STZ-diabetic Rats Research Articles

Immune Reactive Ezrin Surface Area Increases in Glomerular Podocytes of STZ Diabetic Rats Precede Their Detachment, Is Prevented by Phlorizin But Not by Insulin

Glomerular tuft immune reactive Ezrin surface area (EzA) and fraction of EzA to total glomerular tuft area significantly increased, indicating podocyte growth, rounding and altered cytoskeletal interactions at 1 week of STZ diabetes. Podocyte number per glomerulus (WT1+ nuclei) did not change indicating no detachment, but density decreased due to tuft hypertrophy. Treatment with PLZ or Insulin for one week, prevented increase in proteinuria and hyperglycemia but not the decrease in podocyte density. PLZ but not Insulin prevented increase in ezrin positive area in glomeruli and per podocyte. In podocytes in culture neither 25 mM glucose with or without PLZ (2.5 or 25 uM) altered Ezrin expression measured in western blots. In summary, the Ezrin positive glomerular surface area increase seen after 1 week of STZ diabetes, reflects altered podocyte morphology and cytoskeletal interactions, prevented by PLZ but not by insulin. Ezrin area increase preceded podocyte detachment and in podocytes in culture is not associated with increases in podocyte Ezrin protein expression. It is a likely precursor of shape changes in podocytes and of alterd interactions with basement membrane that contribute to detachment and thickening. Glomerular capillary tuft hypertrophy and reduced podocyte density persisted despite PLZ or insulin treatments, independently of levels of glycemia and of proteinuria.

Diabetic Encephalopathy Affecting Mitochondria and Axonal Transport Proteins.

Introduction:Diabetic encephalopathy is described as any cognitive and memory impairments associated with hippocampal degenerative changes, including the neurodegenerative process and decreased number of living cells. Mitochondrial diabetes (MD) appears following activation of mutant mitochondrial DNA and is a combination of diabetes and cognitive deficit. In this research, we showed the correlation of diabetic encephalopathy, dysfunctional mitochondria, and changes in the expression of axonal transport proteins (KIF5b, Dynein).Methods:Twenty-four male Wistar rats were divided into three groups: (n=8 in each group):1. Control + saline; 2. Diabetic, and 3. Diabetic + insulin. Before starting the experiments, the animals with blood sugar lower than 150 mg/dL entered the study. Diabetes induction was carried out by Intraperitoneal (IP) Streptozotocin (STZ) administration. Fasting Blood Sugar (FBS) and body weight was checked after the first week and at the end of the eighth week. Then, behavioral studies (elevated plus maze, Y-maze, and passive avoidance learning) were performed. After behavioral studies, blood samples were taken to measure serum insulin level and HgbA1c. Next, fresh hippocampal tissue was collected. Gene expression of motor proteins was assessed by real-time PCR and mitochondrial membrane potential by rhodamine123.Results:Our results showed the impairment of HgbA1c, serum insulin, FBS, and weight in the diabetic group (P<0.05). Behavioral tests revealed different degrees of impairment in diabetic rats (P<0.05). KIF5b mRNA expression increased in the hippocampus (P<0.05) with no change in dynein gene expression. These changes were associated with abnormal mitochondrial membrane potential (P<0.05).Conclusion:KIF5b mRNA up-regulation in hippocampal neurons of STZ-diabetic rats is a factor that can be involved in abnormal axonal transport and decreased MMP, leading to impairment of mitochondrial function. These manifestations showed mitochondrial dysfunction in diabetes and resulted in abnormal behavioral tests and diabetic encephalopathy.

Triglyceride-lowering effect of the aldose reductase inhibitor cemtirestat-another factor that may contribute to attenuation of symptoms of peripheral neuropathy in STZ-diabetic rats.

Hyperglycemia is considered a key risk factor for development of diabetic complications including neuropathy. There is strong scientific evidence showing a primary role of aldose reductase, the first enzyme of the polyol pathway, in the cascade of metabolic imbalances responsible for the detrimental effects of hyperglycemia. Aldose reductase is thus considered a significant drug target. We investigated the effects of cemtirestat, a novel aldose reductase inhibitor, in the streptozotocin-induced rat model of uncontrolled type 1 diabetes in a 4-month experiment. Markedlyincreased sorbitol levels were recorded in the erythrocytes and the sciatic nerve of diabetic animals. Osmotic fragility of red blood cells was increased in diabetic animals. Indices of thermal hypoalgesia were significantly increased in diabetic rats. Tactile allodynia, recorded in diabetic animals in the early stages, turned to mechanical hypoalgesia by the end of the experiment. Treatment of diabetic animals with cemtirestat (i) reduced plasma triglycerides and TBAR levels; (ii) did not affect the values of HbA1c and body weights; (iii) reversed erythrocyte sorbitol accumulation to near control values, while sorbitol in the sciatic nerve was not affected; (iv) ameliorated indices of the erythrocyte osmotic fragility; and (v) attenuated the symptoms of peripheral neuropathy more significantly in the middle of the experiment than at the end of the treatment. Taking into account the lipid metabolism as an interesting molecular target for prevention or treatment of diabetic peripheral neuropathy, the triglyceride-lowering effect of cemtirestat should be considered in future studies. The most feasible mechanisms of triglyceride-lowering action of cemtirestat were suggested.

Diabetic Encephalopathy Affects Mitochondria and Axonal Transport Proteins

Introduction Diabetic encephalopathy is described as any cognitive and memory impairments associated with hippocampal degenerative changes, including the neurodegenerative process and decreased number of living cells. Mitochondrial diabetes (MD) appears following activation of mutant mitochondrial DNA and is a combination of diabetes and cognitive deficit. In this research, we showed the correlation of diabetic encephalopathy, dysfunctional mitochondria, and changes in the expression of axonal transport proteins (KIF5b, Dynein). Methods Twenty-four male Wistar rats were divided into three groups: (n=8 in each group):1. Control + saline; 2. Diabetic, and 3. Diabetic + insulin. Before starting the experiments, the animals with blood sugar lower than 150 mg/dL entered the study. Diabetes induction was carried out by Intraperitoneal (IP) Streptozotocin (STZ) administration. Fasting Blood Sugar (FBS) and body weight was checked after the first week and at the end of the eighth week. Then, behavioral studies (elevated plus maze, Y-maze, and passive avoidance learning) were performed. After behavioral studies, blood samples were taken to measure serum insulin level and HgbA1c. Next, fresh hippocampal tissue was collected. Gene expression of motor proteins was assessed by real-time PCR and mitochondrial membrane potential by rhodamine123. Results Our results showed the impairment of HgbA1c, serum insulin, FBS, and weight in the diabetic group (P<0.05). Behavioral tests revealed different degrees of impairment in diabetic rats (P<0.05). KIF5b mRNA expression increased in the hippocampus (P<0.05) with no change in dynein gene expression. These changes were associated with abnormal mitochondrial membrane potential (P<0.05). Conclusion KIF5b mRNA up-regulation in hippocampal neurons of STZ-diabetic rats is a factor that can be involved in abnormal axonal transport and decreased MMP, leading to impairment of mitochondrial function. These manifestations showed mitochondrial dysfunction in diabetes and resulted in abnormal behavioral tests and diabetic encephalopathy.

Antihyperglycemic activity of Porphyridium cruentum biomass and extra-cellular polysaccharide in streptozotocin-induced diabetic rats

Porphyridium cruentum, known as red microalga, is able to produce extra-cellular polysaccharides (EPs) that have beneficial health effects. In this study, the effect of P. cruentum biomass and EPs with various doses was studied in streptozotocin (STZ)-induced diabetic rats to determine their antihyperglycemic activity and its potential mechanism. The doses of biomass were 600, 1200 and 1800 mg/kg body weight (BW) while the doses of EPs were 150, 300 and 450 mg/kg BW. P. cruentum biomass and EPs could slightly reduce food intake in STZ-diabetic rats as compared with diabetic group. After a 14-day treatment, P. cruentum EPs could decrease blood glucose levels of STZ-induced diabetic rats while P. cruentum biomass at all doses could not. P. cruentum EPs was as effective as glibenclamide in lowering blood glucose levels of diabetic rats. In addition, P. cruentum EPs could significantly increase (p < 0.05) Langerhans islets areas, the number of β-cells and the height of intestinal villi. Treatment with 450 mg/kg BW of EPs resulted in the most effective antihyperglycemic activity. Thus, P. cruentum has the potential to resolve hyperglycemic and diabetic problems.

Responsiveness of lumbosacral superficial dorsal horn neurons during the voiding reflex and functional loss of spinal urethral-responsive neurons in streptozotocin-induced diabetic rats.

Sensory information from the lower urinary tract (LUT) is conveyed to the spinal cord to trigger and co-ordinate micturition. However, it is not fully understood how spinal dorsal horn neurons are excited during the voiding reflex. In this study, we developed an in vivo technique allowing recording of superficial dorsal horn (SDH) neurons concurrent with intravesical pressure (IVP) during the micturition cycle in both normal and diabetic rats. Lumbosacral dorsal horn neuronal activity and IVP were recorded from urethane-anesthetized naive and streptozotocin (STZ)-induced diabetic rats. Saline was continuously perfused into the urinary bladder through a cannula to induce micturition. We classified SDH neurons into bladder- and urethral-responsive neurons, based on their responsiveness during the voiding reflex. Bladder-responsive SDH neurons responded to the rapid increase in IVP at the start of voiding. In contrast, urethral-responsive SDH neuronal firing increased at the peak IVP and their firing lasted during the voiding phase (the high-frequency oscillations). Urethral-responsive SDH neurons were more sensitive to capsaicin, received C afferent fiber inputs, and were rarely detected in STZ-diabetes rats. Administration of a cyclohexenoic long-chain fatty alcohol (TAC-302), which is reported to promote neurite outgrowth of peripheral nerves in STZ-diabetic rats, prevented the functional loss of spinal urethral response. Sensory information from the bladder and urethra is conveyed separately to different groups of SDH neurons. Functional loss of spinal urethral sensory information through unmyelinated C afferent fibers may contribute to diabetic bladder dysfunction.

PET Imaging of Vesicular Monoamine Transporter 2 in Early Diabetic Retinopathy Using [18F]FP-(+)-DTBZ.

Diabetic retinopathy (DR) is characterized by dopaminergic neuron loss in the retina of the eyes. [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) positron emission tomography (PET) has been shown to detect dopaminergic neuron loss. The study is to investigate the feasibility of PET imaging with [18F]FP-(+)-DTBZ for early diagnosis of diabetic retinopathy (DR) in diabetes mellitus (DM) rat models. The DM rat model was established by a single intraperitoneal injection of streptozotocin (STZ) (65 mg/kg). After 4 weeks, 8 weeks, and 12 weeks of STZ injection, the retinas of the rats were evaluated by electroretinogram (ERG), color fundus photography (CFP), fundus fluorescein angiography (FFA), and small animal PET scan with [18F]FP-(+)-DTBZ by targeting vesicular monoamine transporter 2 (VMAT2). [18F]FP-(+)-DTBZ uptake in retina was quantified as standardized uptake value (SUV). Immunofluorescence staining and Western blot were also performed to confirm the expression level of VMAT2 in retina. ERG dysfunction was observed at 8 weeks in STZ-diabetic rats, evidenced by smaller amplitudes of oscillatory potentials (OPs) when compared with OPs in normal rats. CFP and FFA showed no significant difference in vascular leakage and neovascularization between STZ-diabetic retinas and normal ones until 8 weeks. PET imaging revealed that the SUV of [18F]FP-(+)-DTBZ was significantly lower in the STZ-diabetic retinas compared with the normal ones as early as of week 4. The results from immunofluorescence staining and Western blots confirmed the early findings in PET imaging studies. Early DR can be non-invasively detected with PET imaging using [18F]FP-(+)-DTBZ targeting VMAT2. The expression level of VMAT2 in retina may act as a new biomarker for early DR diagnosis.

Water-soluble C60 fullerene ameliorates astroglial reactivity and TNFa production in retina of diabetic rats

The complications of both first and second types of diabetes mellitus patients are important cause of decline in quality of life and mortality worldwide. Diabetic retinopathy (DR) is a widespread complication that affects almost 60% of patients with prolonged (at least 10–15 years) diabetes. The critical role of glial cells has been shown in retinopathy initiation in the last decades. Furthermore, glial reactivity and inflammation could be key players in early pathogenesis of DR. Despite the large amount of research data, the approaches of effective DR therapy remain unclear. The progress of DR is accompanied by pro-inflammatory and pro-oxidative changes in retinal cells including astrocytes and Muller cells. Glial reactivity is a key pathogenetic factor of various disorders in neural tissue. Fullerene C60 nanoparticles were confirmed for both antioxidant and anti-inflammatory capability. In the presented study glioprotective efficacy of water-soluble hydrated fullerene C60 (C60HyFn) was tested in a STZ-diabetes model during 12 weeks. Exposure of the STZ-diabetic rat group to C60HyFn ameliorated the astrocyte reactivity which was determined via S100β and PARP1 overexpression. Moreover, C60HyFn induced the decrease of TNFα production in the retina of STZ-diabetic rats. By contrast, the treatment with C60HyFn of the normal control rat group didn’t change the content of all abovementioned markers of astrogliosis and inflammation. Thus, diabetes-induced abnormalities in the retina were suppressed via the anti-oxidant, anti-inflammatory and glioprotective effects of C60HyFn at low doses. The presented results demonstrate that C60HyFn can ensure viability of retinal cells viability through glioprotective effect and could be a new therapeutic nano-strategy of DR treatment.

EXPLORATION OF PROTECTIVE EFFECT OF HYDROALCOHOLIC EXTRACT OF ALSTONIA SCHOLARIS BARK IN STZ-INDUCED EARLY DIABETIC NEPHROPATHY MODEL IN RATS

Alstonia scholaris (fam. Apocynaceae) is an indigenous plant used traditionally for the treatment of diabetes and associated complications. However the nephroprotective potential of the plant is not scientifically evaluated. Objective of the present was to investigate renal protective activity of hydroalcoholic extract of A. scholaris bark (HEAS) in streptozotocin (STZ)-induced early diabetic nephropathy in rats and to focus on its possible mechanism of action. Experimental diabetes was induced in Wistar rats using single intraperitoneal injection of streptozotocin (65 mg/kg). Animals were divided in five groups (n=6) and treated with 150 mg/kg and 300 mg/kg HEAS for 4 weeks. At the end of study period, fasting blood glucose, blood urea nitrogen (BUN), serum creatinine, total proteins, serum albumin, serum insulin and glycosylated haemoglobin, superoxide dismutase, catalase, reduced glutathione and MDA in kidney were evaluated. Urine was analyzed for albumin, total proteins and creatinine clearance. Kidney and pancreas were subjected for histopathology. Significant decrease in fasting blood glucose, creatinine, albumin, BUN, total proteins and urinary total proteins was observed. Significant improvement in serum insulin, glycosylated Hb, oxidative stress parameters of kidney including superoxide dismutase, catalase and reduced glutathione has been observed in HEAS treated diabetic rats. Histopathology of kidney and pancreatic tissues showed structural improvement. Present study has revealed that HEAS prevented the progression of diabetic nephropathy in STZ-diabetic rats by improving the disturbed glucose homeostasis and by amelioration of renal oxidative stress.

Isolation and Characterization of metabolites from Clathria procera Ridley extract and Evaluation of its antidiabetic ef-fects in Streptozotocin-induced diabetic rats

Diabetes mellitus is a lethal metabolic disorder in humankind, which induce chronic complications. The present study investigated the effects of ethyl acetate extract from C. procera (EAE) and its isolates on antioxidant and in vitro antidiabetic activities, along with effects of EAE on plasma blood glucose concentrations in STZ-diabetic rats. For the first time, two known metabolites- N-((2S,3R,E)-1,3-dihydroxyoctadec-4-en-2-yl)stearamide (1) and N-((2S,3R,4E,8E)-1,3-dihydroxyoctadeca-4,8-dien-2-yl)palmitamide (2) are reported from EAE. 1, 2 and EAE depicted significant DPPH, superoxide free radicals, α-glucosidase and α-amylase inhibitory profile, indeed, 1 and 2 showed mild inhibitory profile against aldose reductase. In addition, the EAE (200 mg/kg b.w) revealed significant reduction in plasma glucose, body weight, total cholesterol, total glycerides and LDL levels in STZ-induced diabetic rats. The HDL levels were markedly augmented in EAE treated diabetic rats, when compared with control group. EAE abolished the increased lipid peroxidation in pancreas, liver and kidneys. The histopathological examination of pancreas of EAE protected the Langerhans islets with the number of islet cells were found statistically significant, when compared to diabetic control pancreas. Our data suggest that the C. procera has a potentiality to act against diabetes (both, in vitro and in vivo models) by inhibiting particularly digestive enzymes namely α-glucosidase and α-amylase, however further studies are required for proper establishment of mechanism of action and validating clinical effects.

In contrast to Western diet, a plant-based, high-fat, low-sugar diet does not exacerbate retinal endothelial injury in streptozotocin-induced diabetes.

Controversy remains about how diet affects the vascular endothelial dysfunction associated with disordered insulin-glucose homeostasis. It is postulated that the type and level of certain macronutrients contribute to endothelial dysfunction in vascular diabetes complications. However, it is not well understood how specific macronutrients affect the molecular inflammatory response under conditions of hyperglycemia. Here, we examined retinal microvascular endothelial injury in streptozotocin (STZ)-diabetic rats fed a laboratory Western diet (WD). WD, characterized by its high content of saturated fat, cholesterol, and sugar, significantly increased retinal leukocyte accumulation and endothelial injury in the STZ-diabetic rats. Suppression of endothelial NF-κB signaling in the STZ model reduced the WD-induced increase in leukocyte accumulation. To isolate the effect of dietary fat, we generated high-fat diets with varying fatty acid balance and type. These diets contained moderate amounts of carbohydrates but no sugar. We found that neither high levels of saturated or unsaturated fats per se increased retinal leukocyte accumulation and endothelial injury in the STZ-diabetic rat model but that the combination of high levels of dietary cholesterol with specific saturated fatty acids that are abundant in WD exacerbated leukocyte accumulation and endothelial injury in the retinas of STZ-diabetic rats.-Barakat, A., Nakao, S., Zandi, S., Sun, D., Schmidt-Ullrich, R., Hayes, K. C., Hafezi-Moghadam, A. In contrast to Western diet, a plant-based, high-fat, low-sugar diet does not exacerbate retinal endothelial injury in streptozotocin-induced diabetes.

Administration of human umbilical cord blood mononuclear cells restores bladder dysfunction in streptozotocin-induced diabetic rats.

This study evaluated the effect of human umbilical cord blood mononuclear cells (HUCB-MNCs) on bladder dysfunction in streptozotocin (STZ; 35 mg/kg, i.v.)-induced diabetic rats. Adult male Sprague-Dawley rats (n = 30) were equally divided into three groups: control group, STZ-diabetic group, and HUCB-MNC-treated group (1 × 106 cells). HUCB-MNCs were isolated by density gradient centrifugation from eight healthy donors and injected into the corpus cavenosum in STZ-diabetic rats 4 weeks after the induction of diabetes. Studies were performed 4 weeks after HUCB-MNC or vehicle injection. In vitro organ bath studies were performed on bladder strips, whereas protein expression of hypoxia-inducible factor (HIF)-1α, vascular endothelial growth factor (VEGF), and α-smooth muscle actin (SMA) in the bladder and the ratio of smooth muscle cells (SMCs) to collagen were determined using western blotting and Masson trichrome staining. Neurogenic contractions of detrusor smooth muscle strips were 55% smaller in the diabetic group than control group (P < 0.05); these contractions were normalized by HUCB-MNC treatment. In addition, HUCB-MNC treatment restored the impaired maximal carbachol-induced contractile response in detrusor strips in the diabetic group (29%; P < 0.05). HUCB-MNC treatment improved the KCl-induced contractile response in the diabetic bladder (68%; P < 0.05), but had no effect on ATP-induced contractile responses. Increased expression of HIF-1α and VEGF protein and decreased expression of α-SMA protein and the SMC/collagen ratio in diabetic rats were reversed by HUCB-MNC. Administration of HUCB-MNCs facilitates bladder function recovery, which is likely related to downregulation of HIF-1α expression and attenuation of fibrosis in STZ-diabetic rats.

2319-PUB: Glycemic Control with XeriSol Regular Insulin and Lispro Insulin: Comparative PK-PD with Humalog and Humulin in STZ Diabetic Rats

Insulin therapy is the primary treatment option for patients with type 1 and 2 diabetes. Despite considerable advances in insulin chemistry, delivery, and pharmacology, only a small percentage of diabetic patients achieve near normal glycemic levels. Xeris has developed novel room temperature stable insulin formulations that may offer duration of efficacy advantages over commercially available options. Streptozotocin (65 mg/kg) treated SD rats were given co-formulations of PRAM and Regular Insulin (RI) or Lispro Insulin (LISPRO) as a single injection and compared with dual injection of commercial Symlin, Humulin, or Humalog. Blood samples were evaluated for plasma glucose and PK. A sparse sampling PK scheme resulted in ∼30% CV for glucose values. Mean glucose profiles with reductions in glucose AUC by treatment (efficacy). XeriSol™ insulins showed comparable efficacy and pharmacokinetic profiles commercial products with up to 4 hours of glycemic control. Xerisol formulations of Insulin and Lispro showed trends for lower sustained means (30-240 min) for glucose levels and slightly longer half-lives than comparative doses of commercial Humulin and Humalog. Disclosure S. Thohan: None. M.J. Donovan: None. W.T. Hu: None. M.S. Choi: None. D.M. Hester: None. S.J. Prestrelski: Employee; Self; Xeris Pharmaceuticals, Inc.

2491-PUB: Proinsulin C-Peptide Attenuates Vascular Dysfunctions by Activating Nrf2

We and others demonstrated that insulin C-peptide has biological activities and may prevent tissue damages by diabetes. Our research using STZ diabetic rats and other models suggested that diabetic vascular dysfunctions, e.g., increased vascular permeability and blood flows are caused by oxidative and nitrosative stress initiated from increased NADH redox (reductive stress). However, C-peptide prevented dysfunctions without normalizing redox state and worked in nondiabetic rats. In this study, we further examined modes of actions and investigated its mechanisms. Male Wistar rats were used in animal study. Human de-differentiated adipocytes (DFAT cells) were used for cell culture study. Lentivirus vector expressing LC3-GFP was created to assess autophagy. Regional blood flow was assessed using microsphere. Acute hyperglycemia induced by glucose infusion for 5 hours resulted in increased regional blood flows in retina, sciatic nerve and kidney. Simultaneous infusion of C-peptide up to 16 mg/kg did not prevent the increases, while twice daily subcutaneous injection of 400 µg/kg for 2-days prior to infusion prevented completely. One-day injection was only slightly effective. Bolus i.v. injection of L-lactate 1 mol/kg but not NaCl caused reductive stress and blood flow increase, and this was also prevented by twice daily 2-days injection of C-peptide. Thus, C-peptide appeared to induce some factors counteracting oxidative stress during 2 days. In DFAT cells, LC3-GFP puncta was increased 3-fold by one time 100 nM C-peptide treatment in 1 hour. This was followed by nuclear localization of Nrf2 transcription factor at 2 hours. At 4 hour, 4-fold increase in Nrf2 target genes, IDH and SRXN1, expression were observed (p&amp;lt;0.05). Similar 35-62% increase in Nrf2 target genes (Idh, Srxn1, Pgd and Hmox) were observed in rat aorta after twice daily 2-days injection of C-peptide. These results suggest that injections of pharmacological dose of C-peptide increase Nrf2 antioxidants expression through activating autophagy. Disclosure F. Lan: None. Y. Lin: None. Z. Gao: None. P. Zhao: None. X. Zhang: None. Y. Shiraishi: None. Y. Ido: None. Funding Japan Society for the Promotion of Science

117-OR: Carvedilol Prevents Impairment of the Counterregulatory Response in Recurrently Hypoglycemic Diabetic Rats

It has been suggested that repeated activation of the adrenergic system during antecedent episodes of hypoglycemia may contribute to the development of counterregulatory failure. We previously showed that treatment with the non-specific β-blocker, carvedilol, can prevent counterregulatory failure in nondiabetic, recurrently hypoglycemic rats. The current study investigated whether carvedilol, can be used to prevent the development of counterregulatory failure in recurrently hypoglycemic diabetic rats. Sprague-Dawley rats were made diabetic with a single injection of streptozotocin (STZ; 60mg/kg; I.P.) One week after the induction of diabetes, carvedilol (4.5mg/kg QID; IP) treatment was started and continued for one week in one subgroup of STZ-diabetic rats. The remaining animals received a saline injection as controls. Three days later, the animals received either 3 bouts of insulin-induced hypoglycemia (RH) over the course of 3 days or they received 3 saline injections. On day 14, the animals underwent a hyperinsulinemic-hypoglycemic clamp to assess the counterregulatory hormone responses. Compared to hypoglycemia-naïve STZ Controls, glucose infusion rates were more than doubled in the STZ+RH animals (P&amp;lt;0.001) and this was associated with an ∼50% reduction in the epinephrine response to hypoglycemia. Treatment of STZ+RH animals with carvedilol improved the epinephrine responses to hypoglycemia. Of note, RH did not further diminish the glucagon response in STZ-diabetic rats. Our data suggests that carvedilol may be useful to prevent impairments in the counterregulatory response during recurring episodes of hypoglycemia in diabetic animals. Disclosure R. Farhat: None. O. Chan: Research Support; Self; Zucara Therapeutics Inc. G. Su: None. E. De Santana Van Vliet: None. Funding JDRF; National Institutes of Health

The Hypoglycemic Effects of Ginger and Garlic Administration on Induced Diabetic Rats

This work was designed to investigate the possible hypoglycemic effects of ginger (Zingiber officinal) and garlic (Allium sativum) administration on type 2 diabetesinduced in rats. Seventy male adult albino rats were randomly divided into seven groups of ten animals: Normal Control (Cnt), Diabetic Control (CntD), Ginger Low (GNL), Ginger High (GNH), Garlic Low (GRL), Garlic High (GRH) and a combination group (GNH+GRH). Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ, 65 mg/kg of body weight) in all groups except the Cnt group. Rats were treated with ginger and garlic powders in different doses for 2 months. At the end of experiment, glycated hemoglobin (HbA1c), serum glucose, serum insulin, cholesterol, and high density lipoprotein (HDL)concentrations, low density lipoprotein (LDL), liver glycogen and glucagon levels were estimated.Expression of Glucose-6-Phosphatase and Glucokinase genes in liver samples from each group were normalized with housekeeping gene (s-actin) using reverse transcriptase real time Polymerase chain reaction. Serum insulin and HDL concentrations were significantly (P< 0.05) higherbutbody weight, fasting blood glucose, total cholesterol, LDLand HbA1clevels were significantly (P< 0.05) lower in the Cnt, GNH, GRH and GNH+GRHgroups compared to the CntD, GNL and GRL groups. Liver glycogen level was significantly (P< 0.05) higher and serum glucagon level was significantly (P< 0.05) lower in the combination group only but non significant difference was observed for the other groups. The expression of liver Glucose-6-Phosphatase gene was significantly (P< 0.05) downregulated but the Glucokinase gene was significantly (P< 0.05) upregulated in STZ diabetic rats treated withhigh doses of ginger and garlic powders. This study suggests that ginger and garlic powders can be used to ameliorate type 2 diabetes and might also help in preventing secondary diabetic complications.

"Adjusting internal organs and dredging channel" electroacupuncture treatment prevents the development of diabetic peripheral neuropathy by downregulating glucose-related protein 78 (GRP78) and caspase-12 in streptozotocin-diabetic rats.

The clinical efficacy of electroacupuncture in treating diabetic peripheral neuropathy (DPN) is significant, but the underlying mechanism of action is not clear. Considering that glucose-regulated protein 78 (GRP78) and caspase-12 are major proteins participating in cell apoptosis, we investigated the effects of "adjusting internal organs and dredging channel" electroacupuncture therapy on GRP78 and caspase-12 levels in streptozotocin (STZ)-diabetic rats to elucidate the mechanism of action. Rats were first divided into two groups: one group was rendered diabetic with a single injection of 50 mg/kg STZ, whereas the other normal control group was injected with an equivalent volume of citrate buffer. The STZ-diabetic rats were randomly divided into three groups: model control and electroacupuncture- and mecobalamin-treated groups. After 12 weeks treatment, the therapeutic efficacy of electroacupuncture was assessed using sciatic nerves isolated from rats. In the electroacupuncture group, rats were treated by electroacupuncture for 20 minutes once daily for 6 days each week, with 1 day off, for 12 consecutive weeks. The selected acupressure points include bilateral acupressure points of BL13 (Fehu), BL20 (Pishu), BL23 (Shenshu), LI4 (Hegu), LR3 (faichong), ST36 (Zusanli), and SP6 (Sanyiniiao). Acupressure points were stimulated using a HuaTuo SDZ-V Electric Acupuncture Therapy Apparatus. The acupressure points of BL13 and BL23, as well as SP6 and LR3, were connected on the same side with a dilatational wave of 3 Hz (frequency ratio of 1 : 5) to stimulate the parts of the body to the extent that could be tolerated by the rat. As for the mecobalamin-treated groups, mecobalamin was administrated to rats intragastrically at a dose of 20 mg/kg once daily for 12 consecutive weeks. Immunofluorescence and western blot analysis were used to determine GRP78 and caspase-12 levels in sciatic nerves. In addition, cell apoptosis in sciatic nerves was determined using the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling (TUNEL) assay. Electroacupuncture markedly reduced the pathological injury to sciatic nerves in STZ-diabetic rats. Moreover, electroacupuncture significantly downregulated GRP78 and caspase-12 and reduced cell apoptosis of sciatic nerves in DPN rats. Electroacupuncture improved DPN by downregulating GRP78 and caspase-12 and reducing cell apoptosis of sciatic nerves in STZ-diabetic rats, and further inhibited the occurrence of endoplasmic reticulum stress, thus preventing sciatic nerve injuries.

Nanosized selenium and Loranthus micranthus leaves ameliorate streptozotocin-induced hepato-renal dysfunction in rats via enhancement of antioxidant system, regulation of caspase 3 and Nrf2 protein expression

The investigation of potential health benefits of nano-sized nutriceuticals is recently a major scientific interest. The present study investigated the effect of Selenium and Loranthus micranthus leaves nanoparticles (SeNPs and LMLNPs), on streptozotocin (STZ)-diabetes induced hepato-renal dysfunction in rats. Adult rats were rendered diabetic by a single i.p exposure to 40 mg/kg STZ. Thereafter, rats were treated with 0.1 mg/kg SeNPs or 200 mg/kg LMLNPs, or a combination of both, while 50 mg/kg metformin was used as a standard therapeutic drug. Results indicated that STZ-diabetic rats experienced liver and kidney damage evidenced by a significant elevation in serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and 5′ nucleotidase (5′NT) when compared to non-diabetic control rats. Furthermore, a decrease in activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), Glutathione-S-transferase (GST) and glutathione (GSH) levels was observed, whereas myeloperoxidase (MPO) activities and lipid peroxidation (LPO) levels increased significantly in the negative control group compared to the test groups. Immunohistochemical and western blot analyses showed a corresponding elevation in the expression of apoptotic biomarker-caspase 3 and nuclear erythroid 2-related factor 2 (Nrf2) protein in STZ-diabetes group relative to the test groups. SeNPs and/or LMLNPs significantly ameliorated the various alterations imposed by STZ-diabetes relative to the control group. The chemotherapeutic influence in STZ-diabetic rats could be elicited via augmentation of antioxidant defence systems, regulation of Nfr2 expression, decrease in lipid peroxidation and regulation of apoptosis in the studied tissues.

The Effects of Anacyclus pyrethrum Alcoholic Root Extract on FSH, LH, Testosterone and Sperm Count in Diabetic Male Rats

Background: Diabetes mellitus (DM) is known as a worldwide growing metabolic disorder which reduces fertility. Objectives: The objective of the present study was to evaluate the effect of alcoholic root extract of Anacyclus pyrethrum (AP) on FSH, LH, testosterone and sperm count in diabetic male rats. Methods: This study was conducted on 60 Wistar-Albino male rats divided into six groups: control group (C), and diabetic groups including: control group (DC), placebo receiver (P) which received 50 (DA1), 100 (DA2) and 150 (DA3) mg/kg alcoholic AP root extract during trial period. Diabetes was induced with an intraperitoneal injection of streptozotocin (STZ, 60mg/kg). At the end, animals were anesthetized and blood samples were collected from cervical vessels. Serum FSH and LH were determined by ELISA methods. Serum testosterone was measured by standard laboratory method. Sperm count in epididymis and vas deferens was determined using a hemocytometer. The data were analyzed using SPSS V.11 via ANOVA and Tukey tests. Results were expressed as mean ± SD. Statistical differences were considered significant at P < 0.05. Results: Results showed that the serum FSH, LH, testosterone, epididymis, testis, and body weight in all groups which received AP alcoholic root extract significantly increased compared to groups DC and P. Conclusions: AP alcoholic root extract improved FSH, LH and testosterone hormones and body weight gain in STZ diabetic male rats.

Assessing of Antidiabetic and Ameliorative Effect of&lt;i&gt; &lt;/i&gt;Lupin Seed Aqueous Extract on Hyperglycemia, Hyperlipidemia and Effect on pdx1, Nkx6.1, Insulin-1, GLUT-2 and Glucokinase Genes Expression in Streptozotocin-induced Diabetic Rats

Diabetes mellitus (DM) belong to the major health problems causing mortality and morbidity in the world. Our study aimed to investigate effects of Lupinus Albus (LA) seed extract on streptozotocin (STZ)-induced diabetic rats. Thirty mature Sprague Dawley male rats were used in this study. Three experimental groups were used as follows: GI- Control rats (Normal), GII- Diabetic rats and GIII- Diabetic rats treated with LA aqueous extract (7mg/100g B.wt) by oral gavage. Insulin, Fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c) and serum lipid profile assays of all rats were carried out. Gene expressions of Pancreatic and duodenal homeobox 1 (Pdx-1), homeobox protein (Nkx6.1), insulin-1, liver glucose transporter-2 (GLUT-2) and glucokinase were performed by real-time PCR. Results obtained for diabetic rats orally gavage with LA extract revealed an improvement in insulin with reduction in FBG, HbA1c% and significant improvement in serum lipid profile. Additionally, LA aqueous extract induced a mild increase in expression of biomarkers genes for pancreatic βeta cells (β-cells) function, insulin secretion, liver GLUT-2 and glucokinase when compared to STZ-diabetic rats. This research highlights LA seed extract as a nutraceutical for improving insulin secretion in diabetic rats.