scholarly journals Inhibition of Drug Metabolizing Enzymes (Cytochrome P450) in Vitro as Well as in Vivo by Phyllanthus amarus SCHUM & THONN

2006 ◽  
Vol 29 (7) ◽  
pp. 1310-1313 ◽  
Author(s):  
Kuzhuvelil Bhaskarannair Hari Kumar ◽  
Ramadasan Kuttan
Keyword(s):  
Cytochrome P450 ◽  
Drug Metabolizing Enzymes ◽  
Phyllanthus Amarus ◽  
Metabolizing Enzymes

scholarly journals Effect of 4-(4-Chlorobenzyl)pyridine on Rat Hepatic Microsomal Cytochrome P450 and Drug-Metabolizing Enzymes in Vivo and in Vitro.

2001 ◽  
Vol 24 (5) ◽  
pp. 505-509 ◽  
Author(s):  
Yasuna KOBAYASHI ◽  
Naomi OHSHIRO ◽  
Tadanori SASAKI ◽  
Shogo TOKUYAMA ◽  
Takashi TOBE ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Drug Metabolizing Enzymes ◽  
Metabolizing Enzymes ◽  
Microsomal Cytochrome ◽  
Microsomal Cytochrome P450

Species Differences in the Response of Liver Drug-Metabolizing Enzymes to (S)-4-O-Tolylsulfanyl-2-(4-trifluormethyl-phenoxy)-butyric Acid (EMD 392949) in Vivo and in Vitro

2008 ◽  
Vol 36 (4) ◽  
pp. 702-714 ◽  
Author(s):  
Lysiane Richert ◽  
Gregor Tuschl ◽  
Catherine Viollon-Abadie ◽  
Nadège Blanchard ◽  
Alexandre Bonet ◽  
...  
Keyword(s):  
Butyric Acid ◽  
Species Differences ◽  
Drug Metabolizing Enzymes ◽  
Metabolizing Enzymes

scholarly journals Pharmacokinetic Interactions of Herbs with Cytochrome P450 and P-Glycoprotein

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hyun-Jong Cho ◽  
In-Soo Yoon
Keyword(s):  
Cytochrome P450 ◽  
Glycoprotein P ◽  
Metabolizing Enzymes ◽  
Herbal Products ◽  
P Glycoprotein ◽  
Concurrent Use ◽  
Substrate Drug ◽  
And Function

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 herbs can provide robust fundamentals for optimizing CYP and/or P-gp substrate drug-based therapy. Herein, we review ten popular medicinal and/or dietary herbs as perpetrators of CYP- and P-gp-mediated pharmacokinetic herb-drug interactions. The main focus is placed on previous works on the ability of herbal extracts and their phytochemicals to modulate the expression and function of CYP and P-gp in severalin vitroandin vivoanimal and human systems.

scholarly journals Variability in human drug metabolizing cytochrome P450 CYP2C9, CYP2C19 and CYP3A5 activities caused by genetic variations in cytochrome P450 oxidoreductase

2019 ◽  
Author(s):  
Maria Natalia Rojas Velazquez ◽  
Shaheena Parween ◽  
Sameer S Udhane ◽  
Amit V Pandey
Keyword(s):  
Cytochrome P450 ◽  
Drug Metabolism ◽  
Recombinant Proteins ◽  
Correct Diagnosis ◽  
Detailed Knowledge ◽  
Drug Metabolizing Enzymes ◽  
Metabolizing Enzymes ◽  
P450 Oxidoreductase ◽  
Cytochrome P450 Oxidoreductase

AbstractA broad spectrum of human diseases are caused by mutations in the NADPH cytochrome P450 oxidoreductase (POR). Cytochrome P450 proteins perform several reactions, including the metabolism of steroids, drugs, and other xenobiotics. In 2004 the first human patients with defects in POR were reported, and over 250 variations in POR are known. Information about the effects of POR variants on drug metabolizing enzymes is limited and has not received much attention. By analyzing the POR sequences from genomics databases, we identified potentially disease-causing variations and characterized these by in vitro functional studies using recombinant proteins. Proteins were expressed in bacteria and purified for activity assays. Activities of cytochrome P450 enzymes were tested in vitro using liposomes prepared with lipids into which P450 and P450 reductase proteins were embedded. Here we are reporting the effect of POR variants on drug metabolizing enzymes CYP2C9, CYP2C19, and CYP3A5 which are responsible for the metabolism of many drugs. POR Variants A115V, T142A, A281T, P284L, A287P, and Y607C inhibited activities of all P450 proteins tested. Interestingly, the POR variant Q153R showed a reduction of 20-50% activities with CYP2C9 and CYP2C19 but had a 400% increased activity with CYP3A5. The A287P is most common POR mutation found in patients of European origin, and significantly inhibited drug metabolism activities which has important consequences for monitoring and treatment of patients. In vitro, functional assays using recombinant proteins provide a useful model for establishing the metabolic effect of genetic mutations. Our results indicate that detailed knowledge about POR variants is necessary for correct diagnosis and treatment options for persons with POR deficiency and the role of changes in drug metabolism and toxicology due to variations in POR needs to be addressed.

scholarly journals In Vitro Antioxidant Potential and Effect of a Glutathione-Enhancer Dietary Supplement on Selected Rat Liver Cytochrome P450 Enzyme Activity

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Benoit B. N’guessan ◽  
Seth K. Amponsah ◽  
George J. Dugbartey ◽  
Kwabena D. Awuah ◽  
Eunice Dotse ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Dietary Supplement ◽  
Rat Liver ◽  
Inhibitory Effect ◽  
Antioxidant Potential ◽  
Total Phenolic ◽  
Drug Metabolizing Enzymes ◽  
Metabolizing Enzymes ◽  
Cyp Enzymes

Background. There is considerable evidence that many people take dietary supplements including those of herbal origin as an alternative therapy to improve their health. One such supplement, with an amalgam of constituents, is CellGevity®. However, the effect of this dietary supplement on drug-metabolizing enzymes is poorly understood, as it has not been studied extensively. Therefore, we investigated the effect of CellGevity dietary supplement on selected rat liver microsomal cytochrome P450 (CYP) enzymes, the most common drug-metabolizing enzymes. We also determined the total antioxidant potential of this dietary supplement in vitro. Methods. To determine the antioxidant potential of CellGevity dietary supplement, 2,2-diphenyl-2-picryl-hydrazyl (DPPH), total phenolic, and flavonoid assays were used after initial preparation of a solution form of the supplement (low dose, LD; 4 mg/kg and high dose, HD; 8 mg/kg). Rats received oral administration of these doses of the supplement for 7 days, after which the effect of the supplement on selected liver CYP enzymes was assessed using probe substrates and spectroscopic and high-performance liquid chromatographic methods. Rats which received daily administration of 80 mg/kg of phenobarbitone and distilled water served as positive and negative controls, respectively. Results. The IC50 value of the supplement 0.34 ± 0.07 mg/ml compared to 0.076±0.03 mg/ml of the BHT (positive control). The total phenolic content of the supplement at a concentration of 2.5 mg/ml was 34.97 g gallic acid equivalent (GAE)/100 g while its total flavonoid content at a concentration of 2.5 mg/ml was 6 g quercetin equivalent (QE)/100 g. The supplement significantly inhibited rat CYP2B1/2B2 (LDT 92.4%; HDT 100%), CYP3A4 (LDT 81.2%; HDT 71.7%), and CYP2C9 (LDT 21.7%; HDT 28.5%) while it had no significant inhibitory effect on CYPs 1A1/1A2, CYP1A2, and CYP2D6. Conclusion. CellGevity dietary supplement possesses moderate antioxidant activity in vitro and has an inhibitory effect on selected rat liver CYP enzymes, suggesting its potential interaction with drugs metabolized by CYP enzymes.

scholarly journals Evaluation of human primary intestinal monolayers for drug metabolizing capabilities

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Jennifer E. Speer ◽  
Yuli Wang ◽  
John K. Fallon ◽  
Philip C. Smith ◽  
Nancy L. Allbritton
Keyword(s):  
Phase I ◽  
Intestinal Epithelium ◽  
Brush Border ◽  
Functional Group ◽  
Drug Metabolizing Enzymes ◽  
Metabolizing Enzymes ◽  
Brush Border Enzymes ◽  
In Cells

Abstract Background The intestinal epithelium is a major site of drug metabolism in the human body, possessing enterocytes that house brush border enzymes and phase I and II drug metabolizing enzymes (DMEs). The enterocytes are supported by a porous extracellular matrix (ECM) that enables proper cell adhesion and function of brush border enzymes, such as alkaline phosphatase (ALP) and alanyl aminopeptidase (AAP), phase I DMEs that convert a parent drug to a more polar metabolite by introducing or unmasking a functional group, and phase II DMEs that form a covalent conjugate between a functional group on the parent compound or sequential metabolism of phase I metabolite. In our effort to develop an in vitro intestinal epithelium model, we investigate the impact of two previously described simple and customizable scaffolding systems, a gradient cross-linked scaffold and a conventional scaffold, on the ability of intestinal epithelial cells to produce drug metabolizing proteins as well as to metabolize exogenously added compounds. While the scaffolding systems possess a range of differences, they are most distinguished by their stiffness with the gradient cross-linked scaffold possessing a stiffness similar to that found in the in vivo intestine, while the conventional scaffold possesses a stiffness several orders of magnitude greater than that found in vivo. Results The monolayers on the gradient cross-linked scaffold expressed CYP3A4, UGTs 2B17, 1A1 and 1A10, and CES2 proteins at a level similar to that in fresh crypts/villi. The monolayers on the conventional scaffold expressed similar levels of CYP3A4 and UGTs 1A1 and 1A10 DMEs to that found in fresh crypts/villi but significantly decreased expression of UGT2B17 and CES2 proteins. The activity of CYP3A4 and UGTs 1A1 and 1A10 was inducible in cells on the gradient cross-linked scaffold when the cells were treated with known inducers, whereas the CYP3A4 and UGT activities were not inducible in cells grown on the conventional scaffold. Both monolayers demonstrate esterase activity but the activity measured in cells on the conventional scaffold could not be inhibited with a known CES2 inhibitor. Both monolayer culture systems displayed similar ALP and AAP brush border enzyme activity. When cells on the conventional scaffold were incubated with a yes-associated protein (YAP) inhibitor, CYP3A4 activity was greatly enhanced suggesting that mechano-transduction signaling can modulate drug metabolizing enzymes. Conclusions The use of a cross-linked hydrogel scaffold for expansion and differentiation of primary human intestinal stem cells dramatically impacts the induction of CYP3A4 and maintenance of UGT and CES drug metabolizing enzymes in vitro making this a superior substrate for enterocyte culture in DME studies. This work highlights the influence of mechanical properties of the culture substrate on protein expression and the activity of drug metabolizing enzymes as a critical factor in developing accurate assay protocols for pharmacokinetic studies using primary intestinal cells. Graphical abstract

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