Crude cacao Theobroma cacao extract reduces mutagenicity induced by benzo[a]pyrene through inhibition of CYP1A activity in vitro.
Polyphenols have been shown to have potent antioxidant activity, and therefore, food containing polyphenols is expected to contribute to the prevention of cancer. However, food contains not only polyphenols but also various other constituents. We used the Ames test to investigate the effects of crude extracts of whole cacao products, which are known to be rich in polyphenols, on the mutagenicity of benzo[a]pyrene (B[a]P) in Salmonella typhimurium strain TA 98 and tert-butyl hydroperoxide (t-BuOOH) in S. typhimurium strain TA 102. B[a]P induces mutagenicity by metabolic activation and t-BuOOH induces it by generation of free radicals. While white chocolate did not modulate the numbers of revertant colonies produced by B[a]P treatment, milk chocolate and cacao powder extracts did. On the other hand, surprisingly, none of the cacao products tested affected the number of revertant colonies when t-BuOOH was used as the mutagen. At maximum concentration (13.25 mg cacao powder/ml), the crude cacao powder extract reduced ethoxyresorufin O-deethylase activity to 17.4% of the control, suggesting that whole cacao products inhibit cytochrome P450 (CYP) 1A activity. In conclusion, inhibition of CYP1A activity by cacao products may prevent DNA damage by reducing metabolic activation of carcinogens.
Ohno
Marumi
M
Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, N18 W9, Kita-ku, Sapporo 060-0818, Japan.
Sakamoto
Kentaro Q
KQ
Ishizuka
Mayumi
M
Fujita
Shoichi
S
D000818:Animals; D001564:Benzo(a)pyrene; D002099:Cacao / Q000737:chemistry*; D019363:Cytochrome P-450 CYP1A1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D008297:Male; D009152:Mutagenicity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012486:Salmonella typhimurium / Q000187:drug effects*; D020122:tert-Butylhydroperoxide
D016166:Free Radical Scavengers; D010936:Plant Extracts; D001564:Benzo(a)pyrene; D020122:tert-Butylhydroperoxide; D019363:Cytochrome P-450 CYP1A1