Tuberculosis remains the leading cause of death from a single infectious agent, and rising multi-drug resistance in Mycobacterium tuberculosis (Mtb) underscores the urgent need for new antibiotics. Here, we characterize BVL3572S, a hydroxamic acid-containing compound that is bactericidal against Mtb. The primary targets of BVL3572S are the pyridoxal phosphate (PLP; active form of vitamin B6)-dependent aminotransferases HisC (Rv1600) and AlaA (Rv0337c; formerly AspC), simultaneously impacting L-histidine and L-alanine biosynthesis. X-ray crystallography revealed a covalent PLP-BVL3572S adduct within the HisC active site. The formation of the adduct followed by its release suggests a futile cycle that depletes PLP. Consistently, isotopic labeling revealed widespread perturbation of amino acid biosynthesis. CRISPRi and Tn-seq analyses additionally indicated disruptions in central metabolism, cell envelope integrity, and redox balance. BVL3572S displayed strong synergy with the antitubercular drug D-cycloserine. Collectively, our findings establish BVL3572S as a promising lead compound acting through a previously unexploited, multitarget mechanism.

Tuberculosis remains the leading cause of death from a single infectious agent, and rising multi-drug resistance in Mycobacterium tuberculosis (Mtb) underscores the urgent need for new antibiotics. Here, we characterize BVL3572S, a hydroxamic acid-containing compound that is bactericidal against Mtb. The primary targets of BVL3572S are the pyridoxal phosphate (PLP; active form of vitamin B6)-dependent aminotransferases HisC (Rv1600) and AlaA (Rv0337c; formerly AspC), simultaneously impacting L-histidine and L-alanine biosynthesis. X-ray crystallography revealed a covalent PLP-BVL3572S adduct within the HisC active site. The formation of the adduct followed by its release suggests a futile cycle that depletes PLP. Consistently, isotopic labeling revealed widespread perturbation of amino acid biosynthesis. CRISPRi and Tn-seq analyses additionally indicated disruptions in central metabolism, cell envelope integrity, and redox balance. BVL3572S displayed strong synergy with the antitubercular drug D-cycloserine. Collectively, our findings establish BVL3572S as a promising lead compound acting through a previously unexploited, multitarget mechanism.

Ethionamide (Eto) and prothionamide (Pto) are second-line antibiotics used for tuberculosis (TB) treatment. Both are prodrugs whose antibacterial activity depends on bioactivation by oxidases in Mycobacterium tuberculosis, including the Baeyer-Villiger monooxygenase MymA. Through biophysical, genetic, and cellular assays, we show that the clinical candidate alpibectir (Alp, BVL-GSK098) binds the transcriptional regulator VirS, increasing MymA expression and potentiating Eto and Pto activity. Alpibectir also boosts the activity of the corresponding host-derived sulfoxide metabolites. We additionally show that alpibectir exhibits intrinsic antibacterial activity via overexpression of the mymA operon. The alpibectir/Eto (AlpE) combination is rapidly bactericidal in vitro and in mice, lowers the frequency of spontaneous resistance of Eto, and remains active on Eto- and isoniazid-resistant strains, including isolates with inhA promoter mutations. Alpibectir was safe in a Phase 1 human clinical trial. Together with the potentiation data presented here, these findings highlight its potential to optimize TB chemotherapy by reducing Eto/Pto doses, which can minimize dose-related side effects, enhancing adherence.

Background/Objectives: In vitro, vancomycin (VAN) and tetrahydrolipstatin (THL) together have been shown to synergistically inhibit Mycobacterium tuberculosis (Mtb), the world’s most infectious killer. The poor oral bioavailability of VAN and THL and predominant tropism of Mtb infection to the lungs and alveolar macrophages make pulmonary administration highly attractive. This study aimed to develop and assess the efficacy of dry powders for inhalation of VAN microparticles embedded with THL. Methods: The dry powders produced by spray-drying, with or without hydrogenated castor oil (HCO), were characterized for their physicochemical properties among others by HPLC-DAD. The fast-screening impactor was used to determine powder aerodynamic properties, and VAN and THL releases were established from the paddle over disk method. Biological activities were assessed in a new M. bovis-infected macrophage model and in Mtb-infected mice. Results and Discussion: The addition of 25% HCO enables co-deposition (fine particle dose) at the desired weight ratio and co-releasing of VAN and THL in aqueous media. Microparticles with 0% to 50% HCO drastically reduced cytoplasmic Mycobacterium bovis survival (99.9% to 62.5%, respectively), with higher efficacy at low HCO concentration. Consequently, VAN/THL with or without 25% HCO was evaluated in Mtb-infected mice. Although no decrease in Mtb lung burden was observed after two weeks of administration, the endotracheal administration of VAN 500 mg/kg and THL 50 mg/kg with 25% HCO administrated three times during five days concomitantly with daily oral rifampicin (10 mg/kg) demonstrated 2-fold bacterial burden reduction compared to the group treated with RIF alone. Conclusions: HCO was crucial for obtaining a fine particle dose at the synergistic weight ratio (VAN/THL 10:1) and for releasing both drugs in aqueous media. With oral administration of the first-line rifampicin, the dry powder VAN/THL/25% HCO was able to exert a potential anti-tubercular effect in vivo in Mtb-infected mice after five days.

Ethionamide (ETO) is a prodrug that is primarily used as a second-line agent in the treatment of tuberculosis. Among the bacterial ETO activators, the monooxygenase MymA has been recently identified, and its expression is regulated by the mycobacterial regulator VirS. The discovery of VirS ligands that can enhance mymA expression and thereby increase the antimycobacterial efficacy of ETO, has led to the development of a novel therapeutic strategy against tuberculosis. This strategy involves the selection of preclinical candidates, including SMARt751. We report the first crystal structure of the AraC-like regulator VirS, in complex with SMARt751, refined at 1.69 Å resolution. Crystals were obtained via an in situ proteolysis method in the requisite presence of SMARt751. The elucidated structure corresponds to the ligand-binding domain of VirS, adopting an α/β fold with structural similarities to H-NOX domains. Within the VirS structure, SMARt751 is situated in a completely enclosed hydrophobic cavity, where it forms hydrogen bonds with Asn11 and Asn149 as well as van der Waals contacts with various hydrophobic amino acids. Comprehensive structural comparisons within the AraC family of transcriptional regulators are conducted and analyzed to figure out the effects of the SMARt751 binding on the regulatory activity of VirS.

MabR (Rv2242), a PucR-type transcription factor, plays a crucial role in regulating mycolic acid biosynthesis in Mycobacterium tuberculosis. To understand its regulatory mechanisms, we determined the crystal structures of its N-terminal and C-terminal domains. The N-terminal domain adopts a globin-like fold, while the C-terminal domain comprises an α/β GGDEF domain and an all-α effector domain with a helix-turn-helix DNA-binding motif. This unique domain combination is specific to Actinomycetes. Biochemical and computational studies suggest that full-length MabR forms both dimeric and tetrameric assemblies in solution. Structural analysis revealed two distinct dimerization interfaces within the N- and C-terminal domains, further supporting a tetrameric organization. These findings provide valuable insights into the domain architecture, oligomeric state, and potential regulatory mechanisms of MabR.

The main objective of the present study is to estimate, through differential analysis, various biological activities of total phenolics content in alcoholic extracts of three date palm varieties sensitive or resistant to Fusarium oxysporum. sp Albidinis. Here, stilbene products with antioxidant and bioactive capacities were evidenced in resistant variety Taabdount (TAAR). Furthermore, the methanolic fraction of the TAAR-resistant date palm variety contains a significant product, determined by LC-MS/MS and 1H, 13C NMR, belonging to the family of hydroxystilbenes, which exhibits antioxidant capacities, inhibits the mushroom tyrosinase activity, and activates and exerts a protective effect on hypochlorite-induced damage in 20S proteasome of human dermal fibroblast aged cells. Altogether, the present results indicate that hydroxystilbene present in resistant Phoenix dactylifera L. should be studied to understand the way that the stilbene could exert anti-aging ability.

Apple pomace (AP) from the food industry is a mixture of different fractions containing bioactive polyphenolic compounds. This study provides a systematic approach toward the recovery and evaluation of the physiochemical and biological properties of polyphenolic compounds from AP. We studied subcritical water extraction (SCW) and solvent extraction with ethanol from four different AP fractions of pulp, peel, seed, core, and stem (A), peel (B), seed and core (C), and pulp and peel (D). The subcritical water method at the optimum condition resulted in total polyphenolic compounds (TPC) of 39.08 ± 1.10 mg GAE per g of AP on a dry basis compared to the ethanol extraction with TPC content of 10.78 ± 0.94 mg GAE/g db. Phloridzin, chlorogenic acid, and quercetin were the main identified polyphenolics in the AP fractions using HPLC. DPPH radical scavenging activity of fraction B and subcritical water (SW) extracts showed comparable activity to ascorbic acid while all ethanolic extracts were cytocompatible toward human fibroblast (3T3-L1) and salivary gland acinar cells (NS-SV-AC). Our results indicated that AP is a rich source of polyphenolics with the potential for biomedical applications.

Spathodea campanulata is used in traditional medicine to treat various ailments such as malaria, human immunodeficiency virus (HIV), cancer, fever and urethral inflammation. The aim of this study was to investigate the antiplasmodial, and antiproliferative activities of the extract and resulted fractions from S. campanulata flowers, as well as assessing the acute toxicity of its aqueous fraction. The in vitro cell-growth inhibition activities were assessed against Plasmodium falciparum strain 3D7 for antimalarial activity and three cancer cell lines: Hs683 (human oligodendroglioma), MCF7 (human breast carcinoma), and murine B16F10 (mouse melanoma) for antiproliferative activity while the in vivo acute oral toxicity was determined according to the modified organisation for Economic Co-operation and Development (OECD) guidelines 423 at a fixed dose on Female Wistar strain laboratory rats. The dichloromethane, ethyl acetate and hexane fractions at a concentration of 25 µg/mL each significantly reduced the viability of 3D7 Plasmodium cells with viability percentages of 19.0%, 14.1% and 31.9%, respectively, and IC50 of 28.1, 30.2 and 29.7 µg/mL, respectively. The ethyl acetate fraction showed a moderate antiproliferative activity on mouse melanoma with an I50 value of 54.6 µg/mL. Only the dichloromethane fraction was able to inhibit the 3 cell lines tested with IC50 values less than 15 µg/mL. An oral administration of the aqueous fraction did not induce an abnormal variation of the physiological parameters in female Wistar laboratory rats, at non-toxic doses up to 5000 mg/kg body weight for 14 days. These results confirm the use of this plant in traditional medicine for its antimalarial and anticancer potential.

The sensitivity of Mycobacterium tuberculosis , the pathogen that causes tuberculosis (TB), to antibiotic prodrugs is dependent on the efficacy of the activation process that transforms the prodrugs into their active antibacterial moieties. Various oxidases of M. tuberculosis have the potential to activate the prodrug ethionamide. Here, we used medicinal chemistry coupled with a phenotypic assay to select the N-acylated 4-phenylpiperidine compound series. The lead compound, SMARt751, interacted with the transcriptional regulator VirS of M. tuberculosis , which regulates the mymA operon encoding a monooxygenase that activates ethionamide. SMARt751 boosted the efficacy of ethionamide in vitro and in mouse models of acute and chronic TB. SMARt751 also restored full efficacy of ethionamide in mice infected with M. tuberculosis strains carrying mutations in the ethA gene, which cause ethionamide resistance in the clinic. SMARt751 was shown to be safe in tests conducted in vitro and in vivo. A model extrapolating animal pharmacokinetic and pharmacodynamic parameters to humans predicted that as little as 25 mg of SMARt751 daily would allow a fourfold reduction in the dose of ethionamide administered while retaining the same efficacy and reducing side effects.

Over the past years, natural products have been used as useful candidates for prevention and treatment of skin disorders such as skin darkening.In this current research, Daniellia oliveri which was a potential source of cosmeceutical agent was selected to investigate its active components.Daniellic acid isolated from the oleoresin was characterized by using data from 1 H-NMR, 13 C-NMR, HSQC, IR, and online chemo-informatic analysis.The daniellic acid antioxidant, anti-proliferative, and tyrosinase inhibition capabilities were evaluated.This compound possessed an anti-DPPH and iron (III) reducing effect compared to quercetin.It was able to inhibit 9 tumor cells with IC 50 going from 0.03 mM (U373) to 0.14 mM (Malme-3M).Interestingly daniellic acid inhibits tyrosinase activity with 1.20 mM as IC 50 .The tyrosinase inhibition mechanism was noncompetitive mixed-type with un-significant effect on cell melanogenesis.Daniellic acids induced a half-reduction of melanin production in B16F10 cell in IBMX stimulation (p < 0.05).The same observation was effective in Malme-3M melanin production with a significant daniellic acid action than kojic acid (p < 0.05) without reducing cell viabilities.This bioactive daniellic acid could explain the traditional uses of oleoresins from Daniellia oliveri for genitor-urinary tract diseases treatments, wound healing, and skin ailments in Burkina Faso.

The present study aimed to estimate the biological valorization potential of food saffron by-products through biological activities of phenol content in alcoholic and ethyl acetate extracts of five by-products of Crocus sativus L.: leaves, tepals, spaths, corm, and tunics. The results evidence the presence of products with bioactive capacities in cheap by-products like spaths, leaves and corms. The LC-MS/MS analysis showed methanolic fraction of stigmas contained as major products the crocins while fractions of spaths and leaves contained predominantly flavonoids. We also showed the presence of flavonols and flavones which exhibit antioxidant capacities, activate proteasome in human dermal fibroblast cells from aged donors and inhibit the growth and proteasome activity of cancer cells. Altogether, our data indicate that compounds present in saffron’s by-products, such as the leaves or spaths, might be valuable for food valorization and should be studied as a useful biological product for its anti-aging and anti-cancer abilities.

Lantana rhodesiensis Moldenke, Lippia chevalieri Moldenke, Vitex diversifolia Bak and Vitex doniana Sweet are four species of Verbenaceae family widely used in traditional medicines in Burkina. The aim of this investigation was to study the chromatographic profile of phenols acids and that of the flavonoids as well as the antioxidants activities. Then, three types of extraction were made: acetonic (100%), decoction, ethanol-water(80/20 + 20/80); and fractions of ethanol-water which arehexane fraction (HF), ethyl acetate fraction (EAF), butanol fraction (BF) and aqueous fraction (AqF) of each species. These evaluations were supplemented by the quantification of the metal ions and the characterization by atomic absorption and HPLC-DAD methods of totals phenols acids and totals flavonoids.The whole of these proportioning was directed against the antioxidant activity through the anti-DPPH* (free radical scavenging activity), anti-TAC (total antioxidant capacity) and anti-IRP(iron reducing power).36 flavonoids on 41 were highlighted by the HPLC-DAD method. A derivative glycosylate of quercetin was detected in the V. diversifolia extracts. L. chevalieri presented the strongest value in terms of ions content with a 55.88 g/kg of calcium.In terms of antioxidant activity, L. rhodesiensis and L. chevalieri presented the best activities on total antioxidant activity and anti-DPPH, and iron reducing power respectively.It’s arise that decoction extract have the best’s activities and can justify the traditional uses.

The bark of Dalbergiatrichocapra Baker is traditionally used in Madagascar as an anti-infective remedy.Beyond the recently known anti-quorum sensing (QS) properties of the D. trichocarpabark n-hexane extract, QSindependent anti-infective activities have been also detected.Indeed, chromatographic fractionation allowed the elution of fraction F1 that affects neither bacterial growth nor the expression of QS-related genes (lasB and rhlA) but significantly reduces the formation of biofilm (55.8 ± 2.3%, as compared to control conditions).Moreover,F1 is able to disrupt the structure of one-day old preformed biofilms, which consequently increases the effectiveness of an antibiotic, levofloxacin, on biofilm-encapsulated bacteria (dead bacteria in presence of levofloxacin-F1 were two-fold higher compared to levofloxacin alone).This F1-triggered disruption of biofilm formation is presumably due to an induced reduction in flagellar-dependent motilities (swimming and swarming) as well as in exopolysaccharides production.The inhibitory effect on biofilm appears reversible as the biofilm formation resumes when F1 is discarded from the culture medium.This interesting non-bactericidal mechanism of action may justify the traditional uses of D. trichocarpa in Malagasy medicine.Further work aims at identifying the compound(s) responsible for this biofilm disruption.

La phytothérapie est largement utilisée. Nous avons testé les activités hypoglycémiante et cytotoxique des feuilles de Combretum glutinosum, une plante utilisée par les tradithérapeutes en Guinée. L'activité hypoglycémiante a été comparée par Intra peritoneal glucose tolerance test (IPGTT) sur quatre groupes de 4 rats mâles Wistar Han âgés de 8-12 semaines dont le poids était compris de 191 à 296 g : G1 = extrait aqueux à la dose de 300 mg/kg ; G2 = extrait méthanolique à 300 mg/kg ; G3 = Glibenclamide à 4 mg/kg et G4 = Eau distillée à 5 ml/kg. La glycémie de chaque rat était mesurée avant l'injection du glucose (T0) puis après 5 (T5), 15 (T15), 30 (T30) et 120 min (T120) respectivement. L'activité cytotoxique des extraits dichloromethanolique et méthanolique a été testée sur 5 lignées cancéreuses humaines (A549, U373, Hs683, PC3, Kaka) et une lignée cellulaire normale (MRC-5) au moyen du test MTT en comparaison de la colonne contrôle. Les médianes de glycémies pour les 4 groupes étaient respectivement de 6,6 ; 7,2 ; 5,5 et 6,6 mmol/l à T0 ; de 8,3 ; 11,2 ; 9,9 ; 8,3 mmol/l à T15 et de 7,2 ; 6,6 ; 6,6 et 8,3 mmol/l à T120. La glycémie était maximale pour les 4 groupes à T15. La glycémie était revenue à la normale dans les groupes G1, G2 et G3 ; elle est restée significativement plus élevée dans le groupe G4 (eau distillée). L'extrait dichlorométhanolique était plus cytotoxique pour les lignées cancéreuses que pour la lignée MRC-5 (IC50 ≤ 10 μg/ml vs 20,5 μg/ml). L'extrait méthanolique n'avait pas d'activité cytotoxique (IC50 > 50 μg/ml). Ces données indiquent que les extraits aqueux et méthanolique des feuilles de C. glutinosum ont une action hypoglycémiante alors que l'extrait dichlorométhanolique a une action cytotoxique. Cette plante pourrait comme la Metformine avoir un intérêt dans le diabète et potentiellement dans le cancer.

After the publication of the article, the authors noted that they had made an error regarding certain data in their manuscript. The error relates to the statistical analysis performed for the data illustrated in Fig. 4A: On page 963 of our article, line 17 of the left-handed column, we identified an erroneous statistical result with respect to the data illustrated in Fig. 4A. The initial statistical value of ‘p<0.01’ must be corrected to ‘(p=0.06 when compared to control; Fig. 4A)’.

Glioblastoma multiforme (GBM) is a deadly cancer that possesses an intrinsic resistance to pro-apoptotic insults, such as conventional chemotherapy and radiotherapy, and diffusely invades the brain parenchyma, which renders it elusive to total surgical resection. We found that fusicoccin A, a fungal metabolite from Fusicoccum amygdali, decreased the proliferation and migration of human GBM cell lines in vitro, including several cell lines that exhibit varying degrees of resistance to pro-apoptotic stimuli. The data demonstrate that fusicoccin A inhibits GBM cell proliferation by decreasing growth rates and increasing the duration of cell division and also decreases two-dimensional (measured by quantitative video microscopy) and three-dimensional (measured by Boyden chamber assays) migration. These effects of fusicoccin A treatment translated into structural changes in actin cytoskeletal organization and a loss of GBM cell adhesion. Therefore, fusicoccin A exerts cytostatic effects but low cytotoxic effects (as demonstrated by flow cytometry). These cytostatic effects can partly be explained by the fact that fusicoccin inhibits the activities of a dozen kinases, including focal adhesion kinase (FAK), that have been implicated in cell proliferation and migration. Overexpression of FAK, a nonreceptor protein tyrosine kinase, directly correlates with the invasive phenotype of aggressive human gliomas because FAK promotes cell proliferation and migration. Fusicoccin A led to the down-regulation of FAK tyrosine phosphorylation, which occurred in both normoxic and hypoxic GBM cell culture conditions. In conclusion, the current study identifies a novel compound that could be used as a chemical template for generating cytostatic compounds designed to combat GBM.