Mutagenicity of nicotine in Schistosoma mansoni - infected mice

Schistosomiasis is a widespread and serious infection in Egypt and many parts of the world, and tobacco smoking by infected patients is not uncommon. Evidence for association of either smoking or Schistosoma infection with carcinogenicity and/or mutagenicity has been reported. This study deals with the induction of chromosomal damage assessed by bone marrow micronucleus (MN) and chromosome aberration (CA) tests, as well as the analysis of chromosomal aberrations in diakinesis-metaphase I spermatocytes in male mice infected with Schistosoma mansoni cercariae and treated with nicotine. Schistosoma infection increased the percentage of micronucleated erythrocytes and total CAs in bone marrow cells. Analysis of meiotic chromosomes showed significant elevation in the Schistosoma-infected mice. Administration of nicotine to infected mice substantially increased the percentages of micronucleated cells and total CAs. The percentage of chromosomal abnormalities in spermatocyte metaphase-I cells increased significantly in Schistosoma-infected mice. The incidence of chromosomal aberrations of metaphase I spermatocytes showed a highly significant increase after nicotine treatment; the effect on infected mice was significantly higher than that noted on the non-infected group. The data obtained in this study suggest that animals afflicted with schistosomiasis with synergistic nicotine administration suffer from a higher genetic risk, and may serve as a warning to schistosomiasis patients. KEY WORDS: chromosome aberrations, micronucleus, carcinogenicity, spermatocyte diakinesis-I, mice. Egyptian Journal of Biology Vol.4 2002: 95-10