Silibinin or Silly Putty for Mushroom Poisoning?
October 2, 2011, 3:08 pm
Shots, National Public Radio’s health blog, posted on Friday a hopelessly confused and misleading piece about role of silibinin in the treatment of Amanita mushroom poisoning.
Silibinin, an extract from the seed of the milk thistle plant (Silybum marianum), is often discussed as a possible treatment for poisoning from certain mushrooms such as Amanita phylloides, but has never been adequately studied (although there is an on-going drug-company-sponsored trial). It is commonly available over-the-counter as an oral preparation in health food stores, and sold under the name Legalon in Europe. Silibinin may act to inhibit sites on the hepatocyte membrane that facilitate uptake of amatoxin into the cell. It is also an antioxidant.
The Shots blog post reports that with all the heavy rain on the east coast this summer, an abundance of Amanita mushrooms has sprouted. Georgetown University Hospital has admitted four patients from Virginia and Maryland over the last month with toxic mushroom poisoning. These patients were treated with intravenous silibinin on an experimental basis. According to the post, two patients recovered and two are in fair condition.
However, the report states that the first two patients developed severe nausea, vomiting, and diarrhea within hours of eating the mushrooms. These early-onset gastrointestinal effects are not consistent with Amanita ingestion. It is always possible, of course, that a mixture of mushrooms was consumed, with some non-Amanita species causing the rapid GI effects. But how did the Georgetown physicians know specifically that Amanita was also ingested?
It may be that the ongoing multicenter trial will demonstrate a benefit of silibinin in this setting. At the present, however, there is as much scientific evidence for using silibinin to treat Amanita toxicity as there is for using Silly Putty.
jj Says:
a couple of clarifications…Legalon is a milk thistle extract containing many different silymarin isomers. The product used for mushroom poisoning is one of the isomers called silibinin which is isolated and purified. IV silibinin has been used in thousands of patients in the past 40 years and the amatoxin poisoning survival rate has fallen from 80% prior to its introduciton to more than 90% after its introduction.
October 3rd, 2011
Marilyn Shaw Says:
I agree that the NPR piece had serious problems. I have notified them to that extent. However, more clarification than that stated here is still needed.
“IV silibinin has been used in thousands of patients in the past 40 years and the amatoxin poisoning survival rate has fallen from 80% prior to its introduciton to more than 90% after its introduction.”
Injectable silibinin has been used for several years in Europe. However, according to Thomas Zilker, Munich, Germany, there have not been enough cases to draw any meaningful conclusions.
In over the last 100 years in the U.S. the mortality rate from mushroom poisonings has averaged fewer than 1.5 per year.
Mortality in untreated amatoxin cases has been approximately 50%. This can be reduced with aggressive, timely supportive care to about 10%.
The chief investigator of the Legalon SIL trials in the U.S. has stated that the most important treatment is aggressive fluid replacement, since once the kidneys are affected not much can be done (personal communication).
It is not true, as stated in some other recent blogs, that oral use of milk thistle is effective in these cases.
October 4th, 2011
Leon Says:
jj:
Thanks for the clarification about intravenous Legalon SIL. However, if the survival rate of amatoxin mushroom poisoning has gone from 80% to 90% over the last 40 years I’m not sure what to make of it. Obviously, supportive care, critical care, and treatment of acute hepatic failure has improved in all sorts of ways over that time. I’m am not aware of any evidence indicating that silibinin improves clinical outcome. I do look forward to the results of the ongoing multi-center trial, but since it is open label and does not appear to have a control group, I doubt we’ll get any real answers.
Marilyn:
Thank you for the further clarification. I quite agree with all you comments.
October 4th, 2011