[Evaluation of Psilocybe cubensis (Agaricales, Basidiomycota) toxicity over Artemia franciscana (Crustacea, Anostraca)]

Mushrooms to live or die: toxicity of some Basidiomycota using Artemia franciscana

Consumption of wild mushrooms has increased in recent years; however, not all of them are edible and there is no precise information on those that may cause poisoning. Therefore, studies to obtain data about their toxicity are needed. For this purpose, we used the brine shrimp Artemia franciscana, a crustacean employed in toxicity tests and with wide application in the toxin detection, including mycotoxins. Mushrooms were collected in the state of Jalisco, Mexico, with which aqueous extracts were prepared. Dilutions of the stock solution of each extract were made to final concentrations of 50, 100, 250, 500, and 1000 µg/mL. Potassium dichromate (PD) was used as positive control and artificial seawater as negative control. The median lethal dose (LD50) of extracts on nauplii of A. franciscana was calculated. The aqueous extracts obtained from Amanita amerivirosa, A. muscaria, Chlorophyllum molybdites, and Leucopaxillus amarus showed a LD50 < 70 µg/mL, similar to PD (LD50 = 37 µg/mL). This is the first indication of the probable toxicity of Leucopaxillus amarus in humans. Cantharellus cibarius and Scleroderma texense caused the lower toxicity to the nauplii. The brine shrimp bioassay was effective in evaluating the toxicity of Basidiomycota. Scleroderma texense has been reported to be toxic, but it was not for this crustacean nauplii, and probably not to humans either, as recent literature has reported.

[Evaluation of the toxicity of Basidiomycota fungi on the hatching of Artemia franciscana cysts]

BACKGROUND

The consumption of wild mushrooms has increased in recent years. However, not all mushrooms are edible and some of them may cause poisoning. Therefore, their toxicity needs to be studied. Artemia franciscana is a crustacean used in toxicity tests including toxins of fungi.

AIMS

To determine the percentage of inhibition and mortality produced by extracts of several basidiomycetes on the hatching of A. franciscana cysts.

METHODS

Aqueous extracts were prepared from 15 species of mushrooms collected from Jalisco state, Mexico. Different concentrations of the extracts were assayed in order to test their toxicity. Potassium dichromate and artificial seawater were the positive and negative controls, respectively. The percentages of hatching and mortality of the cysts were evaluated.

RESULTS

Inhibition of hatching greater than 80% in all the concentrations tested was found in 13 of the 15 species studied, in contrast to the positive control, which inhibited cyst hatching less than 50% in all cases. The highest percentage of mortality in the cysts was caused by the aqueous extracts of Amanita virosa, Leucopaxillus amarus, and Tylopilus violatinctus, and the lowest by Macrolepiota mastoidea.

CONCLUSIONS

The brine shrimp bioassay appeared to be useful in the evaluation of the toxicity of several basidiomycetes, with the exception of Scleroderma texense, a mushroom considered poisonous, which showed no toxicity over A. franciscana.