Current Drug Metabolism - Volume 24, Issue 6, 2023

One of the key factors contributing to mortality and morbidity globally is infectious ailments. According to recent statistics from WHO, amplified antimicrobial resistance occurrence among bacteria signifies the utmost threat to global public health. Bacteria have developed various strategies to resist antimicrobials, including enzymatic inactivation of antibiotics, drug efflux, modifications of the antibiotic molecule or chemical alteration of the antibiotic, limited drug uptake, etc. Furthermore, the inefficiency of antimicrobial drugs against resistant bacteria due to low solubility, instability, and associated side effects augments challenges to combat these resistant pathogens. This has attracted the attention of researchers to create nano-delivery and targeting techniques. This review presents an overview of antimicrobial resistance (AMR), its various subtypes, as well as mechanisms involved in AMR. This review also describes current strategies and applications of various nanocarriers, including nanoparticles, liposomes, lipid-based nanoparticles, micelles, and polymeric nanoparticles.

Background: Chemotherapeutic drugs used in cancer treatment often result in gastrointestinal toxicity, notably diarrhea, impacting patients’ quality of life. Complementary and Alternative Medicine (CAM) has garnered increasing interest as an alternative to conventional approaches as a potential solution for managing chemotherapyinduced diarrhea (CID). Objective: To summarize current research focusing on herbal medicines as adjuvant therapy to prevent or treat chemotherapy-induced diarrhea, including clinical assessments, mechanism of actions, active components, and potential pharmacokinetic interactions between herbal medicines and chemotherapeutic drugs. Methods: We performed the literature review from PubMed, CNKI, Google Scholar, Web of Science, and Scopus using “Chemotherapy”, “Diarrhea,” and “Complementary and Alternative Medicine” as the search keywords. Results: Using herbal medicines as adjuvants provides an effective approach to treating or preventing CID with improved or unaffected antitumor activity of chemotherapeutic drugs. Among these herbal formulations, scutellaria, ginger, and ginseng are the most frequently used herbs in the prescriptions for CID. The main antidiarrheal components in herbs include wogonin, baicalin, chrysin, quercetin, gingerol, and ginsenosides. These herbs, formulations, and bioactive components relieved CID through different mechanisms, including directly decreasing local drug exposure, anti-inflammation, inhibiting epithelial apoptosis, or promoting epithelium stem cell regeneration. The application of herbal medicines as adjunctive therapies showed efficacy in preventing or treating CID in multiple clinical trials. However, more well-designed clinical studies are expected to validate the results further. Despite some clinical studies demonstrating that certain herbal medicines could potentially attenuate CID and improve efficacy, it remains necessary to evaluate herbal safety. The interactions between herbs and drugs are also potential concerns, but few clinical trials have focused on investigating this aspect. Conclusion: In clinical practise, herbal medications show potential as adjuvant treatments for gastrointestinal toxicities induced by chemotherapy, particularly diarrhoea. Further well-designed clinical studies are needed to validate their efficacy, ensure safety, and explore potential drug-herb interactions.

Background: 3-acetyl-11-keto-beta-boswellic acid (AKBA) and 11-keto-boswellic acid (KBA) are the main active components of frankincense as pentacyclic triterpenoids, which are designated by the European Pharmacopoeia 8.0 as the quality standard for the evaluation of Indian frankincense, 2-methoxy-8,12-epoxygermacra- 1(10),7,11-trien-6-one (MCS134) is a non-volatile sesquiterpene compound in myrrh. Objective: In this paper, the absorption pharmacokinetics and metabolites of AKBA, KBA and MCS134 after frankincense, myrrh and their compatibility were analyzed, elaborated their absorption and metabolism mechanism and provided the ideas for the research on the bioactive components of frankincense and myrrh compatibility in vivo. Methods: The area under the blood concentration time curve (AUC), half-life (t1/2) and drug clearance (CL) of AKBA, KBA and MCS134 in rats were analyzed by LC-TQ / MS. The metabolites of AKBA, KBA and MCS134 in rats were analyzed by ultra-high pressure liquid chromatography with a linear ion trap-high resolution Orbitrap mass spectrometry system (UHPLC-LTQ-Orbitrap-MS). Results: The results showed that AKBA, KBA and MCS134 reached the maximum plasma concentration at about 2 h, 2 h and 15 min, respectively. AUC0-tand t1/2of the three components increased in varying degrees after compatibility, and the clearance/ bioavailability (CL/F) decreased. AKBA, KBA and MCS134 were metabolized in phase I and phase II in rats, and there represented differences before and after compatibility. Conclusion: After the compatibility of frankincense and myrrh, the absorption of effective components was improved to some extent, and there were some differences in the metabolites in rats. The results provide ideas for elucidating the in vivoeffect mechanism of frankincense and myrrh.

Background: Catalpol, one of the main bioactive components isolated from Rehmannia glutinosa, was developed by Suzhou Youseen for the treatment of ischemic stroke; however, preclinical information about its absorption, distribution, metabolism, and excretion (ADME) in animals is inadequate. Objective: This study aimed to illuminate the pharmacokinetics (PK), mass balance (MB), tissue distribution (TD), and metabolism of catalpol after a single intragastric administration of 30 mg/kg (300 μCi/kg) [³H]catalpol in rats. Methods: Radioactivity in plasma, urine, feces, bile, and tissues was measured by liquid scintillation counting (LSC), and metabolite profiling was characterized by UHPLC-β-ram and UHPLC-Q-Exactive plus MS. Results: The radio pharmacokinetic results showed that catalpol was rapidly absorbed by Sprague128;’Dawley (SD) rats, with a median Tmaxof 0.75 h and an arithmetic mean half-life (t1/2) of the total radioactivity of approximately 1.52 h in plasma. The mean recovery of the total radioactive dose was 94.82%±1.96% over 168 h postdose (57.52%±12.50% in the urine and 37.30%±12.88% in the feces). The parent drug catalpol was the predominant drugrelated substance in rat plasma and urine, while M1 and M2, two unidentified metabolites, were detected in feces. When [³H]catalpol was incubated with β-glucosidase and rat intestinal flora, we found that the same metabolites M1 and M2 were produced in both incubation systems. Conclusions: Catalpol was excreted mainly through the urine. The drug-related substances were primarily concentrated in the stomach, large intestine, bladder, and kidney. Only the parent drug was detected in the plasma and urine, and M1 and M2 were detected in the feces. We speculate that the metabolism of catalpol in rats was mainly mediated by the intestinal flora, resulting in an aglycone-containing hemiacetal hydroxyl structure.

Background: Palbociclib and ribociclib are substrates of efflux transporter P-glycoprotein which plays a key role in absorption and transport of these drugs. Proton pump inhibitors, when co-administered with them are known to show inhibitory effect on P-glycoprotein. Objective: Therefore, this study aims to investigate the role of proton pump inhibitors in inhibition of P-glycoprotein mediated efflux of palbociclib and ribociclib. Method: A combined approach of molecular docking and ex vivo everted gut sac model was implemented to predict the potential of proton pump inhibitors i.e., omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole to inhibit the P-glycoprotein mediated intestinal transport of palbociclib and ribociclib and study the molecular basis of interaction taking place. Results: Molecular docking studies revealed that omeprazole, rabeprazole and pantoprazole bound to the ATP site of nucleotide binding domain with binding energies of -27.53, -29.56 and -38.44 Kcal/mol respectively. In ex vivo studies, rabeprazole and omeprazole, affected the absorptive permeability of palbociclib by 3.04 and 1.26 and ribociclib by 1.76 and 2.54 folds, respectively. Results of molecular docking studies and ex vivostudies highlighted that proton pump inhibitors bound to the ATP binding site to block its hydrolysis thereby inhibiting the P-glycoprotein mediated efflux of palbociclib and ribociclib. Conclusion: The experimental evidence presented highlights the fact that proton pump inhibitors have potential to inhibit P-glycoprotein, giving rise to drug interactions with palbociclib and ribociclib. Hence, monitoring is required while proton pump inhibitors and cyclin-dependent kinase inhibitors are being co-administered to avoid adverse events.

Aim: The study aimed to identify the key pharmacogenetic variable influencing the therapeutic outcomes of warfarin using machine learning algorithms and bioinformatics tools. Background: Warfarin, a commonly used anticoagulant drug, is influenced by cytochrome P450 (CYP) enzymes, particularly CYP2C9. MLAs have been identified to have great potential in personalized therapy. Objective: The purpose of the study was to evaluate MLAs in predicting the critical outcomes of warfarin therapy and validate the key predictor genotyping variable using bioinformatics tools. Methods: An observational study was conducted on adults receiving warfarin. Allele discrimination method was used for estimating the single nucleotide polymorphisms (SNPs) in CYP2C9, VKORC1, and CYP4F2. MLAs were used for identifying the significant genetic and clinical variables in predicting the poor anticoagulation status (ACS) and stable warfarin dose. Advanced computational methods (SNPs' deleteriousness and impact on protein destabilization, molecular dockings, and 200 ns molecular dynamics simulations) were employed for examining the influence of CYP2C9SNPs on structure and function. Results: Machine learning algorithms revealed CYP2C9to be the most important predictor for both outcomes compared to the classical methods. Computational validation confirmed the altered structural activity, stability, and impaired functions of protein products of CYP2C9SNPs. Molecular docking and dynamics simulations revealed significant conformational changes with mutations R144C and I359L in CYP2C9. Conclusion: We evaluated various MLAs in predicting the critical outcome measures associated with warfarin and observed CYP2C9as the most critical predictor variable. The results of our study provide insight into the molecular basis of warfarin and the CYP2C9gene. A prospective study validating the MLAs is urgently needed.

The authors declare that after the publication of the article, it was noticed that two citations were inadvertently omitted. The references have now been included as [74b] and [74c]: [74] (b) Vitiello, M.; Galdiero, M.; Galdiero, M. Inhibition of Viral-Induced Membrane Fusion by Peptides. Protein Pep. Lett., 2009, 16(7), 786-793. (c) Galdiero, S.; Falanga, A.; Vitiello, M.; D'Isanto, M.; Cantisani, M.; Kampanaraki, A.; Benedetti, E.; Browne, H.; Galdiero, M. Peptides containing membrane-interacting motifs inhibit herpes simplex virus type 1 infectivity. Peptides, 2008, 29(9), 1461- 1471. The authors would like to include this reference in the online version of the article to ensure completeness.