In vitro and in vivo genotoxicity studies on monosodium L-glutamate monohydrate.

In response to the lack of authenticated mutagenicity/genotoxicity studies on MSG monohydrate, a series of genotoxicity studies conducted under GLP and according to globally accepted test guidelines (e.g., OECD) was performed. A bacterial reverse mutation test using Salmonella typhimurium (TA100, TA1535, TA98 and TA1537) and Escherichia coli (WP2 uvrA) at concentrations up to 5000 µg/plate, an in vitro chromosomal aberration test in CHL/IU cells at concentrations up to 10 mmol/L (1.9 mg/mL), a mouse lymphoma tk assay at concentrations up to 10 mmol/L (1.9 mg/mL), an in vitro micronucleus test in human peripheral blood lymphocytes at concentrations up to 10 mmol/L (1871 µg/mL), and an in vivo micronucleus test in bone marrow of rats that were gavaged with up to 2000 mg/kg bw were investigated. MSG monohydrate did not cause mutagenicity in any bacterial strain, did not induce chromosomal aberrations in CHL/IU cells or gene mutation in mouse lymphoma cells, was not clastogenic or aneugenic to human lymphocytes, and did not induce micronuclei in erythrocytes of rats when compared with vehicle controls. These results show that MSG is not mutagenic or genotoxic under the study conditions.