The effect of alloxan-diabetic rat fed with normal, high fat, low protein and high protein diets on the rate of urea production and the activities of enzymes associated with the urea cycle (ornithine transcarbamoylase, E.C. 2.1.3.3, OTC; arginase, E.C. 3.5.5.1) have been studied in intact and isolated perfused liver. The amount of urea excretion was the highest in the high protein diet group. When each diet group was treated with alloxan, total urea excretion showed little differences between each diet group and its corresponding control group with the exception being in the normal diet group. However, the enzyme activity of OTC was increased significantly by alloxan treatment in low and high protein diet groups as compared to corresponding control groups. Similar results were obtained in arginase activity, although the magnitude of the change was less marked. In liver perfusion experiments on rats treated with alloxan, the amount of urea production and changes in OTC and arginase activity were very similar with those in the intact liver. These results suggest that alloxan treatment in normal diet group causes an increase in urea excretion both in intact and perfused liver regardless of changes in enzyme activities and total urea excretion, and enzyme activities are affected by changes in dietary components but the changes of enzyme activities may not correlate with total urea excretion.
Alloxan ; Animal ; Diabetes Mellitus, Experimental/metabolism* ; Dietary Fats/pharmacology* ; Dietary Proteins/pharmacology* ; In Vitro ; Liver/metabolism* ; Male ; Perfusion ; Rats ; Urea/metabolism* ; Urea/urine

OBJECTIVETo investigate the effect of ursolic acid (UA) on the alloxan-induced kidney injury in diabetic mice and explored its possible mechanisms.

METHODSDiabetes mellitus was induced in male Kunming mice by an injection of alloxan (70 mg/kg, i.v.). After 72 hours, blood glucose levels were detected and mice with blood glucose levels over 13.9 mmol/L were considered as diabetic and selected for further experiment. Thirty mice were randomly divided into three groups: control, diabetic and diabetic + UA(35 mg/kg/d, i.g. continuously for 8 weeks). Blood glucose concentration, organ coefficient of kidney, blood urea nitrogen (BUN), creatinine (Cr) as well as renal tissue levels of superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined. Pathology of the renal tissue was measured by hematoxylin-eosin staining.

RESULTSCompared to the control group, blood glucose, organ coefficient of kidney, BUN and Cr increased significantly. In addition, SOD activities was reduced markedly and levels of MDA and inflammatory factors (TNF-α, IL-6) increased significantly. Renal cells from model group rats showed atrophy and disordered after HE staining and infiltration of inflammatory cells also appeared in renal tissue of the model group. These changes were significantly attenuated in the diabetic group treated with UA.

CONCLUSIONUA can significantly relieve renal damage in mice with diabetic nephropathy induced by alloxan, which might be related to decreased blood glucose level, antioxidation effect and inhibiting the production of inflammatory factors such as TNF-α and IL-6.

Alloxan ; adverse effects ; Animals ; Antioxidants ; metabolism ; Blood Glucose ; Blood Urea Nitrogen ; Creatinine ; metabolism ; Diabetes Mellitus, Experimental ; physiopathology ; Diabetic Nephropathies ; chemically induced ; drug therapy ; Interleukin-6 ; metabolism ; Kidney ; physiopathology ; Male ; Mice ; Superoxide Dismutase ; metabolism ; Triterpenes ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the effect of Musa sapientum L. (MS) bark juice in diabetic gastroparesis and its effect on pharmacokinetic of metformin (MET).

METHODSDiabetes was induced in rats by administering alloxan (120 mg/kg) saline solution and maintained for 8 week. All the 18 Sprague-Dawley rats were divided into three groups (n =6 in each group): normal control, diabetic control and MS bark juice. Assessment of diabetes was done by glucose oxidase-peroxidase method on the 3rd day of alloxan administration. The effects of MS bark juice (100 mL/kg) on gastric emptying time, intestinal transit time, contractility of fundus and pylorus as well as gastric acid secretion in chronic diabetic rats were observed after 8 weeks of alloxan administration. The effect of MS bark juice on the pharmacokinetic of orally administered single dose of MET (350 mg/kg) was evaluated on the 57th day of protocol. Any drugs that may reduce the blood glucose level or influence the fibrinolytic system were not used in this study.

RESULTSThe MS bark juice significantly reduced the blood glucose level in the diabetic rats (P<0.01). There was significant decrease in the pylorus motility and increase in the gastric emptying time, intestinal transit time, contractility of fundus, gastric acid secretion in the MS bark juice treated group (P<0.01). There was significant decrease in the time at which drug at a maximum concentration, half life of drug and increase in the maximum concentration of drug in the plasma of MET in MS bark juice treated group as compared to diabetic control group (P<0.01).

CONCLUSIONMS bark juice effectively manages diabetic gastroparesis and thereby improves the bioavailabilty of MET when administered with MS bark juice.

Alloxan ; Animals ; Blood Glucose ; Chromatography, High Pressure Liquid ; Diabetes Mellitus, Experimental ; blood ; complications ; drug therapy ; physiopathology ; Gastroparesis ; blood ; complications ; drug therapy ; physiopathology ; Male ; Metformin ; blood ; pharmacokinetics ; therapeutic use ; Musa ; chemistry ; Plant Extracts ; pharmacology ; therapeutic use ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of aqueous abstract from eucommia ulmoides oliv on the activity of superoxide dismutase (SOD) and alpha-actin expression in the penile tissues of rats with diabetes mellitus (DM) in vitro.

METHODSA diabetes model was established by administration of alloxun twice to Sprague Dawley (SD) rats. Ten diabetic and 10 normal rats were randomly selected and the penile strips of each rat were divided into four equal shares and cultured in two groups, a eucommia ulmoides oliv coculture group (Group A, further dicided into 1 microg/ml, 10 microg/ml and 100 microg/ml subgroups) and a control group (Group B). Seven days later, the activity of SOD in the culture medium was detected by spectrophotometry, and the levels of micro-actin expression in the penile tissues were examined with the immunohistochemical method.

RESULTSCompared with Group B, the activity of SOD in the culture medium in athe 10 and 100 microg/ml subgroups was notably elevated (P < 0.01), and the numbers of immunoreactive positive cells of alpha-actin in the penile tissues remarkably increased (P < 0.01).

CONCLUSIONThe activity of SOD and alpha-actin expression in the penile tissues of diabetic rats in vitro can be increased by eucommia ulmioides oliv.

Actins ; biosynthesis ; Alloxan ; Animals ; Diabetes Mellitus, Experimental ; metabolism ; Dose-Response Relationship, Drug ; Eucommiaceae ; Male ; Penis ; drug effects ; metabolism ; Plant Extracts ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; drug effects ; metabolism

OBJECTIVETo investigate the protective effects of terpenes from fructus corni (TFC) on diabetic cardiomyopathy (DCM).

METHODSDiabetes was produced by a single injection of alloxan (220 mg/kg, i.p.) in mice. The fasting blood glucose of mice were tested 15 days later and that greater than 13.9 mmol/L were regarded as the diabetic mice which were divided randomly into the model and TFC groups. TFC dissolved by physiological saline (P.O, 80 mg/kg) was administrated to the TFC group for successive 8 weeks since the 15th day.

RESULTSCompared to the control group, the weight index increased significantly. The level of superoxide dismutase (SOD) was markedly decreased and malondialdehyde(MDA), the inflammatory factors (TNF-alpha, IL-6) were obviously increased in myocardium. The histopathological examination suggested that myocardial cells disarranged, swelling and the intercellular space increased in model group. It also showed the infiltration of inflammatory cells and fibroblasts in TFC group. The above change was improved significantly.

CONCLUSIONTFC ameliorated the alterations of cardiomyopathy in diabetic mice induced by alloxan. the mechanism might be related to decrease blood glucose, antioxidative stress and inflammatory factors.

Alloxan ; adverse effects ; Animals ; Cornus ; chemistry ; Diabetic Cardiomyopathies ; chemically induced ; metabolism ; prevention & control ; Interleukin-6 ; metabolism ; Male ; Malondialdehyde ; metabolism ; Mice ; Mice, Inbred Strains ; Oxidative Stress ; drug effects ; Superoxide Dismutase ; metabolism ; Terpenes ; pharmacology ; therapeutic use ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDPomegranate (punica granatum) belongs to the family Punicaceae, and its peel has been used as a traditional Chinese medicine because of its efficacy in restraining intestine, promoting hemostasis, and killing parasites. Pomegranate peel has been reported to possess wound-healing properties which are mainly attributed to its polyphenol extracts. The purpose of this study was to investigate the effect of pomegranate peel polyphenols (PPP) gel on cutaneous wound healing in diabetic rats.

METHODSAlloxan-induced diabetic rats were given incisional wounds on each side of the mid-back and then treated daily with PPP gel (polyphenol mass fraction = 30%) post-wounding. Rats were sacrificed on days 4, 7, 14, and 21 post-wounding to assess the rates of wound closure, histological characteristics; and to detect the contents of hydroxyproline, production of nitric oxide (NO), and activities of NO synthase (NOS), as well as the expressions of transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF) in wound tissue.

RESULTSWound closure was significantly shortened when PPP gel was applied to the wounds of diabetic rats. Histological examination showed the ability of PPP gel to increase fibroblast infiltration, collagen regeneration, vascularization, and epithelialization in the wound area of diabetic rats. In addition, PPP gel-treated diabetic rats showed increased contents of hydroxyproline, production of NO, and activities of NOS and increased expressions of TGF-β1, VEGF, and EGF in wound tissues.

CONCLUSIONPPP gel may be a beneficial method for treating wound disorders associated with diabetes.

Alloxan ; Animals ; Diabetes Mellitus, Experimental ; pathology ; physiopathology ; Female ; Gels ; Hydroxyproline ; analysis ; Male ; Nitric Oxide ; biosynthesis ; Polyphenols ; pharmacology ; Punicaceae ; Rats ; Rats, Wistar ; Transforming Growth Factor beta1 ; physiology ; Vascular Endothelial Growth Factor A ; physiology ; Wound Healing ; drug effects

Glucose prevents the development of diabetes induced by alloxan. In the present study, the protective mechanism of glucose against alloxan-induced beta-cell damage was investigated using HIT-T 15 cell, a Syrian hamster transformed beta-cell line. Alloxan caused beta-cell damages with DNA fragmentation, inhibition of glucose-stimulated insulin release, and decrease of cellular ATP level, but all of these beta-cell damages by alloxan were prevented by the presence of 20 mM glucose. Oligomycin, a specific inhibitor of ATP synthase, completely abolished the protective effects of glucose against alloxan-induced cell damage. Furthermore, treatment of nuclei isolated from HIT-T15 cells with ATP significantly prevented the DNA fragmentation induced by Ca2+. The results indicate that ATP produced during glucose metabolism plays a pivotal role in the protection of glucose against alloxan-induced beta-cell damage.
Adenosine Triphosphate/pharmacology ; Adenosine Triphosphate/metabolism ; Alloxan/pharmacology* ; Animal ; B-Lymphocytes/metabolism ; B-Lymphocytes/drug effects* ; B-Lymphocytes/cytology ; Calcium/pharmacology ; Cell Line ; Cell Nucleus/genetics ; Cell Nucleus/drug effects ; Cell Survival ; DNA/metabolism ; DNA/genetics ; DNA/drug effects ; DNA Fragmentation ; Dose-Response Relationship, Drug ; Egtazic Acid/pharmacology ; Glucose/pharmacology* ; Insulin/secretion ; Oligomycins/pharmacology

Glucosamine, a naturally occurring amino monosaccharide, has been reported to play a role in the regulation of apoptosis more than half century. However the effect of glucosamine on tumor cells and the involved molecular mechanisms have not been thoroughly investigated. Glucosamine enters the hexosamine biosynthetic pathway (HBP) downstream of the rate-limiting step catalyzed by the GFAT (glutamine:fluctose-6-phosphate amidotransferase), providing UDP-GlcNAc substrates for O-linked beta-N-acetylglucosamine (O-GlcNAc) protein modification. Considering that O-GlcNAc modification of proteasome subunits inhibits its activity, we examined whether glucosamine induces growth inhibition via affecting proteasomal activity. In the present study, we found glucosamine inhibited proteasomal activity and the proliferation of ALVA41 prostate cancer cells. The inhibition of proteasomal activity results in the accumulation of ubiquitinated proteins, followed by induction of apoptosis. In addition, we demonstrated that glucosamine downregulated proteasome activator PA28gamma and overexpression of PA28gamma rescued the proteasomal activity and growth inhibition mediated by glucosamine. We further demonstrated that inhibition of O-GlcNAc abrogated PA28gamma suppression induced by glucosamine. These findings suggest that glucosamine may inhibit growth of ALVA41 cancer cells through downregulation of PA28gamma and inhibition of proteasomal activity via O-GlcNAc modification.
Acetylglucosamine/chemistry/metabolism ; Alloxan/pharmacology ; Apoptosis/*drug effects ; Autoantigens/genetics/*metabolism ; Cell Line, Tumor ; Cell Proliferation/*drug effects ; Gene Expression Regulation, Neoplastic ; Glucosamine/*pharmacology ; Humans ; Male ; Phosphorylation ; Prostatic Neoplasms/*enzymology ; Proteasome Endopeptidase Complex/*antagonists & inhibitors/genetics/metabolism ; RNA, Small Interfering/genetics ; Ubiquitinated Proteins/metabolism

An alpha-amylase inhibitor (alpha-AI) was isolated from white kidney beans (Phaseolus vulgaris L) by ethanol fractional precipitation, ion exchange chromatography and gel filtration column chromatography. It was a homogeneity glycoprotein demonstrated by SDS-PAGE and gel filtration on CL-6B. The glycoprotein contained 88.2% protein and was rich in aspartic acid, glutamic acid, leucine, threonine and serine. The carbohydrate moiety was consisted of Man, Glc, Gal and Xyl in a mole ratio of 2.42: 1.50: 1.52: 1.00. The glycan and the core protein backbone was connected by O-linkage as determined by beta-elimination reaction. The continuous oral administration of the alpha-AI (150 mg x kg(-1) x d(-1)) for 7 days can lower fasting blood glucose and 300 mg x kg(-1) x d(-1) alpha-AI for 7 days can improve the sugar tolerance on alloxan-dependent diabetic model rats. The result showed the alpha-AI obtained from white kidney beans had good hypoglycemic effect on alloxan induced diabetic rats and may have high potential pharmaceutical value as a regulative digestive-starch degradation in patients suffering from diabetes.
Alloxan ; Amino Acids ; analysis ; Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; chemically induced ; Female ; Glycoproteins ; chemistry ; isolation & purification ; pharmacology ; Molecular Weight ; Monosaccharides ; analysis ; Phaseolus ; chemistry ; Plant Lectins ; chemistry ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Rats ; Rats, Sprague-Dawley ; Vegetable Proteins ; analysis ; alpha-Amylases ; antagonists & inhibitors

To investigate the effects of 2-(4-methoxycarbonyl-2-tetradecyloxyphenyl)carbamoylbenzoic acid (CX09040) on protecting pancreatic β cells, the β cell dysfunction model mice were induced by injection of alloxan into the caudal vein of ICR mice, and were treated with compound CX09040. Liraglutide was used as the positive control drug. The amount and the size of islets observed in pathological sections were calculated to evaluate the β cell mass; the glucose stimulated insulin secretion (GSIS) test was applied to estimate the β cell secretary function; the oral glucose tolerance test (OGTT) was taken to observe the glucose metabolism in mice; the expressions of protein in pancreas were detected by Western blotting. The effects on the target protein tyrosine phosphatase 1B (PTP1B) were assessed by the PTP1B activities of both recombinant protein and the intracellular enzyme, and by the PTP1B expression in the pancreas of mice, separately. As the results, with the treatment of CX09040 in alloxan-induced β cell dysfunction mice, the islet amount (P<0.05) and size (P<0.05) increased significantly, the changes of serum insulin in GSIS (P<0.01) and the values of acute insulin response (AIR, P<0.01) were enhanced, compared to those in model group; the impaired glucose tolerance was also ameliorated by CX09040 with the decrease of the values of area under curve (AUC, P<0.01). The activation of the signaling pathways related to β cell proliferation was enhanced by increasing the levels of p-Akt/Akt (P<0.01), p-FoxO1/FoxOl (P<0.001) and PDX-1 (P<0.01). The effects of CX09040 on PTP1B were observed by inhibiting the recombinant hPTP1B activity with IC50 value of 2.78x 10(-7) mol.L-1, reducing the intracellular PTP1B activity of 72.8% (P<0.001), suppressing the PTP1B expression (P<0.001) and up-regulating p-IRβ/IRβ (P<0.01) in pancreas of the β cell dysfunction mice, separately. In conclusion, compound CX09040 showed significant protection effects against the dysfunction of β cell of mice by enlarging the pancreatic β cell mass and increasing the glucose-induced insulin secretion; its major mechanism may be the inhibition on target PTP1B and the succedent up-regulation of β cell proliferation.
Alloxan ; Animals ; Benzoates ; pharmacology ; Biological Assay ; Disease Models, Animal ; Glucose ; metabolism ; Glucose Tolerance Test ; Insulin ; secretion ; Insulin Resistance ; Insulin-Secreting Cells ; drug effects ; Liraglutide ; pharmacology ; Mice ; Mice, Inbred ICR ; Molecular Weight ; Pancreas ; drug effects ; enzymology ; Protein Tyrosine Phosphatase, Non-Receptor Type 1 ; antagonists & inhibitors ; Signal Transduction