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.

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.

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.

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.

[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.

Amatoxin and phallotoxin concentration in Amanita phalloides spores and tissues.

Most of the fatal cases of mushroom poisoning are caused by Amanita phalloides. The amount of toxin in mushroom varies according to climate and environmental conditions. The aim of this study is to measure α-, ß-, and γ-amanitin with phalloidin and phallacidin toxin concentrations. Six pieces of A. phalloides mushrooms were gathered from a wooded area of Düzce, Turkey, on November 23, 2011. The mushrooms were broken into pieces as spores, mycelium, pileus, gills, stipe, and volva. α-, ß-, and γ-Amanitin with phalloidin and phallacidin were analyzed using reversed-phase high-performance liquid chromatography. As a mobile phase, 50 mM ammonium acetate + acetonitrile (90 + 10, v/v) was used with a flow rate of 1 mL/min. C18 reverse phase column (150 × 4.6 mm; 5 µm particle) was used. The least amount of γ-amanitin toxins was found at the mycelium. The other toxins found to be in the least amount turned out to be the ones at the spores. The maximum amounts of amatoxins and phallotoxin were found at gills and pileus, respectively. In this study, the amount of toxin in the spores of A. phalloides was published for the first time, and this study is pioneering to deal with the amount of toxin in mushrooms grown in Turkey.

A Case Study: What Doses of Amanita phalloides and Amatoxins Are Lethal to Humans?

There are few data estimating the human lethal dose of amatoxins or of the toxin level present in ingested raw poisonous mushrooms. Here, we present a patient who intentionally ingested several wild collected mushrooms to assess whether they were poisonous. Nearly 1 day after ingestion, during which the patient had nausea and vomiting, he presented at the emergency department. His transaminase levels started to increase starting from hour 48 and peaking at hour 72 (alanine aminotransferase 2496 IU/L; aspartate aminotransferase 1777 IU/L). A toxin analysis was carried out on the mushrooms that the patient said he had ingested. With reversed-phase high-performance liquid chromatography analysis, an uptake of approximately 21.3 mg amatoxin from nearly 50 g mushroom was calculated; it consisted of 11.9 mg alpha amanitin, 8.4 mg beta amanitin, and 1 mg gamma amanitin. In the urine sample taken on day 4, 2.7 ng/mL alpha amanitin and 1.25 ng/mL beta amanitin were found, and there was no gamma amanitin. Our findings suggest that the patient ingested approximately 0.32 mg/kg amatoxin, and fortunately recovered after serious hepatotoxicity developed.

Flagellate shiitake mushroom dermatitis.

An 84-year-old woman presented with 5 days of a pruritic skin eruption that formed arciform and linear patterns. She was diagnosed with flagellate shiitake mushroom dermatitis related to shiitake mushroom consumption the day prior symptom onset.

Chaga mushroom-induced oxalate nephropathy.

Chaga mushrooms have been used in folk and botanical medicine as a remedy for cancer, gastritis, ulcers, and tuberculosis of the bones. A 72-year-old Japanese female had been diagnosed with liver cancer 1 year prior to presenting at our department. She underwent hepatectomy of the left lobe 3 months later. Chaga mushroom powder (4 - 5 teaspoons per day) had been ingested for the past 6 months for liver cancer. Renal function decreased and hemodialysis was initiated. Renal biopsy specimens showed diffuse tubular atrophy and interstitial fibrosis. Oxalate crystals were detected in the tubular lumina and urinary sediment and oxalate nephropathy was diagnosed. Chaga mushrooms contain extremely high oxalate concentrations. This is the first report of a case of oxalate nephropathy associated with ingestion of Chaga mushrooms.

Shiitake mushroom-induced flagellate erythema: A striking case and review of the literature.

Ingestion of raw or undercooked shiitake mushrooms is associated with a distinctive flagellate erythema. We describe a 61-year-old Caucasian man who presented with a pruritic, erythematous eruption of multiple linear streaks on the trunk and extremities starting 1 day after eating raw shiitake mushrooms. His symptoms and skin lesions resolved with minimal hyperpigmentation within approximately 1 week after treating with topical steroids and oral antihistamines. Skin biopsy showed non-specific findings, including a sparse perivascular and interstitial dermatitis as well as focal vacuolar interface changes. Our case illustrates that this condition is a visibly striking dermatitis with a self-limited course. The pathomechanism of the skin eruption remains unclear.

[Acute hepatic failure after ingestion of mushrooms]. / Akutes Leberversagen nach Pilzingestion.

This report is about a married couple who were admitted to hospital suffering from gastrointestinal complaints after eating mushrooms. With the suspicion of poisoning with Amanita phalloides treatment started with elimination of the toxins, symptomatic therapy and specific therapy with silibinin. After quantitative determination of the Amanita toxins the patients were immediately transferred to a university hospital.Poisoning by the death cap mushroom is responsible for acute hepatic and often also renal failure and is accompanied by a high mortality. Clinical symptoms follow a three-phase course with gastrointestinal complaints, an asymptomatic interval and finally the hepatorenal phase. Even in suspected cases of intoxication, treatment should be started by antidote therapy with silibinin.

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.

Identification of the toxic trigger in mushroom poisoning.

We have isolated the small, highly strained carboxylic acid cycloprop-2-ene carboxylic acid from the Asian toxic mushroom Russula subnigricans. This compound is responsible for fatal rhabdomyolysis, a new type of mushroom poisoning that is indicated by an increase in serum creatine phosphokinase activity in mice. We found that polymerization of the compound at high concentrations via ene reaction abolishes its toxicity.

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.

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.