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1.
Toxicol Lett ; 350: 261-266, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371141

RESUMO

The ingestion of Nerium oleander and Thevetia peruviana are common causes for poisoning in Southeast Asia. All parts of the oleander shrub contain cardiac glycosides of the cardenolide type. These glycosides act via inhibition of a Na+/K+-ATPase which might cause severe arrhythmia and subsequent death in oleander-poisoned patients. The current study uses human induced pluripotent stem cells derived cardiomyocytes (hiPSC-CM) in a microelectrode array (MEA) system to assess the cardiac effects of neriifolin, oleandrin, digitoxigenin, peruvoside and thevetin A from the oleander plant. Digoxin was used as established reference compound. All tested compounds showed a corrected field potential duration (FPDc) shortening and was the lowest for 600 nM digitoxigenin with -36.9 ± 1.2 %. Next to the dose-dependent pro-arrhythmic potential, a complete beat arrest of the spontaneously beating hiPSC-CM was observed at a concentration of 300 nM for neriifolin, 600 nM for oleandrin and 1000 nM for digitoxigenin and peruvoside. Thevetin A did not cause arrhythmia up to a final concentration of 1000 nM. Thus, it was possible to establish a cardiac effect rank order of the tested substances: neriifolin > oleandrin > digitoxigenin = peruvoside > digoxin > thevetin A.


Assuntos
Cardenolídeos/toxicidade , Glicosídeos Cardíacos/toxicidade , Células Cultivadas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Nerium/toxicidade , Intoxicação por Plantas/fisiopatologia , Glicosídeos Cardíacos/química , Humanos , Nerium/química
2.
Neurotoxicology ; 78: 21-28, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32035075

RESUMO

Nerium oleander Linn. is an Apocynaceae shrub which is among the most toxic ornamental plants. Although seizures are one of the symptoms associated with N. Oleander poisoning in humans, only a few studies are available on the behavioural and electrophysiological alterations caused by this plant poisoning. This study aimed at providing a thorough description of the electroencephalographic (EEG) and electromyographic (EMG) profiles throughout the experimental poisoning of Wistar rats (200-250 g) using ethanolic extract of N. oleander (EENO). Further, seizure control was assessed using different anticonvulsants. Male Wistar rat's behaviour was assessed upon EENO (150 mg/kg) administration and the animals were evaluated for muscle and neural activities through EMG and EEG recordings, respectively. The behavioural test showed two distinct phases of CNS activity: Phase I - myorelaxation and depression, and Phase II - excitability (agitated behaviour and seizures). Such phases were consistent with the EEG and EMG tracing patterns attained. Within the first 400 s of the recordings, during Phase I, the EMG showed no tracing amplitude variation. Later, the tracing pattern was changed and an intensification of the muscle contraction power in higher frequencies was observed during Phase II. The EEG showed initially a slight flattening in the tracings with a reduction in the intensity of the signal as per spectrogram of frequency attained. Thereafter, during Phase II, much higher amplitude tracings could be noted with an intensification of the signal, compatible with seizures. Seizure control was evaluated using four agents: phenytoin, phenobarbital, diazepam and scopolamine (at 10 mg/kg in all cases). While scopolamine was not effective in the seizure control, diazepam was the most efficient drug for the attenuation of the poisoning. Our results indicate the possibility of including phenytoin, phenobarbital and diazepam, mainly the latter, in the poisoning therapeutic protocol, including for those individuals who could be more susceptible to the poisoning by Nerium oleander as in the case of epileptic patients.


Assuntos
Anticonvulsivantes/administração & dosagem , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Músculo Masseter/efeitos dos fármacos , Músculo Masseter/fisiopatologia , Nerium , Extratos Vegetais/toxicidade , Animais , Eletroencefalografia , Eletromiografia , Masculino , Intoxicação por Plantas/fisiopatologia , Ratos Wistar , Convulsões/prevenção & controle
4.
Clin Toxicol (Phila) ; 56(9): 841-845, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29490507

RESUMO

INTRODUCTION: Steroidal alkaloids are found in plants of the genus Veratrum. Their toxicity manifests as gastrointestinal symptoms followed by a Bezold-Jarisch reflex: hypopnea, hypotension, and bradycardia. Some Veratrum steroidal alkaloids are also teratogens interfering with the hedgehog-2 signaling pathway, which causes cyclopsia and holoprosencephaly. We present a case of accidental poisoning from Veratrum parviflorum mistaken for the edible Allium tricoccum (ramps, wild leek). CASE HISTORY: A 27-year-old man and his 25-year-old wife presented to the emergency department with nausea, vomiting, hypotension, and bradycardia after foraging and ingesting plants that they believed to be a local native species of wild leek. METHODS: We collected and analyzed the implicated fresh plant material and both patients' serum/plasma. We used liquid chromatography-mass spectroscopy and high-resolution electrospray ionization time of flight tandem mass spectrometry to extract and characterize steroidal alkaloids from the foraged plant and patients' serum. RESULTS: Our V. parviflorum samples contained verazine, veratramine, veratridine, and cyclopamine. DISCUSSION: Steroidal alkaloids have been previously isolated from Veratrum viride and Veratrum album and toxicity has been reported mainly from V. album species. CONCLUSION: V. parviflorum toxicity manifests with gastrointestinal and cardiac symptoms. Treatment is symptomatic and supportive as with previous case reports of toxicity with other Veratrum species.


Assuntos
Antieméticos/uso terapêutico , Gastroenteropatias/tratamento farmacológico , Intoxicação por Plantas/tratamento farmacológico , Intoxicação por Plantas/fisiopatologia , Alcaloides de Veratrum/intoxicação , Veratrum/intoxicação , Vômito/tratamento farmacológico , Adulto , Feminino , Gastroenteropatias/etiologia , Georgia , Humanos , Masculino , Resultado do Tratamento , Vômito/etiologia
5.
J Trop Pediatr ; 62(6): 487-489, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27240665

RESUMO

Cleistanthus collinus, also known as Oduvanthalai in Tamil, is the most commonly encountered plant poison in southern India. The leaves are used for poisoning humans (suicide or homicide) and animals (cattle and fish) and as an abortifacient, especially in rural south India. Although this poisoning is commonly reported in adults, data regarding the use of N-acetylcysteine in pediatric poisoning is lacking. We report two previously healthy male siblings of pediatric age group who ingested the liquid extracted from crushed leaves of this plant given to them by their mother as a means of deliberate harm. Both patients developed distal renal tubular acidosis, with hypokalemia. The younger sibling also developed myocardial toxicity. Other significant findings noted include hypocalcemia, hypomagnesemia and elevated liver enzymes. Both patients received supportive care along with N-acetylcysteine infusion, and showed complete recovery within 10 days.


Assuntos
Acetilcisteína/administração & dosagem , Injúria Renal Aguda/induzido quimicamente , Glicosídeos/intoxicação , Túbulos Renais/fisiopatologia , Extratos Vegetais/intoxicação , Intoxicação por Plantas/fisiopatologia , Criança , Humanos , Concentração de Íons de Hidrogênio , Hipopotassemia/induzido quimicamente , Masculino , Tentativa de Suicídio , Resultado do Tratamento , Vômito/induzido quimicamente
6.
Toxicon ; 118: 91-4, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27125469

RESUMO

In the semiarid region of Brazil, in areas with vegetation composed mainly of Poincianella pyramidalis, several cases of congenital malformation and reproductive losses were observed in goats and sheep from 2012 to 2014. To determine the teratogenic effect of P. pyramidalis, two groups of eight goats each were used. Goats from Group 1 received fresh P. pyramidalis, harvested daily, as the only roughage during the whole breeding and pregnancy period. Goats in Group 2 (control) received Cynodon dactylon (tifton) hay free choice. Ultrasound examination for pregnancy diagnosis was performed every 28 days. Four goats from Group 1 were pregnant on day 28 but not on day 56, suggesting embryonic death or abortion. Another goat from Group 1 died at day 70 of pregnancy, and the fetuses exhibited micrognathia. The other three goats bore six kids, three of which showed bone malformations in the limbs, spine, ribs, sternum, and head, including arthrogryposis, scoliosis and micrognathia. One kid also showed hypoplasia of the left pulmonary lobes. In the control group, all goats bore a total of 13 kids and none of them exhibited malformations. These results demonstrated that P. pyramidalis causes congenital malformations and other reproductive losses in goats.


Assuntos
Anormalidades Induzidas por Medicamentos/veterinária , Aborto Animal/induzido quimicamente , Caesalpinia/toxicidade , Reabsorção do Feto/veterinária , Doenças das Cabras/induzido quimicamente , Doenças das Cabras/etiologia , Intoxicação por Plantas/veterinária , Complicações na Gravidez/veterinária , Animais , Artrogripose/induzido quimicamente , Artrogripose/veterinária , Brasil , Cynodon , Feminino , Reabsorção do Feto/induzido quimicamente , Doenças das Cabras/fisiopatologia , Cabras , Micrognatismo/induzido quimicamente , Micrognatismo/veterinária , Componentes Aéreos da Planta/toxicidade , Intoxicação por Plantas/fisiopatologia , Gravidez , Complicações na Gravidez/fisiopatologia , Escoliose/induzido quimicamente , Escoliose/veterinária
7.
Toxicon ; 99: 125-9, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25817002

RESUMO

BACKGROUND: Toxalbumins are natural plant toxins purported to be highly toxic. The purpose was to evaluate toxalbumin exposures reported to U.S. poison centers to determine plants involved and their toxicities. METHODS: A retrospective review of National Poison Data System data on acute toxalbumin exposures with known outcomes from 2000 through 2011 was performed. RESULTS: There were 1164 exposures. The majority involved one route (1135; 97.5%), mostly ingestions (904; 79.7%) or dermal (166; 14.3%). Most patients developed no effects (694; 59.6%) or minor effects (374; 32.1%). Moderate or major effects occurred in 8.3% with 66.6% ingestions and 23.9% dermal. There were no deaths. Exposures to the plants Ricinus communis and Robinia pseudoacacia were most common (33.8% and 32.9%, respectively), with gastrointestinal effects from R. communis (vomiting 19.6%, diarrhea 8.9%, nausea 7.9%) and dermal effects from R. pseudoacacia (puncture 28.7%, dermal irritation/pain 27.9%, and edema 13.3%). CONCLUSIONS: While toxalbumin plant exposures were generally well-tolerated, continued evaluation of risk is warranted since plants were primarily identified by the public. Major effects occurred in under 1% of cases overall, and not at all following unintentional ingestions. These findings should help allay concerns that unintentional ingestions of toxalbumin plants by young children will cause serious toxicity and possibly death.


Assuntos
Lectinas de Plantas/toxicidade , Intoxicação por Plantas/etiologia , Ricina/toxicidade , Ricinus communis/toxicidade , Robinia/toxicidade , Toxinas Biológicas/toxicidade , Doença Aguda , Adulto , Doenças Assintomáticas/epidemiologia , Doenças Assintomáticas/terapia , Criança , Bases de Dados Factuais , Dermatite de Contato/epidemiologia , Dermatite de Contato/etiologia , Dermatite de Contato/fisiopatologia , Dermatite de Contato/terapia , Feminino , Gastroenterite/etiologia , Humanos , Masculino , Neurotoxinas/toxicidade , Intoxicação por Plantas/epidemiologia , Intoxicação por Plantas/fisiopatologia , Intoxicação por Plantas/terapia , Centros de Controle de Intoxicações , Estudos Retrospectivos , Estados Unidos/epidemiologia
8.
Toxicon ; 99: 36-43, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25772859

RESUMO

Larkspurs (Delphinium spp.) are poisonous plants on rangelands throughout the Western United States and Canada. Larkspur-induced poisoning in cattle is due to norditerpene alkaloids that are represented by two main structural groups of norditerpene alkaloids, the N-(methylsuccinimido) anthranoyllycoctonine type (MSAL-type) and the non-MSAL type. Information on the alkaloid composition and resulting toxicity in mice and cattle is lacking for a number of Delphinium species, including Delphinium stachydeum. The objective of this study was to determine the alkaloid composition of D. stachydeum and to characterize its relative toxicity in mice and cattle compared to two reference species Delphinium barbeyi and Delphinium occidentale. D. stachydeum contains the non-MSAL-type alkaloids but not the MSAL-type alkaloids. D. stachydeum was less toxic than D. barbeyi and D. occidentale in the mouse model. D. stachydeum was less toxic than the MSAL-containing D. barbeyi but much more toxic than the non-MSAL-containing D. occidentale in cattle as measured by heart rate and time of exercise. These results indicate that predictions of Delphinium toxicity can't be accurately made based solely on results from the mouse model or the absence of the MSAL-type alkaloids in the plant.


Assuntos
Alcaloides/toxicidade , Doenças dos Bovinos/fisiopatologia , Delphinium/toxicidade , Componentes Aéreos da Planta/toxicidade , Extratos Vegetais/toxicidade , Intoxicação por Plantas/veterinária , Toxinas Biológicas/toxicidade , Alcaloides/análise , Alcaloides/química , Alcaloides/isolamento & purificação , Animais , Bovinos , Doenças dos Bovinos/etiologia , Delphinium/química , Delphinium/crescimento & desenvolvimento , Diterpenos/análise , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/toxicidade , Humanos , Coxeadura Animal/etiologia , Dose Letal Mediana , Masculino , Camundongos , Debilidade Muscular/etiologia , Nevada , Oregon , Componentes Aéreos da Planta/química , Componentes Aéreos da Planta/crescimento & desenvolvimento , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Intoxicação por Plantas/etiologia , Intoxicação por Plantas/fisiopatologia , Especificidade da Espécie , Taquicardia/etiologia , Toxinas Biológicas/análise , Toxinas Biológicas/química , Toxinas Biológicas/isolamento & purificação , Tremor/etiologia , Utah
9.
J Med Toxicol ; 11(1): 141-3, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25252802

RESUMO

Oleander poisoning typically results in cardiac arrhythmias, hyperkalemia, and gastrointestinal irritation, and can be fatal. Oleander extracts have also been studied experimentally as hypoglycemic agents. Here, we describe a dog with confirmed oleander toxicosis presenting with classical symptoms and also hypoglycemia. After excluding other likely causes of hypoglycemia, the finding was attributed to oleander toxicosis, which has not been previously reported in dogs. A 7-year-old female spayed Maltese was presented to the emergency service after ingesting oleander leaves. Toxicosis was confirmed by measurement of digoxin using a competitive binding immunoassay, patient level 0.7 ng/mL (0.9 nmol/L) 24-h post-ingestion. Clinical symptoms included vomiting, cardiac arrhythmia, mild hyperkalemia, and hypoglycemia. Treatment was successful with aggressive supportive care, and the dog was discharged from the hospital after 48 h and made a full recovery. This case reviews the presentation and treatment of oleander toxicity but also highlights possible effects of oleander on blood sugar in dogs. Hypoglycemia in this dog, attributed to oleander poisoning, is interesting as it supports experimental research into hypoglycemic properties of oleander extracts.


Assuntos
Doenças do Cão/induzido quimicamente , Hipoglicemia/veterinária , Nerium/toxicidade , Folhas de Planta/toxicidade , Intoxicação por Plantas/veterinária , Animais , Animais Endogâmicos , Terapia Combinada/veterinária , Reações Cruzadas , Digoxina/sangue , Doenças do Cão/sangue , Doenças do Cão/fisiopatologia , Doenças do Cão/terapia , Cães , Tratamento de Emergência/veterinária , Feminino , Hospitais Veterinários , Hipoglicemia/induzido quimicamente , Hipoglicemia/etiologia , Imunoensaio/veterinária , Intoxicação por Plantas/sangue , Intoxicação por Plantas/fisiopatologia , Intoxicação por Plantas/terapia , Resultado do Tratamento
11.
Trop Doct ; 41(2): 113-5, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21262956

RESUMO

Many herbomineral preparations are currently being used as therapeutic remedies for common ailments. Commonly known cardiotoxic herbs are Aconitum ferox (aconite), Areca catechu (betel nut), Thevetia peruviana (yellow oleander) and Cleistanus collinus (oduvan). Herbs mixed with lead, copper and/or mercury are known to be highly toxic. They produce cardiac arrhythmias, mainly ventricular ectopics, ventricular tachycardia and various degrees of arterioventricular (AV) blocks. We report 12 such successive cases where the patients developed vague feelings of discomfort, dizziness, chest discomfort and ventricular arrhythmias following herbal drug ingestion which warranted the immediate discontinuation of the drug. Three of the patients died. This paper emphasizes the risk of unsupervised use of herbomineral preparations by patients who believe that the remedies are always 'safe' and the urgent necessity for the pharmacognostic identification of the constituent herbs, their toxicological studies, uniform nomenclature, authenticity and standardization of plants and their parts before advocating them for therapeutic use.


Assuntos
Arritmias Cardíacas/etiologia , Cardiopatias/induzido quimicamente , Intoxicação por Plantas/etiologia , Intoxicação por Plantas/terapia , Plantas Medicinais/efeitos adversos , Plantas Tóxicas/intoxicação , Adolescente , Adulto , Química Farmacêutica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intoxicação por Plantas/fisiopatologia , Adulto Jovem
12.
Toxicon ; 56(3): 273-81, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20438743

RESUMO

Nerium oleander (common oleander) and Thevetia peruviana (yellow oleander) are potentially lethal plants after ingestion. Poisoning by these plants is a common toxicological emergency in tropical and subtropical parts of the world and intentional self-harm using T. peruviana is prevalent in South Asian countries, especially India and Sri Lanka. All parts of these plants are toxic, and contain a variety of cardiac glycosides including neriifolin, thevetin A, thevetin B, and oleandrin. Ingestion of either oleander results in nausea, vomiting, abdominal pain, diarrhoea, dysrhythmias, and hyperkalemia. In most cases, clinical management of poisoning by either N. oleander or T. peruviana involves administration of activated charcoal and supportive care. Digoxin specific Fab fragments are an effective treatment of acute intoxication by either species. However, where limited economic resources restrict the use of such Fab fragments, treatment of severely poisoned patients is difficult. Data from case reports and clinical studies were reviewed to identify treatments supported by evidence for the management of poisoning by N. oleander and T. peruviana.


Assuntos
Nerium/intoxicação , Intoxicação por Plantas/diagnóstico , Intoxicação por Plantas/terapia , Plantas Tóxicas/intoxicação , Humanos , Intoxicação por Plantas/fisiopatologia
13.
Hum Exp Toxicol ; 29(5): 427-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20068013

RESUMO

A 27-year-old female nurse intravenously injected 5 mL of cigarette soakage solution that contained approximately 5.7 mg nicotine, in a suicidal attempt. Clinical manifestations consisted of nausea, palpitation, abdominal pain, repeated vomiting, and diarrhea. She remained fully conscious during this episode. About 7 hours later, she visited emergency department on foot and received fluid infusion for dehydration. She fully recovered at night of the day. This is the first documented report of acute nicotine poisoning due to intravenous injection of cigarette soakage in humans. Signs and symptoms appeared immediately after the injection, but this case seemed to be relatively mild in terms of clinical manifestation. The elimination half-life of nicotine seems to be short, that is, less than 1 hour. Therefore, if initial treatment is appropriate and the patient can survive acute phase of nicotine poisoning, prognosis is good.


Assuntos
Nicotiana/química , Nicotina/intoxicação , Intoxicação por Plantas/etiologia , Adulto , Feminino , Hidratação , Meia-Vida , Humanos , Injeções Intravenosas , Nicotina/farmacocinética , Extratos Vegetais/química , Extratos Vegetais/farmacocinética , Extratos Vegetais/intoxicação , Intoxicação por Plantas/fisiopatologia , Intoxicação por Plantas/terapia , Tentativa de Suicídio
14.
Hum Exp Toxicol ; 29(5): 431-4, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20106940

RESUMO

Two previously healthy women developed nausea, vomiting, headache and dizziness for several days, a massive hair loss about 2 weeks later and a discoloration of the fingernails. Detailed diagnostic procedures did not reveal any pathological results. Therapeutic measures did not show any effect. Thallium and arsenic were within normal range in plasma. Delayed quantitative determination of selenium in blood, however revealed toxic values (in case I: 479 microg/L of serum, 8 weeks after ingestion, and in case II 300 microg/L of serum, 9 weeks after ingestion). In retrospect, a relation to the ingestion of paradise nuts could be established.


Assuntos
Lecythidaceae/química , Nozes/intoxicação , Intoxicação por Plantas/etiologia , Selênio/intoxicação , Árvores , Doença Aguda , Adulto , Alopecia/induzido quimicamente , Alopecia/patologia , Tontura/induzido quimicamente , Tontura/fisiopatologia , Feminino , Cefaleia/induzido quimicamente , Cefaleia/fisiopatologia , Humanos , Pessoa de Meia-Idade , Unhas/efeitos dos fármacos , Unhas/patologia , Náusea/induzido quimicamente , Náusea/fisiopatologia , Nozes/química , Intoxicação por Plantas/sangue , Intoxicação por Plantas/fisiopatologia , Selênio/sangue , Vômito/induzido quimicamente , Vômito/fisiopatologia
15.
Clin Toxicol (Phila) ; 47(4): 270-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19514873

RESUMO

INTRODUCTION: Water hemlock, which encompasses a range of species divided across two genera (Cicuta and Oenanthe), are regarded as being among the most poisonous plants both in North America and in the United Kingdom. Despite their toxicity, the literature consists almost entirely of case reports. AIM: The aim of this review is to summarize this literature by covering all aspects of taxonomy and botanical characterization, principal toxins, basic pharmacology including mechanisms of toxicity, and the clinical features, diagnosis, and management of poisoning. MECHANISMS OF TOXICITY: The principal toxins, cicutoxin and oenanthotoxin, belong to a group of C17 conjugated polyacetylenes. They act as (noncompetitive) gamma-aminobutyric acid antagonists in the central nervous system (CNS), resulting in unabated neuronal depolarization that can lead to seizures. Ingestion of even a small amount of plant matter may result in severe intoxication. FEATURES: After ingestion, the patient is most likely to experience CNS stimulatory effects including seizures that, in the absence of aggressive supportive care, can result in death. Other features include nausea, vomiting, diarrhea, tachycardia, mydriasis, rhabdomyolysis, renal failure, coma, respiratory impairment, and cardiac dysrhythmias. MANAGEMENT: Treatment consists mainly of prompt airway management and seizure control, plus decontamination if achieved early and after stabilization. In the event of renal failure, the use of hemodialysis has been employed successfully. CONCLUSIONS: The ingestion of water hemlock can lead to serious complications that may be fatal. Prognosis is good, however, if prompt supportive care is provided.


Assuntos
Cicuta/intoxicação , Oenanthe/intoxicação , Intoxicação por Plantas/fisiopatologia , Animais , Cicuta/química , Di-Inos/isolamento & purificação , Di-Inos/intoxicação , Enedi-Inos/isolamento & purificação , Enedi-Inos/intoxicação , Álcoois Graxos/isolamento & purificação , Álcoois Graxos/intoxicação , Antagonistas GABAérgicos/isolamento & purificação , Antagonistas GABAérgicos/intoxicação , Humanos , América do Norte/epidemiologia , Oenanthe/química , Intoxicação por Plantas/etiologia , Intoxicação por Plantas/terapia , Reino Unido/epidemiologia
16.
Clin Toxicol (Phila) ; 47(4): 279-85, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19514874

RESUMO

INTRODUCTION: Aconitine and related alkaloids found in the Aconitum species are highly toxic cardiotoxins and neurotoxins. The wild plant (especially the roots and root tubers) is extremely toxic. Severe aconite poisoning can occur after accidental ingestion of the wild plant or consumption of an herbal decoction made from aconite roots. In traditional Chinese medicine, aconite roots are used only after processing to reduce the toxic alkaloid content. Soaking and boiling during processing or decoction preparation will hydrolyze aconite alkaloids into less toxic and non-toxic derivatives. However, the use of a larger than recommended dose and inadequate processing increases the risk of poisoning. METHODS: A Medline search (1963-February 2009) was conducted. Key articles with information on the use of aconite roots in traditional medicine, active (toxic) ingredients, mechanisms of toxicity, toxicokinetics of Aconitum alkaloids, and clinical features and management of aconite poisoning were reviewed. MECHANISMS OF TOXICITY: The cardiotoxicity and neurotoxicity of aconitine and related alkaloids are due to their actions on the voltage-sensitive sodium channels of the cell membranes of excitable tissues, including the myocardium, nerves, and muscles. Aconitine and mesaconitine bind with high affinity to the open state of the voltage-sensitive sodium channels at site 2, thereby causing a persistent activation of the sodium channels, which become refractory to excitation. The electrophysiological mechanism of arrhythmia induction is triggered activity due to delayed after-depolarization and early after-depolarization. The arrhythmogenic properties of aconitine are in part due to its cholinolytic (anticholinergic) effects mediated by the vagus nerve. Aconitine has a positive inotropic effect by prolonging sodium influx during the action potential. It has hypotensive and bradycardic actions due to activation of the ventromedial nucleus of the hypothalamus. Through its action on voltage-sensitive sodium channels in the axons, aconitine blocks neuromuscular transmission by decreasing the evoked quantal release of acetylcholine. Aconitine, mesaconitine, and hypaconitine can induce strong contractions of the ileum through acetylcholine release from the postganglionic cholinergic nerves. CLINICAL FEATURES: Patients present predominantly with a combination of neurological, cardiovascular, and gastrointestinal features. The neurological features can be sensory (paresthesia and numbness of face, perioral area, and the four limbs), motor (muscle weakness in the four limbs), or both. The cardiovascular features include hypotension, chest pain, palpitations, bradycardia, sinus tachycardia, ventricular ectopics, ventricular tachycardia, and ventricular fibrillation. The gastrointestinal features include nausea, vomiting, abdominal pain, and diarrhea. The main causes of death are refractory ventricular arrhythmias and asystole and the overall in-hospital mortality is 5.5%. MANAGEMENT: Management of aconite poisoning is supportive, including immediate attention to the vital functions and close monitoring of blood pressure and cardiac rhythm. Inotropic therapy is required if hypotension persists and atropine should be used to treat bradycardia. Aconite-induced ventricular arrhythmias are often refractory to direct current cardioversion and antiarrhythmic drugs. Available clinical evidence suggests that amiodarone and flecainide are reasonable first-line treatment. In refractory cases of ventricular arrhythmias and cardiogenic shock, it is most important to maintain systemic blood flow, blood pressure, and tissue oxygenation by the early use of cardiopulmonary bypass. The role of charcoal hemoperfusion to remove circulating aconitine alkaloids is not established. CONCLUSIONS: Aconite roots contain aconitine, mesaconitine, hypaconitine, and other Aconitum alkaloids, which are known cardiotoxins and neurotoxins. Patients present predominantly with neurological, cardiovascular, and gastrointestinal features. Management is supportive; the early use of cardiopulmonary bypass is recommended if ventricular arrhythmias and cardiogenic shock are refractory to first-line treatment.


Assuntos
Aconitina/intoxicação , Aconitum/intoxicação , Alcaloides/intoxicação , Aconitina/administração & dosagem , Aconitina/isolamento & purificação , Aconitum/química , Alcaloides/administração & dosagem , Alcaloides/isolamento & purificação , Animais , Relação Dose-Resposta a Droga , Humanos , Medicina Tradicional Chinesa/efeitos adversos , Intoxicação por Plantas/etiologia , Intoxicação por Plantas/fisiopatologia , Intoxicação por Plantas/terapia , Raízes de Plantas
17.
Clin Toxicol (Phila) ; 47(3): 206-12, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19306191

RESUMO

BACKGROUND: Poisoning due to deliberate self-harm with the seeds of yellow oleander (Thevetia peruviana) results in significant morbidity and mortality each year in South Asia. Yellow oleander seeds contain highly toxic cardiac glycosides including thevetins A and B and neriifolin. A wide variety of bradyarrhythmias and tachyarrhythmias occur following ingestion. Important epidemiological and clinical differences exist between poisoning due to yellow oleander and digoxin; yellow oleander poisoning is commonly seen in younger patients without preexisting illness or comorbidity. Assessment and initial management. Initial assessment and management is similar to other poisonings. No definite criteria are available for risk stratification. Continuous ECG monitoring for at least 24 h is necessary to detect arrhythmias; longer monitoring is appropriate in patients with severe poisoning. Supportive care. Correction of dehydration with normal saline is necessary, and antiemetics are used to control severe vomiting. Electrolytes. Hypokalemia worsens toxicity due to digitalis glycosides, and hyperkalemia is life-threatening. Both must be corrected. Hyperkalemia is due to extracellular shift of potassium rather than an increase in total body potassium and is best treated with insulin-dextrose infusion. Intravenous calcium increases the risk of cardiac arrhythmias and is not recommended in treating hyperkalemia. Oral or rectal administration of sodium polystyrene sulfonate resin may result in hypokalemia when used together with digoxin-specific antibody fragments. Unlike digoxin toxicity, serum magnesium concentrations are less likely to be affected in yellow oleander poisoning. The effect of magnesium concentrations on toxicity and outcome is not known. Hypomagnesaemia should be corrected as it can worsen cardiac glycoside toxicity. Gastric decontamination. The place of emesis induction and gastric lavage has not been investigated, although they are used in practice. Gastric decontamination by the use of single dose and multiple doses of activated charcoal has been evaluated in two randomized controlled trials, with contradictory results. Methodological differences (severity of poisoning in recruited patients, duration of treatment, compliance) between the two trials, together with differences in mortality rates in control groups, have led to much controversy. No firm recommendation for or against the use of multiple doses of activated charcoal can be made at present, and further studies are needed. Single-dose activated charcoal is probably beneficial. Activated charcoal is clearly safe. Arrhythmia management. Bradyarrhythmias are commonly managed with atropine, isoprenaline, and temporary cardiac pacing in severe cases, although without trial evidence of survival benefit, or adequate evaluation of possible risks. Accelerating the heart rate with atropine or beta-adrenergic agents theoretically increases the risk of tachyarrhythmias, and it has been claimed that atropine increases tachyarrhythmic deaths. Further studies are required. Tachyarrhythmias have a poor prognosis and are more difficult to treat. Lidocaine is the preferred antiarrhythmic; the role of intravenous magnesium is uncertain. Digoxin-specific antibody fragments. Digoxin-specific antibody fragments are effective in reverting life-threatening cardiac arrhythmias; prospective observational studies show a beneficial effect on mortality. High cost and lack of availability limit the widespread use of digoxin-specific antibody fragments in developing countries. CONCLUSIONS: Digoxin-specific antibody fragments remain the only proven therapy for yellow oleander poisoning. Further studies are needed to determine the place of activated charcoal, the benefits or risks of atropine and isoprenaline, the place and choice of antiarrhythmics, and the effect of intravenous magnesium in yellow oleander poisoning.


Assuntos
Nerium/intoxicação , Intoxicação por Plantas/terapia , Anticorpos Bloqueadores/uso terapêutico , Antídotos/uso terapêutico , Antieméticos/uso terapêutico , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/tratamento farmacológico , Pressão Sanguínea/efeitos dos fármacos , Carvão Vegetal/uso terapêutico , Digoxina/imunologia , Eletrocardiografia , Eméticos/uso terapêutico , Hidratação , Humanos , Ondansetron/uso terapêutico , Intoxicação por Plantas/fisiopatologia , Potássio/sangue , Ressuscitação , Irrigação Terapêutica , Desequilíbrio Hidroeletrolítico/induzido quimicamente , Desequilíbrio Hidroeletrolítico/terapia
18.
Toxicol Rev ; 25(2): 73-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16958554

RESUMO

Several species of the Veratrum genus are associated with toxicity in humans and animals. The principal toxins are steroid alkaloids; some have a modified steroid template, whereas others differ in their esterified acid moieties. These alkaloids act by increasing the permeability of the sodium channels of nerve cells, causing them to fire continuously. Increased stimulation, associated with the vagal nerve results in a reflex that causes the triad of responses known as the Bezold-Jarisch reflex: hypotension, bradycardia and apnoea. Clinically, various Veratrum extracts were marketed for clinical use as antihypertensive drugs, but because of their narrow therapeutic index were withdrawn from the market. Following the ingestion of Veratrum alkaloids, expected signs and symptoms include vomiting and abdominal pain, followed by cardiovascular effects such as bradycardia, hypotension and cardiac conduction abnormalities and death. Similar symptoms arise in other mammalian species ingesting these alkaloids; teratogenic effects may occur to the fetuses of animals that have grazed on Veratrum californicum. Treatment consists of supportive care, with an emphasis on haemodynamic stability with fluid replacement, atropine and vasopressors. The onset of symptoms occurs between 30 minutes and 4 hours, and the duration of the illness can range from 1 to 10 days; however, with prompt supportive care, patients typically make a full recovery within 24 hours.


Assuntos
Intoxicação por Plantas , Plantas Medicinais , Plantas Tóxicas , Alcaloides de Veratrum/intoxicação , Veratrum , Adulto , Animais , Humanos , Intoxicação por Plantas/diagnóstico , Intoxicação por Plantas/tratamento farmacológico , Intoxicação por Plantas/fisiopatologia , Veratrum/química , Veratrum/classificação
19.
Toxicon ; 47(4): 371-9, 2006 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-16488457

RESUMO

A disease of the nervous system was observed in goats from two farms of the semiarid of the state of Paraíba, northeastern Brazil. Ipomoea sericophylla was found in one farm and I. riedelii in the other. Both plants were administered experimentally to five goats each. Both plants induced clinical signs similar to those observed in spontaneous cases. Two goats died spontaneously and five were euthanatized. Three goats recovered after the withdrawal of the plants. Histological examination showed that all goats that died spontaneously or were euthanized had diffuse vacuolation of neurons, macrophages of lymphatic tissues, and epithelial cells of pancreas, thyroid, renal tubules and liver. On electron microscopy of Purkinje cells, numerous dilated membrane bordered vacuoles were identified as lysosomes. On lectin-histochemical analysis, cerebellar cells gave positive reactions to Concanavalia ensiformis, Triticum vulgaris, and succinylated-T. vulgaris, which indicate the storage of alpha-D-mannose, alpha-D-glucose, beta-D-N-acetyl-glucosamine, and acetyl-neuraminic acid. The chemical analysis of I. sericophylla and I. riedelii showed 0.11 and 0.14% of swainsonine, respectively. The latter also contained calystegines B1, B2 and C1. It is concluded that I. sericophylla and I. riedelli cause a lysosomal storage disease.


Assuntos
Ipomoea/toxicidade , Doenças do Sistema Nervoso/etiologia , Intoxicação por Plantas/fisiopatologia , Alcaloides/análise , Animais , Brasil , Cabras , Doenças do Sistema Nervoso/patologia , Doenças do Sistema Nervoso/fisiopatologia , Extratos Vegetais/análise , Intoxicação por Plantas/patologia , Swainsonina/análise , Tropanos
20.
Onderstepoort J Vet Res ; 72(1): 39-53, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15991704

RESUMO

Ingestion of the plant Nolletia gariepina was confirmed as the cause of acute mortalities in cattle in the Kuruman area of the Northern Cape Province of South Africa. The aim of this trial was to investigate the toxic effects of this plant with respect to clinical signs, pathophysiology and pathology using the sheep as a model. At dosages of 1.5 g dried, milled plant material/kg body mass there were no detectable abnormal findings, while at dosages of 2.8-3.0 g/kg most of the animals died acutely. In subacutely affected sheep, depression, inappetance, teeth grinding, tachycardia, weak ruminal movements and recumbency were noticed. The most prominent pathophysiological changes observed, included a sharp rise in non-protein nitrogen substances in the plasma, remarkable decline in glomerular filtration rate, increase in sodium and potassium excretion, and a rise in urine gamma glutamyltransferase activity. Macroscopically a severe nephrosis was present in all the animals. The most important findings detected histologically were necrosis of the proximal convoluted tubular epithelium and large numbers of protein casts in the lumens.


Assuntos
Asteraceae/intoxicação , Rim/patologia , Intoxicação por Plantas/veterinária , Doenças dos Ovinos/etiologia , Doença Aguda , Animais , Aspartato Aminotransferases/sangue , Relação Dose-Resposta a Droga , Taxa de Filtração Glomerular/efeitos dos fármacos , Taxa de Filtração Glomerular/veterinária , Rim/efeitos dos fármacos , Rim/fisiopatologia , Testes de Função Renal/veterinária , Fígado/patologia , Masculino , Necrose , Nitrogênio/sangue , Concentração Osmolar , Extratos Vegetais/intoxicação , Intoxicação por Plantas/patologia , Intoxicação por Plantas/fisiopatologia , Potássio/urina , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/patologia , Doenças dos Ovinos/fisiopatologia , Sódio/urina , Toxinas Biológicas/intoxicação , Urina/química , gama-Glutamiltransferase/sangue , gama-Glutamiltransferase/urina
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