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.