Synthetic Antibiotics Research Articles

Advances in the Synthesis and Biological Applications of Enoxacin-Based Compounds

A comprehensive review of advances in the synthesis and biological applications of enoxacin (1, referred to as ENX)-based compounds is presented. ENX, a second-generation fluoroquinolone (FQ), is a prominent 1,8-naphthyridine containing compounds studied in medicinal chemistry. Quinolones, a class of synthetic antibiotics, are crucial building blocks for designing multi-biological libraries due to their inhibitory properties against DNA replication. Chemical modifications at positions 3 and 7 of the quinolone structure can transform antibacterial FQs into anticancer analogs. ENX and its derivatives have been examined for various therapeutic applications, including anticancer, antiviral, and potential treatment against COVID-19. Several synthetic methodologies have been devised for the efficient and versatile synthesis of ENX and its derivatives. This review emphasizes all-inclusive developments in the synthesis of ENX derivatives, focusing on modifications at C3 (carboxylic acid, Part A), C7 (piperazinyl, Part B), and other modifications (Parts A and B). The reactions considered were chosen based on their reproducibility, ease of execution, accessibility, and the availability of the methodology reported in the literature. This review provides valuable insights into the medicinal properties of these compounds, highlighting their potential as therapeutic agents in various fields.

Formulation and Optimization of Solid Lipid Nanoparticle-based Gel for Dermal Delivery of Linezolid Using Taguchi Design.

Linezolid (LNZ) is a synthetic oxazolidinone antibiotic approved for the treatment of uncomplicated and complicated skin and soft tissue infections caused by gram-positive bacteria. Typically, LNZ is administered orally or intravenously in most cases. However, prolonged therapy is associated with various side effects and life threatening complications. Cutaneous application of LNZ will assist in reducing the dose, hence minimizing the unwanted side/adverse effects associated with oral administration. Dermal delivery provides an alternative route of administration, facilitating a local and sustained concentration of the antimicrobial at the site of infection. The current research work aimed to formulate solid lipid nanoparticles (SLNs) based gel for dermal delivery of LNZ in the management of uncomplicated skin and soft tissue infections to maximise its benefits and minimise the side effects. SLNs were prepared by high-shear homogenisation and ultrasound method using Dynasan 114 as solid lipid and Pluronic F-68 as surfactant. The effect of surfactant concentration, drug-to-lipid ratio, and sonication time was investigated on particle size, zeta potential, and entrapment efficiency using the Taguchi design. The main effect plot of means and signal-to-noise ratio were generated to determine the optimized formulation. The optimized batch was formulated into a gel, and ex-vivo permeation study, in-vitro and in-vivo antibacterial activity were conducted. The optimised process parameters to achieve results were 2% surfactant concentration, a drug-to-lipid ratio of 1:2, and 360 s of sonication time. The optimized batch was 206.3± 0.17nm in size with a surface charge of -24.4± 4.67mV and entrapment efficiency of 80.90 ± 0.45%. SLN-based gel demonstrated anomalous transport with an 85.43% in vitro drug release. The gel showed a 5 cm zone of inhibition while evaluated for in vitro antibacterial activity against Staphylococcus aureus. Ex-vivo skin permeation studies demonstrated 20.308% drug permeation and 54.96% cutaneous deposition. In-vivo results showed a significant reduction in colony-forming units in the group treated with LNZ SLN-based gel. Ex-vivo studies ascertain the presence of the drug at the desired site and improve therapy. In-vivo results demonstrated the ability of SLN-based gel to significantly reduce the number of bacteria in the stripped infection model. The utilization of SLN as an LNZ carrier holds significant promise in dermal delivery.

Anticoccidial activities of Piper betle L essential oil on Eimeria tenella oocysts

Coccidiosis poses a significant threat to the poultry industry, with synthetic antibiotics and disinfectants being the primary tools for control. This study investigated the potential of Piper betle L essential oil (PBEO) as a natural alternative against Eimeria tenella, one of the most pathogenic Eimeria species affecting poultry. Our findings revealed that PBEO exhibits significant anticoccidial effects through two primary mechanisms: (i) oocysticidal activity by disintegrating oocyst walls and (ii) inhibition of the sporulation process. PBEO demonstrated oocysticidal activities ranging from 8.67 to 95.33% across concentrations from 0.04 to 40%. Notably, at 72 h post-incubation, a 0.04% PBEO concentration significantly reduced the number of sporulated oocysts (P ≤ 0.05) to 71.67%, showing effects comparable to those of formalin. PBEO reduced 50% of oocyst sporulation (IC50) in the concentration of 1.31% at 72 h. Gas chromatography-mass spectrometry (GC-MS) identified the primary constituents of PBEO, including eugenol, beta-caryophyllene, and other key compounds, collectively constituting 96% of the oil. This research underscores the potential of PBEO as a natural anticoccidial agent and lays the groundwork for further studies aimed at identifying, isolating, and developing active compounds that may specifically target the sporogony process in coccidian parasites.

Antibiotics in broilers chicken production: a review of impacts, challenges and potential alternatives

Globally, the use of antibiotic in animal industry was well known in the 20th century. Antibiotics usage as therapeutic and subtherapeutic means of improving growth and feed efficiency in livestock was well documented in literature. However, continuous use of antibiotics in food animals for increased growth and disease prevention has resulted in the development of antibiotic resistant bacteria in animals. This has led to disease treatment failure in the affected animals. The problem of transmission of antibiotic resistant bacteria to human through food chain and contamination of environment is another challenge of antibiotic usage in poultry production. Hence, the ban was placed on antibiotic usage in animal production. The restriction to the use of animal growth promoting antibiotic has gained high compliance in the developed countries. However, in the third world countries, this is still a battle that is on-going. To achieve the 2023 Global Action Plan on Antimicrobial Resistance goal, a lot is still left to be done. This review synthesized information on implications of antibiotics use on broiler chickens’ production cost efficiency and profitability; impact of antibiotics mode of action, diseases prevention and treatments of infection in broiler chickens’ production; challenges of antibiotics residual effect on meat quality and safety and alternatives to synthetic antibiotic for broiler chickens’ production.

Simultaneous Determination of Sulfamethoxazole and Trimethoprim from Clinical Urine and Blood Serum Samples by the Application of Poly(Cu2P4BCL4)/GCE.

Synthetic antibiotics known as sulfonamides suppress the synthesis of tetrahydrofolic acid, which cures respiratory tract infections and protozoal infections by preventing the creation of dihydrofolic acid. Electrochemical sensors based on tetrakis(1,10-phenanthroline)-μ-(4,4'-bipyridine) dicopper(II) chloride monohydrate ([P2Cu-Bip-CuP2]Cl4·H2O or simply Cu2P4BCl4) have been successfully applied for the determination of sulfamethoxazole (SMX) and trimethoprim (TMP) from samples. The experimental conditions and parameters were optimized to achieve the best electrode performances for simultaneous quantification of SMX and TMP. Based on the analysis of the effect of scan rate on the peak parameters, the R 2 for the peak current vs square root of the scan rate was greater than that of the peak current vs scan rate, indicating diffusion-controlled behavior of both species. The current intensities of both SMX and TMP were highly improved due to surface activation of the electrodes by electropolymerization. For SMX, the limit of detection was determined to be 27.94 nM, while for TMP, it was 21.56 nM, and the limit of quantifications was 71.88 nM, and the corresponding relative standard deviation for each was 0.74% and 0.11%. The constructed electrode was stored for varying durations ranging from two h to 2 days, and it was found to be above 97% stable after storing for 15 days. The real applicability of the suggested sensor for the simultaneous determination of SMX and TMP was verified by sensing clinical serum and urine samples and their spike recovery studies.

Monitoring concentration of quinolones in human serum by fluorescence and colorimetric analysis based on red carbon dots

Bacterial infections are common and predominant concern after surgical operation despite surgical techniques have improved significantly. Monitoring of antibiotics concentration can provide critical feedback in clinical treatment so as to achieve rapid and effective treatment and avoid bacterial resistance. Quinolones (QNs) are synthetic broad-spectrum antibiotics to treat bacterial infections. In this work, we developed a high-yield (50.67 %) red-emitting carbon dots (R-CDs) as fluorescence probe for sensing of three quinolone antibiotics, ofloxacin (OFL), gatifloxacin (GAT), and ciprofloxacin (CIP). R-CDs were prepared in 30 min using tartaric acid and o-phenylenediamine as precursors via an economical and efficient microwave-assisted method. At excitation of 339 nm, R-CDs show sensing performance towards OFL, GAT, CIP. Ofloxacin can be detected in the range of 0.25–30 μM with limit of detection (LOD) of 27.01 nM. Detection concentration range of gatifloxacin is between 0.25–40 μM and LOD is 23.73 nM. Ciprofloxacin can be detected in the range of 0.75–35 μM with LOD of 75.23 nM. A smartphone-assisted analysis platform was developed based on colorimetric phenomenon which applicable in three quinolones concentration monitoring in human serum. This research setup an efficient and promising therapeutic drug monitoring method for clinical treatment and widen the applications of carbon dots.

Exploration of the Antibacterial Potential from Rice Eel Skin Mucus (Monopterus albus) Against Bacteria Aeromonas hydrophila, Escherichia coli, and Staphylococcus aureus

The skin mucus of the rice eel (Monopterus albus) contains various antibacterial compounds and has the potential as a synthetic antibiotic. This research was conducted to explore the potential antibacterial power of the rice eel skin mucus against some pathogenic bacteria in freshwater fish. The bacteria were isolated from five samples of rice eel cultivation ponds belonging to Mr. Sabwan and then challenged with the mucus of the eel's skin through diffusion tests using paper discs. The rice eel skin mucus tested its antibacterial activity against three species of freshwater bacteria, Aeromonas hydrophila, Escherichia coli, and Staphylococcus aureus, by testing sensitivity and inhibitory zones. The inhibitory zones of each bacterium were measured using Vernier caliper which refers to the standardization of the inhibitory zone: < 4 mm no activity, 5-9 mm weak, 10- 14 mm medium, and > 15 mm strong. Test results showed that the eels' skin mucus could inhibit the growth of bacteria Aeromonas hydrophila, Escherichia coli, and Staphylococcus aureus.

Progress in the Study of Natural Antimicrobial Active Substances in Pseudomonas aeruginosa.

The prevalence of antimicrobial resistance reduces the effectiveness of antimicrobial drugs in the prevention and treatment of infectious diseases caused by pathogens such as bacteria, fungi, and viruses. Microbial secondary metabolites have been recognized as important sources for new drug discovery and development, yielding a wide range of structurally novel and functionally diverse antimicrobial drugs for the treatment of a variety of diseases that are considered good producers of novel antimicrobial drugs. Bacteria produce a wide variety of antimicrobial compounds, and thus, antibiotics derived from natural products still dominate over purely synthetic antibiotics among the antimicrobial drugs developed and introduced over the last four decades. Among them, Pseudomonas aeruginosa secondary metabolites constitute a richly diverse source of antimicrobial substances with good antimicrobial activity. Therefore, they are regarded as an outstanding resource for finding novel bioactive compounds. The exploration of antimicrobial compounds among Pseudomonas aeruginosa metabolites plays an important role in drug development and biomedical research. Reports on the secondary metabolites of Pseudomonas aeruginosa, many of which are of pharmacological importance, hold great promise for the development of effective antimicrobial drugs against microbial infections by drug-resistant pathogens. In this review, we attempt to summarize published articles from the last twenty-five years (2000-2024) on antimicrobial secondary metabolites from Pseudomonas aeruginosa.

Detection of Sulfonamide Antibiotics Using an Elastic Hydrogel Microparticles-Based Optical Biosensor.

Sulfonamide antibiotics were the first synthetic antibiotics on the market and still have a broad field of application. Their extensive usage, wrong disposal, and limited degradation technologies in wastewater treatment plants lead to high concentrations in the environment, resulting in a negative impact on ecosystems and an acceleration of antibiotic resistance. Although lab-based analytical methods allow for sulfonamide detection, comprehensive monitoring is hampered by the nonavailability of on-site, inexpensive sensing technologies. In this work, we exploit functionalized elastic hydrogel microparticles and their ability to easily deform upon specific binding with enzyme-coated surfaces to establish the groundwork of a biosensing assay for the fast and straightforward detection of sulfonamide antibiotics. The detection assay is based on sulfamethoxazole-functionalized hydrogel microparticles as sensor probes and the biomimetic interaction of sulfonamide analytes with their natural target enzyme, dihydropteroate synthase (DHPS). DHPS from S. pneumoniae was recombinantly produced by E. coli and covalently coupled on a glass biochip using a reactive maleic anhydride copolymer coating. Monodisperse poly(ethylene glycol) hydrogel microparticles of 50 μm in diameter were synthesized within a microfluidic setup, followed by the oriented coupling of a sulfamethoxazole derivative to the microparticle surface. In proof-of-concept experiments, sulfamethoxazole, as the most used sulfonamide antibiotic in medical applications, was demonstrated to be specifically detectable above a concentration of 10 μM. With its straightforward detection principle, this assay has the potential to be used for point-of-use monitoring of sulfonamide antibiotic contaminants in the environment.

Natural agents derived Pickering emulsion enabled by silica nanoparticles with enhanced antibacterial activity against drug-resistant bacteria

The emergence of antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) has become a global health challenge due to the overuse of antibiotics. Natural substances including enzymes and essential oils have shown great potential as alternative treatment options. However, the combinational use of these natural agents remains challenging due to the denaturation of enzymes upon direct contact with oil. In this study, we report the design of a Pickering emulsion containing two natural antibacterial agents, lysozyme and tea tree oil, stabilized by fractal silica nanoparticles. In this design, the enzyme activity is kept and the volatility problem of tea tree oil is mitigated. Due to synergistic bacterial cell wall digestion and membrane disruption functions, potent bactericidal efficacy in vitro against drug-resistant bacteria is achieved. The therapeutic potential is further demonstrated in a wound healing model with drug-resistant bacteria infection, better than a synthetic antibiotic, Ampicillin. This study opens new avenues for the development of natural product-based antimicrobial treatments with promising application potential.

Treatment of avian pathogenic Escherichia coli infected broilers with aqueous extracts of Vernonia amygdalina in a challenge experiment

Colibacillosis, which is the leading cause of infectious diseases resulting in mortality and economic losses in poultry is triggered by Avian pathogenic Escherichia coli (APEC). Conventionally, antibiotic growth promoters (AGP) are incorporated into poultry diets to control infectious diseases and boost performance. However, because of the problem of antimicrobial resistance, synthetic antibiotics are now restricted or banned in animal production in some countries. In this study, we carried out a challenge experiment by inoculating healthy broilers with APEC (106 cfu/mL) by oral gavage on day 21 of the experiment and orally administering various treatments five days post challenge for five days; synthetic antibiotics (T2), Vernonia amygdalina (bitter leaf) extracts (T3), no treatment (T4), which were compared with the control that wasn’t challenged (T1). The experiment lasted for 42 days. Performance, hematological and histological studies were carried out. The results show that the challenged birds became diseased with the development of visible lesions, which ameliorated over time to varying extents with the use of synthetic antibiotics and Vernonia treatments. Overall, the performance of the birds with the use of Vernonia (T3) was comparable with that of synthetic antibiotics (T2) without eliciting any adverse hematological effects on the broilers. We therefore conclude that Vernonia can be safely used as a supplement for disease prevention in broiler chicken production

An Antibiotic-Degrading Engineered Biofilm Platform to Combat Environmental Antibiotic Resistance.

The presence of antibiotics in natural water bodies is a growing problem regarding the occurrence of antibiotic resistance among various species. This is mainly caused by the excessive use of medical and veterinary antibiotics as well as the lack of effective treatment processes for eliminating residual antibiotics from wastewaters. In this study, we introduce a genetically engineered biomaterial as a solution for the effective degradation of one of the dominantly found antibiotics in natural water bodies. Our biomaterial harnesses laccase-type enzymes, which are known to attack specific types of antibiotics, i.e., fluoroquinolone-type synthetic antibiotics, and as a result degradation occurs. The engineered biomaterial is built using Escherichia coli biofilm protein CsgA as a scaffold, which is fused separately to two different laccase enzymes with the SpyTag-SpyCatcher peptide-protein duo. The designed biofilm materials were successful in degrading ciprofloxacin, as demonstrated with the data obtained from mass spectrometry analysis and cell viability assays.

Antibiotic intermediates and antibiotics synergistically promote the development of multiple antibiotic resistance in antibiotic production wastewater

Antibiotic resistance (AR) is a major public health concern. Antibiotic intermediates (AIs) used in the production of semisynthetic antibiotics have the same bioactive structure as parent antibiotics and synthetic antibiotic production wastewater usually contains high concentrations of residual AIs; however, the effects of AIs and their interactive effects with antibiotics on the emergence of AR are unknown. In this study, antibiotic-sensitive E. coli K12 was exposed to five types of β-lactam AIs and their parent antibiotic ampicillin to analyze their impact on the evolution of multiple AR. The results indicated that AI 6-APA inhibits bacterial growth and stimulates the production of reactive oxygen species, as well as induces AR and antibiotic persistence like the parent antibiotic AMP. Combined exposure to 6-APA and AMP synergistically stimulated the induction of multiple AR and antibiotic persistence. The resistance mutation frequency increased up to 6.1 × 106-fold under combined exposure and the combination index reached 1326.5, indicating a strong synergy of 6-APA and AMP. Phenotypic and genotypic analyses revealed that these effects were associated with the overproduction of reactive oxygen species, enhanced stress response signatures, and activation of efflux pumps. These findings provide evidence and mechanistic insights into AR induction by AIs in antibiotic production wastewater.

Biological effects of Bougainvillea glabra, Delonix regia, Lantana camara, and Platycladus orientalis extracts and their possible metabolomics therapeutics against the West Nile virus vector, Culex pipiens (Diptera: Culicidae)

Plants are a treasure trove of biological materials containing a wide range of potential phytochemicals that are target-specific, rapidly biodegradable, and environmentally friendly, with multiple medicinal effects. Unfortunately, the development of resistance to synthetic pesticides and antibiotics led to the discovery of new antibiotics, antioxidants, and biopesticides. This has also led to the creation of new medications that work very well. The current study aimed to prove that ornamental plants contain specialized active substances that are used in several biological processes. Mosquitoes, one of the deadliest animals on the planet, cause millions of fatalities each year by transmitting several human illnesses. Phytochemicals are possible biological agents for controlling pests that are harmful. The potential of leaf extracts of Bougainvillea glabra, Delonix regia, Lantana camara, and Platycladus orientalis against Culex pipiens and microbial agents was evaluated. Acetone extracts had more toxic effects against Cx. pipiens larvae (99.0–100 %, 72 h post-treatment), and the LC50 values were 142.8, 189.5, 95.4, and 71.1 ppm for B. glabra, D. regia, L. camara, and P. orientalis, respectively. Plant extracts tested in this study showed high insecticidal, antimicrobial, and antioxidant potential. GC-MS and HPLC analyses showed a higher number of terpenes, flavonoids, and phenolic compounds. The ADME analysis of element, caryophyllene oxide, caryophyllene, and copaene showed that they were similar to drugs and that they were better absorbed by the body and able to pass through the blood-brain barrier. Our results confirm the ability of ornamental plants to have promising larvicidal and antimicrobial activity and biotechnology.

Recent Development of Fluoroquinolone Derivatives as Anticancer Agents.

Cancer is the second leading cause of death in the world following cardiovascular disease. Its treatment, including radiation therapy and surgical removal of the tumour, is based on pharmacotherapy, which prompts a constant search for new and more effective drugs. There are high costs associated with designing, synthesising, and marketing new substances. Drug repositioning is an attractive solution. Fluoroquinolones make up a group of synthetic antibiotics with a broad spectrum of activity in bacterial diseases. Moreover, those compounds are of particular interest to researchers as a result of reports of their antiproliferative effects on the cells of the most lethal cancers. This article presents the current progress in the development of new fluoroquinolone derivatives with potential anticancer and cytotoxic activity, as well as structure-activity relationships, along with possible directions for further development.

A synthetic antibiotic class with a deeply-optimized design for overcoming bacterial resistance

The lack of new drugs that are effective against antibiotic-resistant bacteria has caused increasing concern in global public health. Based on this study, we report development of a modified antimicrobial drug through structure-based drug design (SBDD) and modular synthesis. The optimal modified compound, F8, was identified, which demonstrated in vitro and in vivo broad-spectrum antibacterial activity against drug-resistant bacteria and effectively mitigated the development of resistance. F8 exhibits significant bactericidal activity against bacteria resistant to antibiotics such as methicillin, polymyxin B, florfenicol (FLO), doxycycline, ampicillin and sulfamethoxazole. In a mouse model of drug-resistant bacteremia, F8 was found to increase survival and significantly reduce bacterial load in infected mice. Multi-omics analysis (transcriptomics, proteomics, and metabolomics) have indicated that ornithine carbamoyl transferase (arcB) is a antimicrobial target of F8. Further molecular docking, Isothermal Titration Calorimetry (ITC), and Differential Scanning Fluorimetry (DSF) studies verified arcB as a effective target for F8. Finally, mechanistic studies suggest that F8 competitively binds to arcB, disrupting the bacterial cell membrane and inducing a certain degree of oxidative damage. Here, we report F8 as a promising candidate drug for the development of antibiotic formulations to combat antibiotic-resistant bacteria-associated infections.

Performance of Laying Chickens with Feed Additive Cinnamon Flour (Cinnamomum burmanni (Nees & T.Nees) Blume)

Chickens are important commodities due to human need eggs to meet animal protein. Increasing of resistance of bacteria to synthetic antibiotics and consumer understanding of health and food safety have stimulated use of antibiotic growth promoters (AGP) in poultry industry. AGP applied sustainable feed management steps to improve gut health and poultry growth performance. Cinnamon, one of the spices as a natural product. This useful source due to antioxidants, anti-microbial, anti-inflammatory, antifungal, and hypo-cholesterolemic effects and its capability to activate digestion enzymes in intestine. This research aimed to analyze the performance of laying chicken eggs fed with cinnamon flour. The treatments used were cinnamon flour with levels R0 (basal ration, without cinnamon flour/CF, R1 (99.5% BR+ 0.5% CF), R2 (99% BR+ 1% CF), R3 (98% BR + 1.5 % CF), and R4 (98% BR + 2% CF). Data were analyzed with Completely Randomized Design and Duncan's test. Variables were ration consumption, Hen Day Production/HDP and ration conversion. Results showed that adding 2% cinnamon flour significant effect on feed consumption, HDP (P< 0,01) but insignificant on ration conversion (P>0.05). Cinnamon flour as feed additive source up to 2% level can increase the performance of laying hens.

Coatings Based on Essential Oils for Combating Antibiotic Resistance.

In the current era of widespread antimicrobial resistance, the utilization of essential oils (EOs) derived from plants has emerged as a promising alternative in combating pathogens that have developed resistance to antibiotics. This review explores the therapeutic potential of essential oils as valuable tools in restoring the efficacy of antibiotics, highlighting their unique ability to affect bacteria in multiple ways and target various cellular systems. Despite the challenge of elucidating their precise mode of action, EOs have shown remarkable results in rigorous testing against a diverse range of bacteria. This review explores the multifaceted role of EOs in combating bacterial microorganisms, emphasizing their extraction methods, mechanisms of action, and comparative efficacy against synthetic antibiotics. Key findings underscore the unique strategies EOs deploy to counter bacteria, highlighting significant differences from conventional antibiotics. The review extends to advanced coating solutions for medical devices, exploring the integration of EO formulations into these coatings. Challenges in developing effective EO coatings are addressed, along with various innovative approaches for their implementation. An evaluation of these EO coatings reveals their potential as formidable alternatives to traditional antibacterial agents in medical device applications. This renaissance in exploring natural remedies emphasizes the need to combine traditional wisdom with modern scientific advancements to address the urgent need for effective antimicrobial solutions in the post-antibiotic era.

Encapsulated pomegranate peel extract as a potential antimicrobial ingredient from food waste.

Pomegranate peel waste is a valuable reservoir of heat-sensitive total hydrolysable tannins (THT), with potential applications in food and pharmaceuticals. Preserving THT is challenging due to degradation post-extraction. We explore ionic gelation as an encapsulation method to optimize THT utilization. Through external gelation, we optimized the process variables using Box-Behnken design. At 40 g kg-1 sodium alginate, 25 g kg-1 calcium chloride, and 300 g kg-1 pomegranate peel extract (PPE), we achieved an 83.65% encapsulation efficiency. Compared to spray drying, external gelation demonstrated superior performance, with enhanced release percentages and stability. Physical, phytochemical, and release profiles of encapsulates were extensively analysed. External gelation achieved an 87.5% release in 30 min, outperforming spray-dried counterparts (69.7% in 25 min). Encapsulated PPE exhibited robust antibacterial activity against Staphylococcus aureus (ATCC 25923) in powdered infant formula, with a 32 ± 0.01 mm zone of inhibition and 300 μg mL-1 minimum inhibitory concentration. Insights into S. aureus growth curves underlined the mechanism of action via membrane potential alterations. The results of carried investigations also showed that the antibacterial activity of the encapsulated PPE extracts against the targeted organism was identical to the antibacterial activity exhibited by synthetic antibiotics used generally to kill microorganisms in food. Therefore, from the findings, it can be concluded that the PPE encapsulate produced using the external gelation technique at the optimized condition displayed superior storage stability possessing strong antimicrobial activity when compared to encapsulate produced using the spray drying technique. External gelation emerges as a potent technique for developing effective encapsulates enriched with natural antimicrobials or antibiotics. This approach holds promise for applications in food, pharmaceuticals, and nutraceuticals, enhancing stability and efficacy while reducing reliance on synthetic antibiotics. © 2024 Society of Chemical Industry.

Comprehensive in vitro and in vivo evaluation of therapeutic potential of Bacopa-derived asiatic acid against a human oral pathogen Streptococcus mutans.

Dental caries is a common human oral disease worldwide, caused by an acid-producing bacteria Streptococcus mutans. The use of synthetic drugs and antibiotics to prevent dental caries has been increasing, but this can lead to severe side effects. To solve this issue, developing and developed countries have resorted to herbal medicines as an alternative to synthetic drugs for the treatment and prevention of dental caries. Therefore, there is an urgent need for plant-derived products to treat such diseases. Bacopa monnieri, a well-documented medicinal plant, contains 52 phytocompounds, including the pentacyclic triterpenoid metabolite known as asiatic acid (ASTA). Hence, this study aimed to demonstrate, for the first time, the antibacterial activity of phytocompound ASTA against S. mutans. The findings revealed that ASTA significantly inhibited the growth of S. mutans and the production of virulence factors such as acidurity, acidogenicity, and eDNA synthesis. Molecular docking analysis evaluated the potential activity of ASTA against S. mutans virulence genes, including VicR and GtfC. Furthermore, toxicity assessment of ASTA in human buccal epithelial cells was performed, and no morphological changes were observed. An in vivo analysis using Danio rerio (zebrafish) confirmed that the ASTA treatment significantly increased the survival rates of infected fish by hindering the intestinal colonization of S. mutans. Furthermore, the disease protection potential of ASTA against the pathognomonic symptom of S. mutans infection was proven by the histopathological examination of the gills, gut, and kidney. Overall, these findings suggest that ASTA may be a promising therapeutic and alternative drug for the treatment and prevention of oral infection imposed by S. mutans.