Toxic Substances from Mushrooms

Abstract

Toxic substances from certain species of various genera of the poisonous mushrooms have been isolated, and their chemical structures have been elucidated. Cyclic octapeptides(amatoxins) which derived from several species of Amanita and Galerina mushrooms seem to be the most toxic fungal toxin presently known. These compounds are very potent nonspecific cytotoxin, producing damages to various organs, notably the liver and the kidney. To make thing even worse, clinician who takes care of the patients with this type of poisoning may be misleading because the patients seem to recover after the initial phase of gastrointestinal disorders; however, serious effects such as acute fatal hepatitis usually occur after four to five days of ingestion. Most patients died unless intensive treatments had been early introduced. Muscimol and psilocybin are two mushroom toxins that primarily affect the central nervous system. Fungi containing these compounds have been used as hallucinogens, and the epidemic of the abuse of these mushrooms have been reported in some countries. Psilocybin also stimulates the sympathetic nervous system leading to mydriasis and tachycardia. Mushroom toxins that act principally on the autonomic nervous system include 1-aminocyclopropanol and muscarine. 1-Aminocyclopropanol possesses a disulfiram-like action, while muscarine stimulates the parasympathetic nervous system. Little is known about the chemical nature and mechanism of action of the gastrointestinal irritants. This group of toxins produces varying degrees of abdominal disturbances, depending on the species of fungi, individual sensitivity, and age of the consumers. Although the incidence of mushroom poisoning in Thailand is relatively low, knowledge of the nature of each type of fungal intoxication may be helpful in treatment of the patients, particularly in amatoxin poisoning.