Active Metabolite Research Articles

Formulation of Saxagliptin Oral Films: Optimization, Physicochemical Characterization, In-Vivo Assessment, and In-Vitro Real-Time Release Monitoring via a Novel Polyaniline Nanoparticles-Based Solid-Contact Screen Printed Ion-Selective Electrode

Oral dispersible films have received broad interest due to fast drug absorption and no first-path metabolism, leading to high bioavailability and better patient compliance. Saxagliptin (SXG) is an antidiabetic drug that undergoes first-path metabolism, resulting in a less active metabolite, so the development of SXG oral dispersible films (SXG-ODFs) improves SXG bioavailability. The formula optimisation included a response surface experimental design and the impact of three formulation factors, the type and concentration of polymer and plasticiser concentration on in-vitro disintegration time and folding endurance. Two optimised SXG-ODFs prepared using either polyvinyl alcohol (PVA) or hydroxypropyl methylcellulose were investigated. SXG-ODFs prepared with PVA demonstrated a superior rapid disintegration time, ranging from 17 to 890 s, with the fastest disintegration time recorded at 17 s. These short durations can be attributed to the hydrophilic nature of PVA, facilitating rapid hydration and disintegration upon contact with saliva. Additionally, PVA-based films displayed remarkable folding endurance, surpassing 200 folds without rupture, indicating flexibility and stability. The high tensile strength of PVA-based films further underscores their robust mechanical properties, with tensile strength values reaching up to 4.53 MPa. SXG exhibits a UV absorption wavelength of around 212 nm, posing challenges for traditional quantitative spectrophotometric analysis, so a polyaniline nanoparticles-based solid-contact screen-printed ion-selective electrode (SP-ISE) was employed for the determination of SXG release profile effectively in comparison to HPLC. SP-ISE showed a better real-time release profile of SXG-ODFs, and the optimised formula showed lower blood glucose levels than commercial tablets.Graphical

A single-dose, randomized, open-label, four-period, crossover equivalence trial comparing the clinical similarity of the proposed biosimilar rupatadine fumarate to reference Wystamm® in healthy Chinese subjects

PurposeThe aim of this study was to evaluate the bioequivalence of two formulations of rupatadine (10-mg tablets) under fasting and fed conditions in healthy Chinese subjects.MethodsA total of 72 subjects were randomly assigned to the fasting cohort (n = 36) and fed cohort (n = 36). Each cohort includes four single-dose observation periods and 7-day washout intervals. Blood samples were collected at several timepoints for up to 72 h post-dose. The plasma concentration of rupatadine and the major active metabolites (desloratadine and 3-hydroxydesloratadine) were analyzed by a validated HPLC–MS/MS method. The non-compartmental analysis method was employed to determine the pharmacokinetic parameters. Based on the within-subject standard deviation of the reference formulation, a reference-scaled average bioequivalence or average bioequivalence method was used to evaluate the bioequivalence of the two formulations.ResultsFor the fasting status, the reference-scaled average bioequivalence method was used to evaluate the bioequivalence of the maximum observed rupatadine concentration (Cmax; subject standard deviation > 0.294), while the average bioequivalence method was used to evaluate the bioequivalence of the area under the rupatadine concentration–time curve from time 0 to the last detectable concentration (AUC0-t) and from time 0 to infinity (AUC0-∞). The geometric mean ratio (GMR) of the test/reference for Cmax was 95.91%, and the upper bound of the 95% confidence interval was 95.91%. For AUC0-t and AUC0-∞ comparisons, the GMR and 90% confidence interval (CI) were 98.76% (93.88%–103.90%) and 98.71% (93.93%–103.75%), respectively. For the fed status, the subject standard deviation values of Cmax, AUC0-t, and AUC0-∞ were all <0.294; therefore, the average bioequivalence method was used. The GMR and 90% CI for Cmax, AUC0-t, and AUC0-∞ were 101.19% (91.64%–111.74%), 98.80% (94.47%–103.33%), and 98.63% (94.42%–103.03%), respectively. The two-sided 90% CI of the GMR for primary pharmacokinetic endpoints of desloratadine and 3-hydroxydesloratadine was also within 80%–125% for each cohort. These results met the bioequivalence criteria for highly variable drugs. All adverse events (AEs) were mild and transient.ConclusionThe test drug rupatadine fumarate showed a similar safety profile to the reference drug Wystamm® (J. Uriach y Compañía, S.A., Spain), and its pharmacokinetic bioequivalence was confirmed in healthy Chinese subjects based on fasting and postprandial status.Clinical trial registration:http://www.chinadrugtrials.org.cn/index.html, identifier CTR20213217

Preliminary Purification and Partial Characterization of a Functional Bacteriocin of Lacticaseibacillus paracasei Zhang and Mining for its Gene Cluster.

Bacteriocins produced by lactic acid bacteria (LAB) have good potential for use as food biopreservatives. Lacticaseibacillus paracasei Zhang (L. paracasei Zhang) is both a food use and a probiotic bacterium. This study aimed to purify and preliminary characterize the active antibacterial metabolite of L. paracasei Zhang. The cell-free supernatant of L. paracasei Zhang was collected and purified by ultrafiltration and gel filtration chromatography. The 1-3kDa active fraction could inhibit the growth of Staphylococcus aureus but not Escherichia coli. Further antibacterial activity assays revealed its capacity to suppress various foodborne and human opportunistic pathogens (including Staphylococcus aureus, Pseudomonas fluorescens, Pseudomonas aeruginosa, Listeria monocytogenes, and Bacillus cereus), but not fungi. The antibacterial activity showed good tolerance to heat (40 to 100°C), acid-base (pH 2-3 and pH 6-10), and digestions by a number of industrial and animal/human enzymes (such as trypsin, pepsin, α-amylase, and protease K, except papain); these desired properties make it a suitable biopreservative to be used in harsh and complex industrial production processes. The high papain sensitivity suggested a proteinaceous/peptide nature of the bioactivity. Moreover, our genomic data mining for bacteriocin through BAGEL4 revealed an area of interest encoding a complete set of putative genes required for bacteriocin production. In conclusion, our study showed that L. paracasei Zhang can produce extracellular functional antibacterial metabolite, likely a class II bacteriocin. Our preliminary extraction and characterization of the active metabolite demonstrated that it has good potential to be used as a biopreservative or an agent for suppressing gastrointestinal infections.

Cholesterol Oxime Olesoxime Assessed as a Potential Ligand of Human Cholinesterases

Olesoxime, a cholesterol derivative with an oxime group, possesses the ability to cross the blood–brain barrier, and has demonstrated excellent safety and tolerability properties in clinical research. These characteristics indicate it may serve as a centrally active ligand of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), whose disruption of activity with organophosphate compounds (OP) leads to uncontrolled excitation and potentially life-threatening symptoms. To evaluate olesoxime as a binding ligand and reactivator of human AChE and BChE, we conducted in vitro kinetic studies with the active metabolite of insecticide parathion, paraoxon, and the warfare nerve agents sarin, cyclosarin, tabun, and VX. Our results showed that both enzymes possessed a binding affinity for olesoxime in the mid-micromolar range, higher than the antidotes in use (i.e., 2-PAM, HI-6, etc.). While olesoxime showed a weak ability to reactivate AChE, cyclosarin-inhibited BChE was reactivated with an overall reactivation rate constant comparable to that of standard oxime HI-6. Moreover, in combination with the oxime 2-PAM, the reactivation maximum increased by 10–30% for cyclosarin- and sarin-inhibited BChE. Molecular modeling revealed productive interactions between olesoxime and BChE, highlighting olesoxime as a potentially BChE-targeted therapy. Moreover, it might be added to OP poisoning treatment to increase the efficacy of BChE reactivation, and its cholesterol scaffold could provide a basis for the development of novel oxime antidotes.

Evaluating Drug Interactions between Ritonavir and Opioid Analgesics: Implications from Physiologically Based Pharmacokinetic Simulation

Several commonly used opioid analgesics, such as fentanyl, sufentanil, alfentanil, and hydrocodone, are by report primarily metabolized by the CYP3A4 enzyme. The concurrent use of ritonavir, a potent CYP3A4 inhibitor, can lead to significant drug interactions. Using physiologically based pharmacokinetic (PBPK) modeling and simulation, this study examines the effects of different dosing regimens of ritonavir on the pharmacokinetics of these opioids. The findings reveal that co-administration of ritonavir significantly increases the exposure of fentanyl analogs, with over a 10-fold increase in the exposure of alfentanil and sufentanil when given with ritonavir. Conversely, the effect of ritonavir on fentanyl exposure is modest, likely due to additional metabolism pathways. Additionally, the study demonstrates that the steady-state exposure of hydrocodone and its active metabolite hydromorphone can be increased by up to 87% and 95%, respectively, with concurrent use of ritonavir. The extended-release formulation of hydrocodone is particularly affected. These insights from PBPK modeling provide valuable guidance for optimizing opioid dosing and minimizing the risk of toxicity when used in combination with ritonavir-containing prescriptions.

Study the hepatoprotective effect of the methanolic extract of Plumbago auriculata Lam. against CCl4-induced hepatocyte damage in mice

The liver is an important organ in the body; its diseases are considered the major causes of morbidity and mortality around the world. Hepatotoxic chemicals cause damage to liver cells. Medicinal plants have a powerful hepatoprotective effect. This study has been aimed to assess the potential hepatoprotective effect of the methanolic extract of Plumbago auriculata Lam. against carbon tetrachloride (CCl4)- induced hepatocyte damage in albino mice. The methanolic extract of the plant was subjected to preliminary phytochemical analysis to determine the presence of secondary metabolites according to standard protocols. The acute toxicity study was carried out to measure the LD50. Swiss albino mice were divided into 4 groups treated intraperitoneally (IP) once daily for 7 days; the first group was a negative control, while the second group, considered as a CCl4 model, received a single dose of carbon tetrachloride during the last day. The third group received 500 mg/kg of body weight of methanolic extract of P. auriculata, and the last group received 100 mg/kg of body weight of standard silymarin, after 2 h of treatment, on the last day, all animals (except negative control group) have received CCl4 at a dose of 1 mL/kg of body weight. Biochemical analysis of collected blood and histopathological examination were performed. Results revealed that the preliminary phytochemical screening of the methanolic extract of the plant confirmed the presence of many biologically active secondary metabolites like flavonoids, steroids, terpenoids, saponins, glycosides and phenols and LD50 of the extract was 2.5 g/kg. The CCl4- intoxicated mice showed an increase in biochemical enzyme levels (ALT and AST) compared with the negative control group. The extract of 500 mg/kg revealed a significant reduction (p ? 0.05) in enzyme activities. The histopathological analysis of plant extract and silymarin-treated groups revealed a decrease in the pathological features compared with the CCl4-intoxicated group. It was concluded that the extract of P. auriculata has a significant effect on hepatoprotection against CCl4-induced hepatocyte damage and this may be because of the combined effects of the bioactive compositions of plant extract.

Chamaecyparis lawsoniana and Its Active Compound Quercetin as Ca2+ Inhibitors in the Contraction of Airway Smooth Muscle

The Cupressaceae family includes species considered to be medicinal. Their essential oil is used for headaches, colds, cough, and bronchitis. Cedar trees like Chamaecyparis lawsoniana (C. lawsoniana) are commonly found in urban areas. We investigated whether C. lawsoniana exerts some of its effects by modifying airway smooth muscle (ASM) contractility. The leaves of C. lawsoniana (363 g) were pulverized mechanically, and extracts were obtained by successive maceration 1:10 (w:w) with methanol/CHCl3. Guinea pig tracheal rings were contracted with KCl, tetraethylammonium (TEA), histamine (HIS), or carbachol (Cch) in organ baths. In the Cch experiments, tissues were pre-incubated with D-600, an antagonist of L-type voltage-dependent Ca2+ channels (L-VDCC) before the addition of C. lawsoniana. Interestingly, at different concentrations, C. lawsoniana diminished the tracheal contractions induced by KCl, TEA, HIS, and Cch. In ASM cells, C. lawsoniana significantly diminished L-type Ca2+ currents. ASM cells stimulated with Cch produced a transient Ca2+ peak followed by a sustained plateau maintained by L-VDCC and store-operated Ca2+ channels (SOCC). C. lawsoniana almost abolished this last response. These results show that C. lawsoniana, and its active metabolite quercetin, relax the ASM by inhibiting the L-VDCC and SOCC; further studies must be performed to obtain the complete set of metabolites of the extract and study at length their pharmacological properties.

Pharmacokinetic/Pharmacodynamic assessment of the structural refinement of clopidogrel focusing on the balance between bioactivation and deactivation.

The delicate balance between ischemic and bleeding risks is a significant consideration in the administration of antiplatelet therapy. Clopidogrel and prasugrel, both members of the thienopyridine class of antiplatelet drugs, are well established for their variability in individual responsiveness and for a high number of bleeding events, respectively. The current study focuses on evaluating the pharmacokinetics and pharmacodynamics of a series of deuterated clopidogrel derivatives, leveraging insights gained from the structure-pharmacokinetic relationships in the development of thienopyridine drugs. Our approaches were based on the molecular skeleton of clopidogrel and adopted the C2-pharmacophore design from prasugrel. The selected C2-pharmacophore distinguishes itself from the acetyloxy substituent of prasugrel by exhibiting a moderated hydrolysis rate, resulting in a gentler formation of the active metabolite. An excessive and burst release of the active metabolite are therefore to be avoided, as it is believed to be associated with an increased risk of bleeding. Our proposed structural modification maintains the hydrolysis-sensitive methyl ester of clopidogrel but replaces it with a deuterated methyl group, which has been shown to effectively reduce metabolic deactivation. The evaluation of the clopidogrel derivatives has been primarily based on the criteria related to the exposure to active metabolites. Three promising compounds demonstrate higher biotransformation efficiency, similar Cmax, delayed Tmax, enhanced antiplatelet activity, and a lower risk of bleeding compared to clopidogrel, when administered at a dosage resulting in a similar exposure to the active metabolites. Significance Statement The pharmacokinetics and pharmacodynamics of a series of newly designed clopidogrel derivatives were assessed to validate the rationale for their structural modifications. Three promising compounds displayed balanced pharmacokinetics, characterized by slower deactivation compared to clopidogrel and a more gradual bioactivation than prasugrel. Under similar exposure to active metabolites, these compounds have demonstrated enhanced antiplatelet activity and a diminished risk of bleeding compared to clopidogrel. The D3-clopidogrel-ozagrel conjugate was found to exert a synergistic therapeutic effect.

The Impact of a 6-Week Nordic Walking Training Cycle and a 14-Hour Intermittent Fasting on Disease Activity Markers and Serum Levels of Wnt Pathway-Associated Proteins in Patients with Multiple Myeloma

Background: Multiple myeloma (MM) accounts for about 10–15% of all diagnosed hematologic malignancies and about 1–2% of all cancer cases. Approximately 80–90% of MM patients develop bone disease and the changes rarely regress. It is only possible to stop or slow their progression. A major role in bone destruction in MM is attributed to the Wnt signaling pathway, and its action can be modified by various types of interventions including training and diet. Therefore, the aim of this project was to evaluate the effects of a Nordic Walking (NW) training cycle and intermittent fasting (IF) on the levels of selected bone turnover markers associated with the Wnt pathway in patients with MM. Materials and methods: Results from 35 patients divided into training (NW and IF NW) and non-training (IF and control) groups were included in the analysis. A 6-week training cycle involving 60 min workouts 3 times a week was conducted. Body mass and composition as well as the levels of vitamin D, calcium and phosphorus, beta2-microglobulin, and albumin were examined before and after the completion of the training cycle. Markers of bone turnover were also determined: sclerostin (SOST), Dickkopf-related protein 1 (DKK-1), osteoprotegrin (OPG), osteopontin (OPN), and Tartrate-resistant acid phosphatase 5b (TRACP 5b). Results: There was no negative effect of IF or combined training and fasting on the nutritional status of the patients (the level of albumins was unchanged). Both training groups showed an increase in serum concentrations of the active metabolite of vitamin D (IF NW and NW: p = 0.001 and p = 0.022, respectively). The change in the concentration of this vitamin negatively correlated with the concentration of TRACP 5b (r = −0.413, p = 0.014). Evaluating the concentrations of markers related to bone turnover, a reduction in the concentrations of SOST (time: p = 0.026, time vs. group: p = 0.033) and TRACP 5b (time: p < 0.001, time vs. group p < 0.001) was indicated. Conclusions: The obtained results allow one to indicate the training with the poles as a safe and beneficial form of physical activity that should be recommended to patients suffering from MM. However, the results obtained in the present study are not sufficient to show the beneficial effect of IF applied without trainings.

Molecularly Imprinted Polymer Biosensor Based on Nitrogen-Doped Electrochemically Exfoliated Graphene/Ti3 CNTX MXene Nanocomposite for Metabolites Detection.

Rapid and accurate quantification of metabolites in different bodily fluids is crucial for a precise health evaluation. However, conventional metabolite sensing methods, confined to centralized laboratory settings, suffer from time-consuming processes, complex procedures, and costly instrumentation. Introducing the MXene/nitrogen-doped electrochemically exfoliated graphene (MXene@N-EEG) nanocomposite as a novel biosensing platform in this work addresses the challenges associated with conventional methods, leveraging the concept of molecularly imprinted polymers (MIP) enables the highly sensitive, specific, and reliable detection of metabolites. To validate our biosensing technology, we utilize agmatine as a significant biologically active metabolite. The MIP biosensor incorporates electrodeposited Prussian blue nanoparticles as a redox probe, facilitating the direct electrical signaling of agmatine binding in the polymeric matrix. The MXene@N-EEG nanocomposite, with excellent metal conductivity and a large electroactive specific surface area, effectively stabilizes the electrodeposited Prussian blue nanoparticles. Furthermore, increasing the content of agmatine-imprinted cavities on the electrode enhances the sensitivity of the MIP biosensor. Evaluation of the designed MIP biosensor in buffer solution and plasma samples reveals a wide linear concentration range of 1.0 nM-100.0 μM (R2 = 0.9934) and a detection limit of 0.1 nM. Notably, the developed microfluidic biosensor offers low cost, rapid response time to the target molecule (10 min of sample incubation), good recovery results for detecting agmatine in plasma samples, and acceptable autonomous performance for on-chip detection. Moreover, its high reliability and sensitivity position this MIP-based biosensor as a promising candidate for miniaturized microfluidic devices with the potential for scalable production for point-of-care applications.

The use of deep eutectic solvent-liquid phase microextraction as green analytical sample treatment for the analysis of drugs in urine

In this paper, a natural deep eutectic solvent (NADES)-based liquid phase microextraction (LPME) of 20 pharmaceuticals from urine, employing liquid chromatography tandem mass spectrometry (LC-MS/MS) for precise quantification, has been developed. The chromatographic gradient was accurately evaluated to ensure the effective separation of tramadol, an opioid receptor agonist, and o-desmethylvenlafaxine, one active metabolite of the antidepressant venlafaxine, both compounds sharing identical molecular mass for the precursor ion (Q1: 264.2 m/z) and fragmentation patterns (Quantifier ion: 58.2 m/z; qualifier ion: 246.0 m/z). NADES consisted of menthol-octanoic acid in a molar ratio of 1:2. Using the appropriate extraction conditions, the developed methodology provided appropriate LOQ values, ranging from 15 to 208 ng L–1, with reasonable RSD values (below 11 %), recoveries ranging from 64 to 120 % and preconcentration factors up to 66.6 folds. Application of the developed method to the analysis of urine samples served to highlight its usefulness. An AGREEprep score of 0.64 was obtained despite the demand for substantial sample volumes and the use of LC-MS/MS for analyte determination.

Structure-activity relationships and pharmacokinetic evaluation of L-cystine diamides as L-cystine crystallization inhibitors for cystinuria

AbstractCystinuria is a rare genetic disorder characterized by defective l-cystine reabsorption from the renal proximal tubule, resulting in abnormally high concentrations of L-cystine and subsequent l-cystine crystallization and stone formation in urine. l-Cystine diamides have shown great promise as inhibitors of l-cystine crystallization. The free α-amino groups in l-cystine diamides have previously been shown to be necessary for l-cystine crystallization inhibitory activity. In this study, three additional series of l-cystine diamide analogs were designed to explore further the structure-activity relationships for l-cystine crystallization inhibition. It has been demonstrated that the middle disulfide bond is required for optimal l-cystine crystallization inhibitory activity, and the only regions that can be modified are the two terminal amides. The presence of another basic amine 2–3 atoms away from the amide nitrogen is also critical for optimal activity. Disulfide exchange was found to be the main metabolic pathway resulting in the formation of two molecules of the active mixed disulfide metabolite from a single l-cystine diamide. l-Cystine diamides have the potential to be developed into a much-needed therapy for cystinuria.

Extremophiles and their expanding biotechnological applications.

Microbial life is not restricted to any particular setting. Over the past several decades, it has been evident that microbial populations can exist in a wide range of environments, including those with extremes in temperature, pressure, salinity, and pH. Bacteria and Archaea are the two most reported types of microbes that can sustain in extreme environments, such as hot springs, ice caves, acid drainage, and salt marshes. Some can even grow in toxic waste, organic solvents, and heavy metals. These microbes are called extremophiles. There exist certain microorganisms that are found capable of thriving in two or more extreme physiological conditions simultaneously, and are regarded as polyextremophiles. Extremophiles possess several physiological and molecular adaptations including production of extremolytes, ice nucleating proteins, pigments, extremozymes and exopolysaccharides. These metabolites are used in many biotechnological industries for making biofuels, developing new medicines, food additives, cryoprotective agents etc. Further, the study of extremophiles holds great significance in astrobiology. The current review summarizes the diversity of microorganisms inhabiting challenging environments and the biotechnological and therapeutic applications of the active metabolites obtained as a response to stress conditions. Bioprospection of extremophiles provides a progressive direction with significant enhancement in economy. Moreover, the introduction to omics approach including whole genome sequencing, single cell genomics, proteomics, metagenomics etc., has made it possible to find many unique microbial communities that could be otherwise difficult to cultivate using traditional methods. These findings might be capable enough to state that discovery of extremophiles can bring evolution to biotechnology.

Human bronchopulmonary disposition and plasma pharmacokinetics of oral bemnifosbuvir (AT-527), an experimental guanosine nucleotide prodrug for COVID-19.

Bemnifosbuvir (AT-527) is a novel oral guanosine nucleotide antiviral drug for the treatment of persons with COVID-19. Direct assessment of drug disposition in the lungs, via bronchoalveolar lavage, is necessary to ensure antiviral drug levels at the primary site of SARS-CoV-2 infection are achieved. This Phase 1 study in healthy subjects aimed to assess the bronchopulmonary pharmacokinetics, safety and tolerability of repeated doses of bemnifosbuvir. A total of 24 subjects were assigned to receive bemnifosbuvir twice daily at doses of 275, 550 or 825 mg for up to 3.5 days. AT-511, the free base of bemnifosbuvir, was largely eliminated from the plasma within 6 h post dose in all dosing groups. Antiviral drug levels of bemnifosbuvir were consistently achieved in the lungs with bemnifosbuvir 550 mg twice daily. The mean level of the guanosine nucleoside metabolite AT-273, the surrogate of the active triphosphate metabolite of the drug, measured in the epithelial lining fluid of the lungs was 0.62 µM at 4-5 h post dose. This exceeded the target in vitro 90% effective concentration (EC90) of 0.5 µM for antiviral drug exposure against SARS-CoV-2 replication in human airway epithelial cells. Bemnifosbuvir was well tolerated across all doses tested, and most treatment-emergent adverse events reported were mild in severity and resolved. The favourable pharmacokinetics and safety profile of bemnifosbuvir demonstrates its potential as an oral antiviral treatment for COVID-19, with 550 mg bemnifosbuvir twice daily currently under further clinical evaluation in persons with COVID-19.

Simultaneous determination of unecritinib (TQ-B3101) and its active metabolite crizotinib in rat plasma by LC-MS/MS：An application to pharmacokinetic studies

Unecritinib (TQ-B3101) is a selective tyrosine kinase receptor inhibitor. In the study, in vitro metabolic experiments revealed that the hydrolysis of TQ-B3101 was mainly catalyzed by carboxylesterase 2 (CES2), followed by CES1. Next, a sensitive and reliable LC-MS/MS method was established for the simultaneous determination of TQ-B3101 and its metabolite crizotinib in rat plasma. To prevent in vitro hydrolysis of TQ-B3101, sodium fluoride, the CESs inhibitor at a concentration of 2 M, was immediately added after whole blood collection. Plasma samples were extracted by acetonitrile-induced protein precipitation method, and chromatographically separated on a Gemini C18 column (50 mm × 2.0 mm i.d., 5 μm) using gradient elution with a mobile phase of 0.1% formic acid and 5 mmol/L ammonium acetate with 0.1% formic acid. The retention times for TQ-B3101 and crizotinib were 2.61 and 2.38 min, respectively. The analytes were detected with tandem mass spectrometer by positive electrospray ionization, using the ion transitions at m/z 492.3 → 302.3 for TQ-B3101, m/z 450.3 → 260.3 for crizotinib, and m/z 494.0 → 394.3 for imatinib (internal standard). Method validation was conducted in the linear range of 1.00–800 ng/mL for the two analytes. The precision, accuracy and stabilities all met the acceptance criteria. The pharmacokinetic study indicated that TQ-B3101 was rapidly hydrolyzed to crizotinib with the elimination half-life of 1.11 h after a single gavage administration of 27 mg/kg to Sprague-Dawley rats, and the plasma exposure of TQ-B3101 was only 2.98% of that of crizotinib.

Marine seaweed endophytic fungi-derived active metabolites promote reactive oxygen species-induced cell cycle arrest and apoptosis in human breast cancer cells.

Endophytic fungi have an abundant sources rich source of rich bioactive molecules with pivotal pharmacological properties. Several studies have found that endophytic fungi-derived bioactive secondary metabolites have antiproliferative, anti-oxidant, and anti-inflammatory properties, but the molecular mechanism by which they induce cell cycle arrest and apoptosis pathways is unknown. This study aimed to determine the molecular mechanism underlying the anticancer property of the endophytic fungi derived active secondary metabolites on human breast cancer cells. In this study, we identified four endophytic fungi from marine seaweeds and partially screened its phytochemical properties by Chromatography-Mass Spectrometry (GC-MS) analysis. Moreover, the molecular mechanism underlying the anticancer property of these active secondary metabolites (FA, FB, FC and FE) on human breast cancer cells were examined on MCF-7 cells by TT assay, Apoptotic assay by Acridine orang/Ethidium Bromide (Dual Staining), DNA Fragmentation by DAPI Staining, reactive oxygen species (ROS) determination by DCFH-DA assay, Cell cycle analysis was conducted Flow cytometry and the apoptotic signalling pathway was evaluated by westernblot analysis. Doxorubicin was used as a positive control drug for this experiment. The GC-MS analysis of ethyl acetate extract of endophytic fungi from the marine macro-algae revealed the different functional groups and bioactive secondary metabolites. From the library, we observed the FC (76%), FB (75%), FA (73%) and FE (71%) have high level of antioxidant activity which was assessed by DPPH scavenging assay. Further, we evaluated the cytotoxic potentials of these secondary metabolites on human breast cancer MCF-7 cells for 24h and the IC50 value were calculated (FA:28.62 ± 0.3µg/ml, FB:49.81 ± 2.5µg/ml, FC:139.42 ± µg/ml and FE:22.47 ± 0.5µg/ul) along with positive control Doxorubicin 15.64 ± 0.8µg/ml respectively by MTT assay. The molecular mechanism by which the four active compound induced apoptosis via reactive oxygen species (ROS) and cell cycle arrest in MCF-7 cells was determined H2DCFDA staining, DAPI staining, Acridine orange and ethidium bromide (AO/EtBr) dual staining, flowcytometry analysis with PI staining and apoptotic key regulatory proteins expression levels measured by westernblot analysis. Our findings, revealed the anticancer potential of endophytic fungi from marine seaweed as a valuable source of bioactive compounds with anticancer properties and underscore the significance of exploring marine-derived endophytic fungi as a promising avenue for the development of novel anticancer agents. Further investigations are necessary to isolate and characterize specific bioactive compounds responsible for these effects and to validate their therapeutic potential in preclinical and clinical settings.

Abstract PO5-11-08: Assessing practice patterns of antidepressant medication and tamoxifen use among patients with hormone receptor-positive breast cancer

Abstract Background: Treatment with endocrine therapy such as tamoxifen has been identified as one of the most important variables linked with survival among women with hormone receptor-positive breast cancer (BC). There is significant risk reduction of BC recurrence and BC mortality at 15 years among patients treated with tamoxifen for 5 years compared to no endocrine therapy. Tamoxifen is metabolized in the liver via multiple cytochrome P (CYP) isoforms. To ensure optimal efficacy of tamoxifen, consideration must be given to concomitant use of other commonly prescribed drugs such as antidepressants. Some selective serotonin reuptake inhibitors (SSRIs) are potent inhibitors of CYP2D6, an enzyme that metabolizes tamoxifen into its active metabolite, endoxifen, which has anti-tumor effect. Such inhibition can reduce the plasma concentration of endoxifen which could lead to higher rates of BC recurrence. This resulted in an FDA black box warning discouraging concurrent prescriptions of tamoxifen and SSRIs, yet clinical data to support this warning is lacking. Our aim is to describe the practice patterns of concomitant use of tamoxifen and antidepressant medication at our institution. Methods: This is a single institution retrospective study that included adult women, ages 18-99, with stage I-IV BC, who received adjuvant tamoxifen and were taking an antidepressant medication between years 2016-2021. Patients were identified from a tumor registry database. Patient demographics and tumor characteristics were collected via electronic medical record. Results: A total of 419 patients met the inclusion criteria. At the start of tamoxifen therapy, 348 women were on at least one antidepressant, mostly for Major Depressive Disorder (86%). Of those women, 22% were prescribed a strong/moderately potent CYP inhibitor (paroxetine, fluoxetine, duloxetine, or bupropion) and 43% were prescribed weak or non-CYP inhibiting SSRIs (citalopram, escitalopram, fluvoxamine, and sertraline). The most commonly prescribed antidepressants at the start of tamoxifen, alone or in combination with a second antidepressant, were: venlafaxine (30%), escitalopram (17%), sertraline (13%), citalopram (12%) and duloxetine (10%). Main prescribers of antidepressants were primary care physicians (70%), psychiatrists (10%) followed by academic medical oncologists (7%) and regional medical oncologists (6%). Interestingly, the majority of women continued taking the same antidepressant after starting tamoxifen (76%) while, at least 10% of patients changed anti-depressant classes prior to starting tamoxifen, due to concern for drug-drug interaction. When a different class of antidepressant was chosen after starting tamoxifen (22%), serotonin and norepinephrine reuptake inhibitors (SNRIs) were the most frequent class (48%), followed by a different SSRI (42%). The time in which the antidepressant change occurred was variable, but most commonly prior to initiating tamoxifen. Conclusion: Concurrent use of tamoxifen and antidepressant medications is common. Theoretical risk of reduced efficacy of tamoxifen with inhibitors of CYP leads to medication changes for some but not all patients requiring tamoxifen and an antidepressant medication. This can have clinical implications as stability on a specific antidepressant is important for patients and adjustment may impact control of their mood disorder. In some cases, even if a drug-drug interaction was identified, some patients chose to continue their current antidepressant due to concerns of mood de-stabilization, and in other cases, aromatase inhibitors were started as an alternative. These findings highlight differences in practice patterns for which additional guidance may be helpful in bringing awareness and standardization to care. Citation Format: Mariah Ondeck, Bennett Osantowski, Nerea Lopetegui-Lia, Wei Wei, Alexandra Murray, Amanda Maggiotto, Halle Moore, Erin Roesch. Assessing practice patterns of antidepressant medication and tamoxifen use among patients with hormone receptor-positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-11-08.

Abstract PO3-18-05: Pharmacokinetics (PK) of lasofoxifene (LAS) monotherapy and combined with abemaciclib (Abema)

Abstract Introduction: LAS is a selective estrogen receptor modulator (SERM)/tissue-selective estrogen agonist/antagonist studied in women with osteoporosis and vulvar-vaginal atrophy, and most recently, metastatic breast cancer (mBC) with ESR1 mutations. LAS data in healthy postmenopausal women and young men show linear PK and no differences by age or race (Gardner. J Clin Pharmacol 2006;46:52-58; Prakash. Drug Metab Dispos 2008;26:1218-26; Data on file). Also, no PK differences were found between Caucasian and Japanese patients (Jhee. AACR-JCA 2022, abstract A83; Fountaine. J Clin Pharmacol 2006;46:693-99). Here we report select PK data of LAS (5 mg/day) from women with mBC in the ELAINE 1 and ELAINE 2 oncology trials to indirectly investigate possible drug-drug interactions between LAS and Abema. Methods: Patients with mBC and ESR1 mutations who progressed on endocrine therapy and CDK4/6 inhibitors received LAS 5 mg/day as monotherapy (ELAINE 1) or combined with Abema (provided by Eli Lilly and Co) 150 mg BID (ELAINE 2). Blood was collected prior to daily dosing at weeks 2, 4, 8, and every 4 weeks up to the final visit in ELAINE 1, and visits during the first 8 weeks in ELAINE 2, to determine the plasma trough steady-state concentrations (Css) of LAS, Abema, and two active Abema metabolites (M2 and M20). LAS was assayed using validated high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS; detection 0.025 to 25.0 ng/mL); levels below the lower limit of quantification (LLOQ) were reported as 0 ng/mL. Abema and its M2 and M20 metabolites were measured by validated Turbo Ion Spray LC/MS/MS (detection 1.00 to 500 ng/mL); values below the LLOQ were reported as < LLOQ ng/mL. Mean trough Css at each visit were calculated for LAS (ELAINE 1 and 2), and Abema and its M2 and M20 metabolites (ELAINE 2). LAS levels from ELAINE 1 and 2 were compared, while Abema, M2 and M20 plasma levels in ELAINE 2 were compared with previously reported levels. Such indirect comparisons may help determine if Abema altered the metabolism of LAS, or if LAS altered that of Abema, M2, or M20. The relationships of LAS and Abema levels with progression-free survival (PFS) were also explored. Results: Across all time points for subjects who had PK samples assessed, the LAS mean trough Css was 33.6 ng/mL (CV%, 39.8) in ELAINE 1 (n=40) and 30.9 ng/mL (CV 50.5%) in ELAINE 2 (n=29); in both studies, LAS concentrations were consistent across visits. LAS levels in ELAINE 2 were similar to those in ELAINE 1 with no evidence of accumulation. Mean (CV%) Abema plasma concentrations at weeks 2, 4, 6 and 8 were 199 (102%), 107 (130%), 82 (271%), and 94.3 (223%) ng/mL, respectively. Minimum and maximums of the mean trough Css for LAS, Abema, M2, and M20 are shown in Table 1. No relationships between LAS or Abema levels and antitumor activity measured by PFS were seen (data to be presented). Conclusion: The steady-state PK of 5 mg LAS in the ELAINE 1 and 2 studies suggest that the addition of abemaciclib to LAS did not result in an obvious or significant LAS-Abema, drug-drug interaction. Abema PK data from ELAINE 2 were consistent with published data (European Medicines Agency, Verzenio). These results support the continued development of LAS alone and combined with Abema for treating ER+/HER2-, ESR1-mutated mBC that progressed on endocrine therapy and CDK4/6 inhibitors. Table. Mean trough, steady-state concentrations of lasofoxifene and abemaciclib. XX- XX aData from patients who received oral LAS (5 mg/day) plus Abema (150 mg BID). Abema, abemaciclib; LAS, lasofoxifene; M2 and M20 are Abema metabolites. Citation Format: Senthil Damodaran, Paul V. Plourde, Simon Jenkins, Phil Mayer, David J Portman, Matthew Goetz. Pharmacokinetics (PK) of lasofoxifene (LAS) monotherapy and combined with abemaciclib (Abema) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-18-05.

Abstract PO1-05-09: ASCENT-07: A phase 3, randomized, open-label study of sacituzumab govitecan versus treatment of physician’s choice in patients with HR+/HER2– inoperable, locally advanced, or metastatic breast cancer post-endocrine therapy

Abstract Background: Approximately 70% of all breast cancer (BC) cases are hormone receptor positive/human epidermal growth factor receptor 2-negative (HR+/HER2–), with ~65% of these being HR+/HER2-low (immunohistochemistry [IHC]1+, IHC2+/in situ hybridization [ISH]–). Despite an increasing number of available endocrine and targeted treatments for metastatic disease, tumors eventually develop resistance to endocrine therapy (ET). Chemotherapy, the standard of care for patients (pts) whose cancers no longer respond to ET, is associated with poor outcomes, representing a high unmet need in the first-line endocrine-resistant setting. Sacituzumab govitecan (SG) is a Trop-2–directed antibody-drug conjugate (ADC) that delivers SN-38 (the active metabolite of the topoisomerase inhibitor irinotecan) to tumor cells via internalization, and to the surrounding tumor microenvironment via the bystander effect. SG demonstrated a significant and clinically meaningful survival benefit in the phase 3, randomized TROPiCS-02 trial, and is approved in the US for inoperable, locally advanced, or metastatic HR+/HER2– BC after ET and ≥ 2 systemic therapies in the metastatic setting. ASCENT-07 will examine the efficacy and safety of SG in the first-line chemotherapy setting, ie, in patients with inoperable, locally advanced, or metastatic ET resistant HR+/HER2– BC. Study design: ASCENT-07 (NCT05840211) is a randomized, open-label, global study evaluating SG versus treatment of physician’s choice (TPC) chemotherapy in pts with HR+/HER2– inoperable, locally advanced, or metastatic BC who have received ET and are eligible for their first chemotherapy for advanced/metastatic disease. Pts aged ≥ 18 years with histologically confirmed HR+/HER2– (HER2 IHC0 or HER2-low [IHC1+, IHC2+/ISH–]) according to ASCO/CAP criteria, measurable disease per RECIST v1.1, and ECOG performance status of 0 or 1 will be included. Pts are eligible if they meet ≥ 1 of the following criteria: progressive disease (PD) in the metastatic setting on ≥ 2 lines of ET (± targeted therapy) (disease recurrence within the first 24 months of starting adjuvant ET is considered a line of therapy), PD within 6 months of first-line ET (± CDK 4/6 inhibitor) in the metastatic setting, or disease recurrence within 24 months of adjuvant ET with CDK 4/6 inhibitor initiation and no longer a candidate for additional ET. PD on the most recent therapy will be documented by CT or MRI per RECIST v1.1. Key exclusion criteria include prior treatment targeting topoisomerase I. Pts will be randomized to SG 10 mg/kg IV on days 1 and 8 of a 21-day cycle or TPC (capecitabine, paclitaxel, nab-paclitaxel). The primary endpoint is progression-free survival (PFS) assessed by blinded independent central review (BICR) per RECIST v1.1 criteria or death from any cause, whichever comes first. Secondary endpoints include PFS (assessed by the investigator), overall survival, objective response rate and duration of response per BICR and investigator, and quality of life (QoL) assessed using the EORTC QLQ-C30 cancer questionnaire (primarily change in the Physical Functioning domain at week 16 and time to deterioration in the Global Health Status/QoL domain). Pharmacokinetics and immunogenicity analyses will be undertaken in pts receiving SG. Incidence of adverse events and serious adverse events, including relationship to study drug(s), will be reported. Laboratory and vital signs will be monitored. ASCENT-07 is currently open for recruitment and requires ~654 eligible pts to provide adequate power for assessment of the primary and key secondary endpoints. Citation Format: Hope Rugo, Javier Cortés, Giuseppe Curigliano, Carlos Barrios, Kevin Punie, Yeon Park, Hiroji Iwata, Alex Young, Xuehan Ren, Pelin Cinar, Komal Jhaveri. ASCENT-07: A phase 3, randomized, open-label study of sacituzumab govitecan versus treatment of physician’s choice in patients with HR+/HER2– inoperable, locally advanced, or metastatic breast cancer post-endocrine therapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-05-09.

A Novel RP-UHPLC-MS/MS Approach for the Determination of Tryptophan Metabolites Derivatized with 2-Bromo-4′-Nitroacetophenone

Many biologically active metabolites of the essential amino acid L-tryptophan (Trp) are associated with different neurodegenerative diseases and neurological disorders. Precise and reliable methods for their determination are needed. Variability in their physicochemical properties makes the analytical process challenging. In this case, chemical modification of analyte derivatization could come into play. Here, we introduce a novel fast reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled with tandem mass spectrometry (MS/MS) method for the determination of Trp and its ten metabolites in human plasma samples after derivatization with 2-bromo-4′-nitroacetophenone (BNAP). The derivatization procedure was optimized in terms of incubation time, temperature, concentration, and volume of the derivatization reagent. Method development comprises a choice of a suitable stationary phase, mobile phase composition, and gradient elution optimization. The developed method was validated according to the ICH guidelines. Results of all validation parameters were within the acceptance criteria of the guideline, i.e., intra- and inter-day precision (expressed as relative standard deviation; RSD) were in the range of 0.5–8.2% and 2.3–7.4%, accuracy was in the range of 93.3–109.7% and 94.7–110.1%, limits of detection (LODs) were in the range of 0.15–9.43 ng/mL, coefficients of determination (R2) were higher than 0.9906, and carryovers were, in all cases, less than 8.8%. The practicability of the method was evaluated using the blue applicability grade index (BAGI) with a score of 65. Finally, the developed method was used for the analysis of Alzheimer’s disease and healthy control plasma to prove its applicability. Statistical analysis revealed significant changes in picolinic acid (PA), anthranilic acid (AA), 5 hydroxyindole-3-acetic acid (5-OH IAA), and quinolinic acid (QA) concentration levels. This could serve as the basis for future studies that will be conducted with a large cohort of patients.