16 results on '"DalBó S"'
Search Results
2. P.1.d.001 Interoceptive olfactory fear conditioning acquisition and expression is affected by a glucocorticoid agonist
- Author
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Cavalli, J., primary, DalBó, S., additional, Bertoglio, L.J., additional, and Carobrez, A.P., additional
- Published
- 2012
- Full Text
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3. Antinociceptive effect of Croton celtidifolius Baill (Euphorbiaceae)
- Author
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Nardi GM, Dalbó S, Monache FD, Pizzolatti MG, and Ribeiro-do-Valle RM
- Abstract
Croton celtidifolius Baill (Euphorbiaceae) is a tree found in the Atlantic forest of southern Brazil. This plant is used in folk medicine for the treatment of several inflammatory diseases, leukaemia, ulcers and other pathologies. Previous studies demonstrated anti-inflammatory and antioxidant activities and the objective of this work was to investigate a possible antinociceptive action of ethanolic extract of Croton celtidifolius bark (EE) and ethyl acetate fraction (EAF), n-butanol fraction (FBuOH), and aqueous fraction (FAq) obtained from EE. Two standard rodent models of pain were employed for this investigation, the writhing test and the formalin test. In the writhing test, the pre-treatment with EE significantly reduced the writhing induced by 0.6% acetic acid injection and its effect persisted for 4h. In the formalin test, the pre-treatment with EAF caused marked and dose-related inhibition of formalin-induced licking in mice in the first phase, while pre-treatment with EAF, FBuOH and FAq had a similar effect in the second phase, when given by intraperitoneal (i.p.) and orally (p.o.) route. However, given by i.p. route, the effect of fractions was about three to five-fold more potent in inhibiting licking than when administered by p.o. route. EE presented an antinociceptive effect only in the second phase, when given by i.p. or p.o. route. The oedema caused by formalin was significantly reduced in animals treated i.p. with EAF, FBuOH and FAq. Under the same experimental conditions, in animals treated with sub-fractions derived from EAF only the 63 sub-fraction significantly reduced nociception in both phases and oedema caused by formalin. The results obtained suggest that Croton celtidifolius possesses antinociceptive properties since the EE, fractions and a sub-fraction significantly reduced the writhing induced by acetic acid and the nociception in both phases of the formalin test. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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4. Cardiac hyporesponsiveness in severe sepsis is associated with nitric oxide-dependent activation of G protein receptor kinase.
- Author
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Dal-Secco D, DalBó S, Lautherbach NES, Gava FN, Celes MRN, Benedet PO, Souza AH, Akinaga J, Lima V, Silva KP, Kiguti LRA, Rossi MA, Kettelhut IC, Pupo AS, Cunha FQ, and Assreuy J
- Subjects
- Animals, Enzyme Activation, Female, G-Protein-Coupled Receptor Kinase 2 genetics, Heart Failure etiology, Heart Failure pathology, In Vitro Techniques, Mice, Mice, Inbred C57BL, Mice, Knockout, Myocytes, Cardiac pathology, Sepsis complications, Signal Transduction, G-Protein-Coupled Receptor Kinase 2 metabolism, Heart Failure metabolism, Myocytes, Cardiac metabolism, Nitric Oxide metabolism, Sepsis metabolism
- Abstract
G protein-coupled receptor kinase isoform 2 (GRK2) has a critical role in physiological and pharmacological responses to endogenous and exogenous substances. Sepsis causes an important cardiovascular dysfunction in which nitric oxide (NO) has a relevant role. The present study aimed to assess the putative effect of inducible NO synthase (NOS2)-derived NO on the activity of GRK2 in the context of septic cardiac dysfunction. C57BL/6 mice were submitted to severe septic injury by cecal ligation and puncture (CLP). Heart function was assessed by isolated and perfused heart, echocardiography, and β-adrenergic receptor binding. GRK2 was determined by immunofluorescence and Western blot analysis in the heart and isolated cardiac myocytes. Sepsis increased NOS2 expression in the heart, increased plasma nitrite + nitrate levels, and reduced isoproterenol-induced isolated ventricle contraction, whole heart tension development, and β-adrenergic receptor density. Treatment with 1400W or with GRK2 inhibitor prevented CLP-induced cardiac hyporesponsiveness 12 and 24 h after CLP. Increased labeling of total and phosphorylated GRK2 was detected in hearts after CLP. With treatment of 1400W or in hearts taken from septic NOS2 knockout mice, the activation of GRK2 was reduced. 1400W or GRK2 inhibitor reduced mortality, improved echocardiographic cardiac parameters, and prevented organ damage. Therefore, during sepsis, NOS2-derived NO increases GRK2, which leads to a reduction in β-adrenergic receptor density, contributing to the heart dysfunction. Isolated cardiac myocyte data indicate that NO acts through the soluble guanylyl cyclase/cGMP/PKG pathway. GRK2 inhibition may be a potential therapeutic target in sepsis-induced cardiac dysfunction. NEW & NOTEWORTHY The main novelty presented here is to show that septic shock induces cardiac hyporesponsiveness to isoproterenol by a mechanism dependent on nitric oxide and mediated by G protein-coupled receptor kinase isoform 2. Therefore, G protein-coupled receptor kinase isoform 2 inhibition may be a potential therapeutic target in sepsis-induced cardiac dysfunction., (Copyright © 2017 the American Physiological Society.)
- Published
- 2017
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5. Popular medicinal uses of Calea uniflora Less. (Asteraceae) and its contribution to the study of Brazilian medicinal plants.
- Author
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Ramos LS, Cardoso PS, Freitas MD, Paghan R, Borges MS, Citadini-Zanette V, Barlow JW, Amaral PA, and Dalbó S
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- Brazil, Health Knowledge, Attitudes, Practice, Humans, Surveys and Questionnaires, Asteraceae, Phytotherapy statistics & numerical data, Plants, Medicinal chemistry
- Abstract
Calea uniflora Less. is widely used in southern Santa Catarina (Brazil), but there are no scientific studies which support its use. Then, this study was proposed to determine of the percentage use of C. uniflora in a city of southern Brazil and documentation of the knowledge that the population has about this species. The survey was conducted with semi-structured interviews using a questionnaire applied to 372 participants. In analyzing the results, it was observed that of the 94.1% who recognized C. uniflora, 74.3% utilize it as a medicinal plant and 65.4% of such knowledge originates in childhood, mainly through the family (84.6%). 93% reported using inflorescences macerated in alcohol or rum; this extract is generally used topically for wound healing and muscle pain. Furthermore, some reported using small quantities of this extract orally to treat cold and flu. Regarding effectiveness and safety, 97% stated an improvement in symptoms with the use of the plant, while 98.5% stated that it has no toxicity. In light of these results, future phytochemical, pharmacological and toxicological analyses should be designed in order to ensure rational and safe use of this species.
- Published
- 2016
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6. Experimental periodontitis promotes transient vascular inflammation and endothelial dysfunction.
- Author
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Brito LC, DalBó S, Striechen TM, Farias JM, Olchanheski LR Jr, Mendes RT, Vellosa JC, Fávero GM, Sordi R, Assreuy J, Santos FA, and Fernandes D
- Subjects
- Acetylcholine pharmacology, Alveolar Bone Loss physiopathology, Analysis of Variance, Animals, Biomarkers analysis, C-Reactive Protein analysis, Endothelium metabolism, Inflammation metabolism, Inflammation physiopathology, Interleukin-6 blood, Male, Mesenteric Arteries physiopathology, Microscopy, Fluorescence, Nitric Oxide Synthase analysis, Nitroprusside pharmacology, Periodontitis metabolism, Phenylephrine pharmacology, Rats, Rats, Wistar, Superoxides analysis, Endothelium drug effects, Inflammation complications, Mesenteric Arteries drug effects, Periodontitis etiology, Vasodilation drug effects
- Abstract
Objectives: This study aimed to evaluate the systemic inflammatory response and cardiovascular changes induced by experimental periodontitis in rats., Design: Experimental periodontitis was induced by placing a cotton ligature around the cervix of both sides of mandibular first molars and maxillary second molars in each male rat. Sham-operated rats had the ligature removed immediately after the procedure. Seven, 14 or 28 days after procedure, the effects of acetylcholine, sodium nitroprusside and phenylephrine were evaluated on blood pressure, aortic rings and isolated and perfused mesenteric bed. The blood was obtained for plasma Interleukin-6 (IL-6), C-reactive protein (CRP) and lipid evaluation. The mesenteric vessels were obtained to evaluate superoxide production and nitric oxide synthase 3 (NOS-3) expression., Results: Ligature induced periodontitis reduced endothelium-dependent vasodilatation, a hallmark of endothelial dysfunction. This effect was associated with an increase in systemic inflammatory markers (IL-6 and CRP), worsens on lipid profile, increased vascular superoxide production and reduced NOS-3 expression. It is interesting to note that many of these effects were transitory., Conclusion: Periodontitis induced a transient systemic and vascular inflammation which leads to endothelial dysfunction, an initial step for cardiovascular diseases. Moreover, the animal model of periodontitis used here may represent a valuable tool for studying the relationship between periodontitis and endothelial dysfunction., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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7. Anti-atherogenic effects of a phenol-rich fraction from Brazilian red wine (Vitis labrusca L.) in hypercholesterolemic low-density lipoprotein receptor knockout mice.
- Author
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Hort MA, Schuldt EZ, Bet AC, DalBó S, Siqueira JM, Ianssen C, Abatepaulo F, de Souza HP, Veleirinho B, Maraschin M, and Ribeiro-do-Valle RM
- Subjects
- Acetates pharmacology, Animals, Arteries physiopathology, Atherosclerosis physiopathology, Brazil, Cholesterol, HDL blood, Cholesterol, LDL blood, Diet, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Models, Animal, Receptors, LDL genetics, Receptors, LDL metabolism, Triglycerides blood, Vasodilation drug effects, Atherosclerosis drug therapy, Hypercholesterolemia drug therapy, Phenols pharmacology, Receptors, LDL drug effects, Wine analysis
- Abstract
Moderate wine intake (i.e., 1-2 glasses of wine a day) is associated with a reduced risk of morbidity and mortality from cardiovascular disease. The aim of this study was to evaluate the anti-atherosclerotic effects of a nonalcoholic ethyl acetate fraction (EAF) from a South Brazilian red wine obtained from Vitis labrusca grapes. Experiments were carried out on low-density lipoprotein (LDL) receptor knockout (LDLr⁻/⁻) mice, which were subjected to a hypercholesterolemic diet and treated with doses of EAF (3, 10, and 30 mg/kg) for 12 weeks. At the end of the treatment, the level of plasma lipids, the vascular reactivity, and the atherosclerotic lesions were evaluated. Our results demonstrated that the treatment with EAF at 3 mg/kg significantly decreased total cholesterol, triglycerides, and LDL plus very low-density lipoprotein levels compared with control hypercholesterolemic mice. The treatment of mice with EAF at 3 mg/kg also preserved the vasodilatation induced by acetylcholine on isolated thoracic aorta from hypercholesterolemic LDLr⁻/⁻ mice. This result is in agreement with the degree of lipid deposit on arteries. Taken together, the results show for the first time that the lowest concentration of an EAF obtained from a red wine produced in southern Brazil significantly reduced the progression of atherosclerosis in mice.
- Published
- 2012
- Full Text
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8. The autoimmune nature of post-infarct myocardial healing: oral tolerance to cardiac antigens as a novel strategy to improve cardiac healing.
- Author
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Ramos GC, Dalbó S, Leite DP, Goldfeder E, Carvalho CR, Vaz NM, and Assreuy J
- Subjects
- Animals, Autoantigens administration & dosage, Cytokines biosynthesis, Disease Models, Animal, Female, Forkhead Transcription Factors metabolism, Isoproterenol adverse effects, Lymphocyte Activation immunology, Myocardial Infarction chemically induced, Myocardial Infarction pathology, Rats, Rats, Wistar, Autoantigens immunology, Autoimmunity, Immune Tolerance immunology, Myocardial Infarction immunology, Myocardium immunology, Myocardium pathology, Wound Healing immunology
- Abstract
Following a myocardial infarction, lymphocytes have been suggested to react with the damaged heart tissue, which can impair proper tissue healing. In the present work, we investigate whether ingestion of a myocardial homogenate and the consequent development of immunological tolerance can modify the course of post-infarction myocardial repair. Infarction-like myocardial lesions were induced in Wistar rats by injecting high doses of isoproterenol. The healing process was evaluated morphologically and functionally for 60 days. Cardiac function was evaluated using isolated and perfused heart (Langendorff) preparations. At day 14 after isoproterenol treatment, lymphocytes from the mediastinal lymph nodes proliferated when exposed in vitro to myocardial homogenate. Moreover, TNF-α, IFN-γ and CCL-5, but not FOXP3+ expression, was increased in draining lymph nodes in isoproterenol-injured animals, indicating that the observed lymphocyte population that proliferated in response to cardiac components presented a pro-inflammatory and pro-fibrotic profile. In contrast, lymphocytes from draining lymph nodes of rats given a heart homogenate by gavage 7 days before isoproterenol did not proliferate. Furthermore, the group rendered tolerant expressed cardiac FOXP3+ earlier than did the control group, and showed a milder inflammatory infiltrate, lower MMP-9 expression, less collagen deposition, and improved cardiac performance when compared to animals that received only isoproterenol administration. The present findings suggest that the establishment of oral tolerance to heart components prior to myocardial infarction may drive the cardiac healing process to proceed with less inflammation and fibrosis, thus preserving contractile organ function.
- Published
- 2012
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9. Proanthocyanidin-rich fraction from Croton celtidifolius Baill confers neuroprotection in the intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine rat model of Parkinson's disease.
- Author
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Moreira EL, Rial D, Aguiar AS Jr, Figueiredo CP, Siqueira JM, DalBó S, Horst H, de Oliveira J, Mancini G, dos Santos TS, Villarinho JG, Pinheiro FV, Marino-Neto J, Ferreira J, De Bem AF, Latini A, Pizzolatti MG, Ribeiro-do-Valle RM, and Prediger RD
- Subjects
- Administration, Intranasal, Animals, Disease Models, Animal, Male, Neuroprotective Agents administration & dosage, Plant Extracts administration & dosage, Proanthocyanidins therapeutic use, Rats, Rats, Wistar, Croton chemistry, Neuroprotective Agents pharmacology, Parkinsonian Disorders drug therapy, Plant Extracts pharmacology, Proanthocyanidins pharmacology
- Abstract
We have recently demonstrated that rodents treated intranasally with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) suffered impairments in olfactory, cognitive and motor functions associated with time-dependent disruption of dopaminergic neurotransmission in different brain structures conceivably analogous to those observed during different stages of Parkinson's disease (PD). On the other hand, the proanthocyanidin-rich fraction (PRF) obtained from the bark of Croton celtidifolius Baill (Euphorbiaceae), a tree frequently found in the Atlantic forest in south Brazil, has been described to have several neurobiological activities including antioxidant and anti-inflammatory properties, which may be of interest in the treatment of PD. The present data indicated that the pretreatment with PRF (10 mg/kg, i.p.) during five consecutive days was able to prevent mitochondrial complex-I inhibition in the striatum and olfactory bulb, as well as a decrease of the enzyme tyrosine hydroxylase expression in the olfactory bulb and substantia nigra of rats infused with a single intranasal administration of MPTP (1 mg/nostril). Moreover, pretreatment with PRF was found to attenuate the short-term social memory deficits, depressive-like behavior and reduction of locomotor activity observed at different periods after intranasal MPTP administration in rats. Altogether, the present findings provide strong evidence that PRF from C. celtidifolius may represent a promising therapeutic tool in PD, thus being able to prevent both motor and non-motor early symptoms of PD, together with its neuroprotective potential.
- Published
- 2010
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10. Antioxidant and hepatoprotective effects of Cyathea phalerata Mart. (Cyatheaceae).
- Author
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Hort MA, Dalbó S, Brighente IM, Pizzolatti MG, Pedrosa RC, and Ribeiro-do-Valle RM
- Subjects
- Animals, Antioxidants administration & dosage, Antioxidants therapeutic use, Carbon Tetrachloride, Chemical and Drug Induced Liver Injury drug therapy, Chemical and Drug Induced Liver Injury metabolism, DNA Damage, Dose-Response Relationship, Drug, Free Radical Scavengers administration & dosage, Free Radical Scavengers therapeutic use, In Vitro Techniques, Lipid Peroxidation drug effects, Liver metabolism, Male, Mice, Phytotherapy, Plant Extracts administration & dosage, Plant Extracts pharmacology, Plant Extracts therapeutic use, Plant Stems, Protein Carbonylation drug effects, Rats, Antioxidants pharmacology, Ferns, Free Radical Scavengers pharmacology, Liver drug effects, Oxidative Stress drug effects
- Abstract
The present study investigated the antioxidant properties of Cyathea phalerata Mart. (Cyatheaceae) using in vitro and in vivo assays. The in vitro antioxidant potential of the crude extract (CE), precipitate (PPT), aqueous fraction (AQF), n-butanolic fraction (BUF) and ethyl acetate fraction (EAF) from C. phalerata was evaluated through the scavenging of diphenyl-1-picryl-hydrazyl-hydrate (DPPH), superoxide anion (O(2)(*-)) (nitroblue tetrazolium assay) and hydroxyl radicals (OH(*)) (deoxyribose assay), and lipid peroxidation in rat liver homogenate. In these assays, it was observed that EAF had marked antioxidant potential, especially as a scavenger of the OH(*) radical and in inhibiting lipid peroxidation. The in vivo evaluation of oxidative stress (DNA fragmentation, membrane lipoperoxidation and carbonyl protein formation) and the antioxidant defenses (concentration of reduced glutathione, as well as catalase and glutathione S-transferase activities) were measured in mice pre-treated with EAF (10, 30 or 100 mg/kg, orally) and later exposed to carbon tetrachloride (CCl(4)). The EAF decreased thiobarbituric acid reactive substances levels, DNA damage and carbonyl protein contents, and increased catalase and glutathione S-transferase activities. Based on these results, it is concluded that the EAF from C. phalerata protects liver from oxidative stress induced by CCl(4) in mice and these effects are probably related to the antioxidant activity associated with the free radical scavenging property of this fraction.
- Published
- 2008
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11. Activation of endothelial nitric oxide synthase by proanthocyanidin-rich fraction from Croton celtidifolius (Euphorbiaceae): involvement of extracellular calcium influx in rat thoracic aorta.
- Author
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DalBó S, Goulart S, Horst H, Pizzolatti MG, and Ribeiro-do-Valle RM
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- Animals, Dose-Response Relationship, Drug, Enzyme Activation, Ethylmaleimide pharmacology, In Vitro Techniques, Male, Nitric Oxide physiology, Nitroarginine pharmacology, Rats, Rats, Wistar, Type C Phospholipases physiology, Aorta, Thoracic metabolism, Calcium metabolism, Croton chemistry, Nitric Oxide Synthase Type III metabolism, Proanthocyanidins pharmacology
- Abstract
The present study investigates the mechanisms related to the endogenous nitric oxide synthase (eNOS) activation in the relaxant effects of a proanthocyanidin-rich fraction (PRF), obtained from Croton celtidifolius Baill barks, in rat thoracic aorta rings with endothelium. In vessels pre-contracted with phenylephrine (Phe), PRF (0.1 - 100 microg/mL) induced a concentration-dependent relaxation. This effect was significantly reduced by endothelium denudation, by N(omega)-nitro-L-arginine, and by 1H[1,2,3]oxadiazolo[4,3-alpha]quinoxalin. However, the vasorelaxant effect was not altered by indomethacin, atropine, tetraethylammonium, and charybdotoxin plus apamin. In thoracic aorta rings pre-contracted with phorbol-12,13-dibuyrate, PRF also induced a concentration-dependent relaxation. The PRF-induced relaxation disappeared in the absence of extracellular calcium in the medium and decreased significantly in the presence of lanthanum. A sulfhydryl alkylating agent, N-ethylmaleimide, and a phospholipase C (PLC) blocker, neomycin, significantly decreased PRF-induced vasorelaxation. In vessels pre-contracted with Phe, the PRF-induced vasorelaxant effect was not altered by quinacrine and ONO-RS-082, genistein and thyrphostin A-23, GF109203, and pertussis toxin and cholera toxin. The results suggest that the PRF-induced vasorelaxant effect is endothelium-dependent and involves the NO/cGMP pathway. We hypothesize that the activation of eNOS is due to an increase of intracellular calcium derived from PLC activation and an N-ethylmaleimide sensitive pathway.
- Published
- 2008
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12. Mechanisms underlying the vasorelaxant effect induced by proanthocyanidin-rich fraction from Croton celtidifolius in rat small resistance arteries.
- Author
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DalBó S, Moreira EG, Brandão FC, Horst H, Pizzolatti MG, Micke GA, and Ribeiro-do-Valle RM
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- Animals, Cyclic GMP physiology, Endothelium, Vascular drug effects, Endothelium, Vascular physiology, In Vitro Techniques, Male, Mesenteric Artery, Superior physiology, Nitric Oxide physiology, Plant Bark chemistry, Potassium Channels, Calcium-Activated physiology, Rats, Rats, Wistar, Croton chemistry, Mesenteric Artery, Superior drug effects, Proanthocyanidins pharmacology, Vasodilator Agents pharmacology
- Abstract
Proanthocyanidins are condensed tannins present in fruits, vegetables, and flowers, consumed in the human diet. These compounds are believed to decrease coronary heart disease. The present study was designed to investigate the relaxing effects of a proanthocyanidin-rich fraction (PRF) obtained from Croton celtidifolius BAILL (Euphorbiaceae) barks in rat mesenteric arterial bed (MAB) and isolated mesenteric artery (MA). In the MAB pre-contracted with phenylephrine (Phe), PRF (0.1 - 100 microg) induced a concentration-dependent relaxation of 73% (compared to the control). This effect was significantly reduced by the nitric oxide (NO) synthase inhibitor N(omega)-nitro-L-arginine (L-NOARG) or high K(+) solution and completely abolished in vessels perfused with KCl plus L-NOARG. However, the vasorelaxant effect was not altered by indomethacin, atropine, yohimbine, pyrilamine, or K(+)-channel blockers: BaCl(2), glibenclamide, ouabain, and 4-aminopyridine. In isolated MA pre-contracted with Phe, PRF also induced a concentration-dependent relaxation (0.1 - 30 microg/mL), which was in turn inhibited by endothelial removal, guanylyl cyclase inhibitor 1H[1,2,3]oxadiazolo[4,3-alpha]quinoxalin, charybdotoxin (ChTx), and ChTx plus apamin. Moreover, the relaxant effect was not altered by HOE140 and apamin given alone. The present study demonstrates that the vasorelaxing effect of PRF is dependent upon the NO-cGMP pathway in combination with hyperpolarization due to activation of Ca(2+)-dependent K(+) channels.
- Published
- 2008
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13. Analysis of the antinociceptive effect of the proanthocyanidin-rich fraction obtained from Croton celtidifolius barks: evidence for a role of the dopaminergic system.
- Author
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DalBó S, Jürgensen S, Horst H, Soethe DN, Santos AR, Pizzolatti MG, and Ribeiro-do-Valle RM
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- Animals, Arginine pharmacology, Male, Mice, Nitric Oxide physiology, Prazosin pharmacology, Sulpiride pharmacology, Yohimbine pharmacology, Analgesics pharmacology, Croton chemistry, Plant Extracts pharmacology, Proanthocyanidins pharmacology, Receptors, Dopamine D2 physiology
- Abstract
In a previous study, we demonstrated the antinociceptive effect of 63SF, a proanthocyanidin-rich fraction obtained from Croton celtidifolius barks, in chemical and thermal behavioural models of pain in mice. The current study now investigate the possible mechanisms underlying the antinociceptive activity of 63SF in the formalin test, by using drugs which interfere with systems that are implicated in descending control of nociception. The antinociceptive effect of 63SF (11 mg/kg, i.p., given 30 min prior to 2.5% formalin) was not altered by pre-treatment of animals 45-50 min beforehand with either prazosin (alpha(1)-adrenergic antagonist; 0.15 mg/kg, i.p.), yohimbine (alpha(2)-adrenergic antagonist; 0.15 mg/kg, i.p.), ketanserin (5-HT(2A)-receptor antagonist; 1.0 mg/kg, i.p.), or l-arginine (substrate for NO synthase, 600 mg/kg, i.p.). On the other hand, treatment with sulpiride, an antagonist of dopaminergic D(2)-receptors (1.0 mg/kg, i.p., 45 min of pre-treatment), reversed the antinociceptive activity of 63SF. Pre-treatment of animals with reserpine (5 mg/kg, i.p., 24 h beforehand) did not alter the antinociceptive effect of 63SF. The current results support the view that the 63SF exerts antinociceptive effects by enhancing the activity of descending control, possibly by direct stimulation of dopaminergic D(2) receptors.
- Published
- 2006
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14. Involvement of 5-HT2 receptors in the antinociceptive effect of Uncaria tomentosa.
- Author
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Jürgensen S, Dalbó S, Angers P, Santos AR, and Ribeiro-do-Valle RM
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- Acetic Acid, Animals, Arginine pharmacology, Atropine pharmacology, Behavior, Animal drug effects, Capsaicin, Dose-Response Relationship, Drug, Formaldehyde, Ketanserin pharmacology, Male, Mice, Motor Activity drug effects, Naltrexone pharmacology, Pain chemically induced, Pain prevention & control, Pain Measurement methods, Phytotherapy, Prazosin pharmacology, Reserpine pharmacology, Serotonin 5-HT2 Receptor Antagonists, Serotonin Antagonists pharmacology, Yohimbine pharmacology, Analgesics pharmacology, Cat's Claw, Plant Preparations pharmacology, Receptors, Serotonin, 5-HT2 physiology
- Abstract
Uncaria tomentosa (Willd.) DC (Rubiaceae) is a vine that grows in the Amazon rainforest. Its bark decoctions are used by Peruvian Indians to treat several diseases. Chemically, it consists mainly of oxindole alkaloids. An industrial fraction of U. tomentosa (UT fraction), containing 95% oxindole alkaloids, was used in this study in order to characterize its antinociceptive activity in chemical (acetic acid-induced abdominal writhing, formalin and capsaicin tests) and thermal (tail-flick and hot-plate tests) models of nociception in mice. UT fraction given by the i.p. route dose-dependently suppressed the behavioural response to the chemical stimuli in the models indicated and increased latencies in the thermal stimuli models. The antinociception caused by UT fraction in the formalin test was significantly attenuated by i.p. treatment of mice with ketanserin (5-HT2 receptor antagonist), but was not affected by naltrexone (opioid receptor antagonist), atropine (a nonselective muscarinic antagonist), l-arginine (precursor of nitric oxide), prazosin (alpha1-adrenoceptor antagonist), yohimbine (alpha2-adrenoceptor antagonist), and reserpine (a monoamine depleter). Together, these results indicate that UT fraction produces dose-related antinociception in several models of chemical and thermal pain through mechanisms that involve an interaction with 5-HT2 receptors.
- Published
- 2005
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15. Antinociceptive effect of proanthocyanidins from Croton celtidifolius bark.
- Author
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DalBó S, Jürgensen S, Horst H, Ruzza AA, Soethe DN, Santos AR, Pizzolatti MG, and Ribeiro-do-Valle RM
- Subjects
- Administration, Oral, Animals, Chromatography, High Pressure Liquid, Dose-Response Relationship, Drug, Injections, Intraperitoneal, Male, Mice, Plant Bark, Plant Extracts therapeutic use, Analgesics therapeutic use, Croton, Pain drug therapy, Phytotherapy, Proanthocyanidins therapeutic use
- Abstract
The chemical composition of the chromatography 63 subfraction (63SF) from the ethyl acetate soluble fraction of the crude extract of Croton celtidifolius bark presented a high content of total proanthocyanidins (75.0+/-2.3%). HPLC analysis of 63SF revealed a dimeric profile (e.g.catechin-(4alpha-->8)-catechin and gallocatechin-(4alpha-->8)-catechin) and polymeric proanthocyanidins. In pharmacological investigations, 63SF administered intraperitoneally exhibited dose-dependent antinociceptive activity against several chemical stimuli, including the intraperitoneal injection of acetic acid (ID50 (the dose of 63SF which was able to reduce the nociceptive response by 50% relative to the control value)=0.9 (0.5-1.6)) and the intraplantar injection of capsaicin (ID50=13.0 (10.0-17.0)), glutamate (ID50=4.0 (2.0-7.0)) and formalin (ID50 first phase=36.0 (24.0-53.0) and late phase=11.0 (8.0-14.0)). 63SF administered orally exhibited an antinociceptive effect in the formalin test (ID50 first phase=125.0 (89.0-177.0) and late phase=65.0 (33.0-95.0)). In the same test, 63SF was effective when given soon after the first phase, as well as exhibiting therapeutic activity. Furthermore, 63SF was effective in models of thermal nociception including tail-flick and hot-plate tests. When the mice were treated in the neonatal period with capsaicin, the antinociceptive effect of 63SF in the first phase of the formalin test was abolished, but pretreatment with naltrexone did not change the antinociceptive effect of 63SF. Together, these results provide evidence that 63SF exerted a pronounced systemic antinociception against chemical (acetic acid, formalin, glutamate and capsaicin tests) and thermal (hot-plate and tail-flick tests) nociceptive models of pain in mice at a dose that did not interfere with the locomotor activity. The mechanism by which this sub-fraction produced antinociception remains unclear, but it is unlikely to involve the activation of the opioid system. However, unmyelinated C-fibres sensitive to treatment with capsaicin are likely to participate in antinociception caused by 63SF.
- Published
- 2005
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16. Antinociceptive effects of peripheral benzodiazepine receptors.
- Author
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DalBó S, Nardi GM, Ferrara P, Ribeiro-do-Valle RM, and Farges RC
- Subjects
- Aminoglutethimide pharmacology, Analgesics administration & dosage, Animals, Benzodiazepinones administration & dosage, Dose-Response Relationship, Drug, Enzyme Inhibitors pharmacology, Foot, Formaldehyde, Injections, Injections, Intraventricular, Injections, Spinal, Isoquinolines administration & dosage, Male, Mice, Steroids physiology, Analgesics pharmacology, Benzodiazepinones pharmacology, Isoquinolines pharmacology, Pain Measurement drug effects, Peripheral Nervous System drug effects, Receptors, GABA-A drug effects
- Abstract
Pretreatment of mice with Ro5-4864 or PK11195 inhibited the first- and second-phase responses in the formalin test and this effect was significantly reversed by aminoglutethimide, an inhibitor of pregnenolone synthesis, suggesting that the antinociceptive effect of the peripheral-type benzodiazepine receptor ligands is dependent on steroid formation. Doses of Ro5-4864 that did not produce an antinociceptive effect when injected by the intraperitoneal route presented an analgesic effect, if infected by the intracerebroventricular, intrathecal or intraplantar routes. PK11195 pretreatments with intrathecal, intracerebroventricular or intraplantar doses had no effect in the formalin test. These results suggest that the antinociceptive effect of Ro5-4864 reflects the influence of this ligand on steroid production not only in many nonneuronal peripheral tissues but also in the nervous system, while the antinociceptive action of PK11195 may be due to the stimulation of steroid synthesis only in nonnervous tissues., (Copyright 2004 S. Karger AG, Basel)
- Published
- 2004
- Full Text
- View/download PDF
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