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E)ffects of tea tree oil on viability of test organisms. (a) E. coli AG 100: (○) no tea tree oil, and (▪) 0·50% v/v tea tree oil. (b) Staph. aureus NCTC 100: (○) no tea tree oil, (●) 0·25% v/v tea tree oil, and (▪) 0·50% v/v tea tree oil. (c) C. albicans KEM H6:100: (○) no tea tree oil, (●) 0·125% v/v tea tree oil, (□) 0·25% v/v tea tree oil; and (□) 0·50% v/v tea tree oil
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The essential oil of Melaleuca alternifolia (tea tree) exhibits broad-spectrum antimicrobial activity. Its mode of action against the Gram-negative bacterium Escherichia coli AG100, the Gram-positive bacterium Staphylococcus aureus NCTC 8325, and the yeast Candida albicans has been investigated using a range of methods. We report that exposing thes...
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... effects of tea tree oil exposure on the viability of E. coli, Staph. aureus and C. albicans are shown in Fig. 1(a,b,c). Each figure is representative of three separate experiments that gave similar results. At minimum inhibitory and minimum lethal concentrations, E. coli was most susceptible to the effects of tea tree oil, followed by C. albicans and then Staph. ...
Citations
... The enhanced susceptibility of Gram-positive bacteria to essential oils can be attributed to their thicker peptidoglycan layer, which lacks an additional outer membrane barrier. This structural difference makes them more sensitive to the hydrophobic compounds found in essential oils that can disrupt lipid bilayers [47]. In contrast, the resistance of Gram-negative bacteria is likely due to their outer membrane, which is rich in lipopolysaccharides. ...
Helichrysum italicum (immortelle) essential oil is one of the most popular essential oils worldwide and it has many beneficial properties, including antimicrobial. However, in this plant, the chemical diversity of the essential oil is very pronounced. The aim of this work was to process the GC-MS results of four samples of H. italicum essential oil of Serbian origin by chemometric tools, and evaluate the antimicrobial activity in vitro and in silico. Overall, 47 compounds were identified, the most abundant were γ-curcumene, α-pinene, and ar-curcumene, followed by α-ylangene, neryl acetate, trans-caryophyllene, italicene, α-selinene, limonene, and italidiones. Although the four samples of H. italicum essential oil used in this study were obtained from different producers in Serbia, they belong to the type of essential oil rich in sesquiterpenes (γ-curcumene and ar-curcumene chemotype). In vitro antimicrobial potential showed that five were sensitive among ten strains of tested microorganisms: Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Saccharomyces cerevisiae, and Candida albicans. Therefore, these microorganism models were used further for in silico molecular docking through the mechanism of ATP-ase inhibitory activity. Results showed that among all compounds from H. italicum essential oil, neryl acetate has the highest predicted binding energy. Artificial neural network modeling (ANN) showed that two major compounds γ-curcumene and α-pinene, as well as minor compounds such as trans-, and guaiol are responsible for the antimicrobial activity of H. italicum essential oil. The results of this study indicate that H. italicum essential oil samples rich in γ-curcumene, α-pinene, and ar-curcumene cultivated in Serbia (Balkan) have antimicrobial potential both in vitro and in silico. In addition, according to ANN modeling, the proportion of neryl acetate and other compounds detected in these samples has the potential to exhibit antimicrobial activity.
... The Petri dishes are then placed at 4°C for 2 hours, then incubated at 37°C for 24 h. Gentamicin disk was used as a positive control, and DMSO without benzimidazole was also tested [40]. ...
The electrochemical behavior of the biologically active redox chemicals is essential in point of view
antibacterial activity. In some cases, the electronic exchanges are coupled to chemical reactions that produce
new oxidative or reductive species, which might form electrodeposits. This contribution presents a comparative
study of the antibacterial activities and the anodic oxidation of S-triazino-benzimidazole derivatives substituted
at the triazine ring with phenyl, 4-fluorophenyl and pentafluorophenyl groups. By combining bactericidal
screening against E. coli, P. aeruginosa, S. aureus, and S. typhimurium, to a cyclic voltammetry investigation,
it was revealed that the fluorine phenyl substituents in the S-triazine benzimidazole derivatives
enhance the electrons ejection to the platinum disk and the subsequent chemical reactions. Additionally, by
cycling of potential the non-fluorinated chemical produces a rather passive film on the electrode surface,
whereas the fluorinated ones generate electroactive and electrocatalytic coatings. Comparing the results
obtained with S-triazino-benzimidazole derivatives to those with 2-aminobenzimidazole, plausible mechanisms
of their bactericidal action are suggested.
... In general, when a higher volume of essential oil, equivalent to CM (≥25 lL), was added, the antibacterial activity against foodborne bacteria was expected to increase. This is because a larger amount of the hydrophobic essential oil, when added, destroyed and penetrated the lipid structure of the bacterial cell membrane by interacting with phospholipids (Cox et al., 2000). Specifically, more phospholipid was a significant component of the cell membrane structure in Gram-negative bacteria. ...
Rambutan peel (RP), an agricultural by‐product from rambutan trading, contains the red pigment anthocyanin. This research explores developing a colouring agent from RP, utilising cardamom oil (CM) to enhance colour stability, improve antimicrobial functionality, and create a new high‐value red colouring agent from fruit waste. A colouring agent was produced by placing 50 g of RP inside a 1 L glass box, and varying amounts of CM (5 μL, 25 μL, 50 μL, and 100 μL) on filter paper were placed inside the box lid. The box was sealed and left closed for 8 h to allow CM vapour to release onto the surface of RP before being dried at 30 °C and ground into powder. The antibacterial impact of CM‐treated RP on Staphylococcus aureus was assessed using the nutrient broth. The CM‐treated RP powder was used as a food colouring agent in shrimp paste to evaluate the shelf life of shrimp paste during storage at 30 °C. Results revealed that treated RP with 25 μL of CM showed the best red colour appearance in the dried powder. RP with 25 μL of CM exhibited time killing against S. aureus (approximately 4 log10cfu g⁻¹) after being added to the medium for 6 h, disrupting the cell membrane integrity of S. aureus and leading to cell lysis. RP treated with 25 μL of CM also prevented darkening in shrimp paste, maintaining higher values for L* and a*, resulting in increased lightness and a more red appearance. It also inhibited pathogenic bacteria, extending shelf life, and preserving colour stability for 14 days, compared to the control's 7 days. These insights provide valuable guidance for the sustainable utilisation of agricultural waste in the food colouring industry.
... Furthermore, because essential oils dissolve in cell membranes and create membrane swelling, which lowers membrane function, they increase permeability of the membrane (Dorman et al., 2000) Furthermore, essential oils' lipophilic quality, which enables them to permeate cell walls and influence enzymes responsible for cell-wall production, is what gives them their antifungal effect. This changes the morphological features of the fungus (Cox et al., 2000). ...
... Furthermore, because essential oils dissolve in cell membranes and create membrane swelling, which lowers membrane function, they increase permeability of the membrane (Dorman et al., 2000) Furthermore, essential oils' lipophilic quality, which enables them to permeate cell walls and influence enzymes responsible for cell-wall production, is what gives them their antifungal effect. This changes the morphological features of the fungus (Cox et al., 2000). ...
... Furthermore, because essential oils dissolve in cell membranes and create membrane swelling, which lowers membrane function, they increase permeability of the membrane (Dorman et al., 2000) Furthermore, essential oils' lipophilic quality, which enables them to permeate cell walls and influence enzymes responsible for cell-wall production, is what gives them their antifungal effect. This changes the morphological features of the fungus (Cox et al., 2000). ...
... Furthermore, because essential oils dissolve in cell membranes and create membrane swelling, which lowers membrane function, they increase permeability of the membrane (Dorman et al., 2000) Furthermore, essential oils' lipophilic quality, which enables them to permeate cell walls and influence enzymes responsible for cell-wall production, is what gives them their antifungal effect. This changes the morphological features of the fungus (Cox et al., 2000). ...
... Furthermore, because essential oils dissolve in cell membranes and create membrane swelling, which lowers membrane function, they increase permeability of the membrane (Dorman et al., 2000) Furthermore, essential oils' lipophilic quality, which enables them to permeate cell walls and influence enzymes responsible for cell-wall production, is what gives them their antifungal effect. This changes the morphological features of the fungus (Cox et al., 2000). ...
... 9 Additionally, EOs extracted from the tea tree (Melaleuca alternifolia) have been commercially utilized as antiseptics. 6 Many EOs have been employed by different industries in the European Union, including their use in perfumes, pharmaceutical products, and food flavorings and additives. 4,5 Additionally, most EOs have been recognized as Generally encapsulation of different EOs into cyclodextrins, showing more significant antimicrobial activities. ...
The rising risks of food microbial contamination and foodborne pathogens resistance have prompted an increasing interest in natural antimicrobials as promising alternatives to synthetic antimicrobials. Essential oils (EOs) obtained from natural sources have shown promising anticancer, antimicrobial, and antioxidant activities. EOs extracted from the resins of Pistacia lentiscus var. Chia are widely utilized for the treatment of skin inflammations, gastrointestinal disorders, respiratory infections, wound healing, and cancers. The therapeutic benefits of P. lentiscusessential oils (PO) are limited by their low solubility, poor bioavailability, and high volatility. Nanoencapsulation of PO can improve their physicochemical properties and consequently their therapeutic efficacy while overcoming their undesirable side effects. Hence, PO was extracted from the resins of P. lentiscusvia hydrodistillation. Then, PO was encapsulated into (2-hydroxypropyl)-beta-cyclodextrin (HPβCD) via freeze-drying. The obtained inclusion complexes (PO-ICs) appeared as round vesicles (22.62 to 63.19 nm) forming several agglomerations (180 to 350 nm), as detected by UHR-TEM, with remarkable entrapment efficiency (89.59 ± 1.47%) and a PDI of 0.1475 ± 0.0005. Furthermore, the encapsulation and stability of PO-ICs were confirmed via FE-SEM, 1 H NMR, 2D HNMR (NOESY), FT-IR, UHR-TEM, and DSC. DSC revealed a higher thermal stability of the PO-ICs, reaching 351.0°C. PO-ICs exerted substantial antibacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli as compared to free PO. PO-ICs showed significant enhancement in the antibacterial activity of the encapsulated PO against S. aureus with an MIC90 of 2.84 mg/mL and against P. aeruginosa with MIC90 of 3.62 mg/ mL and MIC50 of 0.56 mg/mL. In addition, PO-ICs showed greater antimicrobial activity against E. coli by 6-fold with an MIC90 of 0.89 mg/mL, compared to free PO, which showed an MIC90 of 5.38 mg/mL. In conclusion, the encapsulation of PO into HPβCD enhanced its aqueous solubility, stability, and penetration ability, resulting in a significantly higher antibacterial activity.
... Samples were collected into a sterile sample bottle and sent to the laboratory for further investigation. Analysis was carried out using a commercial diagnostic kit (Milliflex® quantum reader) adjusted at an input power supply of 50-60 Hz, temperature of 40 o C and detection area within the area of 55 mm diameter [32]. ...
... The final volume was immediately increased with 10 ml of distilled water. The absorbance of the reaction mixture at 410 nm was measured with a spectrophotometer and compared to a blank [32]. ...
... Using the gravimetric technique, the alkaloid content of UCLM was determined [32]. Alkaloids were precipitated by mixing 20 ml of acetic acid solution in ethanol (10% w/v) with 0.5 g of UCLM and placing the mixture in a water bath. ...
The purpose of this experiment was to determine how supplementing Uvaria chamae leaf meal affects growth performance and a few hematological markers of broiler chicken. For a 56-day study, 500 one-day-old (Ross 307) broiler chicks were randomly assigned to five treatments, each consisting of 100 birds. Standard feed was formulated according to the nutritional standards for broilers. Treatment 1 (T1) was fed a standard diet with 0.25 g/kg Oxytetracycline while T2, T3, T4, and T5 were provided a standard diet supplemented with Uvaria chamae leaf meal (UCLM) at 5g, 10g, 15g, and 20g, respectively. The treatments had a significant impact on body weight gain (BWG), feed conversion ratio and mortality. In contrast, the mortality rate and Escherichia coli counts were higher in T1 and T2 compared to other groups, whereas BWG was higher in T2, T3, T4, and T5 compared to T1. Regarding crude fiber digestibility and average daily feed intake, there was no statistically significant difference. The dry matter, crude protein, ether extract, ash digestibility, hemoglobin, packed cell volume, red blood cell, lymphocytes, monocytes, immunoglobulin A, Y, and M and Lactobacillus sp counts of the birds supplemented with UCLM at 2 g/kg (T2), 4 g/kg (T3), 6 g/kg (T4), and 8 g/kg (T5) were similar but significantly greater than those of T1 (0.25 g/kg Oxytetracycline). It was determined that broilers' diets can include up to 20 g/kg of UCLM supplementation without harming the birds' health.
