Aspergillus piperis a new source of toxic fungal metabolites

Autor: Jakšić, Daniela, Kocsubé, Sandor, Jelić, Dubravko, Šegvić Klarić, Maja
Přispěvatelé: Sviličić Petrić, Ines, Leboš Pavunc, Andreja, Šantić, Marina, Kifer, Domagoj
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Popis: Aspergillus piperis is one of the least investigated species of the section Nigri probably due to its rare occurrence in different food matrices and indoor environment. In our previously published study, a single indoor isolate of this species exerted the highest cytotoxic potential among the species from the section Nigri, including A. niger, A. welwitschiae, A. tubingensis and A. luchuensis [1]. Thus, we aimed to explore intraspecies differences in the cytotoxicity among five indoor isolates of A. piperis. Following incubation (7 days, 25 °C, dark) in liquid Czapek Dox broth, the mycelium and corresponding medium of an each isolate were extracted separately in the solvent composed of dichlormethane:ethyl acetate:methanol (1:2:3) supplemented with formic acid (1 % V/V), dried and dissolved in DMSO (100 mg/ml). The cytotoxicity of each isolate of A. piperis was obtained by MTT assay in human lung adenocarcionoma cells (A549) following the 24-h treatment of A549 cells with the extracted mycelium and the medium diluted (12.5–800 μg/ml in the cell medium). The most toxic were the strains MFBF AN11119B and MFBF AN12614 as the viability of A549 cells dropped by 90-100 % even at the lowest applied concentration (12.5 μg/ml) of the extracted mycelium and medium. The A. piperis strains were far less toxic as their IC50 ranged from 150 μg/ml to 510 μg/ml for the extracted mycelium and 600– 800 μg/ml for the extracted medium. To facilitate identification of the compound(s) responsible for exceptionally high cytotoxicity of the strain MFBF AN12614, mycelium extract was fractionated into 24 portions by liquid chromatography, dried and dissolved in DMSO (50- 100 mg/ml). The MTT assay performed on A549 cells selected the fractions 11 and 12 as the most cytotoxic. The cytotoxicity of these fractions was further explored by MTT assay in non-tumorigenic human bronchial epithelial cells (BEAS-2B cells) and the resulted IC50 were 1.4 μg/ml and 0.2 μg/ml for the fractions 11 and 12, respectively. The ongoing LC/MS analysis of the fractioned extract of A. piperis should reveal the identity of the compounds responsible for the observed cytotoxic effects.
Databáze: OpenAIRE