Investigation of cardiac glycosides from oleander in a human induced pluripotent stem cells derived cardiomyocyte model.

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.

Behavioural, electrocorticographic, and electromyographic alterations induced by Nerium oleander ethanolic extract: Anticonvulsant therapeutics assessment.

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.

Physiological response, function of sweat glands, and hair follicle cycling in cattle in response to fescue toxicosis and hair genotype.

Fescue toxicosis is a syndrome that results when cattle consume toxic endophyte-infected tall fescue. The objective of this study was to compare the response in physiological variables, sweat gland function, hair follicle cycling, and gene expression to feeding a total mixed ration that included tall fescue haylage and tall fescue seed containing a toxic endophyte (EI) or tall fescue haylage containing a nontoxic novel endophyte (EN) in beef heifers (Angus × Senepol heifers, n = 31) with 2 different hair genotypes. Numbers in each subgroup were as follows: novel endophyte, heterozygous slick (EN-S; n = 8), novel endophyte, homozygous hairy (wild type, EN-W; n = 7), endophyte-infected, heterozygous slick (EI-S; n = 10), and endophyte-infected, homozygous hairy (wild type, EI-W; n = 6). Physiological measurements were taken weekly for 7 wk. Data were analyzed using the MIXED procedure of SAS including dietary fescue treatment (EN vs. EI) and hair genotype (S vs. W) as main effects, day as a repeated measure, and temperature-humidity index (THI) as a covariate. Skin biopsies were taken before treatment initiation and on day 37 of treatment. Average surface temperature (ST) increased as the THI increased (P < 0.0001). Average ST was greater (P < 0.01) for animals fed EI than for animals fed the EN fescue diet, and greater (P < 0.01) for animals with the W genotype compared with animals with the S genotype. The difference between heifers with the S and W genotype was greater at greater THI (genotype × day interaction, P < 0.01). Transepidermal water loss (TEWL) was greater (P < 0.05) for animals with the S genotype compared with the W genotype and greater (P < 0.05) for heifers with the S genotype than for heifers with the W genotype when fed EI (36.7, 38.5, 30.0, and 38.7 g/m2 per hour for EN-W, EN-S, EI-W, and EI-S, respectively). The fraction of follicles in telogen in plucked hair samples for heifers fed EI was greater for animals with the S genotype than the W genotype (fraction in telogen: 0.456, 0.565, 0.297, 0.702 for EN-W, EN-S, EI-W, and EI-S, respectively; diet × genotype interaction, P < 0.05). Fraction of follicles in anagen was the opposite. EI fescue resulted in increased ST, changes in hair follicle cycling that support greater hair growth, and decreased TEWL for heifers with the W genotype compared with S genotype, suggesting greater heat stress in response to EI.

Yew poisoning - pathophysiology, clinical picture, management and perspective of fat emulsion utilization.

The article presents pathophysiology, clinical picture and management of yew poisoning. Authors present also their own experiences with treating yew poisoning with fat emulsion. Plants of the yew genus, of which in Europe predominates Taxus baccata, are well known for their toxic properties. Particularly high concentrations of poisonous alkaloids are present in the needles of this evergreen and highly popular decorative plant. The danger associated with accidental or intentional ingestion of yew is primarily related to the cardiotoxic effects of the alkaloids (taxine A and B). Taxine B shows a much stronger toxic effect on the heart than taxine A. It affects atrio-ventricular conduction, what may result in a widening of the QRS complexes, atrio-ventricular blocks (A-V) of II/III degree and even in asystole. Yew poisoning is relative rare and evidence-based treatment guidelines on management of such poisoning is hard to prepare. The first-line treatement should base on suportive therapy. In some cases extracorporeal life support therapies such veno-arterial ECMO should be consider. There are also premise based on case reports and mechanism of action that the use of fat emulsion may be effective rescue treatment.

"Chaotic Arrhythmia" During Successful Resuscitation After Ingestion of Yew (Taxus baccata) Needles.

OBJECTIVE: The study aims to describe the management of a case of life-threatening yew (Taxus baccata) intoxication. BACKGROUND: The needles of the yew tree contain highly cardiotoxic taxines. Intoxication with taxines, typically as part of suicide attempts, may lead to potentially lethal arrhythmias which often require prolonged cardiopulmonary resuscitation and other supportive measures. No specific therapy has been described. In some cases, extracorporeal life support has been used. CASE: After an attempted suicide with yew needles and out-of-hospital cardiac arrest, a female adolescent was resuscitated for 6 hours according to Advanced Cardiovascular Life Support guidelines. Complex ventricular tachycardias were treated by repeated direct current shocks and broad complex bradycardia managed with transvenous cardiac pacing. Antiarrhythmic drugs (amiodarone, lidocaine), magnesium sulfate, and supportive measures (intravenous lipids, sodium bicarbonate) were provided. The arrhythmias finally resolved, and the patient did not show any significant neurological or cardiac short-term sequelae after 24 hours. RESULTS: The authors describe the successful management of a case of severe taxine intoxication by prolonged conventional advanced cardiac life support lasting for more than 6 hours. CONCLUSIONS: In life-threatening yew intoxication, prolonged cardiopulmonary resuscitation is absolutely essential owing to the long duration of the cardiotoxic action of taxines and can lead to an outcome without cardiac or neurological sequelae.

Cardiac arrhythmias, electrolyte abnormalities and serum cardiac glycoside concentrations in yellow oleander (Cascabela thevetia) poisoning - a prospective study.

BACKGROUND: Consumption of yellow oleander (Cascabela thevetia) is a popular method of intentional self-harm in South India. OBJECTIVES: The objectives of this study were to identify the cardiac arrhythmias and electrolyte abnormalities in yellow oleander poisoning and to identify the association between electrolyte abnormalities, cardiac glycoside concentrations at admission and the severity of cardiotoxicity. This study was also designed to identify clinical and biochemical parameters at presentation which predict serious arrhythmias and determinants of mortality. MATERIALS AND METHODS: This was a prospective study among 192 patients who attended our Emergency department after consuming yellow oleander seeds. Patients were monitored with serial ECGs. Serious cardiac arrhythmias included sinus bradycardia <40/min, sinus arrest/exit block, second or third degree AV block, atrial tachyarrhythmias and ventricular tachyarrhythmias. Serum sodium, potassium, magnesium, total calcium and cardiac glycoside concentrations were measured at presentation for all 192 patients. Serial estimation of cardiac glycoside concentration was done in 43 patients who presented within 24 hours of consuming at least five seeds. RESULTS: At presentation, 46 patients had serious arrhythmias and on follow-up, 11 developed new-onset serious arrhythmia. Sinus bradycardia (27%) was the most common arrhythmia followed by second-degree AV block (17%); multiple arrhythmias were observed in 18%. Digoxin effect in ECG correlated significantly with hyperkalemia. Mortality rate was 5%. Serum sodium, total calcium and magnesium levels did not correlate with cardiotoxicity. Cardiac glycoside concentration was of relatively modest clinical utility to discriminate patients with serious dysrhythmias (AUC: 0.719, 95% CI: 0.63-0.81). Prolonged PR interval and digoxin effect in ECG were significantly associated with an increased likelihood of serious dysrhythmias. Increase in 0.4 number of seed intake increased the odds of mortality by 1.5 times when all other independent variables were kept constant. CONCLUSION: Cardiac glycoside concentration at the time of presentation predicted the development of new-onset serious arrhythmias. Although serum potassium correlated significantly with cardiac glycoside concentration at admission and overall serious dysrhythmias, it did not predict the development of new-onset serious arrhythmia. On the whole, serious dysrhythmias were significantly associated with higher number of seeds ingested, hypotension at admission, PR interval prolongation, presence of digoxin effect in ECG, hyperkalemia and higher cardiac glycoside concentration. The independent determinants of mortality were larger number of seeds ingested and hypotension at admission. Cardiac glycoside concentration and hyperkalemia failed to be independent markers of serious dysrhythmias as well as mortality.

Hikers poisoned: Veratrum steroidal alkaloid toxicity following ingestion of foraged Veratrum parviflorum.

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.

Toxic plants affecting the nervous system of ruminants and horses in Brazil / Plantas tóxicas que afetam o sistema nervoso de ruminantes e equinos no Brasil

This review updates information about neurotoxic plants affecting ruminants and equidae in Brazil. Currently in the country, there are at least 131 toxic plants belonging to 79 genera. Thirty one of these poisonous plants affect the nervous system. Swainsonine-containing plants (Ipomoea spp., Turbina cordata and Sida carpinifolia) cause numerous outbreaks of poisoning, mainly in goats, but cattle and horses are occasionally affected. The poisoning by Ipomoea asarifolia, a tremorgenic plant, is very common in sheep, goats and cattle in the Northeastern region and in the Marajo island. Poisoning by the pods of Prosopis juliflora are frequent in cattle in Northeastern Brazil; occasionally this poisoning affects goats and more rarely sheep. Some poisonings by plants, such as Hybanthus calceolaria, Ipomoea marcellia and Talisia esculenta in ruminants and Indigofera lespedezioides in horses were recently described and needs to be accurately investigated about its occurrence and importance. Other plants poisonings causing nervous signs in ruminants and equidae are less important, but should be considered for the differential diagnosis of neurologic diseases.(AU)

Esta revisão tem por objetivo atualizar as informações sobre plantas neurotóxicas que afetam ruminantes e equinos no Brasil. Atualmente sabe-se que existe no país pelo menos 131 plantas tóxicas pertencentes a 79 gêneros. Trinta e uma espécies afetam o sistema nervoso. As plantas quem contém swainsonina (Ipomoea spp., Turbina cordata and Sida carpinifolia) causam numerosos surtos de intoxicação, principalmente em caprinos, mas bovinos e cavalos são ocasionalmente afetados. A intoxicação por Ipomoea asarifolia, uma planta tremorgênica, é muito comum em ovinos, caprinos e bovinos na região Nordeste e na ilha de Marajó. A intoxicação pelas vagens de Prosopis juliflora é frequente em bovinos no Nordeste do Brasil; ocasionalmente são afetados caprinos e mais raramente ovinos. Algumas intoxicações por plantas, como Hybanthus calceolaria, Ipomoea marcellia e Talisia esculenta em ruminantes e Indigofera lespedezioides em equinos foram recentemente descritas e precisam ser investigadas com precisão sobre sua ocorrência e importância. Outras intoxicações por plantas que causam sinais nervosos em ruminantes e equídeos são menos importantes, todavia devem ser consideradas para o diagnóstico diferencial de doenças neurológicas.(AU)

Cleistanthus collinus poisoning: experience at a medical intensive care unit in a tertiary care hospital in south India.

BACKGROUND & OBJECTIVES: Ingestion of Cleistanthus collinus causes hypokalemia and cardiac arrhythmias leading to mortality in most cases. We undertook this retrospective study to evaluate the clinical presentation and predictors of outcome in critically ill patients admitted with C. collinus poisoning. METHODS: The case records of 56 patients admitted to the medical intensive care unit (MICU) of a tertiary care teaching hospital in south India (2000-2014) with C. collinus poisoning were retrospectively analysed. RESULTS: The mean age of patients was 36.7±13.3 yr; there were 30 males. Salient clinical manifestations included hypokalemia (58%), neutrophilic leucocytosis (48.2%), acute kidney injury (AKI) (42.9%), acute respiratory failure requiring mechanical ventilation (AcRFMv) (32.1%), shock (21.4%); cardiac arrhythmias and neuromuscular weakness (19.6% each); 21 patients (37.5%) had adverse outcome. Longer time-lapsed from consumption to reaching emergency room [median (interquartile range)] (hours) [49 (22-97) vs. 28 (7-56), p =0.0380 ]; higher acute physiology and chronic health evaluation II (APACHE II) score at presentation [14 (8.25-14.75) vs. 2 (0-6) P<0.001]; and presence of the following [odds ratio (95% confidence intervals)] at initial presentation: shock [37.40 (4.29-325.98), P=0.001]; AcRFMv [26.67 (5.86-121.39), P<0.001]; elevated alanine aminotransferase [5.71 (1.30-25.03), p0 =0.021]; metabolic acidosis [5.48 (1.68-17.89), P=0.005]; acute kidney injury (AKI) [5 (1.55-16.06), P=0.007]; hyponatremia [4.67 (1.25-17.44), P=0.022]; and neutrophilic leucocytosis [3.80 (1.02-14.21), P=0.047] predicted death. A significant (P<0.001) increasing trend in mortality was observed with increasing International Program on Chemical Safety Poisoning Severity Score (IPCS-CSS) grade. INTERPRETATION & CONCLUSIONS: C. collinus is a lethal poison associated with high mortality for which there is no specific antidote. Careful search and meticulous monitoring of the predictors of death and initiating appropriate corrective measures can be life saving.

Fatal Taxus baccata ingestion with perimortem serum taxine B quantification.

INTRODUCTION: Common yew (Taxus baccata) is a common decorative evergreen shrub with potentially fatal toxicity hallmarked by seizure, arrhythmia and cardiovascular collapse if ingested. Taxine B has been identified as one of the most cardiotoxic taxine alkaloids in Taxus spp, and another alkaloid, 3,5-dimethoxyphenol (3,5-DMP), is used as a marker of ingestion. We present a fatal case of ingestion of yew with perimortem serum and gastric taxine B, and 3,5-DMP concentrations. CASE PRESENTATION: A 22-year-old woman was brought to the emergency department (ED) from a nearby botanical garden after she was found apneic and pulseless after a witnessed generalized tonic clonic seizure. The patient was found to have a wide complex rhythm with persistent cardiovascular collapse and expired despite maximal supportive care in the ED. A baggie of plant material was found on the patient, identified as Taxus baccata. Perimortem serum and gastric samples were analyzed to quantify serum and gastric taxine B and 3,5-DMP concentrations. RESULTS: Perimortem serum showed a 3,5-DMP concentration of 86.9 ng/mL, and taxine B of 80.9 ug/mL. CONCLUSION: We report a perimortem serum and gastric taxine B and 3,5-DMP concentrations in a fatal case of T. baccata toxicity.

N-acetylcysteine in Cleistanthus collinus Poisoning: A Report of Two Cases in Children.

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.

Congenital malformations and other reproductive losses in goats due to poisoning by Poincianella pyramidalis (Tul.) L.P. Queiroz (=Caesalpinia pyramidalis Tul.).

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.

Toxalbumin exposures: 12 years' experience of U.S. poison centers.

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.

The relative toxicity of Delphinium stachydeum in mice and cattle.

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.

Hypoglycemia associated with oleander toxicity in a dog.

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.