Potential antidote for death cap mushrooms poisoning found

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Holger Krisp, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons
Holger Krisp, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons

Death cap mushrooms cause over 90% of mushroom-related deaths worldwide and now Australian and international scientists think they may have found an antidote to their deadly poison.  The main toxin produced by the death cap mushrooms is called α-amanitin and the researchers identified a key protein, STT3B, which is required for α-amanitin, to have its toxic effect. Once they identified this protein the researchers then looked for drugs that might block it and they found one, called  indocyanine green which is already approved by the US Food and Drug Administration.  When they tested this drug on human cells and mice exposed to the toxin it acted as an antidote, blocking its toxic effects and helping the animals survive.  The authors say more work is needed to assess its safety for use in humans. 

Media release

From: Springer Nature

2.  Pharmacology: A potential antidote for death cap mushroom poisoning

The US Food and Drug Administration approved diagnostic substance indocyanine green reduces the toxicity of α-amanitin, a toxin produced by the world’s most poisonous mushroom — the death cap — in human cell lines and mice, according to a Nature Communications paper. The findings suggest that this substance could present a potential antidote treatment for death cap poisoning in humans, which are responsible for over 90% of mushroom-related deaths worldwide.

Mushroom poisoning is the main cause of mortality in food poisoning incidents worldwide. In China alone, almost 40,000 illnesses and 788 deaths were reported between 2010–2020. α-amanitin is the main toxin produced by the death cap mushroom and causes high rates of irreparable liver or kidney damage and mortality following consumption. Despite its lethal effects, the exact molecular mechanisms of α-amanitin’s toxicity remain unclear, and no specific antidote is currently available. 

Qiaoping Wang and colleagues used genome-wide CRISPR screening to identify molecular targets for α-amanitin and found that the protein STT3B, a key component of the N-glycan biosynthesis pathway involved in protein folding and trafficking in a large number of biological recognition events, is required for α-amanitin toxicity. Using a virtual drug screening, they identified indocyanine green as an inhibitor of STT3B that may prevent liver toxicity. Indocyanine green was also found to increase the probability of survival of human cell lines and mice exposed to α-amanitin.

Further research is needed to understand the exact mechanisms indocyanine green uses to inhibit α-amanitin and assess its safety for use in humans. The authors also suggest that the method of combining genome-wide CRISPR screening with virtual drug screening could help to quickly identify new antidotes for other medically relevant human poisons.

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conference:
Nature Communications
Research:Paper
Organisation/s: The University of Sydney, Garvan Institute of Medical Research, Sun Yat-sen University, China
Funder: This work was funded by the National Natural Science Foundation of China (31970934), Natural Science of Foundation of Guangdong province, China (2018B030306002), Science and Technology Innovation Committee of Shenzhen, China (201908073000449), and the Fundamental Research Funds for the Central Universities to Q.P.W. This work was also supported by grants from the National Natural Science Foundation of China (82122069, 82073869); Guangdong Basic and Applied Basic Research Foundation (2021B1515020004, 2019A050510019); Guangdong Provincial Key Laboratory of Construction Foundation (2017B030314030, 2020B1212060034); Guangzhou Science and Technology Planning Program (202002020051).
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