Orellanine

A mycotoxin found in mushrooms of the family Cortinariaceae. Structurally, it is a bipyridine N-oxide, somewhat related to the herbicide diquat.

Orellanine first attracted attention in 1952, when a mass poisoning of 102 people in Konin, Poland, resulted in 11 deaths.

Orellanine poisoning is characterized by a prolonged latent period: initial symptoms typically appear 2–4–14 days after mushroom consumption. The latent period shortens with increasing amounts of mushrooms ingested. The first symptoms of orellanine poisoning resemble those of ordinary mild food poisoning (nausea, vomiting, abdominal pain, headaches, myalgia, etc.). These symptoms are followed by early stages of kidney failure (intense thirst, frequent urination, pain in and around the kidneys), and then reduced or complete absence of urination and other symptoms of renal failure. Without treatment, death may occur.

The LD50 of orellanine for mice ranges from 12 to 20 mg per kg of body weight; this is the dose that leads to death within two weeks.

There is no known antidote for orellanine poisoning. Treatment mainly consists of supportive therapy and hemodialysis if necessary. Complete recovery of kidney function occurs in only about 30% of poisoned individuals.