Search Results (26)

The purpose of this study was to identify the potential inhibitory effects of extracts of garlic, ginger, and onion on Escherichia coli and Staphylococcus aureus, which had been previously isolated from milk of dairy cows with mastitis. Garlic, ginger, and onions were crudely pressed, and the extracts were filtered and tested for their ability to inhibit bacterial growth at a wide range of concentrations, from undiluted to 1:512 (2⁻⁹). Their inhibitory properties were compared to positive controls containing ampicillin and ceftiofur, and negative controls containing only the nutrient medium and bacteria. Each plate contained quality control organisms E. coli ATCC 25922 and S. aureus ATCC 25923. The colorimetric microdilution method with resazurin as an indicator of bacterial growth was used to determine the minimum inhibitory concentrations. In addition, the minimum bactericidal concentrations of the extracts were assessed. The minimum inhibitory concentrations of garlic extracts were 1.56 µL/mL and 3.12 µL/mL for E. coli and S. aureus, respectively. The minimum bactericidal concentrations of garlic extract against E. coli and S. aureus were 12.5 and 25 µL/mL, respectively. For both ginger and onion, no inhibition was detected at the full concentration of the extracts, but garlic extract demonstrated in vitro inhibition against both E. coli and S. aureus. Future studies should evaluate the ability of garlic extracts to achieve an inhibitory concentration in milk and explore its potential activity in naturally infected mammary glands. Full article

Background: Nowadays, to improve animal production sustainably, the zootechnical sector is exploring novel, functional ingredients, such as seaweed. This study investigated the functional properties of Fucus vesiculosus and their persistence after simulated digestion. Methods: F. vesiculosus was nutritionally characterized (AOAC methods) and digested in vitro through the INFOGEST protocol. The polyphenol, flavonoid, and phlorotannin contents of the samples were analyzed through colorimetric assays. The antioxidant properties were evaluated using ABTS assay and the growth inhibition capacity against Escherichia coli using the microdilution method. The cytotoxic activity and anti-inflammatory properties were evaluated on mouse peritoneal macrophages using crystal violet assay and the gene expression of IL-1β, IL-6, TNF-α, and iNOS. Results: F. vesiculosus demonstrated high levels of dietary fiber (47.36%) and protein (13.99%). Significant levels of polyphenols (6428.98 µg TAE/g), flavonoids (5171.31 µg CE/g), and phlorotannins (2.10 mg PGE/g) were detected. These bioactive compounds allowed for strong antioxidant activity (85.96% ABTS+ scavenging) and E. coli growth inhibition (17%). Simulated digestion minimally impacted the content of bioactive compounds and their associated functional properties. F. vesiculosus exhibited a protective effect against oxidative stress in macrophages, downregulating pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). Conclusions: These findings support the potential of F. vesiculosus as a functional feed ingredient for livestock, maintaining its beneficial properties even after digestion. Full article

Background/Objectives: Antibiotic-resistant bacteria pose a global health threat, driving the need for alternative treatments. Medicinal plants such as Clerodendrum glabrum and Gardenia volkensii are promising sources of bioactive compounds. This study evaluated the antioxidant, antibacterial, and anti-virulence activities of their acetone extracts, comparing sonication and conventional shaking extraction methods. Methods: Colorimetric methods assessed total polyphenol content. Antioxidant activity was measured using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and hydrogen peroxide (H₂O₂) assays. Antibacterial effects against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes were analysed through broth microdilution, total activity, growth kinetics, and combinational studies. Anti-virulence activity was assessed via biofilm biomass inhibition, metabolic activity and anti-swarming assays. Results: Phenolics were the most abundant phytochemicals, followed by flavonols. C. glabrum exhibited strong antioxidant activity in both DPPH and H₂O₂ assays. MIC values ranged from 0.16 to 2.5 mg/mL, with the shaken G. volkensii leaf extract showing the highest total activity (575 mL/g) against E. coli. A combination of G. volkensii leaf extract and gentamicin resulted in an additive antibacterial effect. All extracts prevented the formation of biofilm biomass in all tested microorganisms (inhibition > 50%) except for extracts obtained by sonication. The sonicated leaf extract of C. glabrum inhibited initial E. coli attachment. Additionally, the sonicated leaf extract of C. glabrum inhibited P. aeruginosa motility. Conclusions: These findings suggested that a targeted approach based on plant species and extraction methods could improve treatment outcomes against biofilm-associated pathogens. Notably, acetone extracts derived from C. glabrum and G. volkensii exhibit considerable potential as natural sources of antioxidant, antibacterial, and anti-virulence agents effective against nosocomial infections. Full article

Litsea cubeba essential oil (LCEO) has been reported as an antibacterial agent, but its effects against Salmonella typhimurium (S.Tm) and the underlying mechanisms remain unclear. The antibacterial efficacy of LCEO was assessed utilizing both microdilution and growth curve methodologies, and its chemical composition was thoroughly analyzed. Morphological alterations in the cells were observed through scanning electron microscopy (SEM), while cellular permeability was gauged based on the variations in nucleic acid and protein contents. The impact of LCEO on ATPase activity and its anti-biofilm formation activity was assessed using colorimetric methods. The results indicated that the MIC and MBC of LCEO against S.Tm were 0.4 mg/mL and 0.8 mg/mL, respectively. SEM and PI staining revealed disrupted bacterial cell integrity. Compared to those in the control group, treatment with LCEO significantly elevated the levels of extracellular nucleic acids and proteins (p < 0.05). Furthermore, at the MIC, LCEO led to a 77.9% reduction in AKP content, and decreased intracellular Na⁺K⁺-ATPase and Ca²⁺Mg²⁺-ATPase activities by 79.9% and 54.6%, respectively. Additionally, LCEO markedly inhibited biofilm formation, enhanced surface hydrophobicity, and diminished the swimming motility of S.Tm. Overall, LCEO exhibited promising antibacterial properties, indicating its potential as an effective inhibitor against S.Tm. Full article

Background/Objectives: This study investigates the phytochemical profile, essential oil composition, and bioactivities—including antioxidant, antimicrobial, antibio-film, and anti-quorum sensing (QS) activities—of four Heracleum L. species (H. crenatifolium Boiss, H. paphlagonicum Czeczott, H. sphondylium subsp. montanum Schleich. ex Gaudin, and H. pastinacifolium subsp. incanum (Boiss. & A.Huet) P.H.Davis). Methods: Total phenolic and flavonoid contents were quantified using the Folin–Ciocalteu and aluminum chloride colorimetric methods, respectively. Essential oils were extracted by hydrodistillation and analyzed via Gas Chromatography–Flame Ionization Detector (GC–FID) and Gas Chromatography–Mass Spectrometry (GC–MS), while Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) evaluated chemical variability among the species. Antioxidant activities were assessed using DPPH and ABTS free radical scavenging assays. Antimicrobial activity was assessed using the broth microdilution method to determine Minimum Inhibitory Concentration (MIC) values, while antibiofilm activity was evaluated using an in vitro microplate-based biofilm model against Pseudomonas aeruginosa PAO1. Anti-QS activity was analyzed using a disc diffusion assay with Chromobacterium violaceum ATCC 12472 as the reporter strain. Results: It was observed that the amounts of total phenolic compounds and total flavonoids were higher in root extracts than in aerial parts extracts for the four species in this study (H. sphondylium subsp. montanum excluding phenolic content). In the analysis of essential oil, it was determined that the major component in the roots was mostly myristicin, and in the fruits it was mostly octyl acetate. Phenolic and flavonoid contents were positively correlated with antioxidant activity. Methanol and n-hexane extracts of H. pastinacifolium (aerial parts) and n-hexane extracts of H. paphlagonicum (root) exhibited notable antimicrobial activity, primarily against Gram-positive bacteria, but none of the extracts showed activity against Klebsiella pneumoniae ATCC 13383 or P. aeruginosa ATCC 27853. Among methanol extracts, H. pastinacifolium (aerial parts) exhibited the highest antibiofilm activity (73.2%), while H. paphlagonicum (aerial parts) showed the highest activity among n-hexane extracts (75.5%). All n-hexane extracts exhibited anti-QS activity, whereas the methanol extracts showed no activity. Conclusions: These findings underscore the chemical diversity and bioactive potential of Heracleum species, contributing to the chemotaxonomic understanding of the genus and supporting their potential applications in medicine and industry. To our knowledge, this is the first study that reveals the antibiofilm and anti-QS properties of these Heracleum species. Full article

Background/Objectives: Astragalus L. is a genus of the Fabaceae family, encompassing over 3000 species globally, with 380 species found in Turkey. This is the inaugural examination of the phytochemical, antioxidant, antibacterial, and cytotoxic properties of Astragalus pisidicus. Methods: The water and methanolic fractions of four parts (stems, flowers, leaves, root) as well as the whole plant were quantified and identified by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC–ESI–MS/MS) analysis. Cell death was assessed using the WST-1 assay, while apoptosis was identified by colorimetric protease assay for caspase 2, -3, -6, -8, and -9, as well as cellular DNA fragmentation assay. Antioxidant activity of A. pisidicus water and methanolic extracts was investigated with eight different assays. Antimicrobial activities of the extracts were evaluated against 16 bacterial strains by disc diffusion and broth microdilution methods. Results: A total of 13 phytochemicals were detected in the extracts at various concentrations. Hesperidin (147–40,174 µg/g extract) and hyperoside (363–2677 µg/g extract) comprised the principal constituents among the extracts. Fm (IC₅₀ = 9.57 µg/mL), Rm (IC₅₀ = 14.89 µg/mL), and Sm (IC₅₀ = 9.57 µg/mL) were evaluated as active crude extracts on H1299, HT-29, and Panc-1 cells, while Rm (IC₅₀ = 32.057 µg/mL) and Fm (IC₅₀ = 64.25 µg/mL) were assessed as moderately active on MCF-7 and 22RV1 cells, respectively. The elevation of caspase 2, 3, 6, 8, and 9 enzyme activities, along with DNA fragmentation, signifies that the mode of cell death is apoptosis. According to the disc diffusion test results, Fm, Lm, Sm, and WPm extracts exhibited antimicrobial activity against gram (+) bacteria. Conclusions: A. pisidicus elicited apoptotic cell death in cancer cells selectively by the activation of caspases and subsequent DNA fragmentation and may serve as a novel source of an apoptosis-inducing anticancer drug. Full article

The genus Inula has been used in folk medicine for centuries; however, the data concerning Inula britannica L. are scarce. This study aimed at investigating the chemical composition of methanolic and ethanolic extracts from the aerial parts of I. britannica collected in Kazakhstan and evaluating their antimicrobial and antioxidant properties, with special attention being paid to polyphenols. The total content of polyphenols and flavonoids in the extracts was determined colorimetrically, while their qualitative and quantitative analyses were conducted using HPLC/ESI-QTOF-MS and RP-HPLC/DAD. Their antioxidant potential was determined using the FRAP and DPPH methods, whereas their antimicrobial activity was determined by the microdilution method towards a panel of reference microorganisms, including pathogens of the human gastrointestinal tract. Chemical analysis demonstrated that the methanolic extract had a higher content of polyphenols (58.02 vs. 43.44 mg GAE/g) and flavonoids (21.69 vs. 13.91 mg QUE/g) than the ethanolic extract. In both extracts, 15 compounds were identified, with the highest contents being those of cynarine (13.96 and 11.68 mg/g) and chlorogenic acid (9.22 and 5.09 mg/g). The DPPH assay showed a higher antioxidant activity of the methanolic extract (19.78 ± 0.12 mg GAE/g) in comparison to that of the ethanolic extract (15.56 ± 0.24 mg GAE/g). Similarly, the FRAP method showed that the methanolic extract exerted a much higher antioxidant activity (5.07 ± 0.18 mmol Fe²⁺/g) than the ethanolic extract (0.39 ± 0.01 mmol Fe²⁺/g). In contrast, both extracts showed similar antimicrobial properties, with the highest activity being that against Helicobacter pylori ATCC 43504 (MIC = 0.125–0.25 mg/mL). This paper presents novel data on I. britannica L., implying its significance as a source of valuable active compounds and being a prerequisite for further biological studies. Full article

Biotechnological active peptides are gaining interest in the cosmetics industry due to their antimicrobial, anti-inflammatory, antioxidant, and anti-collagenase (ACE) effects, as well as wound healing properties, making them suitable for cosmetic formulations. The antimicrobial activity of peptides (2–10 kDa) secreted by Saccharomyces cerevisiae Ethanol-Red was evaluated against dermal pathogens using broth microdilution and challenge tests. ACE was assessed using a collagenase activity colorimetric assay, antioxidant activity via spectrophotometric monitoring of nitrotetrazolium blue chloride (NBT) reduction, and anti-inflammatory effects by quantifying TNF-α mRNA in lipopolysaccharides (LPS)-exposed dermal fibroblasts. Wound healing assays involved human fibroblasts, endothelial cells, and dermal keratinocytes. The peptides (2–10 kDa) exhibited antimicrobial activity against 10 dermal pathogens, with the Minimum Inhibitory Concentrations (MICs) ranging from 125 µg/mL for Staphylococcus aureus to 1000 µg/mL for Candida albicans and Streptococcus pyogenes. In the challenge test, peptides at their MICs reduced microbial counts significantly, fulfilling ISO 11930:2019 standards, except against Aspergillus brasiliensis. The peptides combined with Microcare^Ⓡ SB showed synergy, particularly against C. albicans and A. brasilensis. In vitro, the peptides inhibited collagenase activity by 41.8% and 94.5% at 250 and 1000 µg/mL, respectively, and demonstrated antioxidant capacity. Pre-incubation with peptides decreased TNF-α expression in fibroblasts, indicating anti-inflammatory effects. The peptides do not show to promote or inhibit the angiogenesis of endothelial cells, but are able to attenuate fibrosis, scar formation, and chronic inflammation during the final phases of the wound healing process. The peptides showed antimicrobial, antioxidant, ACE, and anti-inflammatory properties, highlighting their potential as multifunctional bioactive ingredients in skincare, warranting further optimization and exploration in cosmetic applications. Full article

Tenebrio molitor larvae represent a sustainable protein source for food and feed. The aim of this study was to evaluate the supplementation of chestnut shell, a by-product of the agro-industrial chain, in growth substrates for T. molitor larvae rearing. Seven-week-old larvae were reared on three different growth substrates: the control group (CTRL) was fed wheat bran, treatment group one was fed wheat bran supplemented with 12.5% w/w chestnut shell (TRT1), and treatment group two was fed wheat bran supplemented with 25% w/w chestnut shell (TRT2). Larval weight, substrate consumption, and mortality were recorded weekly. After 14 days, insect meals were produced for bromatological and colorimetric analysis, and bacterial inhibition activity assay using a microdilution method. The amino acid profile of insects was determined using quantitative nuclear magnetic resonance spectroscopy. Our results showed a lower feed conversion ratio and higher larval survival rate % in TRT2 compared to CTRL (p < 0.05). Proteins and lipids of TRT2 were higher than other groups (p < 0.05). Important differences were observed in the amino acid profile of TRT1 and TRT2 compared to CTRL (p < 0.05). TRT1 and TRT2 showed higher E. coli inhibitory activity than CTRL (p < 0.05). In conclusion, chestnut shell supplementation improved the survival and functional characteristics of larvae and likely impacted the insects’ metabolism. Full article

Background: Recent developments in addressing dental aesthetic concerns, encompassing issues like teeth discoloration and halitosis, underscore the demand for safer alternative solutions. Purpose: This study aims to confirm the effects of lactic acid bacteria (LAB) from kimchi on artificial teeth bleaching and their potential impact in terms of preventing halitosis-related bacteria. Materials and Methods: To evaluate the antimicrobial effects against oral pathogens, disc diffusion tests and broth microdilution methods were used. Additionally, crystal violet analysis was performed to confirm the biofilm inhibition effect. The bleaching effects on stained artificial teeth were analyzed using the CIEDE2000 colorimetric method. Statistical analyses were performed using GraphPad Prism 9 with one-way and two-way ANOVA, with the significance level set at α < 0.05. Results: The strain THK-30, isolated from kimchi, exhibited antibacterial activity against Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum, and was identified as Pediococcus inopinatus. Moreover, THK-30 showed a synergistic antibacterial effect against Gram-negative oral pathogens with 8% sodium hexametaphosphate (SHMP). In the stained artificial teeth bleaching test and artificial teeth biofilm inhibition test, the cell-free supernatant of THK-30 displayed significant teeth bleaching effects and caused the inhibition of biofilm formation, both independently and in combination with SHMP 8%. Conclusions: This study has demonstrated the potential applicability of LAB in teeth discoloration and halitosis. These findings are poised to provide a foundation for the development of research pertaining to the control of oral bacteria. Full article

Shigellosis is a pathological condition that affects the digestive system and possibly causes diarrhoea. Shigella species, which are responsible for this disease, are highly contagious and spread through contaminated food and water. The increasing development of resistance by Shigella species necessitates the urgent need to search for new therapies against diarrhoea-causing shigellosis. The scientific validation of medicinal plants, such as Diospyros gilletii, which is used for the traditional treatment of diarrhoeal conditions is worthwhile. The present study aims to investigate the antibacterial activity of extracts from D. gilletii against selected Shigella species. Extracts from D. gilletii stem bark were prepared by maceration using various solvents. The antibacterial activity of D. gilletii extracts was evaluated in Shigella dysenteriae, S. flexneri, S. boydii, and S. sonnei using a microdilution method, whereas a cytotoxicity test was performed on Vero and Raw cells using resazurin-based colorimetric assays. Bacterial membrane-permeability studies were evaluated using propidium iodide (PI)- and 1-N-phenyl-naphthylamine (NPN)-uptake assays, whereas inhibition and eradication tests on bacterial biofilms were carried out by spectrophotometry. As a result, methanol, ethanol and hydroethanol (water: ethanol; 30:70, v/v) extracts of D. gilletii inhibited the growth of S. boydii, S. flexneri and S. sonnei, with minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg/mL, without toxicity to Vero and Raw cells. Time-kill kinetics revealed bactericidal orientation at 2 MIC and 4 MIC and a bacteriostatic outcome at 1/2 MIC. The mechanistic basis of antibacterial action revealed that D. gilletii extracts inhibited and eradicated Shigella biofilms and promoted the accumulation of NPN and PI within the inner and outer membranes of bacteria to increase membrane permeability, thereby causing membrane damage. This novel contribution toward the antibacterial mechanisms of action of D. gilletii extracts against Shigella species substantiates the use of this plant in the traditional treatment of infectious diarrhoea. Full article

A solvate cocrystal of the antimicrobial norfloxacin (NFX) was formed by using isonicotinamide (INA) as a coformer with the solvent evaporation technique. The cocrystal formation was confirmed by performing solid-state characterization techniques. We evaluated the dissolution under supersaturated conditions and also the solubility at the vertex of triphasic domain of cocrystal and NFX in both water and Fasted-State Simulated Intestinal Fluid (FaSSIF). The antimicrobial activity was evaluated using the microdilution technique. The cocrystal showed 1.8 times higher dissolution than NFX in water at 60 min and 1.3 times higher in FaSSIF at 180 min in the kinetic study. The cocrystal also had an increase in solubility of 8.38 times in water and 6.41 times in FaSSIF. The biopharmaceutical properties of NFX with cocrystallization improved antimicrobial action, as shown in the results of minimum inhibitory concentration (MIC) and inhibitory concentrations of 50% (IC50%) and 90% (IC90%). This paper presents, for the first time, a more in-depth analysis of the cocrystal of NFX–INA concerning its dissolution, solubility, and antimicrobial activity. In all these criteria, the cocrystal obtained better results compared to the pure drug. Full article

The Antifungal Susceptibility Testing method of the European Committee on Antimicrobial Susceptibility Testing (EUCAST-AFST) is a reference technique for the determination of the Minimum Inhibitory Concentration (MIC) of antifungals for Aspergillus fumigatus. However, it is time-consuming and requires expertise. Micronaut-AM (M-AM) is a fast, simple, time-saving, and ready-to-use new colorimetric method using an indicator (resazurin) to facilitate the visual reading. The aim of this retrospective study was to evaluate the performance of the M-AM system and compare it with the EUCAST broth microdilution reference method to determine the susceptibility of 77 A. fumigatus clinical strains to amphotericin B, itraconazole, voriconazole, and posaconazole. Overall, the essential agreements within ±2 dilutions were 100%, 62%, 58%, and 30% and the categorical agreements were 100%, 97%, 91%, and 87% for amphotericin B, itraconazole, voriconazole, and posaconazole, respectively. No categorical discrepancy was found for amphotericin B, but several categorical discordances were observed with azole antifungals. However, only 2 of the 16 azole-resistant strains confirmed by the cyp51A sequencing would have been misclassified by M-AM. The use of M-AM is probably suitable for the determination of the MICs of amphotericin B, but further evaluations are needed to confirm its usefulness for the determination of the MICs of azoles for A. fumigatus. Full article

The aim of this study was to evaluate the inhibitory activity of the commercially available essential oils of Mentha spicata (spearmint) and Eucalyptus globulus (eucalyptus) on Streptococcus mutans ATCC 25175 biofilms in vitro, emulating dental plaque conditions. The composition of the essential oils (EOs) was determined using gas chromatography coupled with mass spectrometry (GC-MS), with the main metabolites being Carvone (57.93%) and Limonene (12.91%) for Mentha spicata and 1,8-Cineole (Eucalyptol) (65.83%) for Eucalyptus globulus. The inhibitory activity was evaluated using the methods of agar-well diffusion and colorimetric microdilution. The inhibition halos were 18.3 ± 0.47 mm and 27.0 ± 0.82 mm, and the MICs were 1.8484 mg/mL and 1.9168 mg/mL for the EOs of Mentha spicata and Eucalyptus globulus, respectively. The activity against the biofilms was evaluated on a substrate of bovine enamel pieces using a basal mucin medium (BMM) in anaerobic conditions with daily sucrose exposition cycles in order to emulate oral cavity conditions. The EOs were applied in a concentration of 0.5% in a sterile saline vehicle with 1% polysorbate 20. After 72 h of cultivation, a significant reduction was observed (p < 0.001%) on the biofilm biomass, which was evaluated by its turbidity in suspension and using a count of the recoverable organisms with regards to the control. The effects of the Eos were not significantly distinct from each other. The EOs showed antimicrobial activity against both the Streptococcus mutans planktonic and biofilm cultures. Thus, EOs may have great potential for the development of pharmaceutical and sanitary products for oral health. Full article

The relation between antifungal susceptibility and treatment outcomes is not well-characterized. There is paucity of surveillance data for cerebrospinal fluid (CSF) isolates of cryptococcus investigated with YEASTONE colorimetric broth microdilution susceptibility testing. A retrospective study of laboratory-confirmed cryptococcus meningitis (CM) patients was conducted. The antifungal susceptibility of CSF isolates was determined using YEASTONE colorimetric broth microdilution. Clinical parameters, CSF laboratory indices, and antifungal susceptibility results were analyzed to identify risk factors for mortality. High rates of resistance to fluconazole and flucytosine were observed in this cohort. Voriconazole had the lowest MIC (0.06 µg/mL) and lowest rate of resistance (3.8%). In a univariate analysis, hematological malignancy, concurrent cryptococcemia, high Sequential Organ Failure Assessment (SOFA) score, low Glasgow coma scale (GCS) score, low CSF glucose level, high CSF cryptococcal antigen titer, and high serum cryptococcal antigen burden were associated with mortality. In a multivariate analysis, meningitis with concurrent cryptococcemia, GCS score, and high CSF cryptococcus burden, were independent predictors of poor prognosis. Both early and late mortality rates were not significantly different between CM wild type and non-wild type species. Full article