Amaranth lectin presents potential antitumor properties

The possibility of reducing the risk of cancer is one of the most important challenges facing scientists. In this work we demonstrate that the amaranth lectin presents potential antitumor activity and we propose a mechanism of action. Our results indicate that the albumins and a hydrophobic fraction (MPI-h) from the Amaranthus mantegazzianus protein isolate (MPI) are capable of inhibiting UMR106 rat osteosarcoma-derived cell proliferation. Further fractionation of the hydrophobic fraction and LC-MS/MS analyses of the tryptic peptides showed the presence of lectin fragments in one active fraction. When a partially purified A. mantegazzianus lectin and the commercial Amaranthus caudatus lectin were tested as cell-proliferation inhibitors, both lectins showed high activity with an IC50 = 0.1 mg/mL and 0.08 mg/mL respectively; similar to MPI-h activity. Lectins would exert a cytotoxic effect followed by cell apoptosis, in addition to inhibiting cell adhesion.