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L Krizková

Publications and source records attributed to L Krizková.

21 records · Page 2Linked to original sources

Antimutagenicity of lignin in vitro.

The inhibitory activity of lignin against nitrosoguanidine (MNNG)- and acridine orange (AO)- induced mutagenesis was examined using two microbial systems: green unicellular flagellate Euglena gracilis and Salmonella typhimurium TA100 and TA97. To verify the hypothesis that the above mentioned mutagens may generate some oxidant species and subsequently free radicals, or they may interact with lignin, two physico-chemical measurements were performed. Lignin at a tested concentration (100 micrograms/ml) decreases Euglena-bleaching activity of MNNG by 67.7% and AO by 99.7%. Percentage of MNNG-induced revertants of S. typhimurium was also decreased substantially by lignin. We conclude that our results indicate the possible mechanisms behind the antimutagenic/anticarcinogenic effects of lignin: namely, scavening of reactive oxygen species produced by MNNG and binding of AO itself.

Acridine Orange↗

Lignin reduces ofloxacin-induced mutagenicity in Euglena assay.

The possible protective effect of sulphur-free beech lignin polymer on the mutagenicity of ofloxacin in Euglena gracilis was studied. The generation of oxygen species by ofloxacin and their possible interaction with lignin was verified by physico-chemical measurements. The UV absorbance spectra of ofloxacin with and without lignin showed no interaction between these two compounds. The production of superoxide anion radical (O2-) by ofloxacin was significantly reduced in the presence of lignin (AIR = 0.57 +/- 0.03, p < 0.01). Lignin, at concentrations of 125 and 250 micrograms/ml decreased the E. gracilis bleaching activity of ofloxacin to 39.9% and 2.8%, respectively. A lignin concentration of 500 micrograms/ml eliminated the bleaching activity of ofloxacin very efficiently. Our results are consistent with the concept that lignin biopolymer has the capability of reducing genotoxic activity by scavenging reactive oxygen species.

Animals↗