The Inhibitory Effect of Spices and Flavonoid Compounds on Formation of 2-amino-1-methyl-6-Phenylimidazo [4,5-b] Pyridine (PhIP) in a Model System

Abstract

Heterocyclic amines (HCAs) are a class of mutagenic and carcinogenic compounds generated when muscle foods are cooked at high temperatures. Exposure to HCAs has been linked to human cancers, among them colon, prostate, breast, and pancreatic cancers. 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) is a common, potentially harmful HCA that forms via the Maillard reaction. The health consequences of consuming HCAs have caused the International Agency for Research on Cancer (IARC) to list PhIP as a “possible human carcinogen.” Spices and flavonoid compounds have received considerable attention for their beneficial effect against HCA formation in our daily foods. In this study, a model system with 0.011 mmol glucose, 0.022 mmol creatinine, and 0.022 mmol phenylalanine in 90:10 diethylene glycol/water (v/v) was heat-treated at 180°C for 1 hour to test the formation of PhIP. Spices such as black pepper oil, piperine, D-limonene, P-cymene, and capsaicin and flavonoid compounds such as quercetin, apigenin, genistin, phlorizin, and catechin were added individually to the model system at three concentrations (125, 625, and 1250 ppm) to test their effect on PhIP formation. The PhIP contents were assessed using High-Performance Liquid Chromatography (HPLC). The results indicate that four out of five components of spices: black pepper oil, piperine, D-limonene, and capsaicin significantly (p < 0.05) reduced PhIP formation, while P-cymene had no significant effect on PhIP formation. All flavonoid compounds also had a significant (p < 0.05) effect on PhIP formation. These findings provide valuable information about spices and flavonoid compounds as protective agents against HCA formation.