Evaluation of cytotoxic effect against tumour cells of the acidic polysaccharides of the fungus nothophellinus andinopatagonicus

Abstract

Fungal polysaccharides possess an important bioactive potential, including antioxidant and anticarcinogenic activity. The aim of this work was to determine the antioxidant activity and cytotoxicity against tumour and non-tumour cell lines acidic polysaccharides (NAAPs) of the fungus Nothophellinus andinopatagonicus. The effect of NAAPs on tumour cells lines was evaluated by MTT assay and flow cytometry. The analyses determined that glucose was the most abundant monomer and IR spectrum showed the typical peaks of β-glucans in the NAAPs. The cell viability assays revealed significant activity of NAAPs against HL-60, HCT-116 and MCF-7 tumour cell lines (IC50 = 767,16 µg mL-1 , 1256 µg mL-1 and 4241,7 µg mL-1 , respectively); but a much lower cytotoxicity against the non-tumour cell line HGF-1 (outside the range of the highest concentration tested (>10 mg mL-1 )). NAAPs affected the cell cycle of HL-60 tumour cells, increasing the percentage of cells in the sub G1 phase and reducing it in the S/G2/M phases. Moreover, low concentrations of NAAPs also showed an effective cytotoxic activity against tumour cell lines while the non-tumour cell line was unaffected, maintaining a viability close to 100%. The antioxidant activity of the highest NAAPs concentration tested was 6.24% and 4.63%, for DPPH and ABTS method, respectively.