Teucrium polium L. Improves Blood Glucose and Lipids and Ameliorates Oxidative Stress in Heart and Aorta of Diabetic Rats.
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SUBMITTER: Zabihi NA
PROVIDER: S-EPMC6326021 | biostudies-other | 2018
REPOSITORIES: biostudies-other
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Project description:ObjectiveEndothelial dysfunction plays a pivotal role in the development of diabetic cardiovascular complications. Accumulation of endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) and inhibition of dimethylarginine dimethylaminohydrolase (DDAH) activity have been involved in diabetic endothelial dysfunction. This study was to investigate the effect of pyrrolidine dithiocarbamate (PDTC) on impairment of endothelium-dependent vasodilatation in diabetic rats and its potential mechanism.MethodsDiabetic rats were induced by a single intraperitoneal injection of streptozotocin (60mg/kg), and PDTC (10mg/kg) was given in drinking water for 8 weeks. Blood glucose and serum ADMA concentrations were measured in experimental rats. Recombinant adenovirus encoding human DDAH2 gene were constructed and ex vivo transferred to isolated rat aortas. The maximal relaxation (Emax) and half maximal effective concentration (EC50) of aortic rings response to accumulative concentrations of acetylcholine and vascular DDAH activity were examined before and after gene transfection.ResultsDiabetic rats displayed significant elevations of blood glucose and serum ADMA levels compared to control group (P<0.01). Vascular DDAH activity and endothelium-dependent relaxation of aortas were inhibited, as expressed by the decreased Emax and increased EC50 in diabetic rats compared to control rats (P<0.01). Treatment with PDTC not only decreased blood glucose and serum ADMA concentration (P<0.01) but also restored vascular DDAH activity and endothelium-dependent relaxation, evidenced by the higher Emax and lower EC50 in PDTC-treated diabetic rats compared to untreated diabetic rats (P<0.01). Similar restoration of Emax, EC50 and DDAH activity were observed in diabetic aortas after DDAH2-gene transfection.ConclusionsThese results indicate that PDTC could ameliorate impairment of endothelium-dependent relaxation in diabetic rats. The underlying mechanisms might be related to preservation of vascular DDAH activity and consequent reduction of endogenous ADMA in endothelium via its antioxidant action. This study highlights the therapeutic potential of PDTC in impaired vasodilation and provides a new strategy for treatment of diabetic cardiovascular complications.
| S-EPMC5513417 | biostudies-literature
Project description:Simvastatin is a lipid-lowering agent used to treat hypercholesterolemia and to reduce the risk of heart disease. This study scrutinized the beneficial effects of simvastatin on experimental diabetic cardiomyopathy (DCM), pointing to the role of hyperglycemia-induced oxidative stress and inflammation. Diabetes was induced by intraperitoneal injection of streptozotocin and both control and diabetic rats received simvastatin for 90 days. Diabetic rats showed significant cardiac hypertrophy, body weight loss, hyperglycemia, and hyperlipidemia. Serum creatine kinase MB (CK-MB) and troponin I showed a significant increase in diabetic rats. Simvastatin significantly improved body weight, attenuated hyperglycemia and hyperlipidemia, and ameliorated CK-MB and troponin I. Simvastatin prevented histological alterations and deposition of collagen in the heart of diabetic animals. Lipid peroxidation and nitric oxide were increased in the heart of diabetic rats whereas antioxidant defenses were decreased. These alterations were significantly reversed by simvastatin. In addition, simvastatin decreased serum inflammatory mediators and expression of NF-κB in the diabetic heart. Cardiac caspase-3 was increased in the diabetic heart and decreased following treatment with simvastatin. In conclusion, our results suggest that simvastatin alleviates DCM by attenuating hyperglycemia/hyperlipidemia-induced oxidative stress, inflammation, and apoptosis.
| S-EPMC5613468 | biostudies-other
Project description:Aim: Sirtuin3 (sirt3) plays a pivotal role in improving oxidative stress and mitochondrial dysfunction which directly induced neuronal apoptosis after intracerebral hemorrhage (ICH). Reactive oxygen species (ROS) is also a critical activator in triggering NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasomes activation which can regulate inflammatory responses in brain. Moreover, hyperglycemia can aggravate the ICH-induced damage. Hence, this study was designed to investigate the mechanisms of neuroprotection of sirt3 in hyperglycemic ICH. Methods: ICH model was established by autologous blood injection. Hyperglycemia was induced by intraperitoneal injection with streptozotocin. Honokiol (HKL, a pharmacological agonist of sirt3) was injected intraperitoneally at doses of 2.5, 5, or 10 mg/kg. Sirt3 small interfering RNA transfection was implemented through intracerebroventricular injection. The expression of sirt3 and its downstream signaling molecules were detected using Western blotting or immunofluorescence staining. Morphological changes of mitochondria were detected by electron microscopy. SH-SY5Y cells were incubated with 10 μM oxyhemoglobin for 48 h to establish an in vitro ICH model, and then JC-1 staining was used to determine mitochondrial membrane potential (Δψm). Results: Hyperglycemia could suppress sirt3 expression after ICH when compared with non-diabetic rats. Sirt3 protein expression was decreased to the minimum at 24 h in perihematoma tissues. Electron microscope analysis indicated that hyperglycemic ICH induced extensive mitochondrial vacuolization. HKL attenuated ROS accumulation, adenosine triphosphate reduction, and Δψm through Sirt3-superoxide dismutase 2 (SOD2) and Sirt3-NRF1-TFAM pathway. Sirt3 knockdown could exacerbate the neuronal apoptosis and reverse the positive effects of HKL. Sirt3 activation could decrease NLRP3 and interleukin-1β levels through deacetylating SOD2 and scavenging ROS. Conclusion: HKL protects against hyperglycemic ICH-induced neuronal injury via a sirt3-dependent manner.
| S-EPMC6018086 | biostudies-literature
Project description:Background and purposeThe effects of metformin, an antidiabetic agent that improves insulin sensitivity, on endothelial function have not been fully elucidated. This study was designed to assess the effect of metformin on impaired endothelial function, oxidative stress, inflammation and advanced glycation end products formation in type 2 diabetes mellitus.Experimental approachGoto-Kakizaki (GK) rats, an animal model of nonobese type 2 diabetes, fed with normal and high-fat diet during 4 months were treated with metformin for 4 weeks before evaluation. Systemic oxidative stress, endothelial function, insulin resistance, nitric oxide (NO) bioavailability, glycation and vascular oxidative stress were determined in the aortic rings of the different groups. A pro-inflammatory biomarker the chemokine CCL2 (monocyte chemoattractant protein-1) was also evaluated.Key resultsHigh-fat fed GK rats with hyperlipidaemia showed increased vascular and systemic oxidative stress and impaired endothelial-dependent vasodilatation. Metformin treatment significantly improved glycation, oxidative stress, CCL2 levels, NO bioavailability and insulin resistance and normalized endothelial function in aorta.Conclusion and implicationsMetformin restores endothelial function and significantly improves NO bioavailability, glycation and oxidative stress in normal and high-fat fed GK rats. This supports the concept of the central role of metformin as a first-line therapeutic to treat diabetic patients in order to protect against endothelial dysfunction associated with type 2 diabetes mellitus.
| S-EPMC3087142 | biostudies-literature
Project description:Foxtail millet (FM) is receiving ongoing increased attention due to its beneficial health effects, including the hypoglycemic effect. However, the underlying mechanisms of the hypoglycemic effect have been underexplored. In the present study, the hypoglycemic effect of FM supplementation was confirmed again in high-fat diet and streptozotocin-induced diabetic rats with significantly decreased fasting glucose (FG), glycated serum protein, and areas under the glucose tolerance test (p < 0.05). We employed 16S rRNA and liver RNA sequencing technologies to identify the target gut microbes and signaling pathways involved in the hypoglycemic effect of FM supplementation. The results showed that FM supplementation significantly increased the relative abundance of Lactobacillus and Ruminococcus_2, which were significantly negatively correlated with FG and 2-h glucose. FM supplementation significantly reversed the trends of gene expression in diabetic rats. Specifically, FM supplementation inhibited gluconeogenesis, stimulated glycolysis, and restored fatty acid synthesis through activation of the PI3K/AKT signaling pathway. FM also reduced inflammation through inhibition of the NF-κB signaling pathway. Spearman's correlation analysis indicated a complicated set of interdependencies among the gut microbiota, signaling pathways, and metabolic parameters. Collectively, the above results suggest that the hypoglycemic effect of FM was at least partially mediated by the increased relative abundance of Lactobacillus, activation of the PI3K/AKT signaling pathway, and inhibition of the NF-κB signaling pathway.
| S-EPMC8228963 | biostudies-literature
Project description:Diabetes in pregnancy is a major burden with acute and long-term consequences. Its treatment requires adequate diagnosis and monitoring of therapy. Many experimental research on diabetes during pregnancy has been performed in rats. Recently, continuous blood glucose monitoring of non-pregnant diabetic rats revealed an increased circadian variability of blood glucose that made a single blood glucose measurement per day inappropriate to reflect glycemic status. Continuous blood glucose measurement has never been performed in pregnant rats. We wanted to perform continuous blood glucose monitoring in pregnant rats to decipher the influence of pregnancy on blood glucose in diabetic and normoglycemic status.We used the transgenic Tet29 diabetes rat model with an inducible knock down of the insulin receptor via RNA interference upon application of doxycycline (DOX) leading to insulin resistant type II diabetes. All Tet29 rats received a HD-XG telemetry implant (Data Sciences International, USA) that measured blood glucose and activity continuously. Rats were divided into four groups and blood glucose was monitored until end of pregnancy or the corresponding period: Tet29?+?DOX (diabetic) non-pregnant, Tet29?+?DOX (diabetic) pregnant, Tet29 (normoglycemic) non-pregnant, Tet29 (normoglycemic) pregnant.All analyzed rats displayed a circadian variation in blood glucose concentration. Circadian variability was much more pronounced in pregnant diabetic rats than in normoglycemic pregnant rats. Pregnancy ameliorated variation in blood glucose in diabetic situation. Pregnancy continuously decreased blood glucose during normoglycemic pregnancy. Diabetic rats were less active than normoglycemic rats. We performed a calculation showing that application of continuous blood glucose measurement reduces animal numbers needed to detect a given effect in experimental setting by decreasing variability and SD.Continuous blood glucose monitoring via a telemetry device in pregnant rats provides a more informative picture of the glycemic situation in comparison to single measurements. This could improve diagnosis and therapy of diabetes, decrease animal numbers within experimental settings, and add another physiological parameter (activity) to the analysis that could be helpful in testing therapeutic concepts targeting blood glucose levels and peripheral muscle function. We propose continuous glucose monitoring as a new tool for the evaluation of pregnant diabetic rats.
| S-EPMC5986873 | biostudies-literature
Project description:Effects of ARA290 on glucose homeostasis were studied in type 2 diabetic Goto-Kakizaki (GK) rats. In GK rats receiving ARA290 daily for up to 4 wks, plasma glucose concentrations were lower after 3 and 4 wks, and hemoglobin A1c (Hb A1c) was reduced by ~20% without changes in whole body and hepatic insulin sensitivity. Glucose-stimulated insulin secretion was increased in islets from ARA290-treated rats. Additionally, in response to glucose, carbachol and KCl, islet cytoplasmic free Ca2+ concentrations, [Ca2+]i, were higher and the frequency of [Ca2+]i oscillations enhanced compared with placebo. ARA290 also improved stimulus-secretion coupling for glucose in GK rat islets, as shown by an improved glucose oxidation rate, ATP production and acutely enhanced glucose-stimulated insulin secretion. ARA290 also exerted an effect distal to the ATP-sensitive potassium (KATP) channel on the insulin exocytotic pathway, since the insulin response was improved following islet depolarization by KCl when KATP channels were kept open by diazoxide. Finally, inhibition of protein kinase A completely abolished effects of ARA290 on insulin secretion. In conclusion, ARA290 improved glucose tolerance without affecting hematocrit in diabetic GK rats. This effect appears to be due to improved γ-cell glucose metabolism and [Ca2+]i handling, and thereby enhanced glucose-induced insulin release.
| S-EPMC4818260 | biostudies-literature
Project description:BackgroundDiet acts on the human body through digestion in the stomach and absorption in the intestines. Thus, the emptying of the stomach should be the focus of the research mechanism of the combined medicine and food treatment of diabetes. The emptying function of the stomach and the secretion of related hormones may be the key points of traditional Chinese medicine. In the clinic, Yunvjian is a famous traditional Chinese formula for preventing and curing diabetes. However, the pharmacological action and mechanism of Yunvjian are also need to be probe.ObjectiveTo assess the effect of Yunvjian on glucose, insulin level and gastric emptying function and related hormones on high-fat diet combined with STZ-induced diabetic rats.MethodsHigh-fat diet combined with STZ was used to construct type 2 diabetes mellitus (T2DM) rats model and received a 4-week Yunvjian administration. The animals were divided into 6 groups, respectively, as the Control group, the DM group, the DM + Acarbose group, the DM + YNH group, and the DM + YNL group. Radionuclide single-photon emission computed tomography (SPECT) technology was used to observe the gastric emptying rate and half-empty time; blood was took to test fasting insulin, and then the insulin resistance index (HOMA-IR) was calculated; HE staining was performed to detect islets and gastric antrum, immunohistochemical staining was performed to detect the number and morphology of pancreatic β cells and gastric antrum Cajal cells, and the average optical density was calculated; the expression of ghrelin hormone in gastric antrum and serum was detected by ELISA and immunofluorescence; the expression of GHRS mRNA in gastric antrum was detected by RT-PCR method.ResultsYunvjian could significantly improve the glucose level and insulin function of rats. Compared with the DM group, Yunvjian was beneficial to low fasting blood glucose (FBG) (P < 0.01), increased glucose tolerance, and improved islet function at the same time (P < 0.05). At the same time, compared with the DM group (25.02 ± 0.05, 44 ± 12.33), the emptying rate of the DM + YNH group was significantly faster (64.98 ± 0.12), and the half row time was shortened (26 ± 8.29, P < 0.05). The gastric ghrelin levels in each group of Yunvjian increased with different degrees compared with the DM group (616.2 ± 26.23), especially in the DM + YNH group (863.51 ± 23.76, P < 0.01). Correspondingly, the expression of gastric GHSR mRNA in the DM + YNH and DM + YNL groups increased significantly compared with the DM group (P < 0.01).ConclusionsYunvjian can effectively control glucose and improve islet function, which may be closely related to its influence on gastric emptying function and related hormone secretion regulation.
| S-EPMC9867596 | biostudies-literature
Project description:ObjectivesCardiovascular diseases are widespread across the globe, and heart failure (HF) accounts for the majority of heart-associated deaths. Target-based drug therapy is much needed for the management of heart failure. We have designed this study to evaluate icariin for its cardioprotective activity in the isoproterenol (ISO) induced postinfarction model. We have randomly distributed Wistar rats into seven groups, i.e., vehicle control; isoproterenol-treated; icariin per se; sildenafil per se; ISO + icariin 5; ISO + icariin 10; and ISO + sildenafil groups. ISO (85 mg/kg, subcutaneous) was administered at 24 hr for two consecutive days to produce cardiac injury, followed by icariin administration at 5 mg/kg and 10 mg/kg orally for 56 days.Materials and methodsRats were subjected to hemodynamic measurements biweekly. After 24 hr of the completion of dosing, animals were sacrificed, and markers for oxidative stress, fibrosis, inflammation, and cell death were measured. Transmission electron microscopy (TEM), histopathology, and MT staining of cardiac tissue were also done to assess the pathological and fibrotic architectural damage.ResultsA significant decline in hemodynamics and an anti-oxidant collapse were found in ISO-intoxicated rats. Alterations in the levels of cyclic guanosine monophosphate (cGMP), interleukin-10 (IL-10), Tumor necrosis factor (TNF-α), and brain natriuretic peptide (BNP) were also observed in serum. Up-regulation of caspase-3, nuclear factor (NF-ĸB), and decline in expression of nuclear factor (NrF-2) contribute to cardiac damage. The treatment with icariin and sildenafil considerably reversed the toxic changes toward normal.ConclusionIncreased cGMP and Nrf2 expression and suppressed NF-ĸB-caspase-3 signaling play a pivotal role in icariin-mediated cardioprotection.
| S-EPMC10083836 | biostudies-literature
Project description:Mitochondrial dysfunction and oxidative stress play an important role in the pathogenesis of both atrial fibrillation (AF) and diabetes mellitus (DM). Wenxin Keli (WXKL), an antiarrhythmic traditional Chinese medicine, has been shown to prevent cardiac arrhythmias through modulation of cardiac ion channels. This study tested the hypothesis that WXKL can improve atrial remodeling in diabetic rats by restoring mitochondrial function. Primary atrial fibroblasts of neonatal SD rats were divided into four groups: control, hydrogen peroxide (H2O2), H2O2+WXKL 1?g/L, and H2O2+WXKL 3?g/L groups. Intracellular mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and mitochondrial oxygen consumption were measured. SD male rats were randomly divided into three groups: control, DM, and DM+WXKL groups. Rats in the DM+WXKL group were treated with daily gavage of WXKL at 3?g/kg. After eight weeks, echocardiography, hemodynamic examination, histology, electrophysiology study, mitochondrial respiratory function, and western blots were assessed. H2O2 treatment led to increased ROS and decreased intracellular MMP and mitochondrial oxygen consumption in primary atrial fibroblasts. WXKL improved the above changes. DM rats showed increased atrial fibrosis, greater left atrial diameter, lower atrial conduction velocity, higher conduction heterogeneity, higher AF inducibility, and lower mitochondrial protein expression, and all these abnormal changes except for left atrial diameter were improved in the DM+WXKL group. WXKL improves atrial remodeling by regulating mitochondrial function and homeostasis and reducing mitochondrial ROS in diabetic rats.
| S-EPMC7040409 | biostudies-literature