OBJECTIVETo explore the effect of Jiangtang Xiaozhi capsule (JXC) on morphological changes of islets and liver at rat model of type 2 diabetic mellitus and provide the experimental basis for the clinical therapy of type 2 diabetic mellitus.

METHODWister rats were fed on a diet enriched in fat and glucose to induce insulin resistan, the rats were injected intrapertoneally with a low-dose streptozotocin (STZ) twice (25 mg x kg(-1)) to induce hyperglycemia, so the successful rat model of type 2 diabetes were established. The experimental rats were divided into model group, high dose JXC group, middle dose JXC group, low dose JXC group, Erjiashuanggua group, Jinqijiangtang group and normal control group. After all the treatment groups received their own medicine for two months, all the rats were sacrificed and morphological examination on their islets and livers were performed.

RESULTFatty liver in various degrees was seen in the model group and all the treatment groups, but the liver steatosis in middle and low dose JXC groups was significantly milder than that in model group (P < 0.05). Islets in the high dose JXC group were significantly more than that in the model group (P < 0.05).

CONCLUSIONJXC can improve significantly the pathological change in islets and liver steatosis at rat model of type 2 diabetic mellitus.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; pathology ; Drugs, Chinese Herbal ; pharmacology ; Female ; Islets of Langerhans ; drug effects ; pathology ; Liver ; drug effects ; pathology ; Male ; Microscopy ; Rats ; Rats, Wistar

OBJECTIVETo study the effects of a self-formulated blood glucose-adjusting recipe on blood glucose and pathology of the pancreas in diabetic mice.

METHODSDiabetes mellitus (DM) was induced in mice by injection of alloxan through the caudal vein. The blood glucose-adjusting recipe was administered in the mice at the doses of 20, 10 and 5 g/kg for 21 days, after which blood glucose was determined and the sugar tolerance was evaluated, and the pancreas and islet pathologies were examined microscopically.

RESULTSThe blood glucose-adjusting recipe at 20 g/kg significantly lowered the fast blood glucose in the mice, and at 20 and 10 g/kg, the recipe significantly lowered the blood glucose 2 h after glucose administration and increased the sugar tolerance. The pathological damage in the diabetic mice was alleviated after treatment with the recipe.

CONCLUSIONSThe blood glucose-adjusting recipe has a good effect in stabilizing blood glucose in mice.

Animals ; Blood Glucose ; drug effects ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; pathology ; Drugs, Chinese Herbal ; therapeutic use ; Islets of Langerhans ; pathology ; Mice ; Phytotherapy

Nonspecific inflammatory response is the major cause for failure of islet grafts at the early phase of intraportal islet transplantation (IPIT). Bilirubin, a natural product of heme catabolism, has displayed anti-oxidative and anti-inflammatory activities. The present study has demonstrated that bilirubin protected islet grafts by inhibiting nonspecific inflammatory response in a syngeneic rat model of IPIT. The inflammation-induced cell injury was mimicked by exposing cultured rat insulinoma INS-1 cells to cytokines (IL-1beta, TNF-alpha and IFN-gamma) in in vitro assays. At appropriate lower concentrations, bilirubin significantly attenuated the reduced cell viability and enhanced cell apoptosis induced by cytokines, and protected the insulin secretory function of INS-1 cells. Diabetic inbred male Lewis rats induced by streptozotocin underwent IPIT at different islet equivalents (IEQs) (optimal dose of 1000, and suboptimal doses of 750 or 500), and bilirubin was administered to the recipients every 12 h, starting from one day before transplantation until 5 days after transplantation. Administration of bilirubin improved glucose control and enhanced glucose tolerance in diabetic recipients, and reduced the serum levels of inflammatory mediators including IL-1beta, TNF-alpha, soluble intercellular adhesion molecule 1, monocyte chemoattractant protein-1 and NO, and inhibited the infiltration of Kupffer cells into the islet grafts, and restored insulin-producing ability of transplanted islets.
Animals ; Apoptosis/drug effects/immunology ; Bilirubin/*administration & dosage/pharmacology ; Cell Line, Tumor ; Cytokines/immunology/metabolism ; Diabetes Mellitus, Experimental/*drug therapy/*immunology ; Inflammation ; Inflammation Mediators/immunology/metabolism ; Islets of Langerhans/drug effects/*immunology/injuries/pathology ; *Islets of Langerhans Transplantation ; Male ; Oxidative Stress/drug effects/immunology ; Rats ; Rats, Inbred Lew ; Transplantation, I

Pancreatic islet transplantation can correct the abnormal glucose metabolism of Type 1 diabetes. Although immunosuppressants greatly reduce the acute rejection rate in transplant patients, the long-term side effects can be debilitating. Therefore, researchers are seeking to develop new immunosuppressive regimens that induce maximal levels of immunosuppression with minor side effects. Rosmarinic acid (Ros A) is a secondary metabolite of certain herbs and has multiple biological activities, including anti-inflammatory effects. Here, we have investigated whether treatment of mice with a combination of Ros A and anti-CD154 monoclonal antibody (MR1) improves islet allograft survival in a murine model. After transplantation, the mice were treated with either Ros A, MR1, or both (the "double" treatment). Allograft survival was prolonged in the double-treated animals compared to animals that received only Ros A or MR1. As is the case with the single-treated animals at 15 days after transplantation, the double-treated recipients did not display a significant decrease in the expression of cytokines or the population of activated T cells. Infiltrating CD3+ T cells were reduced in the MR1- or double therapy relative to control or RosA group. However, at the same time point, double-treated graft showed fewer apoptotic cells and increased expression of insulin and glucagons, compared to the single-treatment groups. Furthermore, long-term (>150 days) allografts that were received with double therapy exhibited larger islet clusters and contained more insulin- and glucagon-positive cells, relative to the MR1-treated grafts. In conclusion, treatment with both Ros A and MR1 has a synergistic effect in murine islet allotransplantation.
Animals ; Antibodies, Monoclonal/*pharmacology ; Apoptosis/drug effects ; CD40 Ligand/*immunology ; Cinnamates/*pharmacology ; Cytokines/biosynthesis ; Depsides/*pharmacology ; Diabetes Mellitus, Experimental ; Flow Cytometry ; Glucose/metabolism ; Glucose Tolerance Test ; Graft Survival/*drug effects ; In Situ Nick-End Labeling ; Injections, Intraperitoneal ; Islets of Langerhans/drug effects/pathology ; *Islets of Langerhans Transplantation ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Time Factors ; Transplantation, Homologous

OBJECTIVETo study the effect of total saponins from Entada phaseoloides (TSEP) on islet morphology and skeletal muscle PI3K pathway-related protein expression of type 2 diabetic rats.

METHODType 2 diabetic rats were induced by high-fat diet and low-dose streptozotocin and then randomly divided into 5 groups, i.e. the normal control, the model group, the positive control drug (200 mg x kg(-1) metformin), the low-dose TSEP (25 mg x kg(-1)) group and the high-dose TSEP (50 mg x kg(-1)). Three weeks later, the islet morphology of rat pancreas were observed by HE staining, and protein expressions of insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), protein tyrosine phosphatase-1B (PTP-1 B) and glucose transporter 4 (GLUT4) in rat skeletal muscle were detected by Western blot.

RESULTCompared with the modal group, TSEP administration groups showed relatively normal structures, clear pancreatic cells and intact capsula structures in pancreatic tissue pathological sections, with the number of pancreatic islets close to the normal control group. Meanwhile, above TSEP administration groups showed increased IRS-1, PI3K and GLUT4 protein expressions in their skeletal muscle tissues and decreased PTP-1B protein expression compared with the model group.

CONCLUSIONTSEP has an effect on protecting pancreatic tissues of type 2 diabetic rats and intervening in abnormal expression of proteins in skeletal muscle tissues.

Animals ; Diabetes Mellitus, Type 2 ; drug therapy ; Fabaceae ; chemistry ; Glucose Transporter Type 4 ; analysis ; Islets of Langerhans ; drug effects ; pathology ; Male ; Muscle, Skeletal ; drug effects ; pathology ; Phosphatidylinositol 3-Kinases ; analysis ; Rats ; Rats, Sprague-Dawley ; Saponins ; therapeutic use

OBJECTIVE: To investigate the effect of oral administration of insulin on insulitis beta cell apoptosis and diabetes in non-obese diabetic (NOD) mice, and to explore the mechanism of immune tolerance induced by insulin. METHODS: Eighty-six female NOD mice were randomly divided into an insulin group (n=43) and a phosphate buffered saline (PBS) group (n=43). From 4 weeks of age, the recombinant human insulin (Humulin R) 1 mg (70 microL) was administrated in the oral insulin group and 70 microL PBS in the control group respectively, twice per week before 12 weeks of age and then once weekly until 30 weeks. Insulitis and beta cell apoptosis of islets were observed at 12 weeks. IL-4 and IFN-gamma in the sera were measured by enzyme linked immunosorbent assay (ELISA). The expression levels of I-Abeta(g7), IL-4, IFN-gamma, IL-1beta, Fas and TGF-beta mRNA of islets, and IL-4, IFN-gamma, TGF-beta mRNA of Peyer's patch were measured by reverse transcription-polymerase chain reaction (RT-PCR) at 12 weeks. RESULTS: The incidences in the insulin group were significantly lower than those in the PBS group (55.6% vs 85.7% at 30 weeks, 70.4% vs 96.4% at 52 weeks, P<0.05). The insulitis scores in the insulin group were lower than those in the PBS group, but there was no statistical significance. Fas expression on islets and apoptotic beta cell rates in the insulin group were lower than those in the PBS group (P<0.05). In the insulin group, serum IL-4 levels were higher, and IFN-gamma levels were lower than those in the PBS group (P<0.05). The levels of I-Abeta(g7), IFN-gamma, IL-1beta and Fas mRNA transcription in islets and IFN-gamma mRNA transcription in Peyer's patch were both lower in the insulin group, and IL-4, TGF-beta mRNA levels were higher than those in the PBS group (P<0.05). CONCLUSION The specific autoantigen insulin may induce the immune tolerance and prevent the diabetes in NOD mice, but it cannot block the progression of insulitis. Oral administration of insulin can induce the regulatory T cells, and make Th1 to Th2 cytokine shifts in the system and islets, thus preventing the Fas-mediated beta-cell apoptosis and diabetes.
Administration, Oral ; Animals ; Apoptosis ; drug effects ; Cytokines ; metabolism ; Diabetes Mellitus, Type 1 ; drug therapy ; pathology ; Female ; Insulin, Regular, Human ; administration & dosage ; pharmacology ; Islets of Langerhans ; cytology ; drug effects ; Mice ; Mice, Inbred NOD ; Th1-Th2 Balance ; fas Receptor ; metabolism

To investigate the semi-quantitative method for evaluating the lipid accumulation in pancreas, the KKAy mice, a classical type 2 diabetes mellitus model mice, were used and treated with rosiglitazone (Rosi); and the age-matched C57BL/6J mice were used as normal control. Pancreas was fixed quickly for histological examination with HE staining. For the estimation of the lipid accumulation in pancreas, semi-quantitative method was designed: the number and the size of islet, lipid accumulation in islet and in exocrine gland were observed and the integrative score calculated under the microscope, separately. In KKAy mice, the characteristics of the increased amount of islet, the enlarged area of islet, an abundance of large vacuolations, lipid droplets, and fat proliferation were exposed frequently, and the integrative score increased 2.1 folds compared with that in C57BL/6J mice. Meanwhile, the levels of serum glucose, insulin, and triglyceride (TG) were 1.7, 18.0, and 9.0 times as those in C57BL/6J mice, respectively. With the rosiglitazone (10 mg x kg(-1)) treatment, compared with that in KKAy mice, the pancreatic pathological changes were ameliorated significantly, and the integrative score in KKAy + Rosi mice decreased by 28.9%; and the levels of serum glucose, insulin, and triglyceride decreased by 48.3%, 81.3% and 64.1%, respectively. It showed there is a correlation between the pancreatic pathological semi-quantitative score and the values of serum parameters. In conclusion, this semi-quantitative scoring method is simple and objective for the evaluation of lipid accumulation in pancreas of mice.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; metabolism ; pathology ; Female ; Hypoglycemic Agents ; pharmacology ; Insulin ; blood ; Islets of Langerhans ; metabolism ; pathology ; Lipid Metabolism ; drug effects ; Mice ; Mice, Inbred C57BL ; Pancreas ; metabolism ; pathology ; Random Allocation ; Thiazolidinediones ; pharmacology ; Triglycerides ; blood

To investigate whether BCG, lymphtoxin (LT) or bee venom (BV) can prevent insulitis and development of diabetes in non-obese diabetic (NOD) mice, we measured the degree of insulitis and incidence of diabetes in 24 ICR and 96 female NOD mice. NOD mice were randomly assigned to control, BCG-, LT-, and BV-treated groups. The BCG was given once at 6 weeks of age, and LT was given in 3 weekly doses from the age of 4 to 10 weeks. The BV was injected in 2 weekly doses from the age of 4 to 10 weeks. Diabetes started in control group at 18 weeks of age, in BCG group at 24 weeks of age, and in LT- or BV-treated group at 23 weeks of age. Cumulative incidences of diabetes at 25 weeks of age in control, BCG-, LT-, and BV-treated NOD mice are 58, 17, 25, and 21%, respectively. Incidence and severity of insulitis were reduced by BCG, LT and BV treatment. In conclusion, these results suggest that BCG, LT or BV treatment in NOD mice at early age inhibit insulitis, onset and cumulative incidence of diabetes.
Adjuvants, Immunologic/pharmacology* ; Age Factors ; Animal ; Bee Venoms/pharmacology* ; Cholesterol/blood ; Diabetes Mellitus/prevention & control* ; Diabetes Mellitus/immunology ; Diabetes Mellitus, Insulin-Dependent/prevention & control* ; Diabetes Mellitus, Insulin-Dependent/immunology ; Disease Models, Animal ; Female ; Islets of Langerhans/pathology* ; Islets of Langerhans/drug effects ; Lymphotoxin/pharmacology* ; Mice ; Mice, Inbred NOD ; Mycobacterium bovis/immunology* ; Triglycerides/blood

OBJECTIVETo study the protective effect of islet xenograft and its possible mechanism of high expression of heme oxygenase-1 (HO-1) in donor pancreas islet induced by cobalt protoporphyrin (CoPP).

METHODSMale SD rats and C57BL/6 mouse were used as donors and recipients respectively. Donors were divided into 3 groups according to different pretreatment 24 hours before donation: control group (injected intraperitoneally with NaCl), induce group [injected intraperitoneally with cobalt-protoporphyrin (CoPP)], block group (injected intraperitoneally with CoPP and zinc protoporphyrin simultaneously). A modified approach was used for islet isolation.Recipients were rendered diabetic by intraperitoneal injection of streptozotocin. Islets were transplanted into mouse subrenal capsule. Postoperative mouse glycemia were monitored daily and normoglycemia time was compared among each group. The receptor mouse serum IL-10 was detected by ELISA approach, and real-time PCR was used to check the expression of IL-10 mRNA in islet graft tissues. The graft tissues were observed for the lymphocyte infiltration after HE staining.

RESULTSDiabetes mice accepted islets untreated, induced or blocked maintained the euglycemia for (9.3 +/- 1.4), (16.3 +/- 1.5) and (9.7 +/- 1.0) d respectively. The xeno-islets presented HO-1 over-expression survived much longer than that absent (P < 0.05), it was no significance between control group and block group (P > 0.05). The mouse islet serum IL-10 content after induction was (73.0 +/- 9.7) pg/ml, significantly higher than (30.6 +/- 3.9) pg/ml of the untreated group and (32.1 +/- 5.9) pg/ml of the blocked group (P < 0.05), there was no difference between control group and block group (P > 0.05). Moreover, the IL-10 mRNA expression up-regulated statistic significantly in HO-1 induced islet xeno-graft. Pathological examination showed that the graft lymphocyte infiltration of the induced group was obviously less serious than the other two groups.

CONCLUSIONSThe higher expression of HO-1 induced by CoPP in vivo would significantly prolong graft survival time and its mechanism could be related to immune modulation of IL-10.

Animals ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; surgery ; Graft Survival ; Heme Oxygenase-1 ; drug effects ; metabolism ; Interleukin-10 ; metabolism ; Islets of Langerhans ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Pancreas Transplantation ; Protoporphyrins ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Subrenal Capsule Assay ; Transplantation, Heterologous

This animal experiment was aimed at the questions whether high glucose concentration inhibits insulin secretion (glucose toxicity, GT) of beta-cell of islets from SHR and Wistar-Kyoto (WKY) rat and whether adrenomedullin (AM) enhances GT. Ten 6-week-old SHRs (test group) and ten 10-week-old Wistar-Kyoto rats (WKY) (control group) were selected. RAMI-1640 medium containing 5.6 mM glucose (normal glucose group) and 20 mM glucose (high glucose group) were applied. Various concentrations of AM (0, 10(-8), 10(-7), 10(-6) M) and RPMI-1640 medium containing high glucose were mixed, respectively. The isolated islets from rats were put into 12-well plates (90 islets/well). The islets were incubated in RAMI-1640 medium containing normal or high glucose for one hour. Then the supernatants from both incubations were determined by RIA for insulin. In SHR group, the insulin concentration in supernatants gained from high glucose group without AM was lower than that from normal glucose group (19.9+/-6.6 vs 60.9+/-33.6 mU/L, P<0.05). With the increment of the concentration of AM, insulin concentration in supernatants from islets incubated in high glucose and various concentrations of AM tended to be low further (19.9+/-6.6 vs 22.2+/-8.0 vs 21.5+/-5.6 vs 17.9+/-3.6 mU/L). The changing tendency in control group was the same as in SHR group. When the islets were incubated in normal glucose and high glucose medium, the insulin concentration in supernatant significantly decreased in SHR group compared with that in control group (P<0.01). The insulin secretion was inhibited by high glucose in beta-cell of islets from SHR and WKY. The results suggest GT to beta-cell of islets from SHR and WKY. AM tended to inhibit insulin secretion in a dose-dependent manner in beta-cell of islets from SHR and WKY. The inhibition of insulin secretion caused by high glucose in beta-cell of islets from SHR was more remarkable than from WKY. This may be related to secretion dysfunction in beta-cell of islets from SHR.
Adrenomedullin ; Animals ; Blood Glucose ; metabolism ; Cells, Cultured ; Female ; Glucose ; pharmacology ; Hyperglycemia ; blood ; Hypertension ; metabolism ; pathology ; Insulin ; secretion ; Insulin Resistance ; Islets of Langerhans ; drug effects ; pathology ; secretion ; Male ; Peptides ; pharmacology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY