Amanitins: The Most Poisonous Molecules of the Fungal World.

Among the toxic metabolites of the fungal world, those that, due to their strong biological effect, can seriously (even fatally) damage the life processes of humans (and certain groups of animals) stand out. Amatoxin-containing mushrooms and the poisonings caused by them stand out from the higher fungi, the mushrooms. There are already historical data and records about such poisonings, but scientific research on the responsible molecules began in the middle of the last century. The goals of this review work are as follows: presentation of the cosmopolitan mushroom species that produce amanitins (which are known from certain genera of four mushroom families), an overview of the chemical structure and specific properties of amanitins, a summary of the analytical methods applicable to them, a presentation of the "medical history" of poisonings, and a summary of the therapeutic methods used so far. The main responsible molecules (the amanitins) are bicyclic octapeptides, whose structure is characterized by an outer loop and an inner loop (bridge). It follows from the unusual properties of amanitins, especially their extreme stability (against heat, the acidic pH of the medium, and their resistance to human, and animal, digestive enzymes), that they are absorbed almost without hindrance and quickly transported to our vital organs. Adding to the problems is that accidental consumption causes no noticeable symptoms for a few hours (or even 24-36 h) after consumption, but the toxins already damage the metabolism of the target organs and the synthesis of nucleic acid and proteins. The biochemical catastrophe of the cells causes irreversible structural changes, which lead to necrotic damage (in the liver and kidneys) and death. The scientific topicality of the review is due to the recent publication of new data on the probable antidote molecule (ICR: indocyanine green) against amanitins. Further research can provide a new foundation for the therapeutic treatment of poisonings, and the toxicological situation, which currently still poses a deadly threat, could even be tamed into a controllable problem. We also draw attention to the review conclusions, as well as the mycological and social tasks related to amanitin poisonings (prevention of poisonings).

[Color Reaction Identification of Omphalotus guepiniformis Causing Food Poisoning].

Simple identification using a color reaction was applied to investigate poisoning, putatively caused by Omphalotus guepiniformis. Some leftover uncooked mushrooms had turned turquoise green when a beam reagent (5 w/v% potassium hydroxide ethanolic solution) was dripped onto the mushroom pileus. Furthermore, ethanol extract of the mushrooms exhibited the same color reaction. Then, illudin S, a toxic compound contained in O. guepiniformis, was detected in uncooked leftover mushrooms using LC-MS/MS analysis. Therefore, this case was inferred as caused by O. guepiniformis. These results indicate the identification method described above as useful for screening tests for investigating food poisoning caused by O. guepiniformis.

Demographic, clinical, and laboratory findings of mushroom-poisoned patients in Kermanshah province, west of Iran.

BACKGROUND: Mushroom poisoning can cause gastrointestinal, renal, and hepatic symptoms and even death. This descriptive study examined the demographic, clinical, and laboratory findings of patients with fungal poisoning, a type of fungus causing the poisoning, and the incidence and mortality rates of fungal poisoning in Kermanshah province, western Iran, from 2014 to 2018. METHODS: The medical records of 193 patients with mushroom poisoning from 2014 to 2018 were evaluated. The liver and kidney function tests, electrolytes, abdominal and pelvic ultrasound, chest x-ray, coagulation tests, and coagulation factors (fibrinogen, prothrombin) were assessed. Data were collected from the medical records of patients admitted to the Poisoning Center of Imam Khomeini Hospital in Kermanshah, Iran using a researcher-made checklist. Data were analyzed by SPSS (version 16) using descriptive statistics, including mean, standard deviation, and frequency distribution tables. Trend analysis for proportion was done by chi-square statistics in STATA-14 software (ptrend command). RESULTS: Of cases, |51.3% were male, 92.6% were city dwellers, 38.3% were aged 21-40 years, and 92.5% were poisoned during the spring. The fungus that caused poisoning was Amanita virosa. The gastrointestinal, nervous, and visual systems were the most common systems involved. The most common gastrointestinal symptoms included nausea and vomiting (72.0%) and abdominal pain (71.0%). Vertigo (11.9%) and headache (9.3%) were the most common neurological symptoms. The most common visual manifestation was blurred vision (7.8%). Of cases, 23.7% had metabolic acidosis. The increased alkaline phosphatase level was the most common liver disorder in 98.7% of the cases. Increased blood urea nitrogen and creatinine levels were also reported in 21.0% and 17.7% of the cases, respectively. The serum lactic dehydrogenase and creatine phosphokinase levels also increased in 99.3% and 30.2% of the patients, respectively. The mortality rate was 1.6% (n = 3). CONCLUSION: The fungal poisoning diagnosis should always be considered in young patients referred to the emergency department with gastrointestinal complaints, a history of consuming wild self-picked mushrooms, and high liver and kidney test values. Since most fungal poisonings occur in the spring, it is necessary to inform the community of the dangers of consuming self-picked wild mushrooms, especially in this season.

Non-peptide secondary metabolites from poisonous mushrooms: overview of chemistry, bioactivity, and biosynthesis.

Covering: up to June 2021A wide variety of mushrooms have traditionally been recognized as edible fungi with high nutritional value and low calories, and abundantly produce structurally diverse and bioactive secondary metabolites. However, accidental ingestion of poisonous mushrooms can result in serious illnesses and even death. Chemically, mushroom poisoning is associated with secondary metabolites produced in poisonous mushrooms, causing specific toxicity. However, many poisonous mushrooms have not been fully investigated for their secondary metabolites, and the secondary metabolites of poisonous mushrooms have not been systematically summarized for details such as chemical composition and biosynthetic mechanisms. The isolation and identification of secondary metabolites from poisonous mushrooms have great research value since these compounds could be lethal toxins that contribute to the toxicity of mushrooms or could provide lead compounds with remarkable biological activities that can promote advances in other related disciplines, such as biochemistry and pharmacology. In this review, we summarize the structures and biological activities of secondary metabolites identified from poisonous mushrooms and provide an overview of the current information on these metabolites, focusing on their chemistry, bioactivity, and biosynthesis.

Nephrotoxic Mushroom Poisoning: Global Epidemiology, Clinical Manifestations, and Management.

Because mushroom poisonings are increasing worldwide after ingestions of known, newly described, and formerly considered edible species, the objectives of this review are to describe the global epidemiology of nephrotoxic mushroom poisonings, to identify nephrotoxic mushrooms, to present a toxidromic approach to earlier diagnoses of nephrotoxic mushroom poisonings based on the onset of acute renal failure, and to compare the outcomes of renal replacement management strategies. Internet search engines were queried with the keywords to identify scientific articles on nephrotoxic mushroom poisonings and their management during the period of 1957 to the present. Although hepatotoxic, amatoxin-containing mushrooms cause most mushroom poisonings and fatalities, nephrotoxic mushrooms, most commonly Cortinarius species, can cause acute renal insufficiency and failure. Several new species of nephrotoxic mushrooms have been identified, including Amanita proxima and Tricholoma equestre in Europe and Amanita smithiana in the United States and Canada. In addition, the edible, hallucinogenic mushroom Psilocybe cubensis has been noted recently via mass spectrometry as a rare cause of acute renal insufficiency. Renal replacement therapies including hemodialysis are often indicated in the management of nephrotoxic mushroom poisonings, with renal transplantation reserved for extracorporeal treatment failures.

Chemistry and Toxicology of Major Bioactive Substances in Inocybe Mushrooms.

Mushroom poisoning has always been a threat to human health. There are a large number of reports about ingestion of poisonous mushrooms every year around the world. It attracts the attention of researchers, especially in the aspects of toxin composition, toxic mechanism and toxin application in poisonous mushroom. Inocybe is a large genus of mushrooms and contains toxic substances including muscarine, psilocybin, psilocin, aeruginascin, lectins and baeocystin. In order to prevent and remedy mushroom poisoning, it is significant to clarify the toxic effects and mechanisms of these bioactive substances. In this review article, we summarize the chemistry, most known toxic effects and mechanisms of major toxic substances in Inocybe mushrooms, especially muscarine, psilocybin and psilocin. Their available toxicity data (different species, different administration routes) published formerly are also summarized. In addition, the treatment and medical application of these toxic substances in Inocybe mushrooms are also discussed. We hope that this review will help understanding of the chemistry and toxicology of Inocybe mushrooms as well as the potential clinical application of its bioactive substances to benefit human beings.

Ground Glass-Like Inclusions: Associated with Liver Toxicity.

OBJECTIVE: The etiology of ground glass-like inclusions is heterogenous and the pathology has been described in various conditions including HBV infection, Lafora's disease, fibrinogen storage disease, type IV glycogenosis, and alcohol reversion therapy. Similar ground glass-like inclusions are also associated with immunosuppressed conditions and multiple medications, for which the clinical significance is still unclear. Additional cases, some with previously unreported unique etiologies, and their follow-up were described in this study. MATERIALS AND METHODS: Eleven cases were examined between 2008 and 2019 for this study. The clinical data and histologic slides were reviewed. All of the cases were negative for Hepatitis B virus. None of the patients declared alcohol intake or a history of epilepsy. RESULTS: Liver histology showed mild lobular inflammation in most of the cases (72%). Ground glass-like hepatocytes were distributed in the patchy-panlobular, periportal, and centrizonal pattern at 55%, 27%, and 18%, respectively. Clinical history revealed medication use in nine (82%) patients including NSAIDs, steroids, and chemotherapy. Ground glass-like inclusions were related to herbal toxicity in two of the patients. Liver function tests were elevated in all of the cases. Follow-up data revealed four patients with malignancy who died of their cancer. Seven patients showed resolution of elevated liver enzymes with a median follow-up period of 37 months (range 7-132 months). CONCLUSIONS: Medication is the most relevant etiology for the development of these inclusions. Ground glass-like inclusions may also seen in herbal toxicity. Transplantation was not an etiologic factor in our patients. Most of the patients displayed an indolent course with resolution of the elevated transaminases.

Energy disorders caused by mitochondrial dysfunction contribute to α-amatoxin-induced liver function damage and liver failure.

Mushroom toxicity is the main branch of foodborne poisoning, and liver damage caused by amatoxin poisoning accounts for more than 90 % of deaths due to mushroom poisoning. Alpha-amatoxin (α-AMA) has been considered the primary toxin from amatoxin-containing mushrooms, which is responsible for hepatotoxicity and death. However, the mechanism underlying liver failure due to α-AMA remains unclear. This study constructed animal and cell models. In the animal experiments, we investigated liver injury in BALB/c mice at different time points after α-AMA treatment, and explored the process of inflammatory infiltration using immunohistochemistry and western blotting. Then, a metabonomics method based on gas chromatography mass spectrometry (GCMS) was established to study the effect of α-AMA on liver metabonomics. The results showed a significant difference in liver metabolism between the exposed and control mice groups that coincided with pathological and biochemical indicators. Moreover, 20 metabolites and 4 metabolic pathways related to its mechanism of action were identified, which suggested that energy disorders related to mitochondrial dysfunction may be one of the causes of death. The significant changes of trehalose and the fluctuation of LC3-II and sqstm1 p62 protein levels indicated that autophagy was also involved in the damage process, suggesting that autophagy may participate in the clearance process of damaged mitochondria after poisoning. Then, we constructed an α-AMA-induced human normal liver cells (L-02 cells) injury model. The above hypothesis was further verified by detecting cell necrosis, mitochondrial reactive oxygen species (mtROS), mitochondrial permeability transition pore (mPTP) opening, mitochondrial membrane potential (Δψ m), and cellular ATP level. Collectively, our results serve as direct evidence of elevated in vivo hepatic mitochondrial metabolism in α-AMA-exposed mice and suggest that mitochondrial dysfunction plays an important role in the early stage of α-AMA induced liver failure.

Toxic Potential of Traditionally Consumed Mushroom Species-A Controversial Continuum with Many Unanswered Questions.

Mushroom poisonings remain a significant cause of emergency medicine. While there are well-known species, such as Amanita phalloides, causing life-threatening poisonings, there is also accumulating evidence of poisonings related to species that have been considered edible and are traditionally consumed. In particular, the Tricholoma equestre group was reported to cause myotoxicity. In addition, particular wild mushrooms that are traditionally consumed especially in Asia and Eastern Europe have been subject to suspicion due to possible mutagenicity. Hitherto, the causative agents of these effects often remain to be determined, and toxicity studies have yielded contradictory results. Due to this, there is no consensus about the safety of these species. The issue is further complicated by difficulties in species identification and other possible sources of toxicity, such as microbiological contamination during storage, leading to sometimes opposite conclusions about the edibility of a species. This review focuses on existing data about these types of mushroom poisonings, including the still sparse knowledge about the causative chemical agents. In addition, the aim is to initiate a meta-discussion about the issue and to give some suggestions about how to approach the situation from the viewpoint of the collector, the researcher, and the practicing physician.

Low-cost management of mushroom poisoning in a limited-resource area: a 12-year retrospective study.

Amatoxin poisoning is the main cause of death from accidental ingestion of poisonous mushrooms and a mortality rate of 27.3% has been reported in Thailand. Symptoms of mushroom ingestion are often confused with food poisoning; thus, gastroenteritis is not recognised as the first phase of poisoning. Our study assessed the efficacy of N-acetylcysteine (NAC) as a treatment for amatoxin poisoning. We retrospectively analysed 74 medical records over 12 years. The majority (70/74) were treated successfully with NAC; death in the remaining 4 (5.4%) patients was attributed to late presentation in three and advanced alcoholic cirrhosis in one.

Toxicity of muscimol and ibotenic acid containing mushrooms reported to a regional poison control center from 2002-2016.

BACKGROUND: Amanita muscaria (AM) and A. pantherina (AP) contain ibotenic acid and muscimol and may cause both excitatory and sedating symptoms. Gastrointestinal (GI) symptoms are not classically described but have been reported. There are relatively few reported cases of poisoning with these mushrooms in North America. METHODS: This is a retrospective review of ingestions of ibotenic acid and muscimol containing mushrooms reported to a United States regional poison center from 2002-2016. Cases were included if identification was made by a mycologist or if AM was clearly described. RESULTS: Thirty-four cases met inclusion criteria. There were 23 cases of AM, 10 AP, and 1 A. aprica. Reason for ingestion included foraging (12), recreational (6), accidental (12), therapeutic (1), self-harm (1), and unknown (2). Of the accidental pediatric ingestions 4 (25%) were symptomatic. None of the children with a symptomatic ingestion of AM required admission. A 3-year-old male who ingested AP had vomiting, agitation, and lethargy and received benzodiazepines. He was intubated and had a 3-day ICU stay. There were 25 symptomatic patients. All but one patient developed symptoms within 6 h. Six patients had symptoms for less than 6 h while 15 had symptoms lasting less than 24 h. Ingestions of AP were more symptomatic than AM with regard to the presence of any GI symptoms (80% vs. 35%), central nervous system (CNS) depression (70% vs. 35%), and CNS excitation (70% vs. 35%) respectively. Five patients were intubated. No patients experienced hypotension, seizures, acute kidney injury, or hepatotoxicity. No deaths were reported. DISCUSSION: Ingestion of ibotenic acid/muscimol containing mushrooms often produces a syndrome with GI upset, CNS excitation, and CNS depression either alone or in combination. Ingestion of AP was associated with a higher rate of symptoms compared to AM.

Investigation and analysis of Galerina sulciceps poisoning in a canteen.

INTRODUCTION: Guizhou Province in China has an abundant resource of wild mushrooms, including numerous poisonous species which contain various toxins. The mortality rate from wild mushroom poisoning has been high in this area in recent years. Galerina sulciceps is a dangerously toxic mushroom which can be fatal if ingested. METHODS: we report on an epidemiological investigation of G. sulciceps poisoning which occurred in Duyun City of Guizhou Province. The characteristics of this species, its toxicity, observed clinical features, laboratory data, treatment modality, and prognosis were investigated in order to provide a reference point for the prevention and treatment of this kind of mushroom poisoning. RESULTS: Thirteen employees showed toxic symptoms after ingesting wild mushrooms the previous day in a company canteen. Clinical manifestation varied from gastroenteritis to hepatic and renal dysfunction. Most of the 13 patients presented with nausea, vomiting, abdominal pain, diarrhea, and elevated levels of biochemical indices of hepatic and renal function, during which transaminase concentration peaked within 48-72 h. At 48 hours post-ingestion, all patients had hemodialysis, in addition to supportive care for hepatic and renal injury with oral Silibinin and Shenshuaining. All acute renal injury had resolved by day 10, and liver transaminases had trended toward normal in all patients and they were discharged. At follow-up in 30 days, both liver and renal function had completely recovered in all. CONCLUSION: This poisoning occurs as a result of unintentional consumption of G. sulciceps, which is relatively rare in mushroom poisonings. All patients recovered fully after timely diagnosis and treatment. To prevent wild mushroom poisoning, the best preventive measure is to educate the public not to gather and eat any unidentified wild mushrooms.

Rapid LC-MS Determination of Acromelic Acids A and B, Toxic Constituents of the Mushroom Paralepistopsis acromelalga.

A rapid LC-MS method was developed for determination of acromelic acids A and B, which are toxic constituents of Paralepistopsis acromelalga (=Clitocybe acromelalga), in mushroom samples. Acromelic acids were extracted twice with 50% methanol and the extract was passed through a syringe filter, and then analyzed by LC-MS. The LC separation was performed on a multi-mode ODS column. The recoveries of acromelic acids A and B spiked into blank mushroom samples at 2.5 µg/g were 93 and 74%, respectively. This method was applied to the remaining mushroom sample from a food poisoning case. Acromelic acids A and B were detected at 2.0 and 1.4 µg/g, respectively, in the remaining sample. Another toxic constituent, which appeared to be clitidine, was also detected in the sample.

Rapid Identification Method of Omphalotus japonicus by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).

Omphalotus japonicus is a poisonous mushroom that grows in Japan. It can be mistaken for edible mushrooms (Shiitake, Hiratake and Mukitake), and if ingested, it causes food poisoning within 30 min to 1 hr. We established a rapid detection method using PCR-RFLP to identify O. japonicus by restriction digestion of the amplified ITS region. By using Sau96I, Bpu10I, SfcI or DrdI/HincII as a restriction enzyme, it was possible to rapidly identify and discriminate O. japonicus based on the fragment length. This study also provided a short PCR-RFLP system comprising amplification and digestion of a short 200-bp DNA fragment within the ITS region. The system could identify and discriminate O. japonicus after in vitro gastric digestion of native and heated mushroom samples as a model of food poisoning. In addition, a confirmatory assay using real-time PCR was developed to achieve more sensitive detection of O. japonicus.

Clinical features of shiitake dermatitis: a systematic review.

Shiitake dermatitis is a rare cutaneous reaction to lentinan, a polysaccharide component in the cell walls of shiitake mushrooms (Lentinula edodes). Herein, we systematically review the case report and case series English-language literature on shiitake dermatitis, which refers to a total of 50 patients (38 males, 12 females; mean age: 44.58 years). The majority of cases occurred after the consumption of raw mushrooms, whereas 22% of cases were caused by the eating of lightly or undercooked mushrooms. The most common clinical presentations, localized symptoms, and systemic findings include linear flagellated dermatitis (98%), pruritus (78%), and fever, diarrhea, and mucosal ulcers, respectively. The diagnosis of this entity continues to be based on clinical findings as laboratory abnormalities, and the findings of skin biopsies and patch/prick tests are nonspecific and inconsistent. The condition is self-limiting, resolving in approximately 12.5 d without treatment. Based on the included case reports, it appears that medical treatment may slightly shorten the course of disease (to 9-11 d, varying by therapy) but should be considered on an individual patient basis. However, the treatment of symptoms, reassurance, and the avoidance of re-exposure are sufficient treatment recommendations for this condition.

Eritema flagelado por ingesta de hongos Shiitake: reporte de caso / Flagellated erythema due to Shiitake mushroom intake: report of case

El eritema flagelado es una erupción cutánea poco frecuente con múltiples causas, dentro de las cuales se encuentra la ingesta de hongos shiitake crudos o semicrudos. Se postula que es secundario a una reacción de hipersensibilidad Th-1 producida por el lentinan, un polisacárido termolábil de la pared celular del hongo. En años recientes ha aumentado su incidencia en el mundo occidental debido a la creciente popularidad de la comida asiática, en la que los hongos shiitake son un ingrediente muy utilizado. El cuadro clínico se caracteriza por la aparición de lesiones eritematosas lineales pruriginosas principalmente en tronco y extremidades, de curso autolimitado. El diagnóstico es principalmente clínico, basado en el antecedente de ingesta reciente de hongos shiitake y el rash característico y el tratamiento es sintomático con antihistamínicos y corticoides tópicos u orales. A continuación, presentamos un caso de eritema flagelado en una mujer joven, secundario a ingesta de hongos shiitake, que se resolvió completamente en 2 semanas.

Flagellate erythema is a rare skin eruption with many causes, including the ingestion of raw or undercooked shiitake mushrooms. It is thought to be a Th-1 hypersensitivity reaction produced by lentinan, a thermolabile polysaccharide found in the cell wall of the mushroom. In recent years, there has been an increase in the number of cases due to the growing popularity of Asian cuisine, in which shiitake mushrooms are a central ingredient. The clinical presentation is characterized by the appearance of linear, erythematous, pruritic lesions mostly on the trunk and extremities, of self-limited course. Diagnosis is mainly clinical, based on the history of recent shiitake mushroom ingestion and the characteristic rash, and treatment is symptomatic, with antihistamines and topical or systemic steroids. In this report, we present a case of flagellate erythema in a young woman, that appeared after the ingestion of shiitake mushrooms, and resolved completely after 2 weeks.

Identification of Mushroom Species by Automated rRNA Intergenic Spacer Analysis (ARISA) and Its Application to a Suspected Case of Food Poisoning with Tricholoma ustale.

Automated rRNA intergenic spacer analysis (ARISA), a method of microbiome analysis, was evaluated for species identification of mushrooms based on the specific fragment sizes. We used 51 wild mushroom-fruiting bodies collected in the centre of Hokkaido and two cultivated mushrooms. Samples were hot-air-dried and DNA were extracted by a beads beating procedure. Sequencing analysis of portions of the rRNA gene (rDNA) provided 33 identifications of mushrooms by genus or species. The results of ARISA identification based on the combination of the fragment sizes corresponding to two inter spacer regions (ITS2 and ITS1) of rDNA within±0.1% accuracy showed that 27 out of the 33 species had specific fragment sizes differentiated from other species. The remaining 6 species formed 3 pairs that showed overlapping fragment sizes. In addition, within-species polymorphisms were observed as 1 bp differences among 32 samples of 13 species. ARISA was applied to investigate a case of suspected food poisoning in which the mushroom was thought to be a toxic Kakishimeji. The morphological identification of the mushroom was ambiguous since the remaining sample lacked a part of the fruiting body. Further, yeast colonies had grown on the surface of the fruiting body during storage. The ARISA fragment size of the mushroom showed 7 bp difference from that of the candidate toxic mushroom. Although ARISA could be a useful tools for estimation of mushroom species, especially in case where the fruiting bodies have deteriorated or been processed, further studies are necessary for reliable identification. For example, it may be necessary to adopt more informative genes which could provide clearer species-specific polymorphisms than the ITS regions.

[Forensic medical diagnostics of intoxication with certain poisonous mushrooms in the case of the lethal outcome in a hospital].

The present study was undertaken with a view to improving forensic medical diagnostics of intoxication with poisonous mushrooms in the cases of patients' death in a hospital. A total of 15 protocols of forensic medical examination of the corpses of the people who had died from acute poisoning were available for the analysis. The deathly toxins were amanitin and muscarine contained in various combinations in the death cap (Amanita phalloides) and the early false morels (Gyromitra esculenta and G. gigas). The main poisoning season in the former case was May and in the latter case August and September (93.4%). The mortality rate in the case of group intoxication (such cases accounted for 40% of the total) amounted to 28.6%. 40% of the deceased subjects consumed mushrooms together with alcohol. The poisoning caused the development of either phalloidin- or gyromitrin-intoxication syndromes (after consumption of Amanita phalloides and Gyromitra esculenta respectively). It is emphasized that the forensic medical experts must substantiate the diagnosis of poisoning with mushroom toxins based on the results of the chemical-toxicological and/or forensic chemical investigations. The relevant materials taken from the victim or the corpse should be dispatched for analysis not only within the first day but also on days 2-4 after intoxication. The mycological and genetic analysis must include the detection and identification of mushroom microparticles and spores in the smears from the oral cavity, vomiting matter, wash water, gastric and intestinal contents. In addition, the macro- and microscopic morphological signs, clinical data (major syndromes, results of laboratory studies, methods of treatment) should be taken into consideration as well as the time (season) of mushroom gathering, simultaneous poisoning in a group of people, and other pertinent information.