title: In-vivo study of genotoxic and inflammatory effects of the organo-modified Montmorillonite Cloisite® 30B.
abstract: Because of the increasing use of clays and organoclays in industrial applications it is of importance to consider the toxicity of these materials. Recently it was reported that the commercially available Montmorillonite clay, Cloisite(®) 30B, which is surface-modified by organic quaternary ammonium compounds, was genotoxic in vitro. In the present study the in-vivo genotoxic and inflammatory potential of Cloisite(®) 30B was investigated as a follow-up of the in-vitro studies. Wistar rats were exposed to Cloisite(®) 30B twice 24h apart by oral gavage, at doses ranging from 250 to 1000 mg/kg body weight [indicate duration of treatment; Ed.]. There was no induction of DNA strand-breaks in colon, liver and kidney cells and there was no increase in inflammatory cytokine markers in blood-plasma samples. In order to verify the possible absorption of Cloisite(®) 30B from the gastrointestinal tract, inductively coupled plasma mass-spectrometry (ICP-MS) analysis was performed on samples of liver, kidney and faeces, with aluminium as a tracer element characteristic to clay. The results showed that aluminium could be detected in faeces, but not in the liver or kidneys. This indicated that there was no systemic exposure to clay particles from Cloisite(®) 30B. Detection and identification of free quaternary ammonium modifier in the highest dose of Cloisite(®) 30B was carried out by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). This analysis revealed a mixture of three quaternary ammonium analogues. The detected concentration of the organomodifier corresponded to an exposure of rats to about 5mg quaternary ammonium analogues/kg body weight.
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Toxicology & Risk Assessment, Mørkhøj Bygade 19, 2860 Søborg, Denmark. Electronic address: aksha@food.dtu.dk.
authors.forename: A K
authors.initials: AK
authors.lastname: Sharma
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Toxicology & Risk Assessment, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Mortensen
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Food Chemistry, Mørkhøj Bygade 26, 2860 Søborg, Denmark.
authors.forename: B
authors.initials: B
authors.lastname: Schmidt
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Food Chemistry, Mørkhøj Bygade 26, 2860 Søborg, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Frandsen
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Toxicology & Risk Assessment, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Hadrup
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Food Chemistry, Mørkhøj Bygade 26, 2860 Søborg, Denmark.
authors.forename: E H
authors.initials: EH
authors.lastname: Larsen
authors.affiliation: Technical University of Denmark, National Food Institute, Division of Toxicology & Risk Assessment, Mørkhøj Bygade 19, 2860 Søborg, Denmark.
authors.forename: M-L
authors.initials: ML
authors.lastname: Binderup
mesh_terms: D000538:Aluminum Silicates / Q000633:toxicity; D000818:Animals; D001546:Bentonite / Q000633:toxicity*; D015415:Biomarkers / Q000097:blood; D000077215:Clay; D003106:Colon / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020552:Comet Assay; D016207:Cytokines / Q000097:blood; D004249:DNA Damage / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology*; D007668:Kidney / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D000644:Quaternary Ammonium Compounds / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000538:Aluminum Silicates; D015415:Biomarkers; D016207:Cytokines; D000644:Quaternary Ammonium Compounds; D001546:Bentonite; D000077215:Clay
keywords: Absorption; Clay; Comet assay; Inflammation; Nanocomposite; Quaternary ammonium compound