Effects of cannabidiol and Δ9-tetrahydrocannabinol on cytochrome P450 enzymes: a systematic review

A drug-drug interaction (DDI) is a pharmacokinetic or pharmacological influence of 1 medication on another that differs from the known or anticipated effects of each agent alone.1 A DDI may result in a change in either drug efficacy or drug toxicity for 1 or both of the interacting medications.2 Pharmacokinetic DDIs result in altered absorption, distribution, metabolism, or excretion of a medication. A pharmacodynamic DDI occurs when 1 medication modifies the pharmacological effect of another in an additive, a synergistic, or an antagonistic fashion. It is estimated that ≈2.8% of hospital admissions occur as a direct result of DDIs.3 However, the actual incidence of hospitalization secondary to clinically significant DDIs is likely to be highly underestimated because medication-related issues are more commonly reported as adverse drug reactions. Complex underlying disease states also may make recognizing a DDI more challenging, further contributing to a lower reported incidence. The overall clinical impact of a DDI can range from mild to life-threatening. Therefore, not all DDIs require a modification in therapy. The variability in the clinical significance of a DDI depends on both medication-specific and patient-specific factors. Medication-specific factors include the individual pharmacokinetic characteristics of each medication implicated in the DDI (eg, binding affinity, half-life [t1/2]), dose of the medications, serum concentrations, timing and sequence of administration, and duration of therapy. Patient-specific factors include age, sex, lifestyle, genetic polymorphisms causing differences in enzyme expression or activity, and disease impairment affecting drug metabolism (eg, hepatic or renal impairment, cardiac failure) or predisposition to differences in efficacy or safety (eg, statin intolerance in patients with a history of myopathy). Clinically significant DDIs are usually preventable. To optimize patient safety, healthcare providers must have an understanding of the mechanisms, magnitude, and potential consequences of any given DDI. Interpreting this information …

HepaRG human hepatic cell line utility as a surrogate for primary human hepatocytes in drug metabolism assessment in vitro

Drug interactions have always been a major concern in medicine for clinicians and patients. Inhibition and induction of cytochrome P450 (CYP) enzymes are probably the most common causes for documented drug interactions. Today, many pharmaceutical companies are predicting potential interactions of new drug candidates. Can in vivo drug interactions be predicted accurately from in vitro metabolic studies? Should the prediction be qualitative or quantitative? Although some scientists believe that quantitative prediction of drug interactions is possible, others are less optimistic and believe that quantitative prediction would be very difficult. There are many factors that contribute to our inability to quantitatively predict drug interactions. One of the major complicating factors is the large interindividual variability in response to enzyme inhibition and induction. This review examines the sources that are responsible for the interindividual variability in inhibition and induction of cytochrome P450 enzymes.

Therapeutic proteins (TPs) may affect the disposition of drugs that are metabolized by cytochrome P450 (CYP) enzymes, as is evident from a review of data in recently published literature and approved Biologic License Applications. Many TPs belonging to the cytokine class appear to differentially affect CYP activities. Cytokine modulators may affect CYP enzyme activities by altering cytokine effects on CYP enzymes. The alteration in CYP enzyme activities seems to result from changes in transcription factor activity for CYP enzyme expression or changes in CYP enzyme stability, which have been observed during altered immunological states such as infection and inflammation. Human growth hormone also appears to differentially affect CYP activities through unknown mechanisms. Because TP-drug interaction research is an evolving area, limited information is available during drug development on TP-drug interactions mediated by CYP inhibition or induction. The authors of this review suggest that effort be made to understand TP-drug interactions for the safe and effective use of TPs in combination with small-molecule drugs.

The induction of drug-metabolizing enzymes is a special case of pharmacokinetic interactions with consequences for the concurrent drug therapy. The most important enzymes affecting the pharmacokinetics of pharmaceuticals are cytochrome P450 (CYP) enzymes and their induction is often of utmost importance for the effects of the metabolized drugs. This review presents the current knowledge on the inducers of the specific CYP enzymes in humans. The focus is solely on human in vivo findings; in vitro results are referenced only when needed to interpret the induction mechanisms. As the mechanisms of CYP induction are important in understanding the effects of inducers, a concise overview of the various receptors affecting the induction of human CYP enzymes is presented.

Evaluation potential effects of Picroside II on cytochrome P450 enzymes in vitro and in vivo

Induction of cytochrome P450 (CYP) enzymes is one of the major mechanisms for drug-drug interactions (DDIs), which requires accurate assessment for dose adjustments. This study aimed to develop a reliable method for isolating exosomes from rat and human plasma samples, quantifying several CYP enzymes in the isolated exosomes at the mRNA level, and further validating their utility for studying enzyme induction in both preclinical and clinical settings. We evaluated and validated exosome isolation methods from human plasma and serum samples using nanoparticle tracking analysis (NTA) for physical characterization and RT-qPCR for exosomal mRNA quantification. CYP mRNA induction was quantified in plasma-derived exosomes from rats and humans following dexamethasone or modafinil treatment. Among six exosome isolation methods, the ExoQuick kit was selected and further optimized based on the high yield and purity of isolated exosomes. This workflow of exosome isolation and RNA extraction exhibited high precision and reproducibility, and demonstrated excellent assay linearity, with gene detectability and expression levels increasing in a volume-dependent manner from 0.5, 1 and 2 mL plasma samples. Following dexamethasone treatment in rats, significant induction of Cyp3a23/3a1 mRNA was observed in both plasma-derived exosomes and liver tissues. Additionally, CYP3A4, CYP3A5 and CYP1A2 mRNA in human plasma-derived exosomes were induced in clinical studies following 200 mg and 400 mg modafinil administration. We present a robust workflow for detecting several CYP mRNAs in plasma-derived exosomes and demonstrate proof-of-concept induction in preclinical and clinical samples. However, larger prospective studies are required to validate clinical utility.

Cytochrome P450 (CYP) enzymes play a central role in the elimination of approximately 80% of all clinically used drugs. Differences in CYP enzyme activity between individuals can contribute to interindividual variability in exposure and, therefore, treatment outcome. In vivo CYP enzyme activity could be determined with phenotyping. Currently, (sub)therapeutic doses are used for in vivo phenotyping, which can lead to side effects. The use of microdoses (100 µg) for in vivo phenotyping for CYP enzymes could overcome the limitations associated with the use of (sub)therapeutic doses of substrates. The aim of this review is to provide a critical overview of the application of microdosing for in vivo phenotyping of CYP enzymes. A literature search was performed to find drug–drug interaction studies of CYP enzyme substrates that used microdoses of the respective substrates. A substrate was deemed sensitive to changes in CYP enzyme activity when the pharmacokinetics of the substrate significantly changed during inhibition and induction of the enzyme. On the basis of the currently available evidence, the use of microdosing for in vivo phenotyping for subtypes CYP1A2, CYP2C9, CYP2D6, and CYP2E1 is not recommended. Microdosing can be used for the in vivo phenotyping of CYP2C19 and CYP3A. The recommended microdose phenotyping test for CYP2C19 is measuring the omeprazole area-under-the-concentration-time curve over 24 h (AUC0–24) after administration of a single 100 µg dose. CYP3A activity could be best determined with a 0.1–75 µg dose of midazolam, and subsequently measuring AUC extrapolated to infinity (AUC∞) or clearance. Moreover, there are two metrics available for midazolam using a limited sampling strategy: AUC over 10 h (AUC0–10) and AUC from 2 to 4 h (AUC2–4).Supplementary InformationThe online version contains supplementary material available at 10.1007/s13318-024-00896-2.

Prescribing multiple medications predisposes to possibilities of occurrence of drug interactions. Various different terminology and ways exist to classify or arrange drug interactions. Drugs interact with other drugs, foods, beverages and herbs; outside or inside the body. Knowledge of In vitro interactions is essential to avoid loss of activity of drugs before administration. Although every theoretical drug interaction may not manifest in practice, drug interaction is a prominent cause of adverse or undesired events related to drug administration. Amongst the herbs, St. John’s wort has a potential of producing significant drug interactions due to its capacity to induce metabolism of number of drugs. In vivo interactions at pharmacokinetic level affect absorption, distribution, biotransformation or excretion of drugs. Induction or inhibition of cytochrome P450 (CYP450) enzymes forms a major basis of drug interactions. Induction of metabolism of a substrate drug leads to treatment failure. Inhibition of metabolism leads to serious interactions by aggravating toxicity of substrate drugs. As compared to induction, inhibition is a fairly rapid process, and number of precipitant drugs which inhibit the metabolism is much more than that of inducers. Role of drug transporters, especially P-glycoprotein (P-gp), in causation of drug interactions is being increasingly identified. P-gp affects absorption, distribution and excretion, and hence plays a major role in pharmacokinetic drug interactions. Additionally, P-gp works hand in hand with CYP450 enzymes. In pharmacodynamic interactions, the drugs synergise or antagonise the effect at the level of target of action. Clinically beneficial and reparative drug interactions are explored to obtain useful drug combinations. Extensive research has led to development of a large number of In vitro and In vivo methods to detect and predict drug interactions. Appropriate awareness and knowledge of possible drug interactions is crucial in prevention of drug interactions and their consequences.

Preclinical studies suggested that green tea or green tea catechins can modulate the activities of drug-metabolizing enzymes. We conducted this clinical study to determine the effect of repeated green tea catechin administration on human cytochrome P450 (CYP) enzyme activities. Forty-two healthy volunteers underwent a 4-week washout period by refraining from tea or tea-related products. At the end of the washout period, study participants received a cocktail of CYP metabolic probe drugs, including caffeine, dextromethorphan, losartan, and buspirone for assessing the activity of CYP1A2, CYP2D6, CYP2C9, and CYP3A4, respectively. Blood and urine samples before and 8 h after probe drug administration were collected to determine parent drug and metabolite concentrations for measurements of baseline CYP enzyme activities. Following the baseline evaluation, study participants underwent 4 weeks of green tea catechin intervention at a dose that contains 800 mg epigallocatechin gallate (EGCG) daily. The green tea catechin product was taken on an empty stomach to optimize the p.o. bioavailability of EGCG. The EGCG dose given in this study exceeded the amounts provided by average green tea consumption. Upon completion of the green tea catechin intervention, the postintervention CYP enzyme activities were evaluated as described above. There are large between-subject variations in CYP enzyme activities in healthy individuals. Four weeks of green tea catechin intervention did not alter the phenotypic indices of CYP1A2, CYP12D6, and CYP12C9, but resulted in a 20% increase (P = 0.01) in the area under the plasma buspirone concentration-time profile, suggesting a small reduction in CYP3A4 activity. We conclude that repeated green tea catechin administration is not likely to result in clinically significant effects on the disposition of drugs metabolized by CYP enzymes.

Although nano-copper is currently used extensively, the adverse effects on liver cytochrome P450 (CYP450) enzymes after oral exposure are not clear. In this study, we determined the effects and mechanisms of action of nano- and micro-copper on the expression and activity of CYP450 enzymes in rat liver. Rats were orally exposed to micro-copper (400 mg/kg), Cu ion (100 mg/kg), or nano-copper (100, 200 and 400 mg/kg) daily for seven consecutive days. Histopathological, inflammatory and oxidative stress were measured in the livers of all rats. The mRNA levels and activity of CYP450 enzymes, as well as the mRNA levels of select nuclear receptors, were determined. Exposure to nano-copper (400 mg/kg) induced significant oxidative stress and inflammation relative to the controls, indicated by increased levels of interleukin (IL)-2, IL-6, interferon (IFN)-γ, macrophage inflammatory protein (MIP-1), total antioxidant capacity (T-AOC), malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) after exposure. The levels of mRNA expression of pregnane X receptor (PXR), constitutive androstane receptor (CAR) and aryl hydrocarbon receptor (AHR) were significantly decreased in 400 mg/kg nano-copper treated rats. Nano-copper activated the expression of the NF-kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT)3 signaling pathways. Nano-copper decreased the mRNA expression and activity of CYP 1A2, 2C11, 2D6, 2E1 and 3A4 in a dose-dependent manner. The adverse effects of micro-copper are less severe than those of nano-copper on the CYP450 enzymes of rats after oral exposure. Ingestion of large amounts of nano-copper in animals severely affects the drug metabolism of the liver by inhibiting the expression of various CYP450 enzymes, which increases the risk of drug-drug interactions in animals.

Gene expression profiling in the liver of CD-1 mice to characterize the hepatotoxicity of triazole fungicides

Ginkgo biloba Extract Markedly Induces Pentoxyresorufin O-Dealkylase Activity in Rats

The cytochrome P450 (CYP) enzymes are membrane-bound hemoproteins that play a pivotal role in the detoxification of xenobiotics, cellular metabolism and homeostasis. Induction or inhibition of CYP enzymes is a major mechanism that underlies drug-drug interactions. CYP enzymes can be transcriptionally activated by various xenobiotics and endogenous substrates through receptor-dependent mechanisms. CYP enzyme inhibition is a principal mechanism for metabolism- based drug-drug interactions. Many chemotherapeutic drugs can cause drug interactions due to their ability to either inhibit or induce the CYP enzyme system. Predictions based on in silico analyses followed by validation have identified several microRNAs that regulate CYPs. Genetic polymorphisms and epigenetic changes in CYP genes may be responsible for inter-individual and interethnic variations in disease susceptibility and the therapeutic efficacy of drugs. The present review is a comprehensive compilation of cytochrome P450 structure, function, pharmacogenetics, pharmacoepigenetics and clinical significance. Knowledge about the substrates, inducers, and inhibitors of CYP isoforms, as well as the polymorphisms of CYP enzymes may be used as an aid by clinicians to determine therapeutic strategy, and treatment doses for drugs that are metabolized by CYP gene products.

Immunochemical Analysis of Liver Microsomal Cytochromes P450 of the American Alligator, Alligator mississippiensis