Polymorphism of human cytochrome P450 enzymes and its clinical impact

Bioprinted high cell density liver model with improved hepatic metabolic functions

In vitro liver tissue models are valuable for studying liver function, understanding liver diseases, and screening candidate drugs for toxicity and efficacy. While three-dimensional (3D) bioprinting shows promise in creating various types of functional tissues, current efforts to engineer a functional liver tissue face challenges in replicating native high cell density (HCD) and maintaining long-term cell viability. HCD is crucial for establishing the cell-cell interactions necessary to mimic the liver's metabolic and detoxification functions. However, HCD bioinks exacerbate light scattering in light-based 3D bioprinting. In this study, we incorporated iodixanol into our bioink formulation to minimize light scattering, enabling the fabrication of hepatic tissue constructs with an HCD of 8 × 107 cells/mL while maintaining high cell viability (∼80 %). The printed dense hepatic tissue constructs showed enhanced cell-cell interactions, as evidenced by increased expression of E-cadherin and ZO-1. Furthermore, these constructs promoted albumin secretion, urea production, and P450 metabolic activity. Additionally, HCD hepatic tissue inactivated the YAP/TAZ pathway via cell-cell interactions, preserving primary hepatocyte functions. Further screening revealed that hepatocytes in the dense model were more sensitive to drug treatments than those in a lower-density hepatic model, highlighting the importance of HCD in recapitulating the physiological drug responses. Overall, our approach represents a significant advancement in liver tissue engineering, providing a promising platform for the development of physiologically relevant in vitro liver models for drug screening and toxicity testing.

In Vivo and In Vitro Pharmacokinetic Studies of a Dual Topoisomerase I/II Inhibitor

Due to high mortality rates, new and more effective drugs are urgently needed in cancer therapy. The novel dual topoisomerase inhibitor P8-D6, a dimethylaminoethyl-substituted pyridophenanthroline, showed in vitro impressive induction of apoptosis in tumors such as ovarian cancer or multiple myeloma compared to the current standard therapy. The purpose of this study was to investigate its in vitro and in vivo pharmacokinetics and to discover further potential drug candidates. Samples of plasma, various tissues, urine, feces, and cell culture supernatants were examined by HPLC. In addition, the efficacy of the metabolites against ovarian cancer was determined in vitro. Three phase I metabolites were identified in vitro and in vivo, and one phase II metabolite was identified in vivo. Among the metabolites, N-dealkylated P8-D6 (P8-D6 mono) achieved efficacy similar to that of P8-D6 in ovarian cancer. P8-D6 showed a relevant inhibitory effect on the efflux pumps P-GP (IC50 = 20.63 μM) and BCRP (16.32 μM). The calculated oral bioavailability in Sprague-Dawley rats was 21.5%, while P8-D6 had a high plasma protein binding of 99% and an extensive tissue distribution with an apparent volume of distribution between 57.69 (i.v.) and 82.92 (p.o.) L/m2. Both P8-D6 and its metabolites were detected in urine and feces. This study provides a basis for the clinical application of P8-D6 and has also identified P8-D6 mono as a very potent and metabolically stable drug candidate.

Antiepileptic drugs carbamazepine and valproic acid mediate transcriptional activation of CYP1A1 via aryl hydrocarbon receptor and regulation of estrogen metabolism

Cytochrome P450 1A1 (CYP1A1) actively catalyzes estrogen hydroxylation reactions and maintains the levels of neuroactive steroid estradiol. The widely prescribed first-line anti-epileptic drugs (AEDs) are considered to be a potent inducer of CYP1A1 and have also been observed to affect serum estradiol and calcium levels in patients with epilepsy. However, the ability of AEDs to interfere with CYP enzyme function and estrogen disposition is a relatively unexplored area. Here we investigate the effect of widely prescribed AEDs (carbamazepine and valproic acid) on CYP1A1 regulation and the levels of estradiol and calcium in cell supernatants of hepatocellular, HepG2, and neuronal, SH-SY5Y cells. We observed that both the AEDs significantly increased CYP1A1 expression and enzyme activity, which was accompanied by a decrease in estradiol and calcium levels in HepG2 cells. This induction of CYP1A1 mRNA and protein was fully prevented by aryl hydrocarbon receptor (AHR) knockdown and StemRegenin 1 (SR1) antagonism. Notably, the AEDs did not affect the AHR expression but regulated its nuclear translocation, potentially driving the transcriptional upregulation of CYP1A1. Furthermore, the knockdown of CYP1A1 in HepG2 cells elucidated a marked increase in estradiol and calcium levels. Later, this increase subsided upon AED exposure. Lastly, we observed a similar trend in estradiol and calcium alterations in SH-SY5Y cells on AED exposure, speculating the involvement of CYP1A1 induction via AEDs at neuronal sites. This work demonstrates that AEDs mediate the upregulation of CYP1A1 via an AHR-dependent mechanism and influence estrogen and calcium homeostasis.

Novel O-methylpyrimidine prodrugs of phenolic compounds bioactivated by aldehyde oxidase: Enhancing metabolic stability against first-pass conjugative metabolism in the intestine

Phenol-containing drugs may exhibit limited oral bioavailability due to first-pass conjugation in the intestine and liver, and potentially unfavorable biopharmaceutical properties imparted by the hydrogen-bond donor. We present a novel prodrug strategy in which O-methylpyrimidine modification masks the phenolic moiety and employs aldehyde oxidase (AO) to release the parent drug. Prototypical prodrugs of 4-hydroxy-tamoxifen (4OH-TAM), raloxifene (RAL), rotigotine, 5-hydroxy-tolterodine, and phentolamine were all substrates for AO-mediated parent drug release in liver cytosol from humans and every preclinical species evaluated. Reaction phenotyping confirmed the role of AO; hydralazine inhibited production of 4OH-TAM and RAL from their respective prodrugs in the human liver cytosol, and recombinant human AO activated those same prodrugs. Based on the identified byproduct, 5-(hydroxymethyl)uracil, and characterized 4OH-TAM prodrug metabolite intermediates, a mechanism is proposed, involving oxidation of the pyrimidine 4-position, followed by rate-limiting oxidation at the 2-position and subsequent C-O bond cleavage via an imine-methide intermediate. To determine a preclinical animal for proof-of-concept prodrug activation in vivo, we measured both absolute AO protein concentration and parent release for 2 prodrugs in the liver cytosol of multiple species and found that hamster was a promising candidate to model humans. After confirming a similar balance of AO-mediated prodrug conversion versus nonproductive/subsequent biotransformation in human and hamster hepatocytes, the 4OH-TAM prodrug and RAL prodrug 1 were progressed to a pharmacokinetic study in hamsters. A 30 mg/kg oral dose of RAL prodrug 1 demonstrated a 2-fold increase in RAL exposure compared with dosing parent RAL, indicating that this novel prodrug strategy has the potential to improve bioavailability in humans. SIGNIFICANCE STATEMENT: An aldehyde oxidase-mediated biotransformation that cleaves O-linked methylpyrimidine-masked phenolic moieties was identified, and this system employed for a novel prodrug bioactivation strategy. The research herein expands existing knowledge surrounding the metabolism capabilities of this enzyme and provides medicinal chemists with a tool to enhance the oral bioavailability of phenolic compounds that otherwise would be limited due to extensive phase II metabolism and possibly low permeability.

Enhancing clinical research with pharmacogenomics: a practical perspective

Pharmacogenomics (PGx) is transforming therapeutic development by providing insights into how genetic variations influence drug response, safety, and efficacy. This review provides a structured analysis of PGx in clinical research, beginning with an overview of key genes involved in drug metabolism, transport, and targets. Following this, it examines strategies for identifying PGx-relevant genes, including phenotype-driven, hypothesis-driven, population-focused, and clinical-driven approaches. Technical platforms such as PCR, MassARRAY, and next-generation sequencing are analyzed for their suitability in PGx studies. The discussion then shifts to assay validation processes, covering both analytical and clinical validation, to ensure data reliability in clinical trials. Finally, regulatory expectations for PGx in clinical trials are discussed, focusing on key requirements across all phases of drug development. This review aims to provide a clear and practical framework for integrating PGx into clinical research to enhance drug safety, efficacy, and personalized medicine.

Physiologically based pharmacokinetic (PBPK) modeling of gliclazide for different genotypes of CYP2C9 and CYP2C19

Gliclazide is a sulfonylurea hypoglycemic agent used to treat type 2 diabetes. Cytochrome P450 (CYP) 2C9 and CYP2C19 are primarily involved in the hepatic metabolism of gliclazide. The two CYP isozymes are highly polymorphic, and their genetic polymorphisms are known to significantly impact the pharmacokinetics of gliclazide. In the present study, the physiologically based pharmacokinetic (PBPK) model was developed using data from subjects whose pharmacokinetic parameters were influenced by the genetic polymorphisms of the CYP metabolic enzymes. All predicted plasma concentration-time profiles generated by the model showed visual agreement with the observed data, and the pharmacokinetic results were within the twofold error range. Individual simulation results showed additional metrics: average fold error (- 0.19 to 0.07), geometric mean fold error (1.13-1.56), and mean relative deviation (1.18-1.58) for AUC, Cmax, T1/2, Tmax, CL/F, and Vd values. These results met the standard evaluation criteria. The validation across a total of 8 studies and 7 races also satisfied the twofold error range for AUC, Cmax, and T1/2. Therefore, variations in gliclazide exposure according to individuals' CYP2C9 and CYP2C19 genotypes were properly captured through PBPK modeling in this study. This PBPK model may allow us to predict the gliclazide pharmacokinetics of patients with genetic polymorphisms in CYP2C9 and CYPC19 under various conditions, ultimately contributing to the realization of individualized drug therapy.

Role of HNF4A-AS1/HNRNPC-mediated HNF4A ubiquitination protection against ritonavir-induced hepatotoxicity

Ritonavir (RTV) is an important drug for anti-human immunodeficiency virus treatment and is mainly metabolized by cytochrome P450 (CYP) 3A4. Clinically, the most common side effect of RTV treatment is hepatoxicity. We previously showed that the long noncoding RNA hepatocyte nuclear factor 4 alpha (HNF4A) antisense 1 (HNF4A-AS1) negatively regulated CYP3A4 expression and participated in RTV-induced hepatotoxicity in vitro, but the mechanism has not been well understood. In this study, similar results were observed in the mouse, where liver-specific knockdown of Hnf4aos (homolog of human HNF4A-AS1) led to increased serum aspartate (∼1.8-fold) and alanine transaminase (∼2.4-fold) levels and enlarged and degenerated hepatocytes 24 hours after RTV administration. Meanwhile, endoplasmic reticulum stress markers GRP78, PDI, and XBP-1 increased about 2.4-fold, 2.1-fold, and 2.7-fold, respectively. The aggravated liver injury correlated with Hnf4aos knockdown, attributable to heightened Cyp3a11 (homolog of human CYP3A4) expression (mRNA and protein levels were 1.8-fold and 2.5-fold, respectively). Importantly, in vitro studies revealed the underlying mechanism that HNF4A-AS1 mediated the interaction between heterogeneous nuclear ribonucleoprotein C and HNF4A, whereas heterogeneous nuclear ribonucleoprotein C promoted HNF4A degradation through the ubiquitination pathway, thereby decreasing CYP3A4 expression and alleviating RTV-induced liver injury. Overall, our findings unveil a novel mechanism by which HNF4A-AS1 regulates CYP3A4 expression to influence RTV-induced liver injury. SIGNIFICANCE STATEMENT: HNF4A-AS1 negatively regulates the expression of CYP3A4, whose overexpression is highly correlated with ritonavir (RTV)-induced liver injury. In this study, the role of Hnf4aos (homolog of human HNF4A-AS1) in RTV-induced hepatotoxicity was confirmed in mice. We found that HNF4A-AS1 and HNRNPC form a complex and facilitate the ubiquitination and degradation of HNF4A protein, thereby decreasing CYP3A4 expression and alleviating RTV hepatotoxicity.

Maternal MitoQ Treatment Is Protective Against Programmed Alterations in CYP Activity Due to Antenatal Dexamethasone

Background/Objectives: In pregnancy threatened by preterm birth, antenatal corticosteroids (ACS) are administered to accelerate fetal lung maturation. However, they have side effects, including the production of reactive oxygen species that can impact cytochrome P450 (CYP) activity. We hypothesised that antioxidants could protect a fetus treated with ACS during gestation and prevent the programming of altered hepatic CYP activity in the offspring. The primary outcome of our study was the impact of different maternal treatments on the activity of hepatic drug-metabolising enzymes in offspring. Methods: At 100 ± 1 days gestational age (dGA, term = 147 dGA), 73 ewes were randomly allocated to the following: saline (5 mL IV daily 105-137 ± 2 dGA, n = 17), ACS (Dexamethasone (Dex); 12 mg IM at 115 and 116 dGA; n = 25), MitoQ (6 mg/kg MS010 IV, daily bolus 105-137 ± 2 dGA; n = 17) or Dex and MitoQ (Dex+MitoQ; n = 14). CYP activity and protein abundance were assessed using functional assays and Western blot. Results: Dex decreased the hepatic activity of fetal CYP3A (-56%, PDex = 0.0322), and 9 mo lamb CYP1A2 (-22%, PDex = 0.0003), CYP2B6 (-36%, PDex = 0.0234), CYP2C8 (-34%, PDex = 0.0493) and CYP2E1 (-57%, PDex = 0.0009). For all, except CYP1A2, activity returned to control levels with Dex+MitoQ in 9 mo lambs. In 9 mo lambs, MitoQ alone increased activity of CYP2B6 (+16%, PMitoQ = 0.0011) and CYP3A (midazolam, +25%, PMitoQ = 0.0162) and increased CAT expression (PMitoQ = 0.0171). Dex+MitoQ increased CYP3A4/5 activity (testosterone, +65%, PIntx < 0.0003), decreased CYP1A2 activity (-14%, PIntx = 0.0036) and decreased mitochondrial abundance (PIntx = 0.0051). All treatments decreased fetal hepatic DRP1, a regulator of mitochondrial fission (PDex = 0.0055, PMitoQ = 0.0006 and PIntx = 0.0034). Conclusions: Antenatal Dex reduced activity of only one CYP in the fetus but programmed the reduced activity of several hepatic CYPs in young adult offspring, and this effect was ameliorated by combination with MitoQ.

A machine learning approach to predict treatment efficacy and adverse effects in major depression using CYP2C19 and clinical-environmental predictors

BACKGROUND

Major depressive disorder (MDD) is among the leading causes of disability worldwide and treatment efficacy is variable across patients. Polymorphisms in cytochrome P450 2C19 (CYP2C19) play a role in response and side effects to medications; however, they interact with other factors. We aimed to predict treatment outcome in MDD using a machine learning model combining CYP2C19 activity and nongenetic predictors.

METHODS

A total of 1410 patients with MDD were recruited in a cross-sectional study. We extracted the subgroup treated with psychotropic drugs metabolized by CYP2C19. CYP2C19 metabolic activity was determined by the combination of *1, *2, *3, and *17 alleles. We tested if treatment response, treatment-resistant depression, and side effects could be inferred from CYP2C19 activity in combination with clinical-demographic and environmental features. The model used for the analysis was based on a decision tree algorithm using five-fold cross-validation.

RESULTS

A total of 820 patients were treated with CYP2C19 metabolized drugs. The predictive performance of the model showed at best.70 accuracy for the classification of treatment response (average accuracy = 0.65, error = ±0.047) and an average accuracy of approximately 0.57 across all the tested outcomes. Age, BMI, and baseline depression severity were the main features influencing prediction across all the tested outcomes. CYP2C19 metabolizing status influenced both response and side effects but to a lower extent than the previously indicated features.

CONCLUSION

Predictive modeling could contribute to precision psychiatry. However, our study underlines the difficulty in selecting variables with sufficient impact on complex outcomes.

Utilization of Cannabidiol in Post-Organ-Transplant Care

Cannabidiol (CBD) is one of the major phytochemical constituents of cannabis, Cannabis sativa, widely recognized for its therapeutic potential. While cannabis has been utilized for medicinal purposes since ancient times, its psychoactive and addictive properties led to its prohibition in 1937, with only the medical use being reauthorized in 1998. Unlike tetrahydrocannabinol (THC), CBD lacks psychoactive and addictive properties, yet the name that suggests its association with cannabis has significantly contributed to its public visibility. CBD exhibits diverse pharmacological properties, most notably anti-inflammatory effects. Additionally, it interacts with key drug-metabolizing enzyme families, including cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT), which mediate phase I and phase II metabolism, respectively. By binding to these enzymes, CBD can inhibit the metabolism of co-administered drugs, which can potentially enhance their toxicity or therapeutic effects. Mild to moderate adverse events associated with CBD use have been reported. Advances in chemical formulation techniques have recently enabled strategies to minimize these effects. This review provides an overview of CBD, covering its historical background, recent clinical trials, adverse event profiles, and interactions with molecular targets such as receptors, channels, and enzymes. We particularly emphasize the mechanisms underlying its anti-inflammatory effects and interaction with drugs relevant to organ transplantation. Finally, we explore recent progress in the chemical formulation of CBD in order to enhance its bioavailability, which will enable decreasing the dose to use and increase its safety and efficacy.

Genome-wide association study reveals shared and distinct genetic architecture of fatty acids and oxylipins in the Hispanic Community Health Study/Study of Latinos

Bioactive fatty acid-derived oxylipin molecules play key roles mediating inflammation and oxidative stress. Circulating levels of fatty acids and oxylipins are influenced by environmental and genetic factors; characterizing the genetic architecture of bioactive lipids could yield new insights into underlying biology. We performed a genome-wide association study (GWAS) of 81 fatty acids and oxylipins in 11,584 Hispanic Community Health Study/Study of Latinos (HCHS/SOL) participants with genetic and lipidomic data measured at study baseline (58.6% female, mean age = 46.1 years (standard deviation 13.8)). Additionally, given the effects of central obesity on inflammation, we examined interactions with waist circumference using two-degree-of-freedom joint tests. Thirty-three of the 81 oxylipins and fatty acids were significantly heritable (heritability range: 0-32.7%). Forty (49.4%) oxylipins and fatty acids had at least one genome-wide significant (p < 6.94E-11) variant resulting in 19 independent genetic loci. Six loci (lead variant minor allele frequency [MAF] range: 0.08-0.50), including desaturase-encoding FADS and OATP1B1 transporter protein-encoding SLCO1B1, exhibited associations with two or more fatty acids and oxylipins. At several of these loci, there was evidence of colocalization of the top variant across fatty acids and oxylipins. The remaining loci were only associated with one oxylipin or fatty acid and included several CYP loci. We also identified an additional rare variant (MAF = 0.002) near CARS2 in two-degree-of-freedom tests. Our analyses revealed shared and distinct genetic architecture underlying fatty acids and oxylipins, providing insights into genetic factors and motivating work to characterize these compounds and elucidate their roles in disease.

In vitro assays identified thiohydantoins with anti-trypanosomatid activity and molecular modelling studies indicated possible selective CYP51 inhibition

This work investigates the anti-trypanosomal activities of ten thiohydantoin derivatives against the parasite Trypanosoma cruzi. Compounds with aliphatic chains (THD1, THD3, and THD5) exhibited the most promising IC50 against the epimastigote form of T. cruzi. Also, it showed lower cytotoxicity to mammalian cells. THD3 and THD5 (IC50 = 72.4 µg/mL and 115 µg/mL) presented great activity against trypomastigote and amastigote forms (IC50 = 47.7 µg/mL and 34.1 µg/mL). THD5 had high selectivity index (SI = 15.1) against the amastigote form. The molecular docking and molecular dynamics simulations were performed to understand the interaction between the THD and the important target CYP51 enzyme essential to T. cruzi. THD3 and THD5 were found to have strong interactions within the hydrophobic channel of CYP51 due to their aliphatic side chains, leading to favorable binding free energies. Despite the possibility of cross-reactivity between THD5 and human CYP2C9, the results indicate low identity and similarity between the homolog enzymes and possible selectivity of THD5 for the protozoan one, suggesting that these compounds could inhibit sterol biosynthesis, crucial for the parasite's survival​. These findings indicate that THD3 and THD5 are promising hits for the development of Chagas disease treatments. To fully validate this potential, carrying out enzymatic and other in vitro and in vivo assays is essential in the future.

Optimising pirfenidone dosage regimens in idiopathic pulmonary fibrosis: towards a guide for personalised treatment

Idiopathic Pulmonary Fibrosis (IPF) is a chronic respiratory disorder for which pirfenidone is the recommended first-line anti-fibrotic treatment. While pirfenidone has demonstrated efficacy in slowing the progression of IPF, its use is associated with several challenges and unresolved issues that impact patient outcomes. Pirfenidone administration can result in gastrointestinal side effects, photosensitivity reactions, and significant drug interactions, particularly in patients with hepatic impairment. For those who experience intolerable side effects, dose reductions or temporary discontinuations are frequently employed. However, there is limited data on the efficacy of reduced doses, creating uncertainty about the balance between tolerability and therapeutic benefit.The aim of this study is to evaluate the currently proposed dosage adjustments and to develop new dosage regimens tailored to the needs of patients. Simulations were conducted to explore pirfenidone pharmacokinetics under various challenging conditions, including dose titration, withdrawal, retitration, moderate and severe hepatic impairment, co-administration of moderate (e.g. omeprazole) and strong (e.g. smoking) inducers of the CYP1A2 enzyme, gastrointestinal adverse events, and photosensitivity reactions.Simulations led to specific recommendations for physicians regarding dosage regimens in each condition. The recommended dosage adjustments are designed to maintain concentrations within acceptable levels, ensuring both safe and effective treatment.

[Application of Human Liver Organoids for Pharmaceutical Research]

Human liver organoids are expected to be a hepatocyte source for preclinical in vitro studies of drug metabolism and disposition. Although these organoids show long-term proliferation, their hepatic functions remain low. Therefore, it is necessary to enhance the hepatic functions of primary human hepatocyte (PHH)-derived organoids. Here, we propose a novel method for two dimensional (2D)-cultured hepatic differentiation from PHH-derived organoids. PHH-derived organoids were established from cryopreserved PHHs. When cultured under a 2D condition, the single cells from PHH-derived organoids were seeded on collagen type I-coated plates. Then, optimal conditions for hepatic differentiation were screened using several compounds, cytokines and growth factors. Based on the results of the screening, we determined the 2D-cultured hepatic differentiation method from PHH-derived organoids. Hepatic gene expressions in PHH-derived organoids-derived hepatocytes (Org-HEPs) were greatly increased, compared to those in PHH-derived organoids. An RNA-seq analysis showed that gene expressions related to pharmacokinetics were upregulated in Org-HEPs compared to PHH-derived organoids. The metabolic activities of CYP1A2, CYP2C8, CYP2E1 and CYP3A4 were at levels comparable to those in PHHs. We also treated Org-HEPs and PHHs with hepatotoxic drugs, such as acetaminophen, troglitazone, amiodarone and clozapine. The cell viability of Org-HEPs was almost the same as that of PHHs. These results suggested that PHH-derived organoids could be differentiated into highly functional hepatocytes in 2D culture, and Org-HEPs could be used for hepatotoxicity tests. Thus, Org-HEPs will be useful for pharmaceutical research.

The Influence of Genetic Polymorphisms in Cytochrome P450 (CYP1A1 and 2D6) Gene on the Susceptibility to Philadelphia Negative Chronic Myeloid Leukemia in Sudanese Patients

The most frequent type of leukemia in Africa is chronic myeloid leukemia (CML). The genetic background of the rarer Philadelphia chromosome (Ph) Ph-ve (BCR-ABL-ve) subform of CML is largely unknown in African patients. Therefore, in this study, we aimed to investigate the role of CYP1A1 and 2D6 SNPs in the pathogenesis of Ph-ve CML in the Sudanese population. A total of 126 patients were selected for analysis. DNA was isolated from Ph-ve CML patients and a control group for PCR-RFLP analysis of SNPs CYP1A1*2C and CYP2D6*4. The CYP1A1 gene significantly expressed the GG variant genotype (p < 0.05) in 23.1% of the Ph-ve CML patients and 8% of the control group. In contrast, the CYP2D6 GA genotype was strongly associated with a reduced risk of developing Ph-ve CML (p < 0.005) with a frequency of 50% in Ph-ve patients and 93% in the control group. CYP1A1 GG polymorphism was prevalent among patients with Ph-ve CML, suggesting its role in disease development. CYP2D6 GA (IM) polymorphism was uncommon among patients, compared with the control group, possibly indicating a protective role of the polymorphisms from Ph-ve CML. This study demonstrates an association between key metabolic SNPs and Ph-ve CML and highlights the role that altered xenobiotic metabolism may play in the development of several human leukemias.

CYP3A4 and CYP3A5: the crucial roles in clinical drug metabolism and the significant implications of genetic polymorphisms

CYP3A, a key member of the cytochrome P450 (CYP450) superfamily, is integral to drug metabolism, processing a substantial portion of medications. Their role in drug metabolism is particularly prominent, as CYP3A4 and CYP3A5 metabolize approximately 30-50% of known drugs. The genetic polymorphism of CYP3A4/5 is significant inter-individual variability in enzymatic activity, which can result in different pharmacokinetic profiles in response to the same drug among individuals. These polymorphisms can lead to either increased drug toxicity or reduced therapeutic effects, requiring dosage adjustments based on genetic profiles. Consequently, the study of the enzymatic activity of CYP3A4/5 gene variants is of great importance for the formulation of personalized treatment regimens. This article first reviews the role of CYP3A4/5 in drug metabolism in the human body, including inhibitors and inducers of CYP3A4/5 and drug-drug interactions. In terms of genetic polymorphism, it discusses the detection methods, enzymatic kinetic characteristics, and clinical guidelines for CYP3A5. Finally, the article summarizes the importance of CYP3A4/5 in clinical applications, including personalized therapy, management of drug-drug interactions, and adjustment of drug doses. This review contributes to the understanding of the functions and genetic characteristics of CYP3A4/5, allowing for more effective clinical outcomes through optimized drug therapy.

Bergenin inhibits hepatic fat deposition by activating the AMPK signaling pathway, thereby attenuating alcoholic liver disease

Alcoholic liver disease (ALD) is a prevalent liver condition that arises from prolonged and excessive alcohol intake. Bergenin (BER) is an effective phytotherapeutic agent that exhibits pharmacological properties, including anti-inflammatory and anti-oxidative effects. To establish an in vivo model of ALD, C57BL/6 mice were continuously fed a high-fat diet (HFD) and administered alcohol gavage for 8 weeks, while concurrently administering BER and evaluated for therapeutic effects. After modeling, the therapeutic effects of BER were evaluated by observing histopathological changes and the detection of relevant biochemical indicators in mice. In addition, RNA sequencing of liver tissues was performed to analyze differentially expressed genes and to investigate the associated signaling pathways in order to elucidate the protective mechanisms of BER. These differentially expressed genes were mainly enriched in lipid metabolism pathways and the cytochrome P450 metabolism of exogenous substances. Subsequently, HepG2 was co-treated with sodium oleate (NaOA) and ethanol to establish an in vitro model, and the specific mechanism by which BER ameliorates ALD was further analyzed in depth. AMPK inhibitor, Compound C (CC), was demonstrated to significantly inhibit the regulation of lipid metabolism by BER in vitro. Finally, the differentially expressed genes selected were validated through qRT-PCR and Western blot analysis. Collectively, our findings revealed that BER effectively alleviated liver injury caused by alcohol and HFD in mice, significantly suppressing lipid deposition in ALD, enhancing alcohol metabolism, and mitigating oxidative stress.

Non-additivity of the functional properties of individual P450 species and its manifestation in the effects of alcohol consumption on the metabolism of ketamine and amitriptyline

To explore functional interconnections between multiple P450 enzymes and their manifestation in alcohol-induced changes in drug metabolism, we implemented a high-throughput study of correlations between the composition of the P450 pool and the substrate saturation profiles (SSP) of amitriptyline and ketamine demethylation in a series of 23 individual human liver microsomes preparations from donors with a known history of alcohol consumption. The SSPs were approximated with linear combinations of three Michaelis-Menten equations with globally optimized KM (substrate affinity) values. This analysis revealed a strong correlation between the rate of ketamine metabolism and alcohol exposure. For both substrates, alcohol consumption caused a significant increase in the role of the low-affinity enzymes. The amplitudes of the kinetic components and the total rate were further analyzed for correlations with the abundance of 11 major P450 enzymes assessed by global proteomics. The maximal rate of metabolism of both substrates correlated with the abundance of CYP3A4, their predicted principal metabolizer. However, except for CYP2D6 and CYP2E1, responsible for the low-affinity metabolism of ketamine and amitriptyline, respectively, none of the other potent metabolizers of the drugs revealed a positive correlation. Instead, in the case of ketamine, we observed negative correlations with the abundances of CYP1A2, CYP2C9, and CYP3A5. For amitriptyline, the data suggest inhibitory effects of CYP1A2 and CYP2A6. Our results demonstrate the importance of functional interactions between multiple P450 species and their decisive role in the effects of alcohol exposure on drug metabolism.

Unidentified CYP2D6 genotype does not affect pharmacological treatment for patients with first episode psychosis

BACKGROUND

Research on the pharmacogenetic influence of hepatic CYP450 enzyme 2D6 (CYP2D6) on metabolism of drugs for psychosis and associated outcome has been inconclusive. Some results suggest increased risk of adverse reactions in poor and intermediate metabolizers, while others find no relationship. However, retrospective designs may fail to account for the long-term pharmacological treatment of patients. Previous studies found that clinicians adapted risperidone dose successfully without knowledge of patient CYP2D6 phenotype.

AIM

Here, we aimed to replicate the results of those studies in a Dutch cohort of patients with psychosis (N = 418) on pharmacological treatment.

METHOD

We compared chlorpromazine-equivalent dose between CYP2D6 metabolizer phenotypes and investigated which factors were associated with dosage. This was repeated in two smaller subsets; patients prescribed pharmacogenetics-actionable drugs according to published guidelines, and risperidone-only as done previously.

RESULTS

We found no relationship between chlorpromazine-equivalent dose and phenotype in any sample (complete sample: p = 0.3, actionable-subset: p = 0.82, risperidone-only: p = 0.34). Only clozapine dose was weakly associated with CYP2D6 phenotype (p = 0.03).

CONCLUSION

Clinicians were thus not intuitively adapting dose to CYP2D6 activity in this sample, nor was CYP2D6 activity associated with prescribed dose. Although the previous studies could not be replicated, this study may provide support for existing and future pharmacogenetic research.

A type of self-assembled and label-free DNA-modified electrochemical biosensors based on magnetic α-Fe2O3/Fe3O4 heterogeneous nanorods for ultra-sensitive detection of CYP2C19*3

CYP2C19*3 enzyme plays a pivotal role in drug metabolism and is tightly regulated by the CYP2C19*3 gene. Therefore, quantification of CYP2C19*3 gene holds paramount importance for achieving personalized medication guidance in precision medicine. In this project, the magnetic electrochemical biosensors were constructed for the ultra-sensitive detection of CYP2C19*3 gene. Employing magnetic α-Fe2O3/Fe3O4@Au as the matrixes for signal amplification, CYP2C19*3 complementary chains (c-ssDNA) were bound to their surfaces through gold-sulfur bonds with subsequent specific sites blockade by bovine serum albumin (BSA) to form the α-Fe2O3/Fe3O4@Au/c-ssDNA/BSA biosensors. This design enabled efficient biosensors separation, target gene capture, and self-assembly on the electrode surface, enhancing the response signal. The biosensors exhibited excellent capture capabilities with a wide linear range (1 pM-1 μM), a low detection limit of 0.2710 pM, a quantitation limit of 0.9033 pM, reproducibility with an RSD value of 1.26 %, and stable storage for at least one week. The RSD value of CYP2C19*3 in serum samples consistently remained below 4.5 %, with a recovery rate ranging 95.52 % from 102.71 %. Moreover, the target gene could be accurately identified and captured in a mixed system of multiple nucleotide mutants of the CYP2C19*3 gene, suggesting a promising applicability and popularization.

Computational journey to unveil organophosphorothioate pesticides' metabolism: A focus on chlorpyrifos and CYP2C19 mutational landscape

Organophosphorothioates (OPT) are pesticides impacting human, animal and environmental health. They enter the environment worldwide, primarily due to their application as insecticides. OPTs are mainly neurotoxic upon bioactivation and inhibition of brain and serum acetylcholinesterase (AChE). Although OPTs are meant to target insects, they are potentially toxic to many other species (including humans), posing risks to non-target organisms and ecosystems. Certain cytochromes P450 (CYP) promote OPTs bioactivation, forming the corresponding oxon metabolites, while others catalyse their detoxification. Understanding the molecular basis of such a bivalent fate may help to clarify the toxicity of OPTs in living organisms, with far-reaching consequences to understand their impact on living organisms and improve risk assessment, to cite but a few. However, although crucial, the underpinning mechanisms still lay unclear. Here, a validated computational pipeline revealed the molecular reasons underlying the differential metabolism of chlorpyrifos in humans by CYP2C19, a primal route of detoxification, and its bioactivation by CYP2B6. The analysis drew the diverse occupancy of the CYP pocket and orientation to the heme group as a convincing evidence-based explanation for the opposite transformation. Moreover, this study explored the impact of CYP2C19 mutational landscape giving a blueprint to unveil the molecular basis of OPTs metabolism and toxicological implications from an inter-individual perspective. Taken together, the outcome described for the first time to the best of our knowledge a structural rationale for the bioactivation/detoxification of OPTs improving the current understanding of their toxicity from a molecular standpoint.

Human Cytochrome P450 Cancer-Related Metabolic Activities and Gene Polymorphisms: A Review

BACKGROUND

Cytochromes P450 (CYPs) are heme-containing oxidoreductase enzymes with mono-oxygenase activity. Human CYPs catalyze the oxidation of a great variety of chemicals, including xenobiotics, steroid hormones, vitamins, bile acids, procarcinogens, and drugs.

FINDINGS

In our review article, we discuss recent data evidencing that the same CYP isoform can be involved in both bioactivation and detoxification reactions and convert the same substrate to different products. Conversely, different CYP isoforms can convert the same substrate, xenobiotic or procarcinogen, into either a more or less toxic product. These phenomena depend on the type of catalyzed reaction, substrate, tissue type, and biological species. Since the CYPs involved in bioactivation (CYP3A4, CYP1A1, CYP2D6, and CYP2C8) are primarily expressed in the liver, their metabolites can induce hepatotoxicity and hepatocarcinogenesis. Additionally, we discuss the role of drugs as CYP substrates, inducers, and inhibitors as well as the implication of nuclear receptors, efflux transporters, and drug-drug interactions in anticancer drug resistance. We highlight the molecular mechanisms underlying the development of hormone-sensitive cancers, including breast, ovarian, endometrial, and prostate cancers. Key players in these mechanisms are the 2,3- and 3,4-catechols of estrogens, which are formed by CYP1A1, CYP1A2, and CYP1B1. The catechols can also produce quinones, leading to the formation of toxic protein and DNA adducts that contribute to cancer progression. However, 2-hydroxy- and 4-hydroxy-estrogens and their O-methylated derivatives along with conjugated metabolites play cancer-protective roles. CYP17A1 and CYP11A1, which are involved in the biosynthesis of testosterone precursors, contribute to prostate cancer, whereas conversion of testosterone to 5α-dihydrotestosterone as well as sustained activation and mutation of the androgen receptor are implicated in metastatic castration-resistant prostate cancer (CRPC). CYP enzymatic activities are influenced by CYP gene polymorphisms, although a significant portion of them have no effects. However, CYP polymorphisms can determine poor, intermediate, rapid, and ultrarapid metabolizer genotypes, which can affect cancer and drug susceptibility. Despite limited statistically significant data, associations between CYP polymorphisms and cancer risk, tumor size, and metastatic status among various populations have been demonstrated.

CONCLUSIONS

The metabolic diversity and dual character of biological effects of CYPs underlie their implications in, preliminarily, hormone-sensitive cancers. Variations in CYP activities and CYP gene polymorphisms are implicated in the interindividual variability in cancer and drug susceptibility. The development of CYP inhibitors provides options for personalized anticancer therapy.

Genetic ancestry in population pharmacogenomics unravels distinct geographical patterns related to drug toxicity

Genetic ancestry plays a major role in pharmacogenomics, and a deeper understanding of the genetic diversity among individuals holds immerse promise for reshaping personalized medicine. In this pivotal study, we have conducted a large-scale genomic analysis of 1,136 pharmacogenomic variants employing machine learning algorithms on 3,714 individuals from publicly available datasets to assess the risk proximity of experiencing drug-related adverse events. Our findings indicate that Admixed Americans and Europeans have demonstrated a higher risk of experiencing drug toxicity, whereas individuals with East Asian ancestry and, to a lesser extent, Oceanians displayed a lower risk proximity. Polygenic risk scores for drug-gene interactions did not necessarily follow similar assumptions, reflecting distinct genetic patterns and population-specific differences that vary depending on the drug class. Overall, our results provide evidence that genetic ancestry is a pivotal factor in population pharmacogenomics and should be further exploited to strengthen even more personalized drug therapy.

Induction of cytochrome P450 via upregulation of CAR and PXR: a potential mechanism for altered florfenicol metabolism by macranthoidin B in vivo

Introduction

Macranthoidin B (MB) is a primary active component of Flos Lonicerae. In Chinese veterinary clinics, Flos Lonicerae is frequently used in combination with florfenicol to prevent and treat infections in livestock and poultry. However, potential interactions between Flos Lonicerae and florfenicol remain unclear. To systematically study these interactions, it is crucial to investigate the individual phytochemicals within Flos Lonicerae. Therefore, MB was selected for this study to assess its effect on the pharmacokinetics of florfenicol in vivo and to explore the underlying mechanisms involved.

Methods

Male Sprague-Dawley rats were administered MB (60 mg/kg BW) or sterile water orally for 7 consecutive days. On the 8th day, a single oral dose of florfenicol (25 mg/kg BW) was given. Florfenicol pharmacokinetics were analyzed using ultra-high performance liquid chromatography. The hepatic expression levels of cytochrome P450 (CYP1A2, CYP2C11, CYP3A1), UDP-glucuronosyltransferase (UGT1A1), P-glycoprotein (P-gp), and nuclear receptors, including constitutive androstane receptor (CAR), pregnane X receptor (PXR), and retinoid X receptor alpha (RXRα), were quantified via reverse transcription-quantitative polymerase chain reaction and Western blotting (WB). Hepatic CYP1A2 and CYP2C11 activities were measured using a cocktail method. Additionally, the subcellular expression and localization of CAR, PXR, and RXRαin hepatocytes was assessed using WB and immunofluorescence staining.

Results

MB significantly reduces the AUC(0-∞) and MRT(0-∞) of florfenicol. MB also markedly upregulates the mRNA and protein expression of hepatic CYP1A2 and CYP2C11, along with their catalytic activities. Substantial upregulation of CAR and PXR proteins occurs in the hepatocyte nucleus, along with significant nuclear colocalization of the transcriptionally active CAR/RXRα and PXR/RXRαheterodimers, indicating MB-induced nuclear translocation of both CAR and PXR.

Discussion

These findings suggest that MB-induced alterations in florfenicol pharmacokinetics, particularly its accelerated elimination, may be due to increased expression and activities of CYP1A2 and CYP2C11, with CAR and PXR potentially involved in these regulatory effects. Further investigation is yet needed to fully elucidate the clinical implications of these interactions concerning the efficacy of florfenicol in veterinary medicine.

Preclinical metabolism and metabolic drug-drug interaction profile of pedunculoside and rotundic acid

Pedunculoside and rotundic acid, the most abundant components in plants of the genus Ilex L. (Aquifoliaceae), exhibit biological and pharmacological significance in the treatment of cardiovascular diseases. However, there have been few studies on their metabolism. This study performed a systematic metabolism study of pedunculoside and rotundic acid and evaluated their potential for herb-drug interaction. Pedunculoside or rotundic acid was incubated with human liver microsomes and recombinant human metabolic enzymes, and analyzed using LC-Q-TOF/MS and LC-MS/MS. Pedunculoside was found to be the most stable in human liver microsomes, whereas rotundic acid was easily metabolized. Eight pedunculoside metabolites and six rotundic acid metabolites were detected and tentatively identified through hydroxylation, glucuronidation, acetylation, and glucose conjugation. Hydroxylation of pedunculoside is mainly catalyzed by CYP3A4/5 and partly by CYP2C8. Hydroxylation of rotundic acid is almost exclusively catalyzed by CYP3A4/5, and its glucuronidation reaction is mediated by UGT1A4. Neither pedunculoside nor rotundic acid showed CYP inhibition (IC50 values > 50 μM) with the probe substrates of major CYP isoforms during incubation with human liver microsomes. This study is the first investigation into the in vitro metabolism of pedunculoside and rotundic acid using human liver microsomes. It also aims to assess their potential as perpetrators of drug-drug interactions involving CYP enzymes. The comprehensive metabolism and drug interaction studies of pedunculoside and rotundic acid enable us to evaluate and manage potential risks with their use in pharmacotherapy.

Development of a hepatic differentiation method in 2D culture from primary human hepatocyte-derived organoids for pharmaceutical research

Human liver organoids derived from primary human hepatocytes (PHHs) are expected to be a hepatocyte source for preclinical in vitro studies of drug metabolism and disposition. Because hepatic functions of these organoids remain low, it is necessary to enhance the hepatic functions. Here, we develop a novel method for two dimensional (2D)-cultured hepatic differentiation from PHH-derived organoids by screening several compounds, cytokines, and growth factors. Hepatic gene expressions in the hepatocyte-like cells differentiated from PHH-derived organoids (Org-HEPs) were greatly increased, compared to those in PHH-derived organoids. The metabolic activities of cytochrome P450 (CYP) 1A2, CYP2C8, CYP2C19, CYP2E1, and CYP3A4 were at levels comparable to those in PHHs. The cell viability of Org-HEPs treated with hepatotoxic drugs was almost the same as that of PHHs. Thus, PHH-derived organoids could be differentiated into highly functional hepatocytes in 2D culture. Thus, Org-HEPs will be useful for pharmaceutical research, including hepatotoxicity tests.

Methyltransferase Like-3-Mediated N6-Methyladenosine Modification of Long Noncoding RNA Hepatocyte Nuclear Factor 1a Antisense RNA 1/Hepatocyte Nuclear Factor 4a Antisense RNA 1 Regulates Cytochrome P450 Enzyme Expression

Interindividual variations in the expression and activity of cytochrome P450 enzymes (CYPs) led to lower therapeutic efficacy or adverse drug events. We previously demonstrated that CYPs are regulated by the long noncoding RNAs (lncRNAs) hepatocyte nuclear factor 1a antisense RNA 1 (HNF1A-AS1) and HNF4A-AS1 via transcription factors (TFs) including hepatocyte nuclear factor 1a (HNF1A), hepatocyte nuclear factor 4a (HNF4A), and pregnane X receptor (PXR). However, the upstream mechanisms regulating HNF1A-AS1 and HNF4A-AS1 are poorly understood. N6-methyladenosine (m6A) is a prevalent epitranscriptomic modification in mammalian RNA. Therefore, the aim of this study was to investigate whether m6A modification regulates the expression of HNF1A-AS1 and HNF4A-AS1 and affects CYP expression in HepG2 and Huh7 cells. The methyltransferase-like 3 (METTL3) inhibitor, STM2457, significantly suppressed the expression of HNF1A-AS1 and induced HNF4A-AS1 expression. Consistent with this, a loss-of-function assay of METTL3 in the cell lines resulted in the downregulation of HNF1A-AS1 and its downstream HNF1A, PXR, and CYPs at the RNA level, as well as the downregulation of some CYPs proteins, and upregulation of HNF4A-AS1. The results of gain-of-function experiments showed the opposite trend. Mechanistically, subsequent RNA stability experiments confirmed that METTL3 affected the stability of both lncRNAs, but in opposite ways; that is, METTL3 reduced HNF1A-AS1 stability and increased HNF4A-AS1 stability. Rescue experiments confirmed that the regulation of METTL3 on TFs and CYPs may require the involvement of these two lncRNAs. Altogether, our study demonstrates that METTL3 is involved in TFs-mediated CYP expression by affecting HNF1A-AS1/HNF4A-AS1 stability. SIGNIFICANCE STATEMENT: Although the impact of long noncoding RNAs (lncRNAs) including hepatocyte nuclear factor 1a antisense RNA 1 (HNF1A-AS1) and hepatocyte nuclear factor 4a antisense RNA 1 (HNF4A-AS1) on the downstream transcription factor (TF) and cytochrome P450 enzyme (CYP) expression is well studied, the upstream regulation of these two lncRNAs by methyltransferase-like 3 (METTL3) remains unexplored. This study reveals that METTL3 is involved in the regulation of lncRNA-TF-CYP expression by affecting the stability of HNF1A-AS1 and HNF4A-AS1 in HepG2 and Huh7 cells.

Fumonisin B1 induces endoplasmic reticulum damage and inflammation by activating the NXR response and disrupting the normal CYP450 system, leading to liver damage in juvenile quail

Fumonisin B1 (FB1) is a mycotoxin affecting animal health through the food chain and has been closely associated with several diseases such as pulmonary edema in pigs and diarrhea in poultry. FB1 is mainly metabolized in the liver. Although a few studies have shown that FB1 causes liver damage, the molecular mechanism of liver damage is unclear. This study aimed to evaluate the role of liver damage, nuclear xenobiotic receptor (NXR) response and cytochrome P450 (CYP450)-mediated defense response during FB1 exposure. A total of 120 young quails were equally divided into two groups (control and FB1 groups). The quails in the control group were fed on a normal diet, while those in the FB1 group were fed on a quail diet containing 30 mg/kg for 42 days. Histopathological and ultrastructural changes in the liver, biochemical parameters, inflammatory factors, endoplasmic reticulum (ER) factors, NXR response and CYP450 cluster system and other related genes were examined at 14 days, 28 days and 42 days. The results showed that FB1 exposure impaired the metabolic function and caused liver injury. FB1 caused ER stress and decreased adenosine triphosphatease activity, induced the expression of inflammation-related genes such as interleukin 6 and nuclear factor kappa-B, and promoted inflammation. In addition, FB1 disrupted the expression of multiple CYP450 isoforms by activating nuclear xenobiotic receptors (NXRs). The present study confirms that FB1 exposure disturbs the homeostasis of cytochrome P450 systems (CYP450s) in quail liver by activating NXR responses and thereby causing liver damage. This study's findings provide insight into the molecular mechanisms of FB1-induced hepatotoxicity.

Functional assessment of CYP3A4 and CYP2C19 genetic polymorphisms on the metabolism of clothianidin invitro

Clothianidin, classified as a second-generation neonicotinoid, has achieved extensive application due to its high efficacy against insect pests. This broad-spectrum usage has resulted in its frequent detection in environmental surveys. CYP2C19 and CYP3A4 are crucial for converting clothianidin to desmethyl-clothianidin (dm-clothianidin). The expression of these CYP450s can be significantly influenced by genetic polymorphisms. The objective of our research was to examine the catalytic effects of 27 CYP3A4 variants and 31 CYP2C19 variants on the metabolism of clothianidin within recombinant insect microsomes. These variants were assessed through a well-established incubation procedure. In addition, the concentration of its metabolite dm-clothianidin was quantified by employing an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Lastly, the kinetic parameters of these CYP3A4 and CYP2C19 variants were calculated by applying Michaelis-Menten kinetic analysis to fit the data. The observed changes in enzyme activity were related to the metabolic transformation of clothianidin to dm-clothianidin. In the CYP2C19 metabolic pathway, one variant (CYP2C19.23) showed no notable change in intrinsic clearance (CLint), four variants (CYP2C19.29, .30, .31 and L16F) demonstrated a marked increase in CLint (110.86-183.46 %), and the remaining 25 variants exhibited a considerable decrease in CLint (26.38-89.79 %), with a maximum decrease of 73.62 % (CYP2C19.6). In the CYP3A4 metabolic pathway, 26 variants demonstrated significantly reduced CLint (10.54-52.52 %), with a maximum decrease of 89.46 % (CYP3A4.20). Our results suggested that most variants of CYP3A4 and CYP2C19 significantly altered the enzymatic activities associated with clothianidin metabolism to various degrees. This study provides new insights into assessing the metabolic behavior of pesticides and delivers crucial data that can guide clinical detoxification strategies.

Investigating the Correlation between Genotypes and Hepatic Protein Expression of CYP2C9, CYP2C19, CYP2D6, and CYP3A5 Using Postmortem Tissue from a Danish Population

The cytochrome P450 (CYP) family of enzymes plays a central role in the metabolism of many drugs. CYP genes are highly polymorphic, which is known to affect protein levels, but for some low frequent CYP genotypes the correlation between genotype and CYP protein expression is less established. In this study, we determined the CYP2C9, CYP2C19, CYP2D6, and CYP3A5 genotypes of 250 Danish individuals included in a postmortem study. For 116 of the individuals, the hepatic CYP protein levels were investigated by a proteomics approach. Overall, we found the postmortem genetic and proteomic data to be in agreement with those of other studies performed on fresh hepatic tissue, showing the usability of postmortem hepatic tissue for this type of investigation. For less investigated genotypes, we could corroborate previously found results: 1) statistically significantly lower levels of hepatic CYP2C9 protein in individuals carrying the CYP2C9*3 variant compared with individuals with two wild type (wt) alleles; 2) comparable levels of CYP2C19 in CYP2C19*2/*17 and CYP2C19*1/*2 individuals; 3) reduced CYP2D6 protein levels in heterozygous individuals with the CYP2D6*3, CYP2D6*4, and CYP2D6*5 gene deletion variants; and 4) significantly lower levels of CYP3A5 protein in CYP3A5*3 homozygous individuals compared with individuals who were heterozygous for the CYP3A5*3 allele or homozygous individuals for the wt alleles. In conclusion, the use of postmortem tissue significantly increases the access to human specimens for research purposes, and postmortem proteomics can be used to investigate the link between CYP genotypes and hepatic protein expression. SIGNIFICANCE STATEMENT: In tissue samples from a large postmortem cohort (n = 250) we determined the CYP2C9, CYP2C19, CYP2D6, and CYP3A5 genotypes. Hepatic CYP protein levels were investigated in 116 individuals using a proteomics approach. For common genotypes, we found results similar to previous knowledge, pointing toward the usability of postmortem tissue. For the less investigated genotypes, we were able to corroborate genotype/protein expression correlations. It is a novel approach to use a large postmortem cohort to investigate genetic/protein expression correlations.

The Diversity of CYP2C19 Polymorphisms in the Thai Population: Implications for Precision Medicine

Introduction

CYP2C19 plays a major role in the metabolism of various drugs. The most common genetic variants were the CYP2C19*2 and *3 alleles (rs4244285 and rs4986893, non-functional variants). In previous studies, we found that genetic polymorphisms in CYP2C19 variants influenced the active metabolites of clopidogrel and caused major adverse cardiovascular and cerebrovascular effects. However, the distribution of CYP2C19 varies among ethnic groups and according to adverse drug reactions. This study aimed to investigate the frequency of CYP2C19 genetic polymorphisms in the Thai population and analyze the differences in the frequency of CYP2C19 genetic polymorphisms between Thai and other populations.

Methods

This study enrolled 211 unrelated healthy Thai individuals in total. We performed a real-time polymerase chain reaction to genotype CYP2C19*2 (681G > A) and CYP2C19*3 (636G > A).

Results

In the Thai population, the CYP2C19*1 allele was the most prevalent at 70.14%, while the CYP2C19*2 and *3 alleles were found at frequencies of 25.36% and 4.50%, respectively. Conversely, the CYP2C19*3 allele was not detected in Caucasian, Hispanic, African, Italian, Macedonian, Tanzanian, or North Indian populations. The phenotypic profile of this gene revealed that the frequency of intermediate metabolizers (IMs) is nearly equal to that of extensive metabolizers (EMs), at 42.65% and 48.82% respectively, with genotypes *1/*2 (36.02%) and *1/*3 (6.63%). Likewise, poor metabolizers (PMs) with genotypes *2/*2 (6.16%), *2/*3 (2.37%), and *3/*3 (<1%) are more prevalent in our population as well.

Conclusion

The distribution of CYP2C19 genotype and phenotype influenced by non-functional alleles has potential as a pharmacogenomics biomarker for precision medicine and is dependent on an ethnic-specific genetic variation database.

Decoding the Role of CYP450 Enzymes in Metabolism and Disease: A Comprehensive Review

Cytochrome P450 (CYP450) is a group of enzymes that play an essential role in Phase I metabolism, with 57 functional genes classified into 18 families in the human genome, of which the CYP1, CYP2, and CYP3 families are prominent. Beyond drug metabolism, CYP enzymes metabolize endogenous compounds such as lipids, proteins, and hormones to maintain physiological homeostasis. Thus, dysregulation of CYP450 enzymes can lead to different endocrine disorders. Moreover, CYP450 enzymes significantly contribute to fatty acid metabolism, cholesterol synthesis, and bile acid biosynthesis, impacting cellular physiology and disease pathogenesis. Their diverse functions emphasize their therapeutic potential in managing hypercholesterolemia and neurodegenerative diseases. Additionally, CYP450 enzymes are implicated in the onset and development of illnesses such as cancer, influencing chemotherapy outcomes. Assessment of CYP450 enzyme expression and activity aids in evaluating liver health state and differentiating between liver diseases, guiding therapeutic decisions, and optimizing drug efficacy. Understanding the roles of CYP450 enzymes and the clinical effect of their genetic polymorphisms is crucial for developing personalized therapeutic strategies and enhancing drug responses in diverse patient populations.

Effect of eugenol on cytochrome P450 1A2, 2C9, 2D6, and 3A4 activity in human liver microsomes

This study aimed to provide an understanding of the influence of eugenol on CYP1A2, 2C9, 2D6, and 3A4 in human liver microsomes (HLM). Specific substrate for CYP1A2, 2C9, 2D6, and 3A4 were incubated in HLM with or without eugenol. The formation of their respective metabolites was assessed with HPLC analytical methods. Eugenol at 1, 10 and 100 µM levels inhibited the activity of CYP1A2 and CYP2C9 by 23.38 %, 23.57 %, 39.80 % and 62.82 %, 63.27 %, 67.70 % respectively. While, CYP2D6 and CYP3A4 activity was decreased by 40.70 %, 45.88 %, 62.68 % and 37.41 %, 42.58 % and 67.86 % at 1, 10 and 100 µM eugenol level respectively. The IC50 value of eugenol for CYP2D6 and CYP3A4 was calculated as 11.09 ± 3.49 µM and 13.48 ± 3.86 µM respectively. Potential herb-drug interactions was noted when eugenol is administered simultaneously with medications metabolized by these enzymes, most notably CYP2C9, CYP2D6 and CYP3A4.

Electrochemical Synthesis of the In Human S-oxide Metabolites of Phenothiazine-Containing Antipsychotic Medications

The tractable preparation of Phase I drug metabolites is a critical step to understand the first-pass behaviour of novel chemical entities (NCEs) in drug discovery. In this study, we have developed a structure-electroactivity relationship (SeAR)-informed electrochemical reaction of the parent 2-chlorophenothiazine and the antipsychotic medication, chlorpromazine. With the ability to dial-in under current controlled conditions, the formation of S-oxide and novel S,S-dioxide metabolites has been achieved for the first time on a multi-milligram scale using a direct batch electrode platform. A potential rationale for the electrochemical formation of these metabolites in situ is proposed using molecular docking to a cytochrome P450 enzyme.

Genetic Variability of CYP4F2, CYP2D6, CYP2E1, and ACE in the Chinese Yi Population

Genetic polymorphisms of very important pharmacogenes (VIP) are a significant factor contributing to inter-individual variability in drug therapy. The purpose of this study was to identify significantly different loci in the Yi population and to enrich their pharmacogenomic information. 54 VIP variants were selected from the Pharmacogenomics Knowledge Base (PharmGKB) and genotyped in 200 Yi individuals. Then, we compared their genotype distribution between the Yi population and the other 26 populations using the χ2 test. Compared with the other 26 populations, the genotype frequencies of 4 single nucleotide polymorphisms (SNPs), rs2108622 (CYP4F2), rs1065852 (CYP2D6), rs2070676 (CYP2E1), and rs4291 (ACE), had significant differences in the Yi population. For example, the TT genotype frequency of rs2108622 (8.1%) was higher than that of African populations, and the AA genotype frequency of rs1065852 (27.3%) was higher than that of other populations except East Asians. We also found that the Yi populations differed the least from East Asians and the most from Africans. Furthermore, the differences in these variants might be related to the effectiveness and toxicity risk of using warfarin, iloperidone, cisplatin cyclophosphamide, and other drugs in the Yi population. Our data complement the pharmacogenomic information of the Yi population and provide theoretical guidance for their personalized treatment.

Designing cytochrome P450 enzymes for use in cancer gene therapy

Cancer is a significant global socioeconomic burden, as millions of new cases and deaths occur annually. In 2020, almost 10 million cancer deaths were recorded worldwide. Advancements in cancer gene therapy have revolutionized the landscape of cancer treatment. An approach with promising potential for cancer gene therapy is introducing genes to cancer cells that encode for chemotherapy prodrug metabolizing enzymes, such as Cytochrome P450 (CYP) enzymes, which can contribute to the effective elimination of cancer cells. This can be achieved through gene-directed enzyme prodrug therapy (GDEPT). CYP enzymes can be genetically engineered to improve anticancer prodrug conversion to its active metabolites and to minimize chemotherapy side effects by reducing the prodrug dosage. Rational design, directed evolution, and phylogenetic methods are some approaches to developing tailored CYP enzymes for cancer therapy. Here, we provide a compilation of genetic modifications performed on CYP enzymes aiming to build highly efficient therapeutic genes capable of bio-activating different chemotherapeutic prodrugs. Additionally, this review summarizes promising preclinical and clinical trials highlighting engineered CYP enzymes' potential in GDEPT. Finally, the challenges, limitations, and future directions of using CYP enzymes for GDEPT in cancer gene therapy are discussed.

Genome-wide association study reveals shared and distinct genetic architecture underlying fatty acid and bioactive oxylipin metabolites in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Bioactive fatty acid-derived oxylipin molecules play key roles in mediating inflammation and oxidative stress, which underlie many chronic diseases. Circulating levels of fatty acids and oxylipins are influenced by both environmental and genetic factors; characterizing the genetic architecture of bioactive lipids could yield new insights into underlying biological pathways. Thus, we performed a genome wide association study (GWAS) of n=81 fatty acids and oxylipins in n=11,584 Hispanic Community Health Study/Study of Latinos (HCHS/SOL) participants with genetic and lipidomic data measured at study baseline (58.6% female, mean age = 46.1 years, standard deviation = 13.8 years). Additionally, given the effects of central obesity on inflammation, we examined interactions with waist circumference using two-degree-of-freedom joint tests. Heritability estimates ranged from 0% to 47.9%, and 48 of the 81oxylipins and fatty acids were significantly heritable. Moreover, 40 (49.4%) of the 81 oxylipins and fatty acids had at least one genome-wide significant (p< 6.94E-11) variant resulting in 19 independent genetic loci involved in fatty acid and oxylipin synthesis, as well as downstream pathways. Four loci (lead variant minor allele frequency [MAF] range: 0.08-0.50), including the desaturase-encoding FADS and the OATP1B1 transporter protein-encoding SLCO1B1, exhibited associations with four or more fatty acids and oxylipins. The majority of the 15 remaining loci (87.5%) (lead variant MAF range = 0.03-0.45, mean = 0.23) were only associated with one oxylipin or fatty acid, demonstrating evidence of distinct genetic effects. Finally, while most loci identified in two-degree-of-freedom tests were previously identified in our main effects analyses, we also identified an additional rare variant (MAF = 0.002) near CARS2, a locus previously implicated in inflammation. Our analyses revealed shared and distinct genetic architecture underlying fatty acids and oxylipins, providing insights into genetic factors and motivating future multi-omics work to characterize these compounds and elucidate their roles in disease pathways.

Opioid analgesics for nociceptive cancer pain: A comprehensive review

Pain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo-controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate-certainty to low-certainty evidence). Nonsteroidal anti-inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate-to-severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.

Complete correction of murine phenylketonuria by selection-enhanced hepatocyte transplantation

BACKGROUND AND AIMS

Hepatocyte transplantation for genetic liver diseases has several potential advantages over gene therapy. However, the low efficiency of cell engraftment has limited its clinical implementation. This problem could be overcome by selectively expanding transplanted donor cells until they replace enough of the liver mass to achieve therapeutic benefit. We previously described a gene therapy method to selectively expand hepatocytes deficient in cytochrome p450 reductase (Cypor) using acetaminophen (APAP). Because Cypor is required for the transformation of APAP to a hepatotoxic metabolite, Cypor-deficient cells are protected from toxicity and are able to expand following APAP-induced liver injury. Here, we apply this selection system to correct a mouse model of phenylketonuria by cell transplantation.

APPROACH AND RESULTS

Hepatocytes from a wild-type donor animal were edited in vitro to create Cypor deficiency and then transplanted into phenylketonuric animals. Following selection with APAP, blood phenylalanine concentrations were fully normalized and remained stable following APAP withdrawal. Cypor-deficient hepatocytes expanded from < 1% to ~14% in corrected animals, and they showed no abnormalities in blood chemistries, liver histology, or drug metabolism.

CONCLUSIONS

We conclude that APAP-mediated selection of transplanted hepatocytes is a potential therapeutic for phenylketonuria with long-term efficacy and a favorable safety profile.

Pleiotropy of Progesterone Receptor Membrane Component 1 in Modulation of Cytochrome P450 Activity

Progesterone receptor membrane component 1 (PGRMC1) is one of few proteins that have been recently described as direct modulators of the activity of human cytochrome P450 enzymes (CYP)s. These enzymes form a superfamily of membrane-bound hemoproteins that metabolize a wide variety of physiological, dietary, environmental, and pharmacological compounds. Modulation of CYP activity impacts the detoxification of xenobiotics as well as endogenous pathways such as steroid and fatty acid metabolism, thus playing a central role in homeostasis. This review is focused on nine main topics that include the most relevant aspects of past and current PGRMC1 research, focusing on its role in CYP-mediated drug metabolism. Firstly, a general overview of the main aspects of xenobiotic metabolism is presented (I), followed by an overview of the role of the CYP enzymatic complex (IIa), a section on human disorders associated with defects in CYP enzyme complex activity (IIb), and a brief account of cytochrome b5 (cyt b5)'s effect on CYP activity (IIc). Subsequently, we present a background overview of the history of the molecular characterization of PGRMC1 (III), regarding its structure, expression, and intracellular location (IIIa), and its heme-binding capability and dimerization (IIIb). The next section reflects the different effects PGRMC1 may have on CYP activity (IV), presenting a description of studies on the direct effects on CYP activity (IVa), and a summary of pathways in which PGRMC1's involvement may indirectly affect CYP activity (IVb). The last section of the review is focused on the current challenges of research on the effect of PGRMC1 on CYP activity (V), presenting some future perspectives of research in the field (VI).

CYP2D6 Phenotype Influences Pharmacokinetic Parameters of Venlafaxine: Results from a Population Pharmacokinetic Model in Older Adults with Depression

In this study, we aimed to improve upon a published population pharmacokinetic (PK) model for venlafaxine (VEN) in the treatment of depression in older adults, then investigate whether CYP2D6 metabolizer status affected model-estimated PK parameters of VEN and its active metabolite O-desmethylvenlafaxine. The model included 325 participants from a clinical trial in which older adults with depression were treated with open-label VEN (maximum 300 mg/day) for 12 weeks and plasma levels of VEN and O-desmethylvenlafaxine were assessed at weeks 4 and 12. We fitted a nonlinear mixed-effect PK model using NONMEM to estimate PK parameters for VEN and O-desmethylvenlafaxine adjusted for CYP2D6 metabolizer status and age. At both lower doses (up to 150 mg/day) and higher doses (up to 300 mg/day), CYP2D6 metabolizers impacted PK model-estimated VEN clearance, VEN exposure, and active moiety (VEN + O-desmethylvenlafaxine) exposure. Specifically, compared with CYP2D6 normal metabolizers, (i) CYP2D6 ultra-rapid metabolizers had higher VEN clearance; (ii) CYP2D6 intermediate metabolizers had lower VEN clearance; (iii) CYP2D6 poor metabolizers had lower VEN clearance, higher VEN exposure, and higher active moiety exposure. Overall, our study showed that including a pharmacogenetic factor in a population PK model could increase model fit, and this improved model demonstrated how CYP2D6 metabolizer status affected VEN-related PK parameters, highlighting the importance of genetic factors in personalized medicine.

Genetic polymorphisms of CYP2C19 in ecuadorian population: An interethnic approach

Introduction

CYP2C19 is a highly polymorphic gene responsible for metabolizing commonly used drugs. CYP2C19*2,*3 (loss of activity alleles) and *17 (increased activity allele) are the principal alleles included in clinical guidelines, however their prevalence varies among different ethnicities. Ecuadorian population is formed by Mestizos, Afrodescendants and Native Americans and frequency of CYP2C19 alleles could be different among them. The objective of this study was to establish the frequency of these variants in the different populations of Ecuador and to compare them with other populations.

Materials and methods

DNA from 105 Afrodescendants, 75 Native Americans of the Kichwa ethnicity, and 33 Mestizos Ecuadorians was analyzed by nested-PCR to identify CYP2C19*17 carriers. CYP2C19*2 allele was analyzed in DNA from 78 Afrodescendants, 29 Native Americans of the Kichwa, and 16 Mestizos by TaqMan Allelic Discrimination Assay. CYP2C19*3 was analyzed in 33 Afrodescendants by nested-PCR.

Results

The global frequencies of the alternate alleles were 14.22% (CYP2C19*2) and 2.10% (CYP2C19*17). No differences (p > 0.05) were observed among the subgroups. No CYP2C19*3 carrier was identified. CYP2C19*2 frequencies in Ecuador were similar to the ones reported in Europe, Africa and Middle East countries and to some American populations. Low CYP2C19*17 frequencies, like the ones in our population, were also observed in East and South Asia and in Native American groups.

Discussion

Absence of differences in the ethnic groups in Ecuador for CYP2C19*2 and *17 could be due to either a bias in sample selection (ethnic group was assed by self-identification) or to a high interethnic admixture in the Ecuadorian population that would had diluted genetic differences. In addition, CYP2C19*2, *3, and *17 alleles frequencies in our study suggest that Ecuadorians ancestry is mostly of Native American origin.

CBD and THC in Special Populations: Pharmacokinetics and Drug-Drug Interactions

Cannabinoid use has surged in the past decade, with a growing interest in expanding cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) applications into special populations. Consequently, the increased use of CBD and THC raises the risk of drug-drug interactions (DDIs). Nevertheless, DDIs for cannabinoids, especially in special populations, remain inadequately investigated. While some clinical trials have explored DDIs between therapeutic drugs like antiepileptic drugs and CBD/THC, more potential interactions remain to be examined. This review summarizes the published studies on CBD and THC-drug interactions, outlines the mechanisms involved, discusses the physiological considerations in pharmacokinetics (PK) and DDI studies in special populations (including pregnant and lactating women, pediatrics, older adults, patients with hepatic or renal impairments, and others), and presents modeling approaches that can describe the DDIs associated with CBD and THC in special populations. The PK of CBD and THC in special populations remain poorly characterized, with limited studies investigating DDIs involving CBD/THC in these populations. Therefore, it is critical to evaluate potential DDIs between CBD/THC and medications that are commonly used in special populations. Modeling approaches can aid in understanding these interactions.

Oxygen-dependent histone lysine demethylase 4 restricts hepatitis B virus replication

Mammalian cells have evolved strategies to regulate gene expression when oxygen is limited. Hypoxia-inducible factors (HIF) are the major transcriptional regulators of host gene expression. We previously reported that HIFs bind and activate hepatitis B virus (HBV) DNA transcription under low oxygen conditions; however, the global cellular response to low oxygen is mediated by a family of oxygenases that work in concert with HIFs. Recent studies have identified a role for chromatin modifiers in sensing cellular oxygen and orchestrating transcriptional responses, but their role in the HBV life cycle is as yet undefined. We demonstrated that histone lysine demethylase 4 (KDM4) can restrict HBV, and pharmacological or oxygen-mediated inhibition of the demethylase increases viral RNAs derived from both episomal and integrated copies of the viral genome. Sequencing studies demonstrated that KDM4 is a major regulator of the hepatic transcriptome, which defines hepatocellular permissivity to HBV infection. We propose a model where HBV exploits cellular oxygen sensors to replicate and persist in the liver. Understanding oxygen-dependent pathways that regulate HBV infection will facilitate the development of physiologically relevant cell-based models that support efficient HBV replication.

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.

Most patients with disorders of gut-brain interaction receive pharmacotherapy with major or moderate drug-gene interactions

BACKGROUND

How variations predicted by pharmacogenomic testing to alter drug metabolism and therapeutic response affect outcomes for patients with disorders of gut- brain interaction is unclear.

AIMS

To assess the prevalence of pharmacogenomics-predicted drug-gene interactions and symptom outcomes for patients with disorders of gut-brain interaction.

METHODS

Patients who were treated in our clinical practice for functional dyspepsia/bowel disorder underwent pharmacogenomic testing. The change in symptoms from baseline to 6 months was compared for patients with variations in CYP2D6 and CYP2C19, which metabolize neuromodulators, and SLC6A4, which encodes the sodium- dependent serotonin transporter.

RESULTS

At baseline, 79 of 94 participants (84%) had at least one predicted major drug- gene interaction, and all 94 (100%) had at least one predicted moderate interaction. For the 44 participants who completed a survey of their symptoms at 6 months, the mean (SD) irritable bowel syndrome-symptom severity score decreased from 284 (71) at baseline to 231 (95) at 6 months (p < 0.001). Among patients taking selective serotonin reuptake inhibitors, the decrease in symptom severity (p = 0.03) and pain (p = 0.002) scores from baseline to 6 months was greater for patients with a homozygous SLC6A4 long/long genotype (n = 30) (ie, increased serotonin transporter activity) than for patients with homozygous short/short or heterozygous long/short genotypes (n = 64). Symptom outcomes were not affected by CYP2D6 or CYP2C19 variations.

CONCLUSIONS

The homozygous SLC6A4 long/long genotype confers better symptom resolution for patients with disorders of gut-brain interaction who take selective serotonin reuptake inhibitors than do the homozygous short/short or heterozygous long/short genotypes.

Investigation of Drug-Interaction Potential for Arthritis Dietary Supplements: Chondroitin Sulfate, Glucosamine, and Methylsulfonylmethane

Osteoarthritis is one of the leading conditions that promote the consumption of these dietary supplements. Chondroitin sulfate, glucosamine, and methylsulfonylmethane are among the prominent alternative treatments for osteoarthritis. In this study, these dietary supplements were incubated with cytochrome P450 isozyme-specific substrates in human liver microsomes, and the formation of marker metabolites was measured to investigate their inhibitory potential on cytochrome P450 enzyme activities. The results revealed no significant inhibitory effects on seven CYPs, consistent with established related research data. Therefore, these substances are anticipated to have a low potential for cytochrome P450-mediated drug interactions with osteoarthritis medications that are likely to be co-administered. However, given the previous reports of interaction cases involving glucosamine, caution is advised regarding dietary supplement-drug interactions.

Metabolism of testosterone and progesterone by cytochrome P450 2C19 allelic variants

CYP2C19 is a member of the human microsomal cytochrome P450 (CYP). Significant variation in CYP2C19 levels and activity can be attributed to polymorphisms in this gene. Wildtype CYP2C19 and 13 mutants (CYP2C19.1B, CYP2C19.5A, CYP2C19.5B, CYP2C19.6, CYP2C19.8, CYP2C19.9, CYP2C19.10, CYP2C19.11, CYP2C19.13, CYP2C19.16, CYP2C19.19, CYP2C19.23, CYP2C19.30, and CYP2C19.33) were coexpressed with NADPH-cytochrome P450 reductase in Escherichia coli. Hydroxylase activity toward testosterone and progesterone was also examined. Ten CYP2C19 variants showed Soret peaks (450 nm) typical of P450 in the reduced CO-difference spectra. CYP2C19.11 and CYP2C19.23 showed higher testosterone 11α, 16α-/17- and progesterone 6β-,21-,16α-/17α-hydroxylase activities than CYP2C19.1B. CYP2C19.6, CYP2C19.16, CYP2C19.19, and CYP2C19.30 showed lower activity than CYP2C19.1B. CYP2C19.9, CYP2C19.10. CYP2C19.13, and CYP2C19.33 showed different hydroxylation activities than CYP2C19.1B. These results indicated that CYP2C19 variants have very different substrate specificities for testosterone and progesterone.

Pyrrolizidine Alkaloids-Pros and Cons for Pharmaceutical and Medical Applications

Heterocyclic organic compounds named pyrrolizidine alkaloids (PAs) belong to a group of alkaloids and are synthesized by either plants or microorganisms. Therefore, they are naturally occurring secondary metabolites. They are found in species applied in the pharmaceutical and food industries, thus a thorough knowledge of their pharmacological properties and toxicology to humans is of great importance for their further safe employment. This review is original because it synthesizes knowledge of plant and microbial PAs, which is unusual in the scientific literature. We have focused on the Boraginaceae family, which is unique due to the exceptional richness and diversity of its PAs in plant species. We have also presented the microbial sources of PAs, both from fungi and bacteria. The structure and metabolism of PAs have been discussed. Our main aim was to summarize the effects of PAs on humans, including both negative, toxic ones, mainly concerning hepatotoxicity and carcinogenicity, as well as potentially positive ones for pharmacological and medical applications. We have collected the results of studies on the anticancer activity of PAs from plant and microbial sources (mainly Streptomyces strains) and on the antimicrobial activity of PAs on different strains of microorganisms (bacteria and fungi). Finally, we have suggested potential applications and future perspectives.