AbstractThe carcinogenicity and mutagenicity of chemicals may be modulated by other chemicals, including those prepared by organic synthesis. Considering the several drawbacks of synthetic compounds vis-a-vis the human organism, the lignin biomass component was examined for this purpose. The binding affinity of lignin samples prepared by chemical and biological modification of lignin products derived from chemical wood treatment towards for N-nitrosodiethylamine (NDA) was examined. The protective role of the lignin samples against carcinogenesis was tested on a well-known model carcinogen, N-methyl-N´-nitro-N-nitrosoguanidine (MNNG). The observed ability of a series of lignin preparations to reduce alkylation damage of deoxyribonucleic acid (DNA) on hamster cells in vitro could be explained by their affinity to bind N-nitrosoamines. The results indicate that lignin has potential to protect living organisms against damaging effects of different genotoxicants.