Gastrointestinal and hepatic effects of Amanita phalloides ingestion

Amanitin intoxication: effects of therapies on clinical outcomes - a review of 40 years of reported cases

BACKGROUND AND AIMS

Amanita phalloides poisoning causes severe liver damage which may be potentially fatal. Several treatments are available, but their effectiveness has not been systematically evaluated. We performed a systematic review to investigate the effect of the most commonly used therapies: N-acetylcysteine (NAC), benzylpenicillin (PEN), and silibinin (SIL) on patient outcomes. In addition, other factors contributing to patient outcomes are identified.

METHODS

We searched MEDLINE and Embase for case series and case reports that described patient outcomes after poisoning with amanitin-containing Amanita mushrooms. We extracted clinical characteristics, treatment details, and outcomes. We used the liver item from the Poisoning Severity Score (PSS) to categorize intoxication severity.

RESULTS

We included 131 publications describing a total of 877 unique cases. The overall survival rate of all patients was 84%. Patients receiving only supportive care had a survival rate of 59%. The use of SIL or PEN was associated with a 90% (OR 6.40 [3.14-13.04]) and 89% (OR 5.24 [2.87-9.56]) survival rate, respectively. NAC/SIL combination therapy was associated with 85% survival rate (OR 3.85 [2.04, 7.25]). NAC/PEN/SIL treatment group had a survival rate of 76% (OR 2.11 [1.25, 3.57]). Due to the limited number of cases, the use of NAC alone could not be evaluated. Additional analyses in 'proven cases' (amanitin detected), 'probable cases' (mushroom identified by mycologist), and 'possible cases' (neither amanitin detected nor mushroom identified) showed comparable results, but the results did not reach statistical significance. Transplantation-free survivors had significantly lower peak values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total serum bilirubin (TSB), and international normalized ratio (INR) compared to liver transplantation survivors and patients with fatal outcomes. Higher peak PSS was associated with increased mortality.

CONCLUSION

Based on data available, no statistical differences could be observed for the effects of NAC, PEN or SIL in proven poisonings with amanitin-containing mushrooms. However, monotherapy with SIL or PEN and combination therapy with NAC/SIL appear to be associated with higher survival rates compared to supportive care alone. AST, ALT, TSB, and INR values are possible predictors of potentially fatal outcomes.

A rare case of amatoxin poisoning in the state of Texas

Ingestion of mushrooms from the genus Amanita can present detrimental consequences to the human body. The mushroom is frequently found in the coastal Pacific Northwest, Pennsylvania, New Jersey, and Ohio. Amanitin, one of the two distinct toxins isolated from the Amanita mushroom, is responsible for the majority of symptoms and signs seen with mushroom poisoning. Clinically, ingestion of these mushrooms can result in a wide range of clinical symptoms including nausea, vomiting, crampy abdominal pain, and diarrhea. There have been several case reports of patients who developed severe hepatic failure that required liver transplantation. Thus, it is important to recognize the symptoms early and treat the patients with the available agents including multidose activated charcoal, N-acetylcysteine, penicillin G, and Silybum. Through an extensive literature search, we found no published literature on amatoxin poisoning in the state of Texas. With new cases of amatoxin poisoning emerging in the state, it is important for healthcare providers and workers to have a better awareness and early recognition of the detrimental effects of Amanita species poisoning and to be educated to provide the proper care for this group of patients.

Protective effect of bile acid derivatives in phalloidin-induced rat liver toxicity

Phalloidin causes severe liver damage characterized by marked cholestasis, which is due in part to irreversible polymerization of actin filaments. Liver uptake of this toxin through the transporter OATP1B1 is inhibited by the bile acid derivative BALU-1, which does not inhibit the sodium-dependent bile acid transporter NTCP. The aim of the present study was to investigate whether BALU-1 prevents liver uptake of phalloidin without impairing endogenous bile acid handling and hence may have protective effects against the hepatotoxicity induced by this toxin. In anaesthetized rats, i.v. administration of BALU-1 increased bile flow more than taurocholic acid (TCA). Phalloidin administration decreased basal (-60%) and TCA-stimulated bile flow (-55%) without impairing bile acid output. Phalloidin-induced cholestasis was accompanied by liver necrosis, nephrotoxicity and haematuria. In BALU-1-treated animals, phalloidin-induced cholestasis was partially prevented. Moreover haematuria was not observed, which was consistent with histological evidences of BALU-1-prevented injury of liver and kidney tissue. HPLC-MS/MS analysis revealed that BALU-1 was secreted in bile mainly in non-conjugated form, although a small proportion (<5%) of tauro-BALU-1 was detected. BALU-1 did not inhibit the biliary secretion of endogenous bile acids. When highly choleretic bile acids, - ursodeoxycholic (UDCA) and dehydrocholic acid (DHCA) - were administered, they were found less efficient than BALU-1 in preventing phalloidin-induced cholestasis. Biliary phalloidin elimination was low but it was increased by BALU-1>TCA>DHCA>UDCA. In conclusion, BALU-1 is able to protect against phalloidin-induced hepatotoxicity, probably due to an inhibition of the liver uptake and an enhanced biliary secretion of this toxin.

Amanita bisporigera ingestion: mistaken identity, dose-related toxicity, and improvement despite severe hepatotoxicity

Ingestion of wild mushrooms has led to unintentional poisonings caused by mistaken identity. We report 3 cases of exposure to Amanita bisporigera, demonstrating dose-related toxicity. The use of nasobiliary drainage as a novel approach to interrupting the enterohepatic circulation of amatoxins is illustrated. Pathophysiology and treatment of Amanita poisoning are reviewed.

Nephrotoxicity associated with exposure to plant toxins, with particular reference to Africa

Acute renal failure is a frequent cause of morbidity and mortality in the hospitalized population worldwide. In Africa, apart from hemodynamic causes and infections, herbal remedies contribute to both morbidity and mortality, although these causes often go unrecognized. This paper reviews reports of herbal remedies that have been shown to result in nephrotoxicity. The indications for use of the remedies, signs and symptoms in poisoned patients, and the methods used to detect toxic compounds in plant specimens or in biological fluids are covered.

Cytotoxic fungi—an overview

Among fungal toxins causing organ damage in the human body, amatoxins and orellanine remain exceptional. Amatoxins, a group of bicyclic octapeptides occurring in some Amanita, Galerina and Lepiota species, induce deficient protein synthesis resulting in cell death, but might also exert toxicity through inducing apoptosis. Target organs are intestinal mucosa, liver and kidneys. Poisoning will result in dehydration and electrolyte derangement, liver necrosis and possibly kidney damage. In established poisoning the mainstay of treatment is optimum symptomatic and supportive care. No specific treatment is available, but some pharmaceuticals, like silibinin, benzylpenicillin and acetylcysteine, might have a role in limiting the extent of hepatic damage. Orellanine is a nephrotoxic bipyridine N-oxide found in some Cortinarius species. Its mechanism of action is not fully understood, but it has been shown to inhibit protein synthesis and to generate free oxygen radicals. As early symptoms often are lacking or vague, poisoning may initially be overlooked or misinterpreted and the patients usually present with established renal damage. Supportive care is the only therapeutic option. Tricholoma equestre might contain a myotoxin and repeated ingestion may cause significant rhabdomyolysis. Ingestion of Amanita smithiana and A. proxima has been reported to result in kidney damage. Gyromitrin, a toxic compound that is converted to hydrazines in the stomach, occurs in some Gyromitra species. It is mainly neurotoxic, but may also induce moderate hepatic damage and haemolysis.

Treatment of amatoxin poisoning: 20-year retrospective analysis

BACKGROUND

Amatoxin poisoning is a medical emergency characterized by a long incubation time lag, gastrointestinal and hepatotoxic phases, coma, and death. This mushroom intoxication is ascribed to 35 amatoxin-containing species belonging to three genera: Amanita, Galerina, and Lepiota. The major amatoxins, the alpha-, beta-, and gamma-amanitins, are bicyclic octapeptide derivatives that damage the liver and kidney via irreversible binding to RNA polymerase II.

METHODS

The mycology and clinical syndrome of amatoxin poisoning are reviewed. Clinical data from 2108 hospitalized amatoxin poisoning exposures as reported in the medical literature from North America and Europe over the last 20 years were compiled. Preliminary medical care, supportive measures, specific treatments used singly or in combination, and liver transplantation were characterized. Specific treatments consisted of detoxication procedures (e.g., toxin removal from bile and urine, and extracorporeal purification) and administration of drugs. Chemotherapy included benzylpenicillin or other beta-lactam antibiotics, silymarin complex, thioctic acid, antioxidant drugs, hormones and steroids administered singly, or more usually, in combination. Supportive measures alone and 10 specific treatment regimens were analyzed relative to mortality.

RESULTS

Benzylpenicillin (Penicillin G) alone and in association was the mostfrequently utilized chemotherapy but showed little efficacy. No benefit was found for the use of thioctic acid or steroids. Chi-square statistical comparison of survivors and dead vs. treated individuals supported silybin, administered either as mono-chemotherapy or in drug combination and N-acetylcysteine as mono-chemotherapy as the most effective therapeutic modes. Future clinical research should focus on confirming the efficacy of silybin, N-acetylcysteine, and detoxication procedures.

The toxicology of Amanita phalloides

This paper examines the biology and medical consequences of ingesting the potential lethal poisonous mushroom, Amanita phalloides, the Death Cap. The organism is a fungus, its structure, distribution and toxic components are described. Symptoms of human poisoning by Am. phalloides are described, following the order of Homeopathic Repertories.

Toxins of Amanita phalloides

The most poisonous mushroom toxins are produced by Amanita phalloides (death cap). The occurrence and chemistry of three groups of toxins (amatoxins, phallotoxins and virotoxins) are summarized. The concentration and distribution of toxins in certain species are variable, with the young fruit body containing lower, and the well-developed fungus higher concentrations, but there is a high variability among specimens collected in the same region. Regarding phallotoxins, the volva (the ring) is the most poisonous. The most important biochemical effect of amatoxins is the inhibition of RNA polymerases (especially polymerase II). This interaction leads to a tight complex and the inhibition is of a non-competitive type. Non-mammalian polymerases show little sensitivity to amanitins. The amatoxins cause necrosis of the liver, also partly in the kidney, with the cellular changes causing the fragmentation and segregation of all nuclear components. Various groups of somatic cells of emanation resistance have been isolated, including from a mutant of Drosophila melanogaster. The phallotoxins stimulate the polymerization of G-actin and stabilize the F-actin filaments. The interaction of phallotoxins occurs via the small, 15-membered ring, on the left side of the spatial formula. The symptoms of human poisoning and the changes in toxin concentrations in different organs are summarized. Conventional therapy includes: (1) stabilization of patient's condition with the correction of hypoglycaemia and electrolytes; (2) decontamination; and (3) chemotherapy with different compounds. Finally, certain antagonists and protective compounds are reviewed, bearing in mind that today these have more of a theoretical than a practical role.