Toxicokinetics of Α- and Β-Amanitin in Mice Following Single and Combined Administrations: Simulating in Vivo Amatoxins Processes in Clinical Cases.

alpha-Amanitin and beta-amanitin, two of the most toxic amatoxin compounds, typically coexist in the majority of Amanita mushrooms. The aim of this study was to use a newly developed ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method to determine the toxicokinetics and tissue distribution of alpha- and beta-amanitin following single or combined oral (po) administration in mice. alpha-Amanitin and beta-amanitin administered at 2 or 10 mg/kg doses showed similar toxicokinetic profiles, except for peak concentration (Cmax). The elimination half-life (t(1/2)) values of alpha-amanitin and beta-amanitin in mice were 2.4-2.8 h and 2.5-2.7 h, respectively. Both alpha- and beta-amanitin were rapidly absorbed into the body, with times to reach peak concentration (Tmax) between 1.0 and 1.5 h. Following single oral administration at 10 mg/kg, the Cmax was significantly lower for alpha-amanitin (91.1 mu g/L) than for beta-amanitin (143.1 mu g/L) (p < 0.05). The toxicokinetic parameters of alpha-amanitin, such as t(1/2), mean residence time (MRT), and volume of distribution (Vz/F) and of beta-amanitin, such as Vz/F, were significantly different (p < 0.05) when combined administration was compared to single administration. Tissues collected at 24 h after po administration revealed decreasing tissue distributions for alpha- and beta-amanitin of intestine > stomach > kidney > lung > spleen > liver > heart. The substantial distribution of toxins in the kidney corresponds to the known target organs of amatoxin poisoning. The content in the stomach, liver, and kidney was significantly higher for of beta-amanitin than for alpha-amanitin at 24 h following oral administration of a 10 mg/kg dose. No significant difference was detected in the tissue distribution of either amatoxin following single or combined administration. After po administration, both amatoxins were primarily excreted through the feces. Our data suggest the possibility of differences in the toxicokinetics in patients poisoned by mushrooms containing both alpha- and beta-amanitin than containing a single amatoxin. Continuous monitoring of toxin concentrations in patients' blood and urine samples is necessary in clinical practice.