OBJECTIVE: To investigate the intervention of curcumin and its analogue J7 on oxidative stress injury in testis of type 2 diabetic rats. METHODS: Sixty male SD rats, 10 rats were chosen as normal control group (NC), the other 50 rats were assigned to experiment group. Experiment diabetic rats were induced by high-fat food and intraperitoneal injection of steptozotocin (STZ). After the model was established successfully, diabetic rats were divided into four groups randomly: diabetes mellitus group (DM, n=12), curcumin treatment group (CUR, n=10), high dose treatment group of J7 (J+, n=10), low dose treatment group of J7 (J-, n=10). The CUR group were intragastrically administered with curcumin 20 mg/kg daily, in addition, the J+ group and the J- group were intragastrically administered with J7 20 mg/kg and 10 mg/kg daily respectively. After 8 weeks, the fast blood glucose was detected biochemically. The activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) were detected by hydroxylamine method and thiobarbituric acid method respectively. The protein expressions of the nuclear factor-erythroid 2-related factor 2 (tNrf2), phosphorylation of Nrf2 (pNrf2), catalase (CAT), NAD(P)H quinine oxidoreductase 1 (NQO1) were measured by Western blot. The mRNA expressions of CAT, NQO1, hemeoxygenase-1 (HO1) were measured by quantitative real-time PCR (qRT-PCR). Morphological structure of testis was observed by hematoxylin-eosin (HE) staining. The expressions of Nrf2 and CAT were also detected by immunohistochemical method. RESULTS: The levels of fast blood glucose and MDA in DM group were increased significantly(P＜0.05), while the body weight, the activity of SOD, the protein expressions of pNrf2/tNrf2, CAT, NQO1 and the mRNA expressions of CAT, NQO1, HO1 were decreased (P＜0.05). Under light microscope, the DM group showed disrupted histological appearance. Immunohistochemistry showed that the protein expressions of Nrf2 around the nucleus and CAT were decreased. With the treatment of curcumin and J7, the MDA levels in the three treatment groups were decreased (P＜0.05). The activity of SOD, the protein expressions of pNrf2/tNrf2, CAT, NQO1 and the mRNA expressions of NQO1, HO1 were increased (P＜0.05). the levels of fast blood glucose were decreased in the J+ and J- group (P＜0.05), and the mRNA expression of CAT was increased in the J+ group (P＜0.05). The ratio of pNrf2/tNrf2 in the J+ group was significantly higher than that in CUR and J- group (P＜0.05). The protein level of CAT in the J+ group was also significantly higher than that in J- group (P＜0.05). There were no significant differences in other indexes among the three treatment groups. Under light microscope, the morphology was obviously improved in the three treatment groups. Immunohistochemistry showed that the protein expressions of Nrf2 around the nucleus and CAT were increased in the three treatment groups. It was suggested that high dose J7 had better antioxidant stress ability in testis of diabetic rats. CONCLUSION Curcumin and J7 could inhibit the oxidative stress damage of testicular tissue in diabetic rats, which might be related with the activation of the Nrf2-ARE signaling pathway.
Animals ; Blood Glucose ; analysis ; Curcumin ; analogs & derivatives ; pharmacology ; Diabetes Mellitus, Experimental ; Diabetes Mellitus, Type 2 ; Male ; Malondialdehyde ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Oxidative Stress ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Superoxide Dismutase ; metabolism ; Testis ; drug effects ; pathology

High-fat diets affect male reproduction and sexual function. Therefore, we evaluated the effects of prolonged resveratrol administration on the metabolic, sperm, and testicular parameters of rats fed a cafeteria diet. Male Wistar rats were divided at weaning into control (C, n = 20) and cafeteria (CAF, n = 16) groups. At 3 months, half of them were given daily supplementations of resveratrol (C-R, n = 10; CAF-R, n = 8) at a dosage of 30 mg kg^-1 body mass for 2 months. Animals were killed at 5 months of age, and blood, spermatozoa, and testes were collected for further analysis. Data were analyzed by one-way ANOVA, and P < 0.05 was considered statistically significant. The CAF diet promoted hyperglycemia (P < 0.0001), and treatment with resveratrol reversed this condition (P < 0.0001). The CAF diet reduced sperm viability and motility, while resveratrol improved these parameters (P < 0.05). Regarding testicular morphology, the height of the seminiferous epithelium was reduced in the CAF group compared with that of the C group (P = 0.0007). Spermatogenic cell proliferation was also reduced in the CAF group compared with that of the C group. However, the CAF-R showed an increase in cell proliferation rate compared with that of the untreated CAF group (P = 0.0024). Although it did not modify body mass, the consumption of a CAF diet promoted hyperglycemia, adverse testicular morphology remodeling, and abnormal sperm, which were attenuated by treatment with resveratrol, thus suggesting a protective effect of this antioxidant on spermatogenesis.
Animals ; Antioxidants/therapeutic use* ; Blood Glucose ; Cell Proliferation/drug effects* ; Diet, High-Fat ; Hyperglycemia/metabolism* ; Lipids/blood* ; Male ; Rats ; Rats, Wistar ; Resveratrol/therapeutic use* ; Sperm Motility/drug effects* ; Spermatozoa/metabolism* ; Testis/metabolism*

OBJECTIVE: The present study aims at determining the stability of a popular type 2 diabetes rat model induced by a high-fat diet combined with a low-dose streptozotocin injection. METHODS: Wistar rats were fed with a high-fat diet for 8 weeks followed by a one-time injection of 25 or 35 mg/kg streptozotocin to induce type 2 diabetes. Then the diabetic rats were fed with regular diet/high-fat diet for 4 weeks. Changes in biochemical parameters were monitored during the 4 weeks. RESULTS: All the rats developed more severe dyslipidemia and hepatic dysfunction after streptozotocin injection. The features of 35 mg/kg streptozotocin rats more resembled type 1 diabetes with decreased body weight and blood insulin. Rats with 25 mg/kg streptozotocin followed by normal diet feeding showed normalized blood glucose level and pancreatic structure, indicating that normal diet might help recovery from certain symptoms of type 2 diabetes. In comparison, diabetic rats fed with high-fat diet presented decreased but relatively stable blood glucose level, and this was significantly higher than that of the control group (P<0.05). CONCLUSIONS This model easily recovers with normal diet feeding. A high-fat diet is suggested as the background diet in future pharmacological studies using this model.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; etiology ; physiopathology ; Diabetes Mellitus, Type 2 ; blood ; etiology ; physiopathology ; Diet, High-Fat ; adverse effects ; Insulin ; blood ; Lipids ; blood ; Liver ; drug effects ; pathology ; physiopathology ; Male ; Malondialdehyde ; blood ; Oxidative Stress ; Rats ; Rats, Wistar ; Streptozocin ; administration & dosage ; toxicity ; Superoxide Dismutase ; blood ; Uric Acid ; blood

This study aimed to investigate the antihypertensive effect and possible mechanism of Dendrobium officinale flos on hypertensive rats induced by high glucose and high fat compound alcohol. The hypertensive models were successfully made by high-glucose and high-fat diet, with gradient drinking for 4 weeks, and then divided into model control group, valsartan (5.7 mg·kg⁻¹) positive control group and D. officinale flos groups (3，1 g·kg⁻¹). After 6 weeks of treatment, the blood pressure of rats was measured regularly. After the last administration, endothelin-1 (ET-1), thromboxane B₂ (TXB₂), prostacyclin (PGI₂) and nitric oxide (NO) were tested. Endothelial nitric oxide synthase (eNOS) expression and lesion status in thoracic aorta were detected. The vascular endothelium dependent dilation of the thoracic aorta was detected by the isolated vascular loop tension test. The results showed that D. officinale flos could significantly reduce systolic blood pressure and mean arterial pressure in hypertensive rats, inhibit the thickening of thoracic aorta and the loss of endothelial cells, reduce plasma content of ET-1 and TXB₂, and increase the content of PGI₂ and NO. After long-term administration, vascular endothelium dependent dilation of the thoracic aorta was significantly increased, and could be blocked by the eNOS inhibitor (L-NAME) and increase the expression of eNOS. Therefore, D. officinale flos has an obvious antihypertensive effect on high glucose and high fat compound alcohol-induced hypertensive rats. Its mechanism may be correlated with the improvement of vascular diastolic function by protecting vascular endothelial cells, and finally resist hypertension.
Animals ; Antihypertensive Agents ; pharmacology ; Blood Pressure ; Dendrobium ; chemistry ; Diet, High-Fat ; Drugs, Chinese Herbal ; pharmacology ; Endothelin-1 ; blood ; Endothelium, Vascular ; drug effects ; Epoprostenol ; blood ; Glucose ; Hypertension ; chemically induced ; drug therapy ; Nitric Oxide ; blood ; Nitric Oxide Synthase Type III ; metabolism ; Rats ; T-Box Domain Proteins ; blood ; Vasodilation

Catalpol, a major bioactive component from Rehmannia glutinosa, which has been used to treat diabetes. The present study was designed to elucidate the anti-diabetic effect and mechanism of action for catalpol in db/db mice. The db/db mice were randomly divided into six groups (10/group) according to their blood glucose levels: db/db control, metformin (positive control), and four dose levels of catalpol treatment (25, 50, 100, and 200 mg·kg), and 10 db/m mice were used as the normal control. All the groups were administered orally for 8 weeks. The levels of fasting blood glucose (FBG), random blood glucose (RBG), glucose tolerance, insulin tolerance, and glycated serum protein (GSP) and the globe gene expression in liver tissues were analyzed. Our results showed that catalpol treatment obviously reduced water intake and food intake in a dose-dependent manner. Catalpol treatment also remarkably reduce fasting blood glucose (FBG) and random blood glucose (RBG) in a dose-dependent manner. The RBG-lowering effect of catalpol was better than that of metformin. Furthermore, catalpol significantly improved glucose tolerance and insulin tolerance via increasing insulin sensitivity. Catalpol treatment significantly decreased GSP level. The comparisons of gene expression in liver tissues among normal control mice, db/db mice and catalpol treated mice (200 and 100 mg·kg) indicated that there were significant increases in the expressions of 287 genes, whichwere mainly involved in lipid metabolism, response to stress, energy metabolism, and cellular processes, and significant decreases in the expressions of 520 genes, which were mainly involved in cell growth, death, immune system, and response to stress. Four genes expressed differentially were linked to glucose metabolism or insulin signaling pathways, including Irs1 (insulin receptor substrate 1), Idh2 (isocitrate dehydrogenase 2 (NADP), mitochondrial), G6pd2 (glucose-6-phosphate dehydrogenase 2), and SOCS3 (suppressor of cytokine signaling 3). In conclusion, catalpol ecerted significant hypoglycemic effect and remarkable therapeutic effect in db/db mice via modulating various gene expressions.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; genetics ; metabolism ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; analysis ; Gene Expression ; drug effects ; Glucosephosphate Dehydrogenase ; genetics ; metabolism ; Humans ; Hypoglycemic Agents ; administration & dosage ; Insulin ; metabolism ; Insulin Receptor Substrate Proteins ; genetics ; metabolism ; Iridoid Glucosides ; administration & dosage ; analysis ; Isocitrate Dehydrogenase ; genetics ; metabolism ; Liver ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Rehmannia ; chemistry ; Suppressor of Cytokine Signaling 3 Protein ; genetics ; metabolism

Diabetic nephropathy (DN) is one of the common microvascular complications of diabetes mellitus. Renal fibrosis is closely related to the deterioration of renal function. The present study aimed to investigate protective effect of Taxus chinensis on high-fat diet/streptozotocin-induced DN in rats and explore the underlying mechanism of action. The rat DN model was established via feeding high fat diet for 4 weeks and subsequently injecting streptozotocin (30 mg·kg body weight) intraperitoneally. The rats with blood glucose levels higher than 16.8 mmol·L were selected for experiments. The DN rats were treated with Taxus chinensis orally (0.32, 0.64, and 1.28 g·kg) once a day for 8 weeks. Taxus chinensis significantly improved the renal damage, which was indicated by the decreases in 24-h urinary albumin excretion rate, blood serum creatinine, and blood urea nitrogen. Histopathological examination confirmed the protective effect of Taxus chinensis. The thickness of glomerular basement membrane was reduced, and proliferation of mesangial cells and podocytes cells and increase in mesangial matrix were attenuated. Further experiments showed that Taxus chinensis treatment down-regulated the expression of TGF-β1 and α-SMA, inhibited phosphorylation of Smad2 and Smad3. These results demonstrated that Taxus chinensis alleviated renal injuries in DN rats, which may be associated with suppressing TGF-β1/Smad signaling pathway.
Albumins ; Animals ; Blood Glucose ; metabolism ; Creatinine ; blood ; Diabetic Nephropathies ; blood ; drug therapy ; genetics ; urine ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Kidney ; drug effects ; metabolism ; Male ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; Smad Proteins ; genetics ; metabolism ; Taxus ; chemistry ; Transforming Growth Factor beta1 ; metabolism

Xiao Ke Qing (XKQ) granule has been clinically used to treat type 2 diabetes mellitus (T2DM) for 10 years in Chinese traditional medication. However, its mechanisms against hyperglycemia remain poorly understood. This study aims to investigate XKQ mechanisms on diabetes and diabetic liver disease by using the KKAy mice model. Our results indicate that XKQ can significantly reduce food and water intake. XKQ treatment also remarkably decreases both the fasting blood glucose and blood glucose in the oral glucose tolerance test. Additionally, XKQ can significantly decrease the serum alanine aminotransferase level and liver index and can alleviate the fat degeneration in liver tissues. Moreover, XKQ can ameliorate insulin resistance and upregulate the expression of IRS-1, PI3K (p85), p-Akt, and GLUT4 in the skeletal muscle of KKAy mice. XKQ is an effective drug for T2DM by ameliorating insulin resistance and regulating the PI3K/Akt signaling pathway in the skeletal muscle.
Animals ; Blood Glucose ; drug effects ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Female ; Glucose Tolerance Test ; Glucose Transporter Type 4 ; metabolism ; Hypoglycemic Agents ; pharmacology ; Insulin ; blood ; Insulin Resistance ; Liver ; drug effects ; pathology ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects

Diabetes is a widespread, rapidly increasing metabolic disease that is driven by hyperglycemia. Early glycemic control is of primary importance to avoid vascular complications including development of retinal disorders leading to blindness, end-stage renal disease, and accelerated atherosclerosis with a higher risk of myocardial infarction, stroke and limb amputations. Even after hyperglycemia has been brought under control, "metabolic memory," a cluster of irreversible metabolic changes that allow diabetes to progress, may persist depending on the duration of hyperglycemia. Manipulation of bile acid (BA) receptors and the BA pool have been shown to be useful in establishing glycemic control in diabetes due to their ability to regulate energy metabolism by binding and activating nuclear transcription factors such as farnesoid X receptor (FXR) in liver and intestine as well as the G-protein coupled receptor, TGR5, in enteroendocrine cells and pancreatic β-cells. The downstream targets of BA activated FXR, FGF15/21, are also important for glucose/insulin homeostasis. In this review we will discuss the effect of BAs on glucose and lipid metabolism and explore recent research on establishing glycemic control in diabetes through the manipulation of BAs and their receptors in the liver, intestine and pancreas, alteration of the enterohepatic circulation, bariatric surgery and alignment of circadian rhythms.
Animals ; Bile Acids and Salts ; blood ; metabolism ; Blood Glucose ; drug effects ; metabolism ; Circadian Rhythm ; Diabetes Mellitus ; blood ; drug therapy ; metabolism ; Energy Metabolism ; Homeostasis ; Humans ; Hyperglycemia ; metabolism ; physiopathology ; Hypoglycemic Agents ; therapeutic use ; Intestinal Mucosa ; metabolism ; Intestines ; drug effects ; Lipid Metabolism ; Liver ; drug effects ; metabolism ; Receptors, Cytoplasmic and Nuclear ; metabolism ; Receptors, G-Protein-Coupled ; metabolism ; Signal Transduction

Objective To assess the efficiency and safety of a novel sodium-glucose co-transporter 2 (SGLT2) inhibitor-SGLT2 inhibitors, in combination with insulin for type 1 diabetes mellitus (T1DM). Methods We searched Medline, Embase, and the Cochrane Collaboration Library to identify the eligible studies published between January 2010 and July 2016 without restriction of language. The Food and Drug Administration (FDA) data and ClinicalTrials (http://www.clinicaltrials.gov) were also searched. The included studies met the following criteria: randomized controlled trials; T1DM patients aged between 18 and 65 years old; patients were treated with insulin plus SGLT2 inhibitors for more than 2 weeks; patients' glycosylated hemoglobin (HbA1c) levels were between 7% and 12%. The SGLT2 inhibitors group was treated with SGLT2 inhibitors plus insulin, and the placebo group received placebo plus insulin treatment. The outcomes should include one of the following items: fasting blood glucose, HbA1c, glycosuria, or adverse effects. Data were analyzed by two physicians independently. The risk of bias was evaluated by using the Cochrane Collaboration's Risk of Bias tool and heterogeneity among studies was assessed using Chi-square test. Random effect model was used to analyze the treatment effects with Revman 5.3.Results Three trials including 178 patients were enrolled. As compared to the placebo group, SGLT2 inhibitor absolutely decreased fasting blood glucose [mean differences (MD) -2.47 mmol/L, 95% confidence interval (CI) -3.65 to -1.28, P<0.001] and insulin dosage (standardized MD -0.75 U, 95%CI -1.17 to -0.33, P<0.001). SGLT2 inhibitors could also increase the excretion of urine glucose (MD 131.09 g/24 h, 95%CI 91.79 to 170.39, P<0.001). There were no significant differences in the incidences of hyperglycemia [odds ratio (OR) 1.82, 95%CI 0.63 to 5.29, P=0.27], urinary tract infection (OR 0.95, 95%CI 0.19 to 4.85, P=0.95), genital tract infection (OR 0.27, 95%CI 0.01 to 7.19, P=0.43), and diabetic ketoacidosis (OR 6.03, 95%CI 0.27 to 135.99, P=0.26) between the two groups.Conclusion SGLT2 inhibitors combined with insulin might be an efficient and safe treatment modality for T1DM patients.
Adolescent ; Adult ; Aged ; Blood Glucose ; metabolism ; Diabetes Mellitus, Type 1 ; blood ; drug therapy ; Drug Therapy, Combination ; methods ; Fasting ; blood ; Female ; Glycated Hemoglobin A ; metabolism ; Humans ; Hypoglycemic Agents ; adverse effects ; therapeutic use ; Insulin ; adverse effects ; therapeutic use ; Male ; Middle Aged ; Randomized Controlled Trials as Topic ; Sodium-Glucose Transporter 2 ; antagonists & inhibitors

The present study was designed to explore the mechanism by which ethanol extract of Bombax ceiba leaves (BCE) and its main constituent mangiferin (MGF) affect diabetic nephropathy by combating oxidative stress. Oral administration of BCE and MGF to normal and streptozotocin (STZ)-induced diabetic mice were carried out. Fasting blood glucose, 24-h urinary albumin, serum creatinine, and blood urea nitrogen were tested, histopathology, and immunohistochemical analysis of kidney tissues were performed. Moreover, mesangial cells were treated with BCE and MGF for 48 h with or without 25 mmol·L of glucose. Immunofluorescence, Western blot and apoptosis analyses were used to investigate their regulation of oxidative stress and mitochondrial function. BCE and MGF ameliorated biochemical parameters and restored STZ-induced renal injury in the model mice. In vitro study showed that high glucose stimulation increased oxidative stress and cell apoptosis in mesangial cells. BCE and MGF limited mitochondrial membrane potential (Δψm) collapse by inhibiting Nox4, mitochondrially bound hexokinase II dissociation, and subsequent ROS production, which effectively reduced oxidative stress, cleaved caspase-3 expression and cell apoptosis. Our work indicated that BCE and MGF had protective effects on diabetic caused kidney injury and prevented oxidative stress in mesangial cells by regulation of hexokinase II binding and Nox4 oxidase signaling.
Animals ; Blood Glucose ; metabolism ; Bombax ; chemistry ; Caspase 3 ; genetics ; metabolism ; Diabetic Nephropathies ; drug therapy ; genetics ; metabolism ; Humans ; Male ; Mice ; Oxidative Stress ; drug effects ; Plant Extracts ; administration & dosage ; Plant Leaves ; chemistry ; Xanthones ; administration & dosage