Numerous chemical compounds are cytotoxic or carcinogenic to human beings and attention is now focusing on preventative strategies. One agent, oltipraz (OPZ), regarded as one of the most promising chemoprotectors, has been shown to be a potent inducer of phase II enzymes involved in the detoxification of carcinogens, including aflatoxins. However, little is known about its effects on global gen...

An N-acetylcysteine (NAC)/oltipraz (OLZ) combination was studied in healthy volunteer smokers who received daily NAC (1200 mg/day) and were randomized to weekly placebo (Arm A), OLZ 200 mg (Arm B), or 400 mg (Arm C). Treatment was for 12 weeks with follow-up at 16 weeks. The objective was to study toxicity and the modulation of pharmacodynamic end points. After treatment of 19 of a planned 60 s...

Oltipraz (OPZ) is currently being considered for human use to protect against aflatoxin B, (AFB)-induced hepatocarcinogenesis based on its proven protective effect in rats. The effectiveness of this treatment pre sumes that orthologous cytochrome P450 and glutathione S-transferase (GST) isozymes metabolize AFB in humans as they do in rats. In this study, alterations in the expression of multipl...

Oltipraz (OPZ) is currently being considered for human use to protect against aflatoxin B1 (AFB)-induced hepatocarcinogenesis based on its proven protective effect in rats. The effectiveness of this treatment presumes that orthologous cytochrome P450 and glutathione S-transferase (GST) isozymes metabolize AFB in humans as they do in rats. In this study, alterations in the expression of multiple...

Oltipraz (OPZ) is a potent chemopreventive agent against chemically-induced carcinogenesis in several animal models. It affects the expression and/or activity of xenobiotic-metabolizing enzymes and its effects are altered in the course of inflammation in liver. The present study was undertaken to analyse the effect of OPZ alone or in combination with Escherichia coli lipopolysaccharide (LPS) on...

Cancer chemoprevention is the use of specific natural or synthetic substances with the objective of reversing, suppressing, or preventing carcinogenic progression to invasive cancer. Currently, numerous chemopreventive agents are in various stages of development and testing. Part 1 of this two-part series provides an overview of issues unique to chemoprevention trials, including the use of surr...

A search of the literature using National Library of Medicine databases and individual cancer journal articles yielded over 500 compounds with published chemopreventive activity in animals. From these, an initial 16 agents or agent combinations have been evaluated in the following animal tumor models: mouse skin papillomas/carcinomas induced by 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylp...

In rodents, a diversity of compounds are able to protect against acute and chronic toxicities of various xenobiotics including carcinogens, at least in part through induction of drug-metabolizing enzymes including glutathione S-transferase (GST) enzymes. We have posed the question as to whether or not these compounds also induce GSTs in human liver. Primary human hepatocyte cultures were expose...