Search

Heterocyclic aromatic amines (HAAs) including PhIP and MeIQx are potential carcinogens found mainly in well-done meat. Consuming brassica vegetables was shown to promote metabolisms of HAAs due to the action of isothiocyanates. Previous in vivo studies showed that phenethyl isothiocyanate (PEITC) was a potent stimulator of phase II detoxification enzymes. Nevertheless, the clinical effect of PEITC-rich vegetables on detoxification of HAAs in grilled meat was unknown. This research aimed to investigate the effect of a PEITC-rich vegetable sauce on the detoxification of HAAs in healthy people consuming grilled meat. A randomized crossover placebo-controlled trial was conducted in twenty-one healthy participants. They were randomly assigned into three groups. The participants consumed a single meal of grilled beef with 100 g of the placebo sauce and 100 g and 50 g of the vegetable sauce. All participants consumed all sauces in an alternating random sequence. After de-conjugation with β-glucuronidase, the HAA metabolites in urine were measured by using LC/MS-MS. Compared to the placebo sauce, consuming grilled beef with 100 g of the vegetable sauce increased the urinary excretion of both PhIP and MeIQx glucuronide metabolites ( p -value <0.0001), while consuming 50 g of the sauce significantly increased only MeIQx metabolites ( p -value <0.05). The findings of this study suggested that consuming grilled meat with 100 g of the PEITC-rich vegetable sauce could increase the urinary excretion of PhIP and MeIQx glucuronide metabolites. Since meat eaters usually consume a low amount of vegetables, the PEITC-rich vegetable sauce could be an alternative approach to provide detoxification benefits from vegetable-derived compounds.

Alcohol consumption leads to acetaldehyde accumulation, especially in people with mutant aldehyde dehydrogenase 2 gene ( ALDH2 ). Novel strategies to promote acetaldehyde detoxification are required to prevent alcohol-related toxicity. Probiotic bacteria such as Lactobacillus rhamnosus GG (LGG) were shown to have in vitro capacity to detoxify acetaldehyde. This randomized, blinded, placebo-controlled cross-over trial investigated the effect of LGG fermented milk in people with ALDH2 polymorphisms after moderate alcohol intake. Ten healthy wild-type and ten heterozygous mutant ALDH2 Thai men were block randomized into two groups. Each group consumed a different sequence of 150 mL fermented milk containing 10 8 CFU mL -1 LGG and lactic-acidified milk (placebo), followed by five glasses of beer (0.4 g ethanol per kg body weight), with a one-week wash-out. Consuming LGG fermented milk before alcohol reduced areas under the response curves of blood and salivary acetaldehyde in wild-type and heterozygous mutant ALDH2 individuals ( p < 0.05 and p < 0.01, respectively). Interestingly, participants with mutant ALDH2 responded better than wild-type participants for salivary acetaldehyde (90% vs. 70%, p < 0.001). Their durations of flushing were reduced when consuming LGG milk. Regardless of ALDH2 status, 10 5 CFU mL -1 LGG was retained in saliva at least 3.5 h after milk consumption. In conclusion, intake of LGG fermented milk before drinking alcohol reduces blood and salivary acetaldehyde levels and duration of flushing in drinkers with wild-type and heterozygous mutant ALDH2 . The addition of exogenous capacity to detoxify acetaldehyde using the probiotic product could be a potential strategy to promote the alleviation of exposure to reactive and carcinogenic acetaldehyde associated with alcohol drinking in individuals with defective ALDH2 enzyme.

High doses of β-phenylethyl isothiocyanate (PEITC), a phytochemical in cruciferous vegetables, are not feasible for consumption due to a strong mouth-tingling effect. This study investigated the anti-cancer effect of PEITC at sensory acceptable doses. In vitro, PEITC was selectively toxic to oral cancer cells (CAL-27, FaDu, SCC4, SCC 9, SCC15, SCC25 and TU138), compared to oral keratinocytes (OKF6/TERT2 and NOK/Si). In vivo, 5 and 10 mg kg-1 PEITC, equivalent to human organoleptically acceptable doses, retarded tumor growth and prolonged the survival of mice bearing p53-mutated oral cancer cells - TU138 xenograft. Mechanistically, PEITC induced ROS accumulation, nuclear translocation of p53 and p21 and G1/S cell cycle arrest in vitro; increased p53 and 8-oxo-dG levels; and decreased Ki-67 intense/mild staining ratios without TUNEL changes in vivo. These findings suggested that the sensory acceptable doses of PEITC selectively induced ROS-mediated cell cycle arrest leading to delayed tumor progression and extended survival. PEITC could be a functional ingredient for oral cancer prevention.