Strong Activity Research Articles

Mycophenolate mofetil inhibits Merkel cell carcinoma growth.

The direct antitumour effects of mTOR inhibitors against cutaneous squamous cell carcinoma (SCC) have prompted a paradigm shift towards using sirolimus for allograft rejection prophylaxis in patients with high-risk SCC who have had a solid organ transplant (SOT). Patients who have had an SOT are at higher risk for Merkel cell carcinoma (MCC), yet there is little evidence concerning potential antitumour effects of immunosuppressive drugs against MCC. Screening seven immunosuppressive drugs in six MCC cell lines revealed that mycophenolate mofetil (MMF) had strong antitumour activity (surpassing mTOR inhibitors) and higher potency in MCC vs. other cancer types. MMF also inhibited MCC tumour growth in mice. Our preclinical findings strongly suggest the utility of MMF in patients with MCC who require immunosuppression.

Plant U-box E3 ligases PUB20 and PUB21 negatively regulate pattern-triggered immunity in Arabidopsis.

Plant U-box E3 ligases PUB20 and PUB21 are flg22-triggered signaling components and negatively regulate immune responses. Plant U-box proteins (PUBs) constitute a class of E3 ligases that are associated with various stress responses. Among the class IV PUBs featuring C-terminal Armadillo (ARM) repeats, PUB20 and PUB21 are closely related homologs. Here, we show that both PUB20 and PUB21 negatively regulate innate immunity in plants. Loss of PUB20 and PUB21 function leads to enhanced resistance to surface inoculation with the virulent bacterium Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). However, the resistance levels remain unaffected after infiltration inoculation, suggesting that PUB20 and PUB21 primarily function during the early defense stages. The enhanced resistance to Pst DC3000 in PUB mutant plants (pub20-1, pub21-1, and pub20-1/pub21-1) correlates with extensive flg22-triggered reactive oxygen production, strong MPK3 activation, and enhanced transcriptional activation of early immune response genes. Additionally, PUB mutant plants (except pub21-1) exhibit constitutive stomatal closure after Pst DC3000 inoculation, implying the significant role of PUB20 in stomatal immunity. Comparative analyses of flg22 responses between PUB mutants and wild-type plants reveals that the robust activation of the pattern-induced immune responses may enhance resistance against Pst DC3000. Notably, the hypersensitivity responses triggered by RPM1/avrRpm1 and RPS2/avrRpt2 are independent of PUB20 and PUB21. These results suggest that PUB20 and PUB21 knockout mutations affect bacterial invasion, likely during the early stages, acting as negative regulators of plant immunity.

Coassembled Multicomponent Protein Nanoparticles Elicit Enhanced Antibacterial Activity.

The waning pipeline of the useful antibacterial arsenal has necessitated the urgent development of more effective antibacterial strategies with distinct mechanisms to rival the continuing emergence of resistant pathogens, particularly Gram-negative bacteria, due to their explicit drug-impermeable, two-membrane-sandwiched cell wall envelope. Herein, we have developed multicomponent coassembled nanoparticles with strong bactericidal activity and simultaneous bacterial cell envelope targeting using a peptide coassembly strategy. Compared to the single-component self-assembled nanoparticle counterparts or cocktail mixtures of these at a similar concentration, coassembled multicomponent nanoparticles showed higher bacterial killing efficiency against Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli by several orders of magnitude (about 100-1,000,000-fold increase). Comprehensive confocal and electron microscopy suggest that the superior antibacterial activity of the coassembled nanoparticles proceeds via multiple complementary mechanisms of action, including membrane destabilization, disruption, and cell wall hydrolysis, actions that were not observed with the single nanoparticle counterparts. To understand the fundamental working mechanisms behind the improved performance of coassembled nanoparticles, we utilized a "dilution effect" system where the antibacterial components are intermolecularly mixed and coassembled with a non-antibacterial protein in the nanoparticles. We suggest that coassembled nanoparticles mediate enhanced bacterial killing activity by attributes such as optimized local concentration, high avidity, cooperativity, and synergy. The nanoparticles showed no cytotoxic or hemolytic activity against tested eukaryotic cells and erythrocytes. Collectively, these findings reveal potential strategies for disrupting the impermeable barrier that Gram-negative pathogens leverage to restrict antibacterial access and may serve as a platform technology for potential nano-antibacterial design to strengthen the declining antibiotic arsenal.

A dedicated hypothalamic oxytocin circuit controls aversive social learning.

To survive in a complex social group, one needs to know who to approach and, more importantly, who to avoid. In mice, a single defeat causes the losing mouse to stay away from the winner for weeks1. Here through a series of functional manipulation and recording experiments, we identify oxytocin neurons in the retrochiasmatic supraoptic nucleus (SOROXT) and oxytocin-receptor-expressing cells in the anterior subdivision of the ventromedial hypothalamus, ventrolateral part (aVMHvlOXTR) as a key circuit motif for defeat-induced social avoidance. Before defeat, aVMHvlOXTR cells minimally respond to aggressor cues. During defeat, aVMHvlOXTR cells are highly activated and, with the help of an exclusive oxytocin supply from the SOR, potentiate their responses to aggressor cues. After defeat, strong aggressor-induced aVMHvlOXTR cell activation drives the animal to avoid the aggressor and minimizes future defeat. Our study uncovers a neural process that supports rapid social learning caused by defeat and highlights the importance of the brain oxytocin system in social plasticity.

Design and synthesis of novel 3-amino-5-phenylpyrazole derivatives as tubulin polymerization inhibitors targeting the colchicine-binding site

As the basic unit of microtubules, tubulin is one of the most important targets in the study of anticarcinogens. A novel series of 3-amino-5-phenylpyrazole derivatives were designed and synthesized, and evaluates for their biological activities. Among them, a majority of compounds exerted excellent inhibitory activities against five cancer cell lines in vitro. Especially, compound 5b showed a strong antiproliferative activity against MCF-7 cells, with IC50 value of 38.37 nM. Further research indicated that compound 5b can inhibit the polymerization of tubulin targeting the tubulin colchicine-binding sites. Furthermore, 5b could arrest MCF-7 cells at the G2/M phase and induce MCF-7 cells apoptotic in a dose-dependent and time-dependent manners, and regulate the level of related proteins expression. Besides, compound 5b could inhibit the cancer cell migration and angiogenesis. In addition, 5b could inhibit tumor growth in MCF-7 xenograft model without obvious toxicity. All these results indicating that 5b could be a promising antitumor agent targeting tubulin colchicine-binding site and it was worth further study.

Phosphonium-Substituted Conjugated Polyelectrolytes Display Efficient Visible-Light-Induced Antibacterial Activity.

We report the light-activated antibacterial activity of a new class of phosphonium (R-PMe3+)-substituted conjugated polyelectrolytes (CPEs). These polyelectrolytes feature a poly(phenylene ethynylene) (PPE) conjugated backbone substituted with side groups with the structure -O-(CH2)nPMe3+, where n = 3 or 6. The length of the side groups has an effect on the hydrophobic character of the CPEs and their propensity to interact with bacterial membranes. In a separate study, these phosphonium-substituted PPE CPEs were demonstrated to photosensitize singlet oxygen (1O2) and reactive oxygen species, a key factor for the photoinduced inactivation of bacteria. In this study, in vitro antibacterial assays against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were performed by employing the series of polyelectrolytes under both dark and illumination conditions. In general, the phosphonium-substituted CPEs displayed profound light-activated biocidal activity, with >99% colony forming unit (CFU) reduction after 15 min of light exposure (16 mW cm-2) at a ≤20 μM CPE concentration. Strong biocidal activity was also observed in the dark for a CPE concentration of 20 μM against S. aureus; however, higher concentrations (200 μM) were needed to enable dark inactivation of E. coli. The dark activity is ascribed to bacterial membrane disruption by the CPEs, supported by a correlation of dark biocidal activity with the chain length of the side groups. The light-activated biocidal activity is associated with the ability of the CPEs to sensitize ROS, which is cytotoxic to the microorganisms. Serial dilution bacterial plating experiments revealed that the series of CPEs was able to induce a >5-log kill versus E. coli with 15 min of exposure to a blue LED source (16 mW cm-2).

P164 MRT-6160, a VAV1-directed molecular glue degrader, inhibits disease progression and inflammation in a T-cell transfer model of Colitis

Abstract Background VAV1 is an immune-restricted guanine nucleotide exchange factor critical for T-cell receptor (TCR) and B-cell receptor (BCR) signalling. The role of VAV1 in T-cells has been demonstrated in knockout mice, which exhibit decreased effector functions and resistance to autoimmune disease models, and in CRISPR-based screens, where VAV1 has been highlighted as a top hit among positive regulators of T-cell function. Until now, VAV1 has remained undruggable by conventional small molecules. MRT-6160 is a first-in-class molecular glue degrader that specifically targets VAV1 for proteasomal degradation. Given the role of VAV1 in TCR and BCR signalling, MRT-6160-mediated degradation could be an effective therapeutic approach to treating autoimmune disease. Methods We first tested the impact of MRT-6160-mediated human (h)VAV1 degradation on primary human cells using in vitro stimulation-based assays. Oral bioavailability of MRT-6160 and in vivo degradation of murine (m)VAV1 was then examined in mice. We tested the efficacy of MRT-6160 using a T-cell adoptive transfer model of colitis treating recipients of pathogenic CD45RBhigh CD4+ T-cells (8 per group) with anti-TNF (25 mg/kg, Q3D) or MRT-6160 (1 mg/kg, QD) for 41 days following cell transfer. Disease activity index (DAI), comprising stool consistency and weight loss, was assessed every 3 days. At study termination, mesenteric lymph nodes (mLN) were profiled by flow cytometry and colon tissues were assessed for cytokine expression and histopathology. Results Degradation of hVAV1 by MRT-6160 inhibited T-cell activation, proliferation, and cytokine production in a dose-dependent manner. Orally administered MRT-6160 degraded mVAV1 and inhibited colitis disease progression by 85%, reducing average end point DAI scores more than a standard of care control (vehicle, p<0.0001; anti-TNF, p=0.0107). Compared to vehicle treated groups, MRT-6160 treated mice had fewer IL-17A+ (12.6 and 5.3% respectively) and TNF+ (37.6 and 17% respectively) CD4+ T cells in mLN tissue. Colon weight:length ratio was significantly reduced in MRT-6160-treated mice (42.5 mg/cm) compared to vehicle (70.3 mg/cm) and anti-TNF (61.2 mg/cm). Finally, pro-inflammatory cytokine expression in the colon mucosa was reduced in MRT-6160-treated mice compared to vehicle (IL-6: 1305.8 and 682.3 fg/mg; TNF: 175.5 and 66.9 ng/mg; respectively), as well as histopathological evidence of disease. Conclusion MRT-6160 demonstrates strong activity in a preclinical model of colitis reducing DAI, effector cytokine production, and colon tissue damage. These data suggest that MRT-6160-mediated degradation of VAV1 may have therapeutic benefit in IBD patients and warrants further clinical development.

Synthesis and Biological Evaluation of 2-Azolylmethylene-3-(2H)-benzofuranone Derivatives as Potent Monoamine Oxidases Inhibitors.

A series of 2-azolylmethylene-3-(2H)-benzofuranone derivatives, 2-indolylmethylene-3-(2H)-benzofuranone and 2-pyrrolylmethylene-3-(2H)-benzofuranone derivatives, were synthesized, and their monoamine oxidase (MAO) A and B inhibitory activities were evaluated. Compounds 1b, 3b, 6b, 7b, and 10b showed strong inhibitory activity against MAO-A, and compound 3b showed the highest potency and selectivity, with an IC50 value of 21 nM and a MAO-A selectivity index of 48. Compounds 3c, 4c, 9a, 9c, 10c, 11a, and 11c showed strong inhibitory activity against MAO-B, and compound 4c showed the highest potency and selectivity, with an IC50 value of 16 nM and a MAO-B selectivity index of >1100. Further analysis of these compounds indicated that compound 3b for MAO-A and compound 4c for MAO-B were competitive inhibitors, with Ki values of 10 and 6.1 nM, respectively. Furthermore, computational analyses, such as quantitative structure-activity relationship (QSAR) analysis of the 2-azolylmethylene-3-(2H)-benzofuranone derivatives conducting their pIC50 values with the Molecular Operating Environment (MOE) and Mordred, and molecular docking analysis using MOE-Dock supported that the 2-azolylmethylene-3-(2H)-benzofuranone derivatives are a privileged scaffold for the design and development of novel MAO inhibitors.

Development of microencapsulated dried Bacillus sp. 63‐11 with enhanced shelf stability and bioactivity for use as a food supplement

SummaryThe impact of drying processes and encapsulation techniques of Bacillus sp. 63‐11 was explored in relation to the stability and bioactive properties of microencapsulated particles. Modified starch (MS) or maltodextrin (MD) were evaluated using freeze drying (FD) or hot‐air drying (HD) protocols. The HD‐dried cells showed significantly improved viability and appearance when compared to FD. HD‐MD cells exhibited 2 log CFU higher viability, lower contamination, and deeper pigmentation than HD‐MS, and superior gastrointestinal tolerance as compared to fresh cells during storage, enhanced it's probiotic potential. HD‐MD cells also exhibited dose‐dependent antibiotic susceptibility, strong antagonistic activities and consistently high antioxidant activity, i.e., Trolox equivalent antioxidant capacity at 0.4 g mL−1. Additional shelf‐life testing in five food models for 90 days revealed remarkable bio‐preservative potential, particularly in high‐fat models. The study highlights the impact on probiotic potential and bioactivity of hot air‐dried encapsulated Bacillus species.

Catalytic Antioxidant Activity of Two Diterpenoid Polyphenols of Rosemary, Carnosol, and Isorosmanol, against Lipid Oxidation in the Presence of Cysteine Thiol.

Lamiaceae herbs such as rosemary have excellent antioxidant properties, and lipidic diterpenoid constituents, such as carnosol, are known as characteristic components to exhibit strong antioxidant activity. This study investigates the effect of thiol compounds on the antioxidant properties of diterpenoid polyphenols. The results concerning the antioxidant activity of polyphenols in the presence of thiol showed that two polyphenols, namely, carnosol and isorosmanol, enhanced antioxidant capacity against the radical-induced oxidation of lipids. Further examination of the mechanism revealed that both polyphenols exhibit excellent catalytic antioxidant activity by using the thiol group as a reduction source. Using density functional theory calculations, we attempted to explain why only these two polyphenols exhibit catalytic antioxidant properties. The calculation results and the assumed reaction mechanism suggested that the orthoquinones produced in the antioxidant reactions of carnosol and isorosmanol are more unstable than the others and that the regioselectivity of their reactions with thiols contributes to their catalytic antioxidant properties.

Photo-Assisted Li-N2 Batteries with Enhanced Nitrogen Fixation and Energy Conversion.

Li-N2 batteries have received widespread attention for their potential to integrate N2 fixation, energy storage, and conversion. However, because of the low activity and poor stability of cathode catalysts, the electrochemical performance of Li-N2 batteries is suboptimal, and their electrochemical reversibility has rarely been proven. In this study, a novel bifunctional photo-assisted Li-N2 battery system was established by employing a plasmonic Au nanoparticles (NPs)-modified defective carbon nitride (Au-Nv -C3 N4 ) photocathode. The Au-Nv -C3 N4 exhibits strong light-harvesting, N2 adsorption, and N2 activation abilities, and the photogenerated electrons and hot electrons are remarkably beneficial for accelerating the discharge and charge reaction kinetics. These advantages enable the photo-assisted Li-N2 battery to achieve a low overpotential of 1.32 V, which is the lowest overpotential reported to date, as well as superior rate capability and prolonged cycle stability (≈500 h). Remarkably, a combination of theoretical and experimental results demonstrates the high reversibility of the photo-assisted Li-N2 battery. The proposed novel strategy for developing efficient cathode catalysts and fabricating photo-assisted battery systems breaks through the overpotential bottleneck of Li-N2 batteries, providing important insights into the mechanism underlying N2 fixation and storage.

Designing nanostructured lipid carriers modified with folate-conjugated chitosan for targeted delivery of osthole to HT-29 colon cancer cells: investigation of anticancer, antioxidant, and antibacterial activities

AbstractThe present study proposed to design nanostructured lipid carriers (NLC) coated with chitosan (CS) conjugated folate (FA) for the targeted delivery of Osthole (OST) to the HT-29 colon cancer cell line and improve its anticancer capability. To assess the physicochemical characteristics of OST-loaded NLC decorated with CS-conjugated FA (OST-NCF-NPS), several techniques, including DLS, SEM, and FTIR, were applied. After determining the encapsulation efficiency of OST in CSFA-modified NLC-NPs, an MTT test was conducted to evaluate the cytotoxic effects of this nano platform on the HT-29 cancer cell line in comparison to normal HFF cells. Possible mechanisms of apoptosis in cancer cells treated with OST-NCF-NPs were examined using qPCR, flow cytometry, and AO/PI fluorescent staining methods. Moreover, the antioxidant capacity of these biosynthesized nanocarriers was determined using ABTS and DPPH methods, and their antibacterial potential was measured through disk diffusion, MIC, and MBC assays. According to the findings, OST-NCF-NPS had the ideal average size of 179.19 nm, low polydispersity (PI = 0.23), acceptable physical stability (ζ-potential = + 18.99 mV), and high entrapment efficiency (83.5%). The MTT data demonstrated the selective cytotoxicity of NPs toward cancerous cells compared to normal cells. Cell cycle and Annexin V/Propidium Iodide (AnV/PI) analysis indicated that OST-NCF-NPs increased the sub-G1 population and AnV/PI-positive cells. The occurrence of programmed cell death in the treated cells was also verified by altered expression of proapoptotic (BAX and caspase-3) and antiapoptotic (Bcl-2) genes. Furthermore, the NPs exhibited strong antibacterial activity, particularly against gram-negative bacteria, and high antioxidant effects in reducing ABTS and DPPH-free radicals. Graphical Abstract

Evaluation of the potential of endophytic Trichoderma sp. isolated from medicinal plant Ampelopsis japonica against MRSA and bioassay-guided separation of the anti-MRSA compound.

Endophytic fungi have been recognized as a valuable source for the production of biologically active compounds with potential applications in various domains. This study aimed to isolate endophytic fungi from Ampelopsis japonica (Thunb.) Makino and assess their anti-MRSA activity. Meanwhile, chromatographic separation techniques were applied to analyze the constituents of endophytic fungal secondary metabolites. The isolate BLR24, which exhibited strong inhibition activity against MRSA, was identified as Trichoderma virens based on morphological characteristics and ITS sequence analyses. The ethyl acetate extract of BLR24 (EA-BLR24) showed good anti-MRSA activity with the MIC and MBC values of 25 μg/mL and 50 μg/mL, separately. The inhibition of biofilm formation was up to 34.67% under MIC concentration treatment. Meanwhile, EA-BLR24 could significantly reduce the expression of biofilm-related genes (icaA, sarA, and agrA) of MRSA. Based on LC-MS/MS analysis, twenty compounds in EA-BLR24 could be annotated using the GNPS platform, mainly diketopiperazines. The anti-MRSA compound (Fr.1.1) was obtained from EA-BLR24 by bioassay-guided fractionation and determined as gliotoxin. The results indicated that endophytic Trichoderma virens BLR24 isolated from the medical plant A. japonica roots could be a promising source of natural anti-MRSA agents. Endophytic fungal secondary metabolites are abundant in biologically active compounds. Endophytic fungi from medicinal plants could be a source yielding bioactive metabolites of pharmaceutical importance.

Synthesis, antitumor activity evaluation of 2-selenocyano-3-selenocyanoalkyloxyestradiols with a bisselenocyanate structure

The combination of steroid structure and selenocyano group offers high potential for the design and synthesis of new potential anti-tumor drugs. Beginning with estradiol, a series of 2-selenocyano-3-selenocyanoalkyloxyestradiol derivatives with remarkable antiproliferative activity was synthesized. Additionally, a 2,4-bisselenocyanoestradiol was synthesized by directly selenocyanating estradiol diacetate. It was found that the cytotoxicity of 2-selenocyano-3-selenocyanoalkyloxyestradiol derivatives was significantly increased in comparison to the corresponding monoselenocyanate precursor, whereas the cytotoxicity of the 2, 4-bisselenocyanoestradiol derivative was significantly reduced compared to the respective monosubstituted precursor. The introduction of the second selenocyano group at different locations of estradiol shows a various impact on the cytotoxicity of the compounds. Among them, compound 3e showed the best cytotoxicity, with an IC50 value of less than 5 μM against the tested tumor cells, and strong inhibitory activities against HeLa and MCF-7 cell xenograft tumors in zebrafish, suppressing tumor cell migration and neovascularization. Notably, compound 3e was more effective at inhibiting neovascularization of MCF-7 cell xenograft tumors than the positive control 2-methoxyestradiol. Furthermore, compound 3e showed excellent anti-oxidative stress effect in zebrafish. Therefore, these estrogen bisselenocyanate compounds may be promising anti-tumor agents, warranting further investigation.

Probiotic fermentation affects the chemical characteristics of coix seed-chrysanthemum beverage: Regulatory role in sensory and nutritional qualities

Probiotic fermentation is attractive for beverage processing. However, its regulatory role in quality of coix seed-chrysanthemum beverage (CCB) rich in phenolics and polysaccharides was unknown. Results showed that co-fermentation with Bifidobacterium animalis subsp. lactis BLa80 (BLa80), Lactobacillus delbrueckii subsp. bulgaria LB42 (LB42), Streptococcus salivarius subsp. thermophilus ST81 (ST81), and Lactobacillus plantarum LP90 (LP90) for 12 h combined their respective advantages to prepare fermented CCB with viable counts of 8.78 lg CFU/mL, high phenolics bioaccessibility (>60 %), good sensory quality, and strong antioxidant activity. LP90 greatly contributed to the aroma. BLa80 and LP90 hydrolyzed resistant starch/polymer dextrin. BLa80 showed the strongest deglycosidic ability, decreasing bitterness. The compound probiotic fermentation led to the biotransformation of endogenous polysaccharides/phenolics and introduction of exogenous viable probiotics resistant to gastrointestinal digestion, facilitating the proliferation of beneficial gut microbiota and accumulation of their metabolites. These findings provided a useful strategy for dual regulation of high quality of plant-based beverage.

Metagenomic analysis of hot spring soil for mining a novel thermostable enzybiotic.

The misuse and overuse of antibiotics have contributed to a rapid emergence of antibiotic-resistant bacterial pathogens. This global health threat underlines the urgent need for innovative and novel antimicrobials. Endolysins derived from bacteriophages or prophages constitute promising new antimicrobials (so-called enzybiotics), exhibiting the ability to break down bacterial peptidoglycan (PG). In the present work, metagenomic analysis of soil samples, collected from thermal springs, allowed the identification of a prophage-derived endolysin that belongs to the N-acetylmuramoyl-L-alanine amidase type 2 (NALAA-2) family and possesses a LysM (lysin motif) region as a cell wallbinding domain (CWBD). The enzyme (Ami1) was cloned and expressed in Escherichia coli, and its bactericidal and lytic activity was characterized. The results indicate that Ami1 exhibits strong bactericidal and antimicrobial activity against a broad range of bacterial pathogens, as well as against isolated peptidoglycan (PG). Among the examined bacterial pathogens, Ami1 showed highest bactericidal activity against Staphylococcus aureus sand Staphylococcus epidermidis cells. Thermostability analysis revealed a melting temperature of 64.2 ± 0.6°C. Overall, these findings support the potential that Ami1, as a broad spectrum antimicrobial agent, could be further assessed as enzybiotic for the effective treatment of bacterial infections. KEY POINTS: • Metagenomic analysis allowed the identification of a novel prophage endolysin • The endolysin belongs to type 2 amidase family with lysin motif region • The endolysin displays high thermostability and broad bactericidal spectrum.

A promising antifungal lipopeptide from Bacillus subtilis: its characterization and insight into the mode of action.

Emerging resistance of fungal pathogens and challenges faced in drug development have prompted renewed investigations into novel antifungal lipopeptides. The antifungal lipopeptide AF3 reported here is a natural lipopeptide isolated and purified from Bacillus subtilis. The AF3 lipopeptide's secondary structure, functional groups, and the presence of amino acid residues typical of lipopeptides were determined by circular dichroism, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The lipopeptide's low minimum inhibitory concentrations (MICs) of 4-8mg/L against several fungal strains demonstrate its strong antifungal activity. Biocompatibility assays showed that~ 80% of mammalian cells remained viable at a 2 × MIC concentration of AF3. The treated Candida albicans cells examined by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy clearly showed ultrastructural alterationssuch as the loss of the cell shape and cell membrane integrity. The antifungal effect of AF3 resulted in membrane permeabilization facilitating the uptake of the fluorescent dyes-acridine orange (AO)/propidium iodide (PI) and FUN-1. Using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 4-(2-[6-(dioctylamino)-2-naphthalenyl] ethenyl)-1-(3-sulfopropyl) pyridinium inner salt (di-8-ANEPPS), we observed that the binding of AF3 to the membrane bilayer results in membrane disruption and depolarization. Flow cytometry analyses revealed a direct correlation between lipopeptide activity, membrane permeabilization (~ 75% PI uptake), and reduced cell viability. An increase in 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence demonstrates endogenous reactive oxygen species production. Lipopeptide treatment appears to induce late-stage apoptosis and alterations to nuclear morphology, suggesting that AF3-induced membrane damage may lead to a cellular stress response. Taken together, this study illustrates antifungal lipopeptide's potential as an antifungal drug candidate. KEY POINTS: • The studied lipopeptide variant AF3 displayed potent antifungal activity against C. albicans • Its biological activity was stable to proteolysis • Analytical studies demonstrated that the lipopeptide is essentially membranotropic and able to cause membrane dysfunction, elevated ROS levels, apoptosis, and DNA damage.

Antioxidant and Antibacterial Activity of Endophytic Fungi Isolated from Fruit of Sungkai (Peronema canescens)

Peronema canescens, often known as sungkai, is widely used and can be found all around Indonesia. The public believes that the leaves may reduce fever and strengthen the immune system. However, the effectiveness of sungkai fruit has not been thoroughly investigated. In this research, we looked at endophytic fungus extracts from sungkai fruit’s that have antioxidant and antibacterial properties. The study’s results will serve as the foundation for further investigation into the development of potential natural chemicals with antioxidant and antibacterial properties. Morphologically, the endophytic fungi isolated from sungkai fruit were identified. The antioxidant and antibacterial properties of endophytic fungal extracts were studied using the DPPH technique and the paper disk diffusion method. By employing molecular identification and column chromatography to separate the active compounds, the most likely endophytic fungal isolates were found based on the results of the bioactivity tests. Using 1D NMR spectroscopic methods, the chemical’s structure was determined, and the results were compared to NMR data for the same compound published in the literature. Fruit of sungkai had 8 strains of endophytic fungus (RBH1-RBH8). Strong antibacterial and very strong antioxidant activity were shown by the RBH5 isolate (IC50 < 20 μg/mL). Pythium periplocum was determined to be the RBH5 isolate based on molecular testing. Pure chemical compound extracted from RBH5 isolates shown highly potent and potent antibacterial and antioxidant effects. The chemical compound was identified by spectroscopy as 3-hydroxy-4(hydroxy(4-hydroxyphenyl)methyl)-γ-butyrolactone. The results of this study serve as the foundation for developing compounds as pharmaceutical raw materials via further research phases.

Influence of β-Ionone in the Phytotoxicity of the Rhizome of Iris pallida Lam.

Iris pallida Lam., also known as Sweetie Iris, is a perennial ornamental and medicinal plant that produces a wide range of secondary metabolites. The Sweetie Iris was recently reported to have high allelopathic properties with the potential to be explored in sustainable weed management. This study aimed to identify and evaluate the contributions of compounds involved in the inhibitory effects of the rhizome of Sweetie Iris. High-performance liquid chromatography (HPLC) analysis was used to determine the content of β-ionone in the rhizome of Sweetie Iris. The phytotoxicity of β-ionone was evaluated on lettuce (Lactuca sativa L.) and other test plants. The content of β-ionone in the crude extract of Sweetie Iris rhizome was found to be 20.0 mg g-1 by HPLC analysis. The phytotoxicity bioassay showed that β-ionone had strong inhibitory activity on the growth of lettuce (Lactuca sativa L.) and the other test plants, including Taraxacum officinale, Stellaria media, Eleusine indica, Amaranthus hybridus, Vicia villosa, and Brassica napus. At a concentration of 23.0 µg mL-1, β-ionone inhibited the growth of all test plant species treated. Therefore, β-ionone is an active compound among the other allelopathic substances contained in the rhizome of Sweetie Iris.

Isolation and characterization of lactic acid bacteria producing a potent anti-listerial bacteriocin-like inhibitory substance (BLIS) from chhurpi, a fermented milk product.

Nowadays, the bacteriocin industries have seen significant growth, supplanting chemical preservatives in its ability to improve the shelf-life and safety of food. The increasing customer desire to use natural preservatives has fueled advancing bacteriocin research. The objective of this study was to identify lactic acid bacteria (LAB) that produce bacteriocin-like inhibitory substance (BLIS) and have strong anti-listerial activity. We have identified and analyzed a LAB obtained from chhurpi samples, a popular milk-derived product in the Himalayan regions of India and Nepal. The strain was studied and identified based on its morphological, biochemical, and physiological characteristics. Furthermore, the molecular 16s-rDNA analysis suggests that the strain was Lactococcus sp. RGUAM1 (98.2% similar to Lactococcus lactis subsp. hordniae NBRC 100931T). The isolated strain can produce a potent BLIS, which has shown efficacy against three gram-positive bacteria responsible for food spoilage, such as Listeria monocytogenes (MTCC 657), Staphylococcus aureus subsp. aureus (MTCC 87), Lactobacillus plantarum (MTCC 1407), Lactobacillus paraplantarum (MTCC 12904). The scanning electron microscope (SEM) image illustrates that the crude cell-free supernatant (CFS) disrupts the cell envelope, leading to the release of cellular contents and the clustering of cells. In addition, this BLIS can easily withstand a wide range of pH (2-12), temperature (up to 100°C for 15min), bile salt (0.3% W/V), salinity (4% W/V), and enzyme activity of 1600AU/ml against Listeria monocytogenes. Our research offers a robust framework and valuable insights into bio-preservation and its potential applications in diverse food products.