title: Assessment of the mutagenic and genotoxic activity of cyanobacterial toxin beta-N-methyl-amino-L-alanine in Salmonella typhimurium.
abstract: A neurotoxin β-N-methylamino-L-alanine (L-BMAA) is a non-protein amino acid produced by most cyanobacteria ubiquitously present in aquatic and terrestrial environments. Due to its global presence in surface waters, a widespread human exposure is possible and therefore this toxin represents a health risk for humans and animals. L-BMAA has been linked to the development of a variety of neurodegenerative diseases. Its neurotoxic activity has been extensively studied, while nothing is known on its genotoxic properties. In the present study we evaluated for the first time L-BMAA mutagenic potential using Ames assay on several Salmonella typhimurium strains (TA97a, TA98, TA100, TA102 and TA1535). The results showed that the toxin (up to 0.9 mg/plate) did not induce mutations without or with S9 metabolic activation. Its genotoxic activity was further studied with the SOS/umuC assay on S. typhimurium TA1535/pSK1002 and the results showed that it was not cytotoxic nor genotoxic for bacteria. The present study represents the first evidence that L-BMAA is not mutagenic nor genotoxic for bacteria even at concentrations much higher than those typically found in the environment. However, as most of the cyanobacterial toxins are not bacterial mutagens it is very important to further elucidate its genotoxic activity in eukaryotic cells.
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia. Electronic address: matjaz.novak@nib.si.
authors.forename: Matjaž
authors.initials: M
authors.lastname: Novak
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia; Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia. Electronic address: klara.hercog@nib.si.
authors.forename: Klara
authors.initials: K
authors.lastname: Hercog
authors.affiliation: Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia. Electronic address: bojana.zegura@nib.si.
authors.forename: Bojana
authors.initials: B
authors.lastname: Žegura
mesh_terms: D065767:Activation, Metabolic; D000599:Amino Acids, Diamino / Q000378:metabolism / Q000633:toxicity*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000378:metabolism / Q000633:toxicity*; D000458:Cyanobacteria / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D004249:DNA Damage; D008387:Marine Toxins / Q000096:biosynthesis / Q000633:toxicity; D050296:Microbial Viability / Q000187:drug effects; D008862:Microsomes, Liver / Q000201:enzymology; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D009154:Mutation / Q000187:drug effects; D009498:Neurotoxins / Q000378:metabolism / Q000633:toxicity*; D009994:Osmolar Concentration; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects*; D014873:Water Pollutants / Q000378:metabolism / Q000633:toxicity
chemical_list: D000599:Amino Acids, Diamino; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D009153:Mutagens; D009498:Neurotoxins; D014873:Water Pollutants; C001824:beta-N-methylamino-L-alanine
keywords: Ames assay; Cyanobacterial toxin; Genotoxicity; Mutagenicity; SOS/umuC assay