Evaluation of the Antihyperglycemic efficacy of the roots of Ferula orientalis L.: An in vitro to in vivo assessment.

Decoctions of Ferula orientalis L. (Apiaceae), have been traditionally used to lower blood glucose levels (BGLs). After in vitro enzyme inhibition tests on the dichloromethane extracts of the roots (FOD) and the methanol extract of the roots (FOM), isolation studies were carried out on the FOD extract. The anti-hyperglycemic effects of the FOD extract and the pure compounds were studied in mice using the Oral Glucose Tolerance Test (OGTT) and streptozotocin (STZ)-induced diabetes mellitus (DM) models. Molecular docking studies were performed on potent compounds in the binding pockets of enzymes α-glucosidase and α-amylase. The isolations of 11 compounds were isolated from the FOD extract, which comprised teferidine (1), ferutinin (FT) (2), teferin (3), epoxy-jaeschkeanadiol-p-hydroxybenzoate (4), epoxy-jaeschkeanadiol-6-vanillate (5), tovarol-8-angelate (6), leucoferin (7), tovarol-8-p-hydroxybenzoate (8), tovarol-8-vanillate (9), 6-ß-p-hydroxybenzoyloxy-germacra-1(10),4-diene (10), and chimgin (11). Compounds 2 and 8-11 exhibited a higher inhibitory activity on α-glucosidase. In the OGTT, pretreatment with the FOD extract or compound 2 did not alter the BGLs after administration of the glucose solution compared to the control. In the STZ-induced diabetic mice model, no significant difference in the BGLs was observed with the FOD extract (200 mg/kg) or compound 2 (100 mg/kg)-treated diabetic mice compared to the diabetic control mice. The experimental studies all showed that the F. orientalis extract had significant effects on the enzyme systems involved in DM, and it would be appropriate to plan further studies on possible problems of bioavailability of the compound FT and the FOD extract, inadequate dose, and duration of administration.

Impaired exploration induced by type 1 diabetes is related to locomotor activity rather than a reduction in motivation.

Type 1 diabetes mellitus (T1D) is associated with cognitive impairments in humans. A well-established animal model of T1D is induced through the administration of streptozotocin (STZ), a glucose analog that induces pancreatic ß-cell death, resulting in hyperglycemia and cognitive impairment linked to neuroinflammation and oxidative stress. Tumor necrosis factor (TNF)-α, a key inflammatory mediator, is elevated in the central nervous system (CNS) of diabetic animals. In this study, we utilized TNFR1 knockout mice to investigate the role of TNFR1 signaling in short-term T1D-related cognitive impairment. Our findings showed that diabetic animals did not develop cognitive damage within the first 2 weeks of T1D but exhibited reduced exploration in all behavioral tests. Our findings suggest that this reduction in exploration was attributable to motor impairment, as there was no reduction in motivated novelty-seeking behavior. Additionally, deletion of TNFR1 signaling attenuated gait speed impairment in diabetic mice, but did not affect other motor-related or exploratory behaviors.

EndoC-ßH3 pseudoislets are suitable for intraportal transplantation in diabetic mice.

BACKGROUND: Islet or ß-cell transplantation is a therapeutical approach to substitute the insulin-producing cells which are abolished in type 1 diabetes mellitus. The shortage of human islets as well as the complicated and costly isolation process limit the application of these techniques in daily clinical practice. EndoC-ßH is a human ß-cell line that readily forms aggregates termed pseudoislets, providing an alternative to primary human islets or ß-cells. METHODS: EndoC-ßH3 cells were seeded and incubated to form pseudoislets. Their insulin secretion was analyzed by ELISA and compared with cell monolayers. Pseudoislets were transplanted into streptozotocin-treated NMRi nu/nu mice. Blood glucose was monitored before and after transplantation and compared with wild types. Grafts were analyzed by immunohistology. RESULTS: This study shows that EndoC-ßH cells are able to form pseudoislets by aggregation, leading to an enhanced glucose stimulated insulin secretion in vitro. These pseudoislets were then successfully transplanted into the livers of diabetic mice and produced insulin in vitro. Blood glucose levels of the streptozocin-treated recipient mice were significantly decreased when compared to pre-transplantation and matched the levels found in control mice. CONCLUSION: We suggest pseudoislets aggregated from EndoC-ßH cells as a valuable and promising model for islet transplantation research.

Mitigation of Diabetes Mellitus Using Euphorbia helioscopia Leaf Ethanolic Extract by Modulating GCK, GLUT4, IGF, and G6P Expressions in Streptozotocin-Induced Diabetic Rats.

Diabetes mellitus is a metabolic disorder. Synthetic antidiabetics are the commonly used treatment options associated with complications. The objective of this study was to explore the antioxidative and antidiabetic potential of Euphorbia helioscopia whole plant ethanolic extract using in vitro and in vivo models. For that purpose, the antioxidative potential was explored by using 2,2-diphenyl-1-picrylhydrazyl analysis. In vitro antidiabetic potential of the extract was evaluated using amylase inhibitory analysis. In vivo antidiabetic activity of the extract was assessed in diabetic rats using streptozotocin/nicotinamide (60 mg/kg/120 mg/kg) as an inducing agent. Metformin was used as standard. The results indicated the presence of significant quantities of phenolic 82.18 ± 1.28 mgg-1 gallic acid equivalent (GAE) and flavonoid 66.55±1.22 mgg-1 quercetin equivalent (QE) contents in the extract. Quantitation of phytoconstituents exhibited the presence of sinapic acid, myricetin, and quercetin using HPLC analysis. The extract inhibited α-amylase by 84.71%, and an antiglycemic potential of 50.34% was assessed in the OGTT assay. Biochemical analysis demonstrated a reduction in urea, creatinine, cholesterol, low-density lipoprotein, and alkaline phosphatase (p < 0.001) as compared to diabetic control rats at the dose of 500 mg/kg. An upregulation in the expressions of glucokinase, glucose transporter 4, peroxisome proliferator-activated receptor γ, and insulin-like growth factor was observed in treated rats in contrast to G6P expression, which was downregulated upon treatment. In conclusion, this study provided evidence of the antioxidative and antidiabetic potential of E. helioscopia whole plant ethanolic extract through in vitro and in vivo analysis and emphasized its promising role as a natural alternative.

Combination Therapy with Vitamin D and Metformin: A Potential Approach to Mitigate Testicular Dysfunction in Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a multifactorial disease that cannot be linked to a single pathway, causing the observed heterogeneity among T2DM patients. Despite this level of heterogeneity, T2DM is majorly managed by metformin (MET) monotherapy. However, recent findings have associated long-term metformin intake with progressive oxidative pancreatic ß cell damage as the disease progresses. Hence, a significant number of patients treated with MET need an alternate therapy. Hence, identifying drug combinations that can effectively alleviate different diabetes complications would serve as a more promising therapy that can translate into active use. Hence, this study was designed to explore the possible synergistic effect of vitamin D and metformin on T2DM-induced testicular dysfunction. Thirty healthy male Wistar rats (weight: 120-150 g and age: 10 ± 2 weeks) were randomly divided into control, diabetes untreated (HFD+STZ), diabetes + vitamin D (1000 IU/kg), diabetes + metformin (180 mg/kg), and diabetes + vitamin D + metformin. All treatments lasted for 28 days and animals were sacrificed using IP injection of ketamine and xylaxine (40 and 4 mg/kg respectively). Vitamin D improved the ameliorative effect of metformin on T2DM-induced hyperglycemia and lipid dysmetabolism, accompanied by a significant decrease in testicular lactate dehydrogenase and lactate. Also, vitamin D + metformin significantly increased serum luteinizing hormone, follicle-stimulating hormone, testosterone, and testicular 5α reductase activities. Furthermore, vitamin D improved the anti-inflammatory and antioxidant effects of metformin by significantly decreasing T2DM-induced increase in testicular interleukin 1beta, interleukin 6, TNF-α, nitric oxide, and NF-κB and increasing T2DM-induced decrease in interleukin 10, glutathione, superoxide dismutase, catalase, GPx, and Nrf2. Vitamin D enhanced the ameliorative effect of metformin on T2DM-induced testicular dysfunction.

Reductive stress in mitochondria isolated from the carotid body of type 1 diabetic male Wistar rats.

The carotid body (CB) senses changes in arterial O2 partial pressure (pO2) and glucose levels; therefore, it is key for the detection of hypoxia and hypoglycemia. The CB has been suggested to detect pO2 through an increase in reactive oxygen species (ROS) in the mitochondria. However, the mechanism protecting the chemoreceptor cells and their mitochondria from ROS and hyperglycemia is poorly understood. Here we measured glutathione levels in CB mitochondria of control and in streptozotocin (STZ)-induced type 1 diabetic male Wistar rats. We found a dramatic reduction in total glutathione from 11.45 ± 1.30 µmol/mg protein in control rats to 1.45 ± 0.31 µmol/mg protein in diabetic rats. However, the ratio of reduced to oxidized glutathione, a measure of the redox index, was increased in diabetic rats compared to controls. We conclude that the mitochondria of CB chemoreceptor cells in type 1 diabetic male Wistar rats were likely under glutathione-reducing stress.

Therapeutic potential of bark extracts from Macaranga denticulata on renal fibrosis in streptozotocin-induced diabetic rats.

Macaranga denticulata (MD) bark is commonly utilized in traditional medicine for diabetes prevention and treatment. The bark extract of MD is rich in prenyl or farnesyl flavonoids and stilbenes, which possess antioxidant properties. Although data suggest the potential therapeutic benefits of the use of MD in treating diabetic nephropathy (DN), the precise mechanisms underlying MD-initiated protective effects against DN are not well understood. This study aimed to assess the renoprotective properties of MD extract by examining renofibrosis inhibition, oxidative stress, and inflammation utilizing streptozotocin-induced DN male Sprague - Dawley rats. Diabetic rats were intraperitoneally injected with streptozotocin (STZ) to induce diabetes. After 6 days, these rats were orally administered MD extract (200 mg/kg/day) or metformin (200 mg/kg/day) for 14 days. The administration of MD extract significantly lowered blood glucose levels, restored body weight, and reduced urine levels of various biomarkers associated with kidney functions. Histopathological analysis revealed protective effects in both kidneys and pancreas. Further, MD extract significantly restored abnormalities in advanced glycation end products, oxidative stress biomarkers, and proinflammatory cytokine levels in STZ-treated rats. MD extract markedly reduced renal fibrosis biomarker levels, indicating recovery from renal injury, and reversed dysregulation of sirtuins and claudin-1 in the kidneys of rats with STZ-induced diabetes. In conclusion, data demonstrated the renoprotective role of MD extract, indicating plant extract's ability to suppress oxidative stress and regulate proinflammatory pathways during pathological changes in diabetic nephropathy.

Synbiotic supplementation ameliorates anxiety and myocardial ischaemia-reperfusion injury in hyperglycaemic rats by modulating gut microbiota.

Hyperglycaemia, hyperlipidaemia, hypertension and obesity are the main risk factors affecting the development and prognosis of ischaemic heart disease, which is still an important cause of death today. In our study, male Sprague-Dawley rats were fed either a standard diet (SD) or a high fat and high carbohydrate diet (HF-HCD) for 8 weeks and streptozotocin (STZ) was injected at the seventh week of the feeding period. In one set of rats, a mixture of a prebiotic and probiotics (synbiotic, SYN) was administered by gavage starting from the beginning of the feeding period. Experimental myocardial ischaemia-reperfusion (30 min/60 min) was induced at the end of 8 weeks. Hyperglycaemia, hypertension and increased serum low-density lipoprotein levels occurred in SD- and HF-HCD-fed and STZ-treated rats followed for 8 weeks. Increased density of the Proteobacteria phylum was observed in rats with increased blood glucose levels, indicating intestinal dysbiosis. The severity of cardiac damage was highest in the dysbiotic HF-HCD-fed hyperglycaemic rats, which was evident with increased serum creatine kinase-MB (CK-MB), cardiac troponin I (cTnI), tumour necrosis factor-α, and interleukin-6 levels, along with a decrease in ST-segment resolution index. SYN supplementation to either a normal or a high-fat high-carbohydrate diet improved gut dysbiosis, reduced anxiety, decreased CK-MB and cTnI levels, and alleviated myocardial ischaemia-reperfusion injury in hyperglycaemic rats.

Harnessing the therapeutic potential of bone marrow-derived stem cells for sciatic nerve regeneration in diabetic neuropathy.

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that affects the angiogenesis and myelination of peripheral nerves. In this study, we investigated the potential of mesenchymal stem cells (MSCs) transplantation to improve DPN by enhancing angiogenesis and remyelination in the sciatic nerve of streptozotocin (STZ)-induced diabetic female rats. The purpose of this study was to evaluate the therapeutic potential of mesenchymal stem cells as a possiblity for clinical intervention to alleviate the symptoms of diabetic peripheral neuropathy. We examined whether transplanted mesenchymal stem cells can produce new and restored angiogenesis, as well as promoting myelination. Overall, our findings suggest that MSCs transplantation has neuroprotective effects. This is particularly the case for Schwann cells. Transplantation may stimulate angiogenesis as well as remyelination of the sciatic nerve in experimentally-induced diabetic peripheral neuropathy. Behavioral assays, histological analysis, and molecular techniques were used to assess the effects of MSCs transplantation. Our results demonstrate that in diabetic rats signs of neuropathy were reversed following a single administration of bone marrow-derived MSCs. Morphological and morphometric analysis of the sciatic nerve revealed that diabetic rats displayed structural alterations that were attenuated with MSCs transplantation.Immunostaining analysis showed increased expression of S100 and VEGF in the sciatic nerve following MSCs transplantation. Western blotting analysis also revealed elevated levels of VEGF and CD31 in rats treated with MSCs compared to diabetic rats.

Mitigation of biochemical alterations in streptozotocin-induced gestational diabetes in rats through mesenchymal stem cells and olive leaf extract.

Treatment with mesenchymal stem cells (MSCs) is a new promising therapeutic approach with substantial very auspicious potential. They have been shown to protect various played a role in protecting organs from damage. This current study aims to evaluate the impact of the treatment of olive leaf extract (OLE), bone marrow-derived (BM-MSCs), and their combination on hepatotoxicity in pregnant rats with diabetes. METHODS: Animals were divided into five groups (10 pregnant rats each) as follows: control, GDM group, and OLE group (rats received streptozotocin (STZ) at a dose of 35 mg/kg body weight). GD + OLE set (pregnant rats were administered OLE at a dose of 200 mg extract/kg of body weight). GD + MSCs group (pregnant rats treated with MSCs). GD + OLE + MSCs group (pregnant rats were treated with both MSCs and OLE). RESULTS: STZ induced significant changes in liver parameters, lipid profile, and oxidative stress. Treatment with OLE, BM-MSCs, and their combination significantly ameliorated STZ-induced liver damage and oxidative stress. STZ resulted in a significant change in liver parameters, lipid profile, and oxidative stress. OLE, BM-MSC, and combination have significantly improved STZ-induced deterioration in liver and improved oxidative stress. CONCLUSIONS: The findings demonstrate that OLE and BM-MSCs have beneficial effects in mitigating diabetes-related liver alterations. These outcomes showed that OLE and BM-MSC have beneficial effects in alleviating diabetes-related alterations in the liver.

Saroglitazar Enhances Memory Functions and Adult Neurogenesis via Up-Regulation of Wnt/ß Catenin Signaling in the Rat Model of Dementia.

Peroxisome proliferator-activated receptors (PPARs) have emerged as a promising target for the treatment of various neurodegenerative disorders. Studies have shown that both PPAR α & γ individually modulate various pathophysiological events like neuroinflammation and insulin resistance, which are known to variedly affect neurogenesis. Our study aimed to evaluate the effect of saroglitazar (SGZR), a dual PPAR agonist, on adult neurogenesis and spatial learning and memory, in intracerebroventricular streptozotocin (ICV STZ)-induced dementia in rats. We have found that SGZR at the dose of 4 mg/kg per oral showed significant improvement in learning and memory compared to ICV STZ-treated rats. A substantial increase in neurogenesis was observed in the subventricular zone (SVZ) and the dentate gyrus (DG), as indicated by an increase in the number of 5-bromo-2'-deoxyuridine (BrdU)+ cells, BrdU+ nestin+ cells, and doublecortin (DCX)+cells. Treatment with SGZR also decreased the active form of glycogen synthase kinase 3ß (GSK3ß) and hence enhanced the nuclear translocation of the ß-catenin. Enhanced expression of Wnt transcription factors and target genes indicates that the up-regulation of Wnt signaling might be involved in the observed increase in neurogenesis. Hence, it can be concluded that the SGZR enhances memory functions and adult neurogenesis via the upregulation of Wnt ß-catenin signaling in ICV STZ-treated rats.

Evaluation of terpenes rich Hura crepitans extract on glucose regulation and diabetic complications in STZ-induced diabetic rats.

The continual increase in global diabetic statistics portends decreased productivity and life spans, thus making it a disease of concern requiring more effective and safe therapeutic options. While several reports on antidiabetic plants, including Hura crepitans, are available, there is still a dearth of information on the holistic antidiabetic properties of H. crepitans and its associated complications. This study evaluated the antidiabetic potential of methanolic extract of Hura crepitans using in vitro, in vivo, and in silico approaches. The extract revealed a dose-dependent in vitro effect, with a 47.97 % and 65.34 % decrease in the fasting blood sugar levels of streptozotocin (STZ) induced diabetic rats at 150 and 300 mg/kg BW, respectively. Likewise, the extract increased serum and pancreatic insulin levels, and significantly ameliorated neuronal oxidative stress and inflammation by reducing the expression levels of cholinesterase, NF-κB, and COX-2 in the brain of hyperglycemic rats. Serum dyslipidemia, liver, and kidney biomarker indices, and hematological alterations in diabetic rats were also significantly attenuated by the extract. Several constituents, mainly terpenes, were identified in the extract. To further predict the drug-likeness, pharmacokinetics, and binding properties of the compounds, in silico analysis was conducted. Ergosta-2,24-dien-26-oicacid,18-(acetyloxy)-5,6-epoxy-4, 22-dihydroxy-1-oxo-,delta.-lactone-4.beta., displayed the highest docking scores for acetylcholinesterase, butyrylcholinesterases, alpha-amylase, and nuclear factor-kB with values of -12.4, -10.9, -10.3, and -9.4 kcal/mol, while ergost-25-ene-6,12-dione,3,5-dihydroxy-, (3.beta.,5.alpha.) topped for cyclooxygenase-2 (-9.0 kcal/mol). The top-ranked compounds also presented significant oral drug-likeness, pharmacokinetics, and safety properties. Altogether, our data provide preclinical evidence of the potential of Hura crepitans in ameliorating diabetes and its associated complications.

Secreted chemokines reveal diverse inflammatory and degenerative processes in the intervertebral disc of the STZ-HFD mouse model of Type 2 diabetes.

The chronic inflammation present in type 2 diabetes causes many chronic inflammatory comorbidities, including cardiovascular, renal, and neuropathic complications. Type 2 diabetes is also associated with a number of spinal pathologies, including intervertebral disc (IVD) degeneration and chronic neck and back pain. Although confounding factors such as obesity are thought to increase the loads to the musculoskeletal system and subsequent degeneration, studies have shown that even after adjusting age, body mass index, and genetics (e.g. twins), patients with diabetes suffer from disproportionately more IVD degeneration and back pain. Yet the tissue-specific responses of the IVD during diabetes remains relatively unknown. We hypothesize that chronic diabetes fosters a proinflammatory microenvironment within the IVD that accelerates degeneration and increases susceptibility to painful disorders. To test this hypothesis, we evaluated two commonly used mouse models of diabetes - the leptin-receptor deficient mouse (db/db) and the chronic high-fat diet in mice with impaired beta-cell function (STZ-HFD). The db/db is a genetic model that spontaneous develop diabetes through hyperphagia, while the STZ-HFD mouse first exhibits rapid obesity development under HFD and pronounced insulin resistance following streptozotocin administration. Both animal models were allowed to develop sustained diabetes for at least twelve weeks, as defined by elevated hemoglobin A1C, hyperglycemia, and glucose intolerance. Following the twelve-week period, the IVDs were extracted in quantified in several measures including tissue-specific secreted cytokines, viscoelastic mechanical behavior, structural composition, and histopathologic degeneration. Although there were no differences in mechanical function or the overall structure of the IVD, the STZ-HFD IVDs were more degenerated. More notably, the STZ-HFD model shows a significantly higher fold increase for eight cytokines: CXCL2, CCL2, CCL3, CCL4, CCL12 (monocyte/macrophage associated), IL-2, CXCL9 (T-cell associated), and CCL5 (pleiotropic). Correlative network analyses revealed that the expression of cytokines differentially regulated between the db/db and the STZ-HFD models. Moreover, the STZ-HFD contained a fragmented and modular cytokine network, indicating greater complexities in the regulatory network. Taken together, the STZ-HFD model of type 2 diabetes may better recapitulate the complexities of the chronic inflammatory processes in the IVD during diabetes.

Diabetes mellitus exacerbates inflammation in a murine model of ligature-induced peri-implantitis: A histological and microtomographic study.

AIM: To investigate the influence of diabetes mellitus (DM) in a murine model of peri-implantitis (PI). MATERIALS AND METHODS: Twenty-seven 4-week-old C57BL/6J male mice had their first and second maxillary left molars extracted. Eight weeks later, one machined implant was placed in each mouse. Four weeks after osseointegration, the mice were divided into three groups: (a) control (C), (b) PI and (c) DM + PI. DM was induced by streptozotocin (STZ) administration. After DM induction, PI was induced using ligatures for 2 weeks. The hemimaxillae were collected for micro-CT and histological analyses. The primary outcomes consisted of linear (mm) and volumetric (mm3) bone loss. Secondary outcomes were based on histological analysis and included inflammatory infiltrate, osteoclastic activity, matrix organization, composition and remodelling. Data are presented as means ± SEM. Statistical analyses were performed using one-way ANOVA, followed by Tukey's test. RESULTS: Gingival tissue oedema was detected in the PI and DM + PI groups. Micro-CT showed significantly increased linear and volumetric bone loss in the DM + PI group compared to the C and PI groups. H&E staining showed greater inflammatory response and bone resorption in the PI and DM + PI groups than in the C group. The DM + PI group had significantly higher osteoclast numbers than the C and PI groups. Picrosirius red stained less for types I and III collagen in the PI and DM + PI groups than in the C group. There was a significant increase in monocyte/macrophage (CD-11b) counts and matrix metalloproteinases (MMP-2 and MMP-8) marker levels and a significant decrease in the matrix metalloproteinases inhibition marker (TIMP-2) levels in the DM + PI group compared to the C and PI groups. CONCLUSIONS: DM exacerbates PI-induced soft-tissue inflammation, matrix degradation and bone loss.

Hyperglycemia-independent neonatal streptozotocin-induced retinopathy (NSIR) in rats.

Introduction: Chemicals, such as MNU (N-methyl-N-nitrosourea) and NaIO3 (sodium iodate), are widely used to induce retinal degeneration in rodents. Streptozotocin (STZ) is an analog of N-acetyl glucosamine in which an MNU moiety is linked to a hexose and has a special toxic effect on insulin-producing pancreatic ß-cells. It is commonly used to induce hyperglycemia to model diabetes. While intracerebroventricular injection of STZ can produce Alzheimer's disease independent of hyperglycemia, most retinal studies using STZ focus on the effects of hyperglycemia on the retina, but whether STZ has any impact on retinal cells independent of hyperglycemia is unknown. We aimed to investigate the role of cytotoxicity of STZ in rat retina. Methods: Intravitreal or subcutaneous injection of STZ was performed on newborn rats. Electroretinogram (ERG) and H&E staining investigated retinal function and morphological changes. Retinal cell types, cell death, proliferation, inflammation, and angiogenesis were studied by immunostaining. RNA sequencing was performed to examine the transcriptome changes of retinal cells after intravitreal injection of STZ. Results: Intravitreal (5 µg or 10 µg) or subcutaneous (30 mg/kg) injection of STZ at the early stage of newborn rats couldn't induce hyperglycemia but caused NSIR (Neonatal STZ-induced retinopathy), including reduced ERG amplitudes, retinal rosettes and apoptosis, cell cycle arrest, microglial activation, and delayed retinal angiogenesis. STZ did not affect the early-born retinal cell types but significantly reduced the late-born ones. Short-term and long-term hyperglycemia had no significant effects on the NSIR phenotypes. RNA sequencing revealed that STZ induces oxidative stress and activates the p53 pathway of retinal cells. Locally or systemically, STZ injection after P8 couldn't induce SINR when all retinal progenitors exit the cell cycle. Conclusion: NSIR in rats is independent of hyperglycemia but due to STZ's direct cytotoxic effects on retinal progenitor cells. NSIR is a typical reaction to STZ-induced retinal oxidative stress and DNA damage. This significant finding suggests that NSIR may be a valuable model for studying retinal progenitor DNA damage-related diseases, potentially leading to new insights and treatments.

Dose-Dependent Attenuation of the Efficacy of Clitoria ternatea by Cobalt Oxide Nanoparticles Against Diabetes-Induced Cognitive Impairment.

Diabetes mellitus is a metabolic disorder caused by insulin deficiency, insulin resistance, genetic alterations, and oxidative stress. The high glucose levels may impair the functioning of nerve cells, leading to neurodegenerative diseases, including cognitive impairment. Clitoria ternatea has various pharmacological activities, including antioxidant, anti-inflammatory, antidiabetic, and neuroprotective effects. The present study evaluates the efficacy of fresh flower aqueous extract of Clitoria ternatea against diabetes-induced cognitive impairment. The challenges in delivering drugs targeting the brain possess the limitations of crossing the blood-brain barrier. Metal nanoparticles are considered the most reliable brain drug delivery systems. Considering the neurotoxicity of cobalt oxide, whether it can be used to improve brain delivery is also evaluated. Cobalt oxide nanoparticles (Co3O4 NPs) of fresh flower aqueous extract of Clitoria ternatea are prepared by green synthesis and characterized. The effect of these nanoparticles is compared with Clitoria ternatea extract against Streptozotocin (STZ)-induced cognitive impairment. The behavioral, biochemical, in vivo antioxidant, total thiol content, estimation of proinflammatory cytokines, acetylcholine esterase, and nitrite levels in the brain of STZ-induced diabetic rats revealed that cobalt oxide nanoparticles showed neurotoxicity, whereas C. ternatea showed neuroprotective effect and also improved the cognitive function. The lower dose of cobalt oxide nanoparticles of C. ternatea (2 mg/kg) exhibited a neuroprotective and cognition improvement effect. However, the higher dose (4 mg/kg) of cobalt oxide nanoparticles of C. ternatea showed a neurotoxic effect. Since Co3O4 NPs are neuroprotective at low doses, they can be used for neuroprotective actions. However, dose optimization studies are required.

Comparison of Metabolic Changes after 6 Months of High-Carbohydrate Diet or High-Fat Diet with Low Dose Streptozotocin Injection in Rats.

We compared 2 models of metabolic syndrome in rats: high-fat diet (58% calories) with single streptozotocin injection at a dose of 25 mg/kg and replacement of water with 20% fructose solution. The model with fructose solution did not cause the main signs of metabolic syndrome over 24 weeks: concentrations of glucose, triglycerides, cholesterol, weight, and BP did not significantly differ from the control group (standard diet). At the same time, single streptozotocin administration was followed by the development of persistent hyperglycemia, hypertriglyceridemia, hypercholesterolemia, and signs of visceral obesity. High-fat diet combined with injection of streptozotocin in a low dose can be considered a more representative model of metabolic syndrome in humans.

Polysaccharide fraction from Triplostegia glandulifera Wall and its renoprotective effect in streptozotocin-induced diabetic mice by attenuating oxidative stress.

Triplostegia glandulifera Wall (T. glandulifera) is an ethnomedicine commonly used by ethnic minorities in Yunnan, China, to treat kidney disease. However, there are few reports on the renoprotective effects of this substance, and the active ingredients remain unclear. In this study, we extracted the polysaccharide fractions TGB and TGC using the water extraction-alcohol precipitation method and determined their molecular weight (Mw) and monosaccharide composition. The study investigated the protective effects of TGB and TGC fractions against diabetic nephropathy (DN) using an in vitro high glucose-induced HRMCs model and an in vivo STZ-induced diabetic mouse model. HPLC analysis revealed that TGB contained D-galacturonic acid, D-glucose, D-galactose, and D-arabinose, and had a lower Mw than TGC. In vitro, TGB showed concentration-dependent antioxidant activity and effectively reduced abnormal proliferation and while attenuating oxidative stress in HRMCs. In mice with diabetes, TGB corrected the dysregulation of glucose-lipid metabolism and alleviated oxidative stress in the kidneys. Additionally, it improved renal function and reduced renal tissue damage. The study suggests that the low Mw polysaccharides (TGB) have better activity against DN through the antioxidative stress mechanism.

Anti-Diabetic and Insulinotropic Effects of p­Anisic Acid in High­Fat Diet and Streptozotocin Induced Type-2 Diabetic Rats.

PURPOSE: To evaluate the antidiabetic effect of p-anisic acid (p­AA) against type 2 diabetes mellitus (T2DM). METHODS: Thirty-six male rats were utilized for the study. The animals were provided with the high­fat diet (HFD) and T2DM was induced through 35 mg/kg streptozotocin (STZ). Subsequently, the animals were allocated to 6 groups and subjected to the treatments for 4 weeks followed by a 2-week observation. Three treatment groups were administered with p­AA (25 mg/kg, 50 mg/kg or 100 mg/kg). Glibenclamide (3 mg/kg) was provided to the standard control group. The normal control and disease control groups were supplied with 0.1% carboxymethyl cellulose (CMC). Subsequently, the effects of treatment on body weight (BW), blood glucose level (BGL), glycosylated haemoglobin (HbA1c), insulin, and lipid parameters were measured and the pancreas was isolated for histopathology. RESULTS: A statistically significant (P-value < 0.001) increase in BW was observed in the p-AA (50 mg/kg and 100 mg/kg) groups. The BGL decreased significantly (P­value < 0.001) in p­AA groups. p-AA significantly (P­value < 0.001) regulated the levels of HbA1c and serum insulin and lipid parameters. A notable improvement in the morphology of the pancreas was observed. CONCLUSION: Treatment with p-AA exhibited significant antidiabetic effects against STZ­HFD­induced T2DM.

Daidzein ameliorates peripheral neuropathy in Sprague Dawley rats.

Neuropathy is the most common disorder comprising peripheral nerve damage in diabetic patients. Prolonged hyperglycaemia and oxidative stress cause metabolic imbalance and are the key reasons for the development of diabetic neuropathy. Daidzein, a soy isoflavone possesses potent anti-hyperglycaemic and antioxidant activity. The present study aims to check the protective effect of Daidzein in diabetic neuropathy in rats. The experimental animal model involved induction of diabetes in rats by intraperitoneal injection of streptozotocin (55 mg/kg). Following confirmation of diabetes, the diabetic rats were subjected to oral treatment with varying doses of Daidzein (25, 50, and 100 mg/kg) and pregabalin (30 mg/kg) for a duration of 4 weeks, initiated 6 weeks after diabetes induction. Results indicated that Daidzein treatment led to a significant reduction in plasma glucose levels and an improvement in body weight among diabetic animals. Moreover, Daidzein demonstrated a positive impact on sensory functions, as evidenced by the effect on tail withdrawal and response latency. Mechanical hyperalgesia and allodynia, common symptoms of diabetic neuropathy, were also significantly reduced with both Daidzein and pregabalin treatment. Notably, nerve conduction velocities exhibited improvement following the administration of Daidzein and pregabalin. Further investigation into the molecular mechanisms revealed that Daidzein treatment resulted in a notable enhancement of antioxidant enzyme levels and a reduction in the overexpression of NOX-4 in the sciatic nerve. This suggests that Daidzein's therapeutic effect is associated with the inhibition of oxidative stress via NOX-4. In summary, the findings of study suggests that, Daidzein treatment significantly attenuated diabetic neuropathy by inhibiting oxidative stress via NOX-4 inhibition.