title: Modifying role of dietary factors on the mutagenicity of aflatoxin B1: in vitro effect of plant flavonoids.
abstract: Eighteen flavonoids have been tested for their ability to inhibit the mutagenicity of aflatoxin B1 (AFB1) towards strains TA100 and TA98 of Salmonella typhimurium provided with a rat liver activation system. These flavonoids belong to 5 different groups: flavone, isoflavone, flavanone, flavanol and flavonol, and many individual members are natural products present in edible portions of a variety of food plants. Several flavonoids exhibited significant inhibitory ability in both strains. Flavonols in general are more active in this regard, while flavanones show a strain-specific response. The flavanol group of compounds did not display any activity. Among the most effective flavonoids are kaempferol, morin, fisetin, biochanin A and the glycoside rutin, all of which exhibit a dose-dependent inhibition pattern. Kaempferol and rutin, in particular, show exceptional activity inasmuch as, on a molar basis, only a 10-fold excess dose of each can inhibit the mutagenic activity of AFB1 in strain TA98 by 50%. The action of flavonoids is possibly mediated through interaction with microsomal activating enzymes. Previous evidence from this laboratory about their inhibitory action on DNA-adduct formation and metabolic activation together with the present results suggests that certain flavonoids, notably polyhydroxylated flavonols, may have potential anticarcinogenic activity against AFB1.
authors.affiliation: Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India.
authors.forename: A R
authors.initials: AR
authors.lastname: Francis
authors.forename: T K
authors.initials: TK
authors.lastname: Shetty
authors.forename: R K
authors.initials: RK
authors.lastname: Bhattacharya
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000037:antagonists & inhibitors / Q000633:toxicity*; D000818:Animals; D001711:Biotransformation / Q000187:drug effects; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000494:pharmacology*; D066298:In Vitro Techniques; D009152:Mutagenicity Tests; D009154:Mutation / Q000187:drug effects*; D010944:Plants; D051381:Rats
chemical_list: D000348:Aflatoxins; D005419:Flavonoids; D016604:Aflatoxin B1