Toxicologically significant properties of fly agarics, and chemicotoxicological analysis in poisoning cases: a review

Every year the number of poisonings by Amanita (fly agaric), specifically red fly agaric (A. muscaria) and panther fly agaric (A. pantherina) increases. These species contain substances affecting the central nervous system, particularly muscimol, ibotenic acid, and muscarine. Ibotenic acid and muscimol are water-soluble isoxazole derivatives. They exert antagonistic effects on the central nervous system, stimulating and depressing it through inotropic glutamate receptors, which selectively bind N-methyl-D-aspartate, and gamma-aminobutyric acid receptors. The combined action of isoxazoles and other compounds of the fungus leads to the development of mycoatropin or pantherin syndromes. Muscimol is the most toxicologically significant, as it is capable of exerting a strong psychodysleptic effect, as well as causing disorder of consciousness up to the development of coma. Ibotenic acid is of equal importance in establishing the fact of fly agaric use, but in many cases it is almost completely converted to muscimol in the body. At this stage, active development of methods is underway to diagnose fly agaric poisoning: qualitative and quantitative determination of ibotenic acid derivatives in biological fluids (blood plasma and urine).

This review includes morphological features of red and panther fly agaric, their chemical composition and mechanisms of action of toxicologically significant compounds, types of qualitative and quantitative analysis, and symptoms of poisoning.

There are various methods to determine the etiology of poisoning, including polymerase chain reaction, micro- and macroscopy, but they do not allow determining the exact amount of toxicants correlating with the severity of poisoning. Precise physico-chemical methods such as chromatography and electrophoresis, which require multi-step sample preparation, are applicable for these purposes. Isolation from biological fluids or fruit bodies is accomplished by single-step or multi-step liquid-liquid or solid-phase extraction. The universal and most common extractant is 75% methanol. For qualitative analysis, thin layer chromatography with different solvent systems can be used. However, this analysis is non-specific and can be used in the preliminary phase of the study because the detectors used are group-wide. Gas and high-performance liquid chromatography are used for quantitative determination. These methods are highly precise; however, they require sample preparation. An alternative to chromatography is electrophoresis, an express method for the separation of muscimol and ibotenic acid.