| Objective To evaluate the genotoxicity of DL-alanine from racemase.Methods Micronucleus test in mouse bone narrow was used to setnegative control group (pure water), positive control group (40 mg/kg cyclophosphamide) and three dose levels of DL-alanine from racemase(10 000,5 000,2 500 mg/kg), then the incidence of micronucleus in mouse sternal bone marrow cells in each groupwas observed.Chromosome aberration test of spermatogonia cells in mice was used toset negative control group (pure water), positive control group (40 mg/kg cyclophosphamide) and three dose levels of DL-alanine from racemase(10 000,5 000,2 500 mg/kg), then the chromosomal aberration types were observed and the aberration rate calculated in each group.The bacterial response mutation test wasused to set blank control group,solvent control group, positive control group and five dose levels of DL-alanine from racemase(50,158,500,1 580,5 000 μg/plate and 8,40,200,1 000,5 000 μg/plate), and the number of reversion mutants in each group was counted.Results The micronucleus test of mouse bone narrow and chromosome aberration test of spermatogonial cells in mice showed that each dose DL-alanine from racemase had no difference in chromosome aberration rate and micronucleus rate(P>0.05). The bacterial response mutation test indicated that none of the bacterial strains tested(TA97a, TA98, TA100, TA102, TA1535)showed an increase in revertants with or without S9 mixture at any dose.Conclusion DL-alanine from racemase shows no obvious genotoxicity. |
