Inhibitory effect of Bifidobacterium longum on colon, mammary, and liver carcinogenesis induced by 2-amino-3-methylimidazo[4,5-f]quinoline, a food mutagen
Reddy, B.S.; Rivenson, A.
Cancer Research 53(17): 3914-3918
1993
ISSN/ISBN: 0008-5472 PMID: 8358717 Document Number: 408372
The inhibitory effect of lyophilized cultures of Bifidobacterium longum on 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-induced carcinogenesis was investigated in male and female F344 rats. Beginning at 5 weeks old, male and female rats were divided into groups and fed on 1 of the high-fat, semipurified diets containing 0 and 0.5% lyophilized cultures of B. longum without or with IQ 125 mg/kg in the diet. All rats were necropsied during the 58th week. Dietary B. longum significantly inhibited the IQ-induced incidence (percentage of rats with tumours) of colon (100) and liver (80% inhibition) tumours and multiplicity (tumours/rat) of colon, liver and small intestinal tumours in male rats. In female rats, dietary supplementation of Bifidobacterium cultures also suppressed the IQ-induced mammary carcinogenesis to 50% and liver carcinogenesis to 27% of those observed in rats fed on the control diet, but the differences did not reach significance at P<0.05; however, the mammary tumour multiplicity (tumours/rat) was inhibited (P<0.05) in female rats fed on the diet containing Bifidobacterium cultures. It is suggested that Bifidobacterium supplements in the diet inhibit IQ-induced colon and liver tumours and to a lesser extent mammary tumours in F344 rats.