title: Suppressive effects of coffee on the SOS responses induced by UV and chemical mutagens.
abstract: SOS-inducing activity of UV or chemical mutagens (AF-2, 4NQO and MNNG) was strongly suppressed by instant coffee in Salmonella typhimurium TA1535/pSK1002. As decaffeinated instant coffee showed a similarly strong suppressive effect, it would seem that caffeine, a known inhibitor of SOS responses, is not responsible for the effect observed. The suppression was also shown by freshly brewed coffee extracts. However, the suppression was absent in green coffee-bean extracts. These results suggest that coffee contains some substance(s) which, apart from caffeine, suppresses SOS-inducing activity of UV or chemical mutagens and that the suppressive substance(s) are produced by roasting coffee beans.
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000037:antagonists & inhibitors; D002110:Caffeine / Q000032:analysis; D003069:Coffee / Q000032:analysis; D004260:DNA Repair / Q000187:drug effects*; D005668:Furylfuramide / Q000037:antagonists & inhibitors; D008769:Methylnitronitrosoguanidine / Q000037:antagonists & inhibitors; D009153:Mutagens / Q000037:antagonists & inhibitors*; D013014:SOS Response, Genetics / Q000187:drug effects* / Q000528:radiation effects; D012486:Salmonella typhimurium / Q000235:genetics; D014466:Ultraviolet Rays
chemical_list: D003069:Coffee; D009153:Mutagens; D005668:Furylfuramide; D008769:Methylnitronitrosoguanidine; D002110:Caffeine; D015112:4-Nitroquinoline-1-oxide