Half Maximal Inhibitory Concentration Research Articles

Leucinostatins from fungal extracts block malaria transmission to mosquitoes

BackgroundMalaria is a mosquito-transmitted disease that kills more than half a million people annually. The lack of effective malaria vaccines and recently increasing malaria cases urge innovative approaches to prevent malaria. Previously, we reported that the extract from the soil-dwelling fungus Purpureocillium lilacinum, a common fungus from the soil, reduced Plasmodium falciparum oocysts in Anopheles gambiae midguts after mosquitoes contacted the treated surface before feeding.MethodsWe used liquid chromatography to fraction fungal crude extract and tract the active fraction using a contact-wise approach and standard membrane feeding assays. The purified small molecules were analyzed using precise mass spectrometry and tandem mass spectrometry.ResultsWe isolated four active small molecules from P. lilacinum and determined them as leucinostatin A, B, A2, and B2. Pre-exposure of mosquitoes via contact with very low-concentration leucinostatin A significantly reduced the number of oocysts. The half-maximal response or inhibition concentration (EC50) via pre-exposure was 0.7 mg/m2, similar to atovaquone but lower than other known antimalarials. The inhibitory effect of leucinostatin A against P. falciparum during intraerythrocytic development, gametogenesis, sporogonic development, and ookinete formation, with the exception of oocyst development, suggests that leucinostatins play a part during parasite invasion of new cells.ConclusionsLeucinostatins, secondary metabolites from P. lilacinum disrupt malaria development, particular transmission to mosquitoes by contact. The contact-wise malaria control as a nonconventional approach is highly needed in malaria-endemic areas.Graphical

Candidate-Probiotic Lactobacilli and Their Postbiotics as Health-Benefit Promoters

Lactobacillus species are widely recognized for their probiotic potential, focusing on their mechanisms of health benefits and protection. Here we conducted an in vitro investigation of the probiotic potential with a role in microbiome homeostasis of four strains: Lactiplantibacillus plantarum L6 and F53, Ligilactobacillus salivarius 1, and Lactobacillus helveticus 611. A broad spectrum of antibacterial and antifungal activity was determined. The strain-specific inhibition of Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and saprophytic/toxigenic fungi makes them promising as protective cultures. DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) measurements showed that tested samples had strain-specific capacity for scavenging of radicals. The molecular base for the antioxidant potential of two lyophilized forms of active strains was investigated by electron paramagnetic resonance spectroscopy. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, with fractions of the most active postbiotics obtained by SEC-FPLC (fast protein liquid chromatography) analysis, showed a wide variety of effects on the growth of a K562 myeloid leukemia cell line. The IC50 (half-maximal inhibitory concentration) of L. salivarius 1 was determined to be 46.15 mg/mL. The proven in vitro functionality of the selected lactobacilli make them suitable for development of target probiotics with specific beneficial effects expected in vivo. Further investigations on produced postbiotics and safety have to be completed before they can be considered as scientifically proven probiotic strains.

Developing a novel calcium silver zeolite for caries management

ObjectiveTo develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects.MethodsCa-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay.ResultsCa-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively.ConclusionA novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms.

Determination of 3-Phenoxybenzoic Acid by an Improved Enzyme-Linked Immunosorbent Assay (ELISA) by the Immobilization of Nanobodies with Streptavidin and Biotin

Nanobodies (Nbs) are single domain antibodies that are frequently utilized in enzyme-linked immunosorbent assays (ELISAs). However, a major limitation of nanobodies is their low sensitivity in capture assays. To address this issue, the combination of streptavidin and biotin can be employed to immobilize the nanobodies on plates in an oriented manner, thereby exposing their binding sites. In this study, nanobodies specific to 3-phenoxybenzoic acid (3-PBA) were biotinylated at their C-termini and immobilized onto streptavidin-coated microplates. A direct competitive ELISA was developed for the determination of 3-phenoxybenzoic acid in ovine and bovine urine. Compared to directly coating the nanobodies, the streptavidin-bridged nanobody capture-based ELISA demonstrated improved sensitivity, with a 16.6% enhancement, and a half-maximum inhibition concentration (IC50) of 2.05 ng/mL. The developed assay provided a linear range from 0.27 to 20.2 ng/mL (IC20-IC80) and a limit of detection (LOD) of 0.1 ng/mL. The average recoveries of 3-phenoxybenzoic acid spiked in the urine ranged from 82.57% to 102.75% and were consistent with values obtained by liquid chromatography – mass spectrometry (LC-MS). These findings demonstrate that the streptavidin-bridged capture nanobody-based ELISA significantly enhanced the sensitivity for the determination of 3-phenoxybenzoic acid residues in animal urine.

Pluronic F127-Complexed PEGylated Poly(glutamic acid)-Cisplatin Nanomedicine for Enhanced Glioblastoma Therapy.

Glioblastoma is one of the most aggressive and treatment-resistant forms of primary brain cancer, posing significant challenges in effective therapy. This study aimed to enhance the effectiveness of glioblastoma therapy by developing a unique nanomedicine composed of Pluronic F127-complexed PEGylated poly(glutamic acid)-cisplatin (PLG-PEG/PF127-CDDP). PLG-PEG/PF127-CDDP demonstrated an optimal size of 133.97±12.60nm, facilitating efficient cell uptake by GL261 glioma cells. In vitro studies showed significant cytotoxicity against glioma cells with a half-maximal (50%) inhibitory concentration (IC50) of 12.61µgmL-1 at 48h and a 72.53%±1.89% reduction in cell invasion. Furthermore, PLG-PEG/PF127-CDDP prolonged the circulation half-life of cisplatin to 9.75h in vivo, leading to a more than 50% reduction in tumor size on day 16 post-treatment initiation in a murine model of glioma. The treatment significantly elevated lactate levels in GL261 cells, indicating enhanced metabolic disruption. Therefore, PLG-PEG/PF127-CDDP offers a promising approach for glioblastoma therapy due to its effects on improving drug delivery efficiency, therapeutic outcomes, and safety while minimizing systemic side effects. This work underscores the potential of polymer-based nanomedicines in overcoming the challenges of treating brain tumors, paving the way for future clinical applications.

Inhibitory Effects of Royal Jelly and Its Functional Components on the Proliferation of MKN-28 Gastric Cancer Cells.

Royal jelly (RJ) is a natural food product with nutritional value and anticancer activity. However, their effects on gastric cancer are unclear. Here, we show that treatment with 5-320 μg/mL of RJ, ethanol extract (RJEE), and protein hydrolyzate (RJPH) decreased the viability of MKN-28 gastric cancer cells, with a half-maximal inhibitory concentration of 123.22 μg/mL for RJEE. RJ, RJEE, and RJPH increase the lactate dehydrogenase release rate and change the morphology of the cells, resulting in cell shrinkage, nucleoplasm condensation, and the formation of apoptotic bodies. RJ and its functional components stagnated the cell cycle in the G0/G1 phase, accompanied by the accumulation of reactive oxygen species, decreased mitochondrial membrane potential, and increased expression levels of p53 and p21 proteins, caspase-3 activation, and apoptosis. Therefore, RJ, RJEE, and RJPH have potential inhibitory effects on the proliferation of gastric cancer cells.

Effect of isavuconazole on the pharmacokinetics of sunitinib and its mechanism

BackgroundSunitinib, a newly developed multi-targeted tyrosine kinase inhibitor (TKI), has become a common therapeutic option for managing advanced renal cell carcinoma (RCC). Examining the mechanism underlying the interaction between sunitinib and isavuconazole was the aim of this effort.MethodsThe concentrations of sunitinib and its primary metabolite, N-desethyl sunitinib, were analyzed and quantified using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Our study evaluated the potential interaction between isavuconazole and sunitinib using rat liver microsomes (RLM), human liver microsomes (HLM), and in vivo rat models. For the in vivo study, two groups (n = 5) of Sprague-Dawley (SD) rats were randomly allocated to receive sunitinib either with or without co-administration of isavuconazole. Additionally, the effects of isavuconazole on the metabolic stability of sunitinib and N-desethyl sunitinib were studied in RLM in vitro.ResultsOur findings demonstrated that in RLM, isavuconazole exhibited a mixed non-competitive and competitive inhibition mechanism, with an IC50 (half maximal inhibitory concentration) value of 1.33 µM. Meanwhile, in HLM, isavuconazole demonstrated a competitive inhibition mechanism, with an IC50 of 5.30 µM. In vivo studies showed that the presence of isavuconazole significantly increased the pharmacokinetic characteristics of sunitinib, with the AUC(0→t), AUC(0→∞), and Tmax rising to approximately 211.38%, 203.92%, and 288.89%, respectively, in contrast to the control group (5 mg/kg sunitinib alone). The pharmacokinetic characteristics of the metabolite N-desethyl sunitinib in the presence of isavuconazole remained largely unchanged compared to the control group. Furthermore, in vitro metabolic stability experiments revealed that isavuconazole inhibited the metabolic processing of both sunitinib and N-desethyl sunitinib.ConclusionsIsavuconazole had a major impact on sunitinib metabolism, providing fundamental information for the precise therapeutic administration of sunitinib.

Preparation of monoclonal antibody against rhoifolin and its application in enzyme-linked immunosorbent assay of rhoifolin and diosmin

Both rhoifolin and diosmin belong to flavonoids, which are widely present in citrus. Diosmin is not only used in the medical field in the world, but also used as a dietary supplement in the United States. Rhoifolin has a similar structure to diosmin and also exhibits antioxidant and anti-inflammatory properties. In this study, an anti-rhoifolin monoclonal antibody was prepared and an indirect competitive enzyme-linked immunosorbent assay (icELISA) method was established. The half-maximal inhibitory concentration (IC50) of icELISA was determined to be 4.83 ng/mL, and the detection range was 0.97–33.87 ng/mL. The results of UPLC-MS/MS and icELISA generally demonstrate consistency. Moreover, by exploiting the cross-reactivity of the antibody, diosmin in tablets can be detected by icELISA. The results demonstrate that the developed method has good accuracy, reproducibility, and broad application prospects.

Evaluation of cytotoxic potential of silver nanoparticles biosynthesized using essential oils of Jasminum sambac against breast cancer and bacterial cells.

Essential oils (EOs) which cover about 91% whole biomolecules formulated from Jasminum sambac leaves based on Gas chromatography-mass spectrometry were employed to identify structures. EOs were observed as good agents in the preparation of Silver nanoparticles (AgNPs) through the proposed mechanism that was attempted to interpret the pathway of the bio-preparation process. The characterization of EOs-AgNPs carried via ultraviolet-visible to reveal surface plasmon resonance at 420nm, Fourier transform infrared to observe functional groups EOs compared to EOs-AgNPs. X-ray diffraction (XRD) revealed a broad chart owing to the small size of AgNPs in average size less than 10nm calculated relying on image J software, spherical AgNPs with a small dispersive size observed by transmission electron microscopy. Quasi near spherical surface morphology of EOs-AgNPs had detected by field emission scanning electron microscope. EOs-AgNPs were assessed for their antibacterial potential against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria as suppressing bacterial agents. EOs-AgNPs had their anti-breast cancer MCF-7 cell line ability investigated by DNA fragmentation; cycle flow cytometry (apoptosis) at half maximal inhibitory concentration (IC50) was determined at 260µg/mL which has been stated by cytotoxicity (MTT) assay. EOs-AgNPs have antibacterial and anticancer therapeutic potential, and it is safe, inexpensive, and scalable in the nanoscale range.

Cytotoxic properties, glycolytic effects and high-resolution respirometry mitochondrial activities of Eriocephalus racemosus against MDA-MB 231 triple-negative breast cancer

IntroductionTriple-negative breast cancer (TNBC) represents a significant global health crisis due to its resistance to conventional therapies and lack of specific molecular targets. This study explored the potential of Eriocephalus racemosus (E. racemosus) as an alternative treatment for TNBC. The cytotoxic properties and high-resolution respirometry mitochondrial activities of E. racemosus against the MDA-MB 231 TNBC cell line were evaluated.MethodsHexane solvent and bioactive fraction extractions of E. racemosus were performed, while mass spectrometry-based metabolite profiling was used to identify the phytochemical constituents of the extracts. The extracts were further tested against MDA-MB 231 TNBC cells to determine their cytotoxicity. The mode of cell death was determined using flow cytometry. The activities of caspases 3, 8, and 9 were assessed using a multiplex activity assay kit. Glycolytic activity and High-resolution respirometry measurements of mitochondrial function in the MDA-MB 231 cell line were conducted using the Seahorse XFp and Oroboros O2K.ResultsMetabolite profiling of E. racemosus plant crude extracts identified the presence of coumarins, flavonoids, sesquiterpenoids, triterpenoids, and unknown compounds. The extracts demonstrated promising cytotoxic activities, with a half maximal inhibitory concentration (IC50) of 12.84 µg/mL for the crude hexane extract and 15.49 µg/mL for the bioactive fraction. Further, the crude hexane and bioactive fraction extracts induced apoptosis in the MDA-MB-231 TNBC cells, like the reference drug cisplatin (17.44%, 17.26% and 20.25%, respectively) compared to untreated cells. Caspase 3 activities confirmed the induction of apoptosis in both cisplatin and the plant crude extracts, while caspase 8 and 9 activities confirmed the activation of both the intrinsic and extrinsic apoptosis pathways. Increased levels of glycolytic activity were observed in the hexane crude extract. High-resolution respiratory measurements showed elevated mitochondrial activities in all mitochondrial states except for complex-IV activity.ConclusionThese findings support further exploration of E. racemosus as a potential therapeutic agent for TNBC, offering a promising avenue for the development of targeted treatments with minimal adverse effects.

Effects of HyaRegen gel on tumour proliferation of colorectal peritoneal metastases.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a valuable therapeutic alternative for patients with peritoneal metastases. PIPAC uses a hyaluronic acid-based gel to reduce surgically induced adhesions. The aim of this study was to evaluate the effects of the hyaluronic acid-based gel on tumor dissemination. First, we explored whether the survival of CT26 luciferase-expressing murine colonic tumor cells was correlated with the dose of HyaRegen® Gel, and we determined the half-maximal inhibitory concentration (the IC50) of the gel. Next, we performed an in vitro study of cell survival rates after gel application on day 0 (D0) and day 1 (D1). Finally, we intraperitoneally administered the gel to mice with immunocompetent BALB/c colonic peritoneal metastases (on D0, D5, D10, D14, and D18). Tumor growth was regularly monitored using a bioluminescence assay (on D11, D17, and D21). After all mice had been sacrificed on D21, the body weights and the volumes of intraperitoneal ascites were measured; the Peritoneal Carcinosis Index (PCI) and Ki-antigen 67 scores were calculated. The IC50 value was 70 μL of gel in a total volume of 100 μL. The cell survival rates on D4 were identical in the control group and the two groups that had been treated with gel on D0 and D1. The bioluminescence levels over time were similar in the gel and control groups. The PCI scores were 35.5 ± 2.89 for the control group and 36 ± 2.45 for the gel group (p = 0.8005). The mean Ki-67 index percentages were 37.28 ±1 1.75 for the control group and 34.03 ± 8.62 for the gel group (p = 0.1971). This in vitro and in vivo study using a mouse model of immunocompetent metastatic peritoneal cancer did not reveal any pro- or anti-tumoral effect of HyaRegen® Gel. These findings indicate that the gel can be used to treat PIPACs with minimal apprehension.

High Photocytotoxicity Iridium(III) Complex Photosensitizer for Photodynamic Therapy Induces Antitumor Effect Through GPX4-Dependent Ferroptosis.

The development of small molecule photosensitizers based on iridium complex is limited by the mismatch between therapeutic effect and systemic toxicity, as well as the incomplete understanding of the molecular mechanism underlying cell death induction. Herein, a small molecule iridium complex IrC with high photocytotoxicity is synthesized, with half maximal inhibitory concentration as low as 91 nm, demonstrating excellent anti-tumor, relief of splenomegaly, and negligible side effects. Starting from the factors of effective photosensitizers, the in-depth theoretical analysis on photon absorption efficiency, energy transfer level matching, and properties of the triplet excited state of IrC is conducted. This also elucidates the feasibility of generating the high singlet oxygen quantum yield. In addition, the death mechanism induced by IrC is focused, innovatively utilizing GPX4-overexpression and GPX4-knockout cells via CRISPR/Cas9 technique to comprehensively verify ferroptosis and its further molecular mechanism. The generation of ROS mediated by IrC, along with the direct inhibition of GPX4 and glutathione, synergistically increased cellular oxidative stress and the level of lipid peroxidation. This study provides an effective approach for small molecule complexes to induce GPX4-dependent ferroptosis at low-dose photodynamic therapy.

Engineered Liver-derived Decellularized Extracellular Matrix-based Three-Dimensional Tumor Constructs for Enhanced Drug Screening Efficiency

Abstract The decellularized extracellular matrix (dECM) has emerged as an effective medium for replicating the in vivo-like conditions of the tumor microenvironment (TME), thus enhancing the screening accuracy of chemotherapeutic agents. However, recent dECM-based tumor models have exhibited challenges such as uncontrollable morphology and diminished cell viability, hindering the precise evaluation of chemotherapeutic efficacy. Herein, we utilized a tailor-made microfluidic approach to encapsulate dECM from porcine liver in highly poly(lactic-co-glycolic acid) (PLGA) porous microspheres (dECM-PLGA PMs) to engineer a three-dimensional (3D) tumor model. These dECM-PLGA PMs-based microtumors exhibited significant promotion of hepatoma carcinoma cells (HepG2) proliferation compared to PLGA PMs alone, since the infusion of extracellular matrix (ECM) microfibers and biomolecular constituents within the PMs. Proteomic analysis of the dECM further revealed the potential effects of these bioactive fragments embedded in the PMs. Notably, dECM-PLGA PMs-based microtissues effectively replicated the drug resistance traits of tumors, showing pronounced disparities in half-maximal inhibitory concentration (IC50) values, which could correspond with certain aspects of the TME. Collectively, these dECM-PLGA PMs substantially surmounted the prevalent challenges of unregulated microstructure and suboptimal cell viability in conventional 3D tumor models. They also offer a sustainable and scalable platform for drug testing, holding promise for future pharmaceutical evaluations.

AI-Based Discovery and CryoEM Structural Elucidation of a KATP Channel Pharmacochaperone.

Pancreatic KATP channel trafficking defects underlie congenital hyperinsulinism (CHI) cases unresponsive to the KATP channel opener diazoxide, the mainstay medical therapy for CHI. Current clinically used KATP channel inhibitors have been shown to act as pharmacochaperones and restore surface expression of trafficking mutants; however, their therapeutic utility for KATP trafficking impaired CHI is hindered by high-affinity binding, which limits functional recovery of rescued channels. Recent structural studies of KATP channels employing cryo-electron microscopy (cryoEM) have revealed a promiscuous pocket where several known KATP pharmacochaperones bind. The structural knowledge provides a framework for discovering KATP channel pharmacochaperones with desired reversible inhibitory effects to permit functional recovery of rescued channels. Using an AI-based virtual screening technology AtomNet® followed by functional validation, we identified a novel compound, termed Aekatperone, which exhibits chaperoning effects on KATP channel trafficking mutations. Aekatperone reversibly inhibits KATP channel activity with a half-maximal inhibitory concentration (IC50) ~ 9 μM. Mutant channels rescued to the cell surface by Aekatperone showed functional recovery upon washout of the compound. CryoEM structure of KATP bound to Aekatperone revealed distinct binding features compared to known high affinity inhibitor pharmacochaperones. Our findings unveil a KATP pharmacochaperone enabling functional recovery of rescued channels as a promising therapeutic for CHI caused by KATP trafficking defects.

Design, synthesis, and in vitro and in silico study of 1-benzyl-indole hybrid thiosemicarbazones as competitive tyrosinase inhibitors.

Developing new anti-tyrosinase drugs seems crucial for the medical and industrial fields since irregular melanin synthesis is linked to the resurgence of several skin conditions, including melanoma, and the browning of fruits and vegetables. A novel series of N-1 and C-3 substituted indole-based thiosemicarbazones 5(a-r) are synthesized and further analyzed for their inhibition potential against tyrosinase enzyme through in vitro assays. The synthesized compounds displayed very good to moderate inhibition with half maximal inhibitory concentration in the range of 12.40 ± 0.26 μM to 47.24 ± 1.27 μM. Among all the derivatives 5k displayed the highest inhibitory activity. According to SAR analysis, the derivatives with 4-substitution at the benzyl or phenyl ring of the thiosemicarbazones exhibited better inhibitory potential against tyrosinase. In silico analysis (including ADMET prediction and molecular docking) was conducted and compared with the standard drug (kojic acid). These findings may help the hunt for new melanogenesis inhibitors that the food and cosmetics industries may find valuable.

Effect of Genistein on Starch Digestion In Vitro and Its Mechanism of Action.

The digestive properties of starch are crucial in determining postprandial glycaemic excursions. Genistein, an active phytoestrogen, has the potential to influence starch digestion rates. We investigated the way genistein affected the digestive properties of starch in vitro. We performed enzyme kinetics, fluorescence spectroscopy, molecular docking, and molecular dynamics (MD) simulations for analysing the inhibitory properties of genistein on starch digestive enzymes as well as clarifying relevant mechanism of action. Our findings demonstrated that, following the addition of 10% genistein, the contents of slowly digestible and resistant starches increased by 30.34% and 7.18%, respectively. Genistein inhibited α-amylase and α-glucosidase, with half maximal inhibitory concentrations of 0.69 ± 0.06 and 0.11 ± 0.04 mg/mL, respectively. Genistein exhibits a reversible and non-competitive inhibiting effect on α-amylase, while its inhibition on α-glucosidase is a reversible mixed manner type. Fluorescence spectroscopy indicated that the presence of genistein caused declining fluorescence intensity of the two digestive enzymes. Molecular docking and MD simulations showed that genistein binds spontaneously to α-amylase via hydrogen bonds, hydrophobic interactions, and π-stacking, whereas it binds with α-glucosidase via hydrogen bonds and hydrophobic interactions. These findings suggest the potential for developing genistein as a pharmacologic agent for regulating glycaemic excursions.

A general prediction model for compound-protein interactions based on deep learning.

The identification of compound-protein interactions (CPIs) is crucial for drug discovery and understanding mechanisms of action. Accurate CPI prediction can elucidate drug-target-disease interactions, aiding in the discovery of candidate compounds and effective synergistic drugs, particularly from traditional Chinese medicine (TCM). Existing in silico methods face challenges in prediction accuracy and generalization due to compound and target diversity and the lack of largescale interaction datasets and negative datasets for model learning. To address these issues, we developed a computational model for CPI prediction by integrating the constructed large-scale bioactivity benchmark dataset with a deep learning (DL) algorithm. To verify the accuracy of our CPI model, we applied it to predict the targets of compounds in TCM. An herb pair of Astragalus membranaceus and Hedyotis diffusaas was used as a model, and the active compounds in this herb pair were collected from various public databases and the literature. The complete targets of these active compounds were predicted by the CPI model, resulting in an expanded target dataset. This dataset was next used for the prediction of synergistic antitumor compound combinations. The predicted multi-compound combinations were subsequently examined through in vitro cellular experiments. Our CPI model demonstrated superior performance over other machine learning models, achieving an area under the Receiver Operating Characteristic curve (AUROC) of 0.98, an area under the precision-recall curve (AUPR) of 0.98, and an accuracy (ACC) of 93.31% on the test set. The model's generalization capability and applicability were further confirmed using external databases. Utilizing this model, we predicted the targets of compounds in the herb pair of Astragalus membranaceus and Hedyotis diffusaas, yielding an expanded target dataset. Then, we integrated this expanded target dataset to predict effective drug combinations using our drug synergy prediction model DeepMDS. Experimental assay on breast cancer cell line MDA-MB-231 proved the efficacy of the best predicted multi-compound combinations: Combination I (Epicatechin, Ursolic acid, Quercetin, Aesculetin and Astragaloside IV) exhibited a half-maximal inhibitory concentration (IC50) value of 19.41μM, and a combination index (CI) value of 0.682; and Combination II (Epicatechin, Ursolic acid, Quercetin, Vanillic acid and Astragaloside IV) displayed a IC50 value of 23.83μM and a CI value of 0.805. These results validated the ability of our model to make accurate predictions for novel CPI data outside the training dataset and evaluated the reliability of the predictions, showing good applicability potential in drug discovery and in the elucidation of the bioactive compounds in TCM. Our CPI prediction model can serve as a useful tool for accurately identifying potential CPI for a wide range of proteins, and is expected to facilitate drug research, repurposing and support the understanding of TCM.

Characterization and Antioxidant Activity of Eumelanin Produced by Streptomyces lasalocidi NTB 42

Melanin, a macromolecule derived from the oxidative polymerization of phenolic compounds, possesses notable bioactive attributes and serves as a crucial biological safeguard against deleterious environmental factors. Melanin originates in Streptomyces and is known for its antioxidative properties. This study aimed to characterize and evaluate the antioxidant activity of melanin obtained from Streptomyces lasalocidi NTB 42. Based on 16S rRNA identification, strain NTB 42 was identified as Streptomyces lasalocidi NTB 42 (OR710932). During melanin biosynthesis, S. lasalocidi NTB 42 had the highest tyrosinase activity on day 5 and the highest L-3,4-dihydroxyphenylalanine concentration on day 6. Melanin NTB 42 exhibited polymorphic and irregular morphology. Melanin NTB 42 characteristics were analyzed using the A650/A500 ratio, UV-visible spectroscopy, Fourier transform infrared spectroscopy, high-performance liquid chromatography, dispersive X-ray spectroscopy, and thermal degradation products based on pyrolysis-gas chromatography-mass spectrometry were identified as eumelanin. The scavenging ability of NTB 42 melanin, as determined by the half maximal inhibitory concentration (IC50), was 70.60±0.40 μg/mL for 2,2-diphenyl-1-picrylhydrazyl and 176.76±0.93 μg/mL for 2,2'-azino-bis(3-ethylbenzothiazolin-6-acid sulfonate radicals. The Fe-reducing power and total antioxidasssnt capacity values were 114.05±0.41 mg AAE/g melanin and 145.10±0.56 mg AAE/g melanin, respectively. This study is the first attempt to characterize the antioxidant properties of eumelanin from S. lasalocidi NTB 42. The antioxidant ability of eumelanin NTB 42 against various free radicals shows promise for further development as an antioxidant.

Lipophilic derivatives of EGCG as potent α-amylase and α-glucosidase inhibitors ameliorating oxidative stress and inflammation

Uncontrolled hyperglycemia leads to increased oxidative stress, chronic inflammation, and insulin resistance, rendering diabetes management harder to accomplish. To tackle these myriads of challenges, researchers strive to explore innovative multifaceted treatment strategies, including inhibiting carbohydrate hydrolases. Herein, we report alkyl-ether EGCG derivatives as potent α-amylase and α-glucosidase inhibitors that could simultaneously ameliorate oxidative stress and inflammation. 4″-C18 EGCG, the most promising compound, showed multifold improvement in glycaemic management compared to acarbose, with 230-fold greater inhibition (competitive) of α-glucosidase (half-maximal inhibitory concentration (IC50) 0.81 µM) and 3-fold better inhibition of α-amylase (IC50 3.74 µM). All derivatives showed stronger antioxidant activity (IC50 6.16–15.76 µM) than vitamin C, while acarbose showed none. 4″-C18 EGCG also downregulated pro-inflammatory cytokines and showed no significant cytotoxicity up to 50 µM in primary human peripheral blood mononuclear cells (PBMC), non-cancerous cell line, 3T3-L1 and HEK 293. The in silico binding affinity analysis of 4″-C18 EGCG with α-amylase and α-glucosidase was found to exhibit a good extent of interaction as compared to acarbose. In comparison to EGCG, the high molecular mass compound was found to remain stable in the physiological conditions even after 24 h. Together, the reported molecules demonstrated multifaceted antidiabetic potential inhibiting carbohydrate hydrolases, reducing oxidative stress, and inflammation, which are known to aggravate diabetes.

Shiitake mushroom-derived extracellular nanovesicles: Preparation, characterization, and inhibition of Caco-2 cells

In this study, Shiitake mushroom-derived extracellular nanovesicles (SMDENVs) were isolated from fresh Shiitake mushrooms by ultracentrifugation and sucrose gradient ultracentrifugation. The morphological characteristics of SMDENVs were investigated via Transmission Electron Microscopy and Laser Scanning Confocal Microscopy. SMDENVs were spherical, hollow, and uniform in size, with an average diameter of 177.6 ± 51.4 nm. Based on the analysis of lipidomics and proteomics, 383 lipids species and 1290 proteins were identified in SMDENVs. Compared with the conventional liposomes, SMDENVs demonstrated higher stability in different environmental conditions. Furthermore, we observed that SMDENVs were cytocompatible and inhibited the proliferation of Caco-2 cells. SMDENVs could be phagocytized by Caco-2 cells in a time-dependent manner. Further, SMDENVs also inhibited the proliferation of Caco-2 cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC50) was 236.2 ± 3.2 μg/mL. Additionally, SMDENVs induced cellular apoptosis by increasing the levels of reactive oxygen species and decreasing the mitochondrial membrane potential.