Evolutionary relevance of metabolite production in relation to marine sponge bacteria symbiont.

Sponges are habitats for a diverse community of microorganisms. Sponges provide shelter, whereas microbes provide a complementary defensive mechanism. Here, a symbiotic bacterium, identified as Bacillus spp., was isolated from a marine sponge following culture enrichment. Fermentation-assisted metabolomics using thin-layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS) indicated that marine simulated nutrition and temperature was the optimum in metabolite production represented by the highest number of metabolites and the diverse chemical classes when compared to other culture media. Following large-scale culture in potato dextrose broth (PDB) and dereplication, compound M1 was isolated and identified as octadecyl-1-(2',6'-di-tert-butyl-1'-hydroxyphenyl) propionate. M1, at screening concentrations up to 10 mg/ml, showed no activity against prokaryotic bacteria including Staphylococcus aureus and Escherichia coli, while 1 mg/ml of M1 was sufficient to cause a significant killing effect on eukaryotic cells including Candida albicans, Candida auris, and Rhizopus delemar fungi and different mammalian cells. M1 exhibited MIC50 0.97 ± 0.006 and 7.667 ± 0.079 mg/ml against C. albicans and C. auris, respectively. Like fatty acid esters, we hypothesize that M1 is stored in a less harmful form and upon pathogenic attack is hydrolyzed to a more active form as a defensive metabolite. Subsequently, [3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid] (DTBPA), the hydrolysis product of M1, exhibited ~ 8-fold and 18-fold more antifungal activity than M1 against C. albicans and C. auris, respectively. These findings indicated the selectivity of that compound as a defensive metabolite towards the eukaryotic cells particularly the fungi, a major infectious agent to sponges. Metabolomic-assisted fermentation can provide a significant understanding of a triple marine-evolved interaction. KEY POINTS: • Bacillus species, closely related to uncultured Bacillus, is isolated from Gulf marine sponge • Metabolomic-assisted fermentations showed diverse metabolites • An ester with a killing effect against eukaryotes but not prokaryotes is isolated.

Design, Synthesis, and Potent Anticancer Activity of Novel Indole-Based Bcl-2 Inhibitors.

The Bcl-2 family plays a crucial role in regulating cell apoptosis, making it an attractive target for cancer therapy. In this study, a series of indole-based compounds, U1-6, were designed, synthesized, and evaluated for their anticancer activity against Bcl-2-expressing cancer cell lines. The binding affinity, safety profile, cell cycle arrest, and apoptosis effects of the compounds were tested. The designed compounds exhibited potent inhibitory activity at sub-micromolar IC50 concentrations against MCF-7, MDA-MB-231, and A549 cell lines. Notably, U2 and U3 demonstrated the highest activity, particularly against MCF-7 cells. Respectively, both U2 and U3 showed potential BCL-2 inhibition activity with IC50 values of 1.2 ± 0.02 and 11.10 ± 0.07 µM using an ELISA binding assay compared with 0.62 ± 0.01 µM for gossypol, employed as a positive control. Molecular docking analysis suggested stable interactions of compound U2 at the Bcl-2 binding site through hydrogen bonding, pi-pi stacking, and hydrophobic interactions. Furthermore, U2 demonstrated significant induction of apoptosis and cell cycle arrest at the G1/S phase. Importantly, U2 displayed a favourable safety profile on HDF human dermal normal fibroblast cells at 10-fold greater IC50 values compared with MDA-MB-231 cells. These findings underscore the therapeutic potential of compound U2 as a Bcl-2 inhibitor and provide insights into its molecular mechanisms of action.

Flavonoids are promising safe therapy against COVID-19.

Flavonoids are a class of phenolic natural products, well-identified in traditional and modern medicines in the treatment of several diseases including viral infection. Flavonoids showed potential inhibitory activity against coronaviruses including the current pandemic outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and designated as COVID-19. Here, we have collected all data related to the potential inhibitory mechanisms of flavonoids against SARS-CoV-2 infection and their significant immunomodulatory activities. The data were mapped and compared to elect major flavonoids with a promising role in the current pandemic. Further, we have linked the global existence of flavonoids in medicinal plants and their role in protection against COVID-19. Computational analysis predicted that flavonoids can exhibit potential inhibitory activity against SARS-CoV-2 by binding to essential viral targets required in virus entry and/ or replication. Flavonoids also showed excellent immunomodulatory and anti-inflammatory activities including the inhibition of various inflammatory cytokines. Further, flavonoids showed significant ability to reduce the exacerbation of COVID-19 in the case of obesity via promoting lipids metabolism. Moreover, flavonoids exhibit a high safety profile, suitable bioavailability, and no significant adverse effects. For instance, plants rich in flavonoids are globally distributed and can offer great protection from COVID-19. The data described in this study strongly highlighted that flavonoids particularly quercetin and luteolin can exhibit promising multi-target activity against SARS-CoV-2, which promote their use in the current and expected future outbreaks. Therefore, a regimen of flavonoid-rich plants can be recommended to supplement a sufficient amount of flavonoids for the protection and treatment from SARS-CoV-2 infection.

Lipid-based therapies against SARS-CoV-2 infection.

Viruses have evolved to manipulate host lipid metabolism to benefit their replication cycle. Enveloped viruses, including coronaviruses, use host lipids in various stages of the viral life cycle, particularly in the formation of replication compartments and envelopes. Host lipids are utilised by the virus in receptor binding, viral fusion and entry, as well as viral replication. Association of dyslipidaemia with the pathological development of Covid-19 raises the possibility that exploitation of host lipid metabolism might have therapeutic benefit against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, promising host lipid targets are discussed along with potential inhibitors. In addition, specific host lipids are involved in the inflammatory responses due to viral infection, so lipid supplementation represents another potential strategy to counteract the severity of viral infection. Furthermore, switching the lipid metabolism through a ketogenic diet is another potential way of limiting the effects of viral infection. Taken together, restricting the access of host lipids to the virus, either by using lipid inhibitors or supplementation with exogenous lipids, might significantly limit SARS-CoV-2 infection and/or severity.

Comparative evaluation of flavonoids reveals the superiority and promising inhibition activity of silibinin against SARS-CoV-2.

Flavonoids are phenolic compounds naturally found in plants and commonly consumed in diets. Herein, flavonoids were sequentially evaluated by a comparative in silico study associated with systematic literature search. This was followed by an in vitro study and enzyme inhibition assays against vital SARS-CoV-2 proteins including spike (S) protein, main protease (Mpro ), RNA-dependent RNA-polymerase (RdRp), and human transmembrane serine protease (TMPRSS2). The results obtained revealed 10 flavonoids with potential antiviral activity. Out of them, silibinin showed promising selectivity index against SARS-CoV-2 in vitro. Screening against S protein discloses the highest inhibition activity of silibinin. Mapping the activity of silibinin indicated its excellent binding inhibition activity against SARS-CoV-2 S protein, Mpro and RdRP at IC50 0.029, 0.021, and 0.042 µM, respectively, while it showed no inhibition activity against TMPRSS2 at its IC50(SARS-CoV-2) . Silibinin was tested safe on human mammalian cells at >7-fold its IC50(SARS-CoV-2) . Additionally, silibinin exhibited >90% virucidal activity at 0.031 µM. Comparative molecular docking (MD) showed that silibinin possesses the highest binding affinity to S protein and RdRP at -7.78 and -7.15 kcal/mol, respectively. MDs showed that silibinin exhibited stable interaction with key amino acids of SARS-CoV-2 targets. Collectively, silibinin, an FDA-approved drug, can significantly interfere with SARS-CoV-2 entry and replication through multi-targeting activity.

Promising anti-SARS-CoV-2 drugs by effective dual targeting against the viral and host proteases.

SARS-CoV-2 caused dramatic health, social and economic threats to the globe. With this threat, the expectation of future outbreak, and the shortage of anti-viral drugs, scientists were challenged to develop novel antivirals. The objective of this study is to develop novel anti-SARS-CoV-2 compounds with dual activity by targeting valuable less-mutated enzymes. Here, we have mapped the binding affinity of >500,000 compounds for potential activity against SARS-CoV-2 main protease (Mpro), papain protease (PLpro) and human furin protease. The enzyme inhibition activity of most promising hits was screened and tested in vitro on SARS-CoV-2 clinical isolate incubated with Vero cells. Computational modelling and toxicity of the compounds were validated. The results revealed that 16 compounds showed potential binding activity against Mpro, two of them showed binding affinity against PLpro and furin protease. Respectively, compounds 7 and 13 showed inhibition activity against Mpro at IC50 0.45 and 0.11 µM, against PLpro at IC50 0.085 and 0.063 µM, and against furin protease at IC50 0.29 µM. Computational modelling validated the binding affinity against all proteases. Compounds 7 and 13 showed significant inhibition activity against the virus at IC50 0.77 and 0.11 µM, respectively. Both compounds showed no toxicity on mammalian cells. The data obtained indicated that compounds 7 and 13 exhibited potent dual inhibition activity against SARS-CoV-2. The dual activity of both compounds can be of great promise not only during the current pandemic but also for future outbreaks since the compounds' targets are of limited mutation and critical importance to the viral infection.

Selective inhibition of Rhizopus eumelanin biosynthesis by novel natural product scaffold-based designs caused significant inhibition of fungal pathogenesis.

Melanin is a dark color pigment biosynthesized naturally in most living organisms. Fungal melanin is a major putative virulence factor of Mucorales fungi that allows intracellular persistence by inducing phagosome maturation arrest. Recently, it has been shown that the black pigments of Rhizopus delemar is of eumelanin type, that requires the involvement of tyrosinase (a copper-dependent enzyme) in its biosynthesis. Herein, we have developed a series of compounds (UOSC-1-14) to selectively target Rhizopus melanin and explored this mechanism therapeutically. The compounds were designed based on the scaffold of the natural product, cuminaldehyde, identified from plant sources and has been shown to develop non-selective inhibition of melanin production. While all synthesized compounds showed significant inhibition of Rhizopus melanin production and limited toxicity to mammalian cells, only four compounds (UOSC-1, 2, 13, and 14) were selected as promising candidates based on their selective inhibition to fungal melanin. The activity of compound UOSC-2 was comparable to the positive control kojic acid. The selected candidates showed significant inhibition of Rhizopus melanin but not human melanin by targeting the fungal tyrosinase, and with an IC50 that are 9 times lower than the reference standard, kojic acid. Furthermore, the produced white spores were phagocytized easily and cleared faster from the lungs of infected immunocompetent mice and from the human macrophages when compared with wild-type spores. Collectively, the results suggested that the newly designed derivatives, particularly UOSC-2 can serve as promising candidate to overcome persistence mechanisms of fungal melanin production and hence make them accessible to host defenses.

Iterated Virtual Screening-Assisted Antiviral and Enzyme Inhibition Assays Reveal the Discovery of Novel Promising Anti-SARS-CoV-2 with Dual Activity.

Unfortunately, COVID-19 is still a threat to humankind and has a dramatic impact on human health, social life, the world economy, and food security. With the limited number of suggested therapies under clinical trials, the discovery of novel therapeutic agents is essential. Here, a previously identified anti-SARS-CoV-2 compound named Compound 13 (1,2,5-Oxadiazole-3-carboximidic acid, 4,4'-(methylenediimino) bis,bis[[(2-hydroxyphenyl)methylene]hydrazide) was subjected to an iterated virtual screening against SARS-CoV-2 Mpro using a combination of Ligand Designer and PathFinder. PathFinder, a computational reaction enumeration tool, was used for the rapid generation of enumerated structures via default reaction library. Ligand designer was employed for the computerized lead optimization and selection of the best structural modification that resulted in a favorable ligand-protein complex. The obtained compounds that showed the best binding to Mpro were re-screened against TMPRSS2, leading to the identification of 20 shared compounds. The compounds were further visually inspected, which resulted in the identification of five shared compounds M1-5 with dual binding affinity. In vitro evaluation and enzyme inhibition assay indicated that M3, an analogue of Compound 13 afforded by replacing the phenolic moiety with pyridinyl, possesses an improved antiviral activity and safety. M3 displayed in vitro antiviral activity with IC50 0.016 µM and Mpro inhibition activity with IC50 0.013 µM, 7-fold more potent than the parent Compound 13 and potent than the antivirals drugs that are currently under clinical trials. Moreover, M3 showed potent activity against human TMPRSS2 and furin enzymes with IC50 0.05, and 0.08 µM, respectively. Molecular docking, WaterMap analysis, molecular dynamics simulation, and R-group analysis confirmed the superiority of the binding fit to M3 with the target enzymes. WaterMap analysis calculated the thermodynamic properties of the hydration site in the binding pocket that significantly affects the biological activity. Loading M3 on zinc oxide nanoparticles (ZnO NPs) increased the antiviral activity of the compound 1.5-fold, while maintaining a higher safety profile. In conclusion, lead optimized discovery following an iterated virtual screening in association with molecular docking and biological evaluation revealed a novel compound named M3 with promising dual activity against SARS-CoV-2. The compound deserves further investigation for potential clinical-based studies.

New Bioactive Fused Triazolothiadiazoles as Bcl-2-Targeted Anticancer Agents.

A series of 3-(6-substituted phenyl-[1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazol-3-yl)-1H-indoles (5a-l) were designed, synthesized and evaluated for anti-apoptotic Bcl-2-inhibitory activity. Synthesis of the target compounds was readily accomplished through a reaction of acyl hydrazide (1) with carbon disulfide in the presence of alcoholic potassium hydroxide to afford the corresponding intermediate potassium thiocarbamate salt (2), which underwent cyclization reaction in the presence of excess hydrazine hydrate to the corresponding triazole thiol (3). Further cyclisation reaction with substituted benzoyl chloride derivatives in the presence of phosphorous oxychloride afforded the final 6-phenyl-indol-3-yl [1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazole compounds (5a-l). The novel series showed selective sub-micromolar IC50 growth-inhibitory activity against Bcl-2-expressing human cancer cell lines. The most potent 6-(2,4-dimethoxyphenyl) substituted analogue (5k) showed selective IC50 values of 0.31-0.7 µM against Bcl-2-expressing cell lines without inhibiting the Bcl-2-negative cell line (Jurkat). ELISA binding affinity assay (interruption of Bcl-2-Bim interaction) showed potent binding affinity for (5k) with an IC50 value of 0.32 µM. Moreover, it fulfils drug likeness criteria as a promising drug candidate.

Estimating the viral loads of SARS-CoV-2 in the oral cavity when complicated with periapical lesions.

BACKGROUND: The oral cavity represents a main entrance of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Angiotensin-converting enzyme 2 (ACE-2), neuropilin-1 (NRP-1), and transmembrane serine protease 2 (TMPRSS2) are essential for the entry of SARS-CoV-2 to the host cells. Both ACE-2 and NRP-1 receptors and TMPRSS2 have been identified in the oral cavity. However, there is limited knowledge about the impact of periapical lesions and their metabolites on the expression of these critical genes. This study aims to measure the impact of periapical lesions and their unique fatty acids (FAs) metabolites on the expression of the aforementioned genes, in addition to interleukin 6 (IL-6) gene and hence SARS-CoV-2 infection loads can be estimated. METHODS: Gene expression of ACE-2, NRP-1, TMPRSS2, and IL-6 was performed in periapical lesions in comparison to healthy oral cavity. Since FAs are important immunomodulators required for the lipid synthesis essential for receptors synthesis and viral replication, comparative FAs profiling was determined in oral lesions and healthy pulp tissues using gas chromatography-mass spectrometry (GC-MS). The effect of major identified and unique FAs was tested on mammalian cells known to express ACE-2, NRP-1, and TMPRSS2 genes. RESULTS: Gene expression analysis indicated that ACE-2, NRP-1, and TMPRSS2 were significantly upregulated in healthy clinical samples compared to oral lesions, while the reverse was true with IL-6 gene expression. Saturated and monounsaturated FAs were the major identified shared and unique FAs, respectively. Major shared FAs included palmitic, stearic and myristic acids with the highest percentage in the healthy oral cavity, while unique FAs included 17-octadecynoic acid in periapical abscess, petroselinic acid and L-lactic acid in periapical granuloma, and 1-nonadecene in the radicular cyst. Computational prediction showed that the binding affinity of identified FAs to ACE-2, TMPRSS2 and S protein were insignificant. Further, FA-treated mammalian cells showed significant overexpression of ACE-2, NRP-1 and TMPRSS2 genes except with L-lactic acid and oleic acid caused downregulation of NRP-1 gene, while 17-octadecynoic acid caused insignificant effect. CONCLUSION: Collectively, a healthy oral cavity is more susceptible to viral infection when compared to that complicated with periapical lesions. FAs play important role in viral infection and their balance can affect the viral loads. Shifting the balance towards higher levels of palmitic, stearic and 1-nonadecene caused significant upregulation of the aforementioned genes and hence higher viral loads. On the other hand, there is a reverse correlation between inflammation and expression of SARS-CoV-2 receptors. Therefore, a mouth preparation that can reduce the levels of palmitic, stearic and 1-nonadecene, while maintaining an immunomodulatory effect can be employed as a future protection strategy against viral infection.

Design, synthesis, and computational validation of novel compounds selectively targeting HER2-expressing breast cancer.

Human epidermal growth factor receptor (HER) is a family of multidomain proteins that plays important role in the regulation of several biological functions. HER2 is a member of HER that is highly presented in breast cancer cells. Here, we designed and synthesized a series of diaryl urea/thiourea compounds. The compounds were tested on HER2+ breast cancer cells including MCF-7 and SkBr3, compared to HER2- breast cancer cells including MDA-MB-231 and BT-549. Only compounds 12-14 at 10 µM showed selective anti-proliferative activity against MCF-7 and SkBr3 by 65-79%. Compounds 12-14 showed >80% inhibition of the intracellular kinase domain of HER2. The results obtained indicated that compounds 12-14 are selectively targeting HER2+ cells. The IC50 of compound 13 against MCF-7 and SkBR3 were 1.3 ± 0.009 and 0.73 ± 0.03 µM, respectively. Molecular docking and MD simulations (50 ns) were carried out, and their binding free energies were calculated. Compounds 12-14 formed strong hydrogen bond and pi-pi stacking interactions with the key residues Thr862 and Phe864. 3DQSAR model confirmed the role of 3-bromo substituent of pyridine ring and 4-chloro substituent of phenyl ring in the activity of the compounds. In conclusion, novel compounds, particularly 13 were developed selectively against HER2-expressing/overexpressing breast cancer cells including MCF7 and SkBr3.

Design, Synthesis and Evaluation of New Bioactive Oxadiazole Derivatives as Anticancer Agents Targeting Bcl-2.

A series of 2-(1H-indol-3-yl)-5-substituted-1,3,4-oxadiazoles, 4a-m, were designed, synthesized and tested in vitro as potential pro-apoptotic Bcl-2 inhibitory anticancer agents based on our previously reported hit compounds. Synthesis of the target 1,3,4-oxadiazoles was readily accomplished through a cyclization reaction of indole carboxylic acid hydrazide 2 with substituted carboxylic acid derivatives 3a-m in the presence of phosphorus oxychloride. New compounds 4a-m showed a range of IC50 values concentrated in the low micromolar range selectively in Bcl-2 positive human cancer cell lines. The most potent candidate 4-trifluoromethyl substituted analogue 4j showed selective IC50 values of 0.52-0.88 µM against Bcl-2 expressing cell lines with no inhibitory effects in the Bcl-2 negative cell line. Moreover, 4j showed binding that was two-fold more potent than the positive control gossypol in the Bcl-2 ELISA binding affinity assay. Molecular modeling studies helped to further rationalize anti-apoptotic Bcl-2 binding and identified compound 4j as a candidate with drug-like properties for further investigation as a selective Bcl-2 inhibitory anticancer agent.

Essential Oil-Based Design and Development of Novel Anti-Candida Azoles Formulation.

Candida is the most common fungal class, causing both superficial and invasive diseases in humans. Although Candida albicans is the most common cause of fungal infections in humans, C. auris is a new emergent serious pathogen causing complications similar to those of C. albicans. Both C. albicans and C. auris are associated with high mortality rates, mainly because of their multidrug-resistance patterns against most available antifungal drugs. Although several compounds were designed against C. albicans, very few or none were tested on C. auris. Therefore, it is urgent to develop novel effective antifungal drugs that can accommodate not only C. albicans, but also other Candida spp., particularly newly emergent one, including C. auris. Inspired by the significant broad-spectrum antifungal activities of the essential oil cuminaldehyde and the reported wide incorporation of azoles in the antifungal drugs, a series of compounds (UoST1-11) was designed and developed. The new compounds were designed to overcome the toxicity of the aldehyde group of cuminaldehyde and benefit from the antifungal selectivity of azoles. The new developed UoST compounds showed significant anti-Candida activities against both Candida species. The best candidate compound, UoST5, was further formulated into polymeric nanoparticles (NPs). The new formula, UoST5-NPs, showed similar activities to the nanoparticles-free drug, while providing only 25% release after 24 h, maintainng prolonged activity up to 48 h and affording no toxicity. In conclusion, new azole formulations with significantly enhanced activities against C. albicans and C. auris, while maintaining prolonged action and no toxicities at lower concentrations, were developed.

New Quinoline-Based Heterocycles as Anticancer Agents Targeting Bcl-2.

The Bcl-2 protein has been studied as an anticancer drug target in recent years, due to its gatekeeper role in resisting programmed cancer cell death (apoptosis), and the design of BH3 domain mimetics has led to the clinical approval of Venetoclax (ABT-199) for the treatment of chronic lymphocytic leukaemia. In this work we extend our previous studies on the discovery of indole-based heterocycles as Bcl-2 inhibitors, to the identification of quinolin-4-yl based oxadiazole and triazole analogues. Target compounds were readily synthesized via a common aryl-substituted quinolin-4-carbonyl-N-arylhydrazine-1-carbothioamide (5a-b) intermediate, through simple variation of the basic cyclisation conditions. Some of the quinoline-based oxadiazole analogues (e.g. compound 6i) were found to exhibit sub-micromolar anti-proliferative activity in Bcl-2-expressing cancer cell lines, and sub-micromolar IC50 activity within a Bcl2-Bim peptide ELISA assay. The Bcl-2 targeted anticancer activity of 6i was further rationalised via computational molecular modelling, offering possibilities to extend this work into the design of further potent and selective Bcl-2 inhibitory heteroaromatics with therapeutic potential.

Synthesis and evaluation of 5-(1H-indol-3-yl)-N-aryl-1,3,4-oxadiazol-2-amines as Bcl-2 inhibitory anticancer agents.

A series of 5-(1H-indol-3-yl)-N-aryl-1,3,4-oxadiazol-2-amines 8a-j has been designed, synthesized and tested in vitro as potential pro-apoptotic Bcl-2-inhibitory anticancer agents based on our previous lead compound 8a. Synthesis of the target compounds was readily accomplished through a cyclisation reaction between indole-3-carboxylic acid hydrazide (5) and substituted isothiocyanates 6a-j, followed by oxidative cyclodesulfurization of the corresponding thiosemicarbazide 7a-j using 1,3-dibromo-5,5-dimethylhydantoin. Active compounds of the series 8a-j were found to have sub-micromolar IC50 values selectively in Bcl-2 expressing human cancer cell lines; notably the 2-nitrophenyl analogue 8a was found to exhibit potent activity, and compounds 8a and 8e possessed comparable Bcl-2 binding affinity (ELISA assay) to the established natural product-based Bcl-2 inhibitor, gossypol. Molecular modeling studies helped to further rationalise anti-apoptotic Bcl-2 binding, and identified compounds 8a and 8e as candidates for further development as Bcl-2 inhibitory anticancer agents.

Azole-based compounds as potential anti-Acanthamoeba agents.

Acanthamoeba castellanii is an opportunistic pathogen with public health implications, largely due to its invasive nature and non-specific symptoms. Our study focuses on the potential of azole compounds, particularly those with triazole scaffolds, as anti-amoebic agents. Out of 10 compounds, compounds T1 and T8 exhibited effective anti-Acanthamoeba activity with MIC50 values of 125.37 and 143.92 µg mL-1, respectively. Interestingly, compounds T1, T4, T5 and T8 revealed profound anti-excystation activity with MIC50 at 32.01, 85.53, 19.54 and 80.57 µg mL-1, respectively, alongside limited cytotoxicity to human cells. The study underscores the potential of T1, T4, T5, and T8, thiazole-based compounds, as anti-Acanthamoeba agents by both eliminating amoeba viability and preventing excystation, via preserving the amoeba in its latent cyst form, exposing them to elimination by the immune system. Notably, compounds T1, T4, T5, and T8 showed optimal molecular properties, moderate oral bioavailability, and stable complex formation with Acanthamoeba CYP51. They also display superior binding interactions. Further research is needed to understand their mechanisms and optimize their efficacy against Acanthamoeba infections.

Structure-based drug design of DNA minor groove binders and evaluation of their antibacterial and anticancer properties.

Antimicrobial and chemotherapy resistance are escalating medical problem of paramount importance. Yet, research for novel antimicrobial and anticancer agents remains lagging behind. With their reported medical applications, DNA minor groove binders (MGBs) are worthy of exploration. In this study, the approach of structure-based drug design was implemented to generate 11 MGB compounds including a novel class of bioactive alkyne-linked MGBs. The NCI screening protocol was utilized to evaluate the antitumor activity of the target MGBs. Furthermore, a variety of bactericidal, cytopathogenicity, MIC90, and cytotoxicity assays were carried out using these MGBs against 6 medically relevant bacteria: Salmonella enterica, Escherichia coli, Serratia marcescens, Bacillus cereus, Streptococcus pneumoniae and Streptococcus pyogenes. Moreover, molecular docking, molecular dynamic simulations, DNA melting, and isothermal titration calorimetry (ITC) analyses were utilized to explore the binding mode and interactions between the most potent MGBs and the DNA duplex d(CGACTAGTCG)2. NCI results showed that alkyne-linked MGBs (26 & 28) displayed the most significant growth inhibition among the NCI-60 panel. In addition, compounds MGB3, MGB4, MGB28, and MGB32 showed significant bactericidal effects, inhibited B. cereus and S. enterica-mediated cytopathogenicity, and exhibited low cytotoxicity. MGB28 and MGB32 demonstrated significant inhibition of S. pyogenes, whereas MGB28 notably inhibited S. marcescens and all four minor groove binders significantly inhibited B. cereus. The ability of these compounds to bind with DNA and distort its groove dimensions provides the molecular basis for the allosteric perturbation of proteins-DNA interactions by MGBs. This study shed light on the mechanism of action of MGBs and revealed the important structural features for their antitumor and antibacterial activities, which are important to guide future development of MGB derivatives as novel antibacterial and anticancer agents.

Uniqueness of Candida auris cell wall in morphogenesis, virulence, resistance, and immune evasion.

Candida auris has drawn global attention due to its alarming multidrug resistance and the emergence of pan resistant strains. C. auris poses a significant risk in nosocomial candidemia especially among immunocompromised patients. C. auris showed unique virulence characteristics associated with cell wall including cell polymorphism, adaptation, endurance on inanimate surfaces, tolerance to external conditions, and immune evasion. Notably, it possesses a distinctive cell wall composition, with an outer mannan layer shielding the inner 1,3-ß glucan from immune recognition, thereby enabling immune evasion and drug resistance. This review aimed to comprehend the association between unique characteristics of C. auris's cell wall and virulence, resistance mechanisms, and immune evasion. This is particularly relevant since the fungal cell wall has no human homology, providing a potential therapeutic target. Understanding the complex interactions between the cell wall and the host immune system is essential for devising effective treatment strategies, such as the use of repurposed medications, novel therapeutic agents, and immunotherapy like monoclonal antibodies. This therapeutic targeting strategy of C. auris holds promise for effective eradication of this resilient pathogen.

1H-NMR metabolomics analysis identifies hypoxanthine as a novel metastasis-associated metabolite in breast cancer.

Breast cancer is one of the leading causes of death in females, mainly because of metastasis. Oncometabolites, produced via metabolic reprogramming, can influence metastatic signaling cascades. Accordingly, and based on our previous results, we propose that metabolites from highly metastatic breast cancer cells behave differently from less-metastatic cells and may play a significant role in metastasis. For instance, we aim to identify these metabolites and their role in breast cancer metastasis. Less metastatic cells (MCF-7) were treated with metabolites secreted from highly metastatic cells (MDA-MB-231) and the gene expression of three epithelial-to-mesenchymal transition (EMT) markers including E-cadherin, N-cadherin and vimentin were examined. Some metabolites secreted from MDA-MB-231 cells significantly induced EMT activity. Specifically, hypoxanthine demonstrated a significant EMT effect and increased the migration and invasion effects of MCF-7 cells through a hypoxia-associated mechanism. Hypoxanthine exhibited pro-angiogenic effects via increasing the VEGF and PDGF gene expression and affected lipid metabolism by increasing the gene expression of PCSK-9. Notably, knockdown of purine nucleoside phosphorylase, a gene encoding for an important enzyme in the biosynthesis of hypoxanthine, and inhibition of hypoxanthine uptake caused a significant decrease in hypoxanthine-associated EMT effects. Collectively for the first time, hypoxanthine was identified as a novel metastasis-associated metabolite in breast cancer cells and represents a promising target for diagnosis and therapy.