title: In vitro effect of aflatoxin B1 on the transcriptional activity of DNA template, chromatin and soluble DNA-dependent RNA polymerases in buffalo liver.
abstract: The effect of aflatoxin B1 on the DNA template and DNA-dependent RNA polymerases in buffalo liver was studied. Aflatoxin B1 inhibited both Mg2+- and Mn2+-activated RNA polymerases in a dose-dependent manner. At 10 micrograms the inhibition of both enzymes was almost complete. The inhibitory effect on the solubilized enzymes was higher than the chromatin-bound, suggesting a direct effect at the enzyme level. On the other hand, incubating DNA or deoxyribonucleoprotein (DNP) with 2 micrograms aflatoxin reduces its transcriptional capacity with a greater effect on the Mg2+-activated RNA polymerase than the Mn2+-activated enzyme. These results suggest that aflatoxin B1 inhibits in vitro transcription in buffalo liver at both enzyme and template levels.
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000633:toxicity*; D000818:Animals; D002020:Buffaloes; D002843:Chromatin / Q000201:enzymology*; D004247:DNA / Q000187:drug effects*; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors*; D005260:Female; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D000348:Aflatoxins; D002843:Chromatin; D004247:DNA; D016604:Aflatoxin B1; D012321:DNA-Directed RNA Polymerases