Antimutagenicity of lignin in vitro

The inhibitory activity of lignin against nitro-soguanidine (MNNG)- and acr idine orange (AO)- induced mutagenesis was examined using two microbial sys tems: green unicellular flagellate Euglena gracilis and Salmonella typhimur ium TA100 and TA97. To verify the hypothesis that the above mentioned mutag ens may generate some oxidant species and subsequently free radicals or the y may interact with lignin. two physico-chemical measurements were performe d. Lignin at a tested concentration (100 mu g/ml) decreases Euglena-blenchi ng activity of MNNG by 67.7% and AO by 99.7%. Percentage of MNNG-induced re vertants of S. typhimurium was also decreased substantially by lignin. We c onclude that our results indicate the possible mechanisms behind the antimu tage-nic/anticarcinogenic effects of lignin, namely, scavening of reactive oxygen species produced by MNNG and binding of AO itself.