Toxic plants from the perspective of a "Quilombola" community in the Cerrado region of Brazil.

A multi-disciplinary team surveyed ranchers at the Kalunga Historical and Cultural Heritage Site, in the Cerrado region of west central Brazil, to determine impacts promoted by toxic plants on cattle. The expedition to the Kalunga region was carried out by Brazilian and American researchers. Previously selected cattle ranch properties from "Vão das Almas", "Engenho II" and "Vão do Moleque" were visited. Twenty-four interviews were carried out with cattle ranchers and a questionnaire was applied to obtain information about outbreaks of native plant poisoning and their effects on livestock, and the use of local plants in phytotherapy. We classified problematic plants into three distinct categories. First, the toxic plants most cited by residents causing cattle losses were the flowers of Caryocar brasiliense Cambess ("pequi"), the fruits of Terminalia corrugata (Ducke) Gere & Boatwr. (Buchenavia tomentosa Eichler - "mirindiba" or "pau-pilão"), Eugenia dysenterica (Mart.) DC ("cagaita"), and Palicourea marcgravii A. St. Hil ("erva-café" or "cafezinho"). Secondly, other plants considered toxic, but causing less severe losses were Emmotum nitens (Benth.) Miers ("casco d'anta"), Indigofera lespedezioides (Kunth) ("timbozinho"), Ricinus communis L. ("mamona"), Pteridium esculentum (G. Forst.) Cockayne ("samambaia"), Stryphnodendron adstringens (Mart.) Coville ("barbatimão"), and Actinocladum verticillatum (Nees) McClure ex Soderstr. ("cambaúba"). The most important finding was the identification of the C. brasiliense flower as potentially toxic to cattle, which must be subject for future research. Further, we confirmed the toxicity and importance of P. marcgravii, E. dysenterica, and Terminalia corrugata. The survey highlighted phytotherapy plants used by the community, and greatly increased awareness by local livestock producers of poisonous plants for management purposes. We conclude that ethnobotanical knowledge, especially from the traditional community, is essential to understand livestock losses to toxic plants, and should be valued not only for reducing livestock losses, but also for cultural importance to the Kalunga communities in the Cerrado.

Detection of Highly Poisonous Nerium oleander Using Quantitative Real-Time PCR with Specific Primers.

Nerium oleander is one of the most poisonous plants, and its accidental ingestion has frequently occurred in humans and livestock. It is vital to develop a rapid and accurate identification method for the timely rescue of oleander-poisoned patients and the investigation of poisoning cases. In this study, a specific and highly sensitive quantitative real-time PCR (qPCR)-based method was developed to identify oleander in mixture systems and simulated forensic specimens (SFS). First, a new pair of oleander-specific primers, JZT-BF/BR, was designed and validated. Then, a qPCR method was developed using the primers, and its detective sensitivity was examined. The results showed that JZT-BF/BR could specifically identify oleander in forage and food mixtures, and qPCR was capable of accurate authentication even at a low DNA concentration of 0.001 ng/µL. This method was further applied to the analysis of SFS containing different ratios of N. oleander. The method was confirmed to be applicable to digested samples, and the detection limit reached 0.1% (w/w) oleander in mixture systems. Thus, this study undoubtedly provides strong support for the detection of highly toxic oleander and the diagnosis of food poisoning in humans and animals.

Ecological thresholds of toxic plants for sheep production and ecosystem multifunctionality and their trade-off in an alpine meadow.

Toxic plants are a natural component of alpine meadow which co-evolved with Tibetan sheep for thousands of years. One challenge for indigenous herders is to know the ecological thresholds of toxic plants and maintain their vital functions in ways that are compatible with economic income and ecological conservation. To achieve this, field trials with Tibetan sheep grazing in alpine meadow were conducted to examine the ecological thresholds of toxic plants for sheep production and ecosystem functions and their trade-offs. Our results demonstrated that the changing point values of biomass proportion of toxic plants for dry matter intake and liveweight gain of sheep were 17% and 22%, respectively. The changing point value of biomass (richness) proportion of toxic plants for soil carbon accumulation index was 31% (59%), for soil nutrient cycling index was 38% (42%), and for ecosystem multifunctionality index was 28% (50%). The trade-off between liveweight gain of sheep and ecosystem multifunctionality first decreased and then increased along the gradient of biomass proportion of toxic plants (the value of changing point was 37%), and had a significant negative correlation with richness of toxic plants. In addition, structural equation modeling indicated that toxic plants can affect the trade-off between liveweight gain of sheep and ecosystem multifunctionality though increasing acid detergent fiber of plant and decreasing plant species richness, belowground biomass and soil total phosphorus. Consequently, opinions towards toxic plants should shift from the conventional view that they are serious threat to grassland ecosystem health to an inclusive understanding that they are beneficial to livestock and ecosystem functions under certain ecological thresholds.

Phytotoxicological study of selected poisonous plants from Azad Jammu & Kashmir.

Poisonous plants cause tremendous economic losses to the livestock industry. These economic losses are deterioration in their health, decreased productivity, deformed offspring, and reduced longevity. The current study is the first comprehensive report on poisonous plants of Azad Jammu and Kashmir which systematically documents the phytotoxicological effect and mode of action in livestock. The information was gathered from 271 informants including 167 men and 104 women through semi-structured interviews and literature search through available databases. The data collected through interviews was analyzed with quantitative tools viz. the factor informant consensus and fidelity level. A total of 38 species of flowering plants belonging to 23 families and 38 genera were reported. Family Asteraceae (5 spp) was the most dominant, followed by Solanaceae (4 spp), Fabaceae (4 spp), Euphorbiaceae (4 spp) and Convolvulaceae (3 spp). Among all the species collected, herbs were the dominant life form (22 spp, 57.89%), trailed by shrubs (11 spp, 28.95%), and trees (5 spp, 13.16%). Whole plant toxicity was reported to be the highest (15 spp, 39.47%), followed by leaf toxicity (12 spp, 31.58%), seed toxicity (4 spp, 7.89%), fruit toxicity (3 spp, 10.53%), latex toxicity (2 spp, 5.26%), flowers toxicity (1 spp, 2.63%), and berries toxicity (1 spp, 2.63%). The most toxic route of administration was found oral (39 spp, 40.63%), followed by intraperitoneal (24 spp, 25%), and intravenous (21 spp, 21.88%). The most commonly affected organ was found liver (20.41%), followed by gastrointestinal tract (20.341%), CNS (16.33%), skin (14.29%), kidneys (12.24%), lungs (4.04%), reproductive organs (2.04%), spleen (1.75%), blood (1.75%), heart (1.75%), urinary tract (1.75%), and pancreas (1.75%). The maximum Fic value was found for dermatological disorders (0.91), followed by the endocrine system (0.90), gastrointestinal (0.82), neurology (0.77), nephrology (0.67), cardiovascular (0.67), urinary (0.67), respiratory (0.60), sexual (0.60) disorders. Senecio vulgaris, and Ageratum conyzoides were the most important plants with fidelity level (0.95) and (0.87). Nerium oleander, Lantana camara, Leucaena leucocephala, and Ricinus communis were the important poisonous plant with maximum fidelity level (100%). Ricinus communis with reported lowest LD50 (<20 mg/kg) was the top-ranked poisonous plant followed by Lantana camara and Justicia adhatoda (25-50 mg/kg), Nerium Oleander (157.37 mg/kg), and Datura innoxia (400 mg/kg). We found that knowledge about poisonous plants is less prevailing in the rural areas of Azad Kashmir compared to the knowledge about medicinal plants and poisonous nature of reported plants is due to production of toxic substances and presence of essential oils.

Progress in Immunoassays of Toxic Alkaloids in Plant-Derived Medicines: A Review.

Plants are the cradle of the traditional medicine system, assuaging human or animal diseases, and promoting health for thousands of years. However, many plant-derived medicines contain toxic alkaloids of varying degrees of toxicity that pose a direct or indirect threat to human and animal health through accidental ingestion, misuse of plant materials, or through the food chain. Thus, rapid, easy, and sensitive methods are needed to effectively screen these toxic alkaloids to guarantee the safety of plant-derived medicines. Antibodies, due to their inherent specificity and high affinity, have been used as a variety of analytical tools and techniques. This review describes the antigen synthesis and antibody preparation of the common toxic alkaloids in plant-derived medicines and discusses the advances of antibody-based immunoassays in the screening and detection of toxic alkaloids in plants or other related matrices. Finally, the limitations and prospects of immunoassays for toxic alkaloids are discussed.

Consumption of nephrotoxic plants among chronic hemodialysis patients in the Eastern region of Morocco: A multicentric cross-sectional study.

ETHNOPHARMACOLOGICAL RELEVANCE: The consumption of nephrotoxic plants is quite frequent in Morocco and could explain the high prevalence of indeterminate nephropathy in patients with End-Stage Kidney Disease (ESKD). AIM OF THE STUDY: to determine, in a population of chronic hemodialysis (CHD) patients and before the occurrence of ESKD, the prevalence of the use of nephrotoxic plants, in particular, Aristolochia longa L. (Bereztam) and the etiological role of plants in the rapid progression of known and unknown nephropathy toward the end stage of chronic hemodialysis. MATERIALS AND METHODS: This was a multicentric cross-sectional study spread over 12 months (May 2019-May 2020), carried out in public hemodialysis centers in the eastern region of Morocco. Clinical data were collected from medical records. Herbal and sociodemographic data were collected from a detailed and precise interview with each enrolled CHD patient. RESULTS: A total of 404 CHD patients participated in the study. 71.5%, had used medicinal plants before the occurrence of ESKD and 32.9% had indeterminate nephropathy. Among the plants consumed, we identified plants whose kidney toxicity was well demonstrated, mainly Rhamnus alaternus L. (Mlilas) in 66.7%, Artemisia herba alba Asso (Chih) in 54.32%, Aristolochia longa L.(Bereztam) in 52.6%, and Rubia tinctorum L. (Fowa) in 47.4%. 27.7% of CHD patients had presented complications following the use of the plants before the occurrence of ESKD. In multivariate analysis, the use of plants to treat digestive disorders (OR 9.57; 95%CI [4.49-20.37], P < 0.001) and asthenia associated with anemia (OR 8.59; 95%CI [3.92-18.81], P < 0.001), as well as side effects observed after taking the plants (OR 4; 95%CI [1.09, 14.7], P = 0.03), were identified as significant risk factors for the occurrence of severe indeterminate nephropathy. CONCLUSIONS: This study showed the high prevalence of consumption of nephrotoxic herbs which may be the root cause of chronic renal failure in CHD patients.

Phyto-Compounds from a Rather Poisonous Plant, Strychnos nuxvomica, Show High Potency Against SARS-CoV-2 RNA-Dependent RNA Polymerase.

BACKGROUND: The establishment of strategy to inhibit the virus replication is an attractive means in combating SARS-CoV-2 infection. OBJECTIVE: We studied phyto-compounds from Strychnos nux-vomica (a poisonous plant) against SARS-CoV-2 RNA-dependent RNA polymerase by computational methods. METHODS: Molecular docking, molecular dynamics (MD) simulation and energetics calculations were employed to elucidate the role of the phyto-compounds. RESULTS: Ergotamine with a binding free energy of -14.39 kcal/mol showed a promising capability in terms of binding affinity and the interaction to conserved motifs, especially the SDD signature sequence. The calculated dissociation constants for ATP, ergotamine, isosungucine and sungucine were 12 µM, 0.072 nM, 0.011 nM and 0.152 nM, respectively. The exhibited kd by these phyto-compounds reflected tens of thousands fold potency as compared to ATP. The binding free energies of sungucine and isosungucine were much lower (-13.93 and -15.55 kcal/mol, respectively) compared to that of ATP (-6.98 kcal/mol). CONCLUSION: Sharing the same binding location as that of ATP and having high binding affinities, Ergotamine, Isosungucine, Sungucine and Strychnine N-oxide could be effective in controlling the SARS-CoV-2 virus replication by blocking the ATP and inhibiting the enzyme function.

Gelsemium elegans Benth: Chemical Components, Pharmacological Effects, and Toxicity Mechanisms.

Gelsemium elegans Benth (GEB), also known as heartbreak grass, is a highly poisonous plant belonging to the family Loganiaceae and genus Gelsemium that has broad application prospects in medicine. This article reviews its chemical components, pharmacological effects, toxicity mechanisms, and research progress in clinical applications in recent years. Indole alkaloids are the main active components of GEB and have a variety of pharmacological and biological functions. They have anti-tumor, anti-inflammatory, analgesic, and immunomodulation properties, with the therapeutic dose being close to the toxic dose. Application of small-dose indole alkaloids fails to work effectively, while high-dose usage is prone to poisoning, aggravating the patient's conditions. Special caution is needed, especially to observe the changes in the disease condition of the patients in clinical practice. In-depth research on the chemical components and mechanisms of GEB is essential to the development of promising lead compounds and lays the foundation for extensive clinical application and safe usage of GEB in the future.

Endemic Xanthium strumarium poisoning in cattle in flooded areas of the Araguari River, Minas Gerais, Brazil.

In this paper, we describe poisoning outbreaks of Xanthium strumarium in cattle on the borders of the Araguari River, Southeastern Brazil. In this region, several hydroelectric plants promote transient flooding, which creates a favorable environment for the invasion of X. strumarium in extensive areas, often as the predominant species in those areas. The outbreaks occurred between July and September (dry season). Bovines of all ages were affected, including suckling animals. Mortality varied from 2% to 5.5%. The animals exhibited ataxia, weakness, loss of balance, recumbency, and the majority were found dead. Laboratory results showed a marked increase in the serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase. Histological and ultrastructural changes in the liver consisted of centrilobular necrosis and hemorrhage. On toxicological evaluation, the dicotyledons contained 0.30 µg/mg of atractyloside and 0.37 µg/mg of carboxyatractyloside. Considerable economic loss has occurred in this region due to the lack of knowledge regarding X. strumarium as a toxic plant and its adaptation to the environmental and climatic conditions of the region, which have made the condition endemic.

Identification and Functional Characterization of Plant Toxins.

The evolutionary arms race between plants and herbivores has led, over millions of years, to the production of many substances that prevent plants from being over-eaten by plant-feeding animals [...].

Extracts Prepared from a Canadian Toxic Plant Induce Light-Dependent Perinuclear Vacuoles in Human Cells.

We are investigating plant species from the Canadian prairie ecological zone by phenotypic cell assays to discover toxins of biological interest. We provide the first report of the effects of extracts prepared from the shrub Symphoricarpos occidentalis in several human cell lines. S. occidentalis (Caprifoliaceae) extracts are cytotoxic, and, strikingly, treated cells undergo light-dependent vacuolation near the nucleus. The range of irradiation is present in standard ambient light and lies in the visible range (400-700 nm). Vacuolization in treated cells can be induced with specific wavelengths of 408 or 660 nm at 1 J/cm2 energies. Vacuolated cells show a striking phenotype of a large perinuclear vacuole (nuclear associated vacuole, NAV) that is distinct from vesicles observed by treatment with an autophagy-inducing agent. Treatment with S. occidentalis extracts and light induces an intense lamin A/C signal at the junction of a nuclear vacuole and the nucleus. Further study of S. occidentalis extracts and vacuolation provide chemical tools that may contribute to the understanding of nuclear envelope organization and human cell biology.

Cannabis: A Toxin-Producing Plant with Potential Therapeutic Uses.

For thousands of years, Cannabis sativa has been utilized as a medicine and for recreational and spiritual purposes. Phytocannabinoids are a family of compounds that are found in the cannabis plant, which is known for its psychotogenic and euphoric effects; the main psychotropic constituent of cannabis is Δ9-tetrahydrocannabinol (Δ9-THC). The pharmacological effects of cannabinoids are a result of interactions between those compounds and cannabinoid receptors, CB1 and CB2, located in many parts of the human body. Cannabis is used as a therapeutic agent for treating pain and emesis. Some cannabinoids are clinically applied for treating chronic pain, particularly cancer and multiple sclerosis-associated pain, for appetite stimulation and anti-emesis in HIV/AIDS and cancer patients, and for spasticity treatment in multiple sclerosis and epilepsy patients. Medical cannabis varies from recreational cannabis in the chemical content of THC and cannabidiol (CBD), modes of administration, and safety. Despite the therapeutic effects of cannabis, exposure to high concentrations of THC, the main compound that is responsible for most of the intoxicating effects experienced by users, could lead to psychological events and adverse effects that affect almost all body systems, such as neurological (dizziness, drowsiness, seizures, coma, and others), ophthalmological (mydriasis and conjunctival hyperemia), cardiovascular (tachycardia and arterial hypertension), and gastrointestinal (nausea, vomiting, and thirst), mainly associated with recreational use. Cannabis toxicity in children is more concerning and can cause serious adverse effects such as acute neurological symptoms (stupor), lethargy, seizures, and even coma. More countries are legalizing the commercial production and sale of cannabis for medicinal use, and some for recreational use as well. Liberalization of cannabis laws has led to increased incidence of toxicity, hyperemesis syndrome, lung disease cardiovascular disease, reduced fertility, tolerance, and dependence with chronic prolonged use. This review focuses on the potential therapeutic effects of cannabis and cannabinoids, as well as the acute and chronic toxic effects of cannabis use on various body systems.

The effect of Ipomoea carnea on maternal reproductive outcomes and fetal and postnatal development in rats.

Ipomoea carnea is a toxic plant found in Brazil and other tropical countries. The plant contains the alkaloids calystegines and swainsonine, which inhibit key cellular enzymes and cause systematic cell death. It is known that swainsonine is excreted in the amniotic fluid of dams exposed to the plant. Thus, the aim of this study was to verify whether the toxic effect of I. carnea on fetuses is due to exclusively the passage of the active principle of the plant through the placenta, or if the placentotoxic effect of swainsonine could collaborate in the adverse effects observed in the fetus. The teratogenic effects of exposure to the toxic principles of I. carnea were evaluated not only using the conventional protocol but also at later stages in the postnatal developmental period. Females were treated, from gestation day (GD) 6 until GD19, with 0.0, 1.0, 3.0 or 7.0 g/kg body weight of I. carnea dry leaves. The plant did not induce changes in reproductive performance or biochemical profile of the dams. Dams that received the highest dose of I. carnea showed cytoplasmic vacuolization in the liver, kidney and placental tissue. I. carnea promoted different lectin binding patterns in different areas of placental tissue. No fetal skeletal or visceral malformations was observed. The postnatal evaluation revealed a lower litter weight and a lower pup body weight one day after birth in the group that received the highest dose of I. carnea. Physical milestones were unaffected by the treatments. Female pups from all experimental groups exhibited a delay in achieving a negative geotaxis response. The results show that the toxic principle of I. carnea produces injury in utero in mothers and fetuses, but these deleterious effects were better demonstrated using postnatal evaluation.

Three poisonous plants (Oenanthe, Cicuta and Anamirta) that antagonise the effect of γ-aminobutyric acid in human brain.

Although we are familiar with common British plants that are poisonous, such as Atropa belladonna (deadly nightshade) and Aconitum napellus (monkshood), the two most poisonous plants in the British Flora are Oenanthe crocata (dead man's fingers) and Cicuta virosa (cowbane). In recent years their poisons have been shown to be polyacetylenes (n-C2H2). The plants closely resemble two of the most common plants in the family Apiaceae (Umbelliferae), celery and parsley. Unwittingly, they are ingested by naive foragers and death occurs very rapidly. The third plant Anamirta derives from South-East Asia and contains a powerful convulsant, picrotoxin, which has been used from time immemorial to catch fish, and more recently to poison Birds of Paradise. All three poisons have been shown to block the γ-aminobutyric acid (GABA) system in the human brain that normally has a powerful inhibitory neuronal action. It has also been established that two groups of sedative drugs, barbiturates and benzodiazepines, exert their inhibitory action by stimulating the GABA system. These drugs are the treatments of choice for poisoning by the three vicious plants.

Neuroprotective and Anti-Neuroinflammatory Effects of a Poisonous Plant Croton Tiglium Linn. Extract.

Neuroinflammation is involved in various neurological diseases. Activated microglia secrete many pro-inflammatory factors and induce neuronal cell death. Thus, the inhibition of excessive proinflammatory activity of microglia leads to a therapeutic effect that alleviates the progression of neuronal degeneration. In this study, we investigated the effect of Croton tiglium(C. tiglium) Linn. extract (CTE) on the production of pro- and anti-inflammatory mediators in microglia and astrocytes via RT-PCR, Western blot, and nitric oxide assay. Neurotoxicity was measured by cell viability assay and GFP image analysis. Phagocytosis of microglia was measured using fluorescent zymosan particles. CTE significantly inhibited the production of neurotoxic inflammatory factors, including nitric oxide and tumor necrosis factor-α. In addition, CTE increased the production of the neurotrophic factor, brain-derived neurotrophic factor, and the M2 phenotype of microglia. The culture medium retained after CTE treatment increased the survival of neurons, thereby indicating the neuroprotective effect of CTE. Our findings indicated that CTE inhibited pro-inflammatory response and increased the neuroprotective ability of microglia. In conclusion, although CTE is known to be a poisonous plant and listed on the FDA poisonous plant database, it can be used as a medicine if the amount is properly controlled. Our results suggested the potential benefits of CTE as a therapeutic agent for different neurodegenerative disorders involving neuroinflammation.

The acute toxicity of water hemlock (Cicuta douglasii) in a goat model.

Water hemlock (Cicuta douglasii) is one of the most toxic plants to livestock and humans. Little is known regarding the amount of plant required to cause death. The objective of this study was to determine a lethal dose of water hemlock in a goat model. Plants were dosed to goats via oral gavage of freeze-dried ground plant material. The results from this study suggest that 1-2 fresh tubers would be lethal to goats.

Arrhythmogenic foods - A growing medical problem.

Arrhythmogenic ingredients in our diet such as mushrooms, licorice, toxic honey, liquid protein drinks, etc. have long been recognized as rare but important considerations in the differential diagnosis of arrhythmias. Anecdotal reports of torsades de pointes (TdP), arrhythmias and/or sudden death and small studies in normal subjects have suggested that simple ingredients such as grapefruit juice or ingredients in energy drinks marketed as dietary supplements could have direct arrhythmogenic actions, especially in patients with congenital long QT syndrome (cLQTS). Two recent studies that employed the industry-standard "thorough QT" trial design leave no doubt that grapefruit juice and some energy drinks can prolong the QTc interval and to exceed 500 msec. in some patients with cLQTS, a threshold known to signal imminent danger. These reports raise numerous clinically important questions such as which other patients may be at risk of arrhythmias. For example, patients with multiple clinical risk factors for TdP (hypokalemia, bradycardia, female sex, etc.) may be at risk from these and possibly other dietary ingredients ingested by millions of people each day. It is essential that further research evaluate the safety of these and similar food products and that vulnerable patients, especially those with cLQTS, be warned of this serious and emerging threat.

Transcriptomics of monarch butterflies (Danaus plexippus) reveals that toxic host plants alter expression of detoxification genes and down-regulate a small number of immune genes.

Herbivorous insects have evolved many mechanisms to overcome plant chemical defences, including detoxification and sequestration. Herbivores may also use toxic plants to reduce parasite infection. Plant toxins could directly interfere with parasites or could enhance endogenous immunity. Alternatively, plant toxins could favour down-regulation of endogenous immunity by providing an alternative (exogenous) defence against parasitism. However, studies on genomewide transcriptomic responses to plant defences and the interplay between plant toxicity and parasite infection remain rare. Monarch butterflies (Danaus plexippus) are specialist herbivores of milkweeds (Asclepias spp.), which contain toxic cardenolides. Monarchs have adapted to cardenolides through multiple resistance mechanisms and can sequester cardenolides to defend against bird predators. In addition, high-cardenolide milkweeds confer monarch resistance to a specialist protozoan parasite (Ophryocystis elektroscirrha). We used this system to study the interplay between the effects of plant toxicity and parasite infection on global gene expression. We compared transcriptional profiles between parasite-infected and uninfected monarch larvae reared on two milkweed species. Our results demonstrate that monarch differentially express several hundred genes when feeding on A. curassavica and A. incarnata, two species that differ substantially in cardenolide concentrations. These differentially expressed genes include genes within multiple families of canonical insect detoxification genes, suggesting that they play a role in monarch toxin resistance and sequestration. Interestingly, we found little transcriptional response to infection. However, parasite growth was reduced in monarchs reared on A. curassavica, and in these monarchs, several immune genes were down-regulated, consistent with the hypothesis that medicinal plants can reduce reliance on endogenous immunity.

NMR-based metabolomics and bioassays to study phytotoxic extracts and putative phytotoxins from Mediterranean plant species.

INTRODUCTION: Mediterranean plants are characterised by a high content of bioactive secondary metabolites that play important roles in plant-plant interactions as plant growth regulators and could be useful for the development of new eco-friendly herbicides. OBJECTIVE: An NMR-based metabolomics approach was reported to seek selective phytotoxic plant extracts and putative plant-derived active molecules. METHODS: Plant extracts derived from five Mediterranean donor species (Pistacia lentiscus, Bellis sylvestris, Phleum subulatum, Petrohrhagia saxifraga and Melilotus neapolitana) were used to treat the hydroponic cultures of three receiving plants (Triticum durum, Triticum ovatum and Avena fatua). Morphological analyses of the treated receiving plants were carried out. NMR-based metabolomics was applied both to characterise the donor plant extracts and to study the effects of the treatments on the receiving plants. RESULTS: This study allowed the identification of Melilotus neapolitana and Bellis sylvestris as phytotoxic plant and good candidates for further studies. Specifically, the NMR-based metabolomics investigation showed that these species affect a specific set of metabolites (such as sugars, amino and organic acids) and therefore metabolic pathways [i.e. tricarboxylic acid (TCA) cycle, amino acid metabolism, etc.] that are crucial for the plant growth and development. Moreover, it was possible to identify the metabolite(s) probably responsible for the phytotoxicity of the active extracts. CONCLUSION: The NMR-based metabolomics approach employed in this study led to the identification of two phytotoxic plant extracts and their putative active principles. These new insights will be of paramount importance in the future to find plant derived molecules endowed with phytotoxic activities.

Poisoning by toxic plants in Hong Kong: a 15-year review.

INTRODUCTION: Hong Kong has a great diversity of plants, many of which are toxic to humans. The aim of this study was to identify the plant species most commonly involved in cases of plant poisoning in Hong Kong and to provide clinicians with a reference tool for the diagnosis and management of plant poisoning. METHODS: We retrospectively reviewed all plant poisoning cases referred to the Hospital Authority Toxicology Reference Laboratory from 1 January 2003 to 31 December 2017. Demographics, clinical presentation, laboratory findings, treatment and outcomes of patients, as well as morphological identification and analytical testing of the plant specimens, were investigated. RESULTS: A total of 62 cases involving 26 poisonous plant species were identified, among which Alocasia macrorrhizos (Giant Alocasia), Gelsemium elegans (Graceful Jessamine), and Rhododendron (Azalea) species were the three most commonly encountered. Gastrointestinal toxicity (n=30, 48%), neurological toxicity (n=22, 35%), and hepatotoxicity (n=6, 10%) were the three most common clinical problems. Forty-nine (79%) and eight (13%) patients had mild and moderate toxicity, respectively; they all recovered shortly with supportive treatment. The remaining five (8%) patients experienced severe toxicity requiring intensive care support. Most patients (n=61, 98%) used the plants intentionally: as a medicinal herb (n=31), as food (n=29), and for attempting suicide (n=1). Reasons for using the poisonous plants included misidentification (n=34, 55%), unawareness of the toxicity (n=20, 32%), and contamination (n=6, 10%). CONCLUSIONS: Although most plant exposure resulted in a self-limiting disease, severe poisonings were encountered. Epidemiology of plant poisonings is geographically specific. Clinicians should be aware of local poisonous plants and their toxicities.