Tu-Xian decoction (TXD), a traditional Chinese medicine (TCM) formula, has been frequently administered to manage diabetic cognitive impairment (DCI). Despite its widespread use, the mechanisms underlying TXD's protective effects on DCI have yet to be fully elucidated. As a significant regulator in neurodegenerative conditions, death-associated protein kinase-1 (DAPK-1) serves as a focus for understanding the action of TXD. This study was designed to whether TXD mediates its beneficial outcomes by inhibiting DAPK-1. To this end, a diabetic model was established using Sprague-Dawley (SD) rats through a high-fat, high-sugar (HFHS) diet regimen, followed by streptozotocin (STZ) injection. The experimental cohort was stratified into six groups: Control, Diabetic, TC-DAPK6, high-dose TXD, medium-dose TXD, and low-dose TXD groups. Following a 12-week treatment period, various assessments-including blood glucose levels, body weight measurements, Morris water maze (MWM) testing for cognitive function, brain magnetic resonance imaging (MRI), and histological analyses using hematoxylin-eosin (H&E), and Nissl staining-were conducted. Protein expression in the hippocampus was quantified through Western blotting analysis. The results revealed that TXD significantly improved spatial learning and memory abilities, and preserved hippocampal structure in diabetic rats. Importantly, TXD administration led to a down-regulation of proteins indicative of neurological damage and suppressed DAPK-1 activity within the hippocampal region. These results underscore TXD's potential in mitigating DCIvia DAPK-1 inhibition, positioning it as a viable therapeutic candidate for addressing this condition. Further investigation into TXD's molecular mechanisms may elucidate new pathways for the treatment of DCI.
Animals ; Rats ; Brain/metabolism* ; Cognitive Dysfunction/drug therapy* ; Diabetes Mellitus, Experimental/metabolism* ; Hippocampus ; Rats, Sprague-Dawley

OBJECTIVETo study effects of insulin treatment on intracellular lipid content in livers and insulin resistance of type 2 diabetic rats.

METHODSType 2 diabetic rats were induced by injecting streptozotocin (25 mg/kg) and fat rich food. Then according to the results of the oral glucose tolerance test (OGTT) and glucose-induced insulin secretion test (IST), the rats were divided into two groups: control group (DC) and insulin treated group (DI). Normal rats (NC) served as controls. The treatment of each group with either NPH insulin (4 approximately 6 U . kg-1. d-1), or saline continued for 4 weeks. Body weight, OGTT, IST, blood lipids, intracellular lipids in liver and liver histology were studied. The insulin sensitivity index (ISI) was applied to assess the status of insulin resistance.

RESULTSBlood lipid and intracellular lipids in livers in the DC were higher than those in NC (t = 2.59 approximately 15.77, P < 0.05) and the ISI was lower (t = 3.16, P < 0.05), with many fatty droplets appearing in the livers. In comparison to DC, DI showed that blood lipids were decreased, but lipids in livers were markedly increased (TG, TC, FFA increased 55.7%, 19.87%, 22.2%, respectively), and fatty droplets in hepatocytes were larger, but the ISI did not change significantly.

CONCLUSIONInsulin treatment can make blood glucose normal, increase the intracellular lipid content in the liver, and not increase the insulin resistance significantly.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Insulin ; therapeutic use ; Insulin Resistance ; Lipid Metabolism ; Liver ; metabolism ; Male ; Rats ; Rats, Wistar

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus, which is characterized in renal tubulointerstitial fibrosis (TIF). The current study was designed to investigate the protective effect of Jujuboside A (Ju A) on TIF in type 2 diabetes (T2DM) mice, and explore its underlying anti-fibrosis mechanism. A mouse T2DM model was established using high fat diet (HFD) feeding combined with intraperitoneal injection of streptozotocin (STZ). Then, diabetic mice were treated with Ju A (10, 20 and 40 mg·kg^-1·d^-1, i.g.) for 12 weeks. Results showed that administration of Ju A not only down-regulated fasting blood glucose (FBG) levels, but also improved hyperlipidemia and renal function in diabetic mice. Moreover, the reduced ECM accumulation was observed in the renal cortex of Ju A treated diabetic mice, while the TIF progression was also attenuated by Ju A through blocking the epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs). Further mechanism studies showed that Ju A treatment effectively down-regulated the protein expression and subsequent nuclear translocation of Yin Yang 1 (YY1) in the renal cortex of diabetic mice, and reduced the levels of transforming growth factor-β1 (TGF-β1) in the serum and renal cortex of Ju A treated mice. According to invitro studies, the up-regulated YY1/TGF-β1 signaling pathway was restored by Ju A in high glucose (HG) cultured HK-2 cells. Taken together, these findings demonstrated that Ju A can ameliorate the TIF of DN through down-regulating the YY1/TGF-β1 signaling pathway.
Animals ; Blood Glucose ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Type 2/drug therapy* ; Diabetic Nephropathies/metabolism* ; Fibrosis ; Mice ; Saponins ; Signal Transduction ; Streptozocin ; Transforming Growth Factor beta1/metabolism*

OBJECTIVETo observe the effects of Ganoderma lucidum spores on Cytochrome C (Cyt-C) and mitochondrial calcium in the testis of NIDDM rats.

METHODSFifty male Wistar rats were divided randomly into three groups: model, ganoderma and normal control, the first two groups injected with 2% STZ through vena caudalis, and the last one with half-and-half sodium citrate/citrate buffer solution. Two weeks after normal diet, glucose tolerance tests were performed and the rats with abnormal glucose tolerance from the model and ganoderma groups received high-fat and high-carbohydrate food, the ganoderma group given Ganoderma lucidum spores (250mg/[ kg x d] ) in addition, both for 10 weeks. Glucose tolerance tests were repeated 1 day before the end of the experiment and the rats were castrated and relevant indexes measured.

RESULTSThe NIDDM model was successfully constructed. In the model group, the levels of mitochondrial Cyt-C and mitochondrial calcium were significantly lower (P <0. 05) while that of the plasma Cyt-C was significantly higher than in the ganoderma and the control groups.

CONCLUSIONCyt-C and calcium ion are involved in the damage of the testis. Ganoderma lucidum spores can protect the testis of NIDDM rats.

Animals ; Calcium ; metabolism ; Cytochromes c ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetes Mellitus, Type 2 ; drug therapy ; Male ; Mitochondria ; drug effects ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Reishi ; Testis ; drug effects ; metabolism

This study focused on the ameliorative effects of gypenosides(GPS) on insulin sensitivity and inflammatory factors in rats with type 2 diabetes mellitus(T2 DM) and explored their possible molecular mechanisms. After the successful establishment of T2 DM model, diabetic rats were randomly divided into four groups, including model group, GPS groups(200, 100 mg·kg~(-1)) and metformin group(100 mg·kg~(-1)), with healthy rats serving as the control. After 6-week intragastric administration, fasting blood glucose(FBG) and oral glucose tolerance were examined. The levels of insulin, C-peptide, tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6) and C-reactive protein(CRP) in serum were examined. Then the homeostasis model assessment of insulin resistance(HOMA-IR) and insulin sensitivity index(ISI) were calculated. The protein expression levels of phosphorylated insulin receptor substrate-1(p-IRS-1) and phosphorylated protein kinase B(p-Akt) in skeletal muscle were measured by Western blot, as well as those of phosphorylated inhibitor of nuclear factor-κB(NF-κB) kinase β(p-IKKβ), phosphorylated alpha inhibitor of NF-κB(p-IκBα) and phosphorylated p65 subunit of NF-κB(p-p65) in adipose tissue. The relative expression levels of glucose transporter 4(GLUT4) mRNA in skeletal muscle and NF-κB mRNA in adipose tissue were measured by qRT-PCR, and the morphological changes of pancreatic tissue were observed. Compared with the model group, the GPS groups witnessed significant decrease in FBG, marked amelioration of impaired oral glucose tolerance and significant increase in ISI. Further, the high-dose GPS group saw significantly reduced HOMA-IR, TNF-α, IL-1β and CRP, significantly increased expression levels of p-IRS-1(Tyr), p-Akt and GLUT4, and markedly inhibited p-IRS-1(Ser), p-IKKβ, p-IκBα, p-p65 and NF-κB. The concentration of CRP and the expression levels of p-IRS-1(Ser), p-IKKβ, p-IκBα and NF-κB were remarkably reduced in the low-dose GPS group. However, GPS was found less effective in the regulation of serum insulin, C-peptide and IL-6 levels and the alleviation of pancreatic islet injury. The results indicated that GPS can reduce FBG and improve insulin sensitivity in diabetic rats possibly by regulating the NF-κB signaling pathway, inhibiting inflammation, and thereby regulating the expression of key proteins in the insulin signaling pathway.
Animals ; Diabetes Mellitus, Experimental/drug therapy* ; Diabetes Mellitus, Type 2/genetics* ; Gynostemma ; Insulin ; Insulin Resistance ; NF-kappa B/metabolism* ; Plant Extracts ; Rats ; Signal Transduction

The dry root and rhizome of Panax ginseng C. A. Mey has garnered much interest owing to its medicinal properties against diabetes and cardiovascular diseases. In this study, an ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS)-based metabolomics approach was used to illustrate the therapeutic mechanisms of ginseng extract on the serum and urinary metabolic profiles in streptozotocin-induced type 1 diabetes mellitus (T1DM) rats. Pharmacological and renal parameters in response to the administration of ginseng were also evaluated. In total, 16 serum endogenous metabolites and 14 urine endogenous metabolites, including pyruvic acid, indoleacetic acid, and phenylacetylglycine, were identified as potential biomarkers for diabetes. Pathway enrichment and network analysis revealed that the biomarkers modulated by ginseng were primarily involved in phenylalanine and pyruvate metabolism, as well as in arginine biosynthesis. Moreover, the levels of several renal injury-related biomarkers in T1DM rats were significantly restored following treatment with ginseng. The administration of the extract helped maintain tissue structure integrity and ameliorated renal injury. The findings suggest that the regulatory effect of ginseng extract on T1DM involves metabolic management of diabetic rats, which subsequently attenuates T1DM-induced early renal dysfunction.
Animals ; Biomarkers ; Chromatography, High Pressure Liquid/methods* ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Type 1/drug therapy* ; Kidney ; Metabolomics/methods* ; Panax/chemistry* ; Plant Extracts/pharmacology* ; Rats

OBJECTIVETo investigate the changes of xanthine oxidase (XOD), myeloperoxidase (MPO) and mitochondrial succinate dehydrogenase (SDH) in the testis and the protective effect of ganoderma lucidum spores on the testicular tissue of rats with non-insu- lin-dependent diabetes mellitus (NIDDM).

METHODSFifty male Wistar rats were divided randomly into a model, a ganoderma and a normal control group, the first two groups injected with 2% STZ (25 mg/kg) through the peritoneum, and the last one with half-and-half sodium citrate/citrate buffer solution. Two weeks after normal diet, glucose tolerance tests were performed and the rats with abnormal glucose tolerance in the model and ganoderma groups received high-fat and high-carbohydrate food, the latter given ganoderma lycium spores (250 mg/kg x d) in addition, both for 10 weeks and all rats fed alone. Glucose tolerance tests were repeated 1 day before the end of the experiment and the testes of the rats were harvested for the determination of XOD, MPO and SDH.

RESULTSSDH was significantly lower (P < 0.05) while XOD and MPO significantly higher in the model group than in the ganoderma and control groups (P < 0.05). The model rats exhibited abnormal convoluted seminiferous tubules, indistinct parietal layers, decreased or abolished gonepoiesis, luminal peripheral fibrous tissue (interstitial substance) accrementition, basal lamina thickening, and vessel wall fibrous tissue accrementition and sclerosis.

CONCLUSIONGanoderma lucidum spores can protect the testis of diabetic rats by reducing free radical-induced damage to the testicular tissue and enhancing the activity of SDH.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Male ; Peroxidase ; metabolism ; Rats ; Rats, Wistar ; Reishi ; Spores, Fungal ; Succinate Dehydrogenase ; metabolism ; Testis ; metabolism ; Xanthine Oxidase ; metabolism

Heart disease is one of the major cause of death in diabetic patients, but the thogenesis of diabetic cardio-myopathy remains unclear. In this experiment, to sess the significance of G protein signaling pathways in the pathogenesis of abetic cardiomyopathy, we analyzed the expression of G proteins and the tivities of second messenger dependent protein kinases: cAMP-dependent protein nase (PKA), DAG-mediated protein kinase C (PKC), and calmodulin dependent otein kinase II (CaM kinase II) in the streptozotocin induced diabetic rat art. The expression of Galphaq was increased by slightly over 10% (P<0.05) in abetic rat heart, while Galphas, Galphai, and Gbeta remained unchanged. The A activity in the heart did not change significantly but increased by 27%<0.01) in the liver. Insulin treatment did not restore the increased activity the liver. Total PKC activity in the heart was increased by 56% (P<0.01), and sulin treatment did not restore such increase. The CaM kinase II activity in e heart remained at the same level but was slightly increased in the liver 4% increase, P<0.05). These findings of increased expression of Galphaq in the reptozotocin-diabetic rat heart that are reflected by the increased level of C activity and insensitivity to insulin demonstrate that alteration of Galphaq y underlie, at least partly, the cardiac dysfunction that is associated with abetes. Copyright 2000 Academic Press.
Animal ; Ca(2+)-Calmodulin Dependent Protein Kinase/metabolism ; Cyclic AMP-Dependent Protein Kinases/metabolism ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Experimental/drug therapy ; Diabetes Mellitus, Experimental/chemically induced ; GTP-Binding Proteins/metabolism* ; Insulin/pharmacology ; Liver/metabolism ; Liver/drug effects ; Male ; Myocardium/metabolism* ; Protein Kinase C/metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Streptozocin

BACKGROUNDInsulin treatment plays a key role in management of diabetes mellitus. Clinical researches showed that extra improvements in restoration of insulin secretion of pancreatic beta cells were found in patients with newly diagnosed type 2 diabetes. The purpose of this study was to investigate the effects of early insulin treatment on insulin mRNA expression and morphological alterations of beta cells in a Sprague Dawley (SD) rat model of type 2 diabetes.

METHODSA rat model of type 2 diabetes mellitus (T2DM) was induced by a high fat diet (high energy, HE) and low doses of streptozotoxin (STZ, 40 mg/kg). A group of diabetic rats was then injected with protamine zinc insulin [PZI, 1 - 2 U x kg(-1) x d(-1)] for one week. Insulin mRNA expression, morphological features of pancreatic islets, and metabolic parameters were examined in rats using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and other techniques.

RESULTSIn insulin-treated diabetic rats, insulin mRNA levels prominently increased by 81.3% (P < 0.05), as compared with untreated diabetic rats. Moreover, timely insulin treatment noticeably improved the insulin content of beta cells, with an increase of 10.2% (P < 0.05), despite a slight reduction in fasting blood glucose (FBG), triglyceride (TG), and free fatty acid (FFA) levels, as compared to an untreated diabetic group.

CONCLUSIONInsulin treatment at the onset of T2DM effectively improves insulin synthesis, as confirmed by morphological changes to beta cells in a rat model of type 2 diabetes.

Adipose Tissue ; metabolism ; Animals ; Body Weight ; drug effects ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Insulin ; administration & dosage ; analysis ; genetics ; Islets of Langerhans ; drug effects ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Streptozocin

OBJECTIVETo observe the effect of compound Puerarin on collagen IV of streptozotocin-induced diabetic rats.

METHODSDiabetic nephropathy rats were induced by intraperitoneal injection of streptozotocin (STZ). Rats were allocated randomly to control group (10), diabetes model group (10), Vitamin C group (10), Puerarin group (10), vitamin C plus Puerarin group (10). The study period lasted for 12 weeks. During and after the treatment, the general state, blood glucose levels, glycosylated hemoglobin, blood urea nitrogen, serum collagen IV, blood urea nitrogen, serum creatinine, urinary albumin excretion rate of the 24-hour, and clearance rate of creatinine collagen IV protein were determined by immunohistochemistoche analysis as well as type the gene expression of collagen IV alpha 1 mRNA were determined by in situ hybridization analysis in the kidney tissue of different groups.

RESULTS(1) Diabetes mellitus and renal function lesion occurred in the four groups. (2) Vitamin C and Puerarin could improve the general conditions of diabetic Rats, decrease blood urea nitrogen [(8.68 +/- 0.43), (7.98 +/- 0.47) and (5.76 +/- 0.82) micromol/L, serum creatinine [(74.68 +/- 8.20), (75.52 +/- 7.98) and (58.66 +/- 6.65) mmol/L], and urinary albumin excretion rate of the 24-hour [(18.40 +/- 0.37), (17.24 +/- 0.30) and (9.97 +/- 1.27) mg/24 h x 10(-3)]; increase clearance rate of creatinine [(0.59 +/- 0.21), (0.61 +/- 0.14) and (0.69 +/- 0.32) ml/min], the expression of collage IV absorbance [(111.56 +/- 14.61), (110.78 +/- 9.69) and (95.44 +/- 9.97) ] in the diabetic Rats were significantly inhibited at the same time.

CONCLUSIONThe compound Puerarin might have some functions on preventing ren by inhibiting expression of type IV collagen.

Animals ; Collagen Type IV ; antagonists & inhibitors ; biosynthesis ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetic Nephropathies ; drug therapy ; metabolism ; Isoflavones ; pharmacology ; therapeutic use ; Male ; Phytotherapy ; Rats ; Rats, Sprague-Dawley