No abstract

No abstract

No abstract

-The potential of purple sweet potato color (PSPC) and red cabbage color (RCC), natural anthocyanin food colors, to modify colorectal carcinogenesis was investigated in male F344/DuCrj rats, initially treated with 1,2-dimethylhydrazine (DMH) and receiving 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) in the diet. After DMH initiation, PSPC and RCC were given at a dietary level of 5.0% in combination with 0.02% PhIP until week 36. No PSPC or RCC-treatment-related changes in clinical signs and body weight were found. Incidences and multiplicities of colorectal adenomas and carcinomas in rats initiated with DMH were clearly increased by PhIP. In contrast, lesion development was suppressed by RCC, or tended to be inhibited by PSPC administration. Furthermore, in the non-DMH initiation groups, induction of aberrant crypt foci (ACF) by PhIP was significantly decreased by RCC supplementation. The results thus demonstrate that while PhIP clearly exerts promoting effects on DMH-induced colorectal carcinogenesis, these can be reduced by 5.0% PSPC or 5.0% RCC in a diet under the present experimental conditions.

cDNAs encoding an enzyme with UDP-glucose:cyclo-DOPA 5-O-glucosyltransferase activity were isolated from four o'clocks and feather cockscombs. Phylogenetic analysis of the amino acid sequences deduced from the cDNAs show that they represent a single subclade distinct from those of other phenylpropanoid and flavonoid glucosyltransferases. Changes in the amount of transcripts of the cDNA in four o'clocks correlated with the accumulation of betanin during flower development. The cDNAs isolated here were candidates for the gene of the enzyme involved in another pathway of betacyanin biosynthesis via glucosylation at the cyclo-DOPA step rather than at the betanidin step.