Cytotoxic Metabolites Research Articles

Review of the fluoropyrimidine antidote uridine triacetate.

In 2015, the United States Food and Drug Administration (FDA) approved uridine triacetate to treat overdose and severe toxicity of the fluoropyrimidine chemotherapy agents 5-fluorouracil (5-FU) and its oral prodrug capecitabine. Uridine triacetate is as an oral prodrug of uridine that competes with cytotoxic fluoropyrimidine metabolites for incorporation into nucleotides. Two million people worldwide start fluoropyrimidine chemotherapy each year, with 20-30% developing severe or life-threatening adverse effects, often attributable to a genetic predisposition such as dihydropyrimidine dehydrogenase deficiency. Whilst genetic prescreening is recommended prior to starting fluoropyrimidine agents, this only prevents 20-30% of early-onset life-threatening toxicity and so does not obviate the need for an antidote. Initial in-human studies established that uridine triacetate more than doubles the maximum tolerated weekly 5-FU bolus dose. A lack of clinical equipoise meant a placebo-controlled phase III trial was not ethical and so the phase III trials used historical controls. These found that uridine triacetate improved survival in those with fluoropyrimidine overdose and severe toxicity from 16% to 94%, with 34% able to resume chemotherapy within 30 days. Five case reports of delayed fluoropyrimidine toxicity demonstrate improvement following uridine triacetate treatment 120-504 h after last fluoropyrimidine administration, suggesting efficacy beyond the FDA licencing indications. Mechanistically uridine triacetate would be expected to be effective for overdose and severe toxicity of tegafur (a 5-FU prodrug), but there are no published case reports describing this. Uridine triacetate is available internationally through an expanded access scheme and has been available in the UK since 2019 on a named patient basis.

Family Malvaceae: a potential source of secondary metabolites with chemopreventive and anticancer activities supported with in silico pharmacokinetic and pharmacodynamic profiles.

Cancer is the second most widespread cause of mortality following cardiovascular disorders, and it imposes a heavy global burden. Nowadays, herbal nutraceutical products with a plethora of bioactive metabolites represent a foundation stone for the development of promising chemopreventive and anticancer agents. Certain members of the family Malvaceae have traditionally been employed to relieve tumors. The literature concerning the chemopreventive and anticancer effects of the plant species along with the isolated cytotoxic phytometabolites was reviewed. Based on the findings, comprehensive computational modelling studies were performed to explore the pharmacokinetic and pharmacodynamic profiles of the reported cytotoxic metabolites to present basis for future plant-based anticancer drug discovery. All the available information about the anticancer research in family Malvaceae and its cytotoxic phytometabolites were retrieved from official sources. Extensive search was carried out using the keywords Malvaceae, cancer, cytotoxicity, mechanism and signalling pathway. Pharmacokinetic study was performed on the cytotoxic metabolites using SWISS ADME model. Acute oral toxicity expressed as median lethal dose (LD50) was predicted using Pro Tox 3.0 web tool. The compounds were docked using AutoDock Vina platform against epidermal growth factor receptor (EGFR kinase enzyme) obtained from the Protein Data Bank. Molecular dynamic simulations and MMGBSA calculations were performed using GROMACS 2024.2 and gmx_MMPBSA tool v1.5.2. One hundred forty-five articles were eligible in the study. Several tested compounds showed safe pharmacokinetic properties. Also, the molecular docking study showed that the bioactive metabolites possessed agreeable binding affinities to EGFR kinase enzyme. Tiliroside (25), boehmenan (30), boehmenan H (31), and isoquercetin (22) elicited the highest binding affinity toward the enzyme with a score of -10.4, -10.4, -10.2 and -10.1Kcal/mol compared to the reference drug erlotinib having a binding score equal to -9Kcal/mol. Additionally, compounds 25 and 31 elicited binding free energies equal to -42.17 and -42.68Kcal/mol, respectively, comparable to erlotinib. Overall, the current study presents helpful insights into the pharmacokinetic and pharmacodynamic properties of the reported cytotoxic metabolites belonging to family Malvaceae members. The molecular docking and dynamic simulations results intensify the roles of secondary metabolites from medicinal plants in fighting cancer.

Antioxidant and Cytoprotective Effects of Different Compounds on Cyclophosphamide-induced Nephrotoxicity

Abstract: Cyclophosphamide is a drug derived from nitrogenous mustards and is mainly indicated for the anti-neoplastic clinic. When it is metabolized in the liver, it produces acrolein, a cytotoxic metabolite capable of generating damage to the body. The oxidative, nitrative and nitrosative stress are responsible for mediating this side effect since the toxicity of the drug induces the production of reactive species of oxygen (ROS) and nitrogen (RNS). These radicals are unstable and react with other molecules that can result in cellular lesions such as lipid peroxidation, enzymatic inactivation, and excessive activation of pro-inflammatory genes, producing molecules such as malonaldehyde (MDA) and nitric oxide (NO), representing oxidative stress markers. One of the consequences of these mechanisms is nephrotoxicity. In contrast, some compounds have direct or indirect antioxidante action, which are the objects of this study: gallic acid, aminoguanidine, chrysin, hesperidine, naringin, morin-5'-sulfonic acid sodium salt and spirulina. All of them are responsible for the nephroprotective activity when administered during experiments in vitro or in vivo. Thus, this observational bibliographic research is characterized as qualitative descriptive and explanatory, since it focuses on analyzing the antioxidant properties of compounds with possible potentials to inhibit the nephrotoxicity induced by cyclophosphamide and describe the results, in addition to clarifying the biochemical activities involved in the process.

The Cytotoxic Activity and Metabolic Profiling of Hyptis rhomboidea Mart. et Gal.

Many naturally occurring chemical metabolites with significant cytotoxic activities have been isolated from medicinal plants and have become the leading hotspot of anti-cancer research in recent years. Hyptis rhomboidea Mart. et Gal is used as a folk medicine in South China to treat or assist in the treatment of liver disease, ulcers, and edema. But its chemical constituents have not been fully investigated yet. This study aimed to assess the cytotoxicity of H. rhomboidea, which was chemically characterized by chromatography-mass spectrometry methods. The results showed that the 95% ethanol extract of H. rhomboidea has marked inhibitory effects on five human cancer cell lines (HL-60, A549, SMMC-7721, MDA-MB-231, and SW480), with IC50 values ranging from 15.8 to 40.0 μg/mL. A total of 64 compounds were identified by ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and gas chromatograph-mass spectroscopy (GC-MS) analysis of H. rhomboidea crude extract. Among them, kaempferol, quercetin, rosmarinic acid, squalene, and campesterol were found to be abundant and might be the major metabolites involved to its bioactivity. The cytotoxic characterization and metabolite profiling of H. rhomboidea displayed in this research provides scientific evidence to support its use as medicinal properties.

Antibacterial and cytotoxic metabolites produced by Streptomyces tanashiensis BYF-112 isolated from Odontotermes formosanus

Chemical investigations of the termite-associated Streptomyces tanashiensis BYF-112 resulted in the discovery of four novel alkaloid derivatives: vegfrecines A and B (1 and 2), exfoliazone A (3), and venezueline H (7), in addition to nine known metabolites (4−6, 8−13). The structures of these compounds were elucidated through comprehensive spectroscopic analysis and comparison with existing literature data. Antibacterial assays revealed that viridomycin A (11) exhibited potent antibacterial activity against Staphylococcus aureus, with a zone of inhibition (ZOI) of 12.67 mm, in comparison to a ZOI of 17.67 mm for the positive control gentamicin sulfate. Viridomycin A (11) showed moderate activity against Micrococcus tetragenus and Pseudomonas syringae pv. actinidae, with ZOI values of 15.50 and 14.33 mm, respectively, which were inferior to those of gentamicin sulfate (34.67 and 24.00 mm). Viridomycin F (12) also exhibited moderate antibacterial effects against S. aureus, M. tetragenus, and P. syringae pv. actinidae, with ZOI values of 8.33, 16.50, and 10.83 mm, respectively. Cytotoxicity assays demonstrated that viridobruunine A (5), exfoliazone (6), viridomycin A (11), and X-14881E (13) exhibited significant cytotoxicity against human malignant melanoma (A375), ovarian cancer (SKOV-3), and gastric cancer (MGC-803) cell lines, with IC50 values ranging from 4.61 to 19.28 μmol·L−1. Furthermore, bioinformatic analysis of the complete genome of S. tanashiensis suggested a putative biosynthetic gene cluster (BGC) responsible for the production of compounds 1−12. These findings indicate that the secondary metabolites of insect-associated S. tanashiensis BYF-112 hold promise as potential sources of novel antibacterial and anticancer agents.

Increased SPARC in brain microvessels of ob/ob mice accelerates molecular transport into the brain accompany with albumin

Cytotoxic metabolites originating from the peripheral circulation can induce central nervous system complications associated with diabetes. Since a large proportion of these metabolites bind to plasma albumin, mechanisms for transporting albumin-metabolite complexes into the brain exist under diabetic conditions. Secreted protein acidic and rich in cysteine (SPARC) is one of the vesicular transport receptors responsible for albumin transport. This study aimed to investigate the changes in SPARC expression and cellular albumin transfer under high-glucose conditions and evaluate the permeability of molecules with high protein-bound properties to the brain tissue. Glucose (30 mM) increased SPARC expression, and intracellular albumin accumulation in NIH3T3 cells. In addition, these changes were observed in the brain of ob/ob mice. Brain microvessels function as a physiological barrier to limit the penetration of molecules from the peripheral blood circulation into the brain by forming tight junctions. Although protein expression of molecules involved in tight junction formation and cell adhesion was increased in the brain microvessels of ob/ob mice, molecular transfer into the brain through cellular junctions was not enhanced. However, Evans blue dye injected into the peripheral vein and endogenous advanced glycation end-products, exerted a high protein-binding property and accumulated in their brains. These observations indicate that peripheral molecules with high protein-binding properties invade the brain tissue and bind to albumin through transcytosis mediated by SPARC.

Phytochemical and biological investigation of Astragalus Caprinus L

Backgroundcultivated and wild plants are used to treat different ailments. The Astragalus genus is found in temperate and dry climates; thus, it is found in Egypt and the arab world. Astragalus caprinus has a good amount of bioactive chemicals, which may help explain its therapeutic effects in reducing the risk of consequences from disease.MethodThe phytochemical investigation of the herb and roots of Astragalus caprinus L. included the analytical characterization for the petroleum ether components by GC/MS, unsaponifiable matter (unsap. fraction), and fatty acids (FAME) investigation by GLC analysis. Main flavonoids were chromatographically isolated from ethyl acetate and n-butanol extracts. In vitro antimicrobial activity has been tested against the Gram-positive bacteria Staphylococcus aureus and Streptococcus mutans for different plant extracts, the Gram-negative bacteria Pseudomonas aeruginosa and Klebsiella pneumonia, the fungus Candida albicans and Aspergillus niger, and the Escherichia coli bacterium. Metabolite cytotoxicity was examined using the MTT assay against HepG-2 (human liver carcinoma) and MCF-7 (breast carcinoma).ResultsIdentifying the important components of the herb and root petroleum ether extracts was achieved. Using column chromatography, luteolin, cosmosiin (apigenin-7-O-glucoside), and cynaroside (luteolin-7-O-glucoside) were separated and identified using UV, NMR, and Mass Spectroscopy. Root extracts displayed potential antimicrobial activity against most of the tested pathogens. Both extracts (herb and roots) were active against the MCF-7 cell line and HepG-2 cell line with IC50 62.5 ± 0.64 and 72.4 ± 2.3 µg/ml, and 75.9 ± 2.5 and 96.8 ± 4.2 µg/ml, respectively.ConclusionAstragalus caprinus seems to be a promising source of bioactive compounds that could potentially aid in preventing disease complications and address common health issues in developing countries. Moreover, the various parts of this plant could be utilized as natural raw materials for producing health-boosting products that could address common health issues in developing countries.

Pharmacogenomic associations of cyclophosphamide pharmacokinetic candidate genes with 4hydroxycyclophosphamide formation in children with Cancer.

4-hydroxycyclophosphamide (4HCY) is the principal precursor to the cytotoxic metabolite of cyclophosphamide (CY), which is often used as first-line treatment of children with cancer. There is conflicting data regarding the relationship between CY efficacy, toxicity, and pharmacokinetics with the genes encoding proteins involved in 4HCY pharmacokinetics, specifically its formation and elimination. We evaluated germline pharmacogenetics in children with various malignancies receiving their first CY dose. Using linear regression, we analyzed the associations between two pharmacokinetic outcomes - how fast a child cleared CY (i.e., CY clearance) and the ratio of the 4HCY/CY exposure, specifically area under the plasma concentration-time curve (AUC), and 372 single nucleotide polymorphisms (SNP) in 14 drug-metabolizing transporters or enzymes involved in 4HCY formation or elimination. Age was associated with the ratio of 4HCY/CY AUC (P = 0.004); Chemotherapy regimen was associated with CY clearance (P = 0.003). No SNPs were associated with CY clearance or the ratio of 4HCY/CY AUC after controlling for a false discovery rate. Age and chemotherapy regimen, but not germline pharmacogenomics, were associated with CY clearance or the ratio of 4HCY/CY AUC. Other methods, such as metabolomics or lipidomics, should be explored.

Ammonia transporter RhBG initiates downstream signaling and functional responses by activating NFκB

Transceptors, solute transporters that facilitate intracellular entry of molecules and also initiate intracellular signaling events, have been primarily studied in lower-order species. Ammonia, a cytotoxic endogenous metabolite, is converted to urea in hepatocytes for urinary excretion in mammals. During hyperammonemia, when hepatic metabolism is impaired, nonureagenic ammonia disposal occurs primarily in skeletal muscle. Increased ammonia uptake in skeletal muscle is mediated by a membrane-bound, 12 transmembrane domain solute transporter, Rhesus blood group-associated B glycoprotein (RhBG). We show that in addition to its transport function, RhBG interacts with myeloid differentiation primary response-88 (MyD88) to initiate an intracellular signaling cascade that culminates in activation of NFκB. We also show that ammonia-induced MyD88 signaling is independent of the canonical toll-like receptor-initiated mechanism of MyD88-dependent NFκB activation. In silico, in vitro, and in situ experiments show that the conserved cytosolic J-domain of the RhBG protein interacts with the Toll-interleukin-1 receptor (TIR) domain of MyD88. In skeletal muscle from human patients, human-induced pluripotent stem cell-derived myotubes, and myobundles show an interaction of RhBG-MyD88 during hyperammonemia. Using complementary experimental and multiomics analyses in murine myotubes and mice with muscle-specific RhBG or MyD88 deletion, we show that the RhBG-MyD88 interaction is essential for the activation of NFkB but not ammonia transport. Our studies show a paradigm of substrate-dependent regulation of transceptor function with the potential for modulation of cellular responses in mammalian systems by decoupling transport and signaling functions of transceptors.

Exploring the ethnopharmacological significance of Cynara scolymus bracts: Integrating metabolomics, in-Vitro cytotoxic studies and network pharmacology for liver and breast anticancer activity assessment

Ethnopharmacological relevanceLiver and breast cancers are the most dominant cancer types with high occurrence rates. Artichoke (Cynara scolymus L.) has been reputed for its traditional use in alleviating many liver and gallbladder ailments beside its anticancer activity against various types of cancer cells. Aim of the studyTo demonstrate detailed chemical matrices of the different plant parts and evaluate their cytotoxic activities aiming to unveil the relationship between these activities and the intrinsic metabolites using metabolomic studies, in-vitro experiments and network pharmacology. Materials and methodsChemical profiling of extracts from the different plant parts (stems, leaves, bracts and receptacles) was performed using HPLC/QqQ/MS followed by unsupervised chemometric studies. In-vitro cytotoxic potentials of the extracts were evaluated on breast and liver cancer cell line then an OPLS study using linear regression was conducted. Consequently, a network pharmacology analysis on the most bioactive plant organ was applied. ResultsUnsupervised chemometric analysis revealed that kaempferol-3-O-α-L-rhamnopyranoside-7-O-β-D-galacturonopyranoside, chrysoeriol-7-rutinoside and 1-caffeoylquinic acid were responsible for the segregation of the bract (CSB) segregated from the rest of the plant organs. Interestingly, CSB extract possessed the highest potential in-vitro cytotoxic activity against both liver and breast cancer cells (IC50 = 1.65 and 1.77 μg/mL). As expected, the aforementioned biomarkers were observed to be the discriminatory cytotoxic metabolites in the constructed supervised chemometric model. Network pharmacology analysis on CSB revealed 27 liver cancer-related metabolites of which, 1-caffeoylquinic acid was the most enriched one contributing to 13% of the total interactions. Furthermore, 38 target genes were involved, the most enriched of which were Aldo-keto reductase family 1 member B1 (AKR1B10) and interleukin-2 (IL-2). KEGG pathway analysis unveiled 23 significantly related pathways including metabolic pathways that possessed the lowest p-value (1.6E-5). ConclusionThe findings demonstrated that CSB is a significant source of cytotoxic metabolites against breast cancer and liver cancer cell lines, hence, drawing attention to the pharmaceutical and medicinal value of this negligible plant organ and paving the route for insightful research into its exact pharmacological cytotoxic mechanisms.

Synthesis of Nitrostyrylthiazolidine-2,4-dione Derivatives Displaying Antileishmanial Potential.

A series of 61 thiazolidine-2,4-diones bearing a styryl group at position 5 was synthesized in 2-5 steps and their structure was proved by elemental and spectral analyses. The compounds obtained were evaluated in vitro against the promastigote stage of the kinetoplastid parasite Leishmania infantum and the human HepG2 cell line, to determine selectivity indices and to compare their activities with those of antileishmanial reference drugs. The study of structure-activity relationships indicated the potential of some derivatives bearing a nitro group on the phenyl ring, especially when located at the meta position. Thus, among the tested series, compound 14c appeared as a hit compound with good antileishmanial activity (EC50 = 7 µM) and low cytotoxicity against both the hepatic HepG2 and macrophage THP-1 human cell lines (CC50 = 101 and 121 µM, respectively), leading to good selectivity indices (respectively, 14 and 17), in comparison with the reference antileishmanial drug compound miltefosine (EC50 = 3.3 µM, CC50 = 85 and 30 µM, SI = 26 and 9). Regarding its mechanism of action, among several possibilities, it was demonstrated that compound 14c is a prodrug bioactivated, predominantly by L. donovani nitroreductase 1, likely leading to the formation of cytotoxic metabolites that form covalent adducts in the parasite. Finally, compound 14c is lipophilic (measured CHI LogD7.7 = 2.85) but remains soluble in water (measured PBS solubility at pH7.4 = 16 µM), highlighting the antileishmanial potential of the nitrostyrylthiazolidine-2,4-dione scaffold.

Effects of species of origin and mode of induction of microsomes on carbamazepine-induced cell toxicity

Standardization and validation of in vitro drug metabolism is essential for pre-clinical drug development as well as for in vitro toxicity assays including the lymphocyte toxicity assay (LTA) and the in vitro platelet toxicity assay (iPTA). Use of isolated liver microsomes (MIC) in in vitro testing has been utilized for a long time; however, the effect of species of origin and induction agents on the metabolic capacities of MIC is not adequately evaluated. In this study we investigated the impact of species of origin and induction agent on the capacity of MICs to bioactivate carbamazepine (CBZ) using cytotoxicity as a gross endpoint to measure the levels of cytotoxic metabolites generated by each type of MICs. Jurkat E6.1 cell line was used and MICs from human, rat, mouse, minipig and rabbit origin as well as rat MICs that is either non-induced or induced by phenobarbitone (PHB), dexamethasone (DEXA), 3-methylcholanthrene (3MC), clofibrate (CLOF) and isoniazid (INH) were investigated. MICs from minipig and rat MICs induced with 3MC exhibited the highest capacity to produce cytotoxic metabolites of CBZ. These findings will help optimize and standardize in vitro toxicity assays and provide guidance to pre-clinical investigation of drugs.

Marine Prostanoids with Cytotoxic Activity from Octocoral Clavularia spp.

Octocoral of the genus Clavularia is a kind of marine invertebrate possessing abundant cytotoxic secondary metabolites, such as prostanoids and dolabellanes. In our continuous natural product study of C. spp., two previously undescribed prostanoids [clavulone I-15-one (1) and 12-O-deacetylclavulone I (2)] and eleven known analogs (3-13) were identified. The structures of these new compounds were elucidated based on analysis of their 1D and 2D NMR, HRESIMS, and IR data. Additionally, all tested prostanoids (1 and 3-13) showed potent cytotoxic activities against the human oral cancer cell line (Ca9-22). The major compound 3 showed cytotoxic activity against the Ca9-22 cells with the IC50 value of 2.11 ± 0.03 μg/mL, which echoes the cytotoxic effect of the coral extract. In addition, in silico tools were used to predict the possible effects of isolated compounds on human tumor cell lines and nitric oxide production, as well as the pharmacological potentials.

Cytotoxic and antimicrobial metabolites from the marine-derived fungus Aspergillus sp. OPR23-FS01

Chemical investigation of a marine-derived fungus Aspergillus sp. OPR23-FS01 resulted in the isolation of a new unsaturated fatty acid featuring a terminal olefin, 10-methoxy-2-methylene-10-oxodecanoic acid (1), two new natural compounds, 2-carboxy-2′-methyl-azobenzene (2) and 1,3,9-trimethyluric acid (3), and 11 previously described metabolites, pantheric acid C (4), pantheric acid D (5), 2-furoic acid (6), 5-(hydroxymethyl)-2-furancarboxylic acid (7), sporogen-AO 1 (8), gliocladic acid (9), hydroheptelidic acid (10), ditryptophenaline (11), emodin (12), uridine (13), and thymidine (14). Their structures were identified by comprehensive analyses of the spectroscopic methods, including NMR and HRESI mass spectra. Compound 2 possesses a rare diazenyl group among the previously reported fungal metabolites. Compound 8 showed significant cytotoxicity against both HepG2 and MCF-7 cell lines in a dose-dependent manner, with IC50 values of 4.66 ± 0.24 and 5.54 ± 0.28 μM, respectively. Compounds 1−5 and 8−11 displayed antimicrobial effect against Enterococcus faecalis ATCC299212, with MIC values ranging from 32 to 128 μM, whereas 1, 4, 5, and 8−11 inhibited Candida albicans ATCC10231 growth, with MIC values in a range of 32–256 μM.

Bioassay-guided isolation of cytotoxic metabolites from Daphne mucronata and evaluate of apoptosis inductive effect on potent compound

Bioassay-guided isolation of cytotoxic metabolites from Daphne mucronata and evaluate of apoptosis inductive effect on potent compound

Comparison of efficacy and safety of 5-FU or capecitabine combined with cisplatin and docetaxel (mDCF and mDCX) as a first-line chemotherapy regimen in her 2-negative metastatic gastric cancer patients: A retrospective study.

The prognosis of metastatic gastric cancer (GC) is poor, with a median survival time of less than a year. Capecitabine is a prodrug, metabolized by thymidine phosphorylase to its cytotoxic metabolite (5-FU). Few studies have compared capecitabine and 5-FU in mGC. In this retrospective study, we compared the efficacy and safety of modified DCF (mDCF) (docetaxel, cisplatin, and 5-FU) and modified DCX (mDCX) (docetaxel, cisplatin, and capecitabine) regimens for first-line treatment in patients with mGC. The study included 112 mGC patients treated with either mDCF (n = 69) or mDCX (n = 43) between 2010 and 2021. Demographic data, response rate, progression-free survival (PFS), overall survival (OS), and adverse events were evaluated. The complete response rate in the mDCF group was 10.1%, whereas the complete response rate in the mDCX group was 2.3%. The partial response rate for mDCF and mDCX were 29% and 37%, respectively. The 2 treatment arms of the study had the same objective rate of response and disease control rate (DCR). PFS and OS rates were comparable between the 2 groups. The median PFS in the mDCF and mDCX arms were 6.0 months (95% CI, 4.87-7.14) and 5.0 months (95% CI, 4.10-5.90) respectively (P = .08). The median OS in the mDCF and mDCX arms were 9.0 months (95% CI, 7.53-10.47) and 9.0 months (95% CI, 6.87-11.11) respectively (P = .07). Neutropenia, asthenia, stomatitis, and nausea/vomiting were the most frequently reported grade 3 to 4 adverse events (AEs). The rates of grade 3/4 AEs and dose reduction were comparable between the 2 groups. There was no treatment discontinuation due to grade 3 to 4 AE. As a first-line treatment for patients with mGC, mDCX and mDCF regimens have comparable efficacy and tolerability profiles.

Biosynthesis of the Azoxy Compound Azodyrecin from Streptomyces mirabilis P8-A2.

Azoxy compounds are a distinctive group of bioactive secondary metabolites characterized by a unique RN═N+(O-)R moiety. The azoxy moiety is present in various classes of metabolites that exhibit various biological activities. The enzymatic mechanisms underlying azoxy bond formation remain enigmatic. Azodyrecins are cytotoxic azoxy metabolites produced by Streptomyces mirabilis P8-A2. Here, we cloned and confirmed the putative azd biosynthetic gene cluster through CATCH cloning followed by expression and production of azodyrecins in two heterologous hosts, S. albidoflavus J1074 and S. coelicolor M1146, respectively. We explored the function of 14 enzymes in azodyrecin biosynthesis through gene knockout using CRISPR-Cas9 base editing in the native producer, S. mirabilis P8-A2. The key intermediates were analyzed in the mutants through MS/MS fragmentation studies, revealing azoxy bond formation via the conversion of hydrazine to an azo compound followed by further oxygenation. Enzymes involved in modifications of the precursor could be postulated based on their predicted function and the intermediates identified in the knockout strains. Moreover, the distribution of the azoxy biosynthetic gene clusters across Streptomyces spp. genomes is explored, highlighting the presence of these clusters in over 20% of the Streptomyces spp. genomes and revealing that azoxymycin and valanimycin are scarce, while azodyrecin and KA57A-like clusters are widely distributed across the phylogenetic tree.

A Set of Screening Techniques for a Quick Overview of the Neutrophil Function.

Neutrophils are known as one of the first lines of defense in the innate immune response and can perform many particular cellular functions, such as chemotaxis, reverse migration, phagocytosis, degranulation of cytotoxic enzymes and metabolites, and release of DNA as neutrophil extracellular traps (NETs). Neutrophils not only have tightly regulated signaling themselves, but also participate in the regulation of other components of the immune system. As fresh neutrophils are terminally differentiated, short-lived, and highly variable among individuals, it is important to make the most of the collected samples. Researchers often need to perform screening assays to assess an overview of the many neutrophil functions that may be affected by specific conditions under evaluation. A set of tests following a single isolation process of normal density neutrophils was developed to address this need, seeking a balance between speed, comprehensiveness, cost, and accuracy. The results can be used to reason and guide in-depth follow-up studies. This procedure can be carried out in an average time of 4 h and includes the evaluation of cell viability, reactive oxygen species (ROS) production, real-time migration, and phagocytosis of yeast on glass slides, leaving enough cells for more detailed approaches like omics studies. Moreover, the procedure includes a way to easily observe a preliminary suggestion of NETs after fast panoptic staining observed by light microscopy, with a lack of specific markers, albeit enough to indicate if further efforts in that way would be worthwhile. The diversity of functions tested combines common points among tests, reducing the analysis time and expenses. The procedure was named NeutroFun Screen, and although havinglimitations, it balances the aforementioned factors. Furthermore, the aim of this work is not a definite test set, but rather a guideline that can easily be adjusted to each lab's resources and demands.

Metabolites Profile of Extracts and Fractions of Erythroxylum mexicanum Kunth by UHPLC-QTOF-MS/MS and its Antibacterial, Cytotoxic and Nitric Oxide Inhibitory Activities.

The present study shows the untargeted metabolite profiling and in vitro antibacterial, cytotoxic, and nitric oxide (NO) inhibitory activities of the methanolic leaves extract (MLE) and methanolic stem extract (MSE) of Erythroxylum mexicanum, as well as the fractions from MSE. Using ultra-high performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS), a total of 70 metabolites were identified; mainly alkaloids in the MLE, while the MSE showed a high abundance of diterpenoids. The MSE fractions exhibited differential activity against Gram-positive bacteria. Notably, the hexane fraction (HSF) against Streptococcus pyogenes ATCC 19615 (MIC=62.5 μg/mL) exhibited a bactericidal effect. The MSE fractions exhibited cytotoxicity against all cancer cell lines tested, with selectivity towards them compared to a noncancerous cell line. Particularly, the HSF and chloroform fraction (CSF) showed the highest cytotoxicity against prostate cancer (PC-3) cells, with IC50 values of 19.9 and 18.1 μg/mL and selectivity indexes of 3.8 and 4.2, respectively. Both the HSF and ethyl acetate (EASF) fractions of the MSE inhibited NO production in RAW 264.7 macrophages, with NO production percentages of 50.0 % and 51.7 %, respectively, at a concentration of 30 μg/mL. These results indicated that E. mexicanum can be a source of antibacterial, cytotoxic, and anti-inflammatory metabolites.

Cytotoxic metabolites from Sinularia levi supported by network pharmacology.

The in-vitro anti-proliferative evaluation of Sinularia levi total extract against three cell lines revealed its potent effect against Caco-2 cell line with IC50 3.3 μg/mL, followed by MCF-7 and HepG-2 with IC50 6.4 μg/mL and 8.5 μg/mL, respectively, in comparison to doxorubicin. Metabolic profiling of S. levi total extract using liquid chromatography coupled with high-resolution electrospray ionization mass spectrometry (LC-HR-ESI-MS) revealed the presence of phytoconstituents clusters consisting mainly of steroids and terpenoids (1-20), together with five metabolites 21-25, which were additionally isolated and identified through the phytochemical investigation of S. levi total extract through various chromatographic and spectroscopic techniques. The isolated metabolites included one sesquiterpene, two steroids and two diterpenes, among which compounds prostantherol (21) and 12-hydroperoxylsarcoph-10-ene (25) were reported for the first time in Sinularia genus. The cytotoxic potential evaluation of the isolated compounds revealed variable cytotoxic effects against the three tested cell lines. Compound 25 was the most potent with IC50 value of 2.13 ± 0.09, 3.54 ± 0.07 and 5.67 ± 0.08 μg/mL against HepG-2, MCF-7 and Caco-2, respectively, followed by gorgosterol (23) and sarcophine (24). Additionally, network analysis showed that cyclin-dependent kinase 1 (CDK1) was encountered in the mechanism of action of the three cancer types. Molecular docking analysis revealed that CDK1 inhibition could possibly be the reason for the cytotoxic potential.