Clastogenic and mutagenic effects of bisphenol A: an endocrine disruptor.

Bisphenol A (BPA) is a well-known endocrine disruptor (ED) which represents a major toxicological and public health concern due to its widespread exposure to humans. BPA has been reported to induce DNA adduct and aneuploidy in rodents. Recent studies in humans depicted its association with recurrent miscarriages and male infertility due to sperm DNA damage indicating that BPA might have genotoxic activity. Hence, the present study was designed to determine genotoxic and mutagenic effects of BPA using in-vivo and in-vitro assays. The adult male and female rats were orally administered with various doses of BPA (2.4 µg, 10 µg, 5mg and 50mg/kgbw) once a day for six consecutive days. Animals were sacrificed, bone marrow and blood samples were collected and subjected to series of genotoxicity assay such as micronucleus, chromosome aberration and single cell gel electrophoresis (SCGE) assay respectively. Mutagenicity was determined using tester strains of Salmonella typhimurium (TA 98, TA 100 and TA 102) in the presence and absence of metabolically active microsomal fractions (S9). Further, we estimated the levels of 8-hydroxydeoxyguanosine, lipid per-oxidation and glutathione activity to decipher the potential genotoxic mechanism of BPA. We observed that BPA exposure caused a significant increase in the frequency of micronucleus (MN) in polychromatic erythrocytes (PCEs), structural chromosome aberrations in bone marrow cells and DNA damage in blood lymphocytes. These effects were observed at various doses tested except 2.4 µg compared to vehicle control. We did not observe the mutagenic response in any of the tester strains tested at different concentrations of BPA. We found an increase in the level of 8-hydroxydeoxyguanosine in the plasma and increase in lipid per-oxidation and decrease in glutathione activity in liver of rats respectively which were exposed to BPA. In conclusion, the data obtained clearly documents that BPA is not mutagenic but exhibit genotoxic activity and oxidative stress could be one of the mechanisms leading to genetic toxicity.

Polyethylene sebacate: genotoxicity, mutagenicity evaluation and application in periodontal drug delivery system.

The objective of the present study is to evaluate Polyethylene sebacate (PES) for its toxicity profile including oral toxicity, genotoxicity and mutagenicity. PES was synthesised, and characterised by gel permeation chromatography, FTIR, (1)H-NMR, differential scanning calorimetry and X-ray diffraction. Oral toxicity studies revealed PES to be nontoxic up to 3000 mg/kg body weight with no significant changes in serum biochemistry. The standard battery of genotoxicity tests including micronucleus test, chromosomal aberration and comet assay revealed PES as nongenotoxic. Mutagenicity of PES was evaluated using the Ames microplate format mutagenicity assay sample kit using TA98 and TA100 strains of Salmonella typhimurium, both in presence and absence of Aroclor 1254 induced rat liver S9. Ames assay confirmed PES to be nonmutagenic. Periodontal implants of PES of varying roxithromycin/PES ratios and different diameter were prepared. A decrease in in vitro drug release was seen with increase in diameter of the implants. Release rates, however, increased with increase in PES concentration, and were attributed to decreased crystallinity of roxithromycin, confirmed by the DSC thermographs and XRD spectra. Roxithromycin release from the implants followed Higuchi kinetics and exhibited controlled release. The results suggest PES as a safe polymer for biomedical and pharmaceutical applications.