Quantification of mangiferin in streptozotocin-induced diabetic rat plasma using UPLC-MS/MS: Pharmacokinetic assessment of Gentiana rhodantha extract after oral administration.

Mangiferin, a key bioactive constituent in Gentiana rhodantha, has a favorable impact on reducing blood sugar. A selective and sensitive UPLC MS/MS approach was developed for determining mangiferin in diabetic rats. Employing acetonitrile protein precipitation, chromatographic separation utilized a 2.1×50 mm, 3.5µm C18 column with a mobile phase of 0.1% formic acid aqueous and 5mM ammonium acetate (A, 45%) and acetonitrile (B, 55%) at a 0.5mL min-1 flow rate. Quantification, employing the multiple reaction monitoring (MRM) mode, focused on precursor-to-product ion transitions at m/z 447.1→271.1 for baicalin m/z and 421.0→301.0 for mangiferin. Calibration curves demonstrated linearity in the 1.00~100ng/mL range, with a lower quantification limit for rat plasma set at 1.00ng/mL. Inter- and intra-day accuracies spanned -9.1% to 8.5% and mangiferin mean recovery varied from 82.3% to 86.7%. The adeptly utilized UPLC-MS/MS approach facilitated the exploration of mangiferin pharmacokinetics in diabetic rats.

Assessment of anti-hyperglycemic and anti-hyperlipidemic effects of thiazolidine-2,4-dione derivatives in HFD-STZ diabetic animal model.

Type 2 diabetes mellitus (T2DM) is a chronic endocrine/metabolic disorder characterized by elevated postprandial and fasting glycemic levels that result in disturbances in primary metabolism. In this study, we evaluated the metabolic effects of thiazolidine-2,4-dione derivatives in Wistar rats and Swiss mice that were fed a high-fat diet (HFD) for 4 weeks and received 90 mg/kg of streptozotocin (STZ) intraperitoneally as a T2DM model. The HFD consisted of 17% carbohydrate, 58% fat, and 25% protein, as a percentage of total kcal. The thiazolidine-2,4-dione derivatives treatments reduced fasting blood glucose (FBG) levels by an average of 23.98%-50.84%, which were also improved during the oral starch tolerance test (OSTT). Treatment with thiazolidine-2,4-dione derivatives also improved triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), and total cholesterol levels (P < 0.05). The treatment intake has also shown a significant effect to modulate the altered hepatic and renal biomarkers. Further treatment with thiazolidine-2,4-dione derivatives for 28 days significantly ameliorated changes in appearance and metabolic risk factors, including favorable changes in histopathology of the liver, kidney, and pancreas compared with the HFD/STZ-treated group, suggesting its potential role in the management of diabetes. Thiazolidine-2,4-dione derivatives are a class of drugs that act as insulin sensitizers by activating peroxisome proliferator-activated receptor-gamma (PPAR-γ), a nuclear receptor that regulates glucose and lipid metabolism. The results of this study suggest that thiazolidine-2,4-dione derivatives may be a promising treatment option for T2DM by improving glycemic control, lipid metabolism, and renal and hepatic function.

Preparation of bio-synthesized Ag nanoparticles and assessment of their antidiabetic and antioxidant potential against STZ-induced diabetic albino rats.

Bio-synthesized silver nanoparticles (AgNPs) were successfully obtained using the leaf extract from Ventilago maderaspatana. Extensive analysis was conducted to evaluate the physical and chemical characteristics of the bioderived AgNPs. XRD analysis confirmed their cubic structure, and revealed a well-defined size distribution with average crystallite size of 11.7 nm. FE-SEM and TEM images visually supported the observed size range. The presence of plant-mediated phytochemicals on the surface of AgNPs was confirmed through DLS, FTIR, and TGA/DTA studies. To assess their antidiabetic potential, rats were induced with streptozotocin, resulting in elevated levels of biochemical parameters associated with diabetes. Conversely, serum insulin levels (2.50 ± 0.55) and glucokinase activity (64.50 ± 8.66) decreased. However, treatment with AgNPs demonstrated a dose-dependent reduction in blood glucose, total protein, albumin, and HbA1c levels, effectively restoring them to normal ranges. Moreover, the treatment significantly increased insulin levels (7.55 ± 0.63) and glucokinase activity (121.50 ± 4.60), indicating the antidiabetic potential of V. maderaspatana-mediated AgNPs. Notably, the exitance of phytochemicals, like flavonoids and phenols, on the surface of AgNPs facilitated their ability to neutralize reactive oxygen species (ROS) through electron donation. This property enhanced their overall antidiabetic efficiency.

Wound healing activity of Salvia huberi ethanolic extract in streptozocin-induced diabetic rats.

Objective: The aim of this study was to examine the in vivo wound healing potential of Salvia huberi Hedge (endemic to Turkey) on excision and incision wound models in diabetic rats. Method: Male Wistar albino rats, 3-4 months old and weighing 180-240g were used. The animals were randomly divided into five groups including Control, Vehicle and Fito reference, and two different concentrations (0.5% and 1% weight/weight (w/w)) of ethanol extract of Salvia huberi were investigated in both wound models on streptozocin-induced diabetic rats using macroscopic, biomechanical, biochemical, histopathological, genotoxic and gene expression methods over both seven and 14 days. Fito cream (Tripharma Drug Industry and Trade Inc., Turkey) was used as the reference drug. Results: A total of 60 rats were used in this study. Salvia huberi ointments at 0.5% and 1% (w/w) concentrations and Fito cream showed 99.3%, 99.4% and 99.1% contraction for excision wounds, and 99.9%, 97.0% and 99% contraction for incision wounds, respectively. In Salvia huberi ointments and Fito cream groups, re-epithelialisation increased dramatically by both day 7 and day 14 (p<0.05). By day 14, low hydroxyproline and malondialdehyde (MDA) levels, and high glutathione (GSH) levels were observed in the Salvia huberi ointment groups. After two application periods, damaged cell percent and genetic damage index values and micronucleus frequency of Salvia huberi ointment treatment groups were lower than Control and Vehicle groups (p<0.001). A growth factor expression reached a high level by day 7 in the Control group; in Salvia huberi-treated groups it was decreased. Conclusion: The study showed that application of Salvia huberi ointments ameliorated the healing process in diabetic rats with excisional and incisional wounds and may serve as a potent healing agent.

Systematic assessment of streptozotocin-induced diabetic metabolic alterations in rats using metabolomics.

Purpose: Type 1 diabetes is characterized by elevated blood glucose levels, which negatively impacts multiple organs and tissues throughout the body, and its prevalence is on the rise. Prior reports primarily investigated the serum and urine specimen from diabetic patients. However, only a few studies examined the overall metabolic profile of diabetic animals or patients. The current systemic investigation will benefit the knowledge of STZ-based type 1 diabetes pathogenesis. Methods: Male SD rats were arbitrarily separated into control and streptozotocin (STZ)-treated diabetic rats (n = 7). The experimental rats received 50mg/kg STZ intraperitoneal injection daily for 2 consecutive days. Following 6 weeks, metabolites were assessed via gas chromatography-mass spectrometry (GC-MS), and multivariate analysis was employed to screen for differentially expressed (DE) metabolites between the induced diabetic and normal rats. Results: We identified 18, 30, 6, 24, 34, 27, 27 and 12 DE metabolites in the serum, heart, liver, kidney, cortex, renal lipid, hippocampus, and brown fat tissues of STZ-treated diabetic rats, compared to control rats. Based on our analysis, the largest differences were observed in the amino acids (AAs), B-group vitamin, and purine profiles. Using the metabolic pathway analysis, we screened 13 metabolic pathways related to the STZ-exposed diabetes pathogenesis. These pathways were primarily AA metabolism, followed by organic acids, sugars, and lipid metabolism. Conclusion: Based on our GC-MS analysis, we identified potential metabolic alterations within the STZ-exposed diabetic rats, which may aid in the understanding of diabetes pathogenesis.

Assessment of redox state and biochemical parameters of salivary glands in streptozotocin-induced diabetic male rats treated with mate tea (Ilex paraguariensis).

OBJECTIVE: The study aimed to assess the effects of mate tea [Ilex paraguariensis] on the redox state and biochemical parameters of salivary glands in diabetic male rats. DESIGN: Twenty-four male Wistar rats (3 months old) were randomly divided into groups (n = 8 per group): control rats that received water (C); diabetic rats that received water (D); diabetic rats treated with mate tea (DMT). The treated streptozotocin-induced diabetic rats were given mate tea powder by intragastric gavage at a dose of 20 mg/kg daily for 28 days. Content of total protein, amylase, oxidative lipid damage, measured as thiobarbituric acid reactive substances (TBARs), oxidative protein damage, measured as protein carbonyl, total antioxidant capacity, uric acid, reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were examined by the spectrophotometric method in the parotid and submandibular glands. RESULTS: The D group showed lower total protein, amylase, TBARs, protein carbonyl, total antioxidant capacity, GSH, uric acid, and GPx than the C group in both salivary glands, as well as higher SOD and CAT activities. The DMT group showed higher total protein, amylase, total antioxidant capacity, GSH, uric acid, and GPx than the D group in both salivary glands. Moreover, mate tea increased SOD in the parotid gland and CAT in the submandibular gland of diabetic rats but did not influence TBARs and protein carbonyl in either salivary gland compared to D group. CONCLUSION: Mate tea increased tissue protein synthesis and improved antioxidant defenses in the salivary glands of streptozotocin-induced diabetic male rats.

Assessment of antidiabetic effect of 4-HIL in type 2 diabetic and healthy Sprague Dawley rats.

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by chronic hyperglycemia and insulin resistance. 4-hydroxyisoleucine (4-HIL) is a non-proteinogenic amino acid isolated from the fenugreek seeds and has enormous pharmacological activities. The present study was undertaken to investigate the antihyperglycemic effect of 4-HIL in streptozotocin (STZ)-induced diabetic rats. Moreover, its toxicity was evaluated in vitro and in vivo employing human embryonic kidney cells (HEK-293) and healthy rats, respectively. In experiment 1, STZ-induced diabetic male rats were subjected to an oral treatment of 4-HIL (100 mg/kg), while experiment 2 deals with the effects of 4-HIL on healthy male and female rats following oral administration. The treatment (experiment 1) declined the elevated blood glucose level, feed intake, and increased body weight(s). Additionally, blood glucose impairment was improved as observed by OGTT and IPGT tests. Pancreatic histopathology revealed mild changes in the 4-HIL group. Moreover, experiment 2 showed increased body weight, normal blood glucose levels (male-106.06 ± 7.49 mg/dl and female-100.06 ± 14.69 mg/dL), hematological parameters, and histopathological profiles in the treatment group. 4-HIL did not affect the viability of HEK-293 cells, and no signs of toxicity were observed in healthy rats. Therefore, the study concludes that 4-HIL has potential antihyperglycemic activity without any toxic effects.

Female mouse model of diabetes mellitus induced by streptozotocin and high-carbohydrate high-fat diet.

With the improvement of people's living standards and rapid economic development, the incidence of diabetes mellitus (DM) is increasing in most parts of the world. DM presents an important potential threat to human health. In the present study, a model of diabetes in female mice was established, and fasting blood glucose was detected at week 4, after which the biochemical profiles were evaluated by histopathological analysis. The success rate of modeling in the normal control (NC) group and the low/ middle/high-dose streptozotocin (STZ) group were 0, 0, 25% and 60%, respectively. In the middle-dose and high-dose STZ groups, the liver index was increased significantly compared with the NC group (p⟨0.05). The blood biochemical indicators of total cholesterol and low density lipoprotein cholesterol in three STZ injection groups were as follows: alanine aminotransferase and aspartate transaminase in middle- and high-dose STZ groups, high-density lipoprotein cholesterol and serum creatinine in the high-dose STZ group, and blood urea nitrogen in the middle-dose STZ group were significantly increased (p⟨0.05). The level of total triglycerides was lower, obviously, in the high-dose STZ group than in the NC group (p⟨0.05). The mice showed marked steatosis, green-dyed fiber tissue coloring in varying degrees, and the contour of the hepatic lobules basically disappeared in STZ injection groups. The results suggest that to establish a diabetes model for female ICR mice, the optimum dose of STZ is 100 mg/kg.

Fabrication and Biological Assessment of Antidiabetic α-Mangostin Loaded Nanosponges: In Vitro, In Vivo, and In Silico Studies.

Type 2 diabetes mellitus has been a major health issue with increasing morbidity and mortality due to macrovascular and microvascular complications. The urgent need for improved methods to control hyperglycemic complications reiterates the development of innovative preventive and therapeutic treatment strategies. In this perspective, xanthone compounds in the pericarp of the mangosteen fruit, especially α-mangostin (MGN), have been recognized to restore damaged pancreatic ß-cells for optimal insulin release. Therefore, taking advantage of the robust use of nanotechnology for targeted drug delivery, we herein report the preparation of MGN loaded nanosponges for anti-diabetic therapeutic applications. The nanosponges were prepared by quasi-emulsion solvent evaporation method. Physico-chemical characterization of formulated nanosponges with satisfactory outcomes was performed with Fourier transform infra-red (FTIR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Zeta potential, hydrodynamic diameter, entrapment efficiency, drug release properties, and stability studies at stress conditions were also tested. Molecular docking analysis revealed significant interactions of α-glucosidase and MGN in a protein-ligand complex. The maximum inhibition by nanosponges against α-glucosidase was observed to be 0.9352 ± 0.0856 µM, 3.11-fold higher than acarbose. In vivo studies were conducted on diabetic rats and plasma glucose levels were estimated by HPLC. Collectively, our findings suggest that MGN-loaded nanosponges may be beneficial in the treatment of diabetes since they prolong the antidiabetic response in plasma and improve patient compliance by slowly releasing MGN and requiring less frequent doses, respectively.

Assessment of metals induced histopathological and gene expression changes in different organs of non-diabetic and diabetic rats.

Diabetes is a complex metabolic disorder and different environmental toxicants including heavy metals have been involved in diabetes induction. Therefore, assessment of the environmental risk factors and heavy metals induced toxicity have become critical for reducing the consequences of metals pollutants. Previously, we reported heavy metals induced nephrotoxicity in non-diabetic and diabetic rats. Here, we extended our analysis by examining the heavy metals induced organs (heart, kidney, liver, pancreas, and spleen) damage in diabetic and non-diabetic Wistar rats using histopathology and quantitative real-time PCR (qRT-PCR). Following the generation of the diabetic rat model, the animals were exposed to heavy metals including lead (Pb), arsenic (As), manganese (Mn) and cadmium (Cd). Both non-diabetic and diabetic rats were exposed to heavy metals for 30 days and subsequently, the heart, kidney, liver, pancreas and spleen tissues were examined. Heavy metal treatment resulted in irregularly arranged myofibrils and vacuolization in the heart tissue of metal treated groups as evident from hematoxylin and eosin (H & E) staining. The kidney tissue of rats treated with heavy metals showed tubular degeneration, fibrosis, hemorrhage, and vacuolation. The liver of the heavy metals treated rats exhibited cellular degeneration and necrosis. The pancreatic tissue of streptozotocin injected untreated and metal treated rats revealed severe degeneration, necrosis, degranulation, shrinkage, and depression in the islets of Langerhans. Increased red pulp area and congestion were observed in the spleen of the metal mixture treated non-diabetic and diabetic rats. In line with the histological data, the qRT-PCR analysis showed downregulated expression of Bcl2 and upregulation of Caspase-3 in non-diabetic and diabetic metal treated rats as compared to the non-diabetic untreated rats. In conclusion, the present study revealed, diabetic rats are more prone to metal alone as well as metal mixture induced organ damage as compared to non-diabetic rats.

Memory improvement by modafinil at cost of metabolic hazards? A study to decipher the benefits and risks of modafinil in rats.

BACKGROUND: Modafinil is approved for narcolepsy and achieved high success in off-label indications in memory-related disorders. However, chronic indiscriminate use of modafinil imposes several health hazards like hyperglycaemia, obesity and metabolic syndrome, owing to impairment of sleep-wake cycle, circadian-rhythm, and neurotransmission. The present protocol elucidates the effects of modafinil per se and diabetic complications apropos. METHODS: Modafinil (100 and 200 mg/kg) was administered in rats from day 5-26. To induce type-2 diabetes, streptozotocin (STZ) was given on day 1, and blood glucose assessed on day 5. CPP (combination propranolol and phentolamine) was administered to antagonize sympathetic activity. After evaluation of cognitive functions, serum lipid profile, and biomarkers of oxidative stress and acetylcholinesterase (AChE) activity were assessed. RESULTS: Subacute dosing of modafinil significantly elevated blood glucose levels, albeit considerably less than diabetic group, and attenuated brain oxidative stress and AChE activity. Modafinil caused significant dyslipidaemia, increased body weight, whereas modestly altered abdominal circumference (AC) and thoracic circumference (TC) in rats. Significant hyperglycaemia, derangement of serum lipid-profile, brain lipid peroxidation, cholinergic hypofunction, and decrease in body weight and ACTC was noted in diabetic rats. Modafinil (100 mg/kg) significantly potentiated the hyperglycaemia and dyslipidaemia, however, attenuated oxidative stress and AChE activity in diabetic rats. Modafinil increased short-term (working) memory but not long-term spatial memory in normal and diabetic rats. CPP infusion attenuated these effects of modafinil. CONCLUSION: Subacute dosing of modafinil differentially modulates long-term and short-term memory subtypes, and also predisposes towards metabolic derangements.

Salivary molecular spectroscopy: A sustainable, rapid and non-invasive monitoring tool for diabetes mellitus during insulin treatment.

Monitoring of blood glucose is an invasive, painful and costly practice in diabetes. Consequently, the search for a more cost-effective (reagent-free), non-invasive and specific diabetes monitoring method is of great interest. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been used in diagnosis of several diseases, however, applications in the monitoring of diabetic treatment are just beginning to emerge. Here, we used ATR-FTIR spectroscopy to evaluate saliva of non-diabetic (ND), diabetic (D) and insulin-treated diabetic (D+I) rats to identify potential salivary biomarkers related to glucose monitoring. The spectrum of saliva of ND, D and D+I rats displayed several unique vibrational modes and from these, two vibrational modes were pre-validated as potential diagnostic biomarkers by ROC curve analysis with significant correlation with glycemia. Compared to the ND and D+I rats, classification of D rats was achieved with a sensitivity of 100%, and an average specificity of 93.33% and 100% using bands 1452 cm-1 and 836 cm-1, respectively. Moreover, 1452 cm-1 and 836 cm-1 spectral bands proved to be robust spectral biomarkers and highly correlated with glycemia (R2 of 0.801 and 0.788, P < 0.01, respectively). Both PCA-LDA and HCA classifications achieved an accuracy of 95.2%. Spectral salivary biomarkers discovered using univariate and multivariate analysis may provide a novel robust alternative for diabetes monitoring using a non-invasive and green technology.

Coadministration of Polypeptide-k and Curcumin Through Solid Self-Nanoemulsifying Drug Delivery System for Better Therapeutic Effect Against Diabetes Mellitus: Formulation, Optimization, Biopharmaceutical Characterization, and Pharmacodynamic Assessment.

An attempt has been made to prepare solid self-nanoemulsifying drug delivery system (SNEDDS) of polypeptide-k (PPK) and curcumin (CRM) using Labrafil M1944 CS as oil, Tween-80 as surfactant, Transcutol P as cosurfactant and Aerosil-200 (A-200) as porous hydrophobic carrier for improving their antidiabetic potential through oral delivery. Box-Behnken Design was used to optimize the liquid formulation based on the results of the mean droplet size, polydispersity index, percentage drug loading, and zeta potential. The formulation was adsorbed on Aerosil-200 through spray drying. The formulation showed desirable micromeritic, disintegration, and dissolution properties. About fivefold rise in the dissolution and permeation rate for drugs was observed from formulations vis a vis their unprocessed forms. The formulation was found to be stable with variation in pH, dilution, and temperature. The individual solid SNEDDS formulation of PPK and CRM and their combination were evaluated for antidiabetic potential and the results were compared with their naive forms on streptozotocin-induced diabetic rats. The results revealed better control of serum glucose level and other biochemical tests, such as liver parameters, lipid profiles, and antioxidant levels, as well as histological evaluation of pancreatic tissues in all the solid SNEDDS formulation as compared with their naive forms.

Amelioration of diabetic nephropathy using pomegranate peel extract-stabilized gold nanoparticles: assessment of NF-κB and Nrf2 signaling system.

BACKGROUND: Diabetic nephropathy (DN), an end-stage renal disorder, has posed a menace to humankind globally, because of its complex nature and poorly understandable intricate mechanism. In recent times, functional foods as potential health benefits have been gaining attention of consumers and researchers alike. Rich in antioxidants, the peel and seed of pomegranate have previously demonstrated protection against oxidative-stress-related diseases, including cardiovascular disorders, diabetes, and cancer. PURPOSE: This study was designed to investigate the ameliorative role of pomegranate peel extract-stabilized gold nanoparticle (PPE-AuNP) on streptozotocin (STZ)-induced DN in an experimental murine model. METHODS: Following the reduction methods, AuNP was prepared using the pomegranate peel ellagitannins and characterized by particle size, physical appearance, and morphological architecture. Modulatory potential of PPE-AuNP was examined through the plethora of biochemical and high throughput techniques, flow cytometry, immunoblotting, and immunofluorescence. RESULTS: The animals treated with PPE-AuNP markedly reduced the fasting blood glucose, renal toxicity indices, and serum TC and TG in a hyperglycemic condition. As evident from an increased level of plasma insulin level, PPE-AuNP normalized the STZ-induced pancreatic ß-cell dysfunction. The STZ-mediated suppression of endogenous antioxidant response was restored by the PPE-AuNP treatment, which reduced the generation of LPO as well as iROS. Furthermore, the hyperglycemia-mediated augmentation of protein glycation, followed by the NOX4/p-47phox activation, diminished with the application of PPE-AuNP. The histological and immunohistochemical findings showed the protective efficacy of PPE-AuNP in reducing STZ-induced glomerular sclerosis and renal fibrosis. In addition, it reduced proinflammatory burden through the modulation of the MAPK/NF-κB/STAT3/cytokine axis. Simultaneously, PI3K/AKT-guided Nrf2 activation was evident upon the PPE-AuNP application, which enhanced the antioxidant response and maintained hyperglycemic homeostasis. CONCLUSION: The findings indicate that the use of PPE-AuNPs might act as an economic therapeutic remedy for alleviating DN.

Novel hybrids of benzothiazole-1,3,4-oxadiazole-4-thiazolidinone: Synthesis, in silico ADME study, molecular docking and in vivo anti-diabetic assessment.

A series of new benzothiazole-1,3,4-oxadiazole-4-thiazolidinone hybrid analogs (Tz1-Tz28) were synthesized in search of potential anti-diabetic agents. Molecular docking study was conducted with binding pocket of peroxisome proliferator activated receptor-gamma to elucidate the binding interactions of newly synthesized targets. Seven selected compounds with best docking scores were further screened for in vivo anti-hyperglycemic efficacy by oral glucose tolerance test in non-diabetic rats and on streptozotocin induced diabetic rat models. All the tested compounds demonstrated excellent to moderate reduction in blood glucose levels. Three of the compounds (Tz21, Tz7 and Tz10) showed excellent anti-diabetic effect by reducing concentration of glucose to 157.15 ±â€¯1.79 mg/dL, 154.39 ±â€¯1.71 mg/dL, 167.36 ±â€¯2.45 mg/dL, respectively better than the standard drug, pioglitazone, 178.32 ±â€¯1.88 mg/dL. Moreover, three derivatives Tz21, Tz4 and Tz24 with IC50 values of 0.21 ±â€¯0.01 µM, 9.03 ±â€¯0.12 µM and 11.96 ±â€¯0.40 µM respectively also showed better inhibitory activities on alpha-glucosidase even more than the standard acarbose (IC50 = 18.5 ±â€¯0.20 µM), indicating Tz21 has the highest inhibitory effect among the seven tested derivatives. Prediction of Drug like properties using molinspiration online software suggests that all the synthesized compounds have potential of becoming the orally active molecules. Thus, these novel hybrids could serve as potential candidates to become leads for the development of new drugs eliciting anti-hyperglycemic effect orally.

Assessment of anti-diabetic activity of peanut shell polyphenol extracts.

The present study aimed to evaluate the anti-diabetic property of peanut shell polyphenol extracts (PSPEs). Diabetic rats were oral-administrated with PSPE at doses of 50, 100, and 200 mg/kg body weight (BW) per day for 28 consecutive days, with metformin (Met) as a positive control. The results showed that, similar to the Met treatment, administration of PSPE caused significant decreases in food intake, water intake, fasting blood glucose, total cholesterol, triglyceride, low-density lipoprotein cholesterol, and methane dicarboxylic aldehyde in serum, and significant increases in BW, insulin level, high-density lipoprotein cholesterol, superoxide dismutase, glutathione, and liver glycogen. Further, glucose tolerance was markedly improved in the PSPE-treated diabetic groups. Histopathological results showed that PSPE improved cellular structural and pathological changes in liver, kidney, and pancreatic islets. Collectively, the results indicated that the hypoglycemic effects of PSPE on high-fat diet/streptozotocin (HFD/STZ)-induced diabetes are comparable to Met, though their exact mechanism actions are still under investigation. Therefore, the current study suggests that PSPE could be a potential health-care food supplement in the management of diabetes.

Magnetoliposomes as Contrast Agents for Longitudinal in vivo Assessment of Transplanted Pancreatic Islets in a Diabetic Rat Model.

Magnetoliposomes (MLs) were synthesized and tested for longitudinal monitoring of transplanted pancreatic islets using magnetic resonance imaging (MRI) in rat models. The rat insulinoma cell line INS-1E and isolated pancreatic islets from outbred and inbred rats were used to optimize labeling conditions in vitro. Strong MRI contrast was generated by islets exposed to 50 µg Fe/ml for 24 hours without any increased cell death, loss of function or other signs of toxicity. In vivo experiments showed that pancreatic islets (50-1000 units) labeled with MLs were detectable for up to 6 weeks post-transplantation in the kidney subcapsular space. Islets were also monitored for two weeks following transplantation through the portal vein of the liver. Hereby, islets labeled with MLs and transplanted under the left kidney capsule were able to correct hyperglycemia and had stable MRI signals until nephrectomy. Interestingly, in vivo MRI of streptozotocin induced diabetic rats transplanted with allogeneic islets demonstrated loss of MRI contrast between 7-16 days, indicative of loss of islet structure. MLs used in this study were not only beneficial for monitoring the location of transplanted islets in vivo with high sensitivity but also reported on islet integrity and hereby indirectly on islet function and rejection.

Establishment and Assessment of Mice Models of Type 2 Diabetes Mellitus.

Objective To establish type 2 diabetes mellitus(T2DM)KM mouse models via the combined use of high-calorie diet and multiple administration of low-dose streptozotocin(STZ). Methods Based on the randomized number table,30 KM mice were equally and randomly divided into 2 groups:modeling group and control group. Mice in the modeling group were given foods with high calories for one month and injected with 30 mg/kg STZ via the left lower abdominal cavity for 2-4 consecutive days,while mice in the control group were fed with standard maintenance foods and the same dose of citrate buffer solution. The general conditions including food and water intake and mice weight were recorded. Blood glucose level was measured 1,2,4,5,12,and 21 weeks after STZ injection. When the glucose level became stabilized,the serum insulin and blood lipids [including total cholesterol(TC),triacylglycerol(TG),high-density lipoprotein(HDL) and low-density lipoprotein(LDL)],and hemoglobin a1c (HbA1c)were measured,and oral glucose tolerance test were performed. Results The modeling group had a 100% survival rate. After STZ injection,the body weight of mice in the modeling group reached the peak in the forth week,and later the growth rate decreased,still significantly lower than that of control group mice till the 21st week(t=3.160,P=0.006). Their blood glucose level was significantly higher than that of mice before STZ injection and in the control group(all P<0.05);as time went on,it was also rising,and it remained high till the 21st week [(26.38±1.34)mmol/L]. In the 4th week,the fasting blood glucose of mice in the modeling group was(11.86±3.33)mmol/L,which was significantly higher than that of mice in the control group [(6.37±1.27)mmol/L](t=-3.830,P=0.002). Fasting serum insulin of mice in the modeling group showed no significant difference compared with control group [(5.73±0.24)mU/L vs.(5.48±0.32)mU/L;t=-0.863,P=0.416]. Insulin sensitivity index was 0.0145±0.0039,which was significantly lower than that(0.0267±0.0039)in control group(t=4.414,P=0.003). In the 6th week,the blood glucose levels of mice in the modeling group were(15.35±1.82),(26.45±1.07),(25.58±1.46),and(26.15±1.00)mmol/L 0,30,60,and 120 min after oral gavage of D-glucose,which were all significantly higher than those in the control group [(6.88±1.75)(t=-8.203,P=0.000),(17.65±2.94)(t=-6.884,P=0.000),(13.18±2.04)(t=-12.110,P=0.000),and(7.37±3.40)mmol/L(t=-12.969,P=0.000)]. In the 8th week,serum TC and TG levels of mice in the modeling group were(3.83±0.06)and(2.20±0.20)mmol/L,which were significantly higher than those in the control group [(3.10±0.10)(t=11.000,P=0.000)and(0.90±0.10)mmol/L(t=10.070,P=0.000)]. HDL level of mice in the modeling group was(2.03±0.06)mmol/L,which was significantly lower than that in the control group [(2.48±0.02)mmol/L;t=11.662,P=0.000]. LDL level was increased but showed no significant difference [(0.34±0.08)mmol/L vs.(0.26±0.02)mmol/L](t=1.680,P=0.168). HbA1c content of mice in the modeling group was(7.30±0.31)%,which was significantly higher than that(4.40±0.32)% in the control group(t=-11.587,P=0.000). Conclusion KM mice models of T2DM were successfully established after high-calorie diet and multiple administration of low-dose STZ.

Assessment of the Anti-Hyperglycaemic, Anti-Inflammatory and Antioxidant Activities of the Methanol Extract of Moringa Oleifera in Diabetes-Induced Nephrotoxic Male Wistar Rats.

Diabetes mellitus is an endocrine disease of multiple aetiologies in insulin secretion. A deficiency in insulin results in hyperglycemia with metabolic disturbances of biomolecules. Moringa oleifera (MO) is endemic in the tropics with a variety of ethnomedicinal importance. The leaf of this plant has been reported to possess antioxidant and medicinal properties that may be helpful in the treatment and management of diabetes and its associated complications. Diabetes was induced intraperitoneally in rats by a single dose of streptozotocin (55 mg/kg) and treated with methanolic extract of Moringa oleifera (250 mg/kg b.wt) for six weeks. Forty-eight (48) adult male Wistar strain rats were randomly divided into four groups: normal control (NC), Moringa oleifera treated control rats (NC + MO), diabetic rats (DM) and Moringa oleifera treated diabetic rats (DM + MO). Estimation of antioxidant capacity, total polyphenols, flavonoids and flavonols content of Moringa oleifera extract was performed and serum biochemical markers were evaluated. Antioxidants such as catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) activities, glutathione (GSH) and inflammatory biomarkers were determined in the kidney. Results showed high antioxidant capacities of MO extract and improved serum biochemical markers, whilst lipid peroxidation (MDA) levels were reduced in non-diabetic and diabetic rats after MO treatment when compared to normal control. Subsequent administration of MO led to an increased concentration of serum albumin, globulin and total protein with a decrease in the level of MDA, and improvements in CAT, SOD, GSH, GPx, (tumour necrosis factor-alpha)TNF-α and (interleukin-6)IL-6. MO contains potent phytochemical constituents that offer protective action against diabetic-induced renal damage, reactive oxygen species (ROS) and inflammation and could therefore play a role in reducing diabetic complications, particularly in developing countries such as in Africa where the majority cannot afford orthodox medicine.

In vivo assessment of antidiabetic and antioxidative activity of natural phytochemical isolated from fruit-pulp of Eugenia jambolana in streptozotocin-induced diabetic rats.

OBJECTIVES: Eugenia jambolana (E. jambolana) is well known for its antidiabetic potential. The aim of the present study was to investigate the antidiabetic and antioxidative effect of an active compound (FIIc) isolated from fruit-pulp of E. jambolana in streptozotocin (45 mg/kg body weight)-induced diabetic rats. METHODS: FIIc was isolated from the crude aqueous extract of fruit-pulp by ion-exchange column chromatography and high-performance column chromatography. Detailed UV, NMR, and IR spectra suggested that FIIc is α-hydroxy succinamic acid. FIIc was orally administered to diabetic rats at a dose of 10, 15, and 20 mg/kg body weight (mg/kg bwt.) to determine its effective dose. Thereafter, effective dose was administered to 8 weeks to determine its antidiabetic and antioxidative activity by estimation of glycemic index, lipid profile, key enzymes of carbohydrate metabolism, and oxidative stress parameters. RESULTS: Administration of 15 mg/kg dose daily for 8 weeks led to significant (P < 0.001) fall in fasting blood glucose. Treatment with FIIc (15 mg/kg bwt.) showed significant improvement (P < 0.001) in all the biochemical parameters. DISCUSSION: The results demonstrate that FIIc possesses significant antidiabetic and antioxidative activity.