In vitro genotoxicity assays to evaluate the role of vitamin A on arsenic in human lymphocytes

Ground water contamination of arsenic in drinking water is a burning problem worldwide; especially in West Bengal (India) and Bangladesh. The main endeavor in this study was to assess the role of vitamin A (2.72 microM/7 ml culture), a naturally occurring antioxidant upon arsenic-induced genotoxicity; with respect to chromosomal aberrations (structural and numerical) and micronuclei. Whole blood cultures set for 72 h were exposed to test chemicals for a period of 24 h ahead of harvesting. Arsenic concentrations tested in the present study are 0.36, 0.72 and 1.4 microM/7 ml culture. Mitomycin C (MMC), the direct acting mutagen was used as positive control. Our data indicates that at concentrations tested, arsenic-induced increase in the mean frequencies of these genotoxic indices were diminished by vitamin A, indicating its protective role towards cells from arsenic exerted injury.

In vitro cytogenetic effects of Andrographis paniculata (kalmegh) on arsenic

In vitro effects of arsenic in human peripheral lymphocytes (HPL) at three different doses - 3.6x10(-4), 1.4 x 10(-3) and 0.72 x 10(-3) microM for 24h before harvesting on sister chromatid exchanges (SCE), Cell cycle proliferative index/replicative index (CCPI/RI), %M(1), %M(2) and %M(3), population doubling time (PDT) and average generation time (AGT) were examined. Andrographis paniculata (commonly referred to as 'kalmegh') has been used for centuries in traditional Indian and Chinese herbal medicine as a safe, natural folk remedy for assorted health concerns. In the present study, kalmegh (0.01 microg/7ml culture media) was used along with the highest dose of arsenic; the results showed that arsenic induced increase in these genotoxic endpoints were fairly diminished by kalmegh. In addition, mutagenic in vitro effect of ethyl methanesulphonate (EMS) was used as a positive control in this study. It is thus concluded from this study that Andrographis has a protective role in arsenic toxicity.

Genotoxic effects in human lymphocytes exposed to arsenic and vitamin A

Arsenic is a ubiquitous trace element and a well-established human carcinogen. In search for an 'antidote' to this global poison, this work was undertaken to study the probable beneficial effect of vitamin A upon arsenic induced genotoxicity. Peripheral blood lymphocyte culture was carried out to study the effects of arsenic at three different dose levels (0.5, 1 and 2 microg) for 24 h prior to harvesting. In addition, mutagenic in vitro effect of ethyl methanesulphonate was studied as a positive control. Genotoxic variables presented here are sister chromatid exchanges (SCE), cell cycle proliferative index/replicative index (CCPI/RI), average generation time (AGT) and population doubling time (PDT). Inevitably, arsenic treatment showed dose-dependent augmentation in the incidences of SCE and CCPI/RI together with AGT and PDT. However, vitamin A supplemented arsenic cultures demonstrated remarkable resurgence in the described genotoxic parameters. This data shows that vitamin A might be a useful interventional treatment in arsenic poisoning.

Arsenic induced free radical toxicity in brain of mice

The present study was designed to investigate the in vivo effects of oral administration of arsenic trioxide (As2O3; 0.5 and 1 mg/kg body weight/day for 45 days) on cerebral hemispheres and cerebellum in male mice, Mus musculus. Arsenic reduced the concentration of glutathione (GSH) in cerebral hemisphere and cerebellum at both the dose levels; while increased lipid peroxidation (LPO) in cerebral hemisphere and cerebellum regions. Further, the activities of antioxidant enzymes viz., superoxide dismutase and catalase also declined in these two regions with dose indicating oxidative stress. This effect is caused by the action of reactive oxygen species (ROS) induced by arsenic exposure.