Ethnobotany and the Role of Plant Natural Products in Antibiotic Drug Discovery

Antimicrobial capping agents on silver nanoparticles made via green method using natural products from banana plant waste

Herein, we investigated the phytochemical composition and antibacterial activities of the organic layers from biosynthesized silver nanoparticles (AgNPs). AgNPs were synthesized using Musa paradisiaca and Musa sapientum extracts. UV-vis absorption in the 400-450 nm range indicated surface plasmonic resonance peak of AgNPs. Samples analyses using dynamic light scattering and transmission electron microscopy revealed the presence of particles within nanometric ranges, with sizes of 30-140 nm and 8-40 nm, respectively. Fourier transform infrared (FTIR) unveiled the presence of several organic functional groups on the surface of AgNPs, indicating the presence of phytochemicals from plant extracts. Thin layer chromatography (TLC) of the phytochemicals (capping agents) from AgNPs identified multiple groups of secondary metabolites. These phytochemical capping agents exhibited antibacterial activities against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, with minimum inhibitory concentrations ranging from 62.5 to 1000 µg/mL. Regardless of the bacterial species or plant parts (leaves or pseudo-stems), capping agents from M. sapientum nanoparticles displayed significantly enhanced antibacterial effectiveness compared to all other samples, including the raw plant extracts and biosynthesized capped and uncapped AgNPs. These results suggest the presence of antimicrobial phytochemicals on biosynthesized AgNPs, highlighting the promise of green nanoparticle synthesis as a valuable approach in bioprospecting antimicrobial agents.

New advances of natural products in non-small cell lung cancer: From mechanisms to therapies

ETHNOPHARMACOLOGICAL RELEVANCE

With the rise of immunotherapy, the treatment approach for non-small cell lung cancer (NSCLC) has undergone revolutionary changes. However, the prognosis for NSCLC patients has not been significantly improved due to the development of acquired drug resistance. Therefore, there is an urgent need to develop new and more effective drugs for treating NSCLC or improving tumor treatment resistance. Traditional Chinese medicine (TCM) has been gradually incorporated into the combined treatment of NSCLC. Its active components (also known as natural products) exhibit novel structures, multi-target effects, diverse pathways, minimal toxicity, and varied biological activities, which play a therapeutic role in various diseases. Thus, natural products hold great potential for future clinical applications.

AIM OF THE STUDY

Screening main traditional plants widely used in NSCLC and their derived natural products, as well as exploring the mechanisms by which these natural products act on NSCLC-particularly focusing on their applications-can provide valuable insights for the development of therapeutic drugs targeting NSCLC.

METHODS

A comprehensive, computerized literature search was conducted in PubMed, Embase, Web of Science, Cochrane Library, CNKI Scholar, the American Chemical Abstracts, and Wanfang Database up to June 2024, using the following keywords: "traditional Chinese medicine", "herbal medicine", "medicinal plants", and "herbal", paired with terms such as "non-small cell lung cancer", "therapy", "natural products", and "active ingredient".

RESULTS

Summarizing current research findings, we discovered eleven medicinal plants containing a total of fourteen natural products. Natural products have a significant impact on tumor progression in NSCLC, including apotosis, autophagy, pyrotosis, cell-cycle arrest and metasis. Moreover, natural products can modulate the activities of various immune cells and reshape the immune microenvironment. Combined with conventional cancer treatments, natural products demonstrate promising therapeutic effects and effectively reverse drug resistance. Furthermore,the use of nano-drug delivery systems to address limitations associated with natural products.

CONCLUSIONS

This review summarizes eleven medicinal plants containing a total of fourteen natural products that can enhance NSCLC treatment and indicates their action mechanisms. Furthermore, we also discuss limitations of natural products and explore the use of nano-drug delivery systems to address limitations associated with natural products.

Drug resistance detection of canine origin Escherichia coli in China and inhibition by genipin

Zoonotic transmission from pets to their owners is a major health problem. It is important to determine and control the drug resistance in pets to mitigate risks of human transmission. In this work, the current prevalence of multi-drug resistance (MDR) and resistance gene in Escherichia coli (E. coli) derived from dogs in nine cities across various regions of China initially evaluated using microfluidic dilution methods and polymerase chain reaction (PCR) technology. To control antibiotic resistance, genipin as natural product was used to combat MDR E. coli. Finally, the synergistic effect of genipin and norfloxacin on MDR E. coli was studied using time-kill curves to retard the resistance spread. A total of 126 E. coli strains were isolated from 154 collected fecal samples of dogs. Minimum inhibitory concentrations (MIC) results revealed that the highest detection rate of MDR E. coli appeared in Zhengzhou at 90.9 %, and the lowest in Shenyang at 10.0 %. The results of drug resistance gene testing indicated that the blaTEM gene had the highest detection rate (99.2 %), then tetA and blaCTX-M-1, whose detection rates all exceed 50 %. Furthermore, the MIC of genipin against MDR E. coli was found to be 4096 μg/mL, and genipin at ½ MIC demonstrated significant inhibition on MDR E. coli within 6 h. Finally, the combination of ¼ MIC genipin with ½ MIC norfloxacin showed partial synergistic inhibitory effect on MDR E. coli. Our findings suggest that although antibiotic resistance in canine origin E. coli varies across different regions of China, it remains concerning, and genipin shows potential as a treatment option for MDR E. coli infections.

Total synthesis and antibacterial evaluation of lupalbigenin and isolupalbigenin

Lupalbigenin (1) is an antibacterial isoflavone isolated from Maclura cochinchinensis (Lour.) Corner (Moraceae). In this study, we achieved the first gram-scale synthesis of lupalbigenin (1) from commercially available genistein (2), with a yield of 47.7%. The key step was a Claisen rearrangement that simultaneously installed two prenyl groups at the C-6 and C-11 positions of lupalbigenin (1). Antimicrobial activity assays revealed that lupalbigenin (1) exhibited rapid bactericidal activity, inhibited α-hemolysin and biofilm formation, and disrupted bacterial cell membranes. These findings suggest that lupalbigenin (1) is a promising candidate for the development of novel antibiotics to combat bacterial infections.

Enhanced antibacterial effect of blue light in combination with an Amazonian tree sap (Croton lechleri)

In the United States, 8.2 million patients suffer from non-healing wounds which are often infected with antibiotic-resistant bacteria. Blue light (BL) and Sangre de Drago (Croton lechleri, SD) have potent mechanisms of antibacterial action through free radical formation and anti-biofilm effect, respectively. The aim of this pilot study was to evaluate the enhanced antibacterial effect of a novel combination treatment consisting of blue light and Sangre de Drago. Preliminary dosimetry measurements for effective SD concentration (5%) and 415-nm blue LED light fluence (125.3 J/cm2 with a standard variation of 5 mW) were performed. E. coli K-12 (volume 0.1-mL, concentration 2 × 105CFU/mL) was applied to each of 32 tryptic soy agar (TSA) plates. Inoculated TSA plates were separated into four groups: (1) no treatment (Control), (2) treatment with SD only, (3) treatment with blue light (BL) only, and (4) treatment with both SD and BL. Plates were incubated for 12 h at 37°C. Colony-forming units (CFUs) were analyzed using Image J software and count, size and overal TSA plate coverage were quantified. The median CFU count was highest in the Control group (157.9, interquartile range [IQR]: 112.0-157.9), followed by SD-only (60.5, IQR: 51.6-93.6), BL-only (33.7, IQR: 23.6-45.2), while no bacterial growth was observed in the combination treatment group (0, IQR: 0-0). The median CFU size was largest for control (0.44 mm2, IQR: 0.35-0.59 mm2), followed by BL-only (0.28 mm2, IQR: 0.19-0.43 mm2) and SD-only (0.16 mm2, IQR: 0.11-0.23 mm2). BL-only caused a marked reduction in total CFU count, while the median CFU size was only moderately decreased compared to Control. The significant reduction in CFU count may be due to the bactericidal action of BL on bacteria. Conversely, SD-only caused just a moderate decrease in CFU count but had the largest decrease in median CFU size, indicating a possible strong bacteriostatic mechanism of action by SD. The combination of BL and SD resulted in no bacterial growth. The Bliss independence model demonstrated a Bliss synergy value of 0.04 indicating low synergy between the two treatments, even though its presence was significant (p = 0.001). This initial investigation on the combination treatment using 5% SD and 415-nm BL demonstrates synergy resulting in an enhanced antibacterial effect compared to each treatment alone. Further investigation and validation of these results is required. If validated, this novel combination approach may be translated to clinical practice to help treat chronic wounds infected with antimicrobial-resistant bacteria, using non-traditional antimicrobial agents that bypass the most common bacterial mechanisms of antibiotic resistance.

Metal-based nanoplatforms for enhancing the biomedical applications of berberine: current progress and future directions

The isoquinoline alkaloid berberine, a bioactive compound derived from various plants, has demonstrated extensive therapeutic potential. However, its clinical application is hindered by poor water solubility, low bioavailability, rapid metabolism, and insufficient targeting. Metal-based nanoplatforms offer promising solutions, enhancing drug stability, controlled release, and targeted delivery. This review comprehensively explores the synthesis, physicochemical properties, and biomedical applications of metal-based nanocarriers, including gold, silver, iron oxide, zinc oxide, selenium, and magnetic nanoparticles, for berberine delivery to improve berberine's therapeutic efficacy. Recent advancements in metal-based nanocarrier systems have significantly improved berberine delivery by enhancing cellular uptake, extending circulation time, and enabling site-specific targeting. However, metal-based nanoplatforms encounter several limitations of potential toxicity, limited large-scale productions, and regulatory constraints. Addressing these limitations necessitates extensive studies on biocompatibility, long-term safety, and clinical translation. By summarizing the latest innovations and clinical perspectives, this review aims to guide future research toward optimizing berberine-based nanomedicine for improved therapeutic efficacy.

Unexpected Efficacy of Albumin-Bound Glycerol Monolaurate Against Multidrug-Resistant Bacterial Isolates: A Time-Kill Assay Study

Background

The rise of antibiotic resistance is a significant threat to global health, necessitating the exploration of novel antimicrobial agents. Glycerol monolaurate (GML) is known for its antimicrobial properties, primarily against Gram-positive bacteria, with limited evidence of efficacy against Gram-negative pathogens.

Methods

This study evaluated the antibacterial activity of GML alone and in combination with human serum albumin (HSA) against clinical isolates of carbapenem-resistant and vancomycin-resistant bacteria using MIC and time-kill assays.

Results

Contrary to previous reports, we demonstrate that GML exhibits significant antibacterial activity against Gram-negative bacteria, including strains resistant to conventional antibiotics. It inhibited carbapenem-resistant isolates with MIC values ranging from 25 to 100 μg/mL for E. coli, K. pneumoniae, and E. cloacae and showed bacteriostatic and bactericidal activity. The combination of HSA and GML enhanced this effect, showing potent bactericidal properties across all tested concentrations.

Conclusion

Current findings suggest that HSA-bound GML could be developed as a novel broad-spectrum antimicrobial agent targeting multidrug-resistant pathogens. Future research should focus on formulation optimization, in vivo efficacy studies, and preclinical evaluations to determine its therapeutic potential in clinical settings.

Herb-Metal Ion Coordination Compounds with Photo/Electromagnetic Wave Response for Developing Various Anti-Infection Strategies

The global rise in infectious diseases and antibiotic overuse exacerbate bacterial drug resistance, particularly in multidrug-resistant pathogens like methicillin-resistant Staphylococcus aureus (MRSA). While plant-derived flavones exhibit multi-target antibacterial mechanisms that overcome resistance, their therapeutic application remains constrained by poor aqueous dispersibility and stability. Herein, a luteolin-iron complex (Lut-Fe3⁺) is engineered through a facile coordination approach, where Fe3⁺ facilitates d-orbital splitting and generation of high-spin electrons. This octahedral complex demonstrates exceptional water dispersibility and exhibits broad-spectrum absorption across ultraviolet to microwave (MW) frequencies. Lut-Fe3⁺ demonstrates dual antimicrobial modalities: long-term antisepsis in the dark and rapid sterilization under light/MW irradiation. This multi-functional complex is further combined with various methods to develop therapeutic strategies for bacterial infections at different depths. Notably, the Lut-Fe3⁺ is engineered into an MW-responsive nebulization system, achieving effective eradication of MRSA-induced deep-tissue pneumonia in mice.

Possibility and Potenzial Intervention Targets of Saffron Extract in the Treatment of Atopic Dermatitis: A Review

Atopic dermatitis (AD) is a chronic, recurrent inflammatory skin disorder characterized by dry skin, eczema-like lesions, and severe itching. The multifaceted etiology of AD, which is not yet fully understood, includes genetic predispositions, immune dysfunctions(such as an impaired skin barrier and abnormal immune regulation), imbalances in the skin microbiota, and environmental factors, among others. In the field of AD treatment, the combination of traditional Chinese medicine and modern medicine is becoming an emerging trend. Given the potenzial side effects and reduced efficacy of conventional therapeutic drugs, Chinese herbal medicines offer patients new treatment options because of their unique efficacy and low toxicity. Some saffron extracts derived from saffron and gardenia, such as crocin, crocetin, and safranal, have shown promising potenzial in the treatment of AD. These natural ingredients not only possess anti-inflammatory and immunomodulatory properties similar to those of traditional Chinese medicines but also demonstrate excellent effects in promoting the repair of damaged skin barriers. Therefore, this article reviews the therapeutic potenzial of saffron extract in the treatment of AD, with a special focus on its mechanisms and potenzial interventions, while emphasizing the importance of herbal medicines as alternatives to traditional treatments, providing AD patients with safer and more effective treatment options.

Total synthesis of isoflavonoids

Covering: 2012 to 2024Isoflavonoids are phenolic compounds with wide structural diversity and a plethora of biological activities. Owing to their structural variation and potential health-promoting and other benefits, they have been targeted for synthesis. Herein, we review the synthesis of natural isoflavonoids belonging to different classes that include isoflavones, isoflavanones, isoflavans, isoflavenes, pterocarpans, rotenoids, coumaronochromones, and coumestans. The synthetic methodologies employed and advancements in synthetic strategies are highlighted.

Antifungal Polyacetylenic Deoxyglycosides Isolated from Endophytic Fungus Xylaria sp. VDL4 Associated with Vaccinium dunalianum

One novel C10 polyacetylene rhamnoside, 4,6,8-decatriyne-1-O-α-L-rhamnopyranoside, named xylariside A (1), together with two novel C10 polyacetylene quinovopyranosides, 4,6,8-decatriyne-1-O-α-D-quinovopyranoside, xylariside B (2), and 8E-decaene-4,6-diyne-1-O-α-D-quinovopyranoside, xylariside C (3), were obtained from the solid fermentation of Xylaria sp. VDL4, an endophytic fungus isolated from Vaccinium dunalianum wight (Ericaceae). Their chemical structures were elucidated through a combination of spectroscopic techniques. The antifungal activities of these compounds were evaluated in vitro against four phytopathogenic fungi (Fusarium oxysporum, Botrytis cinerea, Phytophthora capsici, and Fusarium solani). Compound 2 demonstrated significant antifungal activities, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 7.81 μg/mL. Compound 2's effectiveness levels were similar to those of the reference drugs thiabendazole and carbendazim (each MIC = 0.98-15.62 μg/mL). Xylariside B (2) was further evaluated against B. cinerea in vivo. It exhibited remarkable efficacy in both the prevention and treatment of tomato and strawberry gray mold. Molecular docking studies confirmed the antifungal mechanism of compound 2 by revealing its binding interactions with key enzyme targets in B. cinerea, thereby supporting the observed in vitro and in vivo results. Additionally, compound 2 showed effective inhibition of α-glucosidase, with IC50 values of 5.27 ± 0.0125 μg/mL.

Boosting the antibacterial potency of natural products through nanotechnologies

The advent of bacterial resistance has led to a notable challenge in effectively treating bacterial infections. This highlights the urgent need for the development of novel and effective drugs to combat bacterial infections. Medicinal plants, with their rich and diverse natural compounds, represent a valuable source for the discovery of novel antibacterial agents. Many of these natural compounds exhibit strong antibacterial functions, offering a promising direction for the development of antibacterial drugs. Furthermore, the application of nanotechnology in the development of antibacterial natural products has become a topic of considerable interest due to the advantages it offers, including the potential to enhance drug solubility. The efficacy of natural antibacterial agents is significantly enhanced through nanotechnology. This review offers a comprehensive overview of recent advances in the delivery of natural antibacterial compounds using a range of nanoformulation strategies.

Investigating the Antibacterial Efficiency and Mechanism of Indole- and Naphthalimide-Mediated Benzimidazoles: Membrane Damage, Metabolic Inactivation, and Oxidative Stress against Bacillus subtilis

Resistance by bacteria to available antibiotics is a threat to human health, which demands the development of new antibacterial agents. Considering the prevailing conditions, we have developed a series of naphthalimide/indole benzimidazoles with diverse amines and aryl rings to avoid the molecular framework of conventional drug molecules to overcome the cross-resistance issue. Most of the synthesized compounds, especially electron-withdrawing and halide substituents, show broad-spectrum activity against both Gram-positive and Gram-negative bacterial strains. Preliminary studies indicate that compounds IB-14 and NB-8 display excellent antibacterial activity against Bacillus subtilis, exceeding the performance of the marketed drug amoxicillin. In addition to the rapid bactericidal effect, both compounds significantly inhibit the formation of biofilm, lowering the development of drug resistance. Moreover, both compounds exhibit fast-bactericidal properties, thus shortening the time of treatment and also resisting the emergence of drug resistance up to 20 passages. Further, biofunctional evaluation reveals that both compounds effectively disrupt the membrane, causing the leakage of cytoplasmic contents and loss in metabolic activity. Both compounds efficiently induce the reactive oxygen species (ROS), leading to the oxidation of GSH to GSSG, decreasing the GSH activity of the cell, and causing oxidative damage to cells. DNA studies show that compounds significantly bind to DNA and form DNA-IB-14/NB-8 complexes that inhibit the replication of DNA and protein. The significant binding affinity of compounds with HSA suggests easy transport of the developed antibacterial candidates to the target site through the carrier protein. These findings suggest that both compounds have broad-spectrum and multitargeting potential as antibacterial agents and provide a new possibility to overcome the global issue of the development of multidrug resistance by bacteria toward conventional antibiotics.

Deprotonation-Constructed Instant Gelation Coating for Staphylococcus Disinfection and Preservation of Fresh Food in Multiple Scenarios

The ancient proverb "disease enters through the mouth" elucidates the connection between food and pathogens, underscoring the pivotal role of food preservation in preventing foodborne diseases. Drawing inspiration from ancient food preservation techniques such as waxing and the use of spices, a novel approach combining the deprotonation-induced solid-liquid phase separation of natural polymer solutions with the solubilization of plant-derived antibacterial compounds has been developed. The "two-step soaking" construction strategy enables the creation of biodegradable and adaptable for hydrogel coatings with micro-scale thickness. These multifunctional coatings can be applied to the surfaces of fresh fruits, vegetables, and meats in 35 s, providing both moisture retention and antioxidant protection. The coating's versatility allows for the targeted can achieve the elimination of various Staphylococcus and other bacterial strains through the selection of bactericides with differing antibacterial mechanisms. The scalability of this approach offers significant potential for broad applications in sterilization and food preservation in across diverse contexts.

Coastal natural products: a review applied to antimycobacterial activity

Despite the many advances in drug research, natural products are still being explored as a promising source for discovering new bioactive compounds to treat global diseases such as tuberculosis. However, there is a lack of studies and information about coastal natural products, which thrive in the transitional environment between two different ecosystems and produce unique secondary metabolites. Mangroves, estuaries, and mudflats make up areas for coastal species and have shown promising results in antituberculosis research, some of them are present in hotspot areas. This review focuses on research conducted in coastal environments and explores the reasons why these natural products tend to outperform non-coastal ones against the causative agent of tuberculosis, Mycobacterium tuberculosis.

The potential application of isoxanthohumol in inhibiting Clostridium perfringens infection by targeting the type IV pili

BACKGROUND

Clostridium perfringens (C. perfringens) is an important zoonotic pathogen. The diseases such as necrotic enteritis (NE), enterotoxemia, gas gangrene and food poisoning caused by its infection seriously threaten the lives of both humans and animals. However, under the severe situation of antibiotic resistance, the development of new antibacterial strategies or drugs deserves great attention.

RESULTS

In this study, we selected the virulence factor Type IV pili (TFP) of C. perfringens as the target for drug screening. The gliding motility, biofilm formation, cell adhesion and antibacterial activity of the natural compound isoxanthohumol (IXN) against C. perfringens were determined. Transmission electron microscopy (TEM), TFP gene transcription analysis and Western blot were used to detect the expression of PilA pilin. The therapeutic effect of IXN on C. perfringens infection was demonstrated through a mouse gas gangrene model. It was confirmed that IXN inhibits the function of TFP by down-regulating TFP-encoding genes and two-component regulatory genes.

CONCLUSIONS

In conclusion, our study shows that IXN has the potential to inhibit the function of TFP in C. perfringens and for anti-infection applications.

One-component anti-aging agents

Polymer photo-oxidation aging is a significant issue in plastics engineering, leading to reduced performance, shorter lifespan, and additional pollution. Anti-aging agents, including antioxidants and ultraviolet (UV)-shielding agents, are used to ameliorate the above problems. However, multi-component agents involve complex synthesis, mixed processing, and environmental concerns. Therefore, developing robust, multi-functional, one-component anti-aging agents is crucial. This study proposed a new class of one-component poly(coumarin) anti-aging agents, synthesized through enzymatic polymerization of coumarin. These agents exhibited a broader UV absorption spectrum and higher antioxidative capacity than commercial UV-shielding agent UV326 and antioxidant AO1010. Calculating the O-H bond dissociation energy and reaction energy barrier with peroxy free radicals (ROO˙) showed that the material could effectively attenuate UV radiation and scavenge free radicals, improving anti-aging properties. Further studies indicated the potential of poly(coumarin) anti-aging agents for enhanced polymer photostability and improved food preservation packaging. Consequently, poly(coumarin) nanoparticles can act as versatile anti-aging compounds, potentially replacing conventional multi-component agents and providing a new foundation for one-component materials with multiple functions.

Understanding the synergistic sensitization of natural products and antibiotics: An effective strategy to combat MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common multi-resistant organisms found in hospital-acquired infections and is associated with high morbidity and mortality. The development of new drugs and promising therapeutic strategies against MRSA is thus an urgent request. In recent years, some natural products have been demonstrated to show great potential in improving the efficacy of antibiotics to treat various drug-resistant bacteria, particularly MRSA. In this context, we aimed to analyze systematically from the prior arts that investigated the synergy between natural products and antibiotics against MRSA. These findings not only give us a better understanding on the mechanism of actions but also shed light on the bioactive molecular scaffolds identified from diverse natural products. In the present study, we concentratedly reviewed the studies that utilized natural products to enhance the potency of conventional antibiotics against MRSA in the last decade. The timely information reported herein may give meaningful insights into the molecular design of novel and potent antibacterial agents and/or effective therapeutics to combat MRSA for practical applications.

Norditerpene natural products from subterranean fungi with anti-parasitic activity

Cryptosporidium is a common, waterborne gastrointestinal parasite that causes diarrheal disease worldwide. Currently there are no effective therapeutics to treat cryptosporidiosis in at-risk populations. Since natural products are a known source of anti-parasitic compounds, we screened a library of extracts and pure natural product compounds isolated from bacteria and fungi collected from subterranean environments for activity against Cryptosporidium parvum. Eight structurally related norditerpene lactones isolated from the fungus Oidiodendron truncatum collected from the Soudan Iron mine in Minnesota showed potent activity and were further tested to identify the most active compounds. The availability of a diverse suite of natural structural analogs with varying activities allowed us to determine some structure activity relationships for both anti-parasitic activity as well as cytotoxicity. The two most potent compounds, oidiolactones A and B, had EC50s against intracellular Cryptosporidium parvum of 530 and 240 nM respectively without cytotoxicity to confluent HCT-8 host cells. Both compounds also inhibited the related parasite Toxoplasma gondii. Oidiolactone A was active against asexual, but not sexual, stages of C. parvum, and killed 80% of the parasites within 8 hours of treatment. This compound reduced C. parvum infection by 70% in IFNγ-/- mice, with no signs of toxicity. The high potency, low cytotoxicity, and in vivo activity combined with high production, easy isolation from fungi, and synthetic accessibility make oidiolactones A and B attractive scaffolds for the development of new anti-Cryptosporidium therapeutics.

Sulforaphane as a promising anti-caries agents: inhibitory effects on Streptococcus mutans and caries control in a rat model

Dental caries has been one of the most prevalent diseases globally over the last few decades, threatening human oral and general health. The most critical aspect in caries control is to inhibit the dominant cariogenic bacteria Streptococcus mutans (S. mutans). Sulforaphane (SFN), a compound found in a wide range of cruciferous plants, has demonstrated bacteriostatic activities against various pathogenic bacteria. The objective of the present study was to investigate the effects of SFN on S. mutans though both in vitro and in vivo experiment. The minimum inhibitory concentration (MIC) against S. mutans was determined at 256 μg/mL. The growth of S. mutans and the biofilm formation were inhibited by SFN in a dose-dependent manner through suppressing the synthesis of extracellular polysaccharide (EPS) and acid production, as well as decreasing the acid tolerance. Meanwhile, SFN significantly weakened the cariogenic properties of S. mutans at sub-inhibitory concentrations, which were further illustrated by quantitative real-time PCR (qRT-PCR). Moreover, SFN were found to inhibit quorum sensing (QS) by downregulate comCDE system in S. mutans. Further investigation using a rat caries model displayed a prominent caries control in the SFN-treated group with no observed toxicity. The notable results demonstrated in this study highlight the potential of SFN as a natural substitute for current anti-caries agents, while also providing valuable insights into the potential applications of SFN in caries control.

Alstoscholarisine L, a novel caged monoterpenoid indole alkaloid with antifungal activity from Alstonia scholaris

Alstoscholarisine L is an architecturally complex monoterpenoid indole alkaloid with a unique ring fusion pattern, isolated from the leaves of Alstonia scholaris. The 6/5/5/6/6/6-membered rings contain two lactonic rings and one aminal carbon and possess seven contiguous aligned stereocenters, three of which are quaternary. Its structure was elucidated by extensive spectroscopic data analyses, quantum chemical computations, and single-crystal X-ray diffraction. The unusual highly fused, cage-like skeleton is possibly derived from picrinine. The fascinating compound exhibited potential antifungal activity against Candida albicans, and its activity was roughly comparable to the first line antifungal drug fluconazole and significantly more effective than the plant-derived antibacterial drug berberine.

Rosmarinic Acid Restores the Ceftiofur Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus by Inhibiting Sortase A

Methicillin-resistant Staphylococcus aureus (MRSA), one of the most important zoonotic bacterial pathogens, necessitates innovative antibacterial strategies. Rosmarinic acid (RA) possesses various biological functions, including antibacterial and anti-inflammatory effects. This study aimed to explore the synergistic effects and mechanism of RA in conjunction with ceftiofur (CF) against MRSA. Results showed that the combination of RA and CF demonstrated synergistic anti-MRSA activity, conferring protective effects in an MRSA bacteremia mouse model. Mechanistic investigations further established that RA interacts with sortase A (SrtA) through hydrogen bonds, electrostatic, and van der Waals forces at critical sites, leading to the reversible inhibition of SrtA activity. Consequently, this inhibition impeded the ability of MRSA to invade cells and form biofilms. Conclusively, RA directly inhibits SrtA activity, thus enhancing the synergistic anti-MRSA effect of CF. These findings provide a theoretical foundation for the use of RA in combination with CF as a therapeutic strategy for MRSA infections.

Kaempferol restores the susceptibility of ESBLs Escherichia coli to Ceftiofur

Introduction

The development of extended-spectrum-beta-lactamase (ESBLs) Escherichia coli (E. coli) has become a global threat to public health. An alternative strategy to alleviate this is identifying potential natural compounds to restore antibiotic activity against ESBLs E. coli. This study aimed to find a possible compound to restore ESBLs E. coli sensitivity to ceftiofur.

Methods

The synergistic effect of kaempferol and ceftiofur against ESBLs E. coli was investigated by checkerboard assays, time-kill, growth curves, and scanning electronic microscope. The impact of kaempferol with ceftiofur on the biofilm of ESBLs E. coli was evaluated by crystal violet staining and laser scanning confocal microscopy and this study also assessed the effect of kaempferol on the initial adhesion and aggregation of E. coli (SY20) by examining motility, adhesion, and surface characteristics. The RT-qPCR was used to determine the effect of kaempferol on the expression of genes related to the LuxS/AI-2 quorum sensing system in ESBLs E. coli, and the effect of kaempferol on AI-2 signaling molecules was determined by molecular docking and bioassay. The impact of kaempferol on the activity of blaCTX-M-27 protein was determined by RT-qPCR, molecular docking, and nitrofen experiments, the results were further verified by transcriptome analysis. The mouse infection model was established, and the inhibitory mechanism of kaempferol with ceftiofur on bacteria in vivo was further verified by HE staining and immunohistochemistry.

Results and discussion

Kaempferol with ceftiofur exerts synergistic antibacterial and bactericidal effects on ESBLs E. coli by influencing β-lactamase activity, biofilm formation, and LuxS/AI-2 QS system. In vivo, kaempferol protected the small intestinal villi from the damage of ESBLs E. coli. Furthermore, kaempferol fully restores the activity of ceftiofur in animal infection models by relieving the TLR4/NF-κb pathway. In conclusion, the sensitivity of ESBLs E. coli to ceftiofur in vitro and in vivo could be enhanced by kaempferol, which showed that kaempferol may be a kind of antibiotic adjuvant.

Bioassay-Guided Isolation and Identification of Antibacterial Compounds from Invasive Tree of Heaven Stem and Trunk Bark

Flash column chromatographic fractionation of tree of heaven (Ailanthus altissima) stem and trunk bark extracts, guided by thin-layer chromatography (TLC)-Bacillus subtilis assay and TLC-heated electrospray high-resolution tandem mass spectrometry (HESI-HRMS/MS), lead to the isolation of six known compounds: (9Z,11E)-13-hydroxy-9,11-octadecadienoic acid (13-HODE, A1), (10E,12Z)-9-hydroxy-10,12-octadecadienoic acid (9-HODE, A2), hexadecanedioic acid (thapsic acid, A3), 16-hydroxyhexadecanoic acid (juniperic acid, A4), 16-feruloyloxypalmitic acid (alpinagalanate, A5), and canthin-6-one (A6). Their structures were elucidated by HESI-HRMS/MS and one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. This is the first study identifying A1-A5 in A. altissima tree. Except for A5, all isolated compounds exhibited antibacterial activity against B. subtilis in microdilution assays. A6 showed the strongest effect with a minimum inhibitory concentration (MIC) value of 8.3 µg/mL. The antibacterial activity of A3 and A4 is newly described.

Microneedles Constructed by Swellable Hydrogels Loaded with Celastrol for Efficient Treatment of Skin Infections Induced by Drug-Resistant Bacterial Strains

The urgent need for new antimicrobial drugs arises from the limited efficacy of traditional antibiotics against emerging drug-resistant strains. Celastrol (CSL) demonstrates an exceptional antibacterial property that remains unaffected by bacterial resistance, but its poor water solubility limits its wide applications. This study uses the hydrophobic inner cavity of mono-(6-diethylenetriamine-6-deoxy)-β-cyclodextrin (mβ-CD) (a derivative of cyclodextrin) to encapsulate CSL, constructing an inclusion complex (CSL@mβ-CD) to enhance the water solubility of CSL. The obtained inclusion complex is further incorporated into a swellable hydrogel microneedle (MN) to obtain CSL@mβ-CD/MN. The fabricated CSL@mβ-CD/MN can enable the sustained release of CSL, achieving effective bacterial eradication at infected sites. In vivo experiments demonstrate that CSL@mβ-CD/MN has a remarkable efficacy in the treatment of methicillin-resistant Staphylococcus aureus-induced subcutaneous abscesses and wound infections. Specifically, CSL@mβ-CD/MN can effectively penetrate the stratum corneum of the skin to realize rapid elimination of the bacteria in wounds. Moreover, CSL@mβ-CD/MN can efficiently scavenge reactive oxygen species, promote M2 polarization of macrophages, and relieve local inflammation at the wound sites. These results reveal that CSL@mβ-CD/MN holds great promise in the clinical treatment of acute skin infections induced by drug-resistant bacteria.

Hypericum Perforatum Callus Extract-Loaded Composite Hydrogel with Diverse Bioactivities for Enhanced Wound Healing and Fibrosis Prevention

Plant Callus are a valuable source of pluripotent stem cells and bioactive phytochemicals. Meanwhile, the Hypericum perforatum callus extract (HPCE) is particularly rich in compounds such as hyperforin, hypericin, quercetin, and other phenolic and flavonoid derivatives. These phytochemicals exhibit strong antibacterial, antioxidant, anti-inflammatory, and anti-fibrotic properties, making them promising for wound healing. One of the most critical challenges following wound healing is the formation of fibrosis, which can compromise the complex structural integrity of skin. To address this issue, a poly(vinyl alcohol)/chitosan/alginate (PCA) wound dressing loaded with HPCE is developed. This hydrogel dressing features a porous structure with suitable mechanical properties and a high swelling capacity, potentially enhancing its effectiveness in promoting tissue regeneration and wound healing. In vitro studies have confirmed its biocompatibility, cell proliferation, and cell adhesion properties. Additionally, the dressing has demonstrated the ability to inhibit the proliferation of certain antibiotic-resistant bacteria. The in vivo studies revealed the anti-inflammatory properties, promotion of angiogenesis, facilitation of re-epithelialization, and stimulation of collagen deposition of the dressing under investigation. Moreover, the immunohistochemistry analysis of the two key markers, p16 and p53, has shown that the application of the dressing helps prevent fibrosis after wound healing.

Synthesis of arylated tetrahydrobenzo[H]quinoline-3-carbonitrile derivatives as potential hits for treatment of diabetes

Aim: Quinoline scaffolds are serving as the core structure for numerous antifungal, analgesic, antipyretic, anti-inflammatory drugs as well as have also been investigated for their potential antidiabetic properties. Though further exploration is required in this area as the current antidiabetic agents, such as acarbose, miglitol and voglibose, are associated with several adverse side effects. In this context, arylated tetrahydrobenzo[H]quinoline-3-carbonitrile derivatives were designed and evaluated as potential antidiabetic agents.Materials & methods: A one-pot multicomponent reaction of 6-methoxy-1-tetralone with ethyl cyanoacetate, ammonium acetate and varying aldehydes yielded a range of new arylated tetrahydrobenzo[h]quinoline-3-carbonitrile molecules 1-36.Results: Compounds 2-5, 12, 13, 19 and 32-34 showed excellent inhibition against α-amylase (IC50 = 3.42-15.14 μM) and α-glucosidase (IC50 = 0.65-9.23 μM) enzymes in comparison to the standard acarbose (IC50 = 14.35 μM). In addition, all compounds revealed significant to moderate DPPH radical scavenging activity (SC50 = 21.30-138.30 μM) compared with BHT (SC50 = 64.40 μM). Kinetic studies confirmed competitive inhibition mode, while molecular docking studies comprehend ligands' interaction with enzyme's active sites and absorption, distribution, metabolism, and excretion analysis confirms that all synthetic derivatives are nontoxic.Conclusion: This research offers a range of lead candidates to become antidiabetic agents after further advanced study.

An automatic LC-MS/MS data analysis workflow for herbal compound annotation with AutoAnnotatoR: A case study of ten botanical origins of Fritillaria species

BACKGROUND

Despite the widespread implementation of analytical hardware capable of recording large-scale datasets for botanical natural products, the data processing procedures for compound annotation remain a bothersome obstacle that demand a tremendous amount of time and expert knowledge.

METHODS

Herein, an automatic LC-MS/MS data analysis workflow with AutoAnnotatoR was introduced for the compound annotation of plant derived natural products, which has the merits of great efficiency, high accuracy, saving time and simplified process. This procedure enabled automatic matching of MS2 data with characteristic fragment ions, as well as MS1 data with compound libraries, which improves the accuracy of structural elucidation. Notably, the optimization of collision energy for each target ion was successfully performed for the first time, facilitating the acquisition of comprehensive fragmentation information.

RESULTS

The automatic analysis workflow with AutoAnnotatoR was successfully applied for the annotation of alkaloids from 10 botanical origins of Fritillaria species. Consequently, a total of 2684 chemical constituents were tentatively characterized, with 23 components being unambiguously validated by reference standards and 2434 being probable novel chemicals.

CONCLUSION

The entire data analysis procedure takes only a few hours, vastly improving analysis speed while assuring high accuracy. This method provides a powerful tool for the rapid and precise annotation of complex natural products. The workflow is publicly accessible on Github as an open-source R package called AutoAnnotatoR (https://github.com/anyaling2022/AutoAnnotatoR).

Plant-Derived Chinese Herbal Hydrogel Microneedle Patches for Wound Healing

Several natural Chinese herbal medicines have demonstrated considerable potential in facilitating wound healing, while the primary concern remains centered around optimizing formulation and structure to maximize their efficacy. To address this, a natural microneedles drug delivery system is proposed that harnesses gelatinized starch and key Chinese herbal ingredients-aloe vera and berberine. After gelatinized and aged in a well-designed mold, the starch-based microneedles are fabricated with suitable mechanical strength to load components. The resulting Chinese herbal hydrogel microneedles, enriched with integrated berberine and aloe, exhibit antibacterial, anti-inflammatory, and fibroblast growth-promoting properties, thereby facilitating wound healing in the whole process. In vivo experimental results underscore the notable achievements of the microneedles in early-stage antibacterial effects and subsequent tissue reconstruction, contributing significantly to the overall wound healing process. These results emphasize the advantageous combination of traditional Chinese medicine with microneedles, presenting a novel strategy for wound repair and opening new avenues for the application of traditional Chinese medicine.

Bactericidal and Synergistic Effects of Lippia origanoides Essential Oil and Its Main Constituents against Multidrug-Resistant Strains of Acinetobacter baumannii

Bacterial resistance in Acinetobacter baumannii is a significant public health challenge, as these bacteria can evade multiple antibiotics, leading to difficult-to-treat infections with high mortality rates. As part of the search for alternatives, essential oils from medicinal plants have shown promising antibacterial potential due to their diverse chemical constituents. This study evaluated the antibacterial, antibiofilm, and synergistic activities of the essential oil of Lippia origanoides (EOLo) and its main constituents against multidrug-resistant clinical isolates of A. baumannii. Additionally, the antibacterial and antibiofilm potential of a nanoemulsion containing carvacrol (NE-CAR) was assessed. EOLo was extracted through hydrodistillation, and its components were identified via gas chromatography coupled with mass spectrometry. The A. baumannii isolates (n = 9) were identified and tested for antimicrobial susceptibility using standard disk diffusion methods. Antibacterial activity was determined by broth microdilution, while antibiofilm activity was measured using colorimetric methods with crystal violet and scanning electron microscopy. Synergism tests with antibiotics (meropenem, ciprofloxacin, gentamicin, and ampicillin+sulbactam) were performed using the checkerboard method. The primary constituents of EOLo included carvacrol (48.44%), p-cymene (14.58%), and thymol (10.16%). EOLo, carvacrol, and thymol demonstrated significant antibacterial activity, with carvacrol showing the strongest effect. They were also effective in reducing biofilm formation, as was NE-CAR. The combinations with antibiotics revealed significant synergistic effects, lowering the minimum inhibitory concentration of the tested antibiotics. Therefore, this study confirms the notable antibacterial activity of the essential oil of L. origanoides and its constituents, especially carvacrol, suggesting its potential as a therapeutic alternative for A. baumannii infections.

Antimicrobial potential of Hippocratea Indica Willd. Acetone Leaf fractions against Salmonella Typhi: an in vitro and in silico study

Salmonella Typhi is a major global concern in many low- and middle-income countries. In addition, the emergence and persistence of drug resistant strains has increased the impact of this disease. Plant metabolites have been explored traditionally and scientifically as antimicrobial agents. Thus, this study was designed to investigate the antimicrobial potential of acetone leaf fractions of H. indica against S. Typhi. Dried pulverized leaves of H. indica were extracted using cold maceration with acetone after defatting with n-hexane. The leaf extract was concentrated and subjected to column chromatography and eight bioactive fractions were identified. The fractions were characterized using gas chromatography-mass spectrometry. The fractions were evaluated for antibacterial activity against Salmonella Typhi in-vitro and in-silico. The lowest MIC was observed in fractions 20 and 21 (0.375 mg/mL) while the lowest MBC was observed in all fractions except 7, 17 and 18 (0.375 mg/mL). A ligand from fraction 8 had the highest binding affinity to Type I dehydroquinase (-3.4) and a ligand from fraction 7 had the highest binding affinity to Gyrase B (-11.2). This study concludes that the overall antimicrobial activity of the acetone leaf extract of H. indica provided evidence that it contains drug-like compounds that can be further explored as a drug candidate against S. Typhi.

Antibacterial activity of structurally diverse natural prenylated isobavachalcone derivatives

Isobavachalcone (IBC) is a natural prenylated flavonoid containing chalcone and prenyl chain moieties with a wide range of biological and pharmacological properties. In this work, we synthesized structurally diversified derivatives (IBC-2 to IBC-10) from the natural prenylated chalcone IBC isolated from Psoralea corylifolia and assessed their antibacterial potency against the Gram-positive and Gram-negative bacterial strains S. aureus ATCC 29213, MRSA ATCC 15187, E. coli ATCC25922 and P. aeruginosa ATCC 27853. IBC and IBC-2 exhibited a minimum inhibition concentration (MIC) of 5.0 μM against S. aureus ATCC 29213, whereas IBC-3 exhibited a broad-spectrum activity against Gram-positive and Gram-negative pathogens. Cytotoxicity assessments on the murine RAW 264.7 macrophage cell line revealed minimal to moderate cytotoxicity for IBC-2 and IBC-3 with a favorable selectivity index (>10). Time- and concentration-dependent studies further supported the bactericidal nature of the compounds, as IBC, IBC-2, and IBC-3 exhibited concentration-dependent killing of S. aureus in a time-dependent manner. Furthermore, combination studies, SEM analysis, and PI staining suggest that IBC-3's mechanism of action targets the bacteria's cytoplasmic membrane or cell wall. The bioactive compounds displayed promising drug-like characteristics and a favorable pharmacokinetic profile (ADME-Tox), indicating a projected high oral bioavailability. Structure-activity relationships (SARs) drawn from this study reveal that a prenyl chain at the A-ring and hydroxy functional groups attached to the aromatic rings of chalcone scaffolds are responsible for this antibacterial potential, which will be helpful in the future discovery and development of antibiotics from natural products to overcome the antibiotic resistance crisis.

Recent Progress in Terrestrial Biota Derived Antibacterial Agents for Medical Applications

Conventional antibiotic and multidrug treatments are becoming less and less effective and the discovery of new effective and safe antibacterial agents is becoming a global priority. Returning to a natural antibacterial product is a relatively new current trend. Terrestrial biota is a rich source of biologically active substances whose antibacterial potential has not been fully utilized. The aim of this review is to present the current state-of-the-art terrestrial biota-derived antibacterial agents inspired by natural treatments. It summarizes the most important sources and newly identified or modified antibacterial agents and treatments from the last five years. It focuses on the significance of plant- animal- and bacteria-derived biologically active agents as powerful alternatives to antibiotics, as well as the advantages of utilizing natural antibacterial molecules alone or in combination with antibiotics. The main conclusion is that terrestrial biota-derived antibacterial products and substances open a variety of new ways for modern improved therapeutic strategies. New terrestrial sources of known antibacterial agents and new antibacterial agents from terrestrial biota were discovered during the last 5 years, which are under investigation together with some long-ago known but now experiencing their renaissance for the development of new medical treatments. The use of natural antibacterial peptides as well as combinational therapy by commercial antibiotics and natural products is outlined as the most promising method for treating bacterial infections. In vivo testing and clinical trials are necessary to reach clinical application.

The potentiality of isoflavones from Derris robusta (DC.) Benth. against α-glucosidase

The four recently described isoflavones, derrisrobustones A-D, and eight known isoflavones extracted from Derris robusta (DC.) Benth. (Leguminosae) were identified as potential isoflavones for α-glucosidase inhibitory activity. However, the inhibitory ability of each isoflavone was quite different and the structural and dynamical properties of the isoflavones in the binding with α-glucosidase have not been studied. In this study, the molecular dynamics (MD) simulation and the molecular mechanics generalized Born surface area (MM/GBSA) methods were applied to gain insight into isoflavones bound with the α-glucosidase active site. The results found that the isoflavones with a hydroxy substituent could be stabilized in the α-glucosidase active site with low values of the binding free energy, especially derrisrobustone D and derrubone. The isoflavones, except for derrubone, were bound with α-glucosidase by means of electrostatic force effectively.

Antivirulence and antipathogenic activity of Mayan herbal remedies against Pseudomonas aeruginosa

ETHNOPHARMACOLOGICAL RELEVANCE

The Yucatan Peninsula has a privileged wealth of vascular plants with which various Mayan herbal formulations have been developed. However, studies on their antipathogenic and antivirulence properties are scarce.

AIM OF THE STUDY

Identify antivirulence properties in Mayan herbal remedies and determine their antipathogenic capacity in burn wounds infected with Pseudomonas aeruginosa.

MATERIALS AND METHODS

An ethnobotanical study was conducted in Mayan communities in central and southern Quintana Roo, Mexico. Furthermore, the antipathogenic capacity of three Mayan herbal remedies was analyzed using an animal model of thermal damage and P. aeruginosa infection. Antivirulence properties were determined by inhibiting phenotypes regulated by quorum sensing (pyocyanin, biofilm, and swarming) and by the secretion of the ExoU toxin. The chemical composition of the most active herbal remedy was analyzed using molecular network analysis.

RESULTS

It was found that topical administration of the remedy called "herbal soap" (HS) for eleven days maintained 100% survival of the animals, reduced establishment of the bacteria in the burn and prevented its systemic dispersion. Although no curative effect was recorded on tissue damaged by HS treatment, its herbal composition strongly reduced swarming and ExoU secretion. Through analysis of Molecular Networks, it was possible to carry out a global study of its chemical components, and identify the family of oxindole monoterpenoid alkaloids and carboline and tetrahydropyrididole alkaloids. In addition, flavonols, flavan-3-ols, and quinic acid derivatives were detected.

CONCLUSIONS

The antipathogenic and antivirulence capacity of ancient Mayan remedies makes them a potential resource for developing new antibacterial therapies to treat burns infected by P. aeruginosa.

Development of amphipathic derivatives of thymol and carvacrol as potent broad-spectrum antibacterial agents

In the current study, to discover novel antibacterial agents, we designed and synthesized 72 carvacrol and thymol derivatives by biomimicking the structure and function of cationic antimicrobial peptides (AMPs). Many of the derivatives showed good antibacterial activity, and compound thy2I exhibited the most potent antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.5 μg/mL to 8 μg/mL. Compound thy2I could kill both gram-positive and gram-negative bacteria via a membrane-targeting mechanism of action with a low frequency of resistance. In addition, thy2I had the advantages of good membrane selectivity, low toxicity in vitro and in vivo, and good plasma stability. The in vivo activity results revealed that thy2I exhibited a positive therapeutic effect in a mouse skin abscess model induced by Staphylococcus aureus ATCC29213. After thy2I treatment (10 mg/kg), the bacterial load of the S. aureus-infected abscesses was reduced by approximately 99.65 %. Our study suggests that thy2I may serve as an antibacterial lead for further clinical evaluation.

In vitro and in silico studies of antibacterial activities of secofriedelane derivatives from Senna alata (L) Roxb

In this study, six compounds were obtained from a methanolic extract of air-dried leaves of Senna alata and one of them, a triterpenoid (secofriedelane) named as 7-(2-carboxyethyl)-3, 4b, 6a, 8, 10a, 12a-hexamethyl-8-vinyloctadecahydrochrysene-3-carboxylic acid (5) was isolated for the first time from this plant. Then, its chemical structure was detailed and characterised by FT-IR, 1H and 13C- NMR and ESI-MS. Besides, two chemical-modified derivatives of secofriedelane (5a, 5b) were synthesised by methylation and allylation reactions, respectively, and their in vitro antibacterial activities were also evaluated. The results revealed that all the triterpenes showed, against gram-positive and -negative bacterial strains, good and moderate antibacterial activities with bactericidal effects that were enhanced by the methyl groups and altered with the allyl ones. Moreover, the molecular docking results of 5, 5a and 5b in the DNA gyrase (2XCT) active site showed that triterpene 5 has a good score very close to reference (ciprofloxacin).

Activity-based protein profiling in drug/pesticide discovery: Recent advances in target identification of antibacterial compounds

Given the escalating incidence of bacterial diseases and the challenge posed by pathogenic bacterial resistance, it is imperative to identify appropriate methodologies for conducting proteomic investigations on bacteria, and thereby promoting the target-based drug/pesticide discovery. Interestingly, a novel technology termed "activity-based protein profiling" (ABPP) has been developed to identify the target proteins of active molecules. However, few studies have summarized advancements in ABPP for identifying the target proteins in antibacterial-active compounds. In order to accelerate the discovery and development of new drug/agrochemical discovery, we provide a concise overview of ABPP and its recent applications in antibacterial agent discovery. Diversiform cases were cited to demonstrate the potential of ABPP for target identification though highlighting the design strategies and summarizing the reported target protein of antibacterial compounds. Overall, this review is an excellent reference for probe design towards antibacterial compounds, and offers a new perspective of ABPP in bactericide development.

Three New Ent-Kaurane Diterpenes with Antibacterial Activity from Sigesbeckia orientalis

Three novel ent-kaurane diterpenes, namely sigesbeckin A-C (1-3), in conjunction with eight previously identified analogues (4-11), were isolated from Sigesbeckia orientalis. Their chemical structures were resolved through multiple spectroscopic analyses. All compounds were assessed for antimicrobial bioactivity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) strains. In particular, compounds 1 and 5 demonstrated moderate efficacy, with MIC values of 64 μg/mL. Moreover, compounds 3, 5, and 11 were found to synergize with doxorubicin hydrochloride (DOX) and vancomycin (VAN) against MRSA and VRE. The aforementioned findings offer valuable insights for the development of novel alternatives to antibiotics, which can effectively tackle the escalating issue of antibiotic resistance.

Alkyl Pyridinol Compounds Exhibit Antimicrobial Effects against Gram-Positive Bacteria

Background/Objectives. The rise of antibiotic-resistant pathogens represents a significant global challenge in infectious disease control, which is amplified by the decline in the discovery of novel antibiotics. Staphylococcus aureus continues to be a highly significant pathogen, causing infections in multiple organs and tissues in both healthcare institutions and community settings. The bacterium has become increasingly resistant to all available antibiotics. Consequently, there is an urgent need for novel small molecules that inhibit the growth or impair the survival of bacterial pathogens. Given their large structural and chemical diversity, as well as often unique mechanisms of action, natural products represent an excellent avenue for the discovery and development of novel antimicrobial treatments. Anaephene A and B are two such naturally occurring compounds with significant antimicrobial activity against Gram-positive bacteria. Here, we report the rapid syntheses and biological characterization of five novel anaephene derivatives, which display low cytotoxicity against mammalian cells but potent antibacterial activity against various S. aureus strains, including methicillin-resistant S. aureus (MRSA) and the multi-drug-resistant community-acquired strain USA300LAC. Methods. A Sonogashira cross-coupling reaction served as the key step for the synthesis of the alkyl pyridinol products. Results/Conclusions. Using the compound JC-01-074, which displays bactericidal activity already at low concentrations (MIC: 16 μg/mL), we provide evidence that alkyl pyridinols target actively growing and biofilm-forming cells and show that these compounds cause disruption and deformation of the staphylococcal membrane, indicating a membrane-associated mechanism of action.

Exploring Synergistic Inhibition of Inflammatory and Antioxidant Potential: Integrated In Silico and In Vitro Analyses of Garcinia mangostana, Curcuma comosa, and Acanthus ebracteatus

Compared with the use of a single herb alone, herb combinations can significantly increase their effectiveness in treating various diseases. The objective of this research was to determine the appropriate proportions of Garcinia mangostana (GM), Curcuma comosa (CC), and Acanthus ebracteatus (AE) to enhance their antioxidant and anti-inflammatory properties. The study employed computer modeling (in silico) and laboratory testing (in vitro). The optimal levels of phenolic and flavonoid compounds were achieved with a ratio of 15 parts GM, 5 parts CC, and 10 parts AE. In contrast, the 10 : 15 : 5 ratio resulted in the highest antioxidant activity, reducing DPPH radicals by 80.33% and ABTS radicals by 92.20%. The ratio had a synergistic effect and was within the safe range, ranging from 82.97 to 147.04 µg/mL. The ratio of 5 : 10 : 15 had the greatest anti-inflammatory effects, with an exceptional activity level of 98.86%. It effectively suppressed 23 genes or proteins, including the prominent NFE2L2 gene, and had a synergistic effect. This combination effectively inhibits inflammation (IC50: 12.05 µg/mL) and is safe for macrophages at concentrations up to 50 µg/mL. These findings emphasize the potential of these herbal mixtures for antioxidant and anti-inflammatory applications.

Hyaluronic Acid-Modified Micelles of Azithromycin and Quercetin Against Infections Caused by Methicillin-Resistant Staphylococcus Aureus

Introduction

Resistance of intracellular pathogens is a challenge in microbial therapy. Methicillin-resistant Staphylococcus aureus (MRSA), which is able to persist inside the cells of infected tissues, is protected from attack by the immune system and many antimicrobial agents. To overcome these limitations, nano-delivery systems can be used for targeted therapy of intracellular MRSA.

Methods

Hyaluronic acid-modified azithromycin/quercetin micelles (HA-AZI/Qe-M) were synthesized by thin film hydration. The micelles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR), and the drug loading (DL) and encapsulation efficiency (EE) were detected by high performance liquid chromatography (HPLC). The uptake ability of RAW264.7 cells was investigated, and its distribution in mice was evaluated by in vivo imaging. The inhibitory effect of the micelles against MRSA in vitro and its ability to eliminate intracellular bacteria were evaluated. Bacterial muscle-infected mice were constructed to evaluate the therapeutic effect of the micelles on bacterial infections in vivo and the biocompatibility of the micelles was investigated.

Results

HA-AZI/Qe-M had suitable physical and chemical properties and characterization. In vitro antibacterial experiments showed that HA-AZI/Qe-M could effectively inhibit the growth of MRSA, inhibit and eliminate the biofilm formed by MRSA, and have an excellent therapeutic effect on intracellular bacterial infection. The results of RAW264.7 cells uptake and in vivo imaging showed that HA-AZI/Qe-M could increase the cellular uptake, target the infection site, and prolong the treatment time. The results of in vivo antibacterial infection experiments showed that HA-AZI/Qe-M was able to ameliorate the extent of thigh muscle infections in mice and reduce the expression of inflammatory factors.

Conclusion

HA-AZI/Qe-M is a novel and effective nano-drug delivery system that can target intracellular bacterial infection, and it is expected to be safely used for the treatment of MRSA infection.

Predicting of novel homoserine dehydrogenase inhibitors against Paracoccidioides brasiliensis: integrating in silico and in vitro approaches

Aim: To search for potential inhibitors to homoserine dehydrogenase (HSD) in Paracoccidioides brasiliensis the causative agent of paracoccidioidomycosis, an infection with a high mortality rate in Brazil.Materials & methods: The enzyme was modeled and used in the virtual screening of the compounds. The library was first screened by the Autodock, in which 66 molecules were better ranked than substrate, and then, also evaluated by the Molegro and Gold programs.Results: The HS23 and HS87 molecules were selected in common by the three programs, and ADME/Tox evaluation indicates they are not toxic. The molecular dynamics of PbHSD bonded to ligands showed stable complexes until 50 ns. To validate the results, compounds were purchased for assays of minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), synergic profile with Amphotericin B (AmB) and cytotoxicity. The two molecules presented MIC of 32 μg/ml and MFC of 64 μg/ml against the P. brasiliensis (strain Pb18). They also showed synergistic activity with AmB and a lack of toxicity against Hela and Vero cell lines.Conclusion: These results suggest that the HS23 and HS87 are promising candidates as PbHSD inhibitors and may be used as hits for the development of new drugs against paracoccidioidomycosis.

Discovery of new quaternized norharmane dimers as potential anti-MRSA agents

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA)-caused infections greatly threaten public health. The discovery of natural-product-based anti-MRSA agents for treating infectious diseases has become one of the current research focuses.

OBJECTIVES

This study aims to identify promising anti-MRSA agents with a clear mechanism based on natural norharmane modified by quaternization or dimerization.

METHODS

A total of 32 norharmane analogues were prepared and characterized. Their antibacterial activities and resistance development propensity were tested by the broth double-dilution method. Cell counting kit-8 and hemolysis experiments were used to assess their biosafety. The plasma stability, bactericidal mode, and biofilm disruption effects were examined by colony counting and crystal violet staining assays. Fluorescence microscopy, metabolomic analysis, docking simulation and spectra titration revealed its anti-MRSA mechanisms. The mouse skin infection model was used to investigate the in vivo efficacy.

RESULTS

Compound 5a was selected as a potential anti-MRSA agent, which exhibited potent anti-MRSA activity in vitro and in vivo, low cytotoxicity and hemolysis under an effective dose. Moreover, compound 5a showed good stability in 50% plasma, a low tendency of resistance development and capabilities to disrupt bacterial biofilms. The mechanism studies revealed that compound 5a could inhibit the biosynthesis of bacteria cell walls, damage the membrane, disturb energy metabolism and amino acid metabolism pathways, and interfere with protein synthesis and nucleic acid function.

CONCLUSIONS

These results suggested that compound 5a is a promising candidate for combating MRSA infections, providing valuable information for further exploiting a new generation of therapeutic antibiotics.

Antibacterial Activity of Plants in Cirsium: A Comprehensive Review

As ethnic medicine, the whole grass of plants in Cirsium was used as antimicrobial. This review focuses on the antimicrobial activity of plants in Cirsium, including antimicrobial components, against different types of microbes and bacteriostatic mechanism. The results showed that the main antimicrobial activity components in Cirsium plants were flavonoids, triterpenoids and phenolic acids, and the antimicrobial ability varied according to the species and the content of chemicals. Among them, phenolic acids showed a strong antibacterial ability against Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococcus faecium. The antibacterial mechanisms include: (1) damaging the cell membrane, cell walls, mitochondria and nucleus of bacteria; (2) inhibiting the synthesis of proteins and nucleic acids; (3) suppressing the synthesis of enzymes for tricarboxylic acid cycle pathways and glycolysis, and then killing the bacteria via inhibition of energy production. Totally, most research results on antimicrobial activity of Cirsium plants are reported based on in vitro assays. The evidence from clinical data and comprehensive evaluation are needed.

Application of natural-products repurposing strategy to discover novel FtsZ inhibitors: Bactericidal evaluation and the structure-activity relationship of sanguinarine and its analogs

The novel bactericidal target-filamentous temperature-sensitive protein Z (FtsZ)-has drawn the attention of pharmacologists to address the emerging issues with drug/pesticide resistance caused by pathogenic bacteria. To enrich the structural diversity of FtsZ inhibitors, the antibacterial activity and structure-activity relationship (SAR) of natural sanguinarine and its analogs were investigated by using natural-products repurposing strategy. Notably, sanguinarine and chelerythrine exerted potent anti-Xanthomonas oryzae pv. oryzae (Xoo) activity, with EC50 values of 0.96 and 0.93 mg L-1, respectively, among these molecules. Furthermore, these two compounds could inhibit the GTPase activity of XooFtsZ, with IC50 values of 241.49 μM and 283.14 μM, respectively. An array of bioassays including transmission electron microscopy (TEM), fluorescence titration, and Fourier transform infrared spectroscopy (FT-IR) co-verified that sanguinarine and chelerythrine were potential XooFtsZ inhibitors that could interfere with the assembly of FtsZ filaments by inhibiting the GTPase hydrolytic ability of XooFtsZ protein. Additionally, the pot experiment suggested that chelerythrine and sanguinarine demonstrated excellent curative activity with values of 59.52% and 54.76%, respectively. Excitedly, these two natural compounds also showed outstanding druggability, validated by acceptable drug-like properties and low toxicity on rice. Overall, the results suggested that chelerythrine was a new and potential XooFtsZ inhibitor to develop new bactericide and provided important guiding values for rational drug design of FtsZ inhibitors. Notably, our findings provide a novel strategy to discover novel, promising and green bacterial compounds for the management of plant bacterial diseases.

Deep learning-assisted flavonoid-based fluorescent sensor array for the nondestructive detection of meat freshness

Gas sensors containing indicators have been widely used in meat freshness testing. However, concerns about the toxicity of indicators have prevented their commercialization. Here, we prepared three fluorescent sensors by complexing each flavonoid (fisetin, puerarin, daidzein) with a flexible film, forming a fluorescent sensor array. The fluorescent sensor array was used as a freshness indication label for packaged meat. Then, the images of the indication labels on the packaged meat under different freshness levels were collected by smartphones. A deep convolutional neural network (DCNN) model was built using the collected indicator label images and freshness labels as the dataset. Finally, the model was used to detect the freshness of meat samples, and the overall accuracy of the prediction model was as high as 97.1%. Unlike the TVB-N measurement, this method provides a nondestructive, real-time measurement of meat freshness.

Self-Assembled Borneol-Guanidine-Based Amphiphilic Polymers as an Efficient Antibiofilm Agent

Biofilm-associated infections remain a tremendous obstacle to the treatment of microbial infections globally. However, the poor penetrability to a dense extracellular polymeric substance matrix of traditional antibacterial agents limits their antibiofilm activity. Here, we show that nanoaggregates formed by self-assembly of amphiphilic borneol-guanidine-based cationic polymers (BGNx-n) possess strong antibacterial activity and can eliminate mature Staphylococcus aureus (S. aureus) biofilms. The introduction of the guanidine moiety improves the hydrophilicity and membrane penetrability of BGNx-n. The self-assembled nanoaggregates with highly localized positive charges are expected to enhance their interaction with negatively charged bacteria and biofilms. Furthermore, nanoaggregates dissociate on the surface of biofilms into smaller BGNx-n polymers, which enhances their ability to penetrate biofilms. BGNx-n nanoaggregates that exhibit superior antibacterial activity have the minimum inhibitory concentration (MIC) of 62.5 μg·mL-1 against S. aureus and eradicate mature biofilms at 4 × MIC with negligible hemolysis. Taken together, this size-variable self-assembly system offers a promising strategy for the development of effective antibiofilm agents.

Medicinal Use of Chicory (Cichorium intybus L.)

The aim of this review is to discuss the numerous health-promoting properties of Cichorium intybus L. and bring together a range of publications to broaden knowledge and encourage further research and consideration of the plant use as treatment for a range of conditions. A comprehensive search of articles in Polish and English from 1986–2022 years was carried out in PubMed, Google Scholar and ScienceDirect using the keywords chicory, Cichorium intybus L., sesquiterpene lactones and their synonyms. Articles were checked for titles, abstracts, and full-text reviews. The first part of the review article discusses chicory, the countries in which it is found, its life cycle or modern cultivation methods, as well as its many uses, which will be discussed in more detail later in the article. The increased interest in plants as medicines or supplements is also briefly mentioned, as well as some limits that are associated with the medical use of plants. In the Results and Discussion section, there is a discussion of the numerous health-promoting properties of Cichorium intybus L. as a whole plant, with its collection of all the components, and we then examine the structure and the individual constituents of Cichorium intybus L. Among these, this article discusses those that can be utilized for causal applications in medicine, including sesquiterpene lactones and polyphenols, mainly known for their anti-cancer properties, although, in this article, their other health-promoting properties are also discussed. The article also examines inulin, a major component of Cichorium intybus L. The Discussion and the Conclusions sections propose directions for more detailed research and the range of factors that may affect specific results, which may have safety implications when used as supplements or medications.