BACKGROUND Cytochrome P450 monooxygenases (CYP) play an important role in the defense against inhaled toxicants, and expression of CYP enzymes may differ among various lung cells and tissue compartments. METHODS We studied the effects of tobacco smoke in volunteers and investigated gene expression of 19 CYPs and 3 flavin-containing monooxygenases, as well as isoforms of glutathione S-transfer...

Metabolism of administered drugs is determined by expression and activity of many drug-metabolizing enzymes, such as the cytochrome P450 (P450s) family members. Pregnane X receptor (PXR) is a master transcriptional regulator of many drug/xenobiotic-metabolizing enzymes, including P450s and drug transporters. In this study, we describe the functional analysis of four naturally occurring human PX...

Phytochemicals have been components of man's diet for millennia and are believed to have played a significant role in steering the functional development of xenobiotic metabolizing enzymes and transporters within the human gastrointestinal tract. Only recently, however, have plant secondary metabolites been recognized as modulators of human drug disposition. Despite exposure to thousands of str...

Prenatal exposure to low doses (0.25 or 0.5 or 1.0 mg/kg, p.o.) of deltamethrin, a type II pyrethroid insecticide, to pregnant dams from gestation days 5 to 21 (GD5-21) produced dose-dependent alterations in the ontogeny of xenobiotic metabolizing cytochrome P450 (CYP) isoforms in brain and liver of the offsprings. RT-PCR analysis revealed dose-dependent increase in the mRNA expression of cereb...

BACKGROUND Lung cancer is one of the most preventable causes of death globally both in developed and developing countries. Although it is well established that smokers develop lung cancer, there are some smokers who are free from the disease risk. The predisposition to lung cancer is attributed to genetic polymorphisms in xenobiotic metabolizing genes. Reports on assessment of xenobiotic metabo...

Polyphenols have been found in both rodent and human studies to exhibit diverse bioactivities though the mechanisms of action underlying those beneficial functions remain be fully elucidated. animals are widely recognized as xenobiotics known induce adaptive responses. Essential related include expressions antioxidative xenobiotic-metabolizing enzymes, heat shock proteins. Additionally, hormesi...

Epidemiological studies have shown that lung cancer is associated with tobacco and alcohol use, and is common in regions where these products are often consumed. Similar to other environmental toxins, tobacco requires metabolic activation and subsequent detoxification by a series of enzymes such as phase I enzymes i-e the cytochrome P450 enzymes (CYP) and phase II xenobiotic metabolizing enzyme...

Genetic polymorphisms of drug metabolizing enzymes are well recognized. This review presents molecular mechanisms, ontogeny and clinical implications of genetically determined intersubject variation in some of these enzymes. Included are the polymorphic enzymes N-acetyl transferase, cytochromes P4502D6 and 2C, which have been well described in humans. Information regarding other Phase I and Pha...