Isolation, purification, LC-MS/MS characterization and reactive oxygen species induced by fumonisin B1 in VERO cells

Fumonisins are mycotoxins produced by Fusarium verticillioides that commonly contaminate maize and maize products. The present work shows the results of a comparative study of three different fermentation's techniques (solid and liquid medium of corn and a solid agarized medium) for the production of fumonisins B(1), B(2) and B(3) with strains of F. verticillioides. The solid medium of corn was the most effective in the production of fumonisins, being Fumonisin B(1) the one produced with higher concentration, so the extract obtained by solid fermentation process was used for FB(1) purification. Fumonisins characterization and quantification were performed with reversed-phase high-performance liquid chromatography with electrospray ionization triple quadrupole tandem mass spectrometry. The role of production of reactive oxygen species (ROS) in Fumonisin B(1) mediated toxicology has not been fully addresses in studies exploring FB(1) toxicity. It is evaluated the level of ROS production in kidney cell line (VERO) exposed to 1, 5 and 10 μM of FB(1) for 0.5-100 min. The ROS level was detected using a fluorescence probe, 2',7'-dichlorofluorescein diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS. Significant increase of ROS products was observed in VERO cells at 10 μM dose. These results indicate that ROS production by FB(1) on renal cells is a mechanism of fumonisin mediated toxicity.