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1.
Leg Med (Tokyo) ; 67: 102393, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38217998

RESUMO

The term "planned complex suicide" refers to cases where two or more suicide methods are applied simultaneously. Plastic bag suffocation is a suicidal method commonly combined with self-poisoning by inhalation of volatile compounds or pharmacological substances at poisoning dosage. A 67-year-old woman was found dead on the couch. The head was wrapped in a plastic bag knotted at the front of the neck. No signs of struggle were present on the scene. In the fireplace, there were two blisters of acetaminophen/codeine phosphate tablets. Postmortem examination showed congestion of the face and the neck and pulmonary edema with patchy emphysema. There was no evidence of physical duress. Toxic levels of codeine were detected in the blood. The death was related to a complex suicide involving codeine overdose and asphyxia by plastic bag suffocation. The hypoxic/cardioinhibitory effects of plastic bag suffocation combined to codeine-induced deep reduction of respiratory rate, making the suicide hypothesis the more likely scenario. In order to assess what elements contribute to postmortem diagnosis in complex suicides with plastic bag suffocation, a review of the forensic literature published between 2002 and 2022 was performed. This article emphasizes the complexity of diagnosing deaths involving plastic bag suffocation in suicides, particularly when combined with other methods like inert gas inhalation or drug intake. It underscores the importance of comprehensive toxicological analyses, careful scene examination, and histological studies, not forgetting a thorough comparative analysis of the existing literature, to accurately determine the cause and manner of death in such cases.


Assuntos
Suicídio , Feminino , Humanos , Idoso , Asfixia/etiologia , Asfixia/patologia , Plásticos , Autopsia , Hipóxia
2.
J Forensic Sci ; 68(6): 2194-2199, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37565422

RESUMO

In December 2020, the World Health Organization (WHO) declared SARS-CoV2 a global pandemic. Home confinement, low social contacts, and fear of virus transmission played a major role as risk factors for suicides during the following period. Suicide pacts, in particular, showed a different pattern. A rare case of a triple suicide pact among members of the same family nucleus is presented. The victims were an elderly, severely ill woman and her adult children (a son and daughter), linked by a morbid relationship. The last time the family was seen alive was 40 days before the discovery. All corpses presented decompositional changes. After a full autopsy, the cause of death was determined to be a lethal intake of morphine for the mother and acute blood loss due to self-stabbing at the neck for the siblings. The younger woman was under the effects of a large amount of heparin. Toxicological analysis was positive for opioids and alcohol in both siblings. Suicide pacts have rarely been described during the COVID-19 pandemic. In the few cases reported, the victims were more often relatives than people in a romantic relationship. The involvement of three people is unusual, as is the use of different suicide methods among the victims. In the presented case, the elderly mother's imminent death from terminal cancer, her concern over dying in a nondomestic environment, and the siblings' fear of being alone likely led to the conception of the suicide pact. Social isolation and economic difficulties also played a contributing role.


Assuntos
COVID-19 , Suicídio , Humanos , Adulto , Feminino , Idoso , Pandemias , RNA Viral , SARS-CoV-2
3.
Curr Pharm Biotechnol ; 24(6): 719-727, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35713145

RESUMO

INTRODUCTION: The dynamism in the regulatory frameworks concerning the consumption of cannabinoids has placed their effects on cognitive and psychomotor skills at the center of the scientific debate. In consideration of the potential repercussions on public safety, particular attention has been focused on the impairment of driving skills, opening up the need to specifically regulate driving under the effects of cannabinoids. PHARMACOKINETICS: Both native cannabinoids and metabolites show a long positivity at low concentrations in the biological fluids, especially in the case of chronic consumption. Qualitative positivity to cannabinoids does not itself prove the presence of detrimental effects, which require the presence of active substances at relevant concentrations. Driving Skill Impairment: Multiple studies highlight a tetrahydrocannabinol (THC) concentration- based alteration of driving skills mainly affecting automatisms, whereas skills subjected to cognitive control are preserved up to higher dosages. The evidence relating to associations with other substances, chronic consumption and other cannabinoids, on the other hand, is still burdened by a high degree of uncertainty. Regulation Policies: Different models can be adopted in the regulation of driving under the effects of cannabinoids: sanctions can be applied in case of qualitative positivity, cannabinoids concentration above a defined threshold, or in presence of a demonstrated state of cognitive alteration. CONCLUSION: "Per se limit" with a quantitative THC cut-off between 3.5 and 5 ng/ml can currently be considered the most balanced choice. Finally, the analysis carried out allowed to identify pitfalls in both scientific and legislative fields for the improvement of safety policies.


Assuntos
Canabinoides , Cannabis , Alucinógenos , Cannabis/metabolismo , Canabinoides/análise , Dronabinol/análise , Agonistas de Receptores de Canabinoides , Políticas
4.
Int J Paleopathol ; 25: 56-61, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31071624

RESUMO

OBJECTIVE: To explore the possible etiology of multiple osteomata on a skull and long bones from an individual from a medieval site in Tuscany, Italy. MATERIALS: Human skeletal remains dating to the 10th-12th century AD from the parish church of S. Pietro in Pava, in the province of Siena (Tuscany, Central Italy). METHODS: Macroscopic and imaging analyses (Cone Beam Computed Tomography). RESULTS: Nine round-shaped new bone formations are observed on a female individual aged 40-50 years. The lesions have a smooth surface and range from 2.2-6 mm in diameter. CONCLUSIONS: Cone Beam Computed Tomography confirmed that the lesions were composed of compact bone. Macroscopic and radiological features suggest the presence of nonsyndromic multiple osteomata. SIGNIFICANCE: Single cranial osteomata are commonly observed in osteoarchaeological remains, but multiple osteomata are rare and might assist in our understanding of neoplastic conditions in the past. LIMITATIONS: The lack of soft tissues prevents the diagnosis of complex disorders, such as the Gardner syndrome, which is characterised by multiple osteomata and polyposis of the colon. SUGGESTIONS FOR FURTHER RESEARCH: Careful investigation and reporting of all neoplastic lesions in ancient human remains in order to increase our knowledge about the etiology in past human populations.


Assuntos
Neoplasias Ósseas/história , Osteoma/história , Adulto , Restos Mortais/diagnóstico por imagem , Restos Mortais/patologia , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Tomografia Computadorizada de Feixe Cônico , Feminino , História Medieval , Humanos , Itália , Pessoa de Meia-Idade , Osteoma/diagnóstico por imagem , Osteoma/patologia , Paleopatologia
6.
Res Vet Sci ; 123: 26-28, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30580232

RESUMO

The aim of this study was to explore the pharmacokinetics of the two main active compounds (THC and CBD) contained in the cannabis oil extract Bedrocan® in fasting and fed dogs. Bedrocan® (20% delta-9-tetrahydrocannabinol [THC] and 0.5% cannabidiol [CBD]) was administered at 1.5 and 0.037 mg/kg THC and CBD, respectively in fasted and fed dogs according to a 2 × 2 cross over study design. The quantification of the two active ingredients was performed by LC/MS. No detectable concentrations of CDB were found at any collection time. THC was quantifiable from 0.5 to 10 h, although there was large inter-subject variability. Fed dogs showed a longer absorption phase (Tmax 5 vs 1.25 h) and lower maximal blood concentration (7.1 vs 24 ng/mL) compared with the fasted group. A larger AUC was found in the fasted group; the relative oral bioavailability in fed animals was 48.22%.


Assuntos
Canabidiol/farmacocinética , Cães/metabolismo , Dronabinol/farmacocinética , Animais , Estudos Cross-Over , Feminino , Privação de Alimentos , Extratos Vegetais/farmacocinética , Distribuição Aleatória
7.
Biomed Chromatogr ; 32(4)2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29135039

RESUMO

A novel aqueous in situ derivatization procedure with propyl chloroformate (PCF) for the simultaneous, quantitative analysis of Δ9 -tetrahydrocannabinol (THC), 11-hydroxy-Δ9 -tetrahydrocannabinol (OH-THC) and 11-nor-Δ9 -tetrahydrocannabinol-carboxylic acid (THC-COOH) in human blood and urine is proposed. Unlike current methods based on the silylating agent [N,O-bis(trimethylsilyl)trifluoroacetamide] added in an anhydrous environment, this new proposed method allows the addition of the derivatizing agent (propyl chloroformate, PCF) directly to the deproteinized blood and recovery of the derivatives by liquid-liquid extraction. This novel method can be also used for hydrolyzed urine samples. It is faster than the traditional method involving a derivatization with trimethyloxonium tetrafluoroborate. The analytes are separated, detected and quantified by gas chromatography-mass spectrometry in selected ion monitoring mode (SIM). The method was validated in terms of selectivity, capacity of identification, limits of detection (LOD) and quantification (LOQ), carryover, linearity, intra-assay precision, inter-assay precision and accuracy. The LOD and LOQ in hydrolyzed urine were 0.5 and 1.3 ng/mL for THC and 1.2 and 2.6 ng/mL for THC-COOH, respectively. In blood, the LOD and LOQ were 0.2 and 0.5 ng/mL for THC, 0.2 and 0.6 ng/mL for OH-THC, and 0.9 and 2.4 ng/mL for THC-COOH, respectively. This method was applied to 35 urine samples and 50 blood samples resulting to be equivalent to the previously used ones with the advantage of a simpler method and faster sample processing time. We believe that this method will be a more convenient option for the routine analysis of cannabinoids in toxicological and forensic laboratories.


Assuntos
Dronabinol , Toxicologia Forense/métodos , Extração Líquido-Líquido/métodos , Dronabinol/análogos & derivados , Dronabinol/sangue , Dronabinol/isolamento & purificação , Dronabinol/urina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
8.
J Pharm Pharmacol ; 68(9): 1177-83, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27334686

RESUMO

OBJECTIVES: Carvacrol, a monoterpene widely present in nature, is commonly used in the food industry and in cosmetics, besides to possess a plethora of pharmacological properties, among these also in vitro vasorelaxing effects and in vivo hypotensive responses. Although in rat aortic rings carvacrol evoked a vasodilatation both in the presence and in the absence of endothelium, in preparations with intact endothelial layer its vasoactive response markedly improved. METHODS: This study aimed at investigating the mechanism of action responsible for the endothelial component of the carvacrol-induced vasorelaxing response observed in rat isolated aortic rings. KEY FINDINGS: Pharmacological characterization led us to exclude the involvement of NO pathway (neither L-NAME, NO biosynthesis inhibitor, nor ODQ, guanylate cyclase inhibitor, was able to modify the vascular effects of carvacrol) and of arachidonic acid cascade (no inhibitor intercepting the cascade influenced the endothelial-dependent vasodilatation of the monoterpene). Moreover, endothelial TRP channels were also not involved, as capsazepine did not antagonize vasorelaxing effect. Finally, endothelial potassium channels were considered as possible targets of carvacrol; indeed, two voltage-operated potassium (Kv) channel blockers, 4-aminopyridine and quinine, significantly reduced carvacrol potency and efficacy indices. CONCLUSIONS: Kv channels seem to be responsible for vascular effects of the monoterpene typical of Labiatae family.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Monoterpenos/farmacologia , Extratos Vegetais/farmacologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Aorta , Cimenos , Endotélio Vascular/fisiologia , Lamiaceae/química , Masculino , Óleos Voláteis/farmacologia , Potássio/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Ratos Wistar
9.
J Forensic Sci ; 60(5): 1355-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26300490

RESUMO

A sensitive and reliable method for extraction and quantification of benzoylecgonine (BZE) and cocaine (COC) in urine is presented. Propyl-chloroformate was used as derivatizing agent, and it was directly added to the urine sample: the propyl derivative and COC were then recovered by liquid-liquid extraction procedure. Gas chromatography-mass spectrometry was used to detect the analytes in selected ion monitoring mode. The method proved to be precise for BZE and COC both in term of intraday and interday analysis, with a coefficient of variation (CV)<6%. Limits of detection (LOD) were 2.7 ng/mL for BZE and 1.4 ng/mL for COC. The calibration curve showed a linear relationship for BZE and COC (r2>0.999 and >0.997, respectively) within the range investigated. The method, applied to thirty authentic samples, showed to be very simple, fast, and reliable, so it can be easily applied in routine analysis for the quantification of BZE and COC in urine samples.


Assuntos
Cocaína/análogos & derivados , Cocaína/urina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Entorpecentes/urina , Toxicologia Forense , Formiatos/química , Humanos , Limite de Detecção
10.
Eur J Pharmacol ; 760: 1-6, 2015 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-25891369

RESUMO

This study evaluated the relationship between the plasma concentration of l-methadone and response to methadone in real-world patients, in order to identify a minimum plasma concentration above which methadone treatment is effective. Ninety-four patients with opioid dependence under maintenance methadone treatment were consecutively recruited. Response was defined as negative urine analyses in the three weeks prior to the blood sampling. The percentage of participants with a plasma l-methadone concentration between 100 and 250 ng/ml was 54.2% among those with a methadone dosage ≥60 mg/day. Plasma l-methadone concentrations were significantly higher in patients with negative urine analyses compared with those with positive urine analyses (median 93 vs. 77 ng/ml, Mann-Whitney test, P<0.05). Above plasma l-methadone concentrations of 200 ng/ml no heroin use was reported and urine analyses were negative. Moreover, above concentrations of 250 ng/ml craving was absent. Examination of demographic correlates of treatment outcome indicated that older age, a stable job and being married were protective against the use of heroin. Mean plasma l-methadone concentration was significantly lower in patients who used cannabis compared with those who did not use cannabis, after adjusting for methadone dosage. In conclusion our results identify specific cut-offs for plasma l-methadone concentrations about which therapeutic response is observed and provide new evidence that therapeutic response is associated with patient׳s demographic characteristics. This underscores the need to monitor plasma methadone concentrations as part of Drug Addiction Services routine practice, in order to provide an objective framework for changing the methadone dosage.


Assuntos
Metadona/sangue , Metadona/uso terapêutico , Tratamento de Substituição de Opiáceos/métodos , Transtornos Relacionados ao Uso de Opioides/sangue , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Adulto , Estudos Transversais , Dependência de Heroína/sangue , Dependência de Heroína/diagnóstico , Dependência de Heroína/tratamento farmacológico , Humanos , Metadona/química , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Opioides/diagnóstico , Estereoisomerismo , Resultado do Tratamento , Adulto Jovem
11.
J Forensic Sci ; 58(2): 552-5, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23278468

RESUMO

We describe a case of an acute lethal poisoning with hydrocarbons resulting from massive accidental inhalation of gasoline vapors. The victim, a 50-year-old man was found unconscious inside a control room for the transport of unleaded fuel. Complete autopsy was performed and showed evidence of congestion and edema of the lungs. Toxicological investigation was therefore fundamental to confirm exposure to fumes of gasoline. Both venous and arterial blood showed high values of volatiles in particular for benzene (39.0 and 30.4 µg/mL, respectively), toluene (23.7 and 20.4 µg/mL), and xylene isomers (29.8 and 19.3 µg/mL). The relatively low values found in the lungs are consistent with the fact that the subject, during the rescue, underwent orotracheal intubation followed by resuscitation techniques, while the low concentrations for all substances found in urine and kidneys could point to a death that occurred in a very short time after first contact with the fumes of gasoline.


Assuntos
Poluentes Atmosféricos/intoxicação , Gasolina/intoxicação , Benzeno/análise , Humanos , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Tolueno/sangue , Volatilização , Xilenos/sangue
12.
J Anal Toxicol ; 36(8): 548-59, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22933659

RESUMO

Heroin is one of the most dangerous abused drugs in the world. Tramadol is an additive recently found at high concentration levels in street heroin seizures in Egypt. This substance could affect the usual analytical method for the detection of heroin and metabolites, as well as the pharmacokinetic and disposition of single analytes. One shortfall regarding this issue is present in the literature. This study describes a validated, simple, sensitive and selective method to determine tramadol, O-desmethyltramadol, 6-acetylmorphine and free morphine in the blood, brain, liver and kidney of Wistar rats, intraperitoneally treated with a combination of heroin and tramadol (10 and 70 mg/kg, respectively) using liquid-liquid extraction and gas chromatography-mass spectrometry detection. The calibration curves of tramadol, O-desmethyltramadol and 6-acetylmorphine in blood were linear in the concentration range from 25-5,000 ng/mL and morphine was found in the concentration range 50-5,000 ng/mL. The analytes were detected in all tested matrices, except 6-acetylmorphine, which was not detected in liver. The highest concentrations of tramadol and O-desmethyltramadol were observed in kidney (22,9381 and 28,498 ng/g), while 6-acetylmorphine and morphine were found at the highest levels in brain (3,280 and 3,899 ng/g, respectively). The present method is simple, rapid and sensitive and can be used to study the pharmacokinetics, disposition and interaction of these drugs in several animal models.


Assuntos
Analgésicos Opioides/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Heroína/análise , Drogas Ilícitas/análise , Detecção do Abuso de Substâncias/métodos , Tramadol/análise , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/farmacocinética , Animais , Encéfalo/metabolismo , Química Encefálica , Quimioterapia Combinada , Heroína/administração & dosagem , Heroína/farmacocinética , Drogas Ilícitas/farmacocinética , Injeções Intraperitoneais , Rim/química , Rim/metabolismo , Fígado/química , Fígado/metabolismo , Morfina/análise , Morfina/metabolismo , Derivados da Morfina/análise , Derivados da Morfina/metabolismo , Ratos , Ratos Wistar , Distribuição Tecidual , Tramadol/administração & dosagem , Tramadol/análogos & derivados , Tramadol/metabolismo , Tramadol/farmacocinética
13.
J Forensic Sci ; 57(5): 1384-7, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22607089

RESUMO

This article reports the determination of phenobarbital in the mummified body of a 56-year-old man found completely mummified 10 years after his death. When alive, he was being treated for epilepsy with phenobarbital, and the recent analyses, performed with both immunochemical techniques and gas chromatography with mass spectrometry (GC-MS), have revealed the presence of this substance in various tissues: the mean content of barbiturate in the mummified liver tissue was 93 µg/g, 216 µg/g in the heart, 17 µg/g in the lungs, 12 µg/g in muscles, and 31 µg/g in the skin. Preliminary screening tests with immunochemical techniques to evaluate the presence of other drugs were also performed. The sample resulted negative for all substances tested. Phenobarbital can be identified and quantified thanks to its excellent chemical stability and a hypothesis of what the concentrations in the fresh tissue could have been has also been reported.


Assuntos
Anticonvulsivantes/análise , Múmias/patologia , Fenobarbital/análise , Toxicologia Forense , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Fígado/química , Pulmão/química , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/química , Miocárdio/química , Pele/química , Extração em Fase Sólida
14.
Angiogenesis ; 15(2): 275-86, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22382585

RESUMO

AIMS: To evaluate UFT and cyclophosphamide (CTX) based metronomic chemotherapy plus celecoxib (CXB) for the treatment of patients with heavily pre-treated advanced gastrointestinal malignancies. METHODS: Thirty-eight patients received 500 mg/mq(2) CTX i.v bolus on day 1 and, from day 2, 50 mg/day CTX p.o. plus 100 mg/twice a day UFT p.o. and 200 mg/twice a day CXB p.o. Tegafur, 5-FU, 5-FUH(2), GHB and uracil pharmacokinetics were assessed. Plasma vascular endothelial growth factor (VEGF), soluble VE-cadherin (sVE-C) and thrombospondin-1 (TSP-1) levels were detected by ELISA and real-time PCR of CD133 gene expression on peripheral blood mononuclear cell was also performed. RESULTS: Seventeen patients (45%) obtained stable disease (SD) with a median duration of 5.8 ms (range, 4.2-7.4). Median progression free survival (PFS) and overall survival (OS) were 2.7 ms (95% CI, 1.6-3.9 ms) and 7.1 ms (95% CI, 4.3-9.9 ms), respectively. No toxicities of grade >1 were observed. Pharmacokinetics of 27 patients (13/14, SD/progressive disease, PD) after the first treatment of UFT revealed that 5-FU AUC and C(max) values greater than 1.313 h × µg/ml and 0.501 µg/ml, respectively, were statistically correlated with stabilization of disease and prolonged PFS/OS. VEGF and sVE-C plasma levels were greater in the PD group when compared to SD group. CD133 expression increased only in the PD patients. CONCLUSION: Metronomic UFT and CTX with CXB in heavily pre-treated gastrointestinal patients were well tolerated and associated with interesting activity. Potential predictive pharmacokinetic parameters and pharmacodynamic biomarkers have been found.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Ciclofosfamida/farmacocinética , Neoplasias Gastrointestinais/tratamento farmacológico , Pirazóis/farmacocinética , Sulfonamidas/farmacocinética , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Celecoxib , Ciclofosfamida/administração & dosagem , Feminino , Neoplasias Gastrointestinais/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Pirazóis/administração & dosagem , Sulfonamidas/administração & dosagem , Tegafur/administração & dosagem , Tegafur/farmacocinética , Uracila/administração & dosagem , Uracila/farmacocinética , Fator A de Crescimento do Endotélio Vascular/sangue
15.
Fitoterapia ; 76(5): 481-3, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15967593

RESUMO

The essential oils obtained from fifteen relevant and commonly used plants belonging to Cruciferae, Lamiaceae, Lauraceae, Apiaceae, and Zingiberaceae were screened using an in vitro model of peroxynitrite-induced tyrosine nitration. Almost complete inhibition of 3-nitrotyrosine formation (91% at 300 microg/ml) was achieved only with the essential oil obtained from the leaves of Laurus nobilis. 1,8-Cineol, accounting for a 50% of this essential oil, which resulted as inactive in this model, thus evidencing a major role for the minor volatile compounds present in the leaves.


Assuntos
Laurus , Fitoterapia , Óleos de Plantas/farmacologia , Tirosina/química , Humanos , Nitratos/química , Ácido Peroxinitroso/química , Folhas de Planta , Óleos de Plantas/química
16.
J Agric Food Chem ; 53(12): 4762-5, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15941312

RESUMO

The essential oil obtained from the bark of Cinnamomum zeylanicum Blume (Lauraceae) and three of its main components, eugenol, (E)-cinnamaldehyde, and linalool (representing 82.5% of the total composition), were tested in two in vitro models of peroxynitrite-induced nitration and lipid peroxidation. The essential oil and eugenol showed very powerful activities, decreasing 3-nitrotyrosine formation with IC50 values of 18.4 microg/mL and 46.7 microM, respectively (reference compound, ascorbic acid, 71.3 microg/mL and 405.0 microM) and also inhibiting the peroxynitrite-induced lipid peroxidation showing an IC50 of 2.0 microg/mL and 13.1 microM, respectively, against 59.0 microg/mL (235.5 microM) of the reference compound Trolox. On the contrary, (E)-cinnamaldehyde and linalool were completely inactive.


Assuntos
Cinnamomum zeylanicum/química , Eugenol/farmacologia , Óleos Voláteis/farmacologia , Ácido Peroxinitroso/farmacologia , Tirosina/análogos & derivados , Animais , Cromatografia Líquida de Alta Pressão , Peroxidação de Lipídeos/efeitos dos fármacos , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Nitratos/química , Oxirredução , Ratos , Tirosina/química
17.
Naunyn Schmiedebergs Arch Pharmacol ; 370(4): 290-8, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15378228

RESUMO

A flavonoid-rich diet has been associated with a lower incidence of cardiovascular diseases, probably because of the antioxidant and vasoactive properties of flavonoids. Indeed, many flavonoids show vasorelaxing properties, due to different and often not yet completely clarified mechanisms of action. Among them, the activation of vascular potassium channels has been indicated as a possible pathway, accounting, at least in part, for the vasodilatory action of some flavonoid derivatives, such as apigenin and dioclein. Therefore, this work aims at evaluating, on in vitro isolated rat aortic rings, the endothelium-independent vasorelaxing effects of a number of flavonoid derivatives, to identify a possible activation of calcium-activated and/or ATP-sensitive potassium channels and to indicate some possible structure-activity relationships. Among the several flavonoids submitted to the pharmacological assay, only baicalein and quercetagetin were almost completely ineffective, while quercetin, hesperidin, quercitrin and rhoifolin exhibited only a partial vasorelaxing effect. On the contrary, acacetin, apigenin, chrysin, hesperetin, luteolin, pinocembrin, 4'-hydroxyflavanone, 5-hydroxyflavone, 5-methoxyflavone, 6-hydroxyflavanone and 7-hydroxyflavone, belonging to the chemical classes of flavones and flavanones, showed full vasorelaxing effects. The vasodilatory activity of hesperetin, luteolin, 5-hydroxyflavone and 7-hydroxyflavone were antagonised by tetraethylammonium chloride, indicating the possible involvement of calcium-activated potassium channels. Moreover, iberiotoxin clearly antagonised the effects of 5-hydroxyflavone, indicating the probable importance of a structural requirement (the hydroxy group in position 5) for a possible interaction with large-conductance, calcium-activated potassium channels. Finally, glibenclamide inhibited the vasorelaxing action of luteolin and 5-hydroxyflavone, suggesting that ATP-sensitive potassium channels may also be involved in their mechanism of action.


Assuntos
Flavonoides/farmacologia , Canais de Potássio/fisiologia , Vasodilatação/efeitos dos fármacos , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Relação Dose-Resposta a Droga , Flavonoides/química , Técnicas In Vitro , Masculino , Ratos , Ratos Wistar , Vasodilatação/fisiologia
18.
J Ethnopharmacol ; 91(2-3): 263-6, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15120449

RESUMO

The methanolic extract of leaves of Michelia figo Spreng. (Magnoliaceae), as well as several purified fractions, showed a concentration-dependent vasorelaxing effect on aortic rings endothelium-deprived and pre-contracted by norepinephrine (NE). For further pharmacological investigation on the mechanism of action, the fraction S4 was selected, since it showed the best vasodilator properties. The pharmacological effect was not produced through the stimulation of cyclooxygenase, adenyl cyclase, or guanylyl cyclase, since selective inhibitors did not prevent the fraction S4-induced effects. Moreover, the vasorelaxing effect of the fraction was resistant to the block of nifedipine-sensitive Ca(2+) channels. The fraction S4 (10(-4) g/ml) produced a shift towards the right of the concentration-contractile response curve to NE, in normal conditions, and the shift was more evident in Ca(2+)-free Tyrode solution, suggesting an action on intracellular Ca(2+)-channels. The vasodilator action of fraction S4 on NE pre-contracted rings was not prevented by cyclopiazonic acid (blocker of Ca(2+)/ATPase), which excludes a role for mechanisms involving the storage of Ca(2+) in the sarcoplasmic reticulum. The reduction of the contraction elicited by caffeine, an opener of ryanodine-sensitive receptors, suggests that the fraction S4 of Michelia figo leaves could produce the vasorelaxing response by the blockade of ryanodine-sensitive Ca(2+) channels of the sarcoplasmic reticulum.


Assuntos
Aorta/efeitos dos fármacos , Magnoliaceae , Fitoterapia , Extratos Vegetais/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Aorta/fisiologia , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Masculino , Norepinefrina , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Folhas de Planta , Ratos , Ratos Wistar , Vasodilatadores/administração & dosagem , Vasodilatadores/uso terapêutico
19.
Planta Med ; 69(10): 885-92, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14648389

RESUMO

Large-conductance calcium-activated potassium channels, also known as BK or Maxi-K channels, occur in many types of cell, including neurons and myocytes, where they play an essential role in the regulation of cell excitability and function. These properties open a possible role for BK-activators (also called BK-openers) and/or BK-blockers as effective therapeutic agents for different neurological, urological, respiratory and cardiovascular diseases. The synthetic benzimidazolone derivatives NS004 and NS1619 are the pioneer BK-activators and have represented the reference models which led to the design of several novel and heterogeneous synthetic BK-openers, while very few synthetic BK-blockers have been reported. Even today, the research towards identifying new BK-modulating agents is proceeding with great impetus and is giving an ever-increasing number of new molecules. Among these, also a handsome number of natural BK-modulator compounds, belonging to different structural classes, has appeared in the literature. The goal of this paper is to provide a possible simple classification of the broad structural heterogeneity of the natural BK-activating agents (terpenes, phenols, flavonoids) and blockers (alkaloids and peptides), and a concise overview of their chemical and pharmacological properties as well as potential therapeutic applications.


Assuntos
Benzimidazóis/farmacologia , Fitoterapia , Plantas Medicinais , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio Cálcio-Ativados/efeitos dos fármacos , Benzimidazóis/química , Clorofenóis/química , Clorofenóis/farmacologia , Humanos , Bloqueadores dos Canais de Potássio/química , Canais de Potássio Cálcio-Ativados/agonistas , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores
20.
Planta Med ; 69(8): 770-2, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14531031

RESUMO

Gentiana kochiana Perr. et Song. (Gentianaceae), a plant used in the traditional medicine of Tuscany (Italy) as antihypertensive remedy, exerts a vasodilator action on in vitro aortic rings that is probably linked to the blocking of the ryanodine-sensitive Ca++ channels. In the present study, three known xanthones were isolated from the crude methanolic extract of the roots: gentiacaulein, gentiakochianin, and swertiaperennin. The first two showed a vasorelaxing activity in rat aortic preparations, pre-contracted by 3 microM norepinephrine (pIC50 = 5.00 +/- 0.032 for gentiacaulein, pIC50 = 4.95 +/- 0.068 for gentiakochianin), 20 mM KCl (pIC50 = 4.90 +/- 0.15 for gentiacaulein; 4.59 +/- 0.069 for gentiakochianin), or 5 mM caffeine; on the contrary, in the same conditions, swertiaperennin did not show any vasodilator effect. In conclusion, gentiacaulein and gentiakochianin seem to be the compounds responsible for the vasorelaxing properties of the crude extract of Gentiana kochiana roots.


Assuntos
Anti-Hipertensivos/farmacologia , Aorta/efeitos dos fármacos , Gentiana , Fitoterapia , Xantonas/farmacologia , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/uso terapêutico , Canais de Cálcio/efeitos dos fármacos , Relação Dose-Resposta a Droga , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Raízes de Plantas , Ratos , Ratos Wistar , Vasodilatadores/administração & dosagem , Vasodilatadores/farmacologia , Vasodilatadores/uso terapêutico , Xantonas/administração & dosagem , Xantonas/uso terapêutico
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