Decoding the killer mushroom Amanita fuligineoides toxicity: from toxin profiling to organ injury mapping

Mushroom poisoning has been a long-standing public health emergency, causing the highest mortality rate and highest number of deaths among food poisonings in China. Lethal Amanita species account for 90 % of all fatal mushroom poisonings. Amanita fuligineoides is among the major poisonous mushrooms responsible for poisoning and death in China. However, its toxicity and poisoning mechanism remain largely unknown. This study comprehensively investigated the toxicity and toxicological effects by integrating toxin profiling, dose-time effects, biochemical indicators in serum, and organ injury mapping in mice. High-performance liquid chromatography (HPLC) identified four cyclic peptide toxins in A. fuligineoides crude extract (AFCE). Animal experiments showed that gavage and intraperitoneal injection of AFCE caused the poisoning symptoms and acute liver and kidney damages, but the poisoning caused by the latter was far more severe than the former. The dose-time effect experiment revealed dose-dependent liver and kidney damage, characterized by increased alanine transaminase (ALT) and aspartate aminotransferase (AST) activities, as well as elevated urea nitrogen and creatinine levels. A unique "low-dosage - delayed injury" pattern was observed in mice, with biochemical markers peaking as early as 12–24 h post-exposure, preceding clinical symptoms. High-dose AFCE triggered death within 8 h. Pathological examinations confirmed hepatotoxic and nephrotoxic effects such as steatosis, necrosis, and mitochondrial collapse. Additionally, AFCE impaired functions of both the central nervous system and immune system. Together, this study reveals the poisoning development process and toxicology of A. fuligineoides and provides practical guidance for the prevention and treatment of Amanita mushroom poisonings.