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The possible involvement of nitric oxide in response of Solanum nigrum seedlings to Fe deficiency was investigated. Iron deficiency resulted in decreased shoot height and chlorophyll content and increased proliferation of root hairs and H2O2, K+ and Ca2+ content. NO donor S-nitrosoglutathione (GSNO) was effective in preventing Fe deficiency-induced increase in content of H2O2 and the ion uptake. The protective effects of GSNO were reversed by cPTIO, an NO scavenger, and tungstate, a nitrate reductase (NR) inhibitor. [ABSTRACT FROM AUTHOR]

Fecapentaene-12 (Fec-12), a compound thought to be responsible for much of the mutagenicity in fecal extracts from groups at high risk for colon cancer, was assayed for genotoxic potential in a battery of bacterial and mammalian cell short-term assays. This compound demonstrated significant mutagenic activity with tester strains TA104, TA100 and TA98, inducing approximately 1400, 700 and 100 revertants/μg, respectively. Fec-12 caused dose-dependent increases in unscheduled DNA synthesis in both rat hepatocytes and human fibroblasts, indicating its potential genotoxicity to mammalian as well as bacterial cells. Finally, Fec-12 had the ability to induce neoplastic transformation in mouse BALB/c 3T3 cells in the absence of exogenous metabolic activation. [ABSTRACT FROM PUBLISHER]

Fecapentaenes are mutagens found in human feces and may play a role in the pathogenesis of colon carcinoma. However, the genotoxk effects of fecapentaenes have not been previously studied in mammalian cells. We now report that fecapenta-ene-12 (fec-12), a prototype for these compounds, causes DNA single strand breaks, sister chromatid exchanges and mutations in cultured human fibroblasts. These results indicate that fec-12 is a potent genotoxic agent in human cells. [ABSTRACT FROM PUBLISHER]