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Showing 1 to 20 of 41 for “"Cytochrome P450 enzymes"”.
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BIOACTIVATION OF NATURAL DIETARY PRODRUGS BY SPECIFIC CYTOCHROME P450 ENZYMES
Tumour specific cytochrome P450 enzymes (CYPs) have recently been established as a novel target in anticancer drug discovery. The enzymes are used to activate nontoxic prodrugs with latent activity. Thus, the combination of tumour specific CYPs as ‘rescue enzymes’ with a suitable substrate provides …
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Characterisation of mammalian cytochrome P450 enzymes by their metabolic activities.
… and thereby characterise human liver microsomal cytochromes P450 responsible for the in vitro transformation of the B-carbolines, harmine and harman. Comparative studies were also carried out with rat liver microsomal P450s, where the effects of induction on the metabolism of harmine were …
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Cytochrome P450 enzymes and oxidative stress in tobacco/nicotine mediated HIV pathogenesis
… in cigarette smokers. The role of CYP enzymes has not been studied in context with smoking/nicotine and HIV pathogenesis. However, there are several elegant studies that show the involvement of CYP2A6, CYP2A13, CYP1A1, and CYP1B1 in smoking/nicotine-mediated toxicity leading to various …
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Developing novel systems for expression of intracellular membrane-bound human cytochrome P450 enzymes in baker’s yeast
Human cytochrome P450 (CYP) enzymes belong to a family of monooxygenase enzymes that are responsible for the metabolism, in a stereo-specific and stereo-selective manner, of diverse chemicals. These chemicals are often referred to as xenobiotics which are usually harmful and toxic to the human …
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Genetically engineering a new system for the expression of cytochrome P450 enzymes in insect cells using novel P450 reductases
Human cytochrome P450 enzymes (CYPs) are a superfamily of haem-binding monooxygenase enzymes involved in the metabolism of xenobiotics such as toxins, carcinogens and pharmaceutical drugs as well as in the biosynthesis of cholesterol, vitamins and steroids. In recent years, the area of drug …
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Exploring the effects of polymorphic variation on the stability and function of human cytochrome P450 enzymes in silico and in vitro
Cytochrome P450s are highly polymorphic enzymes responsible for the Phase I metabolism of over 80% of pharmaceutical drugs. Polymorphic variation can result in altered drug efficacy as well as adverse drug reactions so the lack of understanding of the effects of single amino acid substitutions on …
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Studies on pro-oxidant cytochrome P450 enzymes as drug discovery tools and the discovery that they also have a dual function as antioxidants
… roles in human cells. In this research, specific cytochrome P450s (CYPs) have been overexpressed in baker’s yeast with the following objectives in mind. (i) CYP1A1, CYP1A2, and CYP1B1 are enzymes highly up-regulated in lung cancers that are caused by inhaling or coming into contact with …
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Role of cytochrome P450 enzymes on alcohol/nicotine-mediated oxidative stress and cytotoxicity in monocytes/astrocytes: Implications for HIV-infected alcohol/tobacco users
… with other substances of abuse, such as tobacco. Cytochrome P450 2E1 (CYP2E1), which is induced by alcohol, is mainly involved in alcohol metabolism in the liver and extra-hepatic cells in chronic users. As a result of alcohol metabolism, CYP2E1 produces reactive oxygen species (ROS), which in …
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Investigation into the effects of the tobacco smoke procarcinogen benzo[a]pyrene on gene expression profiles in oesophageal cancer
… diol-epoxide (BPDE) by the CYP1 family of cytochrome P450 enzymes. BaP is a ligand for the aryl hydrocarbon receptor (AhR) which activates CYP1 gene transcription. Polymorphisms in these genes affect enzyme activity and therefore BaP bioactivation.
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Effects of Pycnogenol on Microsomal Cytochrome P450 Activity and Apoptosis
… <p>Metabolic activation of NNK depends upon cytochrome P450 enzymes (GYP). A second study looked at O-dealkylation of the substrates benzyloxyresorufin (BROD), ethoxyresorufin (EROD) and methoxyresorufin (MROD) linked to CYP2B1,2C6 and 1A2, respectively. Pycnogenol significantly inhibited …
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Approaches for assessing the presence and impact of thyroid hormone disrupting chemicals in Delphinid cetaceans
… toxic mechanism may include the induction of cytochrome P450 enzymes in the integument and liver, which could enhance the biotransformation of PCBs to hydroxylated metabolites (OH-PCBs). OH-PCBs may then interfere with thyroid hormone dependent neurodevelopment. The goals of these studies were …
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Resin Detoxification in Dendroctonus ponderosae: Functional Characterizations of Cytochrome P450 Proteins
… beneath the tree bark to reproduce. MPB use cytochrome P450 enzymes to both detoxify toxic monoterpene compounds present in tree resin as well as synthesize the pheromones used during tree invasion, suggesting an evolutionary link between the P450 proteins involved in the two processes. This …
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Differential gene expression analysis reveals functional roles of cryptic orange-pigmented organ in the colorless head kidney of Antarctic icefishes
… head kidney tissue. Transcription of many cytochrome P450 enzymes participating in steroidogenesis were upregulated, potentially leading to greater levels of ROS and peroxidation of the lipid-rich steroid producing orange body cells. Proline is known to act as an antioxidant, thus, the …
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Selective Oxidations by Iron(III) Porphyrins and Iron(III) Corroles
… predominant oxidation catalysts in Nature, the cytochrome P450 enzymes. This study focuses on the synthesis of porphyrin and corrole macrocyclic ligands and the corresponding iron(III) complexes which are fully characterized by UV-vis, GC/MS, and NMR spectroscopies. In this work, the potential …
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Selective Targeting of CYP3A5 Through Chemical and Genetic Approaches
<p>Cytochrome P450 enzymes function to catalyze a wide range of reactions important for various biological processes. In humans, the CYP3A subfamily is particularly critical for drug response. Within this family are CYP3A4 and CYP3A5, which collectively metabolize greater than half of all currently …
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Differential detoxification strategies in closely related herbivore species across a sharp ecotone
… these chemicals. One such method is the use of cytochrome P450 enzymes (CYPs), many of which are found in the liver. While there has been much study of CYPs in model systems, there has been little research on CYPs in wild systems. The woodrat species Neotoma lepida and N. bryanti live across a …
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Photochemical Oxidation Studies of Porphyrin Ruthenium Complexes
<p>In nature, transition metal containing enzymes display many biologically important, attractive and efficient catalytic oxidation reactions. Many transition metal catalysts have been designed to mimic the predominant oxidation catalysts in nature, namely, the cytochrome P450 enzymes. Ruthenium …
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Amelioration of acute and chronic toxicity of imidacloprid by dietary phytochemicals in honey bees (apis mellifera)
… presence of imidacloprid, honey bees upregulate cytochrome P450 enzymes, which are implicated in their detoxification; because consumption of the phytochemicals quercetin and p-coumaric acid, common constituents of honey and beebread, also upregulates cytochrome P450 monooxygenases, the presence …
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Approaches for assessing the presence and impact of thyroid hormone disrupting chemicals in delphinid cetaceans
… toxic mechanism may include the induction of cytochrome P450 enzymes in the integument and liver, which could enhance the biotransformation of PCBs to hydroxylated metabolites (OH-PCBs). OH-PCBs may then interfere with thyroid hormone dependent neurodevelopment. The goals of these studies were …
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