Antimicrobial Potential Research Articles

Assessment of 2'-Fucosyllactose and Lacto-N-Neotetraose Solution as an Irrigant in E. faecalis-Infected Root Canals: An In Vitro Study.

Given the lack of an ideal endodontic irrigant on the market, this study evaluates the antimicrobial potential of a formulated solution of 2'-fucosyllactose and lacto-N-neotetraose against E. faecalis within infected root canals, and explores any associated impacts related to the duration of irrigation. 32 single-rooted teeth extracted for periodontal reasons were infected with Enterococcus faecalis, and subsequently subjected to endodontic treatment with two different irrigation systems: sodium hypochlorite or a solution of 2'-fucosyllactose and lacto-N-neotetraose. These samples were then incubated in sterile culture media at 37 °C to observe microbial activity through turbidity. The culture broth of each individual sample was assessed as positive or negative by observing the turbidity or lack of turbidity in the culture at the time of evaluation. the analysis of the results obtained from the comparison of groups irrigated with sodium hypochlorite or a solution of 2'-fucosyllactose and lacto-N-neotetraose demonstrates that the case solution has no bactericidal effect against E. faecalis inoculated in the endodontic system. the HMOs used in this study do not have a bactericidal effect on E. faecalis inoculated in an endodontic system.

Antibacterial Effect of Silver Nanoparticles against Oral Biofilms in Subjects with Motor and Intellectual Disabilities.

Motor and intellectual disabilities (MIDs) represent a great challenge for maintaining general health due to physical and cognitive limitations, particularly in the maintenance and preservation of oral health. Silver nanoparticles (AgNPs) have emerged as a promising therapeutic tool for bacterial control, including oral biofilms; however, knowledge of the bactericidal effectiveness of oral biofilms from patients with MIDs is insufficient. This study aims to determine the antimicrobial effect of AgNPs on different oral biofilms taken from patients with and without MIDs. Two sizes of AgNPs were prepared and characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Through consecutive sampling, biofilm samples were collected from 17 subjects with MIDs and 20 subjects without disorders. The antimicrobial effect was determined by obtaining the minimum inhibitory concentration (MIC) of AgNPs, and the identification and distribution of oral bacterial species were determined by polymerase chain reaction (PCR). Finally, correlations between sociodemographic characteristics and the antimicrobial levels of AgNPs were also explored. The values of the MIC results were analyzed with IBM-SPSS software (version25) using non-parametric tests for independent groups and correlations, with statistical significance being considered as p < 0.05. Both sizes of AgNPs exhibited tight particle size distributions (smaller: 10.2 ± 0.7 nm; larger: 29.3 ± 2.3 nm) with zeta potential values (-35.0 ± 3.3 and -52.6 ± 8.5 mV, respectively) confirming the stability that resulted in little to no agglomeration of nanoparticles. Although both sizes of AgNPs had good antimicrobial activity in all oral biofilms, the smallest particles had the best antimicrobial effects on the oral biofilm samples from patients with and without MIDs, even better than chlorhexidine (CHX) (p < 0.05). Likewise, the patients with disabilities showed higher levels of antimicrobial sensitivity to AgNPs compared with CHX (p < 0.05). Although the microorganisms included in the biofilms of females had a statistically higher growth level, the AgNP antimicrobial effect was statistically similar in both genders (p > 0.05). The most frequent bacteria for all oral biofilms were S. mutans (100%), P. intermedia (91.6%), T. forsythia (75.0%), T. denticola (75.0%), P. gingivalis (66.6%), F. nucleatum (66.6%), S. sobrinus (50.0%), and A. actinomycetemcomitans (8.3%). AgNPs exhibited considerable antimicrobial potential to be used as a complementary and alternative tool in maintaining and preserving oral health in patients with MIDs.

Chemical characterisation, thermal analysis, and antibacterial activity of honeys from Caatinga stingless bees of Melipona spp.

In the present study, chemical characterisation, thermal analysis and antibacterial activity of honeys from Melipona spp. with occurrence in Caatinga biome of Brazil. The honeys presented pH from 4.07 to 4.14, density of 1.41 g/cm3 and °Brix value of 79.90. The thermogravimetry (TG) analysis presented six-seven events and differential thermal analysis (DTA) presented three-four endothermic peaks. HPLC fingerprint revealed a predominant presence of gallic acid and vanillin. Antioxidant activity evaluated using in vitro 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging with IC50 values in the range of 14.5404 to 15.2454 mg/mL. The honeys also showed antimicrobial activities against Staphylococcus aureus and Pseudomonas aeruginosa using a modified agar diffusion and microdilution method. The results of the present study demonstrate that the honey from stingless bees by Caatinga biome indicate polyphenol compounds, antioxidant activity and in vitro antimicrobial potential. The analytical methos permitted of fingerprint of samples.

In vitro antibacterial acitivity of Naproxen and its combination with ciprofloxacin

Naproxen, a nonsteroidal anti-inflammatory drug (NSAID), is commonly used to reduce fever, and to treat pain and inflammation caused by several conditions. Previously, naproxen was evaluated for its antimicrobial potency in various studies. In our study, we aimed to demonstrate the antibacterial and synergistic activities of naproxen and ciprofloxacin against various Gram-positive and Gram-negative bacteria including, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 700603. The results showed promising antibacterial activity against tested Gram-positive bacteria. However, there was no effect on Gram-negative bacteria. Additionally, checkerboard assays did not reveal any additive or synergistic activity when combined with Ciprofloxacin. Collectively, our study's data show naproxen's selectivity against Gram-positive bacteria. This result suggests that naproxen can be further used as a potential source of antibiotics against Gram-positive bacteria.

Polyphenols and Phenolic Glucosides in Antibacterial Twig Extracts of Naturally Occurring Salix myrsinifolia (Salisb.), S. phylicifolia (L.) and S. starkeana (Willd.) and the Cultivated Hybrid S. x pendulina (Wender.).

(1) Background: Salix species occurring in Finland have not been well studied for their antimicrobial potential, despite their frequent use for lung and stomach problems in traditional medicine. Thus, twig extracts of three species of Salix that are found naturally in Finland and one cultivated species were screened for their antimicrobial properties against human pathogenic bacteria. S. starkeana and S. x pendulina were screened for antibacterial effects for the first time. (2) Methods: An agar diffusion and a microplate method were used for the screenings. Time-kill effects were measured using a plate-count and a microplate method. A DPPH-method using a qualitative TLC-analysis was used to detect antioxidant compounds in antimicrobial extracts. Metabolites from a S. myrsinifolia extract showing good antibacterial effects were identified using UPLC/QTOF-MS. (3) Results: A methanol extract of S. starkeana was particularly active against B. cereus (MIC 625 µg/mL), and a methanol extract of S. myrsinifolia showed good activity against S. aureus and B. cereus (MIC 1250 µg/mL) and showed bactericidal effects during a 24 h incubation of B. cereus. Moreover, a decoction of S. myrsinifolia resulted in good growth inhibition against P. aeruginosa. Our UPLC/QTOF-MS results indicated that proanthocyanidins (PAs), and especially the dimer procyanidin B1 (m/z 577) and other procyanidin derivatives, including highly polymerized proanthocyanidins, were abundant in S. myrsinifolia methanol extracts. Procyanidin B1 and its monomer catechin, as well as taxifolin and p-hydroxycinnamic acid, all present in S. myrsinifolia twigs, effectively inhibited B. cereus (MIC 250 µg/mL). (4) Conclusions: This study indicates that Finnish Salix species contain an abundance of antibacterial condensed tannins, phenolic acids and other polyphenols that deserve further research for the antibacterial mechanisms of action.

Nano Zinc Oxide Particle Synthesis from Bio-Waste Selaginella willdenowii Leaf Extract: A Multi-Faceted Approach for Environmental and Biomedical Applications

Selaginella willdenowii, a commonly used greenhouse fern, was often used as a biowaste to synthesize zinc oxide nanoparticles (ZnO NPs) in an eco-friendly and cost-effective way. UV–Visible spectra studies were carried out to confirm the synthesis of S. willdenowii-mediated ZnO NPs (SW-ZnO NPs), and a peak at 367[Formula: see text]nm with a sharp band gap of 3.415[Formula: see text]eV was observed. The X-ray diffraction analysis indicated that the crystalline size of the synthesized SW-ZnO NPs was 11.971[Formula: see text]nm. The phytochemicals present in the extracts and the compounds involved in the reduction of metal to nanoparticles were determined by Fourier Transform Infrared analysis. Scanning electron microscopy was utilized to analyze the surface morphology and size of the obtained SW-ZnO NPs. The examination revealed that they exhibited a hexagonal shape, with an average size falling within the range of 17–23[Formula: see text]nm. Under ultra-violet light, reactive blue 220 and reactive yellow 145 dyes showed 78.06% and 60.14% degradation, showing potential photocatalytic degradation activity. The synthesized SW-ZnO NPs also exhibited antimicrobial activity against bacterial strains (Escherichia coli and Bacillus subtilis) and fungal cultures (Candida tropicalis and Candida albicans) showed cytotoxic activity against Hep-G2 cell lines. Our results suggest the green synthesized SW-ZnO NPs have potential photocatalytic, antimicrobial and cytotoxic potential.

Phytotoxicity, cytogenotoxicity and antimicrobial potential of extracts with gold-silver bimetallic nanoparticles obtained from pteridophyte spores

Investigating the toxicity of naturally occurring or synthesized nanoparticles for various applications is absolutely necessary for environmental protection and safety use. The aim of these research was to investigated the phytotoxicity, cytogenotoxicity and antibacterial potential of the extracts with gold-silver bimetallic nanoparticles (Au-Ag NPs) obtained from green synthesis in Asplenium scolopendrium L. and Dryopteris filix-mas (L.) Schott spores extracts. To our knowledge, this is the first report of the Au-Ag NPs phytosynthesis based on extracts obtained from fern spores. UV-Vis spectroscopy analysis of the samples revealed the maximum absorbance, characteristic of samples with bimetallic nanoparticles, which varied depending on the Au:Ag ratio. Energy-dispersive X-ray spectroscopy confirmed the presence and distribution of Au, Ag and other chemical elements. The presence of specific secondary metabolites in the extracts that helped in NPs biosynthesis stimulated growth processes. Good results were recorded for some Dryopteris filix-mas samples, correlated with a significantly increased mitotic index. Cell viability decreased significantly in three of the nanoformulations. Only extracts with Au-Ag NPs showed antimicrobial effect against Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 8739. The testing of the antibacterial potential of these extracts must be extended to other bacterial strains and other microorganisms, the search of new antimicrobial resources being an urgent necessity nowadays.

Identification of plant based potential antifungal compounds against BMK-1 protein of Bipolaris oryzae using molecular docking approach

Rice brown spot is an important disease of rice worldwide that inflicts substantial yield losses. The antimicrobial potential of methanol, acetone and dimethyl sulfoxide (DMSO) extracts of different medicinal plants, viz., Syzygium aromaticum, Saussurea costus, Acorus calamus, Bergenia ciliate, Geranium pratense, Mentha longifolia, Inula racemosa, Podophyllum hexandrum, Heracleum candicans and Picrorhiza kurroa, against the brown spot pathogen Bipolaris oryzae in vitro was evaluated via mycelial growth inhibition and spore germination inhibition assays. Among the plant extracts tested, 100% mycelial inhibition was observed for the methanol extract of Syzygium aromaticum at all three concentrations (2000 ppm, 3000 ppm and 4000 ppm), followed by the methanol extract of Inula racemosa (90.33%) at 4000 ppm. A maximum conidial germination inhibition of 83.54% was exhibited by the Heracleum candicans leaf extract. Phytochemical profiling of Syzygium aromaticum and Inula racemosa through liquid chromatography and mass spectrometry (HR-LCMS) revealed the presence of several compounds, such as eugenol, ursolic acid, quercetin, chlorogenic acid, and noscapine. A molecular docking approach was used to identify key inhibitory molecules against B. oryzae. Among the compounds detected in S. aromaticum and Inula racemosa, ursolic acid and noscapine were found to have the greatest binding affinity for the Big Mitogen Activated Protein Kinase (BMK-1) enzyme present in B. oryzae. In conclusion, S. aromaticum and Inula racemosa are potent compounds that could serve as lead compounds for drug discovery in the future.

Chemical composition, antioxidant and antimicrobial activities of Vaccinium macrocarpon (Ericaceae) and Camellia sinensis (Theaceae) extracts

In the modern scientific community, considerable attention is given to studying the pharmacological activity of catechin and anthocyanin derivatives. However, a comparative analysis of the antioxidant and antimicrobial activities of extracts rich in anthocyanins and catechins has not been previously conducted. So, the purpose of this work was to study and compare phytochemical composition, antimicrobial and antioxidant potential of Vaccinium macrocarpon L., Ericaceae fruit thick and Camellia sinensis L., Theaceae leaf liquid extracts. The quantification of biologically active substances (BAS) was accomplished with spectrophotometric, titrimetric and HPLC methods of analysis; antioxidant activity was determined by the potentiometric method; antimicrobial and anti-fungi effects was evaluated by the well method and minimum inhibition concentration. The total content of phenolic compounds was 0.47% and 10.10%, organic acids – 4.27% and 1.60% for V. macrocarpon fruit thick and C. sinensis leaf extract. The total content of catechins in the C. sinensis leaf extract was 105,000 mg/kg, where epicatechin-3-O-gallate dominated (37300 mg/kg). The total content of anthocyanins in the V. macrocarpon fruit thick extract was 1280 mg/kg, where peonidin-3-O-galactoside dominated (408 mg/kg). Both extracts possessed a high antioxidant potential, and effective antimicrobial and anti-fungi effects. The antioxidant, antimicrobial and anti-fungi activity of V. macrocarpon fruit extract was higher than C. sinensis leaf extract. In addition, we assumed that anthocyanins had higher antioxidant, antimicrobial and anti-fungi properties than catechins. These findings would promote application of V. macrocarpon fruits extract as pharmaceuticals and nutraceuticals.

Assessment of the Antimicrobial Potency of Unripe Plantain Fruits and Peelings Extracts against Escherichia coli, Staphylococcus aureus and Salmonella typhi

Assessment of the Antimicrobial Potency of Unripe Plantain Fruits and Peelings Extracts against Escherichia coli, Staphylococcus aureus and Salmonella typhi

Isolation of Arborescin from Artemisia absinthium L. and Study of Its Antioxidant and Antimicrobial Potential by Use of In Vitro and In Silico Approaches

This study focused on developing an innovative, straightforward, and economical method utilizing a mixture of readily available solvents to extract arborescin (C2OH2OO8) crystals from Artemisia absinthium L. (A. absinthium). The structural elucidation and characterization were conducted using a suite of techniques including IR spectroscopy, CNHSO elemental analysis, scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), and mass spectroscopy (MS). Density functional theory (DFT) calculations were employed to determine the molecular properties. Antioxidant activity was measured using the DPPH radical scavenging assay and the β-carotene bleaching test. Antimicrobial efficacy was assessed against four bacterial strains and three fungal strains. The molecular docking approach was employed to predict the probable binding patterns and affinities of arborescin with specific target biomolecules. Employing an array of analytical techniques, examination of the isolated crystal from A. absinthium. led to its comprehensive structural elucidation. IR spectroscopy revealed the presence of distinctive functional groups, including a carbonyl group within the γ-lactone and an epoxy group. CNHSO elemental analysis verified that the crystal contained only carbon, hydrogen, and oxygen, a finding corroborated by SEM-EDS analysis, consistent with the molecular structure of arborescin. Additionally, mass spectrometry confirmed the identity of the compound as arborescin, with a molecular ion with a mass m/z = 248. Quantum-Chemical Descriptors revealed that arborescin is resistant to elementary decomposition under standard conditions. Although arborescin demonstrates a relatively low antioxidant capacity, with an IC50 of 5.04 ± 0.12 mg/mL in the DPPH assay, its antioxidant activity in the β-carotene bleaching test was found to be 3.64%. Remarkably, arborescin effectively inhibits the growth of Staphylococcus aureus and Listeria innocua at low concentrations (MIC = 166 µg/mL). Additionally, it exhibits significant antifungal activity against Candida glabrata, with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 83 µg/mL and 166 µg/mL, respectively. In this study, arborescin exhibited a robust docking score of −8.1 kcal/mol, indicating a higher affinity compared to ciprofloxacin. This suggests that arborescin has significant potential as a potent antibacterial agent.

An antibacterial film using κ-carrageenan loaded with benzyl isothiocyanate nanoemulsion: Characterization and application in beef preservation

Benzyl isothiocyanate (BITC) is a naturally active bacteriostatic substance and κ-carrageenan (KC) is a good film-forming substrate. In the present study, a nanoemulsion incorporating BITC was fabricated with a particle size of 224.1 nm and an encapsulation efficiency of 69.2 %. Subsequently, the acquired BITC nanoemulsion (BITC-NE) was incorporated into the KC-based film, and the light transmittance of the prepared composite films was lower than that of the pure KC film. Fourier transform infrared spectroscopy and scanning electron microscopy revealed that BITC-NE was compatible with the KC matrix. BITC-NE incorporation enhanced the tensile strength of the KC-based films by 33.7 %, decreased the elongation at break by 33.8 %, decreased the water vapor permeability by 60.1 %, increased the maximum thermal degradation temperature by 48.8 %, and decreased the oxygen permeability by 42 % (p < 0.05). Furthermore, the composite films showed enhanced antimicrobial activity against Staphylococcus aureus, Salmonella typhimurium, and Pseudomonas fluorescens. The developed KC-based composite films were applied to wrap raw beef, which significantly delayed the increase in total viable count, total volatile base nitrogen content, and thiobarbituric acid reactive substances, and prolonged the shelf-life of the raw beef by up to 10 days. These results indicated that the composite films prepared by incorporating BITC nanoemulsions into KC matrices have great antimicrobial application potential.

Exploring the antimicrobial and antioxidant potential of bacterial cellulose-cerium oxide nanoparticles hydrogel: Design, characterization and biomedical properties

Bacterial cellulose (BC) is a promising natural polymer prized for its biocompatibility, microporosity, transparency, conformability, elasticity, and ability to maintain a moist wound environment while absorbing exudates. These attributes make BC an attractive material in biomedical applications, particularly in skin tissue repair. However, its lack of inherent antimicrobial activity limits its effectiveness. In this study, BC was enhanced by incorporating cerium (IV)-oxide (CeO2) nanoparticles, resulting in a series of bacterial cellulose-CeO2 (BC-CeO2) composite materials. Characterization via FESEM, XRD, and FTIR confirmed the successful synthesis of the composites. Notably, BC-CeO2-1 exhibited no cytotoxic or genotoxic effects on peripheral blood lymphocytes, and it additionally protected cells from genotoxic and cytotoxic effects in H2O2-treated cultures. Redox parameters in blood plasma samples displayed concentration and time-dependent trends in PAB and LPP assays. The incorporation of CeO2 nanoparticles also bolstered antimicrobial activity, expanding the potential biomedical applications of these composites.

Synthesis, Characterization, and Study of the Antimicrobial Potential of Dimeric Peptides Derived from the C-Terminal Region of Lys49 Phospholipase A2 Homologs.

Currently, the search for new alternatives to conventional antibiotics to combat bacterial resistance is an urgent task, as many microorganisms threaten human health due to increasing bacterial resistance to traditional medicines. Thus, new molecules such as antimicrobial peptides have emerged as promising alternatives because of their low induction of resistance and broad spectrum of action. In this context, in the past few years, our research group has synthesized and characterized a peptide derived from the C-terminal region of the Lys49 PLA2-like BthTX-I, named p-BthTX-I. After several studies, the peptide (p-BthTX-I)2K was proposed as the molecule with the most considerable biotechnological potential. As such, the present work aimed to evaluate whether the modifications made on the peptide (p-BthTX-I)2K can be applied to other molecules originating from the C-terminal region of PLA2-like Lys49 from snake venoms. The peptides were obtained through the solid-phase peptide synthesis technique, and biochemical and functional characterization was carried out using dichroism techniques, mass spectrometry, antimicrobial activity against ESKAPE strains, hemolytic activity, and permeabilization of lipid vesicles. The antimicrobial activity of the peptides was promising, especially for the peptides (p-AppK)2K and (p-ACL)2K, which demonstrated activity against all strains that were tested, surpassing the model molecule (p-BthTX-I)2K in most cases and maintaining low hemolytic activity. The modifications initially proposed for the (p-BthTX-I)2K peptide were shown to apply to other peptides derived from Lys49 PLA2-like from snake venoms, showing promising results for antimicrobial activity. Future assays comparing the activity of the dimers obtained through this strategy with the monomers of these peptides should be carried out.

Potentials of Cannabis as versatile additive in consumer, industrial and medicinal products and green synthesis of nanoparticles: A systematic review

Abstract The rapidly growing human population has upsurged the need for natural resources, endangering the environment and widening the gaps between availability and needs. The objective of this review was to compile the reported data on Cannabis- based food, beverage, cosmetics, textiles, composites and medicinal products with an emphasis on the regulatory framework and guidelines on Cannabis use, Cannabis- based green synthesis of NPs, and multiple ways of incorporating Cannabis with emphasis on critical factors to be considered while using Cannabis as an additive. We searched the data across scientific databases such as Google Scholar, SciELO, Medline, PubMed, Science Direct, Scopus, Web of Science, and some conference papers, books, dissertations and government reports. Almost 20 different Cannabis -based food and beverage products with enriched nutrition and 11 cosmetic products have been developed and reported with improved quality. The utilization of Cannabis for the development of textiles, composites and different kinds of medicines like Dronabinol (Marinol®), Nabilone, Sativex® or Nabiximols®, Cannapain® and Cannabis variety based preparations/products (on CBD and THC content basis) including Bedrocan, Bedica, Bedrolite, Bediol and Bedrobinol are available for human use. Various Cannabis NPs, including gold (AuNPs), silver (AgNPs), and selenium (SeNPs), are green synthesized with significant antioxidant, anti-inflammatory, and antimicrobial potentials. Because of the endless need for re-invention and the speedy evolution of the market, industries have found a state-of-the-art opportunity to develop various products and nanoparticles (NPs) using Cannabis as a versatile constituent, however, the efficacy of edible products depends upon the level of psychoactive THC present in Cannabis . Overall, the data provided here on Cannabis -based consumers, industrial and medicinal products, green synthesis of Cannabis NPs, and multiple ways of Cannabis incorporation in products considering possible challenges could add significant contributions to the global Cannabis research.

Feasibility of fractional distillation of Eucalyptus hybrida essential oil for the separation of valuable compounds

Raw essential oil (EO) of Eucalyptus hybrida extracted from the leaves of trees found in Uttarakhand state and nearby areas consists of a mixture of monoterpenoids, sesquiterpenoids and several different volatile compounds of which 1,8-cineole i.e., eucalyptol, a monoterpenoid cyclic ether is a major component. The eucalyptol rich EO also holds antimicrobial, anti-inflammatory, broncholytic and mucolytic potential. In this work experimental tests were done to evaluate the feasibility of batch fractionation or fractional distillation (FD) technique in performing value addition of eucalyptus essential oil. The proximity of boiling points of eucalyptol, limonene and p-cymene act as a barrier in separating these compounds. A two-stage FD procedure was devised, which recovers relatively light terpene fractions in first stage and provides eucalyptol rich fractions in second stage. The GC-MS analysis of the fractionated samples revealed good separation results with three stage-B fractions (B8, B9 and B10) containing >90% purity of eucalyptol, while two stage-A fractions (A1 and A2) containing >90% purity of pinene mixture (α-pinene and β-pinene). FD thus proved to be an effective method for adding value to the eucalyptus EO.

Exploring the bioactive potential of Mentha longifolia from Northeast India: an inclusive study on phytochemical composition and biological activities

Mentha longifolia (Lamiaceae) is regarded as highly valuable aromatic medicinal species with wide range of pharmaceutical application. In the present work, leaf essential oil of M. longifolia was applied for the assessment of in vitro pharmacological potentials and compositional analysis. A sum of 15 compounds were detected by GC-FID and GC-MS analysis of M. longifolia essential oil with total area of 99.98% where major compounds were carvone (59.56%), D-limonene (20.81%), eucalyptol (10.08%). The anti-oxidant potency of M. longifolia was estimated using two methods viz., ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assay where M. longifolia essential oil showed moderate anti-oxidant potency. M. longifolia essential oil revealed high anti-inflammatory and tyrosinase inhibitory activity with an IC50 value 3.68 μL/mL and 1.22 μL/mL respectively compared to standard sodium diclofenac (5.33 μL/mL) and kojic acid (2.28 μL/mL). The acetylcholinesterase (AchE) inhibitory and genotoxic assay was performed, where M. longifolia essential oil revealed strong anti-acetylcholinesterase and anti-genotoxic activity. Anti-microbial potential of M. longifolia essential oil was also where strong anti-bacterial activity was shown against Salmonella typhimurium, Bacillus cereus, Staphylococcus aureus, Micrococcus luteus. For anti-fungal activity, M. longifolia essential oil showed no zone of inhibition against any used strains except Aspergillus flavus. From the present research it was established that M. longifolia essential oil possesses pharmaceutical potential with strong AchE inhibitory, anti-inflammatory, anti-microbial, anti-tyrosinase, anti-genotoxic and anti-oxidant activity which can be used for plant-based drug development in future endeavor.

The ldh Gene Plays a Crucial Role in Mediating the Pathogen Control of Lactiplantibacillus plantarum AR113.

Effectively managing foodborne pathogens is imperative in food processing, where probiotics play a crucial role in pathogen control. This study focuses on the Lactiplantibacillus plantarum AR113 and its gene knockout strains, exploring their antimicrobial properties against Escherichia coli O157:H7 and Staphylococcus aureus. Antimicrobial assays revealed that the inhibitory effect of AR113 increases with its growth and the potential bacteriostatic substance is acidic. AR113Δldh, surpassed AR113Δ0273&2024, exhibited a complete absence of bacteriostatic properties, which indicates that lactic acid is more essential than acetic acid in the bacteriostatic effect of AR113. However, the exogenous acid validation test affirmed the equivalent superior bacteriostatic effect of lactic acid and acetic acid. Notably, AR113 has high lactate production and deletion of the ldh gene not only lacks lactate production but also affects acetic production. This underscores the ldh gene's pivotal role in the antimicrobial activity of AR113. In addition, among all the selected knockout strains, AR113ΔtagO and ΔccpA also had lower antimicrobial effects, suggesting the importance of tagO and ccpA genes of AR113 in pathogen control. This study contributes insights into the antimicrobial potential of AR113 and stands as the pioneering effort to use knockout strains for comprehensive bacteriostatic investigations.

The antimicrobial potential of essential oils and their nanoparticulate formulations as effective antifungals

Fungal infections present a challenge when it comes to topical treatment failure thereby necessitating the need for more effective topical delivery systems. Essential oils have demonstrated noteworthy antifungal activity; however, their volatility limits therapeutic use for skin conditions. This study aimed to investigate the antifungal activity of essential oils alone and in combination. Thereafter, antifungal nanoparticulate formulations were designed using three essential oil combinations against Microsporum canis, Trichophyton mentagrophytes and Candida albicans. The antifungal activity was investigated using the broth microdilution assay to determine the minimum inhibitory concentration (MIC). The formulations were prepared by forming nanoparticles (polymer-based and composite lipid-polymer-based systems), with the preferred formulation encapsulating the essential oil combinations. Characterisation of the formulations was performed with a Zeta-sizer and using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR). The in vitro antifungal activity of the three nanoparticulate formulations was then determined, where a significant (p = 0.002) increase in the average antidermatophyte activity could be observed for all three formulations. The combination of A. sativum and C. martinii displayed the lowest MIC value across all three reference strains (MIC values 0.06-0.38 mg mL-1) and the formulation maintained the antifungal activity with MIC values ranging 0.08-0.36 mg mL-1. A successful combination of essential oils with antifungal activity was achieved thereby emphasising an effective nanoparticulate formulation.

An Evaluation of Antimicrobial Activity of Common Zingiber officinale Cultivars Grown in Sri Lanka

Ginger (Zingiber officinale) has long been a therapeutic agent in traditional medicine systems worldwide and is a leading drug candidate in the pharmaceutical industry. In Sri Lanka, many forms of ginger are often used in the food industry, mainly as a spice; it also plays a vital role in the Ayurvedic medicine system. This study evaluated the antimicrobial activity of the two most cultivated cultivars of Zingiber officinale in Sri Lanka, the Sri Lankan (TG) and Chinese (CG) cultivars. Two types of extracts (ethanol and aqueous) were obtained from the rhizomes of each cultivar. The potential antimicrobial activity of the extracts was tested against three types of pathogenic test organisms, Staphylococcus aureus ATCC 25923, Salmonella typhi DSM 17058, and Escherichia coli ATCC 25922, using the agar well diffusion method along with positive control, chloramphenicol, and negative controls, 95% ethanol or distilled water. In conclusion, both Zingiber officinale cultivars exhibit varying antimicrobial potential, with ethanol extracts showing stronger activity than aqueous ones. None of the extracts was effective against Escherichia coli. The agar dilution method determined the minimum inhibitory concentration (MIC) of each ginger extract. Among the extracts, ethanol extracts showed higher effectivity than aqueous extracts, where all test organisms showed inhibition at a concentration of 20 mg/mL. The antimicrobial activity of the Chinese cultivar outperforms the Sri Lankan cultivar against target organisms, Salmonella typhi, and Staphylococcus aureus.