ascorbic-acid and acetovanillone

1. In the present review, we addressed studies in humans and rats to determine the role that oxidative stress may play in mediating cardiovascular outcomes. 2. Biochemical evaluation of oxidative stress in both humans and spontaneously hypertensive rats gives equivocal results as to the relative levels in males versus females. Clinical trials with anti-oxidants in humans have not shown consistent results in protecting against detrimental cardiovascular outcomes. In spontaneously hypertensive rats (SHR), blockade studies using tempol or apocynin reduce renal oxidative stress and blood pressure in male SHR, but not in female rats. In addition, increasing oxidative stress with molsidomine increases blood pressure in male, but not female, SHR. Treatment with vitamins E and C reduces blood pressure in young male, but not aged, animals. Furthermore tempol is unable to reduce blood pressure in young male SHR in the absence of a functional nitric oxide system. 3. Neither human nor animal studies are consistent in terms of whether oxidative stress levels are higher in males or females. Furthermore, anti-oxidant therapy in humans often does not ameliorate, or even attenuate, the negative cardiovascular consequences of increased oxidative stress. Our studies in SHR shed light on why these outcomes occur.

Topics: Acetophenones; Animals; Antioxidants; Ascorbic Acid; Blood Pressure; Cardiovascular Diseases; Catalase; Cyclic N-Oxides; Enzyme Inhibitors; Female; Glutathione Peroxidase; Humans; Hypertension; Kidney; Male; Molsidomine; NADPH Oxidases; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Oxidative Stress; Rats; Rats, Inbred SHR; Sex Factors; Spin Labels; Superoxide Dismutase; Vitamin E

To reduce the increase of oxidative stress and the upregulation of CD40L during stenting procedure using ascorbic acid infusion.. CD40L upregulation occurring after coronary percutaneous coronary intervention predicts vascular events but the underlying mechanism is still unclear.. Fifty-six patients undergoing elective coronary stenting were randomly allocated to intravenous infusion of the antioxidant ascorbic acid or placebo. Platelet CD40L and plasma levels of soluble CD40L and of 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress, were measured before and after coronary stenting. In vitro study was also done to measure reactive oxidant species and CD40L expression in platelets exposed to anoxia-reoxygenation.. Placebo-treated patients showed a significant increase of platelet CD40L, soluble CD40L and 8-hydroxy-2'-deoxyguanosine compared to baseline values. Patients given ascorbic acid showed no change of soluble CD40L and platelet CD40L but a significant decrease of 8-hydroxy-2'-deoxyguanosine. After 60 and 120 min, soluble CD40L, platelet CD40L and 8-hydroxy-2'-deoxyguanosine were significantly lower in the ascorbic acid-treated group compared to the placebo-treated one. A significant correlation between platelet CD40L and soluble CD40L and between soluble CD40L and 8-hydroxy-2'-deoxyguanosine was observed. Platelets, in vitro exposed to anoxia-reoxygenation, had a burst of ROS and an upregulation of CD40L that were inhibited by ascorbic acid or apocynin, an inhibitor of NADPH oxidase.. This study shows that in patients undergoing coronary stenting CD40L is upregulated with a mechanism which is likely mediated by oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetophenones; Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Antioxidants; Ascorbic Acid; Biomarkers; Blood Platelets; CD40 Ligand; Coronary Artery Disease; Deoxyguanosine; Enzyme Inhibitors; Female; Flow Cytometry; Humans; Infusions, Intravenous; Italy; Linear Models; Male; Middle Aged; NADPH Oxidases; Oxidative Stress; Pilot Projects; Placebos; Prospective Studies; Reactive Oxygen Species; Stents; Time Factors; Treatment Outcome; Up-Regulation

A number of neurological disorders such as epidural hematoma can cause compression of cerebral cortex. We here tested the hypothesis that sustained compression of primary somatosensory cortex may affect stellate neurons and thalamocortical afferent (TCA) fibers. A rat model with barrel cortex subjected to bead epidural compression was used. Golgi-Cox staining analyses showed the shrinkage of dendritic arbors and the stripping of dendritic spines of stellate neurons for at least 3 months post-lesion. Anterograde tracing analyses exhibited a progressive decline of TCA fiber density in barrel field for 6 months post-lesion. Due to the abrupt decrease of TCA fiber density at 3 days after compression, we further used electron microscopy to investigate the ultrastructure of TCA fibers at this time. Some TCA fiber terminal profiles with dissolved or darkened mitochondria and fewer synaptic vesicles were distorted and broken. Furthermore, the disruption of mitochondria and myelin sheath was observed in some myelinated TCA fibers. In addition, expressions of oxidative markers 3-nitrotyrosine and 4-hydroxynonenal were elevated in barrel field post-lesion. Treatment of antioxidant ascorbic acid or apocynin was able to reverse the increase of oxidative stress and the decline of TCA fiber density, rather than the shrinkage of dendrites and the stripping of dendritic spines of stellate neurons post-lesion. Together, these results indicate that sustained epidural compression of primary somatosensory cortex affects the TCA fibers and the dendrites of stellate neurons for a prolonged period. In addition, oxidative stress is responsible for the reduction of TCA fiber density in barrels rather than the shrinkage of dendrites and the stripping of dendritic spines of stellate neurons.

Topics: Acetophenones; Afferent Pathways; Aldehydes; Animals; Antioxidants; Ascorbic Acid; Biotin; Brain Injuries; Dendrites; Dextrans; Disease Models, Animal; Electron Transport Complex IV; Epidural Space; Functional Laterality; Male; Neurons; Oxidative Stress; Rats; Somatosensory Cortex; Thalamus; Time Factors; Tyrosine

Hair cells are highly sensitive to environmental insults and other therapeutic drugs. The adverse effects of drugs such as aminoglycosides can cause hair cell death and lead to hearing loss and imbalance. The objective of the present study was to evaluate the protective activity of L-ascorbic acid, N-acetylcysteine (NAC) and apocynin on neomycin-induced hair cell damage in zebrafish (Danio rerio) larvae at 5 days post fertilization (dpf). Results showed that the loss of hair cells within the neuromasts of the lateral lines after neomycin exposure was evidenced by a significantly lower number of neuromasts labeled with fluorescent dye FM1-43FX observed under a microscope. Co-administration with L-ascorbic acid, NAC and apocynin protected neomycin-induced hair cell loss within the neuromasts. Moreover, these three compounds reduced the production of reactive oxygen species (ROS) in neuromasts exposed to neomycin, indicating that their antioxidant action is involved. In contrast, the neuromasts were labeled with specific fluorescent dye Texas-red conjugated with neomycin to detect neomycin uptake. Interestingly, the uptake of neomycin into hair cells was not influenced by these three antioxidant compounds. These data imply that prevention of hair cell damage against neomycin by L-ascorbic acid, NAC and apocynin might be associated with inhibition of excessive ROS production, but not related to modulating neomycin uptake. Our findings conclude that L-ascorbic acid, NAC and apocynin could be used as therapeutic drugs to protect aminoglycoside-induced listening impairment after further confirmatory studies.

Topics: Acetophenones; Acetylcysteine; Animal Use Alternatives; Animals; Anti-Bacterial Agents; Antioxidants; Ascorbic Acid; Cell Survival; Embryo, Nonmammalian; Hair Cells, Auditory, Inner; Mechanoreceptors; Microscopy, Confocal; Neomycin; Oxidative Stress; Reactive Oxygen Species; Zebrafish

Stress is a potent risk factor for depression, yet the underlying mechanism is not clearly understood. In the present study, we explored the mechanism of development and maintenance of depression in a stress-induced animal model. Mice restrained for 2 h daily for 14 d showed distinct depressive behavior, and the altered behavior persisted for >3 months in the absence of intervention. Acute restraint induced a surge of oxidative stress in the brain, and stress-induced oxidative stress progressively increased with repetition of stress. In vitro, the stress hormone glucocorticoid generated superoxide via upregulation of NADPH oxidase. Consistently, repeated restraints increased the expression of the key subunits of NADPH oxidase, p47phox and p67phox, in the brain. Moreover, stressed brains markedly upregulated the expression of p47phox to weak restress evoked in the poststress period, and this molecular response was reminiscent of amplified ROS surge to restress. Pharmacological inhibition of NADPH oxidase by the NADPH oxidase inhibitor apocynin during the stress or poststress period completely blocked depressive behavior. Consistently, heterozygous p47phox knock-out mice (p47phox(+/-)) or molecular inhibition of p47phox with Lenti shRNA-p47phox in the hippocampus suppressed depressive behavior. These results suggest that repeated stress promotes depressive behavior through the upregulation of NADPH oxidase and the resultant metabolic oxidative stress, and that the inhibition of NADPH oxidase provides beneficial antidepression effects.

Topics: Acetophenones; Analysis of Variance; Animals; Antidepressive Agents, Tricyclic; Antioxidants; Ascorbic Acid; Brain; Cell Line; Corticosterone; Depressive Disorder; Disease Models, Animal; Drug Administration Schedule; Gene Expression Regulation, Enzymologic; Green Fluorescent Proteins; Hindlimb Suspension; Hippocampus; Humans; Hydrogen Peroxide; Imipramine; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; NADPH Oxidases; Neuroblastoma; Neurons; Phosphoproteins; Reactive Oxygen Species; Restraint, Physical; RNA, Messenger; RNA, Small Interfering; Social Behavior; Superoxides; Swimming; Time Factors

Patients on a low salt (LS) diet have increased mortality.. To determine whether reduction in NO bioactivity may contribute to the LS-induced cardiac dysfunction and mortality.. Adult male mongrel dogs were placed on LS (0.05% sodium chloride) for 2 weeks. Body weight (25.4 + or - 0.4 to 23.6 + or - 0.4 kg), left ventricular systolic pressure (137.0 + or - 3.4 to 124.0 + or - 6.7 mm Hg), and mean aortic pressure (111 + or - 3.1 to 98 + or - 4.3 mm Hg) decreased. Plasma angiotensin II concentration increased (4.4 + or - 0.7 to 14.8 + or - 3.7 pg/mL). Veratrine-induced (5 microg/kg) NO-mediated vasodilation was inhibited by 44% in LS; however, the simultaneous intravenous infusion of ascorbic acid or apocynin acutely and completely reversed this inhibition. In LS heart tissues, lucigenin chemiluminescence was increased 2.3-fold to angiotensin II (10(-8) mol/L), and bradykinin (10(-4) mol/L) induced reduction of myocardial oxygen consumption in vitro was decreased (40 + or - 1.3% to 16 + or - 6.3%) and completely restored by coincubation with tiron, tempol or apocynin. Switching of substrate uptake from free fatty acid to glucose by the heart was observed (free fatty acid: 8.97 + or - 1.39 to 4.53 + or - 1.12 micromol/min; glucose: 1.31 + or - 0.52 to 6.86 + or - 1.78 micromol/min). Western blotting indicated an increase in both p47(phox) (121%) and gp91(phox) (44%) as did RNA microarray analysis (433 genes changed) showed an increase in p47(phox) (1.6-fold) and gp91(phox) (2.0 fold) in the LS heart tissue.. LS diet induces the activation of the renin-angiotensin system, which increases oxidative stress via the NADPH oxidase and attenuates NO bioavailability in the heart.

Topics: Acetophenones; Angiotensin II; Animals; Ascorbic Acid; Coronary Vessels; Diet, Sodium-Restricted; Dogs; Fatty Acids; Gene Expression Profiling; Glucose; Hemodynamics; Infusions, Intravenous; Lactates; Male; Myocardium; NADPH Oxidases; Nitric Oxide; Oligonucleotide Array Sequence Analysis; Oxidative Stress; Oxygen Consumption; Renin-Angiotensin System; Superoxides; Vasodilation; Veratrine; Weight Loss

Arsenite (As(III)), an inorganic arsenical, is a known human carcinogen, inducing tumors of the skin, urinary bladder and lung. It is metabolized to organic methylated arsenicals. Oxidative stress has been suggested as a mechanism for arsenic-induced carcinogenesis. Reactive oxygen species (ROS) can be important factors for carcinogenesis and tumor progression. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is known to produce intracellular ROS, therefore, we investigated the ability of apocynin (acetovanillone), an NADPH oxidase inhibitor, to inhibit the cytotoxicity and regenerative cell proliferation of arsenic in vitro and in vivo. Apocynin had similar effects in reducing the cytotoxicity of As(III) and dimethylarsinous acid (DMA(III)) in rat urothelial cells in vitro. When tested at the same concentrations as apocynin, other antioxidants, such as l-ascorbate and N-acetylcysteine, did not inhibit As(III)-induced cytotoxicity but they were more effective at inhibiting DMA(III)-induced cytotoxicity compared with apocynin. In vivo, female rats were treated for 3 weeks with 100ppm As(III). Immunohistochemical staining for 8-hydroxy-2'-deoxyguanosine (8-OHdG) showed that apocynin reduced oxidative stress partially induced by As(III) treatment on rat urothelium, and significantly reduced the cytotoxicity of superficial cells detected by scanning electron microscopy (SEM). However, based on the incidence of simple hyperplasia and the bromodeoxyuridine (BrdU) labeling index, apocynin did not inhibit As(III)-induced urothelial cell proliferation. These data suggest that the NADPH oxidase inhibitor, apocynin, may have the ability to partially inhibit arsenic-induced oxidative stress and cytotoxicity of the rat bladder epithelium in vitro and in vivo. However, apocynin did not inhibit the regenerative cell proliferation induced by arsenite in a short-term study.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetophenones; Acetylcysteine; Animals; Antioxidants; Arsenites; Ascorbic Acid; Cacodylic Acid; Carcinogens; Cell Line; Cell Proliferation; Cytoprotection; Deoxyguanosine; Diet; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Hyperplasia; NADPH Oxidases; Oxidative Stress; Rats; Rats, Inbred F344; Sodium Compounds; Urinary Bladder; Urothelium

To determine the roles of nitric oxide synthase (NOS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in the impairment of capillary blood flow in sepsis and in the reversal of this impairment by ascorbate.. Prospective, controlled laboratory study.. Animal laboratory in research institute.. Adult male wild type (WT), neuronal nitric oxide synthase (nNOS)-/-, inducible NOS (iNOS)-/-, endothelial NOS (eNOS)-/-, and gp91phox-/- mice.. Sepsis was induced by feces injection into peritoneum (FIP). A bolus of ascorbate or NADPH oxidase inhibitor apocynin was injected intravenously at 6 hrs post-FIP. Alternatively, NOS cofactor (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) or nitric oxide donor S-nitroso-N-acetylpenicillamine was superfused on the surface of the extensor digitorum longus muscle.. Capillary blood flow impairment and NOS activity in the extensor digitorum longus muscle were measured by intravital microscopy and by enzymatic assay, respectively. Sepsis at 6 hrs impaired flow in WT mice. Apocynin, and knockout of gp91phox but not of any NOS isoforms, rescued this impairment. Constitutive NOS activity was unaffected by sepsis, but it was abolished by nNOS knockout (iNOS activity was negligible in all mice). Ascorbate rapidly (10 mins) rescued impaired flow in WT, nNOS-/-, iNOS-/- but not eNOS-/- mice. Ascorbate also improved survival of WT mice after FIP. BH4 and SNAP rescued flow in WT mice, while BH4 failed to rescue it in eNOS-/- mice.. Capillary blood flow impairment in septic skeletal muscle requires NADPH oxidase but not NOS, and it is rapidly reversed by ascorbate and BH4 through an eNOS-dependent mechanism.

Topics: Acetophenones; Animals; Antioxidants; Ascorbic Acid; Capillaries; Male; Mice; Mice, Knockout; Microcirculation; Muscle, Skeletal; NADP; NADPH Oxidases; Nitric Oxide Synthase; Sepsis

Intracellularly generated reactive oxygen species (ROS) are thought to modulate redox sensitive signaling pathways and thus regulate cell physiology including proliferation and differentiation. However, the role of ROS in neuronal differentiation of embryonic pluripotent cells is unknown. For this reason, the modification of retinoic acid (RA) induced neuronal differentiation of mouse embryonal carcinoma cells P19 by selected ROS scavengers and flavoprotein inhibitor was evaluated.. Intracellular ROS was evaluated by flowcytometry. Cellular redox status was evaluated based on total levels of reduced thiol groups in cells. The activity of the RA responsive element (RARE) was evaluated by luciferase reporter assay. The RA-induced neuronal differentiation was determined based on changes in the expression of protein markers characteristic for undifferentiated (Oct-4) and neuron-like cell differentiated cells (N-cadherin and III-beta tubulin).. RA increased the intracellular ROS production that was accompanied by a decrease in thiol groups in cells. The ROS scavengers and flavoprotein inhibitor reduced RA-induced ROS production, RA-induced activity of RARE, and it decreased the RA-induced expression of N-cadherin and III-beta tubulin.. Our data outline a role of ROS as important molecules in the transduction of an intracellular signal during the neuronal differentiation of ES cells.

Topics: Acetophenones; Acetylcysteine; Ascorbic Acid; Blotting, Western; Cell Differentiation; Embryonal Carcinoma Stem Cells; Flow Cytometry; Free Radical Scavengers; Genes, Reporter; Glutathione; Humans; Neurons; Onium Compounds; Oxidation-Reduction; Reactive Oxygen Species; Sulfhydryl Compounds; Tretinoin; Vitamins

Previous in vitro studies in our laboratory have shown that mancozeb (MZ) and maneb (MB), both widely used EBDC fungicides, are equipotent neurotoxicants that produce cell loss in mesencephalic dopaminergic and GABAergic cells after an acute 24h exposure. Mitochondrial uncoupling and inhibition were associated with fungicide exposure. Inhibition of mitochondrial respiration is known to increase free radical production. Here the mechanism(s) of neuronal damage associated with MZ exposure was further explored by determining the role that reactive oxygen species (ROS) played in toxicity. Damage to mesencephalic dopamine and GABA cell populations were significantly attenuated when carried out in the presence of ascorbate or SOD, indicative of a free radical-mediated contribution to toxicity. ROS generation monitored by hydrogen peroxide (H(2)O(2)) production using Amplex Red increased in a dose-dependent manner in response to MZ. Inhibition of intracellular catalase with aminotriazole had little effect on H(2)O(2) generation, whereas exogenously added catalase significantly reduced H(2)O(2) production, demonstrating a large extracellular contribution to ROS generation. Conversely, cells preloaded with the ROS indicator dye DCF showed significant MZ-induced ROS production, demonstrating an increase in intracellular ROS. Both the organic backbone of MZ as well as its associated Mn ion, but not Zn ion, were responsible and required for H(2)O(2) generation. The functionally diverse NADPH oxidase inhibitors, diphenylene iodonium chloride, apocynin, and 4-(2-aminoethyl)benzene-sulfonyl fluoride hydrochloride significantly attenuated H(2)O(2) production by MZ. In growth medium lacking cells, MZ produced little H(2)O(2), but enhanced H(2)O(2) generation when added with xanthine plus xanthine oxidase whereas, in cultured cells, allopurinol partially attenuated H(2)O(2) production by MZ. Minocycline, an inhibitor of microglial activation, modestly reduced H(2)O(2) formation in mesencephalic cells. In contrast, neuronal-enriched cultures or cultures treated with MAC-1-SAP to kill microglia, did not show an attenuation of ROS production. These findings demonstrate that Mn-containing EBDC fungicides such as MZ and MB can produce robust ROS generation that likely occurs via redox cycling with extracellular and intracellular oxidases. The findings further show that microglia may contribute to but are not required for ROS production by MZ.

Topics: Acetophenones; Allopurinol; Amitrole; Animals; Antioxidants; Ascorbic Acid; Catalase; Cells, Cultured; Dose-Response Relationship, Drug; Enzyme Inhibitors; Fungicides, Industrial; Hydrogen Peroxide; Maneb; Mesencephalon; Microglia; Minocycline; Molecular Structure; NADPH Oxidases; Neurons; Onium Compounds; Oxidation-Reduction; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Structure-Activity Relationship; Sulfones; Superoxide Dismutase; Time Factors; Xanthine Oxidase; Zineb

Few studies have examined the effect of acute pressure overload on endothelial function in the coronary microcirculation.. In instrumented conscious dogs with heart rate held constant, veratrine caused a cholinergic nitric oxide (NO)-dependent increase in coronary blood flow by 23+/-3 mL/min (Bezold-Jarisch reflex). Ten minutes after release of constriction of the ascending aorta to increase left ventricular (LV) systolic pressure to 214+/-5 mm Hg for 30 minutes, the veratrine-induced increase in coronary blood flow (7+/-1 mL/min) was reduced by 66% and remained depressed for 2 hours (ie, endothelial stunning [ES]). Nitrite production from isolated coronary microvessels during ES was not different from normal. Ascorbic acid (AA), losartan, or apocynin prevented ES. Myocardial oxygen consumption (MVO2) of LV tissue was measured in vitro in response to bradykinin with preincubation of angiotensin II for 30 minutes. Bradykinin (10(-4) mol/L)-induced reduction in MVO2 was reversed in a concentration-dependent manner by angiotensin II (38+/-1% versus 19+/-2% at 10(-8) mol/L) and restored by coincubation of AA (37+/-2%), tempol (33+/-2%), losartan (34+/-2%), or apocynin (36+/-1%). Exogenous NO-induced reduction in MVO2 was not altered by angiotensin II. Angiotensin II increased lucigenin-detectable superoxide anion in LV tissue in a manner that was inhibited by bradykinin, AA, tempol, losartan, or apocynin.. Endothelial stunning is caused by oxidant processes inhibited by ascorbate, and the activation of NAD(P)H oxidase by increased angiotensin II plays an important role in this process.

Topics: Acetophenones; Angiotensin II; Animals; Ascorbic Acid; Bradycardia; Bradykinin; Coronary Circulation; Cyclic N-Oxides; Dogs; Hypotension; Ligation; Losartan; Myocardial Stunning; Nitric Oxide; Oxidative Stress; Pressure; Reflex; Spin Labels; Superoxides; Veratrine