Current Drug Metabolism - Volume 23, Issue 2, 2022

Metabiotics have emerged as the safer alternatives to probiotics in last decade. Unlike probiotics that are live microbes, metabiotics are the low molecular weight bioactive metabolites produced by the gut microbiota. While offering a similar profile of health benefits as that of probiotics, metabiotics are free from the risks and uncertain responses associated with administration of live bacteria into the body. Metabiotics have demonstrated substantial effectiveness across the ethnicities, age, gender and nutritional habits in a number of metabolic disorders, including obesity. Obesity is attributed to the offsetting of the energy homeostasis of the body due to a number of genetic, endocrinological, and environmental factors leading to obesity. The obesogenic mechanisms are quite complicated as they result from a complex interplay among a number of factors. Owing to a variety of constituents exerting their action through different pathways, metabiotics offer a pragmatic option for treatment as well as prevention of obesity by addressing heterogeneous aspects of its aetiology. In this review, we categorize various components of metabiotics and discuss their cross-talk with host cells at the molecular level. We also discuss the challenges in understanding these interactions and their potential effects on obesity treatment and prevention strategies. Considering the alarming rise in obesity all over the world, metabiotics offer an attractive non-pharmacological approach to spearhead the strategies being designed to combat the challenges posed by the obesity epidemic.

Background: The absorption, distribution, metabolism, and excretion (ADME) of traditional Chinese medicine (TCM) components are closely related to their therapeutic efficacy, toxic effects, and drug interactions. Based on the study of the whole process of ADME in TCM, it is important to screen out the key pharmacokinetic index components (pharmacokinetics PK/toxicokinetics TK makers), which can be beneficial for their clinical application or drug development. Although the detection of traditional small molecular drug’s in vivo ADME process can be achieved by radioisotope methods, this approach might not be useful for the case of TCM. In detail, it is very difficult to label and trace each component in complex Chinese medicine, while it is also difficult to accurately follow the position of tracer in the whole in vivo process. In short, it is a tough task to obtain the ADME information of Chinese medicine, especially in the case of a clinical study. Methods: We searched several scientific databases, including Pubmed, ACS, ScienceDirect, Springer, Wiley, etc., by using “Chinese medicine” and “in vivo metabolism” as keywords. By summarizing the current reports as well as our recent progress in this field, this review aims to summarize current research methods and strategies for ADME study of TCM based on high-resolution mass spectrometry-based data acquisition and data mining technology which is an important approach but has not been systematically reviewed. Results: With the development of various hybrid tandem high-resolution mass spectrometry (Q-TOF, LTQ FT, Q-Exactive), liquid chromatography-high resolution mass spectrometry (LC-HRMS) has become the mainstream method in studying ADME process of TCM. This review aims to comprehensively summarize current research technologies and strategies based on high-resolution mass spectrometry, with emphasis on the following three aspects: (1) comprehensive and automatic acquisition technologies for the analysis of in vivo TCM components (i.e., BEDDA); (2) quick and comprehensive identification techniques for analyzing in vivo chemical substances and metabolites of TCM (i.e., PATBS or metabolomic analysis); (3) efficient correlation determination between in vivo or in vitro compounds and their metabolic transformation (i.e., MTSF). Conclusion: To the best of our knowledge, this is a pioneering review for systematically summarizing the analysis methods and strategies of ADME in TCM, which can help understand the whole ADME process, therapeutic molecular basis, or toxic substances of TCM. Furthermore, this review can also provide a feasible strategy to screen out PK/TK markers of TCM, while this information can be helpful to elucidate the pharmacodynamics or toxicity mechanisms of Chinese medicines and be useful in their future drug development. At the same time, we also hope that this review can provide ideas for further improvement of TCM analysis methods and help rational clinical use of TCM and the development of new drugs.

Background: Anastrozole (ATZ) is a selective non-steroidal inhibitor widely used for the treatment of breast cancer in post-menopausal women. ATZ exerts its biological activity by inhibiting the enzyme aromatase, which is responsible for converting androgens to estrogens. Piperine (PIP), a natural alkaloid and the main component of black pepper, is used as a bioenhancer and for combating a variety of health issues ranging from upset stomach to dental problems. Introduction: ATZ has been reported to have poor water solubility and less bioavailability. The novel combination of ATZ and PIP was proposed to enhance the bioavailability of both the compounds. However, there are no reported studies on the simultaneous estimation of ATZ and PIP as well as stability studies to explore their potential interactions and degradation profiling. Method: A simple, accurate, precise, robust, sensitive, reliable, and economic analytical method for the simultaneous estimation of ATZ and PIP was developed using acetonitrile and water (60:40) as the mobile phase. Forced degradation studies and characterization of degradants were performed, and degradants were identified for molecular weight using LC-QTOF-ESI-MS; the structures of degradants were confirmed with mass accuracy measurements. The mechanism of each degradant has also been described in more detail in the manuscript. Results and Conclusion: A total of fourteen degradants were characterized and reported for their good human oral absorption. A precise, robust, accurate, cheap, and sensitive RP-HPLC-DAD simultaneous method for the estimation of ATZ and PIP has been developed. From the future point of view, there is huge scope to conduct pharmacological, pharmacodynamic, and drug-herb interaction studies based on this fruitful outcome. All the degradants may be screened against MDR-resistant breast cancer in the future to check their potential as a drug target.

Backgrond: Astragaloside IV (AST) and metoprolol are often used together to treat cardiovascular diseases, while the herb-drug interaction (HDI) between them is still unclear. Objective: This study investigates the effect of AST on the pharmacokinetics of metoprolol in rats and its mechanism to predict the HDI. Method: First, IC50 value of AST on nine CYP450 enzymes in human liver microsomes (HLMs) was determined by the cocktail method. We explored the effect of AST on the pharmacokinetics of metoprolol (metabolized by CYP2D6) in vivo. Twelve male SD rats were equally divided into two groups, with or without pretreatment of AST (3 mg/kg/day) for 7 days, and they received metoprolol (27 mg/kg) by oral administration. Blood samples were determined using HPLC. Finally, the mechanism of AST was explored. Results: AST exhibited a moderate inhibitory effect on CYP2D6 with IC50 value of 32.28 μM. The pharmacokinetic parameters of metoprolol were significantly altered by AST with the increase of AUC0-∞ (538.81 ± 51.41 to 1088.34 ± 86.46 μg*min/mL, P<0.05) and Cmax (6.21 ± 0.56 to 8.34 ± 0.87 μg/ml, P<0.05). The investigation of the mechanism showed AST to be an irreversible inhibitor of CYP2D6 with KI value of 2.9 μM and Kinact of 0.018 min⁻¹, respectively. Conclusion: AST was found to increase the plasma exposure of metoprolol in rats. AST reduced the metabolism of metoprolol by inhibiting CYP2D6 activity. The HDI might enhance when metoprolol and AST will be applied in combination.

Background and Objective: Concurrent usage of proton pump inhibitors and their effect on survival and medication termination has been found in individuals receiving protein kinase inhibitor chemotherapy. To investigate the drug-drug interaction mechanism between CDK inhibitors and proton pump inhibitors, the in-silico docking approach was designed by applying computer simulation modules to predict the binding and inhibitory potential. Methods: The interaction potential of proton pump inhibitors and CDK inhibitors was predicted utilising molecular docking techniques that employed Schrödinger algorithms to capture the dynamics of the CYP450 enzyme-inhibitor interaction between proton pump inhibitors and CDK inhibitors. Additionally, the human liver microsomes assay was used to determine the in vitro half-maximal inhibitory concentration (IC50) of proton pump inhibitors and the inactivation of CDK inhibitors via CYP3A4. Results: Proton pump inhibitors alter the conformation of the CYP3A4 and CYP2C19 enzymes and interact with the heme prosthetic group, as determined by docking studies. It may result in the suppression of CDK inhibitors' metabolism via competitive inhibition at the binding site of an enzyme. Omeprazole and rabeprazole both significantly block midazolam's 1′-hydroxylation by CYP3A4 in vitro, with IC50 values of 9.86μM and 9.71μM, respectively. When omeprazole and rabeprazole are co-incubated in human liver microsomes at a 30μM concentration equivalent to the Cmax of omeprazole and rabeprazole, rabeprazole significantly prolongs the metabolic clearance of palbociclib, whereas omeprazole affects the ribociclib CYP3A4-mediated metabolism. Conclusion: Using dynamic models, we determined that proton pump inhibitors such as rabeprazole and omeprazole indeed have the potential to cause clinically significant drug-drug interactions with CDK inhibitors in the treatment of estrogen receptor (ER) positive and HER2-positive breast cancer. As a result, it is suggested to use caution when prescribing proton pump inhibitors to these individuals.

Background: Xuanfei Baidu granules (XFBD granules) are based on the prescription of Xuanfei Baidu, which showed promise as a first-line treatment against Corona Virus Disease 2019 (COVID-19) in Wuhan, Hubei. On March 2, 2021, XFBD granules were marketed as a novel drug for epidemic diseases. However, there is little information about the pharmacokinetics and tissue distribution of the main constituents in XFBD granules. Methods: A sensitive analytical method was developed for detecting the marker components of XFBD granules by ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOFMS/ MS), and for studying its pharmacokinetics and tissue distribution by UPLC-QDa. Results: Following an oral administration of a single granule in experimental rats at a dose of 14 g/kg for pharmacokinetic and tissue distribution studies, 42 compounds and nine analytes were identified in XFBD granules. Nine compounds were detected in the lungs and the liver of the rats. Six compounds were detected in the kidneys. Five compounds were detected in the spleen and three were detected in the heart. As it went undetected in the brain, XFBD granules are considered unable to cross the blood-brain barrier. Conclusion: A sensitive UPLC-Q-TOF-MS/MS method was established and validated for the quantification of nine components in rat plasma and tissue samples. This method was successfully applied to study the pharmacokinetics and tissue distribution profiles of XFBD granules after their oral administration.

Background: Significant inter-subject variability in pharmacokinetics and clinical outcomes has been observed for the antimalarial agent piperaquine (PQ). PQ is metabolized by CYP3A4, mainly regulated by the pregnane X receptor (PXR). CYP3A4(*1B) polymorphism did not affect PQ clearance. Objectives: The effect of PXR (8055C>T) polymorphism on the pharmacokinetic profiles of PQ was investigated. Methods: The pharmacokinetic profiles of PQ and its major metabolite PQ N-oxide (PQM) were studied in healthy Chinese subjects after recommended oral doses of artemisinin-PQ. Twelve subjects were genotyped using PCRRFLP (six in each group with PXR 8055CC and 8055TT), and plasma concentrations were determined by a validated LC/MS/MS method. The dose-adjusted exposure (AUC and Cmax) to PQ or PQM was investigated, and the metabolic capability of PQ N-oxidation was determined by AUCPQM/AUCPQ. The antimalarial outcome of PQ was evaluated using its day 7 concentration. Results: PQM formation was mediated by CYP3A4/3A5. Interindividual variability in dose-adjusted AUC of PQ and PQM was relatively low (%CV, <30.0%), whereas a larger inter-variability was observed for Cmax values (%CV, 68.1% for PQ). No polymorphic effect was found for PXR (C8055T) on the pharmacokinetic profiles of PQ or its Cday 7 concentrations. Conclusion: Both CYP3A4 and CYP3A5 were involved in PQ clearance. The genotypes of PXR (C8055T) may not contribute to the variability in PQ pharmacokinetics as well as antimalarial outcomes. There might be a low risk of variable exposures to PQ in malaria patients carrying mutated PXR (8055C>T) genes, which deserves further study, especially in a larger sample size.