Different roles of individual forms of human cytochrome P-450 (CYP) in the oxidation of 7-ethoxycoumarin and chlorzoxazone were investigated in liver microsomes of different human samples, and the microsomal activities thus obtained were predicted with kinetic parameters obtained from cDNA-derived recombinant CYP enzymes in microsomes of Trichoplusia ni cells. Of 14 forms of recombinant CYP exa...

Background Dietary antioxidants protect tissues and organs against insecticides/xenobiotic-induced damage. In the present study, we evaluated the results of exposure to synthetic pyrethroid insecticides, cypermethrin (Cyp) and deltamethrin (Del) and possible protective effects of curcumin and quercetin on reproductive system in male Wistar rats. MATERIALS AND METHODS In this controlled experi...

Cytochrome P450 enzymes (CYP) play a pivot role in phase I of xenobiotic biotransformation. Many of CYP enzymes are known to be polymorphic, with many allelic variants. As a consequence of huge number of possible allele combinations, a wide range of metabolic activity can be observed among patients in population. Individual CYP activity may be also affected by various xenobiotics – either induc...

Through their unique oxidative chemistry, cytochrome P450 monooxygenases (CYPs) catalyze the elimination of most drugs and toxins from the human body. Protein-protein interactions play a critical role in this process. Historically, the study of CYP-protein interactions has focused on their electron transfer partners and allosteric mediators, cytochrome P450 reductase and cytochrome b5. However,...

The concurrent use of drugs and herbal products is becoming increasingly prevalent over the last decade. Several herbal products have been known to modulate cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp) which are recognized as representative drug metabolizing enzymes and drug transporter, respectively. Thus, a summary of knowledge on the modulation of CYP and P-gp by commonly used her...

Objective: Morphology and functional role of PDGFRα cells have been recently characterized in the detrusor muscle layer. Detrusor relaxation is caused by activation of small conductance Ca activated-K (SK) channels and purinergic inhibitory responses in detrusor PDGFRα cells. Loss of PDGFRα cells or alteration of P2Y receptors and SK channels will affect detrusor excitability. Cyclophosphamide ...

Cyclophilin (CyP) is a peptidyl prolyl cis/trans isomerase, catalyzing the cis-trans isomerization of proline residues in proteins. CyP plays key roles in several different aspects of cellular physiology including the immune response, transcription, mitochondrial function, cell death, and chemotaxis. In addition to these cellular events, a number of reports demonstrated that CyP plays a critica...

1-Phenylazo-2-hydroxynaphthol (Sudan I, C.I. Solvent Yellow 14) is a liver and urinary bladder carcinogen in mammals. We compared the ability of hepatic microsomal samples from different species including human to metabolize Sudan I. Comparison between experimental animals and human cytochromes P450 (CYP) is essential for the extrapolation of animal carcinogenicity data to assess human health r...

Xenobiotics, including drugs, can influence cytochrome P450 (CYP) activity by upregulating the transcription of CYP genes. To minimize potential drug interactions, it is important to ascertain whether a compound will be an inducer of CYP enzymes early in the development of new therapeutic agents. In vivo and in vitro studies are reported that demonstrate the use of liver and intestinal slices a...