The cytochrome P450 isoenzyme and some new opportunities for the prediction of negative drug interaction in vivo

In vitro evaluation of the selective cytotoxicity and genotoxicity of three synthetic ortho-nitrobenzyl derivatives in human cancer cell lines, with and without metabolic activation

Although the presence of nitro groups in chemicals can be recognized as structural alerts for mutagenicity and carcinogenicity, nitroaromatic compounds have attracted considerable interest as a class of agents that can serve as source of potential new anticancer agents. In the present study, the in vitro cytotoxicity, genotoxicity, and mutagenicity of three synthetic ortho-nitrobenzyl derivatives (named ON-1, ON-2 and ON-3) were evaluated by employing human breast and ovarian cancer cell lines. A series of biological assays was carried out with and without metabolic activation. Complementarily, computational predictions of the pharmacokinetic properties and druglikeness of the compounds were performed in the Swiss ADME platform. The MTT assay showed that the compounds selectively affected selectively the cell viability of cancer cells in comparison with a nontumoral cell line. Additionally, the metabolic activation enhanced cytotoxicity, and the compounds affected cell survival, as demonstrated by the clonogenic assay. The comet assay, the cytokinesis-block micronucleus assay, and the immunofluorescence of the γ-H2AX foci formation assay have that the compounds caused chromosomal damage to the cancer cells, with and without metabolic activation. The results obtained in the present study showed that the compounds assessed were genotoxic and mutagenic, inducing double-strand breaks in the DNA structure. The high selectivity indices observed for the compounds ON-2 and ON-3, especially after metabolic activation with the S9 fraction, must be highlighted. These experimental biological results, as well as the theoretical properties predicted for the compounds have shown that they are promising anticancer candidates to be exploited in additional studies.

Diagnosis and management of secondary adrenal crisis

Adrenal crisis (AC) is a life threatening acute adrenal insufficiency (AI) episode which can occur in patients with primary AI but also secondary AI (SAI), tertiary AI (TAI) and iatrogenic AI (IAI). In SAI, TAI and IAI, AC may develop when the HPA axis is unable to mount an adequate glucocorticoid response to severe stress due to pituitary or hypothalamic disruption. It manifests as an acute deterioration in multi-organ homeostasis that, if untreated, leads to shock and death. Despite the availability of effective preventive strategies, its prevalence is increasing in patients with SAI, TAI and IAI due to more frequent exogenous steroid administration, pituitary immune-related effects of immune checkpoint inhibitors and opioid use in pain management. The delayed diagnosis of acute AI which remains infrequently suspected increases the risk of AC. Its main precipitating factors are infections, emotional distress, surgery, cessation or reduction in GC doses, pituitary infarction or surgical cure of endogenous Cushing's syndrome. In patients not known previously to have SAI/TAI/IAI, recognition of its symptoms, signs, and biochemical abnormalities can be challenging and cause delay in proper diagnosis and therapy. Effective therapy of AC is rapid intravenous administration of hydrocortisone (initial bolus of 100 mg followed by 200 mg/24 h as continuous infusion or bolus of 50 mg every 6 h) and 0.9% saline. In diagnosed patients, preventive education in sick-day rules adjustment of glucocorticoid replacement and hydrocortisone parenteral self-administration must be performed repeatedly by trained health care providers. Strategies to improve the adequate preventive education in patients at risk for secondary AI should be promoted in collaboration with various medical specialist societies and patients support associations.

The potential impact of CYP and UGT drug-metabolizing enzymes on brain target site drug exposure

Drug metabolism is one of the critical determinants of drug disposition throughout the body. While traditionally associated with the liver, recent research has unveiled the presence and functional significance of drug-metabolizing enzymes (DMEs) within the brain. Specifically, cytochrome P-450 enzymes (CYPs) and UDP-glucuronosyltransferases (UGTs) enzymes have emerged as key players in drug biotransformation within the central nervous system (CNS). This comprehensive review explores the cellular and subcellular distribution of CYPs and UGTs within the CNS, emphasizing regional expression and contrasting profiles between the liver and brain, humans and rats. Moreover, we discuss the impact of species and sex differences on CYPs and UGTs within the CNS. This review also provides an overview of methodologies for identifying and quantifying enzyme activities in the brain. Additionally, we present factors influencing CYPs and UGTs activities in the brain, including genetic polymorphisms, physiological variables, pathophysiological conditions, and environmental factors. Examples of CYP- and UGT-mediated drug metabolism within the brain are presented at the end, illustrating the pivotal role of these enzymes in drug therapy and potential toxicity. In conclusion, this review enhances our understanding of drug metabolism's significance in the brain, with a specific focus on CYPs and UGTs. Insights into the expression, activity, and influential factors of these enzymes within the CNS have crucial implications for drug development, the design of safe drug treatment strategies, and the comprehension of drug actions within the CNS. To that end, CNS pharmacokinetic (PK) models can be improved to further advance drug development and personalized therapy.

Functional evaluation of CYP2C19 and CYP3A4 gene polymorphism on ibuprofen metabolism

AIM

Ibuprofen is the most commonly used analgesic. CYP polymorphisms are mainly responsible for the differences in drug metabolism among individuals. Variations in the ability of populations to metabolize ibuprofen can lead to drug exposure events. The aim of this study was to evaluate the effects of CYP2C19 and CYP3A4 polymorphisms on ibuprofen metabolism in a Chinese population.

METHODS

First, 31 CYP2C19 and 12 CYP3A4 microsomal enzymes were identified using an insect expression system. Then, variants were evaluated using a mature incubation system. Moreover, ibuprofen metabolite content was determined via ultra-performance liquid chromatography-tandem mass spectrometry analysis. Finally, kinetic parameters of CYP2C19 and CYP3A4 genotypes were determined via Michaelis-Menten curve fitting.

RESULTS

Most variants exhibited significantly altered intrinsic clearance compared to the wild type. In the CYP2C19 metabolic pathway, seven variants exhibited no significant alterations in intrinsic clearance (CLint), six variants exhibited significantly high CLint (121-291%), and the remaining 15 variants exhibited substantially reduced CLint (1-71%). In the CYP3A4 metabolic pathway, CYP3A4*30 was not detected in the metabolite content due to the absence of activity, and 10 variants exhibited significantly reduced CLint.

CONCLUSION

To the best of our knowledge, this is the first study to assess the kinetic characteristics of 31 CYP2C19 and 12 CYP3A4 genotypes on ibuprofen metabolism. However, further studies are needed on poor metabolizers as they are more susceptible to drug exposure. Our findings suggest that the kinetic characteristics in combination with artificial intelligence to predict the toxicity of ibuprofen and reduce any adverse drug reactions.

Therapeutic Drug Monitoring in Children and Adolescents: Findings on Fluoxetine from the TDM-VIGIL Trial

Fluoxetine is the recommended first-line antidepressant in many therapeutic guidelines for children and adolescents. However, little is known about the relationships between drug dose and serum level as well as the therapeutic serum reference range in this age group. Within a large naturalistic observational prospective multicenter clinical trial ("TDM-VIGIL"), a transdiagnostic sample of children and adolescents (n = 138; mean age, 15; range, 7-18 years; 24.6% males) was treated with fluoxetine (10-40 mg/day). Analyses of both the last timepoint and all timepoints (n = 292 observations), utilizing (multiple) linear regressions, linear mixed-effect models, and cumulative link (mixed) models, were used to test the associations between dose, serum concentration, outcome, and potential predictors. The receiver operating curve and first to third interquartile methods, respectively, were used to examine concentration cutoff and reference values for responders. A strong positive relationship was found between dose and serum concentration of fluoxetine and its metabolite. Higher body weight was associated with lower serum concentrations, and female sex was associated with lower therapeutic response. The preliminary reference ranges for the active moiety (fluoxetine+norfluoxetine) were 208-328 ng/mL (transdiagnostically) and 201.5-306 ng/mL (depression). Most patients showed marked (45.6%) or minimal (43.5%) improvements and reported no adverse effects (64.9%). This study demonstrated a clear linear dose-serum level relationship for fluoxetine in youth, with the identified reference range being within that established for adults.

Microbial Metabolites of 3-n-butylphthalide as Monoamine Oxidase A Inhibitors

Novel compounds with antidepressant activity via monoamine oxidase inhibition are being sought. Among these, derivatives of 3-n-butylphthalide, a neuroprotective lactone from Apiaceae plants, may be prominent candidates. This study aimed to obtain the oxidation products of 3-n-butylphthalide and screen them regarding their activity against the monoamine oxidase A (MAO-A) isoform. Such activity of these compounds has not been previously tested. To obtain the metabolites, we used fungi as biocatalysts because of their high oxidative capacity. Overall, 37 strains were used, among which Penicillium and Botrytis spp. were the most efficient, leading to the obtaining of three main products: 3-n-butyl-10-hydroxyphthalide, 3-n-butylphthalide-11-oic acid, and 3-n-butyl-11-hydroxyphthalide, with a total yield of 0.38-0.82 g per g of the substrate, depending on the biocatalyst used. The precursor-3-n-butylphthalide and abovementioned metabolites inhibited the MAO-A enzyme; the most active was the carboxylic acid derivative of the lactone with inhibitory constant (K_i) < 0.001 µmol/L. The in silico prediction of the drug-likeness of the metabolites matches the assumptions of Lipinski, Ghose, Veber, Egan, and Muegge. All the compounds are within the optimal range for the lipophilicity value, which is connected to adequate permeability and solubility.

Determination of CYP450 activities in diabetes mellitus rats by a UHPLC-MS/MS method

In this study, we investigated the effect of type 1 diabetes mellitus on the modulation of the activities of CYP450s in dynamics by a UHPLC-MS/MS method. The diabetic rat model was constructed by an intraperitoneal single injection of streptozotocin. Fasting blood glucose levels > 16.7 mmol/L were considered as diabetic. The rats were given a cocktail of four probe drugs (10 mg/kg phenacetin, 1 mg/kg tolbutamide, 10 mg/kg metoprolol, and 10 mg/kg midazolam) by oral administration for the pharmacokinetic study. Thereafter, the metabolic ratio (MR) of the metabolites to probe substrates were determined. The results indicated that two weeks after diabetes was induced, diabetes increased the MRs of acetaminophen/phenacetin (CYP1A2) and 4-hydroxyl tolbutamide/tolbutamide (CYP2C9); however, it decreased the MRs of α-hydroxy metoprolol/metoprolol (CYP2D6) and 1-hydroxy midazolam/midazolam (CYP3A4). Two months after diabetes was induced, diabetes increased the MRs of acetaminophen/phenacetin and 4-hydroxyl tolbutamide/tolbutamide. The MR of α-hydroxy metoprolol/metoprolol was decreased and the MR of 1-hydroxy midazolam/midazolam was increased but the difference was not significant. According to the results, CYP1A2 and CYP2C9 activities were enhanced in the diabetic rats. and CYP2D6 activity was inhibited in a short period of diabetes; however, the decrease in CYP2D6 activity was not significant in the long period. CYP3A4 activity was decreased in a short period of diabetes and increased in a long period of diabetes but was not significant in the two periods. This study suggests the activity change rule of the CYP450 enzyme system in diabetes mellitus, which can provide a reference for precise clinical medication.

Treating Hypopituitarism in the Over 65s: Review of Clinical Studies

The current increase of life expectancy is associated with the presence of endocrine diseases in the elderly. The management of hypopituitarism in this group of patients is a challenging task. A correct diagnosis, which represents an essential requisite for an appropriate medical treatment, can be difficult because of the physiological changes occurring in pituitary function with aging, which may lead to challenges in the interpretation of laboratory results. Furthermore, the treatment requires several careful considerations: the need to restore the hormonal physiology with replacement therapies must be balanced with the need to avoid the risks of the over-replacement, especially in the presence of concomitant cardiovascular and metabolic disease. Interactions with other drugs able to modify the absorption and/or the metabolism of hormonal replacement therapies should be considered, in particular for the treatment of hypoadrenalism and hypothyroidism. The most important challenges stem from the lack of specific studies focused on the management of hypopituitarism in older people.

Virtual screening of natural compounds as selective inhibitors of polo-like kinase-1 at C-terminal polo box and N-terminal catalytic domain

The over-expression of Polo-like kinase-1 (PLK1) is associated with cancer prognosis due to its pivotal role in cell proliferation. The N-terminal catalytic domain (NCD) and C-terminal polo box domain (PBD) of PLK1 are critical for the activity of the protein. Drugs that inhibit PLK1 by targeting these domains are on clinical trials, but so far, none has been approved by FDA. Thus, this study targets the two domains of PLK1 to identify compounds with inhibitory potential. Four validated e-pharmacophore models from NCD (PDB ID: 2OU7 and 4J52) and PBD (PDB ID: 5NEI and 5NN2) were used to screen over 26,000 natural compounds from NPASS database. Hits were identified after the well-fitted compounds were subjected to molecular docking study and ADME prediction. The pIC50 and electronic behaviour of the identified hits selectively targeting NCD and PBD of PLK1 were predicted via an externally validated QSAR model and quantum mechanics. The results showed that CAA180504, CAA197326, CAA74619, CAA328856 modulating PLK1 at NCD, and CBB130581, CBB230713, CBB206123, CBB12656 and CBB267117 modulating PLK1 at PBD had better molecular docking scores, pharmacokinetics and drug-like properties than NCD (volasertib) and PBD (purpurogallin) reference inhibitors. The compounds all had satisfactory inhibitory (pIC50) values which range from 6.187 to 7.157. The electronic behaviours of understudied compounds using HOMO/LUMO and global descriptive parameters revealed the atomic portion of the compounds prone to donating and accepting electrons. In conclusion, the hit compounds identified from the library of natural compounds are worthy of further experimental validation.Communicated by Ramaswamy H. Sarma.

Characterization of Novel Derivatives of MBQ-167, an inhibitor of the GTP-binding proteins Rac/Cdc42

Rac and Cdc42, are homologous GTPases that regulate cell migration, invasion, and cell cycle progression; thus, representing key targets for metastasis therapy. We previously reported on the efficacy of MBQ-167, which blocks both Rac1 and Cdc42 in breast cancer cells and mouse models of metastasis. To identify compounds with increased activity, a panel of MBQ-167 derivatives was synthesized, maintaining its 9-ethyl-3-(1H-1,2,3-triazol-1-yl)-9H-carbazole core. Similar to MBQ-167, MBQ-168 and EHop-097, inhibit activation of Rac and Rac1B splice variant and breast cancer cell viability, and induce apoptosis. MBQ-167 and MBQ-168 inhibit Rac and Cdc42 by interfering with guanine nucleotide binding, and MBQ-168 is a more effective inhibitor of PAK (1,2,3) activation. EHop-097 acts via a different mechanism by inhibiting the interaction of the guanine nucleotide exchange factor (GEF) Vav with Rac. MBQ-168 and EHop-097 inhibit metastatic breast cancer cell migration, and MBQ-168 promotes loss of cancer cell polarity to result in disorganization of the actin cytoskeleton and detachment from the substratum. In lung cancer cells, MBQ-168 is more effective than MBQ-167 or EHop-097 at reducing ruffle formation in response to EGF. Comparable to MBQ-167, MBQ-168 significantly inhibits HER2+ tumor growth and metastasis to lung, liver, and spleen. Both MBQ-167 and MBQ-168 inhibit the cytochrome P450 (CYP) enzymes 3A4, 2C9, and 2C19. However, MBQ-168 is ~10X less potent than MBQ-167 at inhibiting CYP3A4, thus demonstrating its utility in relevant combination therapies. In conclusion, the MBQ-167 derivatives MBQ-168 and EHop-097 are additional promising anti metastatic cancer compounds with similar and distinct mechanisms.

Human liver microsomes study on the inhibitory effect of plantainoside D on the activity of cytochrome P450 activity

BACKGROUND

Plantainoside D is widely existed in the herbs and possesses various pharmacological activities, making it possible to co-administrate with other herbs. Its effect on cytochrome P450 enzymes (P450) is a risk factor for inducing adverse drug-drug interactions. To assess the effect of plantainoside D on the activity of major P450 isoenzymes in human liver microsomes.

METHODS

The Cocktail method was conducted in human liver microsomes in the presence of probe substrates. The activity of P450 isoenzymes was evaluated by the production of corresponding metabolites. The concentration-dependent and time-dependent inhibition assays were performed in the presence of 0, 2.5, 5, 10, 25, 50, and 100 μM plantainoside D to characterize the inhibitory effect of plantainoside D.

RESULTS

Significant inhibition was observed in the activity of CYP1A2, 2D6, and 3A, which was concentration-dependent with the IC₅₀ values of 12.83, 8.39, and 14.66 μM, respectively. The non-competitive manner and competitive manner were observed in the CYP3A inhibition (Ki = 7.16 μM) and CYP1A2 (Ki = 6.26 μM) and 2D6 inhibition (Ki = 4.54 μM), respectively. Additionally, the inhibition of CYP3A was found to be time-dependent with the KI of 1.28 μM^-1 and K_inact of 0.039 min^-1.

CONCLUSIONS

Weak inhibitory effects of plantainoside D on the activity of CYP1A2, 2D6, and 3A were revealed in vitro, implying its potential of inducing interactions with CYP1A2-, 2D6-, and 3A-metabolized drugs. Although further in vivo validations are needed, the feasibility of the Cocktail method in evaluating P450 activity has been verified.

Toxicological Evaluation and In Silico Identification of Acetylcholinesterase Inhibitors in a Commercial Polyherbal Formulation (KWAPF01)

This study investigated the toxicological implications of a commercial polyherbal formulation, KWAPF01. Twenty-four Wistar rats were randomized into six groups of four animals per group. The animals in Group 1 were administered placebo and designated as control, while the rats in Groups 2 to 6 were administered 1000, 1500, 2000, 2500, and 3000 mg/kg bodyweight single oral dose of KWAPF01, respectively, and subsequently monitored for gross morphological and behavioural changes for 72 h. Piloerection, reduced motility, and tremor were observed in experimental groups, and the median lethal dose (LD50) of the extract was 2225.94 mg/kg bodyweight. The 11 compounds identified through HPLC analysis of the extract were docked against acetylcholinesterase (AChE), and the docking scores ranged from −5.3 to −10.8 kcal/mol, with catechol (−5.3 kcal/mol) and berberine (−10.8 kcal/mol) having the highest and lowest binding energies, respectively. Judging by the results, it could be inferred that some of the constituents of KWAPF01 have a direct impact on the nervous system and this is possibly elicited via the cholinergic system as it contains a nicotinic acetylcholine receptors agonist and potential inhibitors of AChE. Therefore, the use of KWAPF01 needs to be cautiously guided.

Seafood Paramyosins as Sources of Anti-Angiotensin-Converting-Enzyme and Anti-Dipeptidyl-Peptidase Peptides after Gastrointestinal Digestion: A Cheminformatic Investigation

Paramyosins, muscle proteins occurring exclusively in invertebrates, are abundant in seafoods. The potential of seafood paramyosins (SP) as sources of anti-angiotensin-converting-enzyme (ACE) and anti-dipeptidyl-peptidase (DPP-IV) peptides is underexplored. This in silico study investigated the release of anti-ACE and anti-DPP-IV peptides from SP after gastrointestinal (GI) digestion. We focused on SP of the common octopus, Humboldt squid, Japanese abalone, Japanese scallop, Mediterranean mussel, Pacific oyster, sea cucumber, and Whiteleg shrimp. SP protein sequences were digested on BIOPEP-UWM, followed by identification of known anti-ACE and anti-DPP-IV peptides liberated. Upon screening for high-GI-absorption, non-allergenicity, and non-toxicity, shortlisted peptides were analyzed via molecular docking and dynamic to elucidate mechanisms of interactions with ACE and DPP-IV. Potential novel anti-ACE and anti-DPP-IV peptides were predicted by SwissTargetPrediction. Physicochemical and pharmacokinetics of peptides were predicted with SwissADME. GI digestion liberated 2853 fragments from SP. This comprised 26 known anti-ACE and 53 anti-DPP-IV peptides exhibiting high-GI-absorption, non-allergenicity, and non-toxicity. SwissTargetPrediction predicted three putative anti-ACE (GIL, DL, AK) and one putative anti-DPP-IV (IAL) peptides. Molecular docking found most of the anti-ACE peptides may be non-competitive inhibitors, whereas all anti-DPP-IV peptides likely competitive inhibitors. Twenty-five nanoseconds molecular dynamics simulation suggests the stability of these screened peptides, including the three predicted anti-ACE and one predicted anti-DPP-IV peptides. Seven dipeptides resembling approved oral-bioavailable peptide drugs in physicochemical and pharmacokinetic properties were revealed: AY, CF, EF, TF, TY, VF, and VY. In conclusion, our study presented in silico evidence for SP being a promising source of bioavailable and safe anti-ACE and anti-DPP-IV peptides following GI digestions.

Drug-related problems identified during pharmaceutical care interventions in an intensive care unit at a tertiary university hospital

Introduction:

Drug-related problems could potentially worsen the clinical outcomes in critically ill patients. Critically ill patients are generally considered more vulnerable to harm from drug-related problems due to frequent medication-related events and complicated clinical courses. However, drug-related problems identified by on-ward clinical pharmacists in medical intensive care units in Thailand are not well reported. This study reports clinically relevant data with the description of identified problems, common causes of drug-related problems, and pharmacists’ interventions performed in real world, so that it may serve as an educational material for pharmacists who implement a pharmaceutical care and participate in medical intensive care units.

Methods:

A retrospective descriptive study was conducted at a tertiary university hospital in Bangkok, Thailand, from January 2015 to December 2020. The drug-related problems were categorized according to Cipolle et al.’s classification. The severity of drug-related problems in this study was rated by modifying the definition of The National Coordinating Council for Medication Error Reporting and Prevention Taxonomy of Medication Error to report harm from drug-related problem-related patient outcomes.

Results:

A total of 698 drug-related problems were detected in 374 critically ill patients. The prevalence of drug-related problems occurring in critically ill patients admitted to the medical intensive care unit was 73.9%. The most frequent drug-related problems were dosage too high (27.7%), ineffective drug (17.2%), need for additional drug therapy (15.3%), unnecessary drug therapy (14.6%), dosage too low (14.3%), adverse drug reaction (9.7%), and non-adherence (1.2%). The severity of drug-related problems in the medical intensive care unit was assessed as a drug-related problem with no harm (78.2%). Pharmacists’ interventions were advised according to drug-related problem identification to provide personalized pharmacotherapy optimization in critically ill patients.

Conclusion:

The most frequent drug-related problem identified during pharmaceutical care interventions in the medical intensive care unit at tertiary university hospital is dosage too high. The severity of drug-related problems is mostly determined as drug-related problems with no harm.

Potential Effects of Ibuprofen, Remdesivir and Omeprazole on Dexamethasone Metabolism in Control Sprague Dawley Male Rat Liver Microsomes (Drugs Often Used Together Alongside COVID-19 Treatment)

The role of individual cytochrome P450 (CYPs) responsible for the drug metabolism can be determined through their chemical inhibition. During the pandemic, dexamethasone and remdesivir with omeprazole were used for the treatment of COVID-19, while Ibuprofen was taken to treat the symptoms of fever and headache. This study aimed to examine the potency of ibuprofen remdesivir, and omeprazole as inhibitors of cytochrome P450s using rat liver microsomes in vitro. Dexamethasone a corticosteroid, sometimes used to reduce the body’s immune response in the treatment of COVID-19, was used as a probe substrate and the three inhibitors were added to the incubation system at different concentrations and analysed by a validated High Performance Liquid Chromatography (HPLC) method. The CYP3A2 isoenzyme is responsible for dexamethasone metabolism in vitro. The results showed that ibuprofen acts as a non-competitive inhibitor for CYP3A2 activity with K_i = 224.981 ± 1.854 µM and IC₅₀ = 230.552 ± 2.020 µM, although remdesivir showed a mixed inhibition pattern with a K_i = 22.504 ± 0.008 µM and IC₅₀ = 45.007 ± 0.016 µM. Additionally, omeprazole uncompetitively inhibits dexamethasone metabolism by the CYP3A2 enzyme activity with a K_i = 39.175 ± 0.230 µM and IC₅₀ = 78.351 ± 0.460 µM. These results suggest that the tested inhibitors would not exert a significant effect on the CYP3A2 isoenzyme responsible for the co-administered dexamethasone drug’s metabolism in vivo.

Changes in CYP3A4 Enzyme Expression and Biochemical Markers Under Acute Hypoxia Affect the Pharmacokinetics of Sildenafil

To investigate the effects of pathological, physiological, biochemical and metabolic enzymes CYP3A4 on the pharmacokinetics of sildenafil under acute hypoxia, rats were randomly divided into the plain group (50 m above sea level), acute plateau group 1 (2300 m above sea level), and acute plateau group 2 (4300 m above sea level), and blood samples and liver tissues were collected. Our results showed that the blood gas, physiological and biochemical indexes of rats changed under acute hypoxia, and the protein expression of CYP3A4 enzyme decreased. The process of absorption, distribution, metabolism and excretion of sildenafil in rats has changed. Compared with the P group, the area under the drug-time curve and the average resident in the H2 group increased to 213.32 and 72.34%, respectively. The half-life and peak concentration increased by 44.27 and 133.67%, respectively. The clearance rate and apparent distribution volume decreased to 69.13 and 46.75%, respectively. There were no statistical differences in the pharmacokinetic parameters between the P group and the H1 group. In conclusion, the pharmacokinetic changes of sildenafil have a multi-factor regulation mechanism, and changes in blood gas, pathology, and biochemical indicators and metabolic enzymes affect the absorption, distribution, excretion, and metabolism of sildenafil, respectively. This study provides experimental evidence and new ideas for the rational use of sildenafil under acute hypoxic conditions.

The Effects of AT-533 and AT-533 gel on Liver Cytochrome P450 Enzymes in Rats

BACKGROUND AND OBJECTIVES

AT-533 is a novel heat shock protein 90 inhibitor, which exhibits various biological activities in vitro and in vivo. Cytochrome P450 (CYP) enzymes in the liver are involved in the biotransformation of drugs and considered to be essential indicators of liver toxicity. The aim of this study was to assess the effect of AT-533, either as active pharmaceutical ingredient or in gel form, on liver CYP enzymes.

METHODS

The effect of AT-533 or AT-533 gel on rat liver cytochrome P450 enzymes, including CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, was analyzed using LC-MS/MS.

RESULTS

AT-533 and AT-533 gel did not significantly increase or reduce the enzymatic activity of CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 at any treatment dose.

CONCLUSIONS

AT-533 and AT-533 gel did not have any effect on CYP activity and may be considered safe for external use in gel form, as an alternative to conventional treatment.

In vitro interaction of potential antiviral TMPRSS2 inhibitors with human serum albumin and cytochrome P 450 isoenzymes

The interactions of four sulfonylated Phe(3-Am)-derived inhibitors (MI-432, MI-463, MI-482 and MI-1900) of type II transmembrane serine proteases (TTSP) such as transmembrane protease serine 2 (TMPRSS2) were examined with serum albumin and cytochrome P450 (CYP) isoenzymes. Complex formation with albumin was investigated using fluorescence spectroscopy. Furthermore, microsomal hepatic CYP1A2, 2C9, 2C19 and 3A4 activities in presence of these inhibitors were determined using fluorometric assays. The inhibitory effects of these compounds on human recombinant CYP3A4 enzyme were also examined. In addition, microsomal stability assays (60-min long) were performed using an UPLC-MS/MS method to determine depletion percentage values of each compound. The inhibitors showed no or only weak interactions with albumin, and did not inhibit CYP1A2, 2C9 and 2C19. However, the compounds tested proved to be potent inhibitors of CYP3A4 in both assays performed. Within one hour, 20%, 12%, 14% and 25% of inhibitors MI-432, MI-463, MI-482 and MI-1900, respectively, were degraded. As essential host cell factor for the replication of the pandemic SARS-CoV-2, the TTSP TMPRSS2 emerged as an important target in drug design. Our study provides further preclinical data on the characterization of this type of inhibitors for numerous trypsin-like serine proteases.

Phytochemical Screening, In Vitro and In Silico Studies of Volatile Compounds from Petroselinum crispum (Mill) Leaves Grown in Saudi Arabia

The herbal plant Petroselinum crispum (P. crispum) (Mill) is commonly available around the world. In this study, the leaves of the herbal plant P. crispum were collected from the central region of Al-Kharj, Saudi Arabia, to explore their in vitro pharmacological activity. Essential oil from the leaves of P. crispum was isolated using the hydrodistillation method. The composition of P. crispum essential oil (PCEO) was determined using Gas chromatography-mass spectrometry (GC-MS). A total of 67 components were identified, representing approximately 96.02% of the total volatile composition. Myristicin was identified as the principal constituent (41.45%). The in vitro biological activity was assessed to evaluate the antioxidant, antimicrobial, and anti-inflammatory potential of PCEO. PCEO showed the highest antimicrobial activity against Candida albicans and Staphylococcus aureus among all the evaluated microbial species. In vitro anti-inflammatory evaluation using albumin and trypsin assays showed the excellent anti-inflammatory potential of PCEO compared to the standard drugs. An in silico study of the primary PCEO compound was conducted using online tools such as PASS, Swiss ADME, and Molecular docking. In silico PASS prediction results supported our in vitro findings. Swiss ADME revealed the drug likeness and safety properties of the major metabolites present in PCEO. Molecular docking results were obtained by studying the interaction of Myristicin with an antifungal (PDB: 1IYL and 3LD6), antibacterial (PDB: 1AJ6 and 1JIJ), antioxidant (PDB: 3NM8 and 1HD2), and anti-inflammatory (3N8Y and 3LN1) receptors supported the in vitro results. Therefore, PCEO or Myristicin might be valuable for developing anti-inflammatory and antimicrobial drugs.

Role of P34S, G169R, R296C, and S486T Substitutions in Ligand Access and Catalysis for Cytochrome P450 2D6 Allelic Variants CYP2D6*14A and CYP2D6*14B

BACKGROUND

Genetic polymorphism of cytochrome P450 (CYP) contributes to variability in drug metabolism, clearance, and response. This study aimed to investigate the functional and molecular basis for altered ligand binding and catalysis in CYP2D6*14A and CYP2D6*14B, two unique alleles common in the Asian population.

METHODS

CYP proteins expressed in Escherichia coli were studied using the substrate 3-cyano-7- ethoxycoumarin (CEC) and inhibitor probes (quinidine, fluoxetine, paroxetine, terbinafine) in the enzyme assay. Computer modelling was additionally used to create three-dimensional structures of the CYP2D6*14 variants.

RESULTS

Kinetics data indicated significantly reduced intrinsic clearance in CYP2D6*14 variants, suggesting that P34S, G169R, R296C, and S486T substitutions worked cooperatively to alter the conformation of the active site that negatively impacted the deethylase activity of CYP2D6. For the inhibition studies, IC50 values decreased in quinidine, paroxetine, and terbinafine but increased in fluoxetine, suggesting a varied ligand-specific susceptibility to inhibition. Molecular docking further demonstrated the role of P34S and R296C in altering access channel dimensions, thereby affecting ligand access and binding and subsequently resulting in varied inhibition potencies.

CONCLUSION

In summary, the differential selectivity of CYP2D6*14 variants for the ligands (substrate and inhibitor) was governed by the alteration of the active site and access channel architecture induced by the natural mutations found in the alleles.

Antibacterial, Docking, DFT and ADMET Properties Evaluation of Chalcone-Sulfonamide Derivatives Prepared Using ZnO Nanoparticle Catalysis

INTRODUCTION

In the present work, two novel compounds were synthesized using zinc oxide nanoparticles through green synthesis protocol. The zinc oxide nanoparticles catalyzed reactions were afforded good to excellent yields of the target compounds 76.3-98.6%.

METHODOLOGY

The synthesized compounds were characterized by UV-Vis, IR and NMR. The antibacterial activity of the synthesized compounds was screened against two Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Salmonella typhimurium).

RESULTS AND DISCUSSION

The synthesized compounds displayed potent activity against the bacterial strains. Among them, compound 8 showed strong activity against Bacillus cereus relative to the standard drug. On the other hand, compound 9 exhibited strong activity against Escherichia coli. The molecular docking study of the synthesized compounds was conducted to investigate their binding pattern with DNA gyrase and E. coli dihydropteroate synthase and all of them were found to have minimum binding energy ranging from -6.0 to -7.3 kcal/mol, and the best result achieved with compound 8 and 9.

CONCLUSION

The findings of the in vitro antibacterial and molecular docking analysis demonstrated that the synthesized compounds have potential of antibacterial activity and can be further optimized to serve as a lead compound.

Plumbagin and Plumbago indica Differentially Modulated Cytochrome P450 and Transporter Profiles in BeWo and HepG2 Cells

&lt;b&gt;Background and Objective:&lt;/b&gt; The medicinal herb &lt;i&gt;Plumbago indica&lt;/i&gt; (PI) and its major constituent plumbagin have reported pharmacological properties but there is a lack of information about their herb-drug interactions. The effects of methanolic (PI-MeOH) and ethanolic (PI-EtOH) crude extracts of PI and plumbagin on the expression of cytochrome P450s (&lt;i&gt;CYP1A2&lt;/i&gt;, &lt;i&gt;CYP2E1&lt;/i&gt; and &lt;i&gt;CYP3A4&lt;/i&gt;) and transporters (&lt;i&gt;ABCC1&lt;/i&gt;, &lt;i&gt;ABCG2&lt;/i&gt; and &lt;i&gt;SLC22A11&lt;/i&gt;) were investigated in BeWo and HepG2 cells. &lt;b&gt;Materials and Methods:&lt;/b&gt; BeWo or HepG2 cells were treated with 0.5-5 μM plumbagin or 25-500 μg mL&lt;sup&gt;1&lt;/sup&gt; of PI-MeOH or PI-EtOH for 24 hrs. Total RNA was extracted and mRNA expression of CYPs and transporters were determined using RT-qPCR. &lt;b&gt;Results:&lt;/b&gt; PI and plumbagin affected mRNA expression differently in the two tested cell types. In BeWo cells, all concentrations of PI-MeOH induced &lt;i&gt;CYP2E1&lt;/i&gt;, 100 and 500 μg Ml&lt;sup&gt;1&lt;/sup&gt; PI-MeOH and PI-EtOH up-regulated &lt;i&gt;CYP1A2&lt;/i&gt;, &lt;i&gt;CYP3A4 &lt;/i&gt;and &lt;i&gt;ABCG2 &lt;/i&gt;and 500 μg mL&lt;sup&gt;1&lt;/sup&gt; PI-EtOH induced &lt;i&gt;ABCG2&lt;/i&gt; expression. Plumbagin suppressed &lt;i&gt;CYP1A2&lt;/i&gt; and induced &lt;i&gt;SLC22A11 &lt;/i&gt;expression at the highest concentration, 5 μM. In HepG2 cells, 5 μM plumbagin and 500 μg Ml&lt;sup&gt;1&lt;/sup&gt; PI-EtOH suppressed &lt;i&gt;CYP3A4 &lt;/i&gt;expression and 500 μg mL&lt;sup&gt;1&lt;/sup&gt; PI-MeOH and PI-EtOH up-regulated &lt;i&gt;CYP1A2&lt;/i&gt; and &lt;i&gt;CYP2E1 &lt;/i&gt;expression. &lt;i&gt;ABCC1&lt;/i&gt; expression was induced by all treatments while &lt;i&gt;ABCG2&lt;/i&gt; and &lt;i&gt;SLC22A11 &lt;/i&gt;were induced only by 500 μg mL&lt;sup&gt;1&lt;/sup&gt; PI-MeOH and PI-EtOH. &lt;b&gt;Conclusion:&lt;/b&gt; The use of PI or plumbagin supplements in large quantities or for long periods should be carefully considered due to the risk of herbal drug interactions via modulated expression of CYPs and transporters.

The influence of excessive consumption of liquorice on phenprocoumon (Marcumar®): a case report

Here, the case of a 92-year-old female patient, who was diagnosed with atrial fibrillation and treated with phenprocoumon (Marcumar®), is reported. Pre-existing comorbidities were arterial hypertension, coronary heart disease, diabetes mellitus type 2, mild senile dementia and renal insufficiency. Despite treatment with phenprocoumon (Marcumar®), the patient experienced an ischaemic stroke. Her measured international normalized ratio (INR)-values during the months before the stroke were within the therapeutic range of 2–3, then suddenly decreased to 1.25. A retrospective inquiry failed to identify any significant changes in behaviour or therapy adherence, other than the consumption of 1.5 kg (3.3 lb) of hard-boiled candy liquorice in the days leading up to the stroke. The sudden decrease in INR-values may be explained by the influence of liquorice and its compounds on the pharmacokinetics of phenprocoumon (Marcumar®). In this context, the most important factors are the susceptibility of vitamin K antagonists to nutrition or metabolic irregularities, the influence of liquorice on the function of isoenzymes of the cytochrome P450 family that may lead to reduced bioavailability of phenprocoumon, and the influence of liquorice on peroxisome proliferator-activated receptor alpha transactivation.

Effect of GLPG1205, a GPR84 Modulator, on CYP2C9, CYP2C19, and CYP1A2 Enzymes: In Vitro and Phase 1 Studies

GLPG1205 is a novel agent being investigated for the treatment of idiopathic pulmonary fibrosis. GLPG1205 may be concomitantly administered with pirfenidone in future clinical development; therefore, the potential for GLPG1205 to interact with enzymes involved in the metabolism of pirfenidone (cytochrome P450 [CYP] 1A2, CYP2C9, 2C19) was evaluated. In vitro experiments indicated weak inhibition of CYP1A2 and moderate but reversible inhibition of CYP2C9 and CYP2C19 by GLPG1205. A phase 1 randomized, double-blind crossover study in 14 healthy males (NCT02623296) evaluated the effect of GLPG1205 100 mg or placebo (once daily for 12 days) on the single-dose pharmacokinetics of a cocktail of CYP1A2, CYP2C9, and CYP2C19 substrates (coadministered on day 13). GLPG1205 had no effect on the exposure of CYP2C9 and CYP1A2 substrates or metabolites; however, a trend toward increased omeprazole (CYP2C19 substrate) exposure was observed. Although considered not clinically relevant, GLPG1205 increased the elimination rate of 5-hydroxyomeprazole (CYP2C19 metabolite) 1.16-fold versus placebo. GLPG1205 had no effect on the elimination of all other substrates or metabolites. GLPG1205 had a favorable safety and tolerability profile. In conclusion, GLPG1205 100 mg once daily does not interact with CYP2C9, CYP2C19, or CYP1A2 to a clinically relevant extent and may be administered concomitantly with drugs metabolized by these enzymes.

Classification of drugs for evaluating drug interaction in drug development and clinical management

During new drug development, clinical drug interaction studies are carried out in accordance with the mechanism of potential drug interactions evaluated by in vitro studies. The obtained information should be provided efficiently to medical experts through package inserts and various information materials after the drug's launch. A recently updated Japanese guideline presents general procedures that are considered scientifically valid at the present moment. In this review, we aim to highlight the viewpoints of the Japanese guideline and enumerate drugs that were involved or are anticipated to be involved in evident pharmacokinetic drug interactions and classify them by their clearance pathway and potential intensity based on systematic reviews of the literature. The classification would be informative for designing clinical studies during the development stage, and the appropriate management of drug interactions in clinical practice.

Molecular docking studies of Nigella sativa L and Curcuma xanthorrhiza Roxb secondary metabolites against histamine N-methyltransferase with their ADMET prediction

OBJECTIVES

Histamine N-methyltransferase (HNMT) is an enzyme that plays a crucial role in the inactivation of histamine in central nervous system, kidneys and bronchi. Inhibition of HNMT is known to have a potential role in treating attention-deficit hyperactivity disorder, memory impairment, mental illness and neurodegenerative illnesses. Therefore, to find potential compounds that could be developed as novel HNMT inhibitors, this study conducted an in silico study of the secondary metabolites of Nigella sativa L and Curcuma xanthorrhiza Roxb.

METHODS

In this study, we conducted a molecular docking study of 36 secondary metabolites of N. sativa L and 26 secondary metabolites of C. xanthorrhiza Roxb using an in silico approach targeting HNMT protein (PDB ID: 2AOT) using AutoDockVina software. The prediction of ADMET characteristics was done using the pkCSM Online Tool.

RESULTS

This study obtained one metabolite from N. sativa L (longifolene) and seven metabolites from C. xanthorrhiza Roxb {(+)-beta-atlantone, humulene epoxide, (-)-beta-curcumene, (E)-caryophyllene, germacrone, (R)-(-)-xanthorrhizol, and (-)-beta-caryophyllene epoxide} which were predicted to have potential to be developed as HNMT inhibitors.

CONCLUSIONS

This study found several secondary metabolites of N. sativa L and C. xanthorrhiza Roxb which had activity as HNMT inhibitors. This research can likewise be utilized as a basis for further research, both in vitro, in vivo, and clinical trials related to the development of secondary metabolites from N. sativa L and C. xanthorrhiza Roxb as novel HNMT inhibitor compounds.

Cheminformatic Profiling and Hit Prioritization of Natural Products with Activities against Methicillin-Resistant Staphylococcus aureus (MRSA)

Several natural products (NPs) have displayed varying in vitro activities against methicillin-resistant Staphylococcus aureus (MRSA). However, few of these compounds have not been developed into potential antimicrobial drug candidates. This may be due to the high cost and tedious and time-consuming process of conducting the necessary preclinical tests on these compounds. In this study, cheminformatic profiling was performed on 111 anti-MRSA NPs (AMNPs), using a few orally administered conventional drugs for MRSA (CDs) as reference, to identify compounds with prospects to become drug candidates. This was followed by prioritizing these hits and identifying the liabilities among the AMNPs for possible optimization. Cheminformatic profiling revealed that most of the AMNPs were within the required drug-like region of the investigated properties. For example, more than 76% of the AMNPs showed compliance with the Lipinski, Veber, and Egan predictive rules for oral absorption and permeability. About 34% of the AMNPs showed the prospect to penetrate the blood–brain barrier (BBB), an advantage over the CDs, which are generally non-permeant of BBB. The analysis of toxicity revealed that 59% of the AMNPs might have negligible or no toxicity risks. Structure–activity relationship (SAR) analysis revealed chemical groups that may be determinants of the reported bioactivity of the compounds. A hit prioritization strategy using a novel “desirability scoring function” was able to identify AMNPs with the desired drug-likeness. Hit optimization strategies implemented on AMNPs with poor desirability scores led to the design of two compounds with improved desirability scores.

A review on diverse heterocyclic compounds as the privileged scaffolds in non-steroidal aromatase inhibitors

Breast cancer, emerging malignancy is common among women due to overexpression of estrogen. Estrogens are biosynthesized from androgens by aromatase, a cytochrome P450 enzyme complex, and play a pivotal role in stimulating cell proliferation. Therefore, deprivation of estrogen by blocking aromatase is considered as the effective way for the inhibition and treatment of breast cancer. In recent years, various non-steroidal heterocyclic functionalities have been extensively developed and studied for their aromatase inhibition activity. This review provides information about the structural-activity relationship of heterocycles (Type II) towards aromatase. This aids the medicinal chemist around the significance of different heterocyclic moieties and helps to design potent aromatase inhibitors.

GLPG1205, a GPR84 Modulator: Safety, Pharmacokinetics, and Pharmacodynamics in Healthy Subjects

GLPG1205 is a modulator of GPR84, a G‐protein–coupled receptor reported to be associated with several diseases. Safety, tolerability, pharmacokinetics, and pharmacodynamics of GLPG1205 in healthy subjects were evaluated in 2 randomized, double‐blind, placebo‐controlled, single‐site, phase 1 studies. In study 1, 16 (aged 21‐48 years) and 24 (24‐50 years) healthy men received single doses of GLPG1205 10 to 800 mg, and GLPG1205 50, 100, or 200 mg once daily for 14 days, respectively, or placebo. Study 2 evaluated the effect of aging on GLPG1205 pharmacokinetics: 24 healthy men (aged 37–83 years), weight‐matched into 3 age cohorts (65‐74, ≥75, and 18‐50 years), received GLPG1205 50 mg or placebo once daily for 14 days; an open‐label part of this study evaluated a GLPG1205 250‐mg loading dose followed by 50 mg once daily for 13 days in 8 healthy men (aged 68‐74 years). Single (up to 800 mg) and multiple (maximum tolerated dose 100 mg once daily) GLPG1205 doses had favorable safety and tolerability profiles. After single administration of GLPG1205, median time to occurrence of maximum observed plasma concentration and arithmetic mean apparent terminal half‐life ranged from 2.0 to 4.0 and from 30.1 to 140 hours, respectively. Age did not affect GLPG1205 exposure. GPR84 receptor occupancy with GLPG1205 vs placebo confirmed target engagement. These results support further clinical development of GLPG1205.

Role of Endocrine-Disrupting Chemicals in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: A Comprehensive Review

Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disorder, affecting around 25% of the population worldwide. It is a complex disease spectrum, closely linked with other conditions such as obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, which may increase liver-related mortality. In light of this, numerous efforts have been carried out in recent years in order to clarify its pathogenesis and create new prevention strategies. Currently, the essential role of environmental pollutants in NAFLD development is recognized. Particularly, endocrine-disrupting chemicals (EDCs) have a notable influence. EDCs can be classified as natural (phytoestrogens, genistein, and coumestrol) or synthetic, and the latter ones can be further subdivided into industrial (dioxins, polychlorinated biphenyls, and alkylphenols), agricultural (pesticides, insecticides, herbicides, and fungicides), residential (phthalates, polybrominated biphenyls, and bisphenol A), and pharmaceutical (parabens). Several experimental models have proposed a mechanism involving this group of substances with the disruption of hepatic metabolism, which promotes NAFLD. These include an imbalance between lipid influx/efflux in the liver, mitochondrial dysfunction, liver inflammation, and epigenetic reprogramming. It can be concluded that exposure to EDCs might play a crucial role in NAFLD initiation and evolution. However, further investigations supporting these effects in humans are required.

Utilizing Tiny-TIM to Assess the Effect of Acid-Reducing Agents on the Absorption of Orally Administered Drugs

Acid-reducing agents (ARAs) are the most commonly used medicines to treat patients with gastric acid-related disorders. ARA administration results in an elevation of intragastric pH and eases symptoms such as acid reflux. However, this effect could also lead to a reduction in the absorption of some co-administered oral medications (i.e. weakly basic drugs) by decreasing their gastric solubility. This in turn can result in a significant reduction of the efficacy of the co-administered oral medications. In order to address this problem, substantial efforts in translational modeling and the development of predictive in-vitro assays to better forecast the effect of ARA on oral absorption are conducted in the pharmaceutical industry. Despite these efforts, it remains challenging to predict the impact of ARAs on co-administered drugs. In this study, we evaluated the utility of Triskelion's Gastro-Intestinal Model (Tiny-TIM) in predicting ARA effect on twelve model drugs whose in-vivo data are available. The Tiny-TIM prediction of the ARA effect matched the observed effect of ARA co-administration in humans for the 12 model compounds. In summary, Tiny-TIM is a very reliable and promising GI model to successfully predict the nature of DDI when ARAs are co-administered with the drug of interest.

In Silico Identification of Multi-target Anti-SARS-CoV-2 Peptides from Quinoa Seed Proteins

Peptides are promising antagonists against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). To expedite drug discovery, a computational approach is widely employed for the initial screening of anti-SARS-CoV-2 candidates. This study aimed to investigate the potential of peptides from quinoa seed proteins as multi-target antagonists against SARS-CoV-2 spike glycoprotein receptor-binding domain, main protease, and papain-like protease. Five quinoa proteins were hydrolyzed in silico by papain and subtilisin. Among the 1465 peptides generated, seven could interact stably with the key binding residues and catalytic residues of the viral targets, mainly via hydrogen bonds and hydrophobic interactions. The seven peptides were comparable or superior to previously reported anti-SARS-CoV-2 peptides based on docking scores. Key residues in the seven peptides contributing to binding to viral targets were determined by computational alanine scanning. The seven peptides were predicted in silico to be non-toxic and non-allergenic. The peptides ranged between 546.66 and 3974.87 g/mol in molecular mass, besides exhibiting basic and cationic properties (isoelectric points: 8.26-12.10; net charges: 0.1-4.0). Among the seven peptides, VEDKGMMHQQRMMEKAMNIPRMCGTMQRKCRMS was found to bind the largest number of key residues on the targets. In conclusion, seven putative non-toxic, non-allergenic, multi-target anti-SARS-CoV-2 peptides were identified from quinoa seed proteins. The in vitro and in vivo efficacies of the seven peptides against SARS-CoV-2 deserve attention in future bench-top testing.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10989-021-10214-y.

Mechanism of idiosyncratic drug induced liver injury (DILI): unresolved basic issues

Clinical features of idiosyncratic drug induced liver injury (DILI) are well described in cases that have been assessed for causality using the Roussel Uclaf Causality Assessment Method (RUCAM), but our understanding of the mechanistic steps leading to injury is fragmentary. The difficulties describing mechanistic events can be traced back to the lack of an animal model of experimental idiosyncratic DILI that can mimic the genetic requirements of human idiosyncratic DILI. However, immune tolerance plays a dominant role in the immune response of the liver, and impairment of immune tolerance with immune checkpoint inhibitors increases DILI in both humans and animals. This may provide one method to study the individual steps involved. In general. the human DILI liver is a secret keeper providing little insight into what occurs in the diseased organ. Sufficient evidence exists that most idiosyncratic cases are mediated by the adaptive immune system, which depends on stimulation of the innate immune system, but the triggering factors are unknown. It is attractive to hypothesize that the gut microbiome plays a role; however, it is very difficult to study. Similarly, exosomes are likely to play an important role in communication between hepatic cells and the immune system, but there is a lack of data on blood exosomes in affected patients. Reactive metabolites are likely to play an important role. This is supported by the current analysis, which revealed an association between metabolism by cytochrome P450 and drugs most commonly involved in causing idiosyncratic DILI with causality verified by RUCAM. Circumstantial evidence suggests that reactive oxygen species (ROS) generated by cytochrome P450 could be responsible for the initial steps of injury, but details are unknown. In conclusion, most of the mechanistic steps leading to idiosyncratic DILI remain unclear.

Cytochrome P450 2C19 enzyme, Cytochrome P450 2C9 enzyme, and Cytochrome P450 2D6 enzyme allelic variants and its possible effect on drug metabolism: A retrospective study

ABSTRACT

The objective of the present study was to assess the allelic variations of Cytochrome P450 (CYP) enzymes Cytochrome P450 2C19 (CYP2C19), Cytochrome P450 2C9 (CYP2C9), and Cytochrome P450 2D6 (CYP2D6) as they play a major role in drug metabolism. The interindividual genetic variabilities of these enzymes can account for different responsiveness as well as concentration fluctuations for a particular drug.During the period of 2017 to 2018 a total of 54 patients have received pharmacogenetic testing at the Department of Genetics and Molecular Medicine at Kaunas Clinics. According to the genotype-metabolic phenotypes of CYP2C19, CYP2D6, CYP2C9 enzymes patients were classified according to the guidelines by Clinical Pharmacogenetics Implementation Consortium (CPIC): normal metabolizers (NMs), intermediate metabolizers (IMs), rapid metabolizers (RMs), ultrarapid metabolizers (UMs), and poor metabolizers (PMs).CYP2C19 enzyme allelic distribution: 18 patients (33.33%) with ∗1/∗1 genotype were NMs; 14 patients (25.93%) with ∗1/∗2; ∗2/∗17 genotypes were classified as IMs; 15 patients (27.78%) possessed ∗1/∗17 genotype and were RMs; 4 patients (7.4%) had ∗17/∗17 genotype with increased enzyme activity compared with RMs, were classified as UMs; 3 patients (5.56%) had ∗2/∗2 genotype and were marked as PMs. CYP2D6 enzyme allelic distribution: 26 patients (48.148%) contained ∗1/∗1,∗2/∗2,∗1/∗2,∗1/∗41,∗2/∗41 genotypes with normal enzymatic function so were accounted as NMs; 21 patients (38.89%) with ∗1/∗5, ∗2/∗4, ∗10/∗41, ∗1/∗4, ∗1/∗3, ∗2/∗5, ∗2/∗4, ∗2/∗6 genotypes were accounted as IMs; 2 patients (3.7%) possessed ∗2XN genotype and were accounted as UMs and 5 patients (9.26%) possessed ∗4/∗5,∗4/∗10,∗4/∗9,∗4/∗41 genotypes and had non-functional enzymatic activity so were accounted as PMs; CYP2C9 enzyme allelic distribution: 44 patients (81.48%) with∗1/∗1 genotype were NMs; 10 patients (18.52%) with ∗1/∗2;∗1/∗3 genotypes were IMs.The results of our study indicate that deviations from the normal enzymatic activity is common amongst Lithuanian people and combinatory genotyping of CYP2D6, CYP2C9, and CYP2C19 has to be promoted as an advanced method because of most commonly prescribed medicines like analgesics, antihypertensive, antidepressants are metabolized by multiple pathways involving enzymes in the CYP450 family.

Biological roles of cytochrome P450 1A1, 1A2, and 1B1 enzymes

Human cytochrome P450 enzymes (CYPs) play a critical role in various biological processes and human diseases. CYP1 family members, including CYP1A1, CYP1A2, and CYP1B1, are induced by aryl hydrocarbon receptors (AhRs). The binding of ligands such as polycyclic aromatic hydrocarbons activates the AhRs, which are involved in the metabolism (including oxidation) of various endogenous or exogenous substrates. The ligands that induce CYP1 expression are reported to be carcinogenic xenobiotics. Hence, CYP1 enzymes are correlated with the pathogenesis of cancers. Various endogenous substrates are involved in the metabolism of steroid hormones, eicosanoids, and other biological molecules that mediate the pathogenesis of several human diseases. Additionally, CYP1s metabolize and activate/inactivate therapeutic drugs, especially, anti-cancer agents. As the metabolism of drugs determines their therapeutic efficacy, CYP1s can determine the susceptibility of patients to some drugs. Thus, understanding the role of CYP1s in diseases and establishing novel and efficient therapeutic strategies based on CYP1s have piqued the interest of the scientific community.

Olanzapine-Associated Rhabdomyolysis: A Case Report

This paper presents the case of a 20-year-old patient with a suspected diagnosis of paranoid schizophrenia. He was prescribed oral olanzapine at a dose of 10 mg per day, and the treatment was associated with rhabdomyolysis (serum creatine kinase = 9,725 U/L on day four of the therapy). On suspicion of its contribution to rhabdomyolysis, olanzapine was immediately withdrawn. Pharmacogenetic testing demonstrated that the patient’s CYP2D6 genotype was *4/*4 (1846G>A, rs3892097). Based on these results, the patient was switched to trifluoperazine, a medication that is not metabolized by the CYP2D6 isoenzyme. Subsequently, the patient recovered well and was discharged without any nephrological sequelae. The presented case demonstrates that pharmacogenetic‐guided personalization of treatment may allow selecting the best medication and determining the right dosage, resulting in the reduced risk of adverse drug reactions and pharmacoresistance.

Clinical Unmet Needs in the Treatment of Adrenal Crisis: Importance of the Patient's Perspective

Adrenal crisis is the most severe manifestation of adrenal insufficiency (AI), but AI can present with variable signs and symptoms of gradual severity. Despite current hormone replacement strategies, adrenal crisis is still one of the leading causes of mortality in AI patients. Although underlying factors explaining differences in interindividual susceptibility are not completely understood, several subgroups are particularly vulnerable to adrenal crises, such as patients with primary AI, and patients treated for Cushing's syndrome. Currently, the health care professional faces several challenges in the care for AI patients, including the lack of reliable biomarkers measuring tissue cortisol concentrations, absence of a universally used definition for adrenal crisis, and lack of clinical tools to identify individual patients at increased risk. Also from the patient's perspective, there are a number of steps to be taken in order to increase and evaluate self-management skills and, finally, improve health-related quality of life (HR-QoL). In this respect, the fact that inadequate handling of AI patients during stressful situations is a direct consequence of not remembering how to act due to severe weakness and cognitive dysfunction in the context of the adrenal crisis is quite underexposed. In this narrative review, we give an overview of different clinical aspects of adrenal crisis, and discuss challenges and unmet needs in the management of AI and the adrenal crisis from both the doctor's and patient's perspective. For the latter, we use original focus group data. Integration of doctor's and patient's perspectives is key for successful improvement of HR-QoL in patients with AI.

[Influence of CYP3A4, CYP3A5, and NR3C1 genes polymorphism on the effectiveness of glucocorticoid therapy in patients with endocrine ophthalmopathy]

For more than 60 years, glucocorticoid therapy has been practically the only method for treating patients with endocrine ophthalmopathy - non-specific autoimmune inflammation of the soft tissues of the orbit. Steroid-resistant forms of this disease are known to exist. The reasons for the formation of glucocorticoid resistance are not fully understood yet.

PURPOSE

To study the possibilities of pharmacogenetic testing for the polymorphism of the glucocorticoid receptor gene NR3C1 and cytochrome P450 in predicting the effectiveness of glucocorticoid therapy in patients with edematous exophthalmos - one of the clinical forms of endocrine ophthalmopathy.

MATERIAL AND METHODS

The results of glucocorticoid therapy were analyzed in 75 patients with different clinical forms of endocrine ophthalmopathy aged 27 to 84 years. All patients underwent standard ophthalmological examination, external examination of the eye with assessment of the state of periorbital tissues, determination of the shape and size of the palpebral fissure (vertical size), position of the eye in orbit, Hertel exophthalmometry, ultrasound scanning and computed tomography of the orbits. Genetic analysis of the polymorphism of the studied genes was carried out using real-time polymerase chain reaction (real-time PCR).

RESULTS

The study did not find patterns in the distribution of homo- and heterozygous genotypes of A6986G polymorphic markers of the CYP3A5 gene, 6 C>T intron of the CYP3A4 gene and rs6190 of the NR3C1 gene in patients with endocrine ophthalmopathy and their effect on the glucocorticoid response (p>0.05).

CONCLUSION

Results of pharmacogenetic testing of the gene for the glucocorticoid receptor NR3C1 and cytochrome P450 do not provide a reliable confirmation of the influence of the polymorphism of the studied genes on the effectiveness of glucocorticoid therapy in patients with endocrine ophthalmopathy.

Toxicological Screening of Four Bioactive Citroflavonoids: In Vitro, In Vivo, and In Silico Approaches

Many studies describe different pharmacological effects of flavonoids on experimental animals and humans. Nevertheless, few ones are confirming the safety of these compounds for therapeutic purposes. This study aimed to investigate the preclinical safety of naringenin, naringin, hesperidin, and quercetin by in vivo, in vitro, and in silico approaches. For this, an MTT-based cytotoxicity assay in VERO and MDCK cell lines was performed. In addition, acute toxicity was evaluated on Wistar rats by OECD Guidelines for the Testing of Chemicals (Test No. 423: Acute Oral Toxicity-Class Method). Furthermore, we used the ACD/Tox Suite to predict toxicological parameters such as hERG channel blockade, CYP450 inhibition, and acute toxicity in animals. The results showed that quercetin was slightly more cytotoxic on cell lines (IC₅₀ of 219.44 ± 7.22 mM and 465.41 ± 7.44 mM, respectively) than the other citroflavonoids. All flavonoids exhibited an LD₅₀ value > 2000 mg/kg, which classifies them as low-risk substances as OECD guidelines established. Similarly, predicted LD⁵⁰ was LD₅₀ > 300 to 2000 mg/kg for all flavonoids as acute toxicity assay estimated. Data suggests that all these flavonoids did not show significant toxicological effects, and they were classified as low-risk, useful substances for drug development.

Effects of Saikosaponin D on CYP1A2 and CYP2D6 in HepaRG Cells

Background

Bupleurum is one of the most important traditional Chinese medicines and an ingredient in many compound preparations. It is widely used together with other drugs in clinical practice, and thus there is great potential for drug–drug interactions. Saikosaponin D (SsD) is a major bioactive triterpenoid saponin extracted from Bupleurum with anti-inflammatory, anticancer, antioxidative, and antihepatic fibrosis effects. Effects of the main components of Bupleurum on cytochromes P450 (CYPs) need to be clarified in the clinical application of combination therapies of formulations containing SsD or Bupleurum.

Purpose

This study aimed to investigate the effects of SsD on the CYP1A2 and CYP2D6 mRNAs, protein expression, and relative enzyme activities in HepaRG cells.

Methods

HepaRG cells were cultured with SsD at concentrations of 0.5, 1, 5 and 10 μM for 72 hours. mRNA and protein expression of CYP1A2 and CYP2D6 were analyzed with real-time PCR and Western blot analysis. Relative enzyme activities were analyzed with HPLC based on consumption of the specific probe substrate.

Results

SsD significantly induced expression of mRNA and increased relative activity of CYP1A2 in HepaRG cells after the cells had been treated with SsD at concentrations of 1, 5 and 10 μM. SsD also induced protein expression of CYP1A2 at concentrations of 5 and 10 μM. SsD exhibited an inductive effect on CYP2D6 mRNA and protein expression, while increasing the relative activity of CYP2D6 at concentrations of 5 and 10 μM.

Conclusion

This study is the first to investigate the effect of SsD on CYP1A2 and CYP2D6 in HepaRG cells, and the results may provide some useful information on potential drug–drug interactions related to clinical preparations containing SsD or Bupleurum.

Effects of mongolian medicine Terminalia chebula Retz. on 6 CYP450 enzymes in rats

Terminalia chebula Retz. (TCR) is a medicinal material commonly used in Mongolian medicine. After consulting the literature at home and abroad, current research on TCR focuses on chemical composition, pharmacodynamics, and fingerprints. The pharmacokinetics of TCR has not been reported. Cytochrome P450 (CYP450) is the main drug-metabolizing enzyme, and its activity may be induced or inhibited by certain drugs, resulting in drug interactions in clinical applications. The objective of this study was to establish a high performance liquid chromatography (HPLC) method that can simultaneously detect multiple probe drugs to determine the effect of TCR on the activities of CYP450 enzymes CYP2C19, CYP2E1, CYP2D6, CYP2C9, CYP3A4, and CYP1A2. Wistar rats (male) were divided into 5 groups according to the randomization principle, namely the control group, the positive group, and the high, medium and low dose group. After 15 days of continuous administration, the mixed probe drug was injected into the vein, and then a small amount of blood was collected from the orbital vein at different time points. After the samples were processed, the blood concentration of each probe drug was measured by the established HPLC method. The pharmacokinetic parameters of each probe drug were calculated using DAS software. Compared with the control group, the plasma clearance (CL) of chlorzoxazone and omeprazole decreased, and the maximum plasma concentration (C_max) and area under the curve (AUC) increased in the TCR group. The pharmacokinetic parameters of theophylline, midazolam, metoprolol, and tolbutamide did not differ significantly. The results indicated that TCR mainly inhibited the activities of CYP2E1 and CYP2C19, but had no effect on the activities of CYP1A2, CYP2C9, CYP3A4 and CYP2D6. Extra care should be taken when drugs metabolized by CYP2C19 and CYP2E1 enzymes are used in combination with TCR, as drug-herb interactions may occur. These results can guide the clinical application of related drugs and provide valuable information for drug interactions. The main component that affects enzyme activity may be tannins in the water extract.

Vitamin D, sport and health: a still unresolved clinical issue

Vitamin D metabolites have a pleiotropic role in human physiology, both in static and dynamic conditions, and a lot of vitamin D-related biological effects could influence physical and sport performances in athletes. Probably due to different factors (e.g., drugs, doping, nutrition, ultraviolet B radiation exposure), in athletes a very high prevalence of vitamin D inadequacy (i.e., deficiency or insufficiency) has been observed. Vitamin D inadequacy in athletes could be associated with specific health risks and to alterations of functional capacities, potentially influencing the fine adjustment of physical performances during training and sport competitions. When risk factors for vitamin D inadequacy exist, a preventive vitamin D supplementation is indicated, and if a vitamin D inadequacy is diagnosed, its supplementation is recommended. Unfortunately, on these issues many concerns remain unresolved. Indeed, it is not clear if athletes should be classified as a special population at increased risk for vitamin D inadequacy; moreover, in comparison to the non-athletic population, it is still not clear if athletes should have different reference ranges and different optimal target levels for serum vitamin D, if they have additional health risks, and if they need different type of supplementations (doses) for prevention and/or replacement therapy. Moreover, in athletes also the abuse of vitamin D supplements for ergogenic purposes raise different ethical and safety concerns. In this review, the main physio-pathological, functional and clinical issues that relate vitamin D to the world of athletes are described.

Anemarsaponin BII inhibits the activity of CYP3A4, 2D6, and 2E1 with human liver microsomes

CONTEXT

Anemarsaponin BII is one of the most active saponins isolated from Anemarrhena asphodeloides Bunge (Asparagaceae), a commonly used Chinese traditional paediatric medicine.

OBJECTIVE

This study investigates the effects of anemarsaponin BII on the activity of CYP450s to provide more guidance for the clinical use of anemarsaponin BII.

MATERIALS AND METHODS

Using various diagnostic substrates, the effects of a fixed concentration of anemarsaponin BII (100 μM) on the activity of eight main isoforms of CYP450s (CYP1A2, 2A6, 3A4, 2C8, 2C9, 2C19, 2D6 and 2E1) was first studied with pooled human liver microsomes (HLMs). Then, dose-dependent (0, 2.5, 5, 10, 25, 50 and 100 μM anemarsaponin BII) and time-dependent (0, 5, 10, 15 and 30 min) experiments were performed to obtain corresponding kinetic parameters.

RESULTS

Anemarsaponin BII showed significant inhibitory effects on the activity of CYP3A4, 2D6 and 2E1 with the IC₅₀ values of 13.67, 16.26 and 19.72 μM. Anemarsaponin BII acted as a non-competitive inhibitor of CYP3A4 with the K_I value of 6.72 μM and competitive inhibitors of CYP2D6 and 2E1 with the K_I values of 8.26 and 9.82 μM, respectively. Additionally, the inhibition of CYP3A4 was revealed to be time-dependent with the K_I value of 4.88 μM and the K_inact value of 0.053/min.

CONCLUSIONS

The inhibitory effect of anemarsaponin BII on the activity of CYP3A4, 2D6 and 2E1 indicated the potential drug-drug interaction between anemarsaponin BII and drugs metabolized by these CYP450s. Further in vivo experiments are needed to validate the potential drug-drug interactions.

[The pharmacogenetics of hypoglycemia and the glycemic variability at the patients ith type 2 diabetes mellitus]

AIM

To investigate the link between the hypoglycemia (registrated accurately by the professional Continuous Glucose Monitoring CGM; severe hypoglycemia at home) and the hetero-/homozygote carriage of single nucleotide polymorphisms (SNP) of cytochrome systems geneCYP2C9(rs1799853CYP2C9*2 иrs1057910CYP2C9*3) at the patients with Type 2 Diabetes Mellitus (T2DM) used sulphonylurea (SU).

MATERIALS AND METHODS

In Study Case-Control 120 T2DM-SU-patients genotyped by SNPs of geneCYP2C9(using PCR-RT) had been done the professional CGM (System iPro2, Medtronic) recorded Time in Range of Hypoglycemia (TIR-HYPO), level of Minimal CGM-hypoglycemia (MinGl) and standard CGM-parameters of Glycemic Variability. Severe hypoglycemia at home was recorded from visit to visit. The odds ratio (OR) of metabolic disturbances had been assessed for carriage SNPs in comparison with wide alleles.

RESULTS

The Study established that carriage of SNPsrs1799853andrs1057910geneCYP2C9at T2DM-SU-patients associated with rising of Glycemic Variability and frequency of CGM-hypoglycemia (MinGl decreasing, increasing of TIR-HYPO and number of Glycemia Excursion 4 mmol/L/h), as well as increasing severe hypoglycemia at home (p0.05). Thus, OR at the carriage ofrs1799853andrs1057910respectively equaled: for CGM-hypoglycemia 7.78 (3.0220.01) and 5.80 (0.23145.87); number of Glycemia Excursion 4 mmol/L/h 5.76 (2.2914.43) and 4.44 (1.4313.76); MinGl3.9 mmol/L 4.39 (1.7910.75) and 6.26 (1.8421.30); CV40% (vs30%) 3.63 (1.0412.62) and 15.22 (0.59393.94);p0.05.

CONCLUSION

At the real clinical practice the assessment of carriage of SNPs of geneCYP2C9before inclusion of SU to glucose-lowering scheme of T2DM-therapy it necessary to carry out for the detecting patients with a higher risk of hypoglycemia and rising of Glycemic Variability.

Risk assessment of the chiral pesticide fenamiphos in a human model: Cytochrome P450 phenotyping and inhibition studies

Fenamiphos (FS) is a chiral organophosphate pesticide that is used to control nematodes in several crops. Enantioselective differences may be observed in FS activity, bioaccumulation, metabolism, and toxicity. Humans may be exposed to FS through occupational and chronic (food, water, and environmental) exposure. FS may cause undesirable CYP450 pesticide-drug interactions, which may impact human health. Here, the CYP450 isoforms involved in enantioselective FS metabolism were identified, and CYP450 inhibition by rac-FS, (+)-FS, and (-)-FS was evaluated to obtain reliable information on enantioselective FS risk assessment in humans. CYP3A4 and CYP2E1 metabolized FS enantiomers, and CYP2B6 may participate in rac-FS metabolism. In addition, rac-FS, (+)-FS, and (-)-FS were reversible competitive CYP1A2, CYP2C19, and CYP3A4/5 inhibitors. High stereoselective inhibition potential was verified; rac-FS and (-)-FS strongly inhibited and (+)-FS moderately inhibited CYP1A2. Stereoselective differences were also detected for CYP2C19 and CYP3A4/5, which were strongly inhibited by rac-FS, (+)-FS, and (-)-FS. Our results indicated a high potential for CYP450 drug-pesticide interactions, which may affect human health. The lack of stereoselective research on the effect of chiral pesticides on the activity of CYP450 isoforms highlights the importance of assessing the risks of such pesticides in humans.

Evaluation of Potential Drug-Drug Interaction Risk of Pexidartinib With Substrates of Cytochrome P450 and P-Glycoprotein

Pexidartinib is approved for treatment of adults with symptomatic tenosynovial giant cell tumor. In vitro data showed pexidartinib's potential to inhibit and induce cytochrome P450 (CYP) 3A, inhibit CYP2C9, CYP2C19 and P‐glycoprotein (P‐gp). Herein, 2 open‐label, single‐sequence, crossover studies evaluated the drug‐drug interaction potential of pexidartinib on CYP enzymes (CYP2C9, CYP2C19, and CYP3A) and P‐gp. Thirty‐two subjects received single oral doses of midazolam (CYP3A substrate) and tolbutamide (CYP2C9 substrate) alone and after single and multiple oral doses of pexidartinib. Twenty subjects received single oral doses of omeprazole (CYP2C19 substrate) and digoxin (P‐gp substrate) alone or with pexidartinib. Analysis of variance was conducted to determine the effect of pexidartinib on various substrates’ pharmacokinetics. No drug‐drug interaction was concluded if the 90% confidence interval of the ratio of test to reference was within the range 80% to 125%. Coadministration of single and multiple doses of pexidartinib resulted in 21% and 52% decreases, respectively, in the area under the plasma concentration–time curve from time zero to the last measurable time point (AUC_last) of midazolam, whereas AUC_last values of tolbutamide increased 15% and 36%, respectively. Omeprazole exposure decreased on concurrent administration with pexidartinib, the metabolite‐to‐parent ratio was similar following omeprazole administration alone vs coadministration with pexidartinib; pexidartinib did not affect CYP2C19‐mediated metabolism. Maximum plasma concentrations of digoxin slightly increased (32%) with pexidartinib coadministration; no significant effect on digoxin AUC_last. These results indicate that pexidartinib is a moderate inducer of CYP3A and a weak inhibitor of CYP2C9 and does not significantly affect CYP2C19‐mediated metabolism or P‐gp transport.