Siddique, Yasir HasanAfzal, Mohammad2005-06-132009-06-022005-06-132009-06-022005-06-13Siddique YH, Afzal M. Evaluation of genotoxic potential of norethynodrel in human lymphocytes in vitro. Journal of Environmental Biology. 2005 Jun; 26(2 Suppl): 387-92http://imsear.searo.who.int/handle/123456789/113810The genotoxicity study of a synthetic progestin norethynodrel, was carried out on human lymphocytes chromosomes using sister chromatid exchanges (SCEs), replication index (RI) and chromosomal aberrations (CAs) as parameters. The study was carried out in the presence and absence of metabolic activation (S9 mix). Norethynodrel was studied at three different concentrations (20, 40 and 60 microg/ml of peripheral blood lymphocyte culture) and was found non-genotoxic in the absence of metabolic activation. But in the presence of S9 mix norethynodrel increased SCE (p<0.03) and CA (p<0.005) frequencies and inhibits lymphocyte proliferation (p<0.03) at 60 microg/ml. The results suggest a genotoxic and cytotoxic effect of norethynodrel in human lymphocytes in vitro in the presence of S9 mix.engAnimalsCell Proliferation --drug effectsChromosome Aberrations --chemically inducedDNA Replication --drug effectsDose-Response Relationship, DrugHumansLymphocytes --drug effectsMicrosomes, Liver --metabolismMutagenicity TestsNorethynodrel --toxicityRatsRats, WistarComparative Study