Comparative study of a liposome and emulsion system with cinnamon essential oil on the quality and proteolysis of refrigerated minced pork.

Essential oils have been recognized for their strong antibacterial property, making them an innovative approach for preserving meat. However, their chemical instability and direct impact on meat proteins limit their application. To overcome these limitations, various loading systems have been explored. This study aimed to compare the effect of cinnamon essential oil (CEO) loaded in a liposome and emulsion system on the proteolysis of minced pork and to evaluate the advantages of each delivery system in preventing microorganism-induced quality deterioration of meat. Minced pork treated with CEO-liposomes exhibited lower pH, total volatile basic nitrogen (TVB-N), and total viable count (TVC) values than CEO-emulsions and provided better protection against microorganisms. SDS-polyacrylamide gel electrophoresis (PAGE) analysis confirmed that CEO-liposome was more effective in protecting proteins from degradation. Moreover, CEO-liposome produced lower amount of bitter amino acids and harmful biogenic amines. Antibacterial mechanisms indicated that CEO-liposome exhibited a stronger inhibitory effect against major spoilage bacteria in meat products by increasing cell membrane permeability. The membrane damage was further supported by an increase in conductivity and the leakage of nucleic acids. Compared to the CEO-emulsion system, CEO-liposome emerged as an effective preservative for minced pork. These results provided important theoretical support for using a bioactive compound delivery system to prevent microorganism-induced quality deterioration in meat.

Enhanced in vitro bioavailability of resveratrol-loaded emulsion stabilized by ß-lactoglobulin-catechin with excellent antioxidant activity.

The study aimed to fabricate ß-Lactoglobulin-catechin (ß-La-Ca) conjugates as a natural designed antioxidant emulsifier to improve the physicochemical stability of resveratrol emulsion delivery system. Fourier transform infrared (FT-IR) and fluorescence spectroscopy analysis confirmed the formation of conjugates using free radical grafting. The antioxidant ability of emulsion was evaluated by DPPH scavenging activities and ORAC experiments. The emulsion stabilized by ß-La-Ca conjugates exhibited strong antioxidant activity with ORAC value of 2541.39 ± 29.58 µmol TE/g, which was significantly higher than that by ß-Lactoglobulin alone with 387.96 ± 23.45 µmol TE/g or their mixture with 948.23 ± 32.77 µmol TE/g. During the whole simulated gastrointestinal digestion, emulsion stabilized by ß-La-Ca conjugates exhibited excellent oxidative stability that the lipid was mainly digested in the small intestine. This behavior attributed to the greater stability of resveratrol to chemical transformation leading to a higher overall bioavailability in vivo. These results suggested that the ß-La-Ca conjugates could be used to fabricate the emulsion-based delivery system to improve the oxidative stability and bioavailability of chemically labile hydrophobic bioactive compounds.

Potential Anti-Gouty Arthritis of Citronella Essential Oil and Nutmeg Essential Oil through Reducing Oxidative Stress and Inhibiting PI3K/Akt/mTOR Activation-Induced NLRP3 Activity.

Citronella and Nutmeg are two common spices used for seasoning and medicinal purposes, both of which have significant economic value. This study aimed to investigate whether Citronella essential oil and Nutmeg essential oil (NEO) can ameliorate monosodium urate (MSU)-induced gouty arthritis in rats and the potential mechanisms. The results showed that CEO and NEO reduced swelling and redness at joint sites, inhibited neutrophil infiltration, and limited proinflammatory mediator secretion in mice with MSU-induced gouty arthritis. Based on the results of network pharmacology, molecular docking, and western blotting, CEO and NEO may exert anti-gouty arthritis effects by reducing the expression of reactive oxygen species and oxidative stress and downregulating the phosphorylation of the PI3K/AKT/mTOR signaling pathway, thereby inhibiting the production of the NLRP3 inflammasome and inhibiting the production of inflammatory cytokines. Therefore, these two essential oils show potential for use as adjuvant treatments for gouty arthritis in specific aromatherapy products or food seasonings.

Trans-cinnamaldehyde fumigation inhibits Escherichia coli by affecting the mechanism of intracellular biological macromolecules.

This study aimed to determine the antibacterial mechanism of cinnamaldehyde fumigation in Escherichia coli (E. coli). Through vapour fumigation, cinnamaldehyde was confirmed to exhibit effective antibacterial activity against E. coli. The minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) were 0.25 µL/mL and 0.5 µL/mL, respectively. Based on transmission electron microscopy, the wrinkled bacterial cells observed after fumigation could be related to the leakage of intracellular substances. Laser tweezers Raman spectroscopy revealed changes in the main chain of proteins, the hydrogen bond system and spatial structure, and single- and double-stranded DNA breaks. In addition, breakage of the fatty acyl chain backbone was found to affect the vertical order degree of the lipid bilayer and cell membrane fluidity, thereby inhibiting the growth of E. coli. Overall, our findings indicate that cinnamaldehyde fumigation inhibits E. coli growth by inducing changes in intracellular biological macromolecules.

Study on the formation and anti-biofilm properties of cinnamon essential oil inclusion complexes by the structure of modified ß-cyclodextrins.

Essential oils (EOs), which are plant-oriented anti-biofilm agents, are extensively encapsulated by cyclodextrins to overcome their aqueous solubility and chemical instability, and achieve slow release during long-term storage. However, the biological activities of EOs decreased after initial encapsulation in CDs. In this study, modified-ß-cyclodextrins (ß-CDs) were screened as wall materials to maintained the initial anti-biofilm effect of pure CEO. The inhibitory and bactericidal activities of CEO encapsulated in five types of ß-CDs with different substituents (primary hydroxyl, maltosyl, hydroxypropyl, methyl, and carboxymethyl) against Staphylococcus aureus biofilm were evaluated. Crystal violet assay and 3D-View observations suggested that CEO and its inclusion complexes (CEO-ICs) inhibited Staphylococcus aureus biofilm formation through the inhibition of colonising spreading, exopolysaccharide synthesis, and cell surface properties. Molecular docking revealed the causes of the decrease in the anti-biofilm effect after encapsulation, and quantitative structure-activity relationship assays provided MIC and MBIC prediction equation for modified-ß-cyclodextrins inclusion complexes. Maltosyl-ß-CD was screened as the best wall material to retained the anti-biofilm activities as pure cinnamon essential oil in initial stage, and its inclusion complexes can effectively inhibited biofilm formation in milk. This study provides a theoretical guidance for the selection ß-CDs to encapsulate CEO as plant-oriented anti-biofilm agents to inhibit bacterial biofilm formation.

Enhanced mechanical and functional properties of chitosan/polyvinyl alcohol/hydroxypropyl methylcellulose/alizarin composite film by incorporating cinnamon essential oil and tea polyphenols.

In this study, cinnamon essential oil and tea polyphenols were added to chitosan/ polyvinyl alcohol/ hydroxypropyl methylcellulose/ alizarin composite films to enhance their mechanical and functional properties. Their addition to the composite films enhanced their antibacterial and antioxidant properties and significantly improved its elongation at break (p < 0.05). Cinnamon essential oil reduced the water vapor permeability, water content, and water solubility of composite films and improved their transparency. The composite films with additive exhibited excellent UV-barrier ability and pH responsivity. Fourier Transform infrared spectroscopy and X-Ray Diffraction analyses confirmed hydrogen bond formation between the polymer molecules and additives. The results of Scanning Electron Microscope-Focused Ion Beam revealed improved surface and cross-section morphology of the films, leading to the generation of a cross-linked structure. Thermogravimetric and differential scanning calorimetry analysis indicated enhanced thermal stability of the composite films upon cinnamon essential oil addition. Analysis of storage quality indicators (TBARS value, TVC, and TVB-N) revealed that the composite films could prolong the freshness of surimi. The incorporation of cinnamon essential oil and tea polyphenols into the composite films has demonstrated significant potential as an effective and natural alternative for active food packaging.

Host-Guest Assembly-Crosslinked Nanoemulsions with Dual-Antimicrobial Mechanism for Treating Multidrug-Resistant Bacterial Biofilms.

Plant essential oils have good antimicrobial properties, but their poor stability and compatibility in aqueous solutions greatly limit their practical application. To address this issue, a dynamically crosslinked nanoemulsion based on host-guest assembly was developed in this study. First, a ß-cyclodextrin-functionalized quaternary ammonium surfactant (ß-CD-QA) and adamantane-terminated polyethylene glycol (APA) crosslinker were first synthesized. Then, the oil-in-water host-guest crosslinked nanoemulsions (HGCTNs) were formed by incorporating tea tree essential oils (TTO) as a natural antimicrobial agent. The results showed that HGCTNs significantly improved the stability of the essential oil nanoemulsions and extended their shelf life. Furthermore, HGCTNs demonstrated effective antimicrobial properties against both Gram-negative/positive bacterioplankton and bacterial biofilms. The results of antibacterial experiments showed that the dynamically crosslinked HGCTNs exhibit superior antibacterial efficacy, with a minimum inhibitory concentration (MIC) of 12.5 v/v % (0.13 µL/mL TTO) and could eradicate the biofilms. The electrical conductivity of the bacterial solution gradually increased within 5 h of treatment with the nanoemulsions, indicating that the HGCTNs have a slow-release effect of TTO and sustainable antibacterial ability. The antimicrobial mechanism can be attributed to the synergistic antibacterial action of the ß-CD-QA surfactant containing a quaternary ammonium moiety and TTO, which are stabilized by nanoemulsions.

Study of antimicrobial activity and mechanism of vapor-phase cinnamaldehyde for killing Escherichia coli based on fumigation method.

The vapor-phase antibacterial activity of essential oils makes them suitable for applications in air disinfection and other fields. At present, vapor-phase antibacterial activity of plant-based essential oils has rarely been reported. Herein, we report a new approach to investigate the antimicrobial activity and mechanism of vapor-phase cinnamaldehyde using Escherichia coli (E. coli) and three other pathogenic bacteria (Pseudomonas aeruginosa, Salmonella, Staphylococcus aureus) as model bacteria. Plate fumigation and agar block transfer techniques were used to determine the antimicrobial activities of vapor-phase cinnamaldehyde fumigation on the four types of bacteria, and the mechanism of action was determined by electrical conductivity (EC), OD260nm measurement, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and fluorescence spectroscopy. Cinnamaldehyde had good vapor-phase antibacterial activity against the four types of bacteria. The TEM, EC, and OD260nm measurements showed that after fumigation with cinnamaldehyde, the ultrastructures of the cells were damaged, and plasmolysis, cell collapse, and leakage of intracellular substances were observed. The FTIR and fluorescence spectroscopy analyses showed that the secondary and tertiary structures of bacterial membrane proteins were altered. These findings indicate that the cell membrane is an important target for plant-based essential oils to exert their vapor-phase antimicrobial effects. The results showed that plant-based essential oils can be developed as volatile broad-spectrum disinfection products and vapor-phase antiseptics.

Preparation and antibacterial and antioxidant ability of ß-cyclodextrin complexes of vaporized Illicium verum essential oil.

Compared with traditional liquid-liquid embedding method and solid-liquid embedding method of inclusion complexes of ß-cyclodextrin (ß-CD) inclusion of essential oil to form stable properties, the gas-liquid embedding method was applied to encapsulate vaporized illicium verum essential oil (IvEO), with ß-CD as wall materials so that core and wall materials molecules are in active state during complexing process. At optimal conditions with a mass ratio of 1:10, temperature of 80°C, time of 1 h, the ß-CD-IvEO inclusion complexes (ß-CD-IvEO-ICs) had an encapsulation efficiency (EE) of 84.55 ± 2.31%. Fourier transform infrared spectroscopy (FTIR) revealed the encapsulation of IvEO into inclusion complexes, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) demonstrated the enhanced thermal stability of IvEO after embedding. Furthermore, the reducing power and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO)-scavenging capacity displayed certain capacity of antioxidation in a short time but stronger antioxidative activities as reaction time was extended. The diameter of growth zone (DGZ) indicated stronger antibacterial activity of ß-CD-IvEO-ICs against Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, and Staphylococcus aureus. Moreover, the ß-CD-IvEO-ICs could induce the bacteria producing more reactive oxygen species (ROS) than IvEO, resulting in bacterial death.

Injectable thermo-sensitive and wide-crack self-healing hydrogel loaded with antibacterial anti-inflammatory dipotassium glycyrrhizate for full-thickness skin wound repair.

Severe skin injuries are hard to repair and susceptible to bacterial infection. Development of a versatile antimicrobial anti-inflammatory hydrogel dressing that eliminates concern over antibiotic resistance is urgently needed but remains an elusive goal. Our research, described herein, the design and fabrication of a new family of supramolecular hydrogels based on hydroxypropyl chitosan (HPCS) and poly(N-isopropylacrylamide) (PNIPAM) may prove to be that goal. Employing the reversible cross-linking by ß-cyclodextrin (ß-CD) and adamantyl (AD) pre-assembly, the hydrogels can be formed in a facile one-pot method. Additionally, the structure and performance of the hydrogels can be controlled by a simple adjustment of the AD content. The obtained hydrogels exhibit an abundance of desired properties; they are injectable, thermosensitive, highly ductile, self-healable (will self-heal recurring damage to the hydrogel bandage of up to several millimeters wide), biocompatible, and have antimicrobial activity against Staphylococcus aureus when infused with dipotassium glycyrrhizinate (DG). Using a mouse full-thickness skin defect model, in vivo wound healing evaluations revealed that the DG-loaded hydrogels (HP-3/DG10) applied to the wound resulted in rapid wound closure. The hydrogels promoted efficient tissue remolding, collagen deposition, decreased inflammation and performed better than the control groups of commercial TegadermTM film and 3M dressing. Given their multifunctionality and in vivo efficacy, the DG-loaded HP hydrogels hold great potential as a wound dressing for full-thickness skin repair. STATEMENT OF SIGNIFICANCE: Injectable hydrogels are receiving increasing attention as an ideal wound dressing. To the best of our knowledge, however, injectable and wide-crack self-healing hydrogel dressings have been hardly studied. A versatile antimicrobial hydrogel without drug resistance or cytotoxicity is also highly required. Therefore, in the present study, we constructed injectable thermosensitive and wide-crack self-healing hydrogels with antibacterial and anti-inflammatory properties. These hydrogels were developed through novel strategies of the wide-crack self-healing design and the loading of the bioactive antibacterial and anti-inflammatory agent dipotassium glycyrrhizinate. The simple preparation method and multifunctionality of the studied hydrogel composites may provide important insights for the development of future biomaterials for wound dressings and other biomedical applications.

Encapsulation Efficiency and Functional Stability of Cinnamon Essential Oil in Modified ß-cyclodextrins: In Vitro and In Silico Evidence.

Essential oils (EOs) have good natural antioxidant and antimicrobial properties; however, their volatility, intense aroma, poor aqueous solubility, and chemical instability limit their applications in the food industry. The encapsulation of EOs in ß-cyclodextrins (ß-CDs) is a widely accepted strategy for enhancing EO applications. The complexation of cinnamon essential oil (CEO) with five types of ß-CDs, containing different substituent groups (ß-CD with primary hydroxyl, Mal-ß-CD with maltosyl, CM-ß-CD with carboxymethyl, HP-ß-CD with hydroxypropyl, and DM-ß-CD with methyl), inclusion process behaviors, volatile components, and antioxidant and antibacterial activities of the solid complexes were studied. The CEOs complexed with Mal-ß-CD, CM-ß-CD, and ß-CD were less soluble than those complexed with DM-ß-CD and HP-ß-CD. Molecular docking confirmed the insertion of the cinnamaldehyde benzene ring into various ß-CD cavities via hydrophobic interactions and hydrogen bonds. GC-MS analysis revealed that HP-ß-CD had the greatest adaptability to cinnamaldehyde. The CEO encapsulated in ß-, Mal-ß-, and CM-ß-CD showed lower solubility but better control-release characteristics than those encapsulated in DM- and HP-ß-CD, thereby increasing their antioxidant and antibacterial activities. This study demonstrated that ß-, Mal-ß-, and CM-ß-CD were suitable alternatives for the encapsulation of CEO to preserve its antioxidant and antibacterial activities for long-time use.

Can internal mammary lymph nodes irradiation bring survival benefits for breast cancer patients? A systematic review and meta-analysis of 12,705 patients in 12 studies.

OBJECTIVE: To evaluate the effect of prophylactic irradiation of internal mammary lymph nodes in breast cancer patients. METHODS: The computer searched PubMed, EMBASE, Web of science, CNKI, Wanfang Medical Network, the Chinese Biomedical Literature Database to find clinical studies on internal mammary lymph node irradiation (IMNI) in breast cancer. The quality of the included literature was evaluated according to the Newcastle-Ottawa scale. Stata14 software was used for meta-analysis. RESULTS: A total of 12,705 patients in 12 articles were included for meta-analyzed. Compared with patients who unirradiated internal mammary lymph nodes (non-IMNI), the risk of death for patients after IMNI was reduced by 11% (HR 0.89, 95% CI 0.79-1.00, P = 0.0470); DFS of group mixed N+ patients (high risk group) was significantly improved after IMNI (HR 0.58, 95% CI 0.49-0.69, P < 0.001). Further subgroup analysis shows that compared with non-IMNI, DFS was significantly increased in N1or ypN1 subgroup (HR 0.65, 95% CI 0.49-0.87, P = 0.003) and N2or ypN2 subgroup (HR 0.51, 95% CI 0.37-0.70, P < 0.001) after IMNI, but there was no statistical difference in DFS between the IMNI and non-IMNI groups in N0 subgroup (HR 1.02 95% CI 0.87-1.20, P = 0.794) and N3 or ypN3 subgroup (HR 0.85, 95% CI 0.49-1.45, P = 0.547). No serious incidents were reported in all the included studies, and most of the acute and late side effects were mild and tolerable. CONCLUSION: Under modern radiotherapy techniques, IMNI can safely and effectively bring clinical benefits to N1-2 breast cancer patients, but its role in N0, N3 breast cancer patients remains to be further studied.

Physical and oxidative stability of chicken oil-in-water emulsion stabilized by chicken protein hydrolysates.

The emulsifying and antioxidant properties of chicken protein hydrolysates for the physical and oxidative stabilization of chicken oil-in-water emulsion were investigated. The chicken protein pepsin hydrolysates obtained at reaction temperature of 33℃, 1.8% enzyme addition, liquid-solid ratio of 5:1, and reaction time of 4h, showed the DPPH radical scavenging rate of 92.12% and emulsion stability index of 0.07. The hydrolysate exerted significantly improved antioxidant activity and emulsion ability compared to the native chicken protein. The amino acid composition analysis indicated that the contents of hydrophobic amino acids including tyrosine, phenylalanine, and tryptophan were increased after hydrolysis, which contributed to the higher hydrophobicity and antioxidant activity of chicken hydrolysates. The results suggested that the chicken protein hydrolysates could be used as an alternative protein emulsifier for the production of oxidatively stable chicken oil-in-water emulsion.

Mechanisms of vapor-phase antibacterial action of essential oil from Cinnamomum camphora var. linaloofera Fujita against Escherichia coli.

The purpose of this study was to investigate antibacterial activity of essential oil from Cinnamomum camphora var. linaloofera Fujita (EOL) at vapor phase and its mechanism of bactericidal action against Escherichia coli. Results showed that the vapor-phase EOL had significant antibacterial activity with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 200 µl/L. Further analyses showed that treatment of E. coli with vapor-phase EOL resulted in partial degradation of cell membrane, increased membrane permeability, leakage of cytoplasm materials, and prominent distortion and shrinkage of bacterial cells. FTIR showed that EOL altered bacterial protein secondary and tertiary structures. GC/MS analysis showed that the components of vapor-phase EOL included linalool (69.94%), camphor (10.90%), nerolidol (10.92%), and safrole (8.24%), of which linalool had bactericidal activity. Quantum chemical analysis suggested that the antibacterial reactive center of linalool was oxygen atom (O10) which transferred electrons during antibacterial action by the donation of electrons.