Effects of pH and temperature on the genotoxicity of halogenated disinfection by-products in chlorinated water

Disinfection by-products (DBPs) are important environmental chemicals and the objective of this study was to assess the effects of pH, temperature and bromide concentration on the genotoxicity of DBPs in chlorinated water. Cells were exposed to humic acid samples and genotoxicity was assessed by chromosomal aberration assay using Chinese hamster lung (CHL) cells in vitro. A strong positive correlation between bromide concentration and the number of chromosomal aberrations formed was observed. Higher temperature values resulted in more chromosomal aberrations (14.6%) and a greater percentage of aberrant cells (24.6)% at pH 9 and, at higher bromide concentrations, more aberrations were formed at 25°C than 5°C for all pH values. There is some evidence that the number of aberrant cells is higher at 5°C at pH 7 than pH 5 or 9, however there does not appear to be any appreciable change in genotoxicity over the pH range tested.

Effects of pH and temperature on the genotoxicity of halogenated disinfection by-products in chlorinated water

Disinfection by-products (DBPs) are important environmental chemicals and the objective of this study was to assess the effects of pH, temperature and bromide concentration on the genotoxicity of DBPs in chlorinated water. Cells were exposed to humic acid samples and genotoxicity was assessed by chromosomal aberration assay using Chinese hamster lung (CHL) cells in vitro. A strong positive correlation between bromide concentration and the number of chromosomal aberrations formed was observed. Higher temperature values resulted in more chromosomal aberrations (14.6%) and a greater percentage of aberrant cells (24.6)% at pH 9 and, at higher bromide concentrations, more aberrations were formed at 25°C than 5°C for all pH values. There is some evidence that the number of aberrant cells is higher at 5°C at pH 7 than pH 5 or 9, however there does not appear to be any appreciable change in genotoxicity over the pH range tested.

Safety assessment of β-fructofuranosidase from Aspergillus brunneoviolaceus

β-Fructofuranosidase (β-D-fructofuranoside fructohydrolase; EC 3.2.1.26) is used in the production of fructo-oligosaccharides that are commonly used by the food industry as prebiotics for their purported health benefits. The β-fructofuranosidase discussed herein is obtained from a novel source organism that is a non-genetically modified strain of Aspergillus brunneoviolaceus, which phylogenetically belongs to the Aspergillus section Nigri. The safety of β-fructofuranosidase was evaluated in a series of toxicology studies as prescribed by Tier 1 toxicity testing by the European Food Safety Authority, including an evaluation of the mutagenicity and genotoxicity potential using the in vitro bacterial reverse mutation and mammalian chromosomal aberration assays, as well as systemic toxicity in a 90-day oral subchronic toxicity study in Sprague-Dawley rats. β-Fructofuranosidase was demonstrated to lack mutagenic or genotoxic potential based on the results of the in vitro assays due to absence of increased revertant colonies in the bacterial reverse mutation test and incidence of chromosome aberrations in the chromosomal aberration assay. Administration of β-fructofuranosidase by gavage at doses up to 1200 mg total organic solids (TOS)/kg body weight/day for 90 days did not elicit any systemic toxic effects in rats based on a lack of adverse effect in any study parameter, and therefore the no-observed-adverse-effect level of β-fructofuranosidase was concluded to be 1200 mg TOS/kg body weight/day, the highest dose tested. The results of the toxicology studies on β-fructofuranosidase from A. brunneoviolaceus demonstrate this species to be a safe and suitable source of enzymes for use by the food industry.

Analysis of Chromosomal Aberrations and Micronuclei in Type 2 Diabetes Mellitus Patients

Introduction: Type 2 diabetes mellitus is a metabolic disorder characterized by insulin resistance and disrupted insulin secretion. It is often linked to injuries, malfunction and failure of several organs in the long term. The elevated chromosomal disruptions and genetic complications in diabetic patients are due to the increased production of reactive oxygen species.Materials and Methods: The current study used chromosomal aberration assay and micronucleus assay to analyze the extent of abnormalities in the subjects.Results: The results showed increase in frequency of chromosomal aberrations in diabetic patients when compared to the control group (2.76±1.65 and 0.47±0.75 respectively). They also showed higher levels of micronuclei formation than the control participants (13.28±8.63 and 4.12±8.89 respectively).The correlation analysis indicated positive relationship between total aberrations and duration of diabetes.Conclusion: These results indicate that diabetes is associated with genomic instability and studies at a genetic level can be employed for early detection.

Sorption technique as a tool for reduction of genotoxicity

In the present study, the Allium cepa root chromosomal aberration assay was used to determine the genotoxic effects of copper and cadmium ions solutions before and after sorption processes. The sorption process was carried out using unmodified Dendrocalamus strictus charcoal powder, nitrilotriacetic acid (NTA)-modified D. strictus charcoal powder, and Saccharomyces cerevisiae. The frequency of total chromosomal aberrations was observed to be 24.30–45.13% for copper and 13.16–45.14% for cadmium at different concentrations (1–500 mg/l) before the sorption process. Both metal ions solutions resulted in significant reduction of chromosomal aberrations after all the modes of the sorption processes. However, the order of reduction of percentage chromosomal aberrations for copper and cadmium solutions was found to be 45.29–70.04% and 47.80–84.57%, respectively (NTA-modified D. strictus charcoal powder); >44.53–54.32% and 37.10–79.40%, respectively (unmodified D. strictus charcoal powder); >15.59–48.51% and 13.63–21.50%, respectively ( S. cerevisiae).