Cancer chemopreventive activity and metabolism of isoliquiritigenin, a compound found in licorice.

Isoliquiritigenin (2',4',4-trihydroxychalcone; ILG), a chalcone found in licorice root and many other plants, has shown potential chemopreventive activity through induction of phase II enzymes such as quinone reductase-1 in murine hepatoma cells. In this study, the in vivo metabolism of ILG was investigated in rats. In addition, ILG glucuronides and ILG-glutathione adducts were observed in human hepatocytes and in livers from rats treated with ILG.

Zapotin prevents mouse skin tumorigenesis during the stages of initiation and promotion.

Background: Zapotin, a flavonoid associated with Casimiroa edulis, was isolated as part of a program to discover natural inhibitors of carcinogenesis. Zapote blanco, the fruit of Casimiroa edulis, is consumed in many parts of the world. Zapotin is a non-toxic inducer of cellular differentiation, apoptosis and cell cycle arrest with cultured HL-60 promyelocytic cells.

Noninvasive prediction of prostatic DNA damage by oxidative stress challenge of peripheral blood lymphocytes.

To move closer to the goal of individualized risk prediction for prostate cancer, we used an in vivo canine model to evaluate whether the susceptibility of peripheral blood lymphocytes (PBLs) to oxidative stress-induced DNA damage could identify those individuals with the highest prostatic DNA damage. This hypothesis was tested in a population of 69 elderly male beagle dogs after they had completed a 7-month randomized feeding trial to achieve the broad range of dietary selenium status observed in U.S.

Quinone reductase induction as a biomarker for cancer chemoprevention.

Chemoprevention involves the use of natural or synthetic substances to reduce the risk of developing cancer. Strategies for protecting cells from initiation events include decreasing metabolic enzymes responsible for generating reactive species (phase I enzymes) while increasing phase II enzymes that can deactivate radicals and electrophiles known to intercede in normal cellular processes. Reduction of electrophilic quinones by quinone reductase is an important detoxification pathway.

Effects of dietary selenium supplementation on DNA damage and apoptosis in canine prostate.

The trace mineral selenium inhibits cancer development in a variety of experimental animal models. We used an in vivo canine model to evaluate the effects of dietary selenium supplementation on DNA damage in prostate tissue and on apoptosis in prostate epithelial cells. Sexually intact elderly male beagle dogs were randomly assigned to receive an unsupplemented diet (control group) or diets that were supplemented with selenium (treatment group), either as selenomethionine or as high-selenium yeast at 3 micro g/kg or 6 micro g/kg body weight per day for 7 months.