Fumonisin B1-induced toxicity and oxidative damage in U-118MG glioblastoma cells.

The mycotoxin fumonisin B1 (FB1) is produced by Fusarium verticillioides, which commonly infects corn and other agricultural products. Fusarium species are also a frequent finding in moisture-damaged buildings, causing possible human exposure to FB1. FB1 is neurotoxic and carcinogenic in a number of animal species. In this study, we have investigated the effects of FB1 on human U-118MG glioblastoma cells. The production of reactive oxygen species (ROS), lipid peroxidation, intracellular reduced glutathione (GSH) levels, cell viability, caspase-3-like protease activity and DNA fragmentation were studied in cells exposed to 0.01-100 microM FB1 for 0.5-144 h. FB1 increased lipid peroxidation and the production of ROS in U-118MG cells, showing significant effects after culture times from 48 to 144 h at dose levels of 10 or 100 microM FB1. These effects were accompanied by changes in the GSH levels and cell viability, which decreased significantly after incubating the cells for 48-144 h with the toxin. Signs of apoptosis were indicated by increased caspase-3-like protease activity and internucleosomal DNA fragmentation. Thus, oxidative stress and apoptosis may be involved in the neurotoxicity induced by FB1.