Effects of autophagy inhibitor 3-methyladenine on a diabetic mice model

AIM:To investigate the role of autophagy inhibitor 3-methyladenine(3-MA)on a diabetic mice model(DM)and the potential mechanism.METHODS:Male C57BL/6J mice were randomly divided into a normal control group(NC group)and an DM group.DM were induced by multiple low-dose intraperitoneal injection of streptozotocin(STZ)60 mg/kgd for 5 consecutive days.DM mice were randomly subdivided into untreated group(DM group),3-MA(10 mg/kgd by gavage)treated group(DM+3-MA group)and chloroquine(CQ;50 mg/kg by intraperitoneal injection)treated group(DM+CQ group).The fasting blood glucose(FBG)levels were recorded every week.At the end of experiment,retinal samples were collected.The expression levels of pro-apoptotic proteins cleaved caspase-3,cleaved poly ADP-ribose polymerase 1(PARP1)and Bax,anti-apoptotic protein Bcl-2,fibrosisassociated proteins Fibronectin and type 1 collagenα1 chain(COL1A1),vascular endothelial growth factor(VEGF),inflammatory factors interleukin(IL)-1βand tumor necrosis factor(TNF)-α,as well as autophagy related proteins LC3,Beclin-1 and P62 were determined by Western blotting.The oxidative stress indicators 8-hydroxydeoxyguanosine(8-OHdG)and malondialdehyde(MDA)were detected by commercial kits.RESULTS:Both 3-MA and CQ had shor t-term hypoglycemic effect on FBG and reduced the expression of VEGF and inflammatory factors IL-1βand TNF-αin DM mice.3-MA also significantly alleviated oxidative stress indicators 8-OHdG and MDA,decreased the expression of fibrosisrelated proteins Fibronectin and COL1A1,pro-apoptotic proteins cleaved caspase-3,cleaved PARP1,as well as the ratio of Bax/Bcl-2.CQ had no significant impact on the oxidative stress indicators,fibrosis,and apoptosis related proteins.The results of Western blotting for autophagy related proteins showed that the ratio of LC3 II/LC3 I and the expression of Beclin-1 in the retina of DM mice were decreased by 3-MA treatment,and the expression of P62 was further increased by CQ treatment.CONCLUSION:3-MA has anti-apoptotic and anti-fibrotic effects on the retina of DM mice,and can attenuate retinal oxidative stress,VEGF expression and the production of inflammatory factors in the retina of DM mice.The underlying mechanism of the above effects of 3-MA may be related to its inhibition of early autophagy and hypoglycemic effect.

Effect of methanolic extract of Tetrapleura tetraptera(Schum and Thonn)Taub leaves on hyperglycemia and indices of diabetic complications in alloxan-induced diabetic rats

Objective:To investigate the ameliorative role of Tetrapleura tetraplera(Schum and Thonn)Taub(T.tetraplera)leaf in hyperglycemia with associated conditions like oxidative stress,kidney damage and disorders in lipid metabolism.Methods:Five groups of five rats each intraperitoneally received the following treatment schedules for 7 d:untreated normal control,untreated alloxan-diabetic control,diabetic treated with glibenclamide,normal rats treated with extract(50 mg/kg)and diabetic rats treated with the extract.Evaluations were made for fasting blood sugar,body weight changes,malondialdehyde,aspartate aminotransferase,alanine aminotransferase,bilirubin,superoxide dismutase,catalase,lipid profile,packed cell volume,hemoglobin,urea and creatinine in all the rats.Results:Whereas the untreated diabetic rats showed a significant decrease(P<0.05)in packed cell volume,superoxide dismutase,catalase and high-density lipoprotein-cholesterol with a concomitant increase in the levels of malondialdehyde,fasting blood sugar,aspartate aminotransferase,alanine aminotransferase,bilirubin,urea and creatinine,administration of methanolic extract of T.tetraplera leaf or glibenclamide alleviated these altered parameters in the treated rats.Conclusions:Methanolic extract of T.tetraplera leaves possesses a potent capacity for treatment of diabetes and the accompanying complications,including oxidative stress and hyperlipidemia.

Triptolide prolonged allogeneic islet graft survival in chemically induced and spontaneously diabetic mice without impairment of islet function

BACKGROUND: Triptolide (TPT) is a diterpenoid triepoxide extracted from the Chinese herb Tripterygium wilfordii Hook. F. It exhibits potent immunosuppressive and anti-inflammatory properties. This study was undertaken to investigate its effects on prolongation of islet allograft survival in rodents. Additionally, we investigated whether TPT would be toxic to islet function in vivo. METHODS: We transplanted BALB/c islets to either chemically induced diabetic C57BL/6 mice or spontaneously diabetic non-obese diabetic (NOD) mice. TPT was injected within 2 weeks or continuously, until rejection, in the two combinations. Then, we evaluated the toxicity of TPT on islet function by daily injection to naive BALB/c or diabetic BALB/c that was cured by syngeneic islet transplantation under the kidney capsule. Mice injected with cyclosporine A (CsA) or vehicle served as controls. Intraperitoneal glucose tolerance tests (IPGTTs) performed at 4 and 8 weeks in the naive BALB/c group, and at 2, 4, 6, and 8 weeks in the syngeneic transplanted group. RESULTS: The medium survival time of islets allograft from TPT treated C57BL/6 and NOD recipients were 28.5 days (range 24-30 days, n=10) and 33.0 days (range 15-47 days, n=6), respectively, and they were significantly different from those of the vehicle treated controls, which were 14.0 days (range 13-16 days, n=6) and 5.0 days (range 4-10 days, n=6), respectively (all P<0.0001). The IPGTT demonstrated that there was no difference between the TPT treated and vehicle treated groups, either in the normal or syngeneic transplanted islet BALB/c mice. However, CsA injection impaired islet function in both normal and syngeneic transplanted mice as early as 4 weeks. CONCLUSION: TPT prolonged islets allograft survival in a chemically induced diabetic or an autoimmune diabetic murine model without impairment of islet function. (Hepatobiliary Pancreat Dis Int 2010; 9: 312-318)

Aralia elata inhibits neurodegeneration by downregulating O-GlcNAcylation of NF-κB in diabetic mice

AIM： To investigate the role of O-GIcNAcylation of nuclear factor-kappa B （NF-KB） in retinal ganglion cell （RGC） death and analysedthe effect of Aralia elata （AE） on neurodegen- eration in diabetic mice. METHODS： C57BL/6mice with streptozotocin-induced diabetes were fed daily with AE extract or control （CTL） diet at the onset of diabetes mellitus （DM）. Two months af- tar injection of streptozotocin or saline, the degree of cell death and the expression of O-GIcNAc transferase （OGT）, N-acetyl-b-D-glucosaminidase （OGA）, O-GIcNAcylated pro- teins, and O-GIcNAcylation of NF-KB were examined. RESULTS： AE did not affect the metabolic status of diabetic mice. The decrease in the inner retinal thickness （P〈0.001 vs CTL, P〈0.01 vs DM） and increases in RGCs with terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling （P〈0.001 vs CTL, P〈0.0001 vs DM）, glial activation, and active caspase-3 （P〈0.0001 vs CTL, P〈0.0001 vs DM） were blocked in diabetic retinas of AE extract-fed mice. Expression levels of protein O-GIcNAcylation and OGT were increased in diabetic retinas （P〈0.0001 vs CTL）, and the level of O-GIcNAcylation of the NF-KB p65 subunit was higher in diabetic retinas than in controls （P〈0.0001 vs CTL）. AE extract downregulated O-GIcNAcylation of NF-KB and prevented neurodegeneration induced by hyperglycemia （P〈0.0001 vs DM）. CONCLUSION： O-GIcNAcylation of NF-KB is concerned in neuronal degeneration and that AE prevents diabetes-in- duced RGC apoptosis via downregulation of NF-KB O-GI- cNAcylation. Hence, O-GIcNAcylation may be a new object for the treatment of DR, and AE may have therapeutic pos- sibility to prevent diabetes-induced neurodegeneration.

Phenylethanoid glycosides from traditional Mongolian medicine Cymbaria daurica alleviate alloxan-induced INS-1 cells oxidative stress and apoptosis

Cymbaria daurica L. is a well-known traditional Mongolian medicine, which has been used to treat diabetesrelated conditions characterized by persistent thirst and hunger, copious urination, and weight loss. We aimed to investigate the protective effects of C. daurica extracts and phenylethanoid glycosides including verbascoside and isoacteoside on INS-1 cells. We discovered phenylethanoid glycosides from n-butanol extract with large content through extraction and separation. We continue to study the protective effects of phenylethanoid glycosides including verbascoside and isoacteoside on INS-1 cells. INS-1 cells were treated with C. daurica, cell viability assay, RNA-seq technology, superoxide dismutase activity and malonaldehyde content, quantitative real time-PCR and Western blot analysis were used to study the protective effects of C. daurica. Cell viability assay resulted that n-butanol extract and verbascoside, isoacteoside showed protective effects of C. daurica. According to the RNA-seq technology to identify the differentially expressed genes in INS-1 cells, the pathway of gene enrich the protective effect of C. daurica on oxidative stress. SOD activity and the content of MDA indicated that C. daurica could enhance the antioxidant capacity of INS-1 cells. Further investigation indicated C. daurica alleviate oxidative stress by inhibiting INS-1 cell apoptosis. C. daurica may play an anti-diabetic role by inhibiting islet cell apoptosis.

Diabetes exacerbates inflammatory bowel disease in mice with dietinduced obesity

BACKGROUND The increased prevalence of inflammatory bowel disease(IBD)among patients with obesity and type 2 diabetes suggests a causal link between these diseases,potentially involving the effect of hyperglycemia to disrupt intestinal barrier integrity.AIM To investigate whether the deleterious impact of diabetes on the intestinal barrier is associated with increased IBD severity in a murine model of colitis in mice with and without diet-induced obesity.METHODS Mice were fed chow or a high-fat diet and subsequently received streptozotocin to induce diabetic-range hyperglycemia.Six weeks later,dextran sodium sulfate was given to induce colitis.In select experiments,a subset of diabetic mice was treated with the antidiabetic drug dapagliflozin prior to colitis onset.Endpoints included both clinical and histological measures of colitis activity as well as histochemical markers of colonic epithelial barrier integrity.RESULTS In mice given a high-fat diet,but not chow-fed animals,diabetes was associated with significantly increased clinical colitis activity and histopathologic markers of disease severity.Diabetes was also associated with a decrease in key components that regulate colonic epithelial barrier integrity(colonic mucin layer content and epithelial tight junction proteins)in diet-induced obese mice.Each of these effects of diabetes in diet-induced obese mice was ameliorated by restoring normoglycemia.CONCLUSION In obese mice,diabetes worsened clinical and pathologic outcomes of colitis via mechanisms that are reversible with treatment of hyperglycemia.Hyperglycemia-induced intestinal barrier dysfunction offers a plausible mechanism linking diabetes to increased colitis severity.These findings suggest that effective diabetes management may decrease the clinical severity of IBD.

PDE5 inhibitors promote recovery of peripheral neuropathy in diabetic mice

Diabetes mellitus affects an estimated 422 million people worldwide.Peripheral neuropathy is one of the most common and disabling complications of diabetes.There is currently no effective treatment for diabetic neuropathy,

Expression and role of P-element-induced wimpy testis-interacting RNA in diabetic-retinopathy in mice

BACKGROUND As one of the major microvascular complications of diabetes,diabetic retinopathy(DR)is the leading cause of blindness in the working age population.Because the extremely complex pathogenesis of DR has not been fully clarified,the occurrence and development of DR is closely related to tissue ischemia and hypoxia and neovascularization The formation of retinal neovascularization(RNV)has great harm to the visual acuity of patients.AIM To investigate the expression of P-element-induced wimpy testis-interacting RNA(piRNA)in proliferative DR mice and select piRNA related to RNV.METHODS One hundred healthy C57BL/6J mice were randomly divided into a normal group as control group(CG)and proliferative DR(PDR)group as experimental group(EG),with 50 mice in each group.Samples were collected from both groups at the same time,and the lesions of mice were evaluated by hematoxylin and eosin staining and retinal blood vessel staining.The retinal tissues were collected for second-generation high-throughput sequencing,and the differentially expressed piRNA between the CG and EG was detected,and polymerase chain reaction(PCR)was conducted for verification.The differentially obtained piRNA target genes and expression profiles were enrichment analysis based on gene annotation(Gene Ontology)and Kyoto Encyclopedia of Genes and Genomes.RESULTS In the CG there was no perfusion area,neovascularization and endothelial nucleus broke through the inner boundary membrane of retinap.In the EG,there were a lot of nonperfused areas,new blood vessels and endothelial nuclei breaking through the inner boundary membrane of the retina.There was a statistically significant difference in the number of vascular endothelial nuclei breaking through the inner retinal membrane between the two groups.High-throughput sequencing analysis showed that compared with the CG,a total of 79 piRNAs were differentially expressed in EG,among which 43 piRNAs were up-regulated and 36 piRNAs were down-regulated.Bioinformatics analysis showed that the differentially expressed piRNAs were mainly concentrated in the signaling pathways of angiogenesis and cell proliferation.Ten piRNAs were selected for PCR,and the results showed that the expression of piR-MMU-40373735,piRMMU-61121420,piR-MMU-55687822,piR-MMU-1373887 were high,and the expression of piR-MMU-7401535,piR-MMU-4773779,piR-MMU-1304999,and piR-MMU-5160126 were low,which were consistent with the sequencing results.CONCLUSION In the EG,the abnormal expression of piRNA is involved in the pathway of angiogenesis and cell proliferation,suggesting that piRNAs have some regulatory function in proliferative diabetic-retinopathy.

Verification of Lactobacillus brevis tolerance to simulated gastric juice and the potential effects of postbiotic gamma-aminobutyric acid in streptozotocin-induced diabetic mice

The therapeutic effect of gamma-aminobutyric acid(GABA)on diabetes was spread as one of the alarming epidemics worldwide.The study aims to investigate the function of Lactobacillus brevis KLDS_(1.0727) and KLDS_(1.0373) strains as glutamic acid decarboxylase 65(GAD65)carriers capable of generating GABA by comparing in vitro free and freeze-dried models and GABA intervention in vivo.PCR amplification of gad and in vitro i.e.,(growth rate,viability at different pH,bile tolerance,and survivability in simulated gastric juice)were performed.In vivo experiments were conducted in 7 groups of C57BL/6J mice.Each group was injected with streptozotocin(Cont_(STZ),INSSTZ,LAC1_(STZ),LAC_(1MFDSTZ),LAC_(2STZ),LAC_(2MFDSTZ))daily except for the control(Cont).One group was injected with insulin(INSSTZ).The body weight and hyperglycemia in the blood were assessed weekly,post-euthanasia blood plasma parameters,insulin,and histological examination were evaluated.Results indicated L.brevis strains demonstrated a great tolerance to bile and simulated gastric juice in vitro(P<0.05).Cont_(STZ) had the highest average glucose level(6.84±6.46)mmol/L while INS_(STZ) expressed dramatically decreed in glucose level and displayed a significant decline in the average of weekly blood glucose(−5.74±3.08)mmol/L.The lowest body weight(ContSTZ)was(19.30±0.25)g.Based on the blood plasma analysis,L.brevis strains improved good cholesterol properties,liver and kidney functions,where most of these parameters fall within the average the reference range and prevent the development of symptoms of type 1 diabetes in vivo.As recommended,L.brevis should be commonly distributed as a postbiotic GABA in pharmaceutical and nutritional applications.

Gastric motor effects of ghrelin and growth hormone releasing peptide 6 in diabetic mice with gastroparesis

AIM:To investigate the potential therapeutic significance of ghrelin and growth hormone releasing peptide 6 (GHRP-6) in diabetic mice with gastric motility disorders. METHODS: A diabetic mouse model was established by intraperitoneal (ip) injection of alloxan. Diabetic mice were injected ip with ghrelin or GHRP-6 (20-200 μg/kg), and the effects on gastric emptying were measured after intragastric application of phenol red. The effect of atropine, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) or D-Lys3-GHRP-6 (a growth hormone secretagogue receptor (GHS-R) antagonist) on the gastroprokinetic effect of ghrelin or GHRP-6 (100 μg/kg) was also investigated. The effects of ghrelin or GHRP-6 (0.01-10 μmol/L) on spontaneous or carbachol-induced contractile amplitude were also investigated in vitro, in gastric fundic circular strips taken from diabetic mice. The presence of growth hormone secretagogue receptor 1a transcripts in the fundic strips of diabetic mice was detected by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: We established a diabetic mouse model with delayed gastric emptying. Ghrelin and GHRP-6 accelerated gastric emptying in diabetic mice with gastroparesis. In the presence of atropine or L-NAME, which delayed gastric emptying, ghrelin and GHRP-6 (100 μg/kg) failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying induced by the GHS-R agonist. Ghrelin and GHRP-6 increased the carbachol-induced contractile amplitude in gastric fundicstrips taken from diabetic mice. RT-PCR confirmed the presence of GHS-R mRNA in the strip preparations. CONCLUSION: Ghrelin and GHRP-6 increase gastric emptying in diabetic mice with gastroparesis, perhaps by activating peripheral cholinergic pathways in the enteric nervous system.

Effects of Bofutsushosan and Gardeniae Fructus on Diabetic Serum Parameters in Streptozotocin-Induced Diabetic Mice

Streptozotocin (STZ)-induced diabetic mice increased levels of serum glucose, triglyceride and cholesterol, and decreased level of serum insulin. Effects of Bofutsushosan (BOF: Pulvis ledebouriellae compositae: 防風通聖散) and its composed crude drug, gardeniae fructus (GF: 山梔子) were investigated on levels of these diabetic parameters (serum glucose, insulin, triglyceride and cholesterol) in STZ-diabetic mice. BOF and GF were extracted in 10 volumes of distilled water with an automatic extractor “Torobi”. STZ-induced diabetic mice with serum glucose level of over 600 mg/dl at 3 - 4 weeks after intravenous injection of 150 mg/kg STZ were used for experiments. BOF extract, GF extract, geniposide (a main constituent of GF), and glibenclamide were administered intraperitoneally into 3-hour-fasted STZ-diabetic mice. At 6 hours after administration, BOF extract (100 - 300 mg/kg) decreased high levels of serum glucose, triglyceride and cholesterol, and also increased low level of serum insulin in STZ-diabetic mice in a dose-dependent manner, respectively. Anti-diabetic drug glibenclamide (0.3 - 1 mg/kg) as positive control significantly decreased serum glucose and cholesterol levels, and increased serum insulin level in the diabetic mice. GF extract (30 - 300 mg/kg) decreased serum glucose, triglyceride and cholesterol levels but did not affect serum insulin level in the diabetic mice. Geniposide (10 - 100 mg/kg), decreased serum glucose level but did not affect serum insulin and triglyceride levels in the diabetic mice. These results demonstrated that intraperitoneally administrated BOF extract improved abnormal levels of serum glucose, insulin, triglyceride and cholesterol in the STZ-diabetic mice as being similar to glibenclamide. GF extract has an important role in a part of improving actions of BOF in the diabetic mice. The action of GF extract on serum glucose was parallel with the action of geniposide in the diabetic mice, supporting roles of geniposide in anti-hyperglycemic action of GF.

Pluronic L-81 ameliorates diabetic symptoms in db/db mice through transcriptional regulation of microsomal triglyceride transfer protein

AIM: To test whether oral L-81 treatment could im-prove the condition of mice with diabetes and to investigate how L-81 regulates microsomal triglyceride transfer protein (MTP) activity in the liver. METHODS: Genetically diabetic (db/db) mice were fed on chow supplemented with or without L-81 for 4 wk. The body weight, plasma glucose level, plasma lipid profile, and adipocyte volume of the db/db mice were assessed after treatment. Toxicity of L-81 was also evaluated. To understand the molecular mecha-nism, HepG2 cells were treated with L-81 and the effects on apolipoprotein B (apoB) secretion and mRNA level of the MTP gene were assessed.RESULTS: Treatment of db/db mice with L-81 sig-nificantly reduced and nearly normalized their body weight, hyperphagia and polydipsia. L-81 also markedly decreased the fasting plasma glucose level, improved glucose tolerance, and attenuated the elevated levels of plasma cholesterol and triglyceride. At the effective dosage, little toxicity was observed. Treatment of HepG2 cells with L-81 not only inhibited apoB secretion, but also signif icantly decreased the mRNA level of the MTP gene. Similar to the action of insulin, L-81 exerted its effect on the MTP promoter. CONCLUSION: L-81 represents a promising candidate in the development of a selective insulin-mimetic mol-ecule and an anti-diabetic agent.

A new look at cardiac pathophysiology difference in type 2 diabetic mice by comparative analysis

Objective To clarify the differences in cardiac structure,cardiac function,and myocardial metabolism in type 2 diabetes mellitus mice with obesity or non-obesity and to elucidate the key molecular mechanisms leading to this difference.Methods Db/db mice and low-dose STZ injection combined with HFD-induced diabetes mellitus mice were used in this study as the model of type 2 diabetes mellitus with obesity or non-obesity.

Antihyperglycemic effect of Passiflora glandulosa cav. fruit rinds flour in streptozotocin-induced diabetic mice

Objective:To investigate the effect of administration of Passiflora glandulosa(P.glandulosa) fruit rinds flour on streptozotocin(STZ)-induced diabetic mice.Methods:The preliminary phytochemical screening and parameters such as centesimal composition and brine shrimp toxicity were evaluated.For in vivo study Swiss female mice were divided into four groups:NC-normal control;DC-diabetic control animals receiving saline;MET-diabetic animals receiving metformin(200 mg/kg);PFRF-diabetic animals receiving P.glandulosa fruit rinds flour(200 mg/kg).All of them were treated for 28 d.STZ was used in a single dose of 120 mg/kg to establish diabetic models.Body weight,water and food intake,fasting blood glucose were measured.Histopathological analysis of pancreas and liver were performed to evaluate STZ-induced tissue injuries.Results:Phytochemical screening showed the presence of flavanones and triterpenoids.The P.glandulosa fruit rinds flour was non-toxic by the brine shrimp test.The fruit rinds flour also reduced the loss of body weight and significantly decreased food intake in the diabetic mice.Additionally,a significant reduction in blood glucose was observed for 15 d and this was maintained on 21 d and 28 d when compared with diabetic mice.Furthermore,the P.glandulosa fruit rinds flour has a favourable effect on the histopathological changes of the pancreas in STZ induced diabetes.Conclusions:It is concluded that P.glandulosa fruit rinds flour is a natural product that contains potent antioxidant compounds and presents good prospects for the improvement of diabetic mellitus by reducing serum glucose levels.

Amelioration of type 1 diabetes following treatment of non-obese diabetic mice with INGAP and lisofylline

Type 1 diabetes mellitus results from the autoimmune and inflammatory destruction of insulin-producing islet β cells, rendering individuals devoid of insulin production. Recent studies suggest that combination therapies consisting of anti-inflammatory agents and islet growth-promoting factors have the potential to cause sustained recovery of β cell mass, leading to amelioration or reversal of type 1 diabetes in mouse models. In this study, we hypothesized that the combination of the anti-inflammatory agent lisofylline (LSF) with an active peptide fragment of islet neogenesis associated protein (INGAP peptide) would lead to remission of type 1 diabetes in the non-obese diabetic (NOD) mouse. We treated groups of spontaneously diabetic NOD mice with combinations of LSF, INGAP peptide, or control saline parenterally for up to 6 weeks. Our results demonstrate that the mice receiving combined treatment with LSF and INGAP peptide exhibited partial remission of diabetes with increased plasma insulin levels. Histologic assessment of pancreata in mice receiving combined therapy revealed the presence of islet insulin staining, increased β cell replication, and evidence of Pdx1-positivity in ductal cells. By contrast, diabetic animals showed severe insulitis with no detectible insulin or Pdx1 staining. We conclude that the novel combination treatment with LSF and INGAP peptide has the potential to ameliorate hyperglycemia in the setting of established type 1 diabetes via the recovery of endogenous β cells and warrant further studies.

The Effect of High Carbohydrate Consumption on Glucose Levels and Antibody Production in Nonobese Diabetic Mice

The aim of this study was to evaluate the effect of chronic treatment with diets rich in carbohydrates on the IgM and IgG antibody production and the seric glucose concentration in diabetes. Nonobese diabetic (NOD) mice received, ad libitum, by oral route, the diet consisting of an aqueous extract (20 mg/mL) of the following flours: babassu mesocarp, manioc, corn or rice, during 120 days. The diet intake was monitored throughout this period. At the end, the weight variation, blood glucose, serum IgG and IgM antibody and IgM anti-insulin titers, were determined. The babassu and manioc flour extracts altered Purina chow intake and these animals also presented a significant increase in body weight. In contrast, treatment with rice flour resulted in a significant weight loss. Moderate to severe hyperglycemia was observed in the groups receiving rice and manioc, whereas treatment with babassu mesocarp flour and cornmeal resulted in hypoglycemia. The extracts did not alter the IgG concentration. On the other hand, the cornmeal extract caused a marked reduction in both total IgM and anti-insulin IgM antibody production. Although babassu mesocarp flour, cornmeal and manioc flour caused important variations in the parameters studied, only treatment with the rice flour extract anticipated the onset of diabetes in male mice genetically predisposed to the disease.

Formulation Development and <i>In-Vivo</i>Evaluation of Atorvastatin Calcium Solid Dispersion in Streptozotocin Induced Diabetic Mice

Atorvastatin calcium (ATV) is a selective competitive inhibitor of HMG CoA reductase characterized by poor aqueous solubility leading to inadequate bioavailability. The present study was designed to develop solid dispersion of atorvastatin (SDA) to improve the solubility and dissolution properties of ATV and evaluation of its in-vivo efficiency in streptozotocin (STZ) induced diabetic mice. Formulations of SDA were prepared by solvent evaporation method using PEG-4000 alone and/or mixture of PEG-4000 and Carplex-80 as carrier in different ratios. Solid-state analyses of SDA were performed to characterize the physicochemical properties of newly developed SDA by differential scanning calorimetry (DSC), powder x-ray diffractometry (PXRD), fourier transformed infrared spectra (FTIR) and scanning electron microscopy (SEM). DSC and PXRD showed that the crystallinity of drugs was notably decreased during the preparation of SDA. FTIR and SEM also demonstrated the conversion of ATV from amorphous to crystalline state resulting in improved solubility. Among formulations, SDA-5 showed significant enhancement of in-vitro drug release (around 2 fold higher) as compared to pure ATV. Further, in-vivo study was conducted to evaluate the effects of a newly developed ATV loaded solid dispersion on glycemic control, lipid profile, liver enzyme and histopathology in STZ induced diabetic mice. Oral administration of SDA significantly lowered the blood glucose levels during the course of treatment. Treatment with SDA significantly improved lipid profiles better than ATV alone and the effect was dose-dependent. After one week of SDA treatment significantly decreased liver weights as result of lipid clearance and the hepatocytes regained their normal architecture, and these beneficial effects can be correlated with the reduction of SGPT levels. The results demonstrated that, SDA exerted better glycemic control, lipid lowering effect and organ protection (liver and pancreas) than that of conventional ATV in STZ induced diabetic mice. The mechanism by which SDA conferred better improvement in diabetic conditions can be partially explained by enhancement of solubility and dissolution rate when ATV is loaded in solid dispersion.

Effects of the fenugreek extracts on high-fat diet-fed and streptozotocin-induced type 2 diabetic mice

Background: To study the antidiabetic effects and mechanisms of the fenugreek extracts in streptozotocin(STZ)-induced type 2 diabetic(T2 DM) mice fed a high-fat diet(HFD).Methods: We established C57 BL/6 J mice model of T2 DM using HFD-fed and STZinduced method. Then, the mice were administered with two types of fenugreek extracts(E1, flavonoid and E2, stilbene glycoside) for 4 weeks and the effects on fasting blood glucose(FBG), weight, superoxide dismutase(SOD), catalase(CAT),malondialdehyde(MDA), and pathological indexes were investigated.Results: Administration of fenugreek extracts decreased the FBG level compared with that of the model group. Comparatively, the high-dose E2 decreased the FBG more significantly than the other treatments did. Both extracts showed an obvious antioxidant effect by increasing serum SOD and CAT activities and decreasing the MDA content. Furthermore, the high-dose E1 showed a significant difference(P <.01) compared with the model group in the three investigated indexes.Conclusion: Our study demonstrated that both the flavonoid and stilbene glycoside extracts of fenugreek improved the hyperglycemia in the T2 DM mice model. Moreover, the antidiabetic effects of both extracts might be due to their antioxidant activity in vivo.

In <i>Vivo</i>Hypoglycemic Activity of Aqueous Extracts of <i>Chasmanthera dependens</i>in Alloxan Induced Diabetic Mice

The plant Chasmanthera dependens (Hochst) have been used to manage many diseases including diabetes mellitus without scientific evaluation of its efficacy and safety. The main objective of the project was to determine the antidiabetic activity of Chasmanthera dependens plant in a rat model. Experimental design was used where the stem of the plant was collected, dried, crashed into fine powder, extracted with distilled water at 60°C and lyophilized using a Freeze Dryer, packaged in air tight container and stored at -20°C ready for use. The extract was orally and intraperitoneally screened in alloxan induced diabetic mice for its hypoglycemic activity at doses of 25, 48.4, 93.5, 180.9 and 350 mg per kg body weight. Diabetes in mice was induced using 186.9 mg/kg of alloxan monohydrate. Negative controls included normal and diabetic rats orally and intraperitoneally administered with physiological saline while positive controls included diabetic rats administered with glibenclamide as oral and insulin as intraperitoneal reference drug. The results revealed hypoglycemic activity in Chasmanthera dependens at the five different doses when given either orally or intraperitoneally. In conclusion, the medicinal plant at the various doses demonstrated significant (ρ ≤ 0.05) hypoglycemic activity. The author’s recommendation is continued use of the plant extracts at low therapeutic doses. Consideration should be made to carry out the same studies using higher animals including man.

Transfusion of CXCR4-priming endothelial progenitor cells reduces cerebral ischemic damage and promotes angiogenesis and neurogenesis in db/db diabetic mice

Previous studies suggest that reduction and dysfunction of circulating endothelial progenitor cells(EPCs),and dysregulation in stromal cell derived factor-1/CXC-chemokine receptor 4(SDF-1/ CXCR4) axis in diabetes could be therapeutic targets for diabetic ischemic stroke.This study investigated the efficacy of CXCR4-priming EPCs on cerebral repair following ischemic stroke in db/db diabetic mice.Bone marrow derived EPCs from db/+ control mice were transfected with adenovirus(1×10~7 IU) carrying CXCR4(Ad-CXCR4-EPCs)or null(Ad- null-EPCs).The db/db mice were divided into three groups for EPCs injection(2×10~5 cells/100μl): Ad-CXCR4-EPCs,Ad-null-EPCs or saline(vehicle), via tail vein 2 hrs after middle cerebral artery occlusion (MCAO) surgery.Cerebral blood flow(CBF) was measured with laser Doppler flowmeter.Mice were sacrificed at 2 or 7 days thereafter.Level of circulating EPCs was measured by flow cytometry. Ischemic damage,cerebral microvascular density (MVD),angiogenesis and neurogenesis were determined by histological staining with Fluoro-J,CD31, CD31 +BrdU,NeuN +BrdU,GFAP+BrdU,respectively. Results(table) showed:1) Levels of CXCR4 expression were reduced in the brain and EPCs of db/db mice as measured by real-time RT-PCR and western blot analyses(data not shown);2) The level of circulating EPCs was more in the mice treated with Ad-CXCR4-EPCs;3)EPC transfusion improved CBF,increased MVD,angiogenesis and neurogenesis in peri-infarct area,and decreased ischemic damage.The efficacies were better in Ad-CXCR4 -EPCs group.Data suggest that transfusion of Ad-CXCR4-EPCs could be a therapeutic avenue for ischemia stroke in diabetes.