Flavonoids are present in fruits, vegetables and beverages derived from plants, and in many dietary supplements or herbal remedies. A number of naturally occurring flavonoids have been shown to modulate the CYP450 system, including the induction or inhibition of these enzymes. This review focuses on the flavonoid effects on cytochrome P450 (CYP) enzyme CYP1, 2E1, 3A4 and 19. Flavonoids alter CYPs by various mechanisms, including the stimulation of gene expression via specific receptors and/or CYP protein, or mRNA stabilization and so on. But in vivo and in vitro, the effects of flavonoids are not always coincident as a result of concentrations of flavonoids, genetic and environmental factors. As well, flavonoids may interact with drugs through the induction or inhibition of their metabolism. Much attention should be paid to the metabolism interaction of the flavonoids when coadministered with other drugs.
Animals ; Aromatase ; genetics ; metabolism ; Cytochrome P-450 CYP1A1 ; antagonists & inhibitors ; genetics ; metabolism ; Cytochrome P-450 CYP2E1 ; genetics ; metabolism ; Cytochrome P-450 CYP2E1 Inhibitors ; Cytochrome P-450 CYP3A ; genetics ; metabolism ; Cytochrome P-450 CYP3A Inhibitors ; Cytochrome P-450 Enzyme Inhibitors ; Cytochrome P-450 Enzyme System ; genetics ; metabolism ; Enzyme Activation ; drug effects ; Flavonoids ; pharmacology ; Humans ; RNA, Messenger ; genetics ; metabolism

Rotundine (1 micromol L(-1)) was incubated with a panel of rCYP enzymes (1A2, 2C9, 2C19, 2D6 and 3A4) in vitro. The remained parent drug in incubates was quantitatively analyzed by an Agilent LC-MS. CYP2C19, 3A4 and 2D6 were identified to be the isoenzymes involved in the metabolism of rotundine. The individual contributions of CYP2C19, 3A4 and 2D6 to the rotundine metabolism were assessed using the method of total normalized rate to be 31.46%, 60.37% and 8.17%, respectively. The metabolites of rotundine in incubates were screened with ESI-MS at selected ion mode, and were further identified using MS2 spectra and precise molecular mass obtained from an Agilent LC/Q-TOF-MSMS, as well as MS(n) spectra of LC-iTrap-MS(n). The predominant metabolic pathway of rotundine in rCYP incubates was O-demethylation. A total 5 metabolites were identified including 4 isomerides of mono demethylated rotundine and one di-demethylated metabolite. The results also showed that CYP2C19, 2D6 and 3A4 mediated O-demethylation of methoxyl groups at different positions of rotundine. Furthermore, the ESI-MS cleavage patterns of rotundine and its metabolites were explored by using LC/Q-TOF-MSMS and LC/iTrap-MS(n) techniques.
Analgesics, Non-Narcotic ; metabolism ; Aryl Hydrocarbon Hydroxylases ; metabolism ; Berberine Alkaloids ; metabolism ; Chromatography, Liquid ; Cytochrome P-450 CYP1A2 ; metabolism ; Cytochrome P-450 CYP2C19 ; Cytochrome P-450 CYP2C9 ; Cytochrome P-450 CYP2D6 ; metabolism ; Cytochrome P-450 CYP3A ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Dopamine Antagonists ; metabolism ; Humans ; Isoenzymes ; metabolism ; Methylation ; Recombinant Proteins ; metabolism ; Spectrometry, Mass, Electrospray Ionization

To study the enzyme kinetics of ligustilide metabolism and the effects of selective CYP450 inhibitors on the metabolism of ligustilide in liver microsomes of rat, a LC-MS method was established for quantitative analysis of ligustilide in liver microsomes incubation system with nitrendipine as internal standard. The determination m/z for ligustilide was 173, and for nitrendipine, 315. An optimum incubation system was found and various selective CYP inhibitors were used to investigate their inhibitory effects on the metabolism of ligustilide. The results showed that enzyme kinetics of ligustilide could be significantly inhibited by ketoconazole, trimethoprim and a-naphthoflavon but scarcely inhibited by omeprazole, 4-methylpyrazole and quinidine. Therefore, CYP3A4, CYP2C9 and CYP1A2 are the major isoenzyme participated in in vitro metabolism of ligustilide.
4-Butyrolactone ; analogs & derivatives ; metabolism ; Animals ; Benzoflavones ; pharmacology ; Cytochrome P-450 CYP1A2 ; Cytochrome P-450 CYP3A ; Cytochrome P-450 Enzyme Inhibitors ; Cytochrome P-450 Enzyme System ; Cytochromes ; antagonists & inhibitors ; Ketoconazole ; pharmacology ; Kinetics ; Male ; Microsomes, Liver ; metabolism ; Rats ; Rats, Sprague-Dawley ; Trimethoprim ; pharmacology

Torsade de pointes is a life-threatening, polymorphic ventricular tachycardia associated with prolongation of the QTc interval. Although torsade de pointes is found in many clinical settings, it is mostly drug induced. Similar problems have been described with nonsedating H1-selective antihistamines like terfenadine and astemizole. The increased risks of both H1-antihistamines were associated with exposure to supratherapeutic doses or concomitant exposure to the cytochrome P-450 inhibitors, ketoconazole, erythromycin and cimetidine. We report a 51-year-old woman with torsade de pointes and a long QTc interval caused by the combined use of terfenadine and itraconazole. After discontinuation of these drugs and treatments with electrical cardioversion and magnesium sulfate, torsade de pointes and prolonged QTc interval were no longer observed and she was discharged in good condition with a normal ECG. In conclusion, physicians should be aware that terfenadine and astemizole can cause torsade de pointes in rare cases.
Astemizole ; Cimetidine ; Cytochrome P-450 Enzyme System ; Electric Countershock ; Electrocardiography ; Erythromycin ; Female ; Histamine Antagonists ; Humans ; Itraconazole* ; Ketoconazole ; Magnesium Sulfate ; Middle Aged ; Tachycardia, Ventricular ; Terfenadine* ; Torsades de Pointes*

There are numerous drug interactions related to many psychotropic and cardiovascular medications. Firstly, the principles in predicting drug interactions are discussed. Cytochrome P (CYP) 450 plays a significant role in the metabolism of these drugs that are substrates, inhibitors, or inducers of CYP450 enzymes. The two most significant enzymes are CYP2D6 and CYP3A4. The ability of psychotropic drugs to act as inhibitors for the enzymes may lead to altered efficacy or toxicity of co-administered cardiovascular agents as a substrate for the enzymes. The following is also a review of the known interactions between many commonly prescribed cardiovascular agents and psychotropic drugs. Most beta blockers are metabolized by CYP2D6, which may lead to drug toxicity when they use in combination with potent CYP2D6 inhibitors including bupropion, chlorpromazine, haloperidol, selective serotonin reuptake inhibitors, and quinidine. Concomitant administration of lithium with angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and diuretics may increase serum lithium concentrations and toxicity. Calcium channel blockers and cholesterol lowering agents are subject to interactions with potent inhibitors of CYP3A4, such as amiodarone, diltiazem, fluvoxamine, nefazodone, and verapamil. Prescribing antiarrhythmic drugs in conjunction with medications are known to prolong QT interval and/or inhibitors on a relevant CYP450 enzyme is generally not recommended, or needs watchful monitoring. Digoxin and warfarin also have warrant careful monitoring if co-administered with psychotropic drugs.
Amiodarone ; Angiotensin Receptor Antagonists ; Angiotensin-Converting Enzyme Inhibitors ; Anti-Arrhythmia Agents ; Bupropion ; Calcium Channel Blockers ; Cardiovascular Agents ; Chlorpromazine ; Cholesterol ; Cytochrome P-450 CYP2D6 ; Cytochrome P-450 Enzyme System ; Cytochromes ; Digoxin ; Diltiazem ; Diuretics ; Drug Interactions ; Drug Toxicity ; Fluvoxamine ; Haloperidol ; Lithium ; Psychotropic Drugs ; Quinidine ; Serotonin Uptake Inhibitors ; Triazoles ; Verapamil ; Warfarin

<p>OBJECTIVETo investigate the angiogenetic effects of endogenous and exogenous epoxyeicosatrienoic acids (EET) and the relevant signaling mechanisms involved.p><p>METHODSBovine aortic endothelial cells (BAEC) were incubated with synthetic EETs or infected with recombinant adeno-associated viruses (rAAV) containing CYP2C11-CYPOR, CYP2J2 or CYP102 F87V mutant to increase endogenous expression levels of EETs. BAEC proliferation measured by cell counting and chromatometry, migration assessed by transwell analysis, and capillary formation determined by chicken embryo chorioallantoic membrane assays (CAM) and tube formation tests on matrigel and angiogenesis were analysed in vivo. The potential involvement of various signaling pathways were explored using selective inhibitors.p><p>RESULTSTransfection with rAAV-2C11OR, rAAV-2J2 or rAAV-F87V promoted BAEC proliferation, migration, and capillary tubule formation. However, the effects of EETs on proliferation, migration and capillary tubule formation were attenuated by inhibitors of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3 kinase)/Akt pathways, and partially attenuated by endothelial nitric oxide synthase (eNOS) inhibitor, but not by a protein kinase C inhibitor. In a rat ischemic hind limb model, rAAV-mediated epoxygenase transfection induced angiogenesis.p><p>CONCLUSIONSArachidonic acid epoxygenase and its metabolites can promote angiogenesis through activating MAPK and PI3 kinase/Akt signaling pathways, and to some extent, the eNOS pathway, and the angiogenic effects may provide protection to ischemic tissues.p>
8,11,14-Eicosatrienoic Acid ; metabolism ; pharmacology ; Animals ; Cattle ; Cell Proliferation ; Cells, Cultured ; Chick Embryo ; Cytochrome P-450 Enzyme System ; metabolism ; Endothelial Cells ; metabolism ; Humans ; Male ; Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; metabolism ; Neovascularization, Physiologic ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; metabolism ; Rats ; Rats, Wistar ; Signal Transduction ; Transfection

It is essential for a successful drug to possess two basic characteristics: satisfactory pharmacological action with sufficient potency and selectivity; good druggability with eligible physicochemical, pharmacokinetic and safety profiles, as well as structural novelty. Promiscuity is defined as the property of a drug to act with multiple molecular targets and exhibit distinct pharmacological effects. Promiscuous drugs are the basis of polypharmacology and the causes for side effects and unsuitable DMPK. Drug promiscuity originates from protein promiscuity. In order to accommodate, metabolize and excrete various endo- and exogenous substances, protein acquired the capability during evolution to adapt a wide range of structural diversity, and it is unnecessary to reserve a specific protein for every single ligand. The structures of target proteins are integration of conservativity and diversity. The former is represented by the relatively conservative domains for secondary structures folding, which leads to overlapping in ligand-binding and consequent cross-reactivity of ligands. Diversity, however, embodies the subtle difference in structures. Similar structural domain may demonstrate different functions due to alteration of amino acid sequences. The phenomenon of promiscuity may facilitate the "design in" of multi-target ligands for the treatment of complicated diseases, whereas it should be appropriately handled to improve druggability. Therefore, one of the primary goals in drug design is to scrutinize and manipulate the "merits and faults" of promiscuity. This review discusses the application of promiscuity in drug design for receptors, enzymes, ion channels and cytochrome P450. It also briefly describes the methods to predict ligand promiscuity based on either target or ligand structures.
Cytochrome P-450 Enzyme System ; chemistry ; Drug Design ; Drug Discovery ; Drug Resistance, Multiple ; Drug-Related Side Effects and Adverse Reactions ; Enzyme Inhibitors ; chemistry ; Ion Channels ; chemistry ; Ligands ; Pharmaceutical Preparations ; chemistry ; metabolism ; Pharmacokinetics ; Pharmacology ; Protein Binding ; Protein Conformation ; Receptors, G-Protein-Coupled ; chemistry ; Receptors, Steroid ; agonists ; antagonists & inhibitors

Diverse signaling pathways have been proposed to regulate store-operated calcium entry (SOCE) in a wide variety of cell types. However, it still needs to be determined if all of these known pathways operate in a single cell type. In this study, we examined involvement of various signaling molecules in SOCE using human fibroblast cells (HSWP). Bradykinin (BK)-stimulated Ca2+ entry, previously shown to be via SOCE, is enhanced by the addition of vanadate, an inhibitor of tyrosine phosphatases. Furthermore, SOCE is regulated by cytochrome P-450, as demonstrated by the fact that the products of cytochrome P-450 activity (14,15 EET) stimulated SOCE while econazole, an inhibitor of cytochrome P450, suppressed BK-stimulated Ca2+ entry. In contrast, Ca2+ entry was unaffected by the guanylate cyclase inhibitor LY83583, or the membrane permeant cyclic GMP analog 8-bromo-cyclic GMP (8-Br-cGMP). Neither nitric oxide donors nor phorbol esters affected BK-stimulated Ca2+ entry. SOCE in HSWP cells is primarily regulated by tyrosine phosphorylation and the cytochrome P-450 pathway, but not by cyclic GMP, nitric oxide, or protein kinase C. Thus, multiple pathways do operate in a single cell type leading to the activation of Ca2+ entry and some of these signaling pathways are more prominently involved in regulating calcium entry in different cell types.
Vanadates/pharmacology ; Tetradecanoylphorbol Acetate/pharmacology ; Protein-Tyrosine-Phosphatase/*metabolism ; Phosphotyrosine/metabolism ; Phosphorylation/drug effects ; Nitric Oxide/metabolism ; Humans ; Fibroblasts ; Epidermal Growth Factor/pharmacology ; Enzyme Inhibitors/pharmacology ; Econazole/pharmacology ; Cytochrome P-450 Enzyme System/antagonists & inhibitors/*metabolism ; Cyclic GMP/analogs & derivatives/metabolism ; Cells, Cultured ; Calcium Channels/*metabolism ; Calcium/metabolism ; Bradykinin/pharmacology

Human protein tyrosine kinases play an essential role in carcinogenesis and have been recognized as promising drug targets. By the end of 2012, eight small molecule tyrosine kinase inhibitors (TKIs) have been approved by State Food and Drug Administration of China for cancer treatment. In this paper, the pharmacokinetic characteristics (absorption, distribution, metabolism and excretion) and drug-drug interactions of the approved TKIs are reviewed. Overall, these TKIs reach their peak plasma concentrations relatively fast; are extensively distributed and highly protein bound (> 90%); are primarily metabolized by CYP3A4; most are heavily influenced by CYP3A4 inhibitors or inducers except for sorafenib; are mainly excreted with feces and only a minor fraction is eliminated with the urine; and are substrate of the efflux transporters ABCB1 (P-gp) and ABCG2 (BCRP). Additionally, many of the TKIs can inhibit some CYP450 enzymes, UGT enzymes, and transporters. Gefitinib, erlotinib, dasatinib, and sunitinib are metabolized to form reactive metabolites capable of covalently binding to biomolecules.
Antineoplastic Agents ; pharmacokinetics ; pharmacology ; Crown Ethers ; pharmacokinetics ; pharmacology ; Cytochrome P-450 Enzyme System ; metabolism ; Dasatinib ; pharmacokinetics ; pharmacology ; Drug Interactions ; Erlotinib Hydrochloride ; pharmacokinetics ; pharmacology ; Glucuronosyltransferase ; metabolism ; Humans ; Imatinib Mesylate ; pharmacokinetics ; pharmacology ; Indoles ; pharmacokinetics ; pharmacology ; Niacinamide ; analogs & derivatives ; pharmacokinetics ; pharmacology ; Phenylurea Compounds ; pharmacokinetics ; pharmacology ; Protein Kinase Inhibitors ; pharmacokinetics ; pharmacology ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; Pyrimidines ; pharmacokinetics ; pharmacology ; Pyrroles ; pharmacokinetics ; pharmacology ; Quinazolines ; pharmacokinetics ; pharmacology