Antimutagenic activity of proteins (lectins) fraction from herb of Nettle

Plant lectins are non-enzymic and non-immune origin proteins that specifically recognize and bind to various sugar structures and possess the activity to agglutinate cells and/or precipitate polysaccharides and glycoconjugates. The emerging evidences showed that plant lectins contribute not only to tumour cell recognition but also to cell adhesion and localization, to signal transduction, to mitogenic cytotoxicity and apoptosis. The aim of the study was to evaluation the antimutagenicity and the cytotoxicity of a lectin-enriched fraction from Nettle herb. The antimutagenicity was studied in a bacterial reverse mutation assay (Ames test), both in the absence and presence of an exogenous metabolic activator S9 (the liver postmitochondrial supernatant of rats treated with the mixture phenobarbital/β-naphthoflavone to induce the hepatic microsomal enzymes). Cytotoxicity was determined by the tetrazolium dye (MTT) colorimetric assay in HepG2 human hepatoblastoma cell line. The fraction did not display any significant reduction in the cell viability of HepG2 cells. Conversely, it inhibited the antimutagenic effect of the mutagen 2AA (2-aminoanthracene) in all strains tested.