydropyridines Down-regulate Nitric Oxide in Animals with Streptozotocin-induced Diabetes Mellitus and Protect Deoxyribonucleic Acid against Peroxynitrite Action

Diabetes mellitus (DM) and its complications cause numerous health and social problems throughout the world. Pathogenic actions of nitric oxide (NO) are responsible to a large extent for development of complications of DM. Search for compounds regulating NO production in patients with DM is thus important for the development of pharmacological drugs. Dihydropyridines (1,4-DHPs) are prospective compounds from this point of view. The goals of this study were to study the in vivo effects of new DHPs on NO and reactive nitrogen and oxygen species production in a streptozotocin (STZ)-induced model of DM in rats and to study their ability to protect DNA against nocive action of peroxynitrite. STZ-induced diabetes caused an increase in NO production in the liver, kidneys, blood and muscles, but a decrease in NO in adipose tissue of STZ-treated animals. Cerebrocrast treatment was followed by normalization of NO production in the liver, kidneys and blood. Two other DHPs, etaftorone and fenoftorone, were effective in decreasing NO production in kidneys, blood and muscles of diabetic animals. Furthermore, inhibitors of nitric oxide synthase (NOS) and an inhibitor of xanthine oxidoreductase (XOR) decreased NO production in kidneys of diabetic animals. Treatment with etaftorone decreased expression of inducible NOS and XOR in kidneys, whereas it increased the expression of endothelial NOS. In vitro, the studied DHPs did not significantly inhibit the activities of NOS and XOR but affected the reactivity of peroxynitrite with DNA. These new DHPs thus appear of strong interest for treatment of DM complications.

Octaphlorethol A isolated from Ishige foliacea prevents and protects against high glucose-induced oxidative damage in vitro and in vivo

We investigated the protective effect of octaphlorethol A (OPA) isolated from Ishige foliacea against high-glucose-induced oxidative damage, as indicated by reactive oxygen species (ROS) generation, lipid peroxidation, and cell death, in human umbilical vein endothelial cells (HUVECs) and in a zebrafish model. OPA treatment significantly and dose-dependently decreased ROS generation, lipid peroxidation, and cell death in HUVECs and in a zebrafish model. Our results show that OPA can protect HUVECs and zebrafish against high glucose by suppressing intracellular ROS generation, lipid peroxidation, and cell death.

Diabetic cardiomyopathy: mechanisms and new treatment strategies targeting antioxidant signaling pathways

Cardiovascular disease is the primary cause of morbidity and mortality among the diabetic population. Both experimental and clinical evidence suggest that diabetic subjects are predisposed to a distinct cardiomyopathy, independent of concomitant macro- and microvascular disorders. 'Diabetic cardiomyopathy' is characterized by early impairments in diastolic function, accompanied by the development of cardiomyocyte hypertrophy, myocardial fibrosis and cardiomyocyte apoptosis. The pathophysiology underlying diabetes-induced cardiac damage is complex and multifactorial, with elevated oxidative stress as a key contributor. We now review the current evidence of molecular disturbances present in the diabetic heart, and their role in the development of diabetes-induced impairments in myocardial function and structure. Our focus incorporates both the contribution of increased reactive oxygen species production and reduced antioxidant defenses to diabetic cardiomyopathy, together with modulation of protein signaling pathways and the emerging role of protein O-GlcNAcylation and miRNA dysregulation in the progression of diabetic heart disease. Lastly, we discuss both conventional and novel therapeutic approaches for the treatment of left ventricular dysfunction in diabetic patients, from inhibition of the renin-angiotensin-aldosterone-system, through recent evidence favoring supplementation of endogenous antioxidants for the treatment of diabetic cardiomyopathy. Novel therapeutic strategies, such as gene therapy targeting the phosphoinositide 3-kinase PI3K(p110α) signaling pathway, and miRNA dysregulation, are also reviewed. Targeting redox stress and protective protein signaling pathways may represent a future strategy for combating the ever-increasing incidence of heart failure in the diabetic population.

Markers of Oxidative Stress during Diabetes Mellitus

The prevalence of diabetes mellitus is rising all over the world. Uncontrolled state of hyperglycemia due to defects in insulin secretion/action leads to a variety of complications including peripheral vascular diseases, nephropathy, neuropathy, retinopathy, morbidity, and/or mortality. Large body of evidence suggests major role of reactive oxygen species/oxidative stress in development and progression of diabetic complications. In the present paper, we have discussed the recent researches on the biomarkers of oxidative stress during type 2 diabetes mellitus.

Mitochondria as a source and target of lipid peroxidation products in healthy and diseased heart

The heart is a highly oxidative organ in which cardiomyocyte turnover is virtually absent, making it particularly vulnerable to accumulation of lipid peroxidation products (LPP) formed as a result of oxidative damage. Reactive oxygen and nitrogen species are the most common electrophiles formed during lipid peroxidation and lead to the formation of both stable and unstable LPP. Of the LPP formed, highly reactive aldehydes are a well-recognized causative factor in ageing and age-associated diseases, including cardiovascular disease and diabetes. Recent studies have identified that the mitochondria are both a primary source and target of LPP, with specific emphasis on aldehydes in cardiomyocytes and how these affect the electron transport system and Ca(2+) balance. Numerous studies have found that there are functional consequences in the heart following exposure to specific aldehydes (acrolein, trans-2-hexanal, 4-hydroxynonenal and acetaldehyde). Because these LPP are known to form in heart failure, cardiac ischaemia-reperfusion injury and diabetes, they may have an underappreciated role in the pathophysiology of these disease processes. Lipid peroxidation products are involved in the transcriptional regulation of endogenous anti-oxidant systems. Recent evidence demonstrates that transient increases in LPP may be beneficial in cardioprotection by contributing to mitohormesis (i.e. induction of anti-oxidant systems) in cardiomyocytes. Thus, exploitation of the cardioprotective actions of the LPP may represent a novel therapeutic strategy for future treatment of heart disease.