Antiproliferactive activity of extracts from liquid culture of edible agaricomycetes (basidiomycota) fungal strains of human prostate tumor cells

Abstract

Fungi are eukaryotic organisms with absorbotrophic heterotrophic nutrition. They present growth with four phases: lag, exponential, stationary and senescent.The exponential phase presents a primary metabolism in charge of obtaining energy through nutrients and getting biomass. In the stationary phase they synthesize secondary metabolites (SM) that allow it to degrade the substrate and thus expand. Medicinal properties have been attributed for some of these SM. Studies on tumoral cells shown apoptosis induction, arrest of the cell cycle and impaired proliferation by effect of edible strains of the Agaricomycetes class. However, most of the studies were performed with the basidium and little is known about the effect of the extracellular medium (EM), where the SM are concentrated. In this study we aimed to evaluate the effect of the EM of different fungal strains on the viability of human prostate tumor cell. PC3 cells were cultured with EM (20%; 24h) from six different strains of fungi collected at exponential or stationary phase (days 7 or 21, respectively). We found that the EM of C. comatus, M. titans and G. lucidum, from day 21 significantly decreased (p <0.05) the viability of PC3 cells, evaluated by the MTS assay; whereas both EM (7 and 21) from C. cylindracea, impair viability of PC3 cells (p <0.05), with a significant decrease in the number of cells (p <0.05). These effects correlate with changes in cell-cycle where S phase grows at the expense of G1 phase. Nevertheless, no changes were observed in apoptosis levels, analyzed by flow cytometry with ANXAV-FITC / IP staining. These results indicate that EM of different strains of Agaricomycetes affect the viability of tumor cells, and this effect is not only dependent of the strain, but also on the growth phase.