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Se Pu = Chinese Journal of... Aug 2020A sensitive, high-throughput method was established for the simultaneous determination of 12 antiepileptics in serum by ultra high performance liquid...
A sensitive, high-throughput method was established for the simultaneous determination of 12 antiepileptics in serum by ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The antiepileptics were gabapentin, lamotrigine, pregabalin, lacosamide, levetiracetam, topiramate, oxcarbazepine, clonazepam, sodium valproate, carbamazepine, phenobarbital and phenytoin sodium. Phenacetin and chlorzoxazone were used as internal standards. The antiepileptics and internal standards were extracted from serum by protein precipitation using acetonitrile as the precipitant. Chromatographic separation was achieved on an ACQUITY UPLC BEH C column with a gradient mobile phase comprising 10 mmol/L ammonium formate aqueous solution and methanol (containing 10 mmol/L ammonium formate) at a flow rate of 0.4 mL/min. Detection was performed in multiple reaction monitoring mode with ion mode switching. The results showed good linear trends in their respective concentration ranges and the correlation coefficients () were greater than 0.992. The spiked recoveries of the 12 antiepileptics in serum were 90.80%-114.0% at the three spiked levels. The intra-assay (=6) and inter-assay (=3) precisions were less than 13.2% and 14.8%, respectively. The method has high specificity and sensitivity, and it can be used for clinical blood concentration monitoring and pharmacokinetic studies of the 12 antiepileptics.
Topics: Anticonvulsants; Chromatography, High Pressure Liquid; Humans; Tandem Mass Spectrometry
PubMed: 34213181
DOI: 10.3724/SP.J.1123.2019.12025 -
Xenobiotica; the Fate of Foreign... Sep 2021Leonurine hydrochloride (LH) is derived from an ingredient of Houtt which is widely used for diseases in women.The influence of LH on the activity of cytochrome P450...
Leonurine hydrochloride (LH) is derived from an ingredient of Houtt which is widely used for diseases in women.The influence of LH on the activity of cytochrome P450 (CYPs) enzymes was investigated in this study.The effect of LH on CYPs enzyme activities were studied using the enzyme-selective substrates phenacetin (1A2), coumarin (2A6), diclofenac (2C9), S-mephenytoin (2C19), paclitaxel (2C8), dextromethorphan (2D6), chlorzoxazone (2E1) and testosterone (3A4). The IC value was calculated to express the strength of inhibition. The inhibition of CYPs was fitted with competitive or non-competitive inhibition models and corresponding parameters were also obtained.LH exerted inhibitory effects on the activity of CYP1A2, 2D6, and 3A4 with the IC values of 18.05, 15.13, and 20.09 μM, respectively. The obtained results showed that LH inhibited the activity of CYP1A2 and CYP2D6 via competitive manners ( = 8.667 μM and = 7.805 μM, respectively), while LH attenuated the CYP3A4 activity via a non-competitive manner ( = 9.507 μM). Moreover, LH showed time-dependent inhibition on CYP3A4 with the value of 4.31/0.044 min·μM.The inhibition of CYP1A2, CYP2D6, and CYP3A4 by LH, demonstrated , indicated the potential herb-drug interaction. Therefore, pharmacokinetic interactions involving LH and CYP1A2 or CYP2D6 or CYP1A2 substrates are likely to occur.
Topics: Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Gallic Acid; Humans; Microsomes, Liver
PubMed: 34176447
DOI: 10.1080/00498254.2021.1947544 -
Drug Metabolism and Pharmacokinetics Aug 2021Recently, in addition to carboxylesterases (CESs), we found that arylacetamide deacetylase (AADAC) plays an important role in the metabolism of some clinical drugs. In...
Recently, in addition to carboxylesterases (CESs), we found that arylacetamide deacetylase (AADAC) plays an important role in the metabolism of some clinical drugs. In this study, we screened for food-related natural compounds that could specifically inhibit human AADAC, CES1, or CES2. AADAC, CES1, and CES2 activities in human liver microsomes were measured using phenacetin, fenofibrate, and procaine as specific substrates, respectively. In total, 43 natural compounds were screened for their inhibitory effects on each of these enzymes. Curcumin and quercetin showed strong inhibitory effects against all three enzymes, whereas epicatechin, epicatechin gallate (ECg), and epigallocatechin gallate (EGCg) specifically inhibited AADAC. In particular, ECg and EGCg showed strong inhibitory effects on AADAC (IC values: 3.0 ± 0.5 and 2.2 ± 0.2 μM, respectively). ECg and EGCg also strongly inhibited AADAC-mediated rifampicin hydrolase activity in human liver microsomes with IC values of 2.2 ± 1.4 and 1.7 ± 0.4 μM, respectively, whereas it weakly inhibited p-nitrophenyl acetate hydrolase activity, which is catalyzed by AADAC, CES1, and CES2. Our results indicate that ECg and EGCg are potent inhibitors of AADAC.
Topics: Carboxylic Ester Hydrolases; Catechin; Curcumin; Enzyme Inhibitors; Flavonoids; Humans; Hydrolysis; Inactivation, Metabolic; Microsomes, Liver; Quercetin
PubMed: 34171773
DOI: 10.1016/j.dmpk.2021.100397 -
TheScientificWorldJournal 2021Knowledge of drug composition consumed on the streets and the identification and quantification of their adulterants is essential for understanding unexpected side...
Knowledge of drug composition consumed on the streets and the identification and quantification of their adulterants is essential for understanding unexpected side effects, tracking routes, and drug profiling. Therefore, this work aimed to determine the purity and to identify and quantify the main adulterants found in personal doses of cocaine (perico) and coca paste (bazuco) in Cartagena de Indias (Colombia). The data collected in this study describe a first attempt to introduce the qualitative and quantitative analyses of adulterants present in street drugs in Cartagena de Indias to improve surveillance. Through gas chromatography coupled to mass spectrometry (GC-MS), the purity and adulterants were quantified in 45 personal doses of cocaine powder and coca paste. 100% of the personal doses in the city were adulterated; caffeine, phenacetin, and levamisole were the main adulterants identified in cocaine. Besides the above, lidocaine was also found in coca paste. The purity of cocaine varied from 8% to almost 70%, with caffeine ranging from 6% to 42%. In the case of coca paste, the maximum content of cocaine found was 60%, while some samples contained as little as 14%. The results are consistent with other research in terms of the widespread use of caffeine as an adulterant, but they also follow the growing trend of the use of levamisole and phenacetin. The wide range of cocaine content in samples sold in the illicit market could cause undesirable effects on cocaine users who do not know the exact intended dose for consumption; so, this study intends to make these results available not only to academic, public health, and national security agencies but also to tourists entering Cartagena de Indias, so that they are aware of what they are consuming and the risks to which they are exposed.
Topics: Coca; Cocaine; Cocaine-Related Disorders; Colombia; Drug Contamination; Gas Chromatography-Mass Spectrometry; Humans
PubMed: 34121949
DOI: 10.1155/2021/5562315 -
IUCrJ May 2021As the first step in the crystallization process, nucleation has been studied by many researchers. In this work, phenacetin (PHEN) was selected as a model compound to...
As the first step in the crystallization process, nucleation has been studied by many researchers. In this work, phenacetin (PHEN) was selected as a model compound to investigate the relationship between the solvent and nucleation kinetics. Induction times at different supersaturation in six solvents were measured. FTIR and NMR spectroscopy were employed to explore the solvent-solute interactions and the self-association properties in solution. Density functional theory (DFT) was adopted to evaluate the strength of solute-solvent interactions and the molecular conformations in different solvents. Based on these spectroscopy data, molecular simulation and nucleation kinetic results, a comprehensive understanding of the relationship between molecular structure, crystal structure, solution chemistry and nucleation dynamics is discussed. Both the solute-solvent interaction strength and the supramolecular structure formed by the self-association of solute molecules affect the nucleation rate. The findings reported here shed new light on the molecular mechanism of nucleation in solution.
PubMed: 33953933
DOI: 10.1107/S2052252521003882 -
Analytical Methods : Advancing Methods... Apr 2021Cocaine is probably one of the most trafficked illicit drugs in the world. For this reason, police forces require fast, selective, and sensitive methods for cocaine...
Cocaine is probably one of the most trafficked illicit drugs in the world. For this reason, police forces require fast, selective, and sensitive methods for cocaine detection at crime scenes. Taking benefit of additive manufacturing, we demonstrate that 3D-printed graphene-polylactic acid (G-PLA) electrodes using the affordable fused deposition modelling technique can identify and quantify cocaine in seized drugs. The detection of cocaine based on its electrochemical oxidation on such electrodes was dramatically improved after an electrochemical surface treatment that generates reduced graphene oxide (anodic followed by a cathodic treatment). Square-wave voltammetric determination of cocaine was achieved in the concentration range between 20 and 100 μmol L-1, with a detection limit of 6 μmol L-1, and free from the interference of paracetamol, caffeine, phenacetin, lidocaine, benzocaine and levamisole, which are common adulterants found in seized drugs. The analytical characteristics obtained using 3D-printed G-PLA electrodes were comparable with those of previously reported electrochemical sensors, but presented the inherent advantages of the 3D-printing technology that enables low-cost, reproducible, and large-scale production of such electrodes in remote areas combined with the use of an environmentally-friendly biopolymer.
PubMed: 33885677
DOI: 10.1039/d1ay00181g -
Life Sciences Jul 2021Human carboxylesterases (CESs) and arylacetamide deacetylase (AADAC) are serine-esterase enzymes catalyzing the hydrolysis of many compounds containing esters, amides,...
AIMS
Human carboxylesterases (CESs) and arylacetamide deacetylase (AADAC) are serine-esterase enzymes catalyzing the hydrolysis of many compounds containing esters, amides, thioesters, or acetyl groups. This study aimed to investigate the presence, kinetic parameters, and inhibition of CES1, CES2, and AADAC in A549, H460, and H727 pulmonary cells in both living cells and S9 fractions.
MATERIALS AND METHODS
The p-nitrophenyl acetate (pNPA) and 4-methylumbelliferyl acetate (4-MUA) were used as non-selective esterase substrates, whereas phenacetin as selective AADAC substrate. CESs activities were also investigated in living cells by cellular bioimaging using selective fluorescent probes.
KEY FINDINGS
AADAC gene was detected in A549 and H460 cells; nevertheless, arylesterase activity was not found in relative S9 fractions. Besides, CES1 and CES2 were expressed to a different extent by all lung cells, and enzymatic activities were quite overlapping each other. All enzymes exhibited a typical Michaelis-Menten saturation curve and, regarding 4-MUA, similar K values were found in both living cells and S9 fractions. Conversely, kinetic parameters relative to the pNPA hydrolysis by S9 fractions were significantly lower than those detected in living cells. Inhibition studies revealed that 4-MUA hydrolysis was inhibited by bis-p-nitrophenyl phosphate and phenylmethanesulfonyl fluoride more than loperamide; on the contrary, pNPA hydrolysis inhibition was limited with similar inhibition profiles being obtained in both living cells and S9 fractions. The presence of carboxylesterases was definitely confirmed by cellular bioimaging.
SIGNIFICANCE
These findings add information to esterase knowledge in pulmonary cells that could be used as in vitro models for toxicological and pharmacological studies.
Topics: A549 Cells; Carboxylesterase; Carboxylic Ester Hydrolases; Cell Line; Esterases; Humans; Hydrolysis; Lung; Microsomes, Liver; Nitrophenols; Phenacetin; Substrate Specificity; Umbelliferones
PubMed: 33864822
DOI: 10.1016/j.lfs.2021.119486 -
Die Pharmazie Apr 2021This study used human liver microsomes to assess pterostilbene's effect on the metabolic activity of cytochrome P450 (CYP) 1A2, CYP2C9, and CYP2D6. The metabolism of...
This study used human liver microsomes to assess pterostilbene's effect on the metabolic activity of cytochrome P450 (CYP) 1A2, CYP2C9, and CYP2D6. The metabolism of their substrates (phenacetin, tolbutamide, and dextromethorphan) was assayed by quantifying their relevant metabolites by HPLC. The IC value was used to express the strength of inhibition, and the value of a volume per dose index (VDI) was used to indicate the metabolic ability of the enzyme. In this study, pterostilbene inhibited CYP1A2, CYP2C9, and CYP2D6's metabolic activities . CYP2C9's activity was most significantly inhibited by pterostilbene; its IC50 value was 0.12±0.04 μM. The IC50 value of CYP1A2 and CYP2D6 was 56.3±10.4 μM and 62.33±11.4 μM, respectively. The finding that suggests that pterostilbene has the potential to interact with CYP2C9 substrates . These results warrant clinical studies to assess the significance of these interactions.
Topics: Cytochrome P-450 CYP1A2; Cytochrome P-450 CYP1A2 Inhibitors; Cytochrome P-450 CYP2C9; Cytochrome P-450 CYP2C9 Inhibitors; Cytochrome P-450 CYP2D6; Cytochrome P-450 CYP2D6 Inhibitors; Humans; Inhibitory Concentration 50; Microsomes, Liver; Stilbenes
PubMed: 33849700
DOI: 10.1691/ph.2021.1304 -
Frontiers in Oncology 2021Melanoma is the most aggressive form of skin cancer and the most rapidly expanding cancer in terms of worldwide incidence. If primary cutaneous melanoma is mostly...
Melanoma is the most aggressive form of skin cancer and the most rapidly expanding cancer in terms of worldwide incidence. If primary cutaneous melanoma is mostly treated with a curative wide local excision, malignant melanoma has a poor prognosis and needs other therapeutic approaches. Angiogenesis is a normal physiological process essential in growth and development, but it also plays a crucial role in crossing from benign to advanced state in cancer. In melanoma progression, angiogenesis is widely involved during the vertical growth phase. Currently, no anti-angiogenic agents are efficient on their own, and combination of treatments will probably be the key to success. In the past, phenacetin was used as an analgesic to relieve pain, causing side effects at large dose and tumor-inducing in humans and animals. By contrast, low-dilution is often used in skin febrile exanthema, patches profusely scattered on limbs, headache, or flushed face without side effects. Herein are described the , , and anti-angiogenic and anti-tumoral potentials of low-dilution in a B16F1 tumor model and endothelial cells. We demonstrate that low-diluted inhibits tumor growth and tumor vascularization and thus increases the survival time of B16F1 melanoma induced-C57BL/6 mice. Moreover, modulates the lung metastasis in a B16F10 induced model. and , we evidence that low-diluted inhibits the migration and the recruitment of endothelial cells and leads to an imbalance in the pro-tumoral macrophages and to a structural malformation of the vascular network. All together these results demonstrate highly hopeful anti-tumoral, anti-metastatic, and anti-angiogenic effects of low-dilution on melanoma. Continued studies are needed to preclinically validate low-dilution as a complementary or therapeutic strategy for melanoma treatment.
PubMed: 33747916
DOI: 10.3389/fonc.2021.597503 -
Frontiers in Pharmacology 2020Poziotinib is an orally active, irreversible, pan-HER tyrosine kinase inhibitor used to treat non-small cell lung cancer, breast cancer, and gastric cancer. Poziotinib...
Poziotinib is an orally active, irreversible, pan-HER tyrosine kinase inhibitor used to treat non-small cell lung cancer, breast cancer, and gastric cancer. Poziotinib is currently under clinical investigation, and understanding its drug-drug interactions is extremely important for its future development and clinical application. The cocktail method is most suitable for evaluating the activity of cytochrome P450 enzymes (CYPs). As poziotinib is partially metabolized by CYPs, cocktail probes are used to study the interaction between drugs metabolized by each CYP subtype. Midazolam, bupropion, dextromethorphan, tolbutamide, chlorzoxazone, phenacetin, and their metabolites were used to examine the effects of poziotinib on the activity of cyp1a2, 2b1, 2d1, 2c11, 2e1, and 3a1/2, respectively. The experiment was carried out by using rat liver microsomes (RLMs), whereas the experiment involved the comparison of the pharmacokinetic parameters of the probes after co-administration with poziotinib to rats to those of control rats treated with only probes. UPLC-MS/MS was used to detect the probes and their metabolites in rat plasma and rat liver microsomes. The results revealed that the half-maximal inhibitory concentration values of bupropion and tolbutamide in RLMs were 8.79 and 20.17 μM, respectively, indicating that poziotinib showed varying degrees of inhibition toward cyp2b1 and cyp2c11. Poziotinib was a competitive inhibitor of cyp2b1 and cyp2c11, with Ki values of 16.18 and 17.66 μM, respectively. No time- or concentration-dependence of inhibition by poziotinib was observed toward cyp2b1 and cyp2c11 in RLMs. Additionally, no obvious inhibitory effects were observed on the activity of cyp1a2, cyp2d1, cyp2e1, and cyp3a1/2. analysis revealed that bupropion, tolbutamide, phenacetin, and chlorzoxazone showed significantly different pharmacokinetic parameters after administration ( < 0.05); there was no significant difference in the pharmacokinetic parameters of dextromethorphan and midazolam. These results show that poziotinib inhibited cyp2b1 and cyp2c11, but induced cyp1a2 and cyp2e1 in rats. Thus, poziotinib inhibited cyp2b1 and cyp2c11 activity in rats, suggesting the possibility of interactions between poziotinib and these CYP substrates and the need for caution when combining them in clinical settings.
PubMed: 33746741
DOI: 10.3389/fphar.2020.593518