Cytochrome P450 2C19 inhibitory activity of common berry constituents

Implementing pharmacogenetic testing to optimize proton-pump inhibitors use among Indian population based on CPIC-CYP2C19-PPI dosing guidelines: The need of the hour

ABSTRACT

Proton-pump inhibitors (PPIs) are widely prescribed to decrease stomach acid and treat various acid-related Gastrointestinal tract (GIT) diseases. However, genetic variations, particularly in the CYP2C19 gene, affect PPIs metabolism and efficacy. Variants in CYP2C19 can result in different rates of PPI metabolism, influencing their effectiveness. Personalized medicine strategies, such as genotyping for CYP2C19, have the potential to enhance the effectiveness of PPI therapy and patient safety. This review aims to describe the relevance of CYP2C19 genetic profiling in the indian population, including normal function (e.g. CYP2C19*1, *11, *13, *15, *18, *28, and 38), decreased function (e.g., CYP2C19*9, *10, *16, *19, *25, and 26), loss of function (e.g., CYP2C19*2, *3, *4, *5, *6, *7, *8, *22, *24, *35, *36, and *37), and increased function (e.g., CYP2C19*17) variants. This review also examines the clinical pharmacogenomics implementation consortium (CPIC)-CYP2C19-PPI guidelines to highlight the importance of pharmacogenomics (PGx)-informed personalized PPI therapy for gastroesophageal reflux disease and peptic ulcer disease treatment. On average, each person in India possesses eight pharmacogenetic (PGx) variants that can be clinically significant, underscoring the need for preemptive testing. Implementing CYP2C19 genetic testing in India requires expanding laboratory capacity, increasing accessibility in primary care, increasing public awareness, collaboration between pharmacovigilance and PGx programs, investing in advanced sequencing technologies, data management systems, and integration with electronic health records and clinical decision support systems. Addressing challenges such as genetic diversity, socioeconomic factors, health-care access issues, and shortage of trained professionals is essential for implementation. Due to the lack of definitive country-specific policies and PGx guidelines from Indian drug regulatory agencies, guidelines from international consortia such as the Clinical Pharmacogenetics Implementation Consortium and drug labeling offer crucial foundational evidence. This evidence can be used to enhance patient outcomes and ensure the safe and effective use of PPIs in India.

Enteral Medication for the Tube-Fed Patient: Making This Route Safe and Effective

The administration of medication through an enteral access device requires important forethought. Meeting a patient's therapeutic needs requires achieving expected drug bioavailability without increasing the risk for toxicity, therapeutic failure, or feeding tube occlusion. Superimposing gut dysfunction, critical illness, or enteral nutrition-drug interaction further increases the need for a systematic approach to prescribing, evaluating, and preparing a drug for administration through an enteral access device. This review will explain the fundamental factors involved in drug bioavailability through the gut, address the influencing considerations for the enterally fed patient, and describe best practices for enteral drug preparation and administration.

Potential inhibition of major human cytochrome P450 isoenzymes by selected tropical medicinal herbs-Implication for herb-drug interactions

BACKGROUND

Increasing use of medicinal herbs as nutritional supplements and traditional medicines for the treatment of diabetes, hypertension, hyperlipidemia, and malaria fever with conventional drugs poses possibilities of herb-drug interactions (HDIs). The potential of nine selected widely used tropical medicinal herbs in inhibiting human cytochrome P450 (CYP) isoenzymes was investigated.

MATERIALS AND METHODS

In vitro inhibition of eight major CYP isoenzymes by aqueous extracts of Allium sativum, Gongronema latifolium, Moringa oleifera, Musa sapientum, Mangifera indica, Tetracarpidium conophorum, Alstonia boonei, Bauhinia monandra, and Picralima nitida was estimated in human liver microsomes by monitoring twelve probe metabolites of nine probe substrates with UPLC/MS-MS using validated N-in-one assay method.

RESULTS

Mangifera indica moderately inhibited CYP2C8, CYP2B6, CYP2D6, CYP1A2, and CYP2C9 with IC 50 values of 37.93, 57.83, 67.39, 54.83, and 107.48 μg/ml, respectively, and Alstonia boonei inhibited CYP2D6 (IC 50 = 77.19 μg/ml). Picralima nitida inhibited CYP3A4 (IC 50 = 45.58 μg/ml) and CYP2C19 (IC 50 = 73.06 μg/ml) moderately but strongly inhibited CYP2D6 (IC 50 = 1.19 μg/ml). Other aqueous extracts of Gongronema latifolium, Bauhinia monandra, and Moringa oleifera showed weak inhibitory activities against CYP1A2. Musa sapientum, Allium sativum, and Tetracarpidium conophorum did not inhibit the CYP isoenzymes investigated.

CONCLUSION

Potential for clinically important CYP-metabolism-mediated HDIs is possible for Alstonia boonei, Mangifera indica, and Picralima nitida with drugs metabolized by CYP 2C8, 2B6, 2D6, 1A2, 2C9, 2C19, and 3A4. Inhibition of CYP2D6 by Picralima nitida is of particular concern and needs immediate in vivo investigations.

Effects of tomato juice on the pharmacokinetics of CYP3A4-substrate drugs

We previously demonstrated that tomato juice (TJ) contains potent mechanism-based inhibitor(s) of CYP3A4. In this study, we investigated the effects of TJ and grapefruit juice (GFJ) on the pharmacokinetics of the CYP3A4-substrate drugs, nifedipine (NFP) and midazolam (MDZ), in male Wistar rats. Oral administration of GFJ 90 min before the intraduodenal administration of NFP or MDZ increased the area under the concentration–time curves (AUCs) of NFP and MDZ by 32.4% and 89.4%, respectively. TJ increased MDZ blood concentrations and AUC after intraduodenal MDZ administration; however, it had no effect on NFP. When MDZ and NFP were intravenously administered, GFJ significantly increased the AUC of MDZ, but only slightly increased that of NFP. In contrast, TJ only slightly increased the AUC of MDZ. These results suggest that, similar to GFJ, TJ influences the pharmacokinetics of CYP3A4-substrate drugs; however, it may be a drug-dependent partial effect.

Rosehip inhibits xanthine oxidase activity and reduces serum urate levels in a mouse model of hyperuricemia

Rosehip, the fruit of Rosa canina L., has traditionally been used to treat urate metabolism disorders; however, its effects on such disorders have not been characterized in detail. Therefore, the present study investigated the effects of hot water, ethanol and ethyl acetate extracts of rosehip on xanthine oxidase (XO) activity in vitro. In addition, the serum urate lowering effects of the rosehip hot water extract in a mouse model of hyperuricemia (male ddY mice, which were intraperitoneally injected with potassium oxonate) were investigated. Furthermore, the influence of rosehip hot water extract on CYP3A4 activity, which is the most important drug-metabolizing enzyme from a herb-drug interaction perspective, was investigated. Rosehip extracts of hot water, ethanol and ethyl acetate inhibited XO activity [half maximal inhibitory concentration (IC50) values: 259.6±50.6, 242.5±46.2 and 1,462.8±544.2 µg/ml, respectively]. Furthermore, the administration of 1X rosehip hot water extract significantly reduced the levels of serum urate at 8 h, which was similar when compared with the administration of 1 mg/kg allopurinol. Rosehip hot water extract only marginally affected CYP3A4 activity (IC50 value, >1 mg/ml). These findings indicate that rosehip hot water extract may present as a functional food for individuals with a high urate level, and as a therapeutic reagent for hyperuricemic patients.

Inhibition of Human Cytochrome P450 Enzymes by Allergen Removed Rhus verniciflua Stoke Standardized Extract and Constituents

Objective. Potential interactions between herbal extracts and the cytochrome P450 (CYP) system lead to serious adverse events or decreased drug efficacy. Rhus verniciflua stoke (RVS) and its constituents have been reported to have various pharmacological properties. We evaluated the inhibitory potential of RVS and its constituents on the major CYP isoforms. Methods. The effects of allergen removed RVS (aRVS) standardized extract and major components, fustin and fisetin isolated from aRVS, were evaluated on CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 isoenzyme activity by a luminescent CYP recombinant human enzyme assay. Results. The aRVS extract showed relative potent inhibitory effects on the CYP2C9 (IC50, <0.001 μg/mL), CYP2C19 (IC50, 9.68 μg/mL), and CYP1A2 (IC50, 10.0 μg/mL). However, it showed weak inhibition on CYP3A4 and CYP2D6. Fustin showed moderate inhibitory effects on the CYP2C19 (IC50, 64.3 μg/mL) and weak inhibition of the other CYP isoforms similar to aRVS. Fisetin showed potent inhibitory effects on CYP2C9, CYP2C19, and CYP1A2. Fisetin showed moderate inhibition of CYP2D6 and weak inhibition of CYP3A4. Conclusions. These results indicate that aRVS, a clinically available herbal medicine, could contribute to herb-drug interactions when orally coadministered with drugs metabolized by CYP2C9, CYP2C19, and CYP1A2.

Effect of honokiol on cytochrome P450 and UDP-glucuronosyltransferase enzyme activities in human liver microsomes

Honokiol is a bioactive component isolated from the medicinal herbs Magnolia officinalis and Magnolia grandiflora that has antioxidative, anti-inflammatory, antithrombotic, and antitumor activities. The inhibitory potentials of honokiol on eight major human cytochrome P450 (CYP) enzymes 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4, and four UDP-glucuronosyltransferases (UGTs) 1A1, 1A4, 1A9, and 2B7 in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. Honokiol strongly inhibited CYP1A2-mediated phenacetin O-deethylation, CYP2C8-mediated amodiaquine N-deethylation, CYP2C9-mediated diclofenac 4-hydroxylation, CYP2C19-mediated [S]-mephenytoin 4-hydroxylation, and UGT1A9-mediated propofol glucuronidation with K_i values of 1.2, 4.9, 0.54, 0.57, and 0.3 μM, respectively. Honokiol also moderately inhibited CYP2B6-mediated bupropion hydroxylation and CYP2D6-mediated bufuralol 1'-hydroxylation with K_i values of 17.5 and 12.0 μM, respectively. These in vitro results indicate that honokiol has the potential to cause pharmacokinetic drug interactions with other co-administered drugs metabolized by CYP1A2, CYP2C8, CYP2C9, CYP2C19, and UGT1A9.

Mechanism-based inhibition of recombinant human cytochrome P450 3A4 by tomato juice extract

This study investigates whether tomato juice can inhibit cytochrome P450 (CYP) 3A4-mediated drug metabolism. Three commercially available, additive-free tomato juices, along with homogenized fresh tomato, were analyzed for their ability to inhibit testosterone 6β-hydroxylation activity using human recombinant CYP3A4. Results were compared to that of grapefruit juice. Ethyl acetate extracts of the tomato juices moderately reduced residual activity of CYP3A4 testosterone 6β-hydroxylation activity by 19.3-26.2% with 0-min preincubation. Residual activity was strongly reduced by 69.9-83.5% at 20-min preincubation, a reduction similar to that of grapefruit juice extract, known to contain constituents of mechanism-based inhibitors. One juice extract (tomato juice C) showed irreversible dose- and preincubation time-dependent and partial nicotinamide adenine dinucleotide phosphate (NADPH)-dependent inhibition of CYP3A4 activity. Furthermore, we examined whether the CYP3A4 inhibitory effect of tomato juice was substrate dependent by examining midazolam 1'-hydroxylation activity and nifedipine oxidation activity, in addition to testosterone 6β-hydroxylation activity. Tomato juice showed a potent inhibitory effect on nifedipine oxidation activity, which was comparable to that on testosterone 6β-hydroxylation activity; however, it showed a weak inhibitory effect on midazolam 1'-hydroxylation activity. We conclude that tomato juice contains one or more mechanism-based and competitive inhibitor(s) of CYP3A4. Additionally, significant CYP3A4 inhibitory activity did not result from lycopene, a major compound in tomato. Although the active compound was uncertain, a strong CYP3A4 inhibitory activity was observed in other solanaceous plants, i.e., potato, eggplant, sweet pepper, and capsicum. Therefore, responsible compounds in tomato are likely commonly shared among solanaceous vegetables.

Drug-nutrient interactions: a broad view with implications for practice

The relevance of drug?nutrient interactions in daily practice continues to grow with the widespread use of medication. Interactions can involve a single nutrient, multiple nutrients, food in general, or nutrition status. Mechanistically, drug?nutrient interactions occur because of altered intestinal transport and metabolism, or systemic distribution, metabolism and excretion, as well as additive or antagonistic effects. Optimal patient care includes identifying, evaluating, and managing these interactions. This task can be supported by a systematic approach for categorizing interactions and rating their clinical significance. This review provides such a broad framework using recent examples, as well as some classic drug?nutrient interactions. Pertinent definitions are presented, as is a suggested approach for clinicians. This important and expanding subject will benefit tremendously from further clinician involvement.

Polypharmacy and food-drug interactions among older persons: a review

Polypharmacy is generally defined as the use of 5 or more prescription medications on a regular basis. The average number of prescribed and over-the-counter medications used by community-dwelling older adults per day in the United States is 6 medications, and the number used by institutionalized older persons is 9 medications. Almost all medications affect nutriture, either directly or indirectly, and nutriture affects drug disposition and effect. This review will highlight the issues surrounding polypharmacy, food-drug interactions, and the consequences of these interactions for the older adult.

Corydaline inhibits multiple cytochrome P450 and UDP-glucuronosyltransferase enzyme activities in human liver microsomes

Corydaline is a bioactive alkaloid with various antiacetylcholinesterase, antiallergic, and antinociceptive activities found in the medicinal herb Corydalis Tubers. The inhibitory potential of corydaline on the activities of seven major human cytochrome P450 and four UDP-glucuronosyltransferase enzymes in human liver microsomes was investigated using LC-tandem MS. Corydaline was found to inhibit CYP2C19-catalyzed S-mephenytoin-4’-hydroxylatoin and CYP2C9-catalyzed diclofenac 4-hydroxylation, with K_i values of 1.7 and 7.0 μM, respectively. Corydaline also demonstrated moderate inhibition of UGT1A1-mediated 17β-estradiol 3-glucuronidation and UGT1A9-mediated propofol glucuronidation with K_i values of 57.6 and 37.3 μM, respectively. In the presence of corydaline, CYP3A-mediated midazolam hydroxylation showed a decrease with increasing preincubation time in a dose-dependent manner with K_i values of 30.0 μM. These in vitro results suggest that corydaline should be evaluated for potential pharmacokinetic drug interactions in vivo due to potent inhibition of CYP2C19 and CYP2C9.