Chrysin-loaded PEGylated liposomes protect against alloxan-induced diabetic neuropathy in rats: the interplay between endoplasmic reticulum stress and autophagy.

BACKGROUND: Diabetic neuropathy (DN) is recognized as a significant complication arising from diabetes mellitus (DM). Pathogenesis of DN is accelerated by endoplasmic reticulum (ER) stress, which inhibits autophagy and contributes to disease progression. Autophagy is a highly conserved mechanism crucial in mitigating cell death induced by ER stress. Chrysin, a naturally occurring flavonoid, can be found abundantly in honey, propolis, and various plant extracts. Despite possessing advantageous attributes such as being an antioxidant, anti-allergic, anti-inflammatory, anti-fibrotic, and anticancer agent, chrysin exhibits limited bioavailability. The current study aimed to produce a more bioavailable form of chrysin and discover how administering chrysin could alter the neuropathy induced by Alloxan in male rats. METHODS: Chrysin was formulated using PEGylated liposomes to boost its bioavailability and formulation. Chrysin PEGylated liposomes (Chr-PLs) were characterized for particle size diameter, zeta potential, polydispersity index, transmission electron microscopy, and in vitro drug release. Rats were divided into four groups: control, Alloxan, metformin, and Chr-PLs. In order to determine Chr- PLs' antidiabetic activity and, by extension, its capacity to ameliorate DN, several experiments were carried out. These included measuring acetylcholinesterase, fasting blood glucose, insulin, genes dependent on autophagy or stress in the endoplasmic reticulum, and histopathological analysis. RESULTS: According to the results, the prepared Chr-PLs exhibited an average particle size of approximately 134 nm. They displayed even distribution of particle sizes. The maximum entrapment efficiency of 90.48 ± 7.75% was achieved. Chr-PLs effectively decreased blood glucose levels by 67.7% and elevated serum acetylcholinesterase levels by 40% compared to diabetic rats. Additionally, Chr-PLs suppressed the expression of ER stress-related genes (ATF-6, CHOP, XBP-1, BiP, JNK, PI3K, Akt, and mTOR by 33%, 39.5%, 32.2%, 44.4%, 40.4%, 39.2%, 39%, and 35.9%, respectively). They also upregulated the miR-301a-5p expression levels by 513% and downregulated miR-301a-5p expression levels by 65%. They also boosted the expression of autophagic markers (AMPK, ULK1, Beclin 1, and LC3-II by 90.3%, 181%, 109%, and 78%, respectively) in the sciatic nerve. The histopathological analysis also showed that Chr-PLs inhibited sciatic nerve degeneration. CONCLUSION: The findings suggest that Chr-PLs may be helpful in the protection against DN via regulation of ER stress and autophagy.

Platelet-Rich Plasma (PRP) Mitigates Kidney Dysfunction in Alloxan-Induced Diabetic Mice via Modulation of Renal Iron Regulatory Genes.

Kidney dysfunction is a prevalent complication of diabetes mellitus, contributing significantly to diabetes-related morbidity and mortality. We aim to explore whether platelet-rich plasma administration can modulate iron regulation mechanism within the kidney, thereby mitigating renal dysfunction associated with diabetes. Albino mice with an average body weight of 20 ± 5 g were randomly divided into five groups (N = 50; n = 10): Control Group, PRP Group, diabetic group (DG), treated group A (TA), and treated group B (TB). A single intraperitoneal dose of alloxan (160 mg/kg of body weight) was administered to mice in the DG and in both treated groups. Upon confirmation of diabetes, the DG was left untreated, while PRP treatment (0.5 ml/kg of body weight) was administered to the TA and TB groups for two and four weeks, respectively. Histological examinations of kidney tissues revealed notable signs of damage in DG, which were subsequently improved upon PRP treatment. Likewise, PRP treatment restored the changes in liver enzymes, oxidative stress biomarkers and serum electrolytes in both treated groups. Furthermore, there was an observed upregulation of iron regulatory genes, such as Renin, Epo, Hepc, Kim1, and Hfe, in the DG, accompanied by a downregulation of Tfr1 and Fpn; however, Dmt1 and Dcytb1 expression remained unaltered. Treatment with PRP restored the expression of iron regulatory genes in both treated groups. This study concluded that PRP treatment effectively restored the renal histochemistry and the expression of renal iron regulatory genes in an alloxan-induced diabetic mice model.

Effect of heterologous platelet-rich plasma on liver and modulation of glucose metabolism and Wnt signalling pathways in diabetic mice.

BACKGROUND: The current study was designed to highlight the effects of heterologous platelet-rich plasma (PRP) on deteriorated hepatic tissues and impaired glucose metabolism of alloxan-induced diabetic mice. METHODS: 30 male mice were divided into a control (CG), PRP (PG), diabetic (DG), and two treated groups (T1G and T2G). PG was given PRP treatment (0.5 ml/kg body weight) twice a week for four weeks. DG, T1G and T2G were given alloxan (150 mg/kg) to induce diabetes. After confirmation, PRP treatment was given to T1G and T2G for two and four weeks respectively while DG was left untreated. Upon completion of the said experimental period, liver samples were taken for histological and gene expression analyses. RESULTS: The study found that the liver tissue of the DG group showed signs of damage, including hepatocyte ballooning, sinusoid dilatation, and collagen deposition. However, these changes were significantly reduced in both T1G and T2G groups. The expression of several genes related to liver function was also affected, with upregulation of Fbp1 and Pklr, and downregulation of Pck1 in the DG group. PRP treatment restored Fbp1 expression and also increased the expression of glycolytic pathway genes Hk1 and Gck, as well as Wnt signalling pathway genes Wnt2, Wnt4, and Wnt9a in both treated groups. CONCLUSION: Current study revealed that heterologous PRP may partly alleviate high glucose levels in diabetics possibly by mediating glucose metabolism via inhibition of Wnt signalling pathway.

Determination of Hypoglycemic, Hypolipidemic and Nephroprotective Effects of Berberis Calliobotrys in Alloxan-Induced Diabetic Rats.

Many plants of the Berberis genus have been reported pharmacologically to possess anti-diabetic potential, and Berberis calliobotrys has been found to be an inhibitor of α-glucosidase, α-amylase and tyrosinase. Thus, this study investigated the hypoglycemic effects of Berberis calliobotrys methanol extract/fractions using in vitro and In vivo methods. Bovine serum albumin (BSA), BSA-methylglyoxal and BSA-glucose methods were used to assess anti-glycation activity in vitro, while in vivo hypoglycemic effects were determined by oral glucose tolerance test (OGTT). Moreover, the hypolipidemic and nephroprotective effects were studied and phenolics were detected using high performance liquid chromatography (HPLC). In vitro anti-glycation showed a significant reduction in glycated end-products formation at 1, 0.25 and 0.5 mg/mL. In vivo hypoglycemic effects were tested at 200, 400 and 600 mg/kg by measuring blood glucose, insulin, hemoglobin (Hb) and HbA1c. The synergistic effect of extract/fractions (600 mg/kg) with insulin exhibited a pronounced glucose reduction in alloxan diabetic rats. The oral glucose tolerance test (OGTT) demonstrated a decline in glucose concentration. Moreover, extract/fractions (600 mg/kg) exhibited an improved lipid profile, increased Hb, HbA1c levels and body weight for 30 days. Furthermore, diabetic animals significantly exhibited an upsurge in total protein, albumin and globulin levels, along with a significant improvement in urea and creatinine after extract/fractions administration for 42 days. Phytochemistry revealed alkaloids, tannins, glycosides, flavonoids, phenols, terpenoids and saponins. HPLC showed the presence of phenolics in ethyl acetate fraction that could be accountable for pharmacological actions. Therefore, it can be concluded that Berberis calliobotrys possesses strong hypoglycemic, hypolipidemic and nephroprotective effects, and could be a potential therapeutic agent for diabetes treatment.

Phenolics Extracted from Jasminum sambac Mitigates Diabetic Cardiomyopathy by Modulating Oxidative Stress, Apoptotic Mediators and the Nfr-2/HO-1 Pathway in Alloxan-Induced Diabetic Rats.

Diabetes mellitus is a chronic metabolic disorder defined as hyperglycemia and pancreatic ß-cell deterioration, leading to other complications such as cardiomyopathy. The current study assessed the therapeutic effects of phenolic acids extracted from Jasminum sambac phenols of leaves (JSP) against diabetes-induced cardiomyopathy in rats. The rats were divided into four groups, with each group consisting of 20 rats. The rats were given intraperitoneal injections of alloxan monohydrate (150 mg/kg) to induce diabetes. The diabetes-induced groups (III and IV) received treatment for six weeks that included 250 and 500 mg/kg of JSP extract, respectively. In the treated rats, the results demonstrated that JSP extract restored fasting glucose, serum glucose, and hyperlipidemia. Alloxan induced cardiomyopathy, promoted oxidative stress, and altered cardiac function biomarkers, including cardiac troponin I, proBNP, CK-MB, LDH, and IMA. The JSP extract-treated rats showed improved cardiac function indicators, apoptosis, and oxidative stress. In diabetic rats, the mRNA expression of caspase-3, BAX, and Bcl-2 was significantly higher, while Bcl-2, Nrf-2, and HO-,1 was significantly lower. In the treated groups, the expression levels of the BAX, Nrf-2, HO-1, Caspase-3, and Bcl-2 genes were dramatically returned to normal level. According to our findings, the JSP extract prevented cardiomyopathy and heart failure in the hyperglycemic rats by improving cardiac biomarkers and lowering the levels of hyperlipidemia, oxidative stress, apoptosis, hyperglycemia, and hyperlipidemia.

CARBOHYDRATES METABOLISM IN THE BLOOD OF RATS WITH IMPAIRED GLUCOSE TOLERANCE UNDER LONG TERM MELATONIN INJECTIONS.

OBJECTIVE: The aim: To determine the influence of melatonin on the glucose level and content of malondialdehyde, activities of pyruvate kinase and glucose-6-phosphate dehydrogenase enzymes in the blood; histochemical features of glycogen distribution in liver of rats with impaired glucose tolerance. PATIENTS AND METHODS: Materials and methods: Diabetes in rats was induced by intra-abdominal injection of a 5% solution of alloxan monohydrate at the rate of 170 mg/kg of body weight. Four days after animals were divided into rats with impaired glucose tolerance and melatonin-group with impaired glucose tolerance (5 mg/ kg «Sigma¼ USA, daily and intraperitoneal for 42 days starting from 5th day). Impaired glucose tolerance was determined by measurement of glucose profiles - fasting <5.6 mmol/l; postprandial (2h post-load) 7.8 - 11.0 mmol/l. Histochemical examination of the liver was performed according to the standard method of PAS-reaction staining. Statistical analysis was performed using Statistica 10 StatSoft Inc. RESULTS: Results: Pyruvate kinase activity in erythrocytes and optical density of glycogen in hepatocytes of animals with impaired glucose tolerance decreased on 18% and 11%, activity of glucose-6-phosphate dehydrogenase and content of malondialdehyde increased on 35% and 23%, respectively compared with the control. We have reached the recovery of the pyruvate kinase and normalization of glucose-6-phosphate dehydrogenase activities, malondialdehyde levels, glucose profiles in the blood as well as glycogen distribution in the liver caused by melatonin injections. CONCLUSION: Conclusions: We have determined that long term melatonin injections did better glucose tolerance in rats.

Comparison of post-mortem vitreous fluid and blood glucose levels in diabetes-induced rabbit models.

Background: Diabetes is a common systemic disease in the world. Acute complications of diabetes may cause sudden unexpected deaths. Analysis done in vitreous fluid which is more protected and less contaminated by bacteria comparing to blood will produce more accurate results. Aim: Thus, we aimed to diagnose diabetes by comparing glucose levels of post mortem blood and vitreous fluid in death cases. Materials and Methods: A total of 17 New Zealand-type rabbits were divided into hyperglycemia (8), hypoglycemia (8), and control group (1). Rabbits were monitored for 5 days after experimental diabetes induction, and samples were taken at the point of death. Later rabbits were left in their environment, and samples were taken again at the post mortem first day. Mean blood glucose levels of hyperglycemia and hypoglycemia group were in diabetic range. Results: Blood glucose levels of hyperglycemic rabbits were measured as 512 ± 52,1 mg/dl, while vitreous glucose levels were 518,3 ± 76,8 mg/dl at the point of death. After one day, levels were measured as 433,9 ± 59,3 mg/dl and 329,8 ± 86,6 mg/dl. Blood glucose levels of hypoglycemic rabbits were measured as 39 ± 3,8 mg/dl, while vitreous glucose levels were 53,4 ± 13,9 mg/dl at the point of death. After one day, levels were measured as 36 ± 4,2 mg/dl and 1,6 ± 0,6 mg/dl. After analysis, there was a statistically significant difference between day 0 and 1 vitreous levels of hypoglycemia group. Conclusion: It can be clearly seen that vitreous fluid samples should be taken in judicial cases with sudden unexpected deaths like diabetes. This will contribute to identification cause of death.

A novel in vitro approach to test the effectiveness of fish oil in ameliorating type 1 diabetes.

Diabetes type 1 (T1D) characterized by destruction of pancreatic ß-cells results in inadequate insulin production and hyperglycaemia. Generation of reactive oxygen species and glycosylation end-products stimulates toxic impacts on T1D. Dietary w-3 fatty acids present in Fish oil (FO) might be helpful in the prevention of oxidative stress and lipid peroxidation, thus, beneficial against T1D. But how the cellular secretion from ß-cells under influence of FO affects the glucose homeostasis of peri-pancreatic cells is poorly understood. In the current study, we aimed to introduce an in vitro model for T1D and evaluate its effectiveness in respect of alloxan treatment to pancreatic Min6 cells. We use alloxan in the Min6 pancreatic ß-cell line to induce cellular damage related to T1D. Further treatment with FO was seen to prevent cell death by alloxan and induce mRNA expression of both insulin 1 and insulin 2 isoforms under low-glucose conditions. From the first part of the study, it is clear that FO is effective to recover Min6 cells from the destructive effect of alloxan, and it worked best when given along with alloxan or given after alloxan treatment regime. FO-induced secretion of molecules from Min6 was clearly shown to regulate mRNA expression of key enzymes of carbohydrate metabolism in peri-pancreatic cell types. This is a pilot study showing that an improved in vitro approach of using Min6 along with muscle cells (C2C12) and adipose tissue cells (3T3-L1) together to understand the crosstalk of molecules could be used to check the efficacy of an anti-diabetic drug.

ß-cells regeneration by WL15 of cysteine and glycine-rich protein 2 which reduces alloxan induced ß-cell dysfunction and oxidative stress through phosphoenolpyruvate carboxykinase and insulin pathway in zebrafish in-vivo larval model.

BACKGROUND: Pancreatic ß-cells are susceptible to oxidative stress, leading to ß-cell death and dysfunction due to enhanced ROS levels and type 2 diabetes. To inhibit the ß-cells damages induced by the oxidative stress, the present study investigates the beneficial effect of various peptides (WL15, RF13, RW20, IW13 and MF18) of immune related proteins (cysteine and glycine-rich protein 2, histone acetyltransferase, vacuolar protein sorting associated protein 26B, serine threonine-protein kinase and CxxC zinc finger protein, respectively). Also, the molecular mechanism of WL15 from cysteine and glycine-rich protein 2 on ß-cell regeneration was identified through PEPCK and insulin pathway. MATERIALS AND METHODS: In this study, a total of five peptides including WL15, RF13, RW20, IW13, and MF18 were derived from immune-related proteins such as cysteine and glycine-rich protein 2, histone acetyltransferase, vacuolar protein sorting associated protein 26B, serine threonine-protein kinase and CxxC zinc finger protein, respectively. These protein sequences were obtained from an earlier constructed transcriptome database of a teleost Channa striatus. The identified peptides were evaluated for their antioxidant as well as antidiabetic activity. Based on the in silico analysis and in-vitro screening experiments, WL15 was predicted to have better antioxidant and antidiabetic activity among the five different peptides. Therefore, WL15 alone was further analyzed for apoptosis, antioxidant capacity, glucose metabolism, and gene expression performance, which was investigated on the alloxan (500 µM) induced zebrafish in vivo larval model. RESULTS: The results showed alloxan exposure to zebrafish larvae for a day, the ROS was generated in the ß-cells. Interestingly, WL15 treatment showed a protective effect by reducing the toxicity of alloxan exposed zebrafish larvae by increasing their survival and heart rate. Moreover, WL15 reduced the intracellular ROS level and apoptosis in alloxan-induced larvae. The superoxide anion and lipid peroxidation levels are also reduced by improving the glutathione content after the WL15 treatment. Besides, WL15 treatment increased the proliferation rate of ß-cells and decreased the glucose level. Further, the gene expression studies revealed that WL15 treatment normalized the PEPCK expression while upregulating the insulin expression in alloxan exposed larvae. CONCLUSION: Overall, the findings indicate that WL15 of cysteine and glycine-rich protein 2 can act as a potential antioxidant for type 2 diabetes patients in respect of improving ß-cell regeneration.

Superoxide-producing thermostable associate from the small intestines of control and alloxan-induced diabetic rats: quantitative and qualitative changes.

BACKGROUND: NADPH oxidase 1 (Nox1), which is highly expressed in the colon, is thought to play a potential role in host defense as a physical and innate immune barrier against commensal or pathogenic microbes in the gastrointestinal epithelium. Diabetes can be caused by several biological factors, including insulin resistance is one of them. Alloxan is widely used to induce insulin-dependent diabetes in experimental animals. Alloxan increases the generation of reactive oxygen species as a result of metabolic reactions in the body, along with a massive increase in cytosolic calcium concentration. METHODS: Using a universal method, a superoxide radical (О2-)-thermostable associate between NADPH-containing lipoprotein (NLP) and NADPH oxidase (Nox)- NLP-Nox was isolated and purified from the small intestine (SI) of control (C) and alloxan-induced diabetic (AD) albino rats. RESULTS: In comparison to the C indices, in AD in the SI, an increase in the specific content of NLP-Nox associate and a decrease in the stationary concentration of produced О2- in liquid phase (in solution) and gas phase (during blowing by oxygen of the NLP-Nox solution) were observed. The NLP-Nox of SI associate in C and AD rats produced О2- by an immediate mechanism, using NLP as a substrate. The phenomenon of the hiding of the optical absorption maxima of the Nox in oxidized states at pH10,5 was observed in the composition of these SI associates of the C and AD rat groups. The characteristic absorption maxima of the «hidden¼ Nox were observed under these conditions after reduction by potassium dithionite. CONCLUSION: Thus, at AD, the decrease in the stationary concentration of produced О2- in the solution and gas phase was compensated for by an increase in the specific amount of associate. In addition,  the decrease in the stationary concentration of produced О2- by NLP-Nox associates at AD can be linked to a decrease in the level of NADPH in NLP-Nox composition. This could be used as a new mechanism of AD pathogenesis.

Biological Evaluation of 3-Azaspiro[Bicyclo[3.1.0]Hexane-2,5'-Pyrimidines] as Potential Antitumor Agents.

A series of heterocyclic compounds containing spirofused barbiturate and 3-azabicyclo[3.1.0]hexane frameworks have been studied as potential antitumor agents. Antiproliferative activity of products was screened in human erythroleukemia (K562), T lymphocyte (Jurkat), and cervical carcinoma (HeLa) as well as mouse colon carcinoma (CT26) and African green monkey kidney epithelial (Vero) cell lines. The most effective among the screened compounds show IC50 in the range from 4.2 to 24.1 µM for all tested cell lines. The screened compounds have demonstrated a significant effect of the distribution of HeLa and CT26 cells across the cell cycle stage, with accumulation of cells in SubG1 phase and induced apoptosis. It was found, using a confocal microscopy, that actin filaments disappeared and granular actin was distributed diffusely in the cytoplasm of up to 90% of HeLa cells and up to 64% of CT26 cells after treatment with tested 3-azaspiro[bicyclo [3.1.0]hexane-2,5'-pyrimidines]. We discovered that the number of HeLa cells with filopodium-like membrane protrusions was reduced significantly (from 91% in control cells to 35%) after treatment with the most active compounds. A decrease in cell motility was also noticed. Preliminary in vivo experiments on the impact of the studied compounds on the dynamics of CT26 tumor growth in Balb/C mice were also performed.

In Vitro and In Vivo Antidiabetic Activity, Phenolic Content and Microscopical Characterization of Terfezia claveryi.

Terfezia claveryi (T. claveryi) is used by traditional healers in the Middle East region to treat several diseases, including diabetes. The present study evaluated the total phenolic and investigated the blood-glucose-lowering potential of different aqueous extracts of this selected truffle using in vitro and in vivo models. The phytochemical profile was examined using UPLC-MS. The macerate and the microwave-assisted extract were the richest in phenolic compounds. All T. claveryi extracts exhibited a remarkable α-glucosidase inhibitory effect in vitro, with an IC50 of 2.43, 3.26, 5.18 and 3.31 mg/mL for the aqueous microwave-assisted extract macerate, infusion and decoction, respectively. On the other hand, in the high-fat diet alloxan-induced diabetic mice model, all tested crude aqueous extracts exhibited a significant antihyperglycemic activity (p < 0.05). Four hours after the administration of the 250 mg/kg dose, the macerate was able to induce a 29.4% blood-glucose-lowering effect compared to a 24.8% reduction induced by the infusion, which was sustained for a further two hours. The hypoglycemic effect (29.3% and 32.4%) was also recorded six hours after the administration of the single dose 500 mg/kg of the macerate and the infusion, respectively. Truffle extracts exhibited antidiabetic activity both in vitro and in vivo, providing a rationale for the traditional use as a natural hypoglycemic.

Chronically administered Agave americana var. marginata extract ameliorates diabetes mellitus, associated behavioral comorbidities and biochemical parameters in alloxan-induced diabetic rats.

Introduction: Diabetes mellitus causes hyperglycemia and associated complications to the brain. In current study, the traditionally reported remedial claims of Agave americana var. marginata has been scientifically investigated in diabetic rats. Methodology: The methanolic extract of leaves of Agave americana var. marginata (Aa.Cr) was characterized for total phenols, flavonoids, and antioxidant potential through in-vitro testing. The rats chronically pre-treated with Aa.Cr (400 and 600 mg/kg) for 45 days were challenged with alloxan-induced hyperglycemia. The dose-dependent effects of Aa.Cr on blood glucose levels and body weights were compared with diabetic rats using glibenclamide (0.6 mg/kg) as a standard. The animals were tested for diabetes-associated neurological comorbidities through behavioral and biochemical evaluation. Results: The phenols and flavonoids enriched Aa.Cr caused a significant dose-dependent hypoglycemic effect. Aa.Cr showed protection from comorbid anxiety, depression and cognitive impairment as compared to diabetic rats. The alanine aminotransferase, total cholesterol, triglycerides and low-density lipoprotein were prominently reduced, and high-density lipoprotein was increased in rats treated with Aa.Cr. Moreover, the oxidative stress in isolated brains was reduced by Aa.Cr. Conclusion: These findings suggest that Aa.Cr is enriched with antioxidant and anti-inflammatory phytoconstituents valuable for diabetes and related neurological complications.

Effect of liraglutide on microcirculation in rat model with absolute insulin deficiency.

INTRODUCTION: The investigations of angiotropic effects of liraglutide are an issue of significant scientific and practical interest. The successful application of liraglutide has been shown in glycemic control in patients with the type 2 diabetes mellitus (DM), but the effect of liraglutide in patients with type 1 DM has not been completely studied yet in clinical practice. Therefore, the present study is aimed to investigate the effect of liraglutide which is agonist of glucagon-like peptide-1 receptors, on microcirculation in white outbred rats with the alloxan-induced diabetes. MATERIALS AND METHODS: The study was performed with 70 white outbred rats, divided into 4 groups: 1) control group (intact animals (Control)); 2) comparison group (diabetes mellitus (DM)) - animals with the alloxan-induced diabetes; 3) experimental group no. 1 (liraglutide low dose (LLD)) - animals with the alloxan-induced diabetes, which were injected by liraglutide at dosage of 0.2 mg/kg of animal weight per a day; 4) experimental group no. 2 (liraglutide high dose (LHD)) - animals with the alloxan-induced diabetes, which were injected by liraglutide at dosage of 0.4 mg/kg of animal weight per a day. The carbohydrate metabolism disorders, the microcirculation of posterior paw skin, as well as the concentration of catecholamines and markers of endothelial alteration in blood were estimated at the 42nd day of the experiment in the comparison and experimental groups. RESULTS: It was found that the correction of carbohydrate metabolism by liraglutide is succeeded by the normalization of skin perfusion of posterior paw skin of the experimental animals. Recovery of microcirculation is associated with a decrease in vascular tone and stimulation of endothelium-dependent vasodilation, caused by simultaneous decrease of catecholamines, endothelin-1 and asymmetric dimethylarginine (ADMA) concentrations in blood serum. At the same time, the administration of liraglutide on the background of insulin-deficiency results in decrease of endothelial cell alteration markers concentration in blood, such as sE-selectin, syndecan-1, and vascular endothelial growth factor (VEGF). CONCLUSION: Administration of liraglutide leads to the normalization of the carbohydrate metabolism simultaneously with the correction of microcirculation in rats with the absolute insulin deficiency. The demonstrated recovery of microcirculation by liraglutide, which represents an analogue of glucagon-like peptide-1, provides new prospects for its approval as a potential drug for pathogenetic correction of microcirculatory disorders in patients with the type 1 DM.

Emerging roles of protein O-GlcNAcylation in cardiovascular diseases: Insights and novel therapeutic targets.

Cardiovascular diseases (CVDs) are the leading cause of death globally. While the major focus of pharmacological and non-pharmacological interventions has been on targeting disease pathophysiology and limiting predisposing factors, our understanding of the cellular and molecular mechanisms underlying the pathogenesis of CVDs remains incomplete. One mechanism that has recently emerged is protein O-GlcNAcylation. This is a dynamic, site-specific reversible post-translational modification of serine and threonine residues on target proteins and is controlled by two enzymes: O-linked ß-N-acetylglucosamine transferase (OGT) and O-linked ß-N-acetylglucosaminidase (OGA). Protein O-GlcNAcylation alters the cellular functions of these target proteins which play vital roles in pathways that modulate vascular homeostasis and cardiac function. Through this review, we aim to give insights on the role of protein O-GlcNAcylation in cardiovascular diseases and identify potential therapeutic targets in this pathway for development of more effective medicines to improve patient outcomes.

Anti-diabetogenic and in vivo antioxidant activity of ethanol extract of Dryopteris dilatata in alloxan-induced male Wistar rats.

AIMS: Oxido-inflammatory stress has been implicated as the main targets in alleviating diabetic complications induced by hyperglycaemia. Dryopteris dilatata: a bioactive plant serves great medicinal benefits in ethnopharmacology to ameliorate pathological conditions. This study investigated the protective effects of ethanol extract of Dryopteris dilatata (EEDD) in alloxan-induced diabetic rats through mechanism involving inhibition of oxidative stress and liver and kidney inflammatory markers. METHODOLOGY: Male Wistar rats were made diabetic via alloxan monohydrate (100 mg/kg) administration intraperitoneally. Diabetic rats were post-treated with EEDD (800 mg/kg) and Metformin (50 mg/kg) orally for two weeks. Fasting blood sugar (FBS), body and organ weight change, markers of oxidative stress, liver and kidney inflammation were evaluated. RESULTS: Our results revealed that EEDD significantly reduced alloxan-induced hyperglycaemia in the diabetic rats after 5, 10 and 15 days of treatment. Markers of oxidative injury were also significantly ameliorated in the pancreas, liver and kidney of the diabetic rats following treatment with EEDD. However, liver and kidney injury markers were significantly attenuated with marked decreased organ weight in the diabetic rats after treatment with EEDD. CONCLUSION: Here in, we found that Dryopteris dilatata could be used as nutraceuticals in the prevention and treatment of diabetes and its related complications through positively modulating oxidative stress and liver and kidney inflammatory markers.

A system-level approach to investigate alloxan-induced toxicity in microtubule-binding protein to lead type 2 diabetes mellitus.

Microtubule-associated protein tau (MAPT) is a key protein, which is mainly identified as an essential factor for microtubule dynamics and neuronal outgrowth. Though tau has several functions, regulation of insulin signaling is one among them to control type 2 diabetes. Abnormal expression of tau protein leads to hyperphosphorylation and is known as tauopathies. The presence of alloxan occurs in refined wheat flour, especially in various baking products such as parotta, a well-known South Indian dish. In this study, the reduced form of alloxan called dialuric acid can enter the beta cells of islets of Langerhans and binds MAPT to induce toxicity by hyperphosphorylating the tau protein, which ultimately causes destruction to pancreatic beta cells, and it leads to diabetes mellitus. Here, the toxic effects of dialuric acid targeting MAPT through in silico computational predictions have been investigated. The 3D structure of MAPT protein was constructed through I-Tasser, and it has been refined and validated by GalaxyRefine and PROCHECK. The structure of ligand was retrieved from PubChem. Molecular docking was accomplished by AutoDock 4.2 software, and the results indicate the strong binding affinity between dialuric acid and MAPT protein, and it showed a binding free energy (∆G) of - 3.72 kcal/mol. Dialuric acid binds with the active region SER 232 of MAPT whereby it hyperphosphorylates the protein to become toxic. Also, ADMET results strongly suggest that the compound dialuric acid possesses toxic property, and similarly, Ames test confirmed that it was found to be mutagenic. Thus, our results strongly revealed that dialuric acid was found to be toxic which could be able to damage the beta cells of the pancreas and abates insulin signaling, and finally, it leads to DM.

Efficacy of Caffeic Acid on Diabetes and Its Complications in the Mouse.

Diabetic dyslipidemia and hyperglycemia contribute to excessive reactive oxygen species (ROS) production, leading to deleterious complications, such as nephropathy, atherosclerosis and cardiac dysfunction, and target major organs in the body. The aim of this study was to investigate the effect of caffeic acid (CA) on mouse weight and survival, serum level of fasting blood glucose (FBG), serum lipid parameters and atherogenic indices, oxidative damage in blood, liver and kidney tissue, pathophysiological changes and their function markers in healthy and alloxan-induced type 1 diabetic mice. Diabetes was induced in mice with a single intravenous injection of alloxan (75 mg kg-1). Two days later, CA (50 mg kg-1) was given intraperitoneally for seven days in diabetic mice. Diabetes affected glucose level, lipid profile, hematological and biochemical parameters, induced DNA damage and apoptotic/necrotic death in whole blood cells, liver and kidney, leading to weight loss and a decreased lifespan. CA treatment of diabetic mice revealed a protective effect on the liver and kidney, hypoglycemic and hypolipidemic properties and high protection against atherogenic outcomes. The obtained results suggest that CA is a safe and potent agent against diabetes that acts as an effective antioxidant in reducing serum glucose, lipid profile and atherogenic indices, leading to increased lifespan in mice.

In Vitro Alpha-Amylase and Alpha-Glucosidase Inhibitory Activity and In Vivo Antidiabetic Activity of Withania frutescens L. Foliar Extract.

Withania frutescens L. is a wild perennial woody plant used by the local population for diverse therapeutic purposes. This work aims to study for the first time the potential inhibitory effect of this plant hydroethanolic extract on α-amylase and α-glucosidase activities using in vitro methods and its antidiabetic and antihyperglycemic activities using alloxan-induced diabetic mice as a model for experimental diabetes. Two doses were selected for the in vivo study (200 and 400 mg/kg) and glibenclamide, a well-known antidiabetic drug (positive control) in a subacute study (28 days) where the antihyperglycemic activity was also assessed over a period of 12 h on diabetic mice. The continuous treatment of diabetic mice with the extract of Withania frutescens for 4 weeks succeeded to slowly manage their high fasting blood glucose levels (after two weeks), while the antihyperglycemic test result revealed that the extract of this plant did not control hyperglycemia in the short term. No toxicity signs or death were noted for the groups treated with the plant extract, and it shows a protective effect on the liver and kidney. The in vitro assays demonstrated that the inhibition of alpha-amylase and alpha-glucosidase might be one of the mechanisms of action exhibited by the extract of this plant to control and prevent postprandial hyperglycemia. This work indicates that W. frutescens have an important long term antidiabetic effect that can be well established to treat diabetes.

[Concentration of VEGF-A in the intraocular fluid of rats with alloxan model of diabetes mellitus]. / Kontsentratsiya VEGF-A vo vnutriglaznoi zhidkosti krys s alloksanovoi model'yu sakharnogo diabeta.

PURPOSE: To study the changes in the concentration of vascular endothelial growth factor A (VEGF-A) in the intraocular fluid (IOF) of rats with alloxan model of diabetes mellitus (DM) on insulin therapy at different time points. MATERIAL AND METHODS: The alloxan model of DM was simulated in 197 rats by a single intraperitoneal injection of 100 mg/kg alloxan hydrate. The animals were divided into 3 groups 7 days after administration of alloxan hydrate. The main group consisted of animals with alloxan model of DM, which begain receiving single daily intraperitoneal injections of insulin at a dose of 0.9 U/kg body weight. The comparison group included animals with alloxan model of DM, which did not receive the therapy. The control group consisted of healthy animals. The experimental animals were withdrawn from the study 1 and 4 months after the start of insulin therapy. The concentration of VEGF-A was determined in 80-90 µL of intraocular fluid collected from both eyes of each animal. RESULTS: At 1 month, the VEGF-A concentration in the intraocular fluid in the study group (n=17; 140 [136; 210] pg/mL) was statistically significantly higher than in the comparison group (n=20; 72 [58; 86] pg/mL; pm-u<0.0004), and in the control group (n=16; 76 [62.5; 88] pg/mL; pm-u=0.0045). The comparison group did not have statistically significant differences from the control group (pm-u=0.9979). At 4 months, the VEGF-A concentration in the intraocular fluid in the study group (n=18) was 84.8 [61.1; 93.2] pg/mL, in the comparison group (n=16) - 66.4 [54.4; 73.75] pg/mL. The VEGF-A concentration in the intraocular fluid in the study group at 4 months was statistically significantly lower than in the study group at 1 month (pm-u<0.0044). CONCLUSION: Insulin therapy causes a statistically significant increase in the concentration of VEGF-A in the intraocular fluid of rats with alloxan model of DM after 1 month, but after 4 months of the therapy the VEGF-A concentration falls back to the initial values.