Cytogenetic evaluation of cadmium chloride on Channa punctatus.

The aim of present study was to evaluate the genotoxic effect of heavy metal in Channa punctatus through the micronucleus test, chromosomal aberrations and sister chromatid exchange. The fish were kept separately in 0.5, 1.0, 2.0 and 5.0 ppm cadmium chloride for 3 days. For micronucleus test blood was collected from caudal vein and smeared on clean slides fixed in methanol and stained with 2% Giemsa. Mean frequency of micronuclei observed was 0.10, 0.15, 0.24, 0.34 and 0.39 in control, 0.5, 1.0, 2.0 and 5.0 ppm CdCl2 respectively. In vivo chromosome preparation from kidney tissues was carried out. The mean frequency of cells with aberrations observed was 0.13, 0.20, 0.34, 0.60 and 0.95 in control, 0.5, 1.0, 2.0 and 5.0 ppm CdCl2 respectively. Likewise the mean frequency of SCE observed was 0.05, 0.16, 0.36, 0.44 and 0.52 in control, 0.5, 1.0, 2.0 and 5.0 ppm CdCl2 respectively. It has been revealed from the results of this study that cadmium produced genotoxic effects in fish.

Cytogenetic evaluation of Fansidar on human lymphocyte chromosomes in vitro.

Fansidar is a fixed combination of two antimalarial agents a diaminopyrimidine (Pyrimethamine) and a sulphonamide (Sulphadoxine) in the ratio 1:20- that have been used extensively worldwide for the treatment of Chloroquine resistant Plasmodium falciparum malaria, toxoplasmosis and pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. This study examined the effect of Fansidar on chromosomes in human lymphocyte culture. Fansidar was added to peripheral blood lymphocyte cultures in vitro at four different concentrations: 5, 15, 25 and 50 @l in the ratio 1:20, 3:60, 5:100 and 10:200 @g ml-1. Result shows that this drug induces moderate increase in the frequency of gaps, breaks and rearrangements. Therefore it can be concluded that Fansidar has moderate clastogenic effect on human chromosomes in vitro.

Anticlastogenic action of vitamin C against genotoxicity of estrogenic drug diethylstilbestrol (DES) in the human lymphocyte chromosomes.

Several sex steroids and estrogenic drugs are genotoxic in varying conditions and cause oxidative stress, which has been a field of interest to study the molecular mechanism of the genetic damage. Among the estrogenic drugs, a strong toxic effect is exerted by diethylstilbestrol (DES). In the present study it has been attempted to study its genotoxic effects in human lymphocyte assay system along with ameliorative or anticlastogenic effects of vitamin C. The drug was used with different dosage of concentrations on human lymphocytes administered in vitro. The parameters used were Sister Chromatid Exchanges (SCEs) and Chromosomal Aberrations (CAs). Higher levels of clastogeny and SCEs have been observed indicating significant damaging effect by the drug. Interesting ameliorating effects were observed in the presence of vitamin C which is a well-known antioxidant. The results support the possibility of practical application of natural protectors against the mutagenic/oenotoxic action of chemical mutagens.