Noteworthy Antimicrobial Activity Research Articles

Microbial- and Plant-Derived Bioactive Peptides and Their Applications against Foodborne Pathogens: Current Status and Future Prospects.

Bioactive peptides (BAPs) obtained from plants and microbes have been thoroughly explored and studied due to their prophylactic properties. The use of BAPs seems to be a promising substitute for several currently available antibiotics because of their antimicrobial properties against foodborne pathogens. BAPs have several other useful properties including antitumor, antihypertensive, antioxidant, antiobesity, and antidiabetic activities. Nowadays, scientists have attempted to recombinantly synthesize bioactive peptides to study their characteristics and potential uses, since BAPs are not found in large quantities in nature. Many pathogenic microorganisms including foodborne pathogens are becoming resistant to various antibiotics. To combat these pathogens, scientists are working to find novel, innovative, and safe antimicrobial agents. Plant- and microbe-based BAPs have demonstrated noteworthy antimicrobial activity against a wide range of pathogenic microorganisms, including foodborne pathogens. BAPs can kill pathogenic microorganisms by disrupting membrane integrity, inhibiting DNA and RNA synthesis, preventing protein synthesis, blocking protein activity, or interacting with certain intracellular targets. In addition, the positive effect of BAP consumption extends to gut microbiota modulation and affects the equilibrium of reactive oxygen species in the gut. This article discusses recombinant BAPs, BAPs generated from plants and microbes, and their antimicrobial applications and modes of action for controlling foodborne pathogens.

New strain Brevibacillus laterosporus TSA31-5 produces both brevicidine and brevibacillin, exhibiting distinct antibacterial modes of action against Gram-negative and Gram-positive bacteria.

The growing prevalence of antibiotic resistance has made it imperative to search for new antimicrobial compounds derived from natural products. In the present study, Brevibacillus laterosporus TSA31-5, isolated from red clay soil, was chosen as the subject for conducting additional antibacterial investigations. The fractions exhibiting the highest antibacterial activity (30% acetonitrile eluent from solid phase extraction) were purified through RP-HPLC. Notably, two compounds (A and B) displayed the most potent antibacterial activity against both Escherichia coli and Staphylococcus aureus. ESI-MS/MS spectroscopy and NMR analysis confirmed that compound A corresponds to brevicidine and compound B to brevibacillin. Particularly, brevicidine displayed notable antibacterial activity against Gram-negative bacteria, with a minimum inhibitory concentration (MIC) range of 1-8 μg/mL. On the other hand, brevibacillin exhibited robust antimicrobial effectiveness against both Gram-positive bacterial strains (MIC range of 2-4 μg/mL) and Gram-negative bacteria (MIC range of 4-64 μg/mL). Scanning electron microscopy analysis and fluorescence assays uncovered distinctive morphological alterations in bacterial cell membranes induced by brevicidine and brevibacillin. These observations imply distinct mechanisms of antibacterial activity exhibited by the peptides. Brevicidine exhibited no hemolysis or cytotoxicity up to 512 μg/mL, comparable to the negative control. This suggests its promising therapeutic potential in treating infectious diseases. Conversely, brevibacillin demonstrated elevated cytotoxicity in in vitro assays. Nonetheless, owing to its noteworthy antimicrobial activity against pathogenic bacteria, brevibacillin could still be explored as a promising antimicrobial agent.

Synthesis of green-engineered silver nanoparticles using Cymbopogon citratus (lemongrass) and its antibacterial activity against clinical Pseudomonas aeruginosa

Background and Aim: The use of bioengineered nanocomposites as antimicrobials has increased in recent years, but very few investigations have been conducted to test their effectiveness against Pseudomonas aeruginosa, a pathogen presenting public health risks that can impact both humans and animals. The aim of this study was to assess the antimicrobial potential of phytofabricated silver nanoparticles synthesized using lemongrass extract against clinical isolates of P. aeruginosa. Materials and Methods: The extraction of active compounds from the leaves of Cymbopogon citratus was performed using ethanol (80%) as a solvent, high-performance liquid chromatography-mass spectrometry was used to analyze the chemical composition of the extract, the synthesis of silver nanoparticles (AgNPs) was done using silver nitrate (AgNO3) as a precursor, and the antimicrobial and antibiofilm activity of the extract and the AgNPs phytofabricated was assessed against 10 clinical strains of P. aeruginosa. Results: Lemongrass extract was found to consist of the following main compounds: Caffeic acid (445.21 ± 32.77 μg/g), p-coumaric acid (393.32 ± 39.56 μg/g), chlorogenic acid (377.65 ± 4.26 μg/g), quinic acid (161.52 ± 17.62 μg/g), and quercetin-3-glucoside (151.35 ± 11.34 μg/g). AgNPs were successfully phytofabricated using 2.5 mM AgNO3. The ultraviolet (UV)-visible absorption spectra of the AgNPs showed a localized surface plasmon resonance at 464 nm with an absorbance of 0.32 A. The 50x hydrodynamic diameter was 50.29 nm with a surface area value of 120.10 m2/ cm3, and the volume mean diameter and Sauter mean diameter were 50.63 nm and 49.96 nm, respectively. Despite the compound found in lemongrass extract, no antimicrobial activity was observed with the extract, while AgNPs exhibited noteworthy dose-dependent antimicrobial activity with inhibition diameters up to 24 mm and minimum inhibitory concentration (MIC) and minimum bactericidal concentration ranging from 2 to 16 and 4–64 µg/mL, respectively. AgNPs also demonstrated significant antibiofilm activity by inhibiting biofilms up to 99% between MIC/2 and 2MIC. Conclusion: The present study suggests that lemongrass is a good candidate for the synthesis of AgNPs with good physicochemical characteristics and having a strong anti-pseudomonas activity. Further research is needed to assess the stability and safety of these AgNPs. Keywords: antibiofilm capacity, antimicrobial activity, green synthesis, lemongrass, Pseudomonas aeruginosa, silver nanoparticles.

Exploring the Potency of Medicinal Plants in Central Nepal's Highlands: A Comprehensive Analysis of Antioxidant, Antibacterial Properties, and Toxicity

The current research study aimed to assess the antibacterial, antioxidant, and toxicity effectiveness of eight locally accessible medicinal plants found in the Kavre District of Nepal: Schima wallichii, Woodfordia fruticosa, Cuscuta reflexa, Bombax ceiba, Drymaria diandra, Psidium guajava, Myrica esculenta, and Urtica dioica. Plant extracts were prepared in absolute methanol. The qualitative phytochemical analysis of basic classes of secondary plant metabolites; saponin, sterol, , tannin, quinone, alkaloids, terpenoids, reducing sugar, protein, cardiac glycoside and carbohydrate was carried out. Further, antimicrobial activities, free radical scavenging potential, and toxicity bioassays of the crude extracts were performed. The basic secondary metabolites were detected in all plant extracts. Among the studied plants, W. fructicosa, S. wallichi, M. esculenta, and P. guajava showed noteworthy antimicrobial activities against inspected pathogens. A significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was found in P. guajava, M. esculenta, B. ceiba, W. fructicosa, and U. dioca. Likewise, the highest toxicity potential was observed in C. reflexa followed by U. dioca, B. ceiba, and S. wallichi against Artemia salina. These signifies the potential of plant extracts in herbal medicine. Further work on screening of other biochemical properties will enhance the potential of these plant extracts in modern phytotherapy.

Ethnobotany, Phytochemistry, and Biological Activities of the Genus Cordyline.

Cordyline species have a long history in traditional medicine as a basis of treatment for various ailments such as a bloody cough, dysentery, and a high fever. There are about 26 accepted species names in this genus distributed worldwide, including C. fruticosa, C. autralis, C. stricta, C. cannifolia, and C. dracaenosides. This work presents a comprehensive review of the traditional uses of plants of the genus Cordylie and their chemical constituents and biological activities. A bibliographic search was conducted to identify available information on ethnobotany, ethnopharmacology, chemical composition, and biological activities. A total of 98 isolated compounds potentially responsible for most of the traditional medicinal applications have been reported from eight species of Cordyline and are characterised as flavonoid, spirostane, furostane, and cholestane glycosides. Some of these pure compounds, as well as extracts from some species of Cordyline, have exhibited noteworthy anti-oxidant, antiproliferative, antimicrobial, and hypolipidemic activities. Although many of these species have not yet been investigated phytochemically or pharmacologically, they remain a potential source of new bioactive compounds.

Ultrafast one-pot microwave-assisted green synthesis of silver nanoparticles from Piper longum fruit extract as a sensitive fluorescent nanoprobe for carbamazepine and risperidone in dosage forms and human plasma

A rapid, simple, and green method was developed for the synthesis of highly fluorescent silver nanoparticles (Ag-NPs) using a microwave-assisted synthetic approach in about 30 sec. The developed method used the extract of Piper longum fruit as a reducing agent. Characterization of the obtained Ag-NPs was performed using various microscopic and spectroscopic techniques. The prepared Ag-NPs were applied as a fluorescent probe for the spectrofluorimetric determination of each of carbamazepine (CBZ) and risperidone (RIS). The developed Ag-NPs exhibited a strong emission peak at 354 nm when excited at 265 nm. The mean size of Ag-NPs was found to be 27.3 nm with a polydispersity of 0.351. The developed method is the first spectrofluorimetric method that uses Ag-NPs to determine CBZ or RIS and the only spectrofluorimetric one for RIS determination. Ag-NPs native fluorescence was found to be quantitatively and selectively quenched by both drugs, and method validation exhibited a linear relationship in the range of 20.0–120.0 µM and 5.0–100.0 µM with detection limits of 1.47 µM and 0.84 µM for CBZ and RIS, respectively. The quenching mechanism of Ag-NPs native fluorescence by each CBZ and RIS was studied. The proposed method was then applied to determine CBZ and RIS in their pharmaceutical dosage forms and human plasma samples with high % recoveries and low % RSD. Furthermore, the synthesized Ag-NPs showed noteworthy antimicrobial activities against four different bacterial strains and one species of candida. As a result, the proposed method may have potential uses in antimicrobial therapy and the study of related mechanisms. The greenness of the proposed method was evaluated using two different greenness metric tools, including the complementary green analytical procedure index (Complex GAPI) and Analytical GREEnness (AGREE). Validation of the proposed approach was carried out according to ICH guidelines.

Water-soluble fluorine-functionalized chitooligosaccharide derivatives: Synthesis, characterization and antimicrobial activity

In this work, a series of water-soluble fluorine-functionalized chitooligosaccharide derivatives were synthesized by conjugating nicotinic acid to chitooligosaccharide via nicotinylation reaction, followed by nucleophilic reaction with ethyl bromide, benzyl bromide and fluorobenzyl bromides. Synthesized derivatives were identified structurally by Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance. In addition, the antibacterial activities of chitooligosaccharide derivatives against several disease-causing bacteria were assessed by the broth dilution method and Kirby-Bauer method, the mycelium growth rate method was used to assessing the antifungal properties of samples against three plant-threatening fungi. Among the chitooligosaccharide derivatives, those containing benzyl or fluorobenzyl exhibited noteworthy antimicrobial activity. Specifically, the chitooligosaccharide derivative containing 2,3,4-trifluorobenzyl displayed remarkable antimicrobial activity, with an inhibition index of 84.35% against Botryis cinerea at a concentration of 1.0 mg/mL. Additionally, its MIC value against Staphylococcus aureus was found to be 0.03125 mg/mL, while the MBC value was determined to be 0.0625 mg/mL. The findings of the study revealed that the incorporation of pyridinium cations and fluorine into the chitooligosaccharide backbone may play a critical role in strengthening its ability to combat harmful microorganisms. Furthermore, the cytotoxicities of chitooligosaccharide derivatives against Huvec cells were evaluated through MTT assay, and all samples were not toxic. As a consequence, the water-soluble fluorine-functionalized chitooligosaccharide derivatives possessed rapid microbicidal properties and good biocompatibility, which provided promising prospects for the development of a more effective and environmentally friendly antimicrobial agent.

Diversity of Citrullus colocynthis (L.) Schrad Seeds Extracts: Detailed Chemical Profiling and Evaluation of Their Medicinal Properties.

Seeds and fruits of Citrullus colocynthis have been reported to possess huge potential for the development of phytopharmaceuticals with a wide range of biological activities. Thus, in the current study, we are reporting the potential antimicrobial and anticancer properties of C. colocynthis seeds extracted with solvents of different polarities, including methanol (M.E.), hexane (H.E.), and chloroform (C.E.). Antimicrobial properties of C. colocynthis seeds extracts were evaluated on Gram-positive and Gram-negative bacteria, whereas, anticancer properties were tested on four different cell lines, including HepG2, DU145, Hela, and A549. All the extracts have demonstrated noteworthy antimicrobial activities with a minimum inhibitory concentration (MIC) ranging from 0.9-62.5 µg/mL against Klebsiella planticola and Staphylococcus aureus; meanwhile, they were found to be moderately active (MIC 62.5-250 µg/mL) against Escherichia coli and Micrococcus luteus strains. Hexane extracts have demonstrated the highest antimicrobial activity against K. planticola with an MIC value of 0.9 µg/mL, equivalent to that of the standard drug ciprofloxacin used as positive control in this study. For anticancer activity, all the extracts of C. colocynthis seeds were found to be active against all the tested cell lines (IC50 48.49-197.96 µg/mL) except for the chloroform extracts, which were found to be inactive against the HepG2 cell line. The hexane extract was found to possess the most prominent anticancer activity when compared to other extracts and has demonstrated the highest anticancer activity against the DU145 cell line with an IC50 value of 48.49 µg/mL. Furthermore, a detailed phytoconstituents analysis of all the extracts of C. colocynthis seeds were performed using GC-MS and GC-FID techniques. Altogether, 43 phytoconstituents were identified from the extracts of C. colocynthis seeds, among which 21, 12, and 16 components were identified from the H.E., C.E., and M.E. extracts, respectively. Monoterpenes (40.4%) and oxygenated monoterpenes (41.1%) were the most dominating chemical class of compounds from the hexane and chloroform extracts, respectively; whereas, in the methanolic extract, oxygenated aliphatic hydrocarbons (77.2%) were found to be the most dominating chemical class of compounds. To the best of our knowledge, all the phytoconstituents identified in this study are being reported for the first time from the C. colocynthis.

Optimization of Ethanolic Extraction of Enantia chloranta Bark, Phytochemical Composition, Green Synthesis of Silver Nanoparticles, and Antimicrobial Activity

In this study, using the Box–Behnken model, we optimized the ethanolic extraction of phytochemicals from Enantia chloranta bark for the first time, assessed the composition with HPLC-MS/MS, performed the green synthesis of silver nanoparticles (AgNPs) and characterized them with UV-Vis spectrophotometry, photon cross-correlation spectroscopy, energy-dispersive X-ray fluorescence spectrometry, and Fourier transform infrared spectroscopy. The antibacterial and antibiotic-resistance reversal properties of optimized extract (O-ECB) and AgNPs were assessed on various microorganisms (15 Gram−, 7 Gram+, and 2 fungi) using the well diffusion method and microbroth dilution assay. The mechanism of action was investigated on growth kinetic and proton pumps of Escherichia coli. The in vivo antimicrobial activity and toxicity were assessed on Galleria mellonella larvae. The optimal mass yield (14.3%) related to the highest antibacterial activity (31 mm vs. S. aureus ATCC 6538) was obtained with the following operating conditions: % EtOH—100%; ratio m/v—20 g/mL; and extraction time—6 h. All the compounds identified in O-ECB were alkaloids and the major constituents were palmatine (51.63%), columbamine +7,8-dihydro-8-hydroxypalmatine (19.21%), jatrorrhizine (11.02%), and pseudocolumbamine (6.33%). Among the minerals found in O-ECB (S, Si, Cl, K, Ca, Mn, Fe, Zn, and Br), Br, Fe, and Cl were the most abundant with mean fluorescence intensities of 4.6529, 3.485,4, and 2.5942 cps/uA, respectively. The synthesized AgNPs revealed a strong absorption plasmon band between 430 and 450 nm and an average hydrodynamic diameter ×50 of 59.74 nm, and the presence of Ag was confirmed by a characteristic peak in the spectrum at the silver Kα line of 22.105 keV. Both O-ECB and AgNPs displayed noteworthy and broad-spectrum antimicrobial activities against 20/24 and 24/24 studied microorganisms, respectively, with recorded minimal inhibitory concentrations (MICs) ranging from 8 to ≥1024 µg/mL and 2 to 64 µg/mL. O-ECB and AgNPs showed antibiofilm properties and significantly enhanced the efficacy of conventional antibiotics against selected multidrug-resistant bacteria, and the mechanistic investigations revealed their interference with bacterial growth kinetic and the inhibition of H+-ATPase proton pumps. LD50s were 40 mg/mL and 0.6 mg/mL for O-ECB and AgNPs, respectively. In conclusion, the current study provides a strong experimental baseline to consider Enantia chlorantha bark and their green synthetized AgNPs as potent antimicrobial compounds in this era of antimicrobial resistance.

Insights into Two Novel Orthopalladated Chromophores with Antimicrobial Activity against Escherichia coli.

Advanced chromophoric tools, besides being biologically active, need to meet the expectations of the technological demands including stability, colour retention, and proper solubility for their target. Many coordination compounds of conjugated ligands are antibacterial dyes, able to combine a strong dyeing performance with a useful biological activity. Specifically, palladium (II) complexes of Schiff base ligands are known for their relevant activity against common bacteria. In this article, we report the synthesis and comprehensive experimental and theoretical characterization of two novel Pd(II) chromophore complexes obtained from a cyclopalladated Schiff base as two different chelating azo dyes. The antibacterial response of these two novel complexes was tested against the ubiquitous Escherichia coli bacterium in an aqueous medium and revealed a noteworthy antimicrobial activity, higher than when compared with their uncoordinated biologically active ligands.

1,3,4-oxadiazole derivatives as potential antimicrobial agents.

Due to the emergence of drug-resistant microbial strains, different research groups are continuously developing novel drug molecules against already exploited and unexploited targets. 1,3,4-Oxadiazole derivatives exhibited noteworthy antimicrobial activities. The presence of 1,3,4-oxadiazole moiety in antimicrobial agents can modify their polarity and flexibility, which significantly improves biological activities due to various bonded and non-bonded interactions viz. hydrogen bond, steric, electrostatic, and hydrophobic with target sites. The present review elaborates the therapeutic targets and mode of interaction of 1,3,4-oxadiazoles as antimicrobial agents. 1,3,4-oxadiazole derivatives target enoyl reductase (InhA), 14α-demethylase in the mycobacterial cell; GlcN-6-P synthase, thymidylate synthase, peptide deformylase, RNA polymerase, dehydrosqualene synthase in bacterial strains; ergosterol biosynthesis pathway, P450-14α demethylase, protein-N-myristoyltransferase in fungal strains; FtsZ protein, interfere with purine and functional protein synthesis in plant bacteria. The present review also summarizes the effect of different moieties and functional groups on the antimicrobial activity of 1,3,4-oxadiazole derivatives.

The ethnobotany and antimicrobial activity of selected medicinal plants from Ga-Mashashane, Limpopo Province, South Africa

Ethnopharmacological relevanceDespite the numerous ethnobotanical surveys carried out in the Limpopo Province in recent years, certain areas such as Ga-Mashashane have hitherto not been investigated. This study has revealed some new ethnomedicinal knowledge harboured by the older people of this area. Aim of the studyThe current study aims to document the ethnomedicinal information of the plant species used medicinally for the treatment of gastrointestinal, respiratory, skin, and sexually transmitted infections in the Ga-Mashashane area and to validate the use of the medicinal plant species based on their antimicrobial activities. Materials and methodsEthnobotanical surveys were carried out using structured interviews. A selection of plant species (based on potential anti-infective purposes observed from ethnobotanical interviews) was collected, dried, and ground into fine powder. Organic and aqueous extracts were prepared. The extracts were then screened against pathogens of the gastrointestinal, respiratory, skin, and sexually transmitted infections using the micro-titre plate dilution method. ResultsForty-five species reported to treat various ailments in the study area were recorded. Of these, 22 are used for gastrointestinal disorders, followed by respiratory conditions (18 plant species), skin ailments (16 plant species) and sexually transmitted infections, treated with eight medicinal plant species. The four medicinal plant species; Drimia elata, Elaeodendron transvaalense, Ledebouria revoluta, and Ozoroa sphaerocarpa were reported to treat non-infectious diseases such as high blood pressure, asthma and inflamed/swollen. Twelve new medicinal uses were recorded from 11 species, while the use of one species, Senecio barbertonicus, is reported for the first time in the South African Materia Medica. The study also noted seven plant species with noteworthy antimicrobial activity (MIC values 0.1 mg/ml) against some of the pathogens tested. ConclusionThe study has indicated that medicinal plant utilisation in the Ga-Mashashane area concurs with other South African cultures. There is a correlation between the antimicrobial screening results and ethnobotanical uses, which validates the plants' efficacy.

The Therapeutic Potential of Ethnomedicinally Important Anatolian Thyme Species: A Phytochemical and Biological Assessment

Thyme has been used for various therapeutic purposes in many different cultures, which makes it one of the most riveting medicinal plants throughout history. From its beneficial effects on the respiratory tract or the gastrointestinal system, to its unique skin-related activities, the investigation of the medicinal properties of thyme has always been an alluring topic for researchers aiming to develop conventional medications from this traditional herb. With an incentive to contribute to the extensive thyme research, three Thymus L. species namely Thymus cariensis Hub-Mor. & Jalas (endemic), Thymus praceox subsp. grossheimii (Ronniger) Jalas, and Thymus pubescens Boiss. et Kotschy ex Celak from Turkey were deeply investigated within this study. The analysis of the phytochemical constituents of the extracts was conducted by LC-MS/MS. 12 biologically important secondary metabolites (p-coumaric acid, caffeic acid, salicylic acid, quinic acid, fumaric acid, vanillin, malic acid, rutin, apigenin, naringenin, and nicotiflorin) were detected in all extracts. Their total phenolic and flavonoid contents were calculated (11.15 ± 0.17—61.12 ± 2.59 μg PEs/mg extract, 2.53 ± 0.04—40.28 ± 0.92 μg QEs/mg extract, respectively), and the antioxidant potential of the extracts was evaluated by DPPH and ABTS radical scavenging and CUPRAC activity methods, accordingly, the extracts were shown to possess significant antioxidant activity. Among them, Thymus cariensis Hub-Mor. & Jalas was the most active with IC50 values of 34.97 ± 1.00 μg/ml and 9.98 ± 0.04 μg/ml regarding the DPPH and ABTS radical scavenging assays, respectively, and an A0.5 value of 5.80 ± 0.02 μg/ml according to CUPRAC activity method. Their anticholinesterase, antityrosinase, and antiurease activities were also tested, Thymus cariensis Hub-Mor. & Jalas (35.61 ± 1.20%) and Thymus pubescens Boiss. et Kotschy ex Celak aerial part extract (33.49 ± 1.39%) exhibited moderate antibutyrylcholinesterase activity at 200 μg/ml concentration. The results of the cell viability assay indicated that the extracts demonstrated moderate-to-low cytotoxicity on A498 human renal cell lines. Furthermore, all studied extracts exerted noteworthy antimicrobial activity, especially against Candida tropicalis (MIC values: 19.53—78.12 μg/ml). The presented data substantiates the use of thyme extracts as therapeutic agents in both ethnomedicine and conventional therapies.

Screening of the Antimicrobial Potential of Aqueous Extracts of Some Plants Collected from the City of Narafominsk, Moscow, Russia

Background: The antimicrobial properties of medicinal plants, including those from Russian flora, can be a considerable asset in the fight against antibiotic resistance and the search for new antimicrobials. The present work aimed at assessing the antimicrobial properties of plants collected from the Narafominsk's flora, a city located on the outskirts of Moscow, Russia.
 Methods: The plants were collected from June to August 2021, the extraction was carried out with water as a solvent and the antimicrobial activity of the extracts was tested on 3 referenced microorganisms from the American Type Culture Collection (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538 and Candida albicans ATCC 10231). We determined the inhibition diameters by the well diffusion method, the minimum inhibitory concentrations (MIC) & minimum bactericidal concentrations (MBC) by the microbroth dilution method.
 Results: A total of 59 samples from 33 plants were extracted and included 44.1% of leaves (n=26), 32.2% of flowers (n=19), 8.5% of barks (n=5), 5.1% of whole plant (n =3) and 1 stem and 1 root (1.7%). Inhibition diameters ranged from 0 to 28 mm, MICs and MBCs from 0.5< to >128 mg/ml. 69.49% (n=41) of the plants showed an inhibition diameter greater than zero (>0 mm) against S. aureus, 42.37% (n=25) against E. coli and only 23.72% (n=14) against C. albicans. The plant parts ranked in decrease order of antimicrobial activity were as follows: flower < bark < leaf < whole plant < root < stem < fruit. The plants having shown a noteworthy antimicrobial (MIC ≤0.5 mg/ml) activity against at least 1/3 microorganisms tested and which deserve to be investigated in depth were: flowers of Epilobium angustifolium, Spirea japonica, Heracleum mantegazzianum and Saponaria officinalis, bark of Picea abies and the whole plant extract of Rumex obtusifolius. The second group (1≤ MIC ≤ 4 mg/ml) of plants with no less worthy antimicrobial abilities were flowers of Angelica sylvestris, Arctium minus, Centaurea jacea, Convallaria majalis, Melampyrum nemorosum and Physocarpus opulifolius, leaf of Achillea millefolium and Heracleum mantegazzianum, and bark of Quesrcus robur.
 Conclusion: Flower extracts of Epilobium angustifolium, Spirea japonica, Heracleum mantegazzianum, Saponaria officinalis against are highly recommended for further studies since they presented the best MIC and inhibitions diameters.

Antibacterial efficacy of Lawsonia inermis (Henna) against the predominant endodontic pathogen (Enterococcus faecalis)-An in vitro antimicrobial assay

Introduction and Aim: The prospect of a successful root canal therapy relies on three main factors which includes proper instrumentation, disinfection and obturation of root canal. The goal of the present study is to analyse the anti-microbial efficacy of henna (Lawsonia inermis) against the major endodontic pathogen, Enterococcus faecalis. Materials and Methods: In this study, the antibacterial efficacy of Lawsonia inermis is investigated against Enterococcs feacalis using the method of agar disc diffusion. Extracts of L. inermis were prepared by using methanol as an extraction solvent, whereas DMSO (Dimethyl sulfoxide) and water were used as dissolution solvents. The diluted henna sample was used as the test sample, while positive control used was chlorhexidine gluconate solution and the negative control used was saline. The bacteria were cultured, and the samples were placed to measure the zone of inhibition. Results: Extracts of L. inermis displayed noteworthy antimicrobial activity against E. fecalis. The zone of inhibition of henna against E. fecalis was found to be 11mm whereas the positive control had 14mm. Conclusion: In conclusion, the henna extracts had shown acceptable antimicrobial efficacy and thus this study provides the scientific reason for the use of L. inermis in dentistry.

Chitosan Film Functionalized with Grape Seed Oil—Preliminary Evaluation of Antimicrobial Activity

Although the fishing and wine industries undoubtedly contribute significantly to the economy, they also generate large waste streams with considerable repercussions on both economic and environmental levels. Scientific literature has shown products can be extracted from these streams which have properties of interest to the cosmetics, pharmaceutical and food industries. Antimicrobial activity is undoubtedly among the most interesting of these properties, and particularly useful in the production of food packaging to increase the shelf life of food products. In this study, film for food packaging was produced for the first time using chitosan extracted from the exoskeletons of red shrimp (Aristomorpha foliacea) and oil obtained from red grape seeds (Vitis vinifera). The antimicrobial activity of two films was analyzed: chitosan-only film and chitosan film with the addition of red grape seed oil at two different concentrations (0.5 mL and 1 mL). Our results showed noteworthy antimicrobial activity resulting from functionalized chitosan films; no activity was observed against pathogen and spoilage Gram-positive and Gram-negative bacteria, although the antimicrobial effects observed were species-dependent. The preliminary results of this study could contribute to developing the circular economy, helping to promote the reuse of waste to produce innovative films for food packaging.

Phytochemical analysis and comprehensive evaluation of pharmacological potential of Artemisia brevifolia Wall. ex DC

Multitude of diseases and side effects from conventional drugs have surged the use of herbal remedies. Thus, the current study aimed to appraise various pharmacological attributes of Artemisia brevifolia Wall. ex DC. Extracts prepared by successive solvent extraction were subjected to phytochemical and multimode antioxidant assays. Various polyphenolics and artemisinin derivatives were detected and quantified using RP-HPLC analysis. Compounds present in methanol (M) and distilled water (DW) extracts were identified using high resolution mass spectrometry (HRMS). Extracts were pharmacologically evaluated for their antibacterial, antifungal, antimalarial, antileishmanial and antidiabetic potentials. Moreover, cytotoxicity against Artemiasalina, human cancer cell lines and isolated lymphocytes was assessed. Genotoxicity was evaluated using comet, micronucleus and chromosomal aberration assays. Lastly, anti-inflammatory potential was determined through a series of in vitro and in vivo assays using BALB/c mice.Maximum extract recovery (5.95% w/w) was obtained by DW extract. Highest phenolics and flavonoids content, total antioxidant capacity, total reduction potential, percentfree radical scavenging, β-carotene scavenging and iron chelating activities were exhibited by M extract. RP-HPLC analysis revealed significant amounts of various polyphenolic compounds (vanillic acid, syringic acid, emodin and luteolin), artemisinin, dihydro artemisinin, artesunate and artemether in ethyl acetate (EA) extract. Total 40 compounds were detected through HRMS. A noteworthy antimicrobial activity (MIC 22.22 µg/ml) was exhibited by EA extract against A. fumigatus and several bacterial strains. Maximum antimalarial, antileishmanial, brine shrimp lethality and cytotoxic potential against cancer cells was manifested by EA extract. None of the extracts exhibited genotoxicity and toxicity against isolated lymphocytes. Highest α-amylase and α-glucosidase inhibition capacities were demonstrated by DW extract. Various in-vivo anti-inflammatory models revealed significant (p < 0.05) anti-inflammatory potential of M and DW extracts. In conclusion, present findings divulged theremarkable pharmacological potential of A. brevifolia and endorse its richness in artemisinin.

In vitro antimicrobial activity, antibioresistance reversal properties, and toxicity screen of ethanolic extracts of Heracleum mantegazzianum Sommier and Levier (giant hogweed), Centaurea jacea L. (brown knapweed), and Chenopodium album L. (Pigweed): Three invasive plants.

Background:Plants, including invasive ones, can play a significant role in the fight against antibiotic resistance and the search for new antimicrobials.Aims:The present study aimed at assessing the antimicrobial activity, antibioresistance reversal properties, and toxicity of four samples from invasive plants, namely, Heracleum mantegazzianum (leaves and flowers), Chenopodium album (leaves), and Centaurea jacea (flowers).Methods:The extraction of active compounds was done with ethanol (80%, v/v) and the extraction yields were calculated. Antimicrobial activity was studied using the agar-well diffusion method against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, and Candida albicans ATCC 10231. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined using the mircodilution method. The antibioresistance reversal properties were assessed using the checkerboard method and the toxicity of the extracts was studied using the larval form of the Greater Wax Moth (Galleria mellonella).Results:The mass yields were 11.9, 15.0, 18.2, and 21.5, respectively, for C. jacea flower (CJF), H. mantegazzianum flower (HMF), H. mantegazzianum leaf (HML), and C. album leaf (CAL). The highest inhibition diameters (ID) were found with HMF, CAL, CJF, and HML against S. aureus with 26.6, 21.6, 21.0, and 20.0 mm, respectively. Only CJF and HMF were active against E. coli with respective ID of 15.3 and 19.0 mm. Except HMF (ID = 13.6 ± 2.0 mm), no other extract was active against C. albicans. Moreover, HMF exhibited the lowest MIC (0.5 mg/ml) and the lowest MBC (1 and 4 mg/ml) against both S. aureus and E. coli. Regarding the synergy test, an additional effect [0.5 ≤ fractional inhibitory concentration (FIC) ≤ 1] was found in almost all the combinations antibiotics + extracts excepted for HMF + (Kanamycin or Ampicillin) against S. aureus and CJF + Ampicillin against E. coli where we found synergy effect (FIC ≤0.5). The median lethal doses (LD50s) of HMF, HML, CAL, and CJF were 20.2, 0.58, 13.2, and 4.0 mg/ml, respectively.Conclusion:Only the ethanolic extract of HMFs showed noteworthy broad spectrum antimicrobial activity.

Antimicrobial Formulation of Chrysopogon zizanioides Essential Oil in an Emulsified Lotion for Acne.

Acne is a skin condition arising from excess sebum production and microbial overgrowth within the pilosebaceous unit. Several commercial essential oils have shown promising activity against acne-related pathogens. Due to their volatility and thermal instability, the formulation of essential oils into commercial products remains a pharmaceutical challenge. Thus, this study aimed to develop a viable anti-acne topical treatment as an oil-in-water emulsified lotion to overcome these challenges. Chrysopogon zizanioides (vetiver) displayed noteworthy antimicrobial activity with a mean minimum inhibitory concentration of 0.14 mg/mL against Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Emulsified lotions containing C. zizanioides were developed through the hydrophilic-lipophilic balance approach. At tested hydrophilic-lipophilic balance values of 8, 9, and 10, C. zizanioides emulsified lotions displayed maximum stability at hydrophilic-lipophilic balance 9 with a minimum change in mean droplet size and polydispersity index of 20.61 and 33.33%, respectively, over 84 days. The C. zizanioides emulsified lotion at optimum hydrophilic-lipophilic balance 9 completely inhibited the growth of C. acnes and killed S. aureus, S. epidermidis, and S. pyogenes within 24 h. Additionally, the lotion retained antimicrobial activity against these test micro-organisms over the 84-day stability test period. Thus, the C. zizanioides emulsified lotion demonstrated physical stability and antimicrobial efficiency, making it an ideal natural product anti-acne treatment.

Green-monodispersed Pd-nanoparticles for improved mitigation of pathogens and environmental pollutant

This research, for the first time, demonstrates the synthesis of a novel double chain amphiphilic metallosurfactant complex i.e., bisdecanoatopalladium (II) (complex 1) which provides a template to fabricate monodispersed palladium nanoparticles (Pd NPs). Complex 1 was characterized using CHN, Mass, NMR and FTIR techniques. Complex 1 formed inverted metallomicelles (IMMs) in various n-alcohols and DCM at very low critical aggregation concentration (CAC), (1.19–1.65 × 10−4 M) estimated using conductivity studies. IMMs-supported greener synthesis of Pd NPs suggests the localized and controlled reduction of metalloaggregates and arrested growth of Pd NPs confined in the cavity of IMMs. UV–vis, XRD, HRTEM and DLS techniques have provided a detailed insight into the structure, morphology and dispersibility of as-obtained Pd NPs. The uniform surfactant coating enables the synthesis of highly monodispersed and spherical Pd NPs in a very narrow size of 1–2 nm. This green approach eliminates the existing challenges of controlling size, shape, and dispersibility. The superiority of Pd NPs has been explored in terms of catalytic and biological applications. The Pd NPs are found to be extremely selective, efficient, and eco-friendly and recyclable catalysts for the reduction of para-nitrophenol (PNP) with an achievable rate constant as high as 1.018 min−1 with mere 2 mol% catalyst dose. Pd NPs also exhibit excellent binding ability with BSA protein exhibiting a high binding constant of 9.7 × 105 M−1. Besides, Pd NPs can be promoted as excellent therapeutic agents as they have shown noteworthy (i) antimicrobial activity against pathogenic microbes i.e., Bacillus cereus ITCC 240 (MIC 0.002 μg/mL), Klebsiella pneumoniae ITCC 138 (MIC 0.003 μg/mL) and Curvularia lunata ITCC 6257 (MIC 0.001 μg/mL) and (ii) anticancer activity against human liver cancer cells i.e., HepG2 (IC50 25 μg/mL). The outcomes of this research epitomize Pd NPs as a potential green nano-system having broader prospective in catalytic and biological applications.