Poisonous Species Research Articles

Hygrocybe rimosa (Hygrophoraceae, Agaricales), a new poisonous species from southern China

Hygrocybe rimosa, a new poisonous species belonging to subg. Hygrocybe, is described from southern China with both phylogenetic and morphological data. This species can cause nausea, vomiting, and abdominal pain. Morphologically, it is characterized by its orange to red and fibrillose pileus, irregularly split pileus margin, free, broad to ventricose, white lamellae, and subglobose to oblong basidiospores measuring (7)7.5–11 ×5–8(8.5) μm. Phylogenetically, analyses based on the internal transcribed spacer (ITS) region and the nuclear ribosomal RNA large subunit (LSU) indicate that H. rimosa is a member of subg. Hygrocybe. Ecologically, the new taxon usually grows in subtropical grasslands.

Facile provision of CuO-Kaolin nanocomposite for boosted sonocatalytic removal of Cr(VI) from hydrous media

ABSTRACT Nowadays, nanoscale materials have been widely applied in the removal of contaminants from the water system. Reduction of Cr(VI) (as a poisonous species) to Cr(III) (as a slight toxic species) was performed using CuO-Kaolin with ultrasound (US) irradiation. The CuO-Kaolin nanocomposite was synthesized via a facile co-precipitation method. Then X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope and Energy dispersive X-ray spectroscopy analyses were performed to identify the structural features of CuO-Kaolin. The role of influential parameters for the reduction of Cr(VI) was investigated in sonocatalytic advanced oxidation system. About 89.35% of Cr(VI) was removed via US/CuO-Kaolin process after 90 min at optimum conditions (pH = 3, sonocatalyst dosage = 1 g L−1 and [Cr (VI)]0 = 20 mg L−1). This outstanding result was due to the synergistic effect of the increased electron delivery to conduction band on CuO-Kaolin nanocomposite and the increased reactive surface region of nanoparticles by sonication. The presence of H2O2 as an amplifier improved the removal efficiency of Cr(VI) from 89.35% to 100% after 20 min. Kinetic experimental results were well described by a pseudo-first-order kinetic model. Desorption experiments showed excellent stability of sonocatalyst during the reaction and maintenance of the catalytic activity up to 10 sequential cycles.

Evidence that toxin resistance in poison birds and frogs is not rooted in sodium channel mutations and may rely on "toxin sponge" proteins.

Many poisonous organisms carry small-molecule toxins that alter voltage-gated sodium channel (NaV) function. Among these, batrachotoxin (BTX) from Pitohui poison birds and Phyllobates poison frogs stands out because of its lethality and unusual effects on NaV function. How these toxin-bearing organisms avoid autointoxication remains poorly understood. In poison frogs, a NaV DIVS6 pore-forming helix N-to-T mutation has been proposed as the BTX resistance mechanism. Here, we show that this variant is absent from Pitohui and poison frog NaVs, incurs a strong cost compromising channel function, and fails to produce BTX-resistant channels in poison frog NaVs. We also show that captivity-raised poison frogs are resistant to two NaV-directed toxins, BTX and saxitoxin (STX), even though they bear NaVs sensitive to both. Moreover, we demonstrate that the amphibian STX "toxin sponge" protein saxiphilin is able to protect and rescue NaVs from block by STX. Taken together, our data contradict the hypothesis that BTX autoresistance is rooted in the DIVS6 N→T mutation, challenge the idea that ion channel mutations are a primary driver of toxin resistance, and suggest the possibility that toxin sequestration mechanisms may be key for protecting poisonous species from the action of small-molecule toxins.

Unpalatable plants induce a species-specific associational effect on neighboring communities

In grazing conditions, unpalatable species may induce either associational defense or neighbor contrast susceptibility in neighboring communities. Using surveys from eight grasslands, we tested whether various unpalatable species have the same impacts on neighboring communities in response to grazing. The studied unpalatable species were: Phlomis cancellata (an unpalatable nonpoisonous plant), Euphorbia boissieriana, E.microsciadia (poisonous plants), and Seseli transcaucasicum (a highly poisonous plant). Our results showed that, in the ungrazed grasslands, communities containing P. cancellata had lower biodiversity than communities without it. In the moderately- and heavily grazed grasslands, P. cancellata induced associational defense in the neighboring communities. In heavily grazed grasslands, both Euphorbia species promoted neighbor contrast susceptibility in the neighboring communities. Similarly, S. transcaucasicum in a heavily grazed grassland, induced neighbor contrast susceptibility. Different responses of plant community vulnerability among the studied unpalatable plants might be due to herbivore different foraging decisions. Accordingly, grazers selectively choose from other patches when facing P. cancellata and other plant individuals when there is a poisonous plant in a patch. Our results suggested that grazing intensity may not substantially affect the foraging decisions of sheep and goats in response to unpalatable species. We recommend monitoring the abundance of poisonous species to maintain the sustainable use of grasslands.

A REVIEW ON SOME CULTIVATED AND NATIVE POISONOUS PLANTS IN ADEN GOVERNORATE, YEMEN

Plant poisoning is a health concern in many countries where plants are used either accidently, especially among children, or intentionally for purposes such as assassination, suicide, hunting, fishing and treating various diseases. Presently, despite the implementation of toxicology surveillance systems in many countries, plant poisoning continues to be a preventable cause of morbidity and mortality.
 In the Aden governorate of Yemen, there are no laws or regulations for the prevention of plant poisoning, despite the existence of several poisonous species in gardens, and as roadside trees planted by the local authority, or growing wildly in public areas. In addition, there is a lack of scientific studies on the risks of these poisonous plants. Therefore, we undertook this study, based on scientific review, to document and illustrate the botanical, geographical and toxicological characteristics of fourteen poisonous plants collected from different districts of Aden governorate.
 The documented poisonous species (6 species) belong to Apocynaceae followed by Fabaceae (2 species), whereas Aristolochiaceae, Cucurbitaceae, Dracaenaceae, Euphorbiaceae, Meliaceae, and Verbenaceae are represented by one species each. The toxic parts of the majority of studied poisonous species are the whole plant, latex, seeds, and fruits. Cardiotoxicity, cytotoxicity, gastrointestinal toxicity, and inflammation of skin and mucous membrane are the main clinical manifestations. They are caused by varying amounts of plant toxins such as cardiac glycosides in Calotropis procera, Cryptostegia grandiflora, Nerium oleander and Thevetia peruviana, and cytotoxic toxins such as toxalbumins in Abrus precatorius and Ricinus communis, aristolochic acids in Aristolochia bracteolate, and vinca alkaloids in Catharanthus roseus, as well as gastrointestinal toxins such as cucurbitacins in Citrullus colocynthis, and tannins in Caesalpinia pulcherrima. Inflammation of skin and mucous membrane is caused by calcium oxalate crystals in Calotropis procera latex, and soluble protein in Cryptostegia grandiflora latex. Moreover, Azadirachta indica caused a number of toxicities attributed partially to tetranortriterpenoids, while Sansevieria trifasciata toxicity was reported to be low.
 The significance of this work is to promote the awareness among the local authority to take legal actions against plant poisoning. In addition, it provides the physicians with scientific information for the diagnosis and treatment of poisoning by some plants. It is hoped that this study motivates researchers to conduct further research on poisonous plants throughout Yemen.

Electrochemical Performance Improvement of the Catalyst of the Methanol Microfuel Cell Using Carbon Nanotubes

In this research, the electrocatalytic activity of platinum-ruthenium nanoparticles on carbon nanotubes and carbon black in methanol oxidation reaction has been investigated. Moreover, the electrochemical performance of a single passive direct methanol fuel cell run by these two different electrocatalysts has been reported. Physical characterization and electrochemical tests reveal the superiority of PtRu on carbon nanotubes. Based on the voltammetry outcomes, it was found that methanol oxidation reaction kinetics has been improved on the nanotube-supported catalyst. The current density of oxidation reaction has increased up to 62% in nanotube sample compared to carbon black-supported one. The electrochemical test results have shown that the carbon nanotubes increase the performance of the microfuel cell by 37% at maximum power density, compared to the carbon black. Moreover, the resistance of the samples supported by carbon nanotubes to poisonous intermediate species has been found 3% more than carbon black-supported one. According to the chronoamperometry test results, it was concluded that the performance and sustainability of the carbon nanotube electrocatalyst show a remarkable improvement compared to carbon black electrocatalyst in the long term.

Chromosome-level genome assembly of the humpback puffer, Tetraodon palembangensis.

The humpback puffer, Tetraodon palembangensis, is a poisonous freshwater pufferfish species mainly distributed in Southeast Asia (Thailand, Laos, Malaysia and Indonesia). The humpback puffer has many interesting biological features, such as inactivity, tetrodotoxin production and body expansion. Here, we report the first chromosome-level genome assembly of the humpback puffer. The genome size is 362Mb, with a contig N50 value of ∼1.78Mb and a scaffold N50 value of ∼15.8Mb. Based on this genome assembly, ∼61.5Mb (18.11%) repeat sequences were identified, 19,925 genes were annotated, and the function of 90.01% of these genes could be predicted. Finally, a phylogenetic tree of ten teleost fish species was constructed. This analysis suggests that the humpback puffer and T. nigroviridis share a common ancestor 18.1 million years ago (MYA), and diverged from T. rubripes 45.8 MYA. The humpback puffer genome will be a valuable genomic resource to illustrate possible mechanisms of tetrodotoxin synthesis and tolerance.

Status of poisonous plants and their toxic importance for general people awareness in South-eastern Rajasthan

Present study conducted on poisonous or toxic plants abundance in south-eastern Rajasthan which are not identified by the local people, particularly preschool children are prone to be victimized by eating poisonous plants accidentally. Sometimes due to confusion or ignorance human beings use poisonous plants for daily needs like wild edible plants, infectivity of food with noxious plants, or by the use of plants use as remedies for some ailments. All these plants can affect either whole body spectrum or slightest quantity. The poisonous plants recorded from the study area are arranged alphabetically, each by its botanical name, followed by family and local names with their toxic principles and toxicity. Total 45 poisonous plant species were recorded belonging to 30 different families from the study area. Maximum poisonous plants species were recorded from Euphorbiaceae family and followed by Poaceae family. The traditional uses are described with details of toxic plant parts used, toxic principles and notes on toxic effects on humans and livestock. This paper provides valuable information for local people to be aware of poisonous or harmful plants available to their surroundings.

The Spectrum of Weed Species and Fungal Pathogens in Stands of Alternative Fodder Crop Lolium Multiflorum Var. Westerwoldicum Growing up in a Drought-Prone Area in the Czech Republic

Annual ryegrass (Lolium multiflorum var. westerwoldicum) is cultivated in various areas of the world as a feed for live stock. Efforts to improve the production of high-quality feed in the face of deepening climate change have increased the demand for growing non-traditional types of crops, including ryegrass. The aims of the research were to determine the spectrum of weed and fungal pathogen species and to assess dangerous species of weeds and pathogens which negatively affect forage crops of annual ryegrass grown in dry conditions. In 2018-2019 the occurrence of weeds and fungal pathogens of ryegrass was evaluated in field conditions. The assessed lands were located in dry climatic conditions of South Moravia (Czech Republic). The vegetation recording was done on phytosociological plots of 12 m2. A total of 57 weed species were identified in the plots, where 12 species were toxic and 16 species were undesirable. The most problematic weeds and poisonous species were: Aethusa cynapium, Datura stramonium, Equisetum palustre, Euphorbia helioscopia, Fumaria officinalis and Solanum nigrum, which can cause health problems if present in cattle feed. A pathogenic infection caused by Blumeria graminis, Puccinia graminis var. graminicola and P. coronata var. coronata, Gaeumannomyces graminis and Drechslera sp. was identified on the ryegrass plants in the experimental plots during the vegetation. Blumeria graminis was the most abundant, but it did not endanger the final feed. The data was processed by CCA analysis.

Forensic application of DNA barcoding in the identification of commonly occurring poisonous plants

Exposure to poisonous plants is hazardous to health; thus, reliable species identification is required to decide the most appropriate treatment. Since ingested plants are too much degraded for visual observation, DNA barcoding can be used as a molecular tool for species identification. Considering the universal primers, PCR and sequencing success rate, and diversity of the poisonous plants, the rbcL DNA marker was selected for molecular identification. A reference DNA barcode library for 100 poisonous plant species was created using rbcL DNA barcodes. For the poisonous plants represented in the library, 100% and 89% species differentiation was observed at the genus and species level, respectively. All the undifferentiated species were congeneric species. Mapping the metabolites of the poisonous plants to the DNA based phylogenetic tree indicated that the phylogenetically related species also had related toxic compounds. Therefore, genus-level identification may be sufficient in the practical application of DNA barcoding in poisoning cases. We conclude that rbcL can be used as a primary marker, and if required, ITS2 or trnH-psbA may be used as a secondary marker to identify the poisonous plants. The present study provides the foundation to develop a reliable molecular method to identify the poisonous species from the vomit samples of poisoning cases.

CO as a Probe Molecule to Study Surface Adsorbates during Electrochemical Oxidation of Propene

AbstractA major challenge in the electrochemical oxidation of hydrocarbons is understanding the formation of intermediate species, some of which continue to react, while others are non‐reactive or poisonous species that block adsorption of further reactants. Herein we investigate the identity and behavior of adsorbates formed during partial oxidation of propene. We employ two techniques: Electrochemistry‐Mass Spectrometry (EC‐MS) and Attenuated Total Reflection Infrared Spectroscopy (ATR‐FTIR). In both cases, we use CO as a probe molecule, to perturb the ad‐layer of propene intermediates. In the EC‐MS experiments, propene and its intermediates were quantified by triggering their desorption via displacement with CO. We show evidence for at least two distinct classes of propene adsorbates, via CO displacement and electrochemical stripping. A redshift in the ν(C−O) mode was observed, during IR spectroscopy, reflecting the chemical environment arising from strongly bound propene intermediates.

Diversity of Segetal Flora in Salix viminalis L. Crops Established on Former Arable and Fallow Lands in Central Poland

The flora of willow (Salix viminalis L.) plantations consists of various plant groups, including plants related to arable land, called segetal plants. Knowledge of this flora is important for maintaining biodiversity in agroecosystems. The aim of the study was to assess the segetal flora of the willow plantations in central Poland, depending on the land use before the establishment of the plantations (arable land or fallow) and the age of the plantations. Moreover, the aim was also to check for the presence of invasive, medicinal, poisonous and melliferous species. The vegetation accompanying willow was identified based on an analysis of 60 phytosociological relevés performed using the Braun-Blanquet method. For each species, the following parameters were determined: the phytosociological class; family; geographical and historical group; apophyte origin; biological stability; life-form; and status as an invasive, medicinal (herbs), poisonous or melliferous species. The results were statistically processed. Segetal species accounted for 38% of the flora accompanying willow. The plantations on former arable land were richer in segetal species than those on fallow. Mostly, short-lived and native species dominated. In line with the age of the plantations, the number of segetal species decreased. The share of apophytes increased, and anthropophytes decreased. Furthermore, many valuable plants were found among the flora accompanying willow.

Alpha-mannosidosis caused by toxic plants in ruminants of Argentina.

It is well known that several of the swainsonine-containing plant species found widespread around the world have a negative economic impact in each country. In Argentina, most of the information on the poisonous plant species that produce α-mannosidosis is published in Spanish and thus not available to most English-speaking researchers interested in toxic plants. Therefore, the aim of this review is to summarize the information about swainsonine-containing plants in Argentina, which are extensively distributed throughout different ecoregions of the country. To date, five species from three genera have been shown to induce α-mannosidosis in livestock in Argentina: Ipomoea carnea subsp. fistulosa, Ipomoea hieronymi subsp. calchaquina (Convolvulaceae), Astragalus garbancillo, Astragalus pehuenches (Fabaceae), and Sida rodrigoi (Malvaceae). These species contain the indolizidine alkaloid swainsonine, which inhibits the lysosomal enzyme α-mannosidase and consequently affects glycoprotein metabolism, resulting in partially metabolized sugars. The prolonged consumption of these poisonous plants produces progressive weight loss and clinical signs related to a nervous disorder, characterized by tremors of head and neck, abnormalities of gait, difficulty in standing, ataxia and wide-based stance. Histological lesions are mainly characterized by vacuolation of different cells, especially neurons of the central nervous system. The main animal model used to study α-mannosidosis is the guinea pig because, when experimentally poisoned, it exhibits many of the characteristics of naturally intoxicated livestock.

Cross-mixing study of a poisonous Cestrum species, Cestrum diurnum in herbal raw material by chemical fingerprinting using LC-ESI-QTOF-MS/MS

Poisonous plants are widely distributed and may have risk of phytotoxicity upon mixing with medicinal plants. Several species of Cestrum genus are poisonous and linked with many serious health issues. In the present study, cross-mixing of a toxic plant, Cestrum diurnum with morphologically resembling medicinal plant, Adhatoda vasica was studied using chemical fingerprinting approach. LC-ESI-MS/MS tool was used to develop the chemical fingerprints of three toxic species of Cestrum, including, C. diurnum, C. nocturnum and C. parqui. Total forty-three compounds were identified using high-resolution LC-ESI-MS/MS data comparison. Chemometric analyses were done to compare the distribution of identified compounds present in these Cestrum species. One of the identified compounds, nornicotine (a toxic compound) was also quantified using LC-IT-MS/MS. Adulteration study was conducted by mixing toxic C. diurnum in A. vasica with various ratios (w/w) and five differentiable compounds were identified to detect the adulteration. The method was able to detect up to the limit of 5% mixing of toxic C. diurnum. Moreover, cytotoxicity of the methanolic extracts of these three species were also studied on normal human PBMC (peripheral blood mononuclear cells) and all found to be toxic, while the C. nocturnum showed the highest level of toxicity with the IC50 12.5 μg/mL.

Population structure and quantitative dynamics of Stellera chamaejasme in degraded typical steppe

Stellera chamaejasme is one of most common poisonous plant species in degraded grasslands of China. S. chamaejasme could dominate the community in some severely degraded grasslands, which is a serious threat to the sustainable development of animal husbandry in natural grasslands. In this study, S. chamaejasme population was divided into 10 age classes according to the number of branches. We investigated the age structure of S. chamaejasme population and population dynamic indices, and quantified the survival status of S. chamaejasme population by compiling a static life table, drawing a survival curve, conducting survival analysis. The age structure of S. chamaejasme population in the study area was growth type. The number of individuals in Ⅰ age class was sufficient but with relatively low survival rate. The population structure of S. chamaejasme was fitted the growing type. The development process of population was fluctuating. The number of individuals would drop sharply in Ⅱ and Ⅷ, indicating that these two age classes were the bottleneck period in the development of S. chamaejasme population. The survival curves of S. chamaejasme population was the Deevey-Ⅱ type. The results of survival analysis showed that the population had a sharp decrease in the early stage and was stable in the later stage, which was because the value of fx and λx of S. chamaejasme in Ⅰ or Ⅱ age class were the highest. In conclusion, sufficient young individuals (Ⅰ) was the basis for the expansion of S. chamaejasme population in the degraded typical steppe. The low transformation rate of young individuals to adults might be one of the reasons explaining why S. chamaejasme population could not expand rapidly in the early stage of grassland degradation. Therefore, it was suggested to intervene early when the number of S. chamaejasme was limited.

Air curtain to control smoke and fire spread in a ventilated multi-floor building

Compartment fire is a hazardous phenomenon because of the generated poisonous and high-temperature gases. Air curtain systems can be used in order to control the fire spread. This paper examines the numerical simulation method with a focus on the combustion model which can model the poisonous gases and investigates the effect of air curtain on fire. The results of the flamelet generated manifold (FGM) combustion model, which considers all of the poisonous species with detail, in compartment fire with single and multi-floor building have been verified. A three-floor compartment fire scenario with methane as a fuel of 62.9, 500, and 5000 kW heat release rate, which represents over to under-ventilation, was selected as a test case. The impact of air curtains with various supply angles, velocity, and ventilation on pollutants and temperature distribution was examined. The mass fraction of CO and CO2 species reached near zero at angles of 12 and 24, at the over-ventilated case when using air curtain. Therefore, there is no hazard for the upper floors in case of using air curtain. However, in the under-ventilated case, it is necessary to improve the efficiency of air curtain by using ventilation in the fire room and increasing the exhaust velocity of the air curtain.

Mycological rationality: Heuristics, perception and decision-making in mushroom foraging

AbstractHow do mushroom foragers make safe and efficient decisions under uncertainty, or deal with the genuine risks of misidentification and poisoning? This article is an inquiry into ecological rationality, heuristics, perception, and decision-making in mushroom foraging. By surveying 894 Finnish mushroom foragers, this article illustrates how socially learned rules of thumb and heuristics are used in mushroom foraging, and how simple heuristics are often complemented by more complex and intuitive decision-making. The results illustrate how traditional foraging cultures have evolved precautionary heuristics to deal with uncertainties and poisonous species, and how foragers develop selective attention through experience. The study invites us to consider whether other human foraging cultures might use heuristics similarly, how and why such traditions have culturally evolved, and whether early hunter-gatherers might have used simple heuristics to deal with uncertainty.

Research progress of nanomaterial-mediated photodynamic therapy in tumor treatment

Photodynamic therapy (PDT) is a new approach to destroy tumor over past decades due to its high selectivity and minimal invasiveness. Photosensitizers (PSs), plenty of oxygen, and special wavelengths of light irradiation are three indispensable basic elements in the PDT therapeutic procedure. Upon exposed to light irradiation, PSs utilized surround oxygen to produce poisonous reactive oxygen species (ROS) to kill cancer cells through apoptosis or necrosis. PDT cased cancer cells damage highly dependent on tissue oxygen concentration and DNA self-repairing inhibition. Therefore, altering ROS homeostasis in cancer cells can be exploited for tumor therapeutic. Furthermore, PDT as the highly selective therapy approach can directly ablate solid tumor at primary sites. Meanwhile, it can induce immunogenic cell death by release damage-associate molecular patterns and tumor-associated antigens to activate immune response for inhibit cancer recurrence and metastasis. However, PDT was seriously hampered due to the poor drug penetration depth and unfavorable biodistribution of PSs at the lesion tissues. As the development of nanomaterial, nanotechology-based PDT have made a huge revolution in cancer therapeutic, which can effectively overcome these drawbacks and ameliorate the complex tumor microenvironment to enhance PDT effects. In general, the size of nanoparticles between 50 and 100 nm can prolong blood circulation time and efficiently tumor accumulation through enhanced permeability and retention (EPR) effects. Once inside the tumor tissues, they should be small enough to enhance penetration. Given this, we summarize the advances of PDT in tumor therapeutic.

Wild mushrooms poisoning: a public health challenge

Abstract Issue Mushrooms are considered as ingredient of gourmet cuisine across the globe and mushroom poisonings can occur because of misidentification of a poisonous species as edible. Of the vast number of mushroom species, approximately 100 are toxic(**). Description of the Problem Mushroom poisoning is a public health problem. People should be educated about this poison as often there are no guidelines about the treatment of mushroom toxicity. Despite treatment, the prognosis can be mortal. In the Department of Hygiene and Health Prevention (ATS Val Padana, Italy) expert mycologists offer their consultation free of charge to people who pick mushrooms and register, for each consultation, quantity and toxicity of collected mushrooms. Results In 2018-19, 279 consultations were offered: 124(44.44%) in 2018, 155 (55.56%) in 2019. 58.42% of mushrooms were considered not dangerous for human health, without any difference among the two considered years (p = 0.167). 233.7 kg mushrooms were considered edible (mean 2.71, SD 16.44), 92.95 kg were considered dangerous and destroyed (mean 1.39, SD 6.99). The most identified species were: Agrocybe aegerita (11.47%), Armillaria Mellea (29.75%), Boletus edulis (6.45%), Macrolepiota venenata** (1.43%, N = 4), Xerocomus badius (2.51%), Lyophillum loricatum (1.79%), Agaricus Xanthodermus** (3.23%, N = 9). Intoxications occurred among people who did not refer to our mycology unit. Conclusions Mushroom poisoning represents a major health risk and as it's often consequence of misidentification, a free of charge consultation offered by experts is fundamental to avoid intoxications or deaths. Key messages Mushroom poisoning presents a major health risk. A free of charge consultation offered by experts is fundamental to avoid intoxications or deaths.

Effects of Senecio selloi (Spreng.) DC flower extract on mitochondrial membrane peroxidation and enzyme activities

Ethnobotanical use of plants may include poisonous species. Senecio (Asteraceae) is used as medicinal around the world. Senecio selloi (Spreng.) is widespread in Argentina. Purposes of this study were to investigate phytochemistry and in vitro activity of a methanolic extract of plant flowers on mitochondrial membrane peroxidation and enzyme activities. Chemiluminescence was used to test peroxidative effects, and thiazolyl blue tetrazolium bromide test (MTT) for cell viability. Results indicate presence of flavonoids and pyrrolizidine alkaloids. Regarding chemiluminescence, extract showed protective effect against peroxidation, while MTT demonstrated lower activities of mitochondrial dehydrogenases and cytosolic reductases, effects that were attributed to flavonoids and pyrrolizidine alkaloids, respectively. When ingested, pyrrolizidine alkaloids undergo hepatic biotransformation that cause damage to cells. On the contrary, toxicity does not take place when there is no metabolization. These situations may explain the ethnobotanical use of some poisonous senecios in human and veterinary medicine.