Assessment of genotoxicity of inorganic mercury in rats in vivo using both chromosomal aberration and comet assays.

The major objective of the present investigation was to assess the genotoxic effects of mercuric chloride (HgCl2), an inorganic mercury (Hg), in rats (Rattus norvegicus) using two different genetic endpoints, namely, chromosomal aberration (CA) and comet assays following both short-term (acute) and long-term (chronic) exposures. The study showed that the acute exposures to HgCl2 at 2 and 5 mg/kg body weight (b.w.) induced nonsignificant effects. HgCl2 at 10 and 12 mg/kg b.w. was significantly toxic and is exhibited by the induction of different types of CAs like chromatid breaks, chromosomal breaks, clumps and damaged cells and types of comets. HgCl2 at 15 mg/kg b.w. was found to be highly toxic, as mitostatic condition of cells were observed in CA assay. Chronic exposure to the lowest dose (2 mg/kg b.w.) of HgCl2 for 15 consecutive days produced a significant genotoxicity. Although Hg was found to induce both DNA strand breakage and chromosomal breaks in a dose-dependent manner, the results of the present investigation showed that the combination of comet and CA assays provided a better choice for assessing the genotoxicity of inorganicHg.

Search for a diagnostic/prognostic biomarker for the brain cancer glioblastoma multiforme by 2D-DIGE-MS technique.

The prognosis of patients with glioblastoma multiforme, the most malignant adult glial brain tumor, remains poor in spite of advances in treatment procedures, including surgical resection, irradiation, and chemotherapy. Genetic heterogeneity of glioblastoma warrants extensive studies to gain a thorough understanding of the biology of this tumor. While there have been several studies of global transcript profiling of glioma with the identification of gene signatures for diagnosis and disease management, translation into clinics is yet to happen. In the present study, we report a novel proteomic approach by using two-dimensional difference gel electrophoresis followed by spot picking and analysis of proteins/peptides by Mass spectrometry. We report at least ten different novel proteins/peptides as identified by this technique which are differentially expressed in this cancer and could be of further importance for diagnostic, therapeutic, and prognostic approaches.

Use of black tea in modulating clastogenic effects of arsenic in mice in vivo.

The concentration of arsenic in drinking water has far exceeded the permissible limit of 0.001 mg/L and has reached epidemic proportions, with a maximum of 3.7 mg/L in several districts of West Bengal and in the adjoining Bangladesh. Because inorganic arsenic is a documented human carcinogen, arsenic in drinking water may cause 200,000-270,000 deaths per year from cancer in India alone. Tea has a protective effect against the clastogenicity of arsenic. We investigated whether tea extracts could protect against the damage caused by arsenic in vivo. Our experiments were carried out with black tea in mice with the end points of incidence of chromosomal aberrations and damaged cells. Analysis of variance of chromosomal aberrations showed a significant difference in the toxic effects of arsenic, which were reduced by tea infusion. The frequency of chromosomal aberrations was close to the corresponding effects of tea alone. Continued dietary administration of black tea infusion protects against the chromosome-damaging effects of sodium arsenite at a statistically significant level. The degree of protection increases with duration of tea consumption, which may be attributed to the antioxidant and scavenging properties of tea infusion.