Background and Aims: The cytochrome P450 1A1 (CYP1A1) plays a curial role in phase I metabolism of polycyclic aromatic hydrocarbons to their ultimate biologically active intermediates that have potential reproductive toxicity in men. Reproductive functions in men may be impaired by many environmental, physiologic, and genetic factors. The majority of the environmental factors are xenobiotics. M...

The human body is exposed to a wide array of xenobiotics in one’s lifetime, from food components to environmental toxins to pharmaceuticals, and has developed complex enzymatic mechanisms to detoxify these substances. These mechanisms exhibit significant individual variability, and are affected by environment, lifestyle, and genetic influences. The scientific literature suggests an association ...

The effect of xenobiotics (phenobarbital and atrazine) on the expression of Drosophila melanogaster CYP genes encoding cytochromes P450, a gene family generally associated with detoxification, was analyzed by DNA microarray hybridization and verified by real-time RT-PCR in adults of both sexes. Only a small subset of the 86 CYP genes was significantly induced by the xenobiotics. Eleven CYP gene...

Plants contain large numbers of family 1 UDP-glucose-dependent glycosyltransferases (UGTs), including members that conjugate xenobiotics. Arabidopsis contains 107 UGT genes with 99 family members successfully expressed as glutathione transferase (GST)-fusion proteins in E. coli. A high-throughput catalytic screen was developed based on quantification of the fusion by measuring GST activity. UGT...

Hepatocyte nodules, structures consistently seen in every model of liver carcinogenesis well before the first appearance of cancer, were examined with respect to some Phase I and Phase II components considered to be important in the metabolism of carcinogens and other xenobiotics. Phase I components are those related to the metabolism of xenobiotics and include microsomal cytochromes P-450 and ...

The MRP (multidrug resistance protein) gene, a member of the ubiq ultous superfamily of ATP-binding cassette transporters, is associated with the multidrug resistance of mammalian cells to natural product anticancer agents. We have previously shown that abrogation of MRP expression by gene targeting leads to hypersensitivity to several drugs. In two independently produced MB? double knockout cl...

Like other constituents of ecosystems, insects are exposed to the action of many man-made chemicals, some of which accumulate in live and inanimate parts of the environment. Insects constitute an important group of organisms, because of the diversity of their morphology and physiology, their abundance, economic importance, and numerous effects on human health. Insects seem to display the greate...

Lolium perenne, which is a major component of pastures, lawns, and grass strips, can be exposed to xenobiotic stresses due to diffuse and residual contaminations of soil. L. perenne was recently shown to undergo metabolic adjustments in response to sub-toxic levels of xenobiotics. To gain insight in such chemical stress responses, a de novo transcriptome analysis was carried out on leaves from ...

The MRP (multidrug resistance protein) gene, a member of the ubiquitous superfamily of ATP-binding cassette transporters, is associated with the multidrug resistance of mammalian cells to natural product anticancer agents. We have previously shown that abrogation of MRP expression by gene targeting leads to hypersensitivity to several drugs. In two independently produced MRP double knockout clo...

BACKGROUND The phase II detoxification enzymes execute a major protective role against xenobiotics as well as endogenous toxicants. To understand how xenobiotics regulate phase II enzyme expression, acrylamide was selected as a model xenobiotic chemical, as it induces a large number and a variety of phase II enzymes, including numerous glutathione S-transferases (GSTs) in Caenorhabditis elegans...