N-Methylenephosphonic chitosan (NMPC) exerts cytotoxicity in fungal cells

ALBERTENGO L.; ZUÑIGA A.; RODRIGUEZ S.; CASALONGUÉ C.; MESAS F.; SILVEYRA M.X.; MENDIETA J.R.; DEBBAUDT A.; TERRILE M.C.

Buenos Aires

Encuentro; Reunión Conjunta de Sociedades de Biociencias; 2017

Varias Sociedades científicas

The aqueous solubility of chitosan depends on the degree of protonation of the NH2 group by acid treatment, which limits its versatility in biological fluids. However, N-methyl phosphonic chitosan (NMPC) is a chitosan derivative which hydrosolubility is improved due to the addition of aminoalkylphosphonic ligands. The aim of this study was to study whether NMPC has antifungal properties on the fungal pathogen Fusarium solani f sp eumartii (F. solani). Firstly, we analyzed the effect of NMPC on germination of F. solani spores. In vitro quantitative assays showed that NMPC exerted antifungal properties in a dose dependent manner, displaying an estimated IC50 value= 2.5 µg/ml. To investigate whether NMPC has a lethal effect on fungal spores, different experimental approaches were performed. F. solani spores were incubated in the presence of different concentrations of NMPC for 24h. Fungal viability was calculated counting the number of colony forming units (CFU). In addition, the effect of NMPC on cell plasma membrane validated citoxicity based on the uptake of the fluorogenic dye SYTOX Green. ROS production was in vivo measured by DAB staining in fungal spores upon 4 h of incubation with 2.5 µg/ml NMPC. Beside, tomato cell cultures were incubated with 2.5 and 5 µg/ml NMPC, and cell viability was tested with Evans blue. The results showed that at fungicida doses, NMPC is not toxic to plant cells. Simultaneous analysis of cell viability, cell permeabilization and activation of ROS generation explained integrative citotoxic properties mediated by NMPC on fungal cells.