Minimum Inhibitory Concentration Method Research Articles

Comparison of Colistin Susceptibility via Two Different Methods in Gram-Negative Extensive Drug-Resistance Isolates from ICU Patients.

To compare the susceptibility of colistin by two methods in extensive drug-resistant (XDR) Gram-negative isolates from ICU patients. Cross-sectional comparative analysis. Place and Duration of the Study: Department of Microbiology, Combined Military Hospital Karachi, Pakistan, from August 2022 to February2023. A total of 100 clinical specimens received from the intensive care unit yielded growth of extensively drug-resistant gram-negative bacteria, which were evaluated for polymyxin E susceptibility. The agar dilution method was compared with the reference broth microdilution (BMD) method. Minimum inhibitory concentration (MIC) was noted for both methods. Comparison of the MIC method by agar dilution showed a 90% correlation with the reference method of broth microdilution. With MICs within the acceptable range of the clinical and laboratory standards institute (CLSI) recommendations, 89 isolates were susceptible to colistin, whereas only 11 remained resistant. Polymyxin E's MIC 50 and MIC 90 were determined to be 1 and 2 µg/ml, respectively, with 97% susceptibility. Agar dilution susceptibility method can be used for screening purposes for the susceptibility testing of polymyxin E. This method is reliable and can easily identify the heteroresistance. Extensively drug-resistant, Broth microdilution, Multidrug-resistant, Agar dilution, Minimum inhibitory concentration, Colony forming unit.

Colistin, the last resort antibiotic: challenges in the implementation of its routine susceptibility testing

Background: colistin has become a critical antibiotic for lifethreatening multidrug resistance Gram-negative infections, particularly carbapenemase-producing bacteria. Detecting colistin resistance in routine microbiology laboratories is crucial for combating these fatal infections poses a challenge. Especially in developing countries, there is a need for a cost-effective, rapid, and user-friendly diagnostic method. Objective: implementing the various available methods for colistin testing is a significant challenge in resource-limited settings due to logistic difficulties and the need for technical expertise. Materials and Methods: this study shares experiences and insights gained while implementing in-vitro colistin susceptibility testing in a high-load bacteriology laboratory of a tertiary care center in Delhi, India. The following test methods for colistin susceptibility testing were incorporated in the routine antimicrobial susceptibility testing of our laboratory: Colistin Agar Test, Colistin Broth Disk Elution Test, Broth Microdilution susceptibility testing. Results: inconsistent growth patterns were observed in the colistin agar dilution Minimum Inhibitory Concentration (MIC) method, which could be resolved only after the preparation of fresh plates containing that specific concentration of colistin. The contamination issue of plates on use over a few days was addressed by pouring agar containing various concentrations of colistin in cottonplugged glass tubes. In the colistin broth disk elution test, due to the non-availability of screw-capped 10 mL glass tubes, MacCornety bottles (30 mL) were used. Subcultures were performed from the turbid wells to rule out the growth of contaminants when encountering discordant MIC values or skipped wells on the colistin broth microdilution test. Conclusions: despite several technical issues in in-vitro colistin susceptibility testing, we have successfully implemented it in our laboratory. Our experiences can offer guidance to laboratories that are still in the process of implementing it.

Isolation of a Marker Olean-12-en-28-butanol Derivative from Viscum continuum E. Mey. Ex Sprague and the Evaluation of Its Antioxidant and Antimicrobial Potentials.

Viscum continuum E. Mey. Ex Sprague (Mistletoe) is a semi-parasitic plant that grows on the branches of other trees with reported numerous biological activities. This study was aimed at isolating a compound/s that will be used as a standard reference for quality control of South African-based commercialized mistletoe products and to further perform antioxidant and antimicrobial tests on the isolated compound. A dried sample of mistletoe was ground and extracted successively with hexane, dichloromethane (DCM), acetone and methanol using a serial exhaustive cold maceration procedure. The compound was isolated using column chromatography, and its chemical structure was elucidated using two-dimensional nuclear magnetic resonance (2D NMR) and ultrahigh-performance liquid chromatography-mass spectrometry (UPLC-MS). The antioxidant activity of the compound was determined using DPPH, hydrogen radical scavenging activity and reducing power assays, whereas antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) method. Subjection of the DCM extract to column chromatography resulted in the isolation of a compound elucidated as olean-12-en-28-butanol-1-one, 3-hydroxy-4,4,10, 14, 20-pentamethyl (D4). Both the DPPH, H2O2 radical scavenging activity and reducing power assays revealed a significant antioxidant potential of compound D4 with an IC50 of 0.701 mg/mL, lower than that of gallic acid (0.793 mg/mL) for the H2O2 radical scavenging assay. The results also indicated good antibacterial activity of D4 with an IC50 of 0.25 mg/mL, compared to ciprofloxacin with an IC50 of 0.0039 mg/mL, against two Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and three Gram-positive (Streptococcus pyogenes, Bacillus cereus and Staphylococcus aureus) bacteria. This study is the first to report on the isolation of the olean-12-en-28-butanol derivative from mistletoe of the South African ecotype.

Co-delivery of doxycycline and rifampicin using CdTe-labeled poly (lactic-co-glycolic) acid for treatment of Brucella melitensis infection

Brucellosis poses a significant challenge in the medical field as a systemic infection with a propensity for relapse. This study presented a novel approach to brucellosis treatment, enhancing the efficacy of doxycycline and rifampicin through the use of poly (lactic-co-glycolic) acid coupled with cadmium-telluride quantum dots (Dox-Rif-PLGA@CdTe). The double emulsion solvent evaporation method was employed to prepare Dox-Rif-PLGA@CdTe. The study scrutinized the physicochemical attributes of these nanoparticles. The impact of antibiotic-loaded nanoparticles on Brucella melitensis was evaluated through well diffusion, minimum inhibitory concentration (MIC), and cell culture. The chemical analysis results demonstrated a possibility of chemical reactions occurring among the constituents of nanoparticles. Assessments using the well diffusion and MIC methods indicated that the impact of free drugs and nanoparticles on bacteria was equivalent. However, the drug-loaded nanoparticles significantly decreased the colony-forming units (CFUs) within the cell lines compared to free drugs. In conclusion, the synthesis of nanoparticles adhered to environmentally friendly practices and demonstrated safety. The sustained drug release over 100 h facilitated drug accumulation at the bacterial site, resulting in a heightened therapeutic effect on B. melitensis and improved outcomes in brucellosis treatment. The application of these synthesized nanodrugs exhibited promising therapeutic potential.

The bacteriostatic effect of a new controlled-release carotenoids-silver nanoparticle

Discuss the bacteriostatic effect of a novel controlled release silver nanoparticles carotenoids-silver nanoparticle. Detect the optimal extraction conditions for carotenoids through material liquid ratio, different ultrasonic temperatures and times; Detect the optimal synthesis conditions of carotenoids-silver nanoparticle through different volume ratios, UV irradiation times, and temperatures; Detect the bacteriostatic effects on Escherichia coli and Staphylococcus albus using the minimum inhibitory concentration (MIC) and Oxford cup agar plate diffusion method. The experiment proved that the best extraction effect of carotenoids was achieved when the volume ratio of orange peel powder to ethanol was 1:25, the ultrasound time was 40 min, and the temperature was 50 °C; When the amount of carotenoid extract added is 12 mL, the concentration of silver nitrate is 8 mmol/l, the UV irradiation time is 40 min, and the ultrasound temperature is 60 °C, the synthesized carotenoids-silver nanoparticle has the highest absorbance value; carotenoids-silver nanoparticle have strong inhibitory effects on the growth of both Escherichia coli and Staphylococcus albus. As the concentration increases, the bacteriostatic effect also becomes stronger, especially the strongest inhibitory effect on Staphylococcus albus. It was shown that carotenoids-silver nanoparticle has significant bacteriostatic effects, providing new ideas for the development of bacteriostatic agents in plant resources.

Tri-butyltin(IV)phenoxyacetohydroxamate: Synthesis, characterization, biological evaluation and molecular docking studies

The tri-organotin(IV) complex of composition [n-Bu3Sn(C6H5OCH2CONHO)] has been synthesized by using Bu3SnCl and potassium phenoxyacetohydroxamate ligand (KPAH) in pre-determined molar ratio of methanol and tetrahydrofuran. These are characterized by spectral techniques like FTIR, 1 H NMR and mass spectrometry. Studies on electrochemical processes are carried out using cyclic voltammetry. The in vitro antibacterial and antifungal activities performed by using minimum inhibitory concentration (MIC) method has revealed complex as biologically active. Molecular docking of the ligand and complex has been performed against the fungal receptor (PDB ID: 1UKC) to study the interactions between compound and receptor.

Analysis of total flavonoid and antioxidant activity of coconut shell liquid smoke (Cocos nucifera L.) as an antibacterial

Background: Coconut shell is often used for cooking or treated as waste. Liquid smoke is a by-product of coconut shell processing, which results from condensation of combustion steam. It is divided into grades one, two, and three based on the characteristics and utilisation. It contains phenolic, carbonyl acids and other compounds which act as antioxidants, antibacterials, and antifungals. Objective: To determine the total content of flavonoids, antioxidants and antibacterial activity in liquid smoke. Method: Liquid smoke was produced by a pyrolysator and distilled to produce grades one, two and three. It was then tested for antibacterial activity using the minimal inhibitory concentration (MIC) method against S. aureus and E. coli. The AlCl3 reagent and DPPH method were used to determine the total flavonoid and antioxidant levels, respectively. Results: The MIC of grade one, two, and three coconut shell liquid smoke was 10%; 10%; 5% against S. aureus; and 10%, 5%, and 5% against E. coli. The total flavonoid yields from grades one, two and three were 0.0041, 0.0174, and 0.2741 mg QE/ml, respectively. Test results for antioxidant grades with IC50 values were 142.82, 121.64, and 90.80 µg/mL. Conclusion: Coconut shell liquid smoke has antibacterial activity, contains a certain amount of flavonoids, and also possesses antioxidant activity.

Frankincense (Boswellia serrata) Extract Effects on Growth and Biofilm Formation of Porphyromonas gingivalis, and Its Intracellular Infection in Human Gingival Epithelial Cells.

Frankincense is produced by Boswellia trees, which can be found throughout the Middle East and parts of Africa and Asia. Boswellia serrata extract has been shown to have anti-cancer, anti-inflammatory, and antimicrobial effects. Periodontitis is an oral chronic inflammatory disease that affects nearly half of the US population. We investigated the antimicrobial effects of B. serrata extract on two oral pathogens associated with periodontitis. Using the minimum inhibitory concentration and crystal violet staining methods, we demonstrated that Porphyromonas gingivalis growth and biofilm formation were impaired by treatment with B. serrata extracts. However, the effects on Fusobacterium nucleatum growth and biofilm formation were not significant. Using quantification of colony-forming units and microscopy techniques, we also showed that concentrations of B. serrata that were not toxic for host cells decreased intracellular P. gingivalis infection in human gingival epithelial cells. Our results show antimicrobial activity of a natural product extracted from Boswellia trees (B. serrata) against periodontopathogens. Thus, B. serrata has the potential for preventing and/or treating periodontal diseases. Future studies will identify the molecular components of B. serrata extracts responsible for the beneficial effects.

Comparison of Copper-Tolerance Genes between Different Groups of Acidovorax citrulli.

Acidovorax citrulli populations exhibit genetic and phenotypic variations, particularly in terms of copper tolerance. Group I strains of A. citrulli generally exhibit higher copper tolerance compared to group II strains. This study aims to identify genes involved in copper tolerance to better understand the differences in copper tolerance between group I and group II strains. Representative strains pslb65 (group I) and pslbtw14 (group II) were selected for comparison. Deletion mutants of putative copper-tolerance genes and their corresponding complementary strains were constructed. The copper tolerance of each strain was evaluated using the minimum inhibitory concentration method. The results showed that the copA, copZ, cueR, and cueO genes played major roles in copper tolerance in A. citrulli, while cusC-like, cusA-like, and cusB-like genes had minor effects. The different expression levels of copper-tolerance-related genes in pslb65 and pslbtw14 under copper stress indicated that they had different mechanisms for coping with copper stress. Overall, this study provides insights into the mechanisms of copper tolerance in A. citrulli and highlights the importance of specific genes in copper tolerance.

The antimicrobial effect of different vitamin D compounds on Streptococcus mutans and their impact on glycosyltransferase expression

ABSTRACT Background Streptococcus mutans is a virulent microorganism associated with dental caries. This in vitro study aimed to investigate the antimicrobial effects of Cholecalciferol (D3) and Doxercalciferol (D2), against S. mutans and on glycosyltransferase gene expression. Methods Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of D3 and D2 for S. mutans were determined according to the Clinical Laboratory Standards Institute guidelines. The effect of the compounds on environmental pH in 1% w/v and 5% w/v sucrose broth cultures after 24 hours were assessed colorimetrically. Additionally, their impact on glycosyltransferases gene expression (GtfB, GtfC, GtfD) in 5% w/v sucrose culture was evaluated using quantitative real-time PCR. Results The MBCs of D3 and D2 were 83 µg/ml and 166 µg/ml respectively. Both compounds were effective in preventing the local pH drop <5.5 at ≥166 µg/ml in sucrose supplemented cultures. However, the compounds did not inhibit pH drop at MIC values. Notably, D2 upregulated GtfD expression significantly (p < 0.05) and downregulated GtfB and GtfC. Conclusion Vitamin D2 and D3 inhibited S. mutans mediated pH drop in sucrose supplemented cultures and altered glycosyltransferase expression, suggesting potential therapeutic roles in dental caries prevention. Further research is needed to assess their full impact on S. mutans survival under environmental stresses.

Impact of Polyvinylpyrrolidone-Vinyl Acetate Copolymer and Sodium Starch Glycolate Excipients on Phenolic Extraction from Red Clover: Enhancing Biological Activity and Antioxidant Potential.

Adding certain excipients during the extraction process can enhance the concentration of target compounds, leading to potentially increased biological properties of the plant extract. This study explores the impact of PVP/VAC and SSG excipients on red clover bud extracts, aiming to enhance their concentration of target compounds and, consequently, their biological properties. The antioxidative potential was evaluated using DPPH, ABTS, and FRAP methods, and the chemical profile was determined using mass spectrometry. Antibacterial activity against various strains was determined through the minimal inhibitory concentration (MIC) method. The results revealed that the excipient-enriched samples exhibited significantly elevated antioxidant activities as well as phenolic and flavonoid contents compared to control samples. Notably, sample V1E3 demonstrated the highest antioxidant potential, with 52.48 ± 0.24 mg GAE/g dw (phenolic content), 463 ± 6.46 μg TE/g dw (ABTS), 12.81 ± 0.05 μg TE/g dw (DPPH), and 29.04 ± 1.16 mg TE/g dw (post-column ABTS). The highest flavonoid content was found in the S1E3 sample-24.25 ± 0.17 mg RU/g dw. Despite the increased antioxidant potential, no significant variance in antimicrobial activity was noted between the test samples and controls. This implies that excipients may hold the potential to enhance the biological properties of red clover extracts for pharmaceutical applications. These findings contribute valuable insights into optimizing extraction processes for improved functionality and application of plant-derived compounds in therapeutic formulations.

A comparative study of microwave-assisted and conventional hydro distillation methods for extracting essential oils and evaluating their antimicrobial activity from Cleome khorassanica: novel research

This study reports on the phytochemical analysis and antimicrobial activity evaluation of essential oils extracted from the aerial parts of Cleome khorassanica using both microwave-assisted water distillation (MAHD) and classical hydro distillation (HD). Gas chromatography coupled with mass spectrometry was used to analyze the chemical composition of the essential oils. The main components identified in the MAHD-extracted oil were γ-Cadinene (34.29%) and δ-Cadinene (19.52%), while o-Isopropenyltoluene (46.7%) and Duodecyclic acid (10.96%) were the major components in the HD-extracted oil. The MAHD technique showed higher extraction efficiency in a shorter time than the conventional HD method. The antimicrobial activity of the essential oils was evaluated using the minimum inhibitory concentration (MIC) method. The results showed that the essential oil and methanolic extract of Cleome khorassanica exhibited significant inhibitory activity against Staphylococcus aureus, Aspergillus niger, Aspergillus alternata and Fusarium solani. Gram-positive bacteria and fungi were more susceptible to the essential oil than Gram-negative bacteria. Furthermore, the samples extracted by MAHD demonstrated better antimicrobial activity compared to the HD-extracted oil.

Antimicrobial activities and enzyme inhibition effects of Nepeta species

Various Nepeta species, widely used among the public, have valuable phytochemical contents and clinical and biological activities. For this reason, our study examined the enzyme inhibition and antibacterial properties of methanol: chloroform (1:1) extracts of six Nepeta species. N. aristata showed a higher inhibitory effect than the standard drug on seven of the eight enzymes studied. N. baytopii had a high inhibition effect on urease and lipase. It was determined that N. italica inhibited other enzymes except for urease, CA, and lipase. In addition, BChE is also the only effective plant. N. nuda subsp. albiflora has a high effect on inhibiting urease, AChE, and lipase. N. stenantha and N. trachonitica also showed inhibition effects on urease, AChE, and tyrosinase. In the disc diffusion method of antibacterial activity, extracts against B. cereus had antibacterial activity. The antimicrobial activity of N. aristata extract was effective against P. aerugonisa and K. pneumoniae. Additionally, when looking at the minimum inhibition concentration method of antibacterial activity, Nepeta extracts were effective against most bacteria. This research determined Nepeta extracts are effective natural products with antioxidant and enzyme inhibition activities.

Biological Activities of Galanthus fosteri Extracts: First Demonstration of the Interaction between Chlorogenic Acid and DNA Ligase by Molecular Docking.

Within the Amaryllidaceae family, the bulbous plant species Galanthus fosteri (G. fosteri) belongs to the Galanthus genus. Alkaloids with a broad variety of biological functions are typically found in the flora of this family. The G. fosteri plant's organs' antioxidant activity, antibacterial impact, and antimicrobial qualities were examined in this study. Total flavonoid contents (TFC) and total phenolic contents (TPC) of plant extracts were measured with spectrophotometric methods, and antioxidant activity was determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging technique. The HPLC method was used to determine the phenolic compounds on a component basis. The antibacterial properties of the extracts were assessed using the Kirby-Bauer disc diffusion method, and the minimum inhibitory concentration method against the pathogens Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Additionally, combination tests were performed between the extract and antibiotics. Leaf and stem extracts demonstrated greater antioxidant qualities than bulb extracts, despite the fact that extracts of plant organs did not exhibit appreciable levels of TPC, TFC, or antioxidant qualities. According to the HPLC analysis results, it was determined that chlorogenic acid was present in all of the extracts. In fact, it was determined that only chlorogenic acid was 8.02 (mg/10 g) in G. fosteri bulb peel, which has antimicrobial and antioxidant properties. A molecular docking study has demonstrated for the first time that the antibacterial effect of chlorogenic acid might be due to DNA replication inhibition.

Variability in Chemical Composition and Biochemical Activities of Mentha x piperita L. Essential Oil, in Response to Mycorrhizal Symbiosis and Heavy Metal Stress.

The present paper highlights the effect of Pb/Cd-stress and/or mycorrhizal colonization by Glomus Intraradices on yield, chemical composition, cytotoxicity and antimicrobial activity of Mentha x piperita L. essential oil. Our findings showed that mycorrhizal colonization could be used to improve the essential oil yield of M. x piperita, either in non-stressed or Pb/Cd-stressed plants. GC-MS analysis revealed three chemotypes: linalool/pulegone (32.6/30.8 %) chemotype in essential oils of non-mycorrhizal Pb-stressed plants, menthone/menthyl acetate (30.3/25.1 %) chemotype in essential oils of non-mycorrhizal Cd-stressed plants and menthol (44.6 %) chemotype in essential oils of non-mycorrhizal non-stressed plants, mycorrhizal non-stressed plants and mycorrhizal Pb/Cd-stressed plants. The cytotoxicity of M. x piperita essential oil, evaluated by brine shrimp lethality bioassay, was increased in presence of Pb/Cd-stress (from 379.58 to 72.84 μm/mL) and decreased in mycorrhizal plants (from 379.58 to 482.32 μm/mL). The antimicrobial activity of M. x piperita essential oil, evaluated by disc diffusion method and determination of Minimum Inhibitory Concentration against ten microorganisms, was enhanced by the mycorrhizal colonization and deceased by the Pb/Cd-stress. In conclusion, the inoculation of medicinal plants with mycorrhizal fungi is a real avenue for alleviating abiotic stress and/or increasing the quantity and quality of secondary metabolites in terms of biological activities.

Biosynthesis, Characterization, and Biomedical Applications of Gold Nanoparticles with Cucurbita moschata Duchesne Ex Poiret Peel Aqueous Extracts.

In this study, AuNPs were biosynthesized from Cucurbita moschata fruit peel extracts. Biosynthesized AuNPs exhibited maximum absorbance at a 555 nm wavelength, and XRD analysis indicated that the CM-AuNPs had a particle size of less than 100 nm and a cubic crystal structure. TEM scans revealed that the gold particles exhibited a spherical morphology, with an average size of 18.10 nm. FTIR analysis revealed strong peaks indicating the presence of functional groups involved in the reduction reactions. The surface charge of the biosynthesized AuNPs was determined to be -19.7 mV. The antibacterial and antifungal activities of AuNPs against pathogen strains were assessed by the minimum inhibitory concentration (MIC) method. The cytotoxic effects of CM-AuNPs on cancer cell lines (Sk-Ov-3, CaCo2, and A549) and healthy cell lines (HUVEC) were investigated using the MTT method. The findings indicated that AuNPs biosynthesized by the green synthesis method using C. moschata peel aqueous extract had high inhibition on the growth of pathogenic microorganisms and effective cytotoxic activity against cancerous cell lines at low doses. As a result, it can be concluded that CM-AuNPs will be eminently effective in the production of antibacterial and/or anticancer drugs in the pharmaceutical, food, and cosmetic industries.

Phenolic Content Analysis of Two Species Belonging to the Lamiaceae Family: Antioxidant, Anticholinergic, and Antibacterial Activities.

The Lamiaceae family are utilized as ornamental, medicinal, and food supplements throughout the world. The current study focuses on a comparative analysis of the phenolic compositions and bioactivities (including antioxidant, anticholinergic, and antibacterial activities) of ethanolic extracts derived from the aerial parts of the two species (Lavandula stoechas L. and Thymus sipyleus Boiss). The presence of phenolic compounds and phytochemicals in the plant extracts was identified using the LC-MS/MS technique. The LC-MS/MS analysis revealed that vanillic acid (125,596.66 µg/L) was the most abundant phytochemical in L. stoechas. Kaempferol (8550.52 µg/L) was the most abundant substance in Thymus sipyleus. The assessment of the antioxidant efficacy of the species extracts was conducted using the DPPH (2.2-diphenyl-1-picryl-hydrazyl-hydrate), ABTS (2.2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), Fe3+-Fe2+ reducing, and CUPRAC (Cu2+-Cu+ reducing) assays. The anticholinergic activity of the samples was determined using the acetylcholinesterase (AChE) inhibition assay. The results of antioxidant activity were higher in the T. sipyleus than in the L. stoechas ethanol extracts. The extracts of L. stoechas exhibited radical scavenging activity ranging from 15 to 18%, while T. sipyleus had activity effects ranging from 34% to 38%. The AChE inhibition potential for L. stoechas and T. sipyleus extracts as IC50 values were 0.221 ± 0.01 mg/mL and 0.067 ± 0.02 mg/mL, respectively. The antibacterial effects of the ethanolic extracts of these species against pathogenic bacteria isolates were determined using the MIC (minimal inhibitory concentration) method. These findings indicated that the extracts from L. stoechas and T. sipyleus possess the potential to be natural antioxidants in the realm of food preservation. Additionally, their antioxidant, anticholinergic, and antimicrobial properties suggest potential therapeutic utility in the management of certain diseases.

Anti-bacterial and anti-inflammatory properties of ethanol extract of Melicope pteleifolia, an ethnomedicine in Southwest China

BackgroundTraditionally, Melicope pteleifolia has been used for heat clearing and detoxifying, traumatic injuries, bruise, and snake or insect bite. Up to now, its effect on sepsis remains unknown. MethodsMinimum inhibitory concentration (MIC) and dynamic antibacterial curve, and bacteria-induced sepsis mouse models were used to assess the anti-bacterial effect of Melicope pteleifolia ethanol extract (MPE) in vitro and in vivo. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells and cecum ligation and puncture (CLP)-induced sepsis mouse model were used to assess the anti-inflammatory effect of MPE in vitro and in vivo. ResultsMPE treatment significantly inhibited the growth of some pathogenic bacteria and increased survival rates of the sepsis mice challenged with the bacteria. In addition, MPE markedly reduced increased supernatant TNF-α and IL-6 levels. Further, it remarkably downregulated protein expressions of TLR4, MyD88, and NF-κB in the LPS-treated cells. Similarly, MPE significantly increased the survival rate, reduced the serum TNF-α and IL-6 levels of the CLP-induced sepsis mice. Importantly, it attenuated the CLP-induced pathological injuries of small intestines. Moreover, the anti-inflammatory effects of MPE in vitro and in vivo were not significantly abolished in presence of TAK-242 or JSH-23. In addition, MPE changed composition of intestinal flora at phylum and genus levels. Further, MPE affect some metabolism pathways such as carbohydrate, lipid metabolism, other amino acids metabolism, drug resistance, and others. Kaempferol (KAF), quercetin (QC), and N-p-coumaroyl-tyramine (NPC) were characteristic components possessing moderate binding to pathogenic associated molecular patterns (PAMPs) kdo2-Lipid A ammonium (KLA) and ODN 1826. ConclusionIn summary, MPE exerts anti-bacterial and anti-inflammatory effects, and its anti-inflammatory activity is independent of the TLR4/MyD88/NF-κB pathway.

A novel defensin-like peptide C-13326 possesses protective effect against multidrug-resistant Aeromonas schubertii in hybrid snakehead (Channa maculate ♀ × Channa argus ♂).

The purpose of this study was to investigate whether a defensin-like antimicrobial peptide (C-13326 peptide) identified in Hermetia illucens could possess protective effect against multidrug-resistant Aeromonas schubertii in hybrid snakehead (Channa maculate ♀ × Channa argus ♂). The cDNA of C-13326 peptide comprised 243 nucleotides encoding 80 amino acids, with six conserved cysteine residues and the classical CSαβ structure. The recombinant expression plasmid pPIC9K-C-13326 was constructed and transformed into GS115 Pichia pastoris, and the C-13326 peptide was expressed by induction with 1% methanol. The crude extract of C-13326 peptide was precipitated by ammonium sulfate, assayed by Braford method, detected by tricine-SDS-PAGE, evaluated by BandScan software and identified by liquid chromatography-mass spectrometry. The C-13326 peptide was shown to have inhibitory activity against the growth of multidrug-resistant A. schubertii DM210910 by using the minimum growth inhibitory concentration and Oxford cup method. In addition, scanning electron microscopy analysis suggested that C-13326 peptide inhibited the growth of A. schubertii DM210910 by damaging the bacterial cell membrane. To explore the role of peptide C-13326 invivo, hybrid snakehead was fed with peptide C-13326 as feed additives for 7 days. The results revealed that C-13326 peptide could significantly down-regulate the expression levels of IL-1β, IL-8, IL-12 and TNF-α (p < .05), and significantly improved the survival rate of hybrid snakehead after challenging with A. schubertii DM210910. Therefore, the C-13326 peptide is a promising antimicrobial agent for A. schubertii treatment in aquaculture.

Exploring the potential of tannin-rich tree bark extracts in combating foodborne diseases and gastric cancer

The objective of this study was to perform chemical characterization of tannin-rich extracts obtained from the bark of woody species and to assess their bioactive potential for the treatment of foodborne diseases and gastric cancer. The barks of Anacardium occidentale, Stryphnodendron adstringens, and a commercial tannin from Acacia mearnsii were used to prepare the extracts. HPLC was employed to determine the profile and quantity of phenolic compounds present in the extracts, while FTIR was utilized to identify their functional groups. The antioxidant activity was assessed using the DPPH assay, while the antimicrobial activity was evaluated by the disk diffusion method and measurement of minimum inhibitory concentration and minimum bactericidal concentration. Additionally, the antitumor activity was evaluated using the MTT-tetrazolium assay. The phenolic profile of the extracts revealed the presence of ten compounds, with gallic acid and catechin being the most abundant for all species. Hydroxyl (OH) was the recurrent functional group in all the analyzed extracts. At a concentration of 25 μg/mL, the extracts exhibited DPPH free radical scavenging activity of 90%. The extracts had significant antitumor potential, inhibiting the growth of human gastric adenocarcinoma cells (AGS) by 90% at 200 μg/mL. Listeria monocytogenes was the most sensitive bacterium to the use of the extracts, while Escherichia coli was the most resistant. In conclusion, the results obtained in this study demonstrated the promising potential of tannin-rich extracts from the studied species as antioxidant, antimicrobial, and anticancer agents.