62 research outputs found
Interaction of regular exercise and chronic nitroglycerin treatment on blood pressure and rat aortic antioxidants
AbstractMany cardiac patients undergo exercise conditioning with or without medication. Therefore, we investigated the interaction of exercise training and chronic nitroglycerin treatment on blood pressure (BP), aortic nitric oxide (NO), oxidants and antioxidants in rats. Fisher 344 rats were divided into four groups and treated as follows: (1) sedentary control, (2) exercise training (ET) for 8 weeks, (3) nitroglycerin (15 mg/kg, s.c. for 8 weeks) and (4) ET+nitroglycerin. BP was monitored with tail-cuff method. The animals were sacrificed 24 h after the last treatments and thoracic aorta was isolated and analyzed. Exercise training on treadmill for 8 weeks significantly increased respiratory exchange ratio (RER), aortic NO levels, and endothelial nitric oxide synthase (eNOS) protein expression. Training significantly enhanced aortic glutathione (GSH), reduced to oxidized glutathione (GSH/GSSG) ratio, copper/zinc-superoxide dismutase (CuZn-SOD), Mn-SOD, catalase (CAT), glutathione peroxidase (GSH-Px) glutathione disulfide reductase (GR) activities and protein expressions. Training significantly depleted aortic malondialdehyde (MDA) and protein carbonyls without change in BP. Nitroglycerin administration for 8 weeks significantly increased aortic NO levels and eNOS protein expression. Nitroglycerin significantly enhanced aortic Mn-SOD, CAT, GR and glutathione-S-transferase (GST) activities and protein expressions with decreased MDA levels, protein carbonyls and BP. Interaction of training and nitroglycerin treatment significantly increased aortic NO levels, eNOS protein expression, GSH/GSSG ratio, antioxidant enzymes and normalized BP. The data suggest that the interaction of training and nitroglycerin maintained BP by up-regulating the aortic NO and antioxidants and reducing the oxidative stress in rats
Vitamin E δ-tocotrienol Sensitizes Human Pancreatic Cancer Cells to TRAIL-induced Apoptosis Through Proteasome-Mediated Down-Regulation of c-FLIP
Background: Vitamin E δ-tocotrienol (VEDT), a vitamin E compound isolated from sources such as palm fruit and annatto beans, has been reported to have cancer chemopreventive and therapeutic effects.
Methods: We report a novel function of VEDT in augmenting tumor necrosis factor-related apoptosis-inducing ligand- (TRAIL-) induced apoptosis in pancreatic cancer cells. The effects of VEDT were shown by its ability to trigger caspase-8-dependent apoptosis in pancreatic cancer cells.
Results: When combined with TRAIL, VEDT significantly augmented TRAIL-induced apoptosis of pancreatic cancer cells. VEDT decreased cellular FLICE inhibitory protein (c-FLIP) levels without consistently modulating the expression of decoy death receptors 1, 2, 3 or death receptors 4 and 5. Enforced expression of c-FLIP substantially attenuated VEDT/TRAIL-induced apoptosis. Thus, c-FLIP reduction plays an important part in mediating VEDT/TRAIL-induced apoptosis. Moreover, VEDT increased c-FLIP ubiquitination and degradation but did not affect its transcription, suggesting that VEDT decreases c-FLIP levels through promoting its degradation. Of note, degradation of c-FLIP and enhanced TRAIL-induced apoptosis in pancreatic cancer cells were observed only with the anticancer bioactive vitamin E compounds δ-, γ-, and β-tocotrienol but not with the anticancer inactive vitamin E compounds α-tocotrienol and α-, β-, γ-, and δ-tocopherol.
Conclusions: c-FLIP degradation is a key event for death receptor-induced apoptosis by anticancer bioactive vitamin E compounds in pancreatic cancer cells. Moreover, VEDT augmented TRAIL inhibition of pancreatic tumor growth and induction of apoptosis in vivo. Combination therapy with TRAIL agonists and bioactive vitamin E compounds may offer a novel strategy for pancreatic cancer intervention
Assessment of the Cytotoxic Activity of Triphala: A Semisolid Traditional Formulation on HepG2 Cancer Cell Line
Cancer chemotherapies may result in resistance, and therefore, contemporary treatments including natural products may find an increasing consideration. As per Persian medicine (PM), many natural products have been used for malignant and chronic diseases. Triphala, with a combination of Terminalia chebula Retz., Terminalia bellirica Retz., Phyllanthus emblica L., and honey, is a multi-ingredient traditional formulation attributed to anticancer activities in PM. This study is aimed at evaluating the cytotoxic activity of this preparation on HepG2, the human liver cancer cell line. Hydroalcoholic extracts were prepared from the formulation and its components. Compared with the control and Cisplatin, the extracts were tested using MTT assay at different concentrations. All concentrations of the preparation, as well as Cisplatin, were effective significantly against HepG2 cells. All extract preparations at multiple concentrations were significantly effective as evidenced by MTT assay when compared to the control group. The IC50 level for Triphala extract was 77.63±4.3 μg/ml. Based on the results, Triphala and its components have cytotoxic activity on the HepG2 cancer cell line and they can reduce the survival rate significantl
Effects of Antioxidant N-acetylcysteine Against Paraquat-Induced Oxidative Stress in Vital Tissues of Mice
PQ enhanced lipid peroxidation (MDA) levels in liver tissue compared to control whereas NAC decreased MDA levels (p<0.05). NAC significantly increased MDA in brain tissue (p<0.05). PQ significantly depleted glutathione (GSH) levels in liver (p=0.001) and brain tissue (p<0.05) but non-significant GSH depletion in lung tissue. NAC counteracted PQ, showing a moderate increase GSH levels in liver and brain tissues. PQ significantly increased 8-oxodeoxyguanosine (8-OH-dG) levels (p<0.05) in liver tissue compared to control without a significant change in brain tissue. NAC treatment ameliorated PQ-induced oxidative DNA damage in the liver tissue. PQ significantly decreased the relative mtDNA amplification and increased the frequency of lesions in liver and brain tissue (p<0.0001), while NAC restored the DNA polymerase activity in liver tissue but not in brain tissue. In conclusion, PQ induced lipid peroxidation, oxidative nuclear DNA and mtDNA damage in liver tissues and depleted liver and brain GSH levels. NAC supplementation ameliorated the PQ-induced oxidative stress response in liver tissue of mice. Paraquat (PQ) is a commonly used herbicide that induces oxidative stress via reactive oxygen species (ROS) generation. This study aimed to investigate the effects of the antioxidant N-acetylcysteine (NAC) against PQ-induced oxidative stress in mice. Male Balb/C mice (24) were randomly divided into 4 groups and treated for 3 weeks: 1) control (saline), 2) NAC (0.5% in diet), 3) PQ (20 mg/kg, IP) and 4) combination (PQ + NAC). Afterwards mice were sacrificed and oxidative stress markers were analyzed. Our data showed no significant change in serum antioxidant capacity
Electric footshocks differentially affect plasma and spinal cord vasopressin and oxytocin levels
Murine Pancreatic Adenocarcinoma Reduces Ikaros Expression and Disrupts T Cell Homeostasis
Background
Maintenance of T cell immune homeostasis is critical for adequate anti-tumor immunity. The transcription factor Ikaros is essential for lymphocyte development including T cells. Alterations in Ikaros expression occur in blood malignancies in humans and mice. In this study, we investigated the role of Ikaros in regulating T cell immune balance in pancreatic cancer mouse models.
Methodology and Principal Findings
Using our Panc02 tumor-bearing (TB) mouse model, western blot analysis revealed a reduction in Ikaros proteins while qRT-PCR showed no differences in Ikaros mRNA levels in TB splenocytes compared to control. Treatment of naïve splenocytes with the proteasomal inhibitor, MG132, stabilized Ikaros expression and prevented Ikaros downregulation by Panc02 cells, in vitro. Western blot analyses showed a reduction in protein phosphatase 1 (PP1) and protein kinase CK2 expression in TB splenocytes while CK2 activity was increased. Immunofluorescence microscopy revealed altered punctate staining of Ikaros in TB splenocytes. Flow cytometry revealed a significant decrease in effector CD4+ and CD8+ T cell percentages but increased CD4+CD25+ regulatory T cells in TB splenocytes. Similar alterations in T cell percentages, as well as reduced Ikaros and CK2 but not PP1 expression, were observed in a transgenic, triple mutant (TrM) pancreatic cancer model. Ikaros expression was also reduced in enriched TB CD3+ T cells. MG132 treatment of naïve CD3+ T cells stabilized Ikaros expression in the presence of Panc02 cells. Western blots showed reduced PP1 and CK2 expression in TB CD3+ T cells.
Conclusions/Significance
The results of this study suggest that the pancreatic tumor microenvironment may cause proteasomal degradation of Ikaros, possibly via dysregulation of PP1 and CK2 expression and activity, respectively. This loss of Ikaros expression may contribute to an imbalance in T cell percentages. Ikaros may potentially be a therapeutic target to restore T cell homeostasis in pancreatic cancer hosts, which may be critical for effective anti-tumor immunity
Ventricular Dysrhythmias Associated with Poisoning and Drug Overdose: A 10-Year Review of Statewide Poison Control Center Data from California
Background: Ventricular dysrhythmias are a serious consequence associated with drug overdose and chemical poisoning. The risk factors for the type of ventricular dysrhythmia and the outcomes by drug class are not well documented. Objective: The aim of this study was to determine the most common drugs and chemicals associated with ventricular dysrhythmias and their outcomes. Methods: We reviewed all human exposures reported to a statewide poison control system between 2002 and 2011 that had a documented ventricular dysrhythmia. Cases were differentiated into two groups by type of arrhythmia: (1) ventricular fibrillation and/or tachycardia (VT/VF); and (2) torsade de pointes (TdP). Results: Among the 300 potential cases identified, 148 cases met the inclusion criteria. Of these, 132 cases (89 %) experienced an episode of VT or VF, while the remaining 16 cases (11 %) had an episode of TdP. The most commonly involved therapeutic classes of drugs associated with VT/VF were antidepressants (33/132, 25 %), stimulants (33/132, 25 %), and diphenhydramine (16/132, 12.1 %). Those associated with TdP were antidepressants (4/16, 25 %), methadone (4/16, 25 %), and antiarrhythmics (3/16, 18.75 %). Drug exposures with the greatest risk of death in association with VT/VF were antidepressant exposure [odds ratio (OR) 1.71; 95 % confidence interval (CI) 0.705–4.181] and antiarrhythmic exposure (OR 1.75; 95 % CI 0.304–10.05), but neither association was statistically significant. Drug exposures with a statistically significant risk for TdP included methadone and antiarrhythmic drugs. Conclusions: Antidepressants and stimulants were the most common drugs associated with ventricular dysrhythmias. Patients with suspected poisonings by medications with a high risk of ventricular dysrhythmia warrant prompt ECG monitoring
Alcoholic Beverages-Induced Hypertension and Its Management
Alcoholic (ethanol containing) beverages have been part of human culture for thousands of years around the world. They are divided into three general classes namely bears, wines and spirits and typically contain 5%, 12% and 40% alcohol by volume. Preclinical and clinical studies have revealed the association between consumption of alcoholic beverages and elevation of blood pressure or hypertension. The exact mechanism of alcoholic beverages-induced hypertension remains elusive. However several possible mechanisms have been reported: an imbalance of the nervous system, stimulation of the renin-angiotensin-aldosterone system, increased cortisol levels, increased intracellular calcium levels, induction of vascular endothelial oxidative stress. For the management of alcoholic beverages-induced hypertension non-pharmacological strategies are: reduction of alcoholic beverage intake, weight reduction, reduction of salt and caffeine intake, smoking (nicotine) cessation and promotion of physical activity. Pharmacologic treatment includes dexamethasone for acute alcoholic beverage-induced hypertension, angiotensin-converting enzyme inhibitors, angiotensin II type 1 receptor blockers and calcium channel blockers are recommended for chronic alcoholic beverages-induced hypertension
Therapeutic Intervention of Human Pancreatic Cancer
Pancreatic cancer is one of the most lethal malignancies in the world. The incidence of pancreatic cancer keeps on increasing without a significant decrease in mortality. Current therapeutic options are surgical resections, radiation, and chemo, biologic, immune and palliative therapy. Surgical therapies are associated with acceptable outcomes but resected patients suffer from tumor recurrence. The role of post-operative radiotherapy reported increased survival. Currently four chemotherapy drugs approved by the United States Food and Drug Administration (US FDA) for the treatment of pancreatic cancer: ABRAXANE (albumin-bound paclitaxel), gemcitabine, 5-fluorouracil (5- FU) and ONIVYDE (irinotecan liposome injection). Among the conventional chemotherapies the combination of abraxane (nab-paclitaxel) with gemcitabine and FOLFIRINOX (5-FU/leucovorin, irinotecan, oxaliplatin) in metastatic pancreatic cancer patients are promising. Among the targeted therapies the combination of gemcitabine, erlotinib and capecitabine are likely to form the base for future treatment. Under biologic or immunotherapy antibodies against programmed death-1 receptor (PD-1), its ligand PD-L1, cytotoxic T lymphocyte associated antigen-4 (CTLA-4), KRAStargeting vaccines, mucin-1 (MUC1) vaccine, telomerase-targeting vaccine (GV1001), gastrinbased vaccine, dendritic cell (DC)-based vaccine alone or combined with Lymphokine Activated Killer (LAK) cells and allogeneic GM-CSF-secreting vaccine (GVAX) are new therapeutic option for pancreatic cancer. Current and future clinical trials using natural compounds such as deltatocotrienol, Huang-Qin-Tang (HQT) and its botanical formulation (PHY906) and curcumin in combination with other agents are ongoing to discover more effective ways of treating pancreatic cancer patients
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