Physical and light oxidative properties of eugenol encapsulated by molecular inclusion and emulsion–diffusion method

Antibacterial effect of protease-responsive cationic eugenol liposomes modified by gamma-polyglutamic acid against Staphylococcus aureus

Eugenol, as a natural antibacterial agent, has been widely studied for its inhibitory effect on the common food-borne pathogen Staphylococcus aureus (S. aureus). However, the widespread application of eugenol is still limited by its instability and volatility. Herein, γ-polyglutamic acid coated eugenol cationic liposomes (pGA-ECLPs) were successfully constructed by self-assembly with an average particle size of 170.7 nm and an encapsulation efficiency of 36.2%. The formation of pGA shell significantly improved the stability of liposomes, and the encapsulation efficiency of eugenol only decreased by 20.7% after 30 days of storage at 4 °C. On the other hand, the pGA layer can be hydrolyzed by S. aureus, achieving effective control of release through response to bacterial stimuli. The application experiments further confirmed that pGA-ECLPs effectively prolonged the antibacterial effect of eugenol in fresh chicken without causing obvious sensory effects on the food. The above results of this study provide an important reference for extending the action time of natural antibacterial substances and developing new stimuli-responsive antibacterial systems.

Innovative Encapsulation Strategies for Food, Industrial, and Pharmaceutical Applications

Bioactive metabolites obtained from fruits and vegetables as well as many drugs have various capacities to prevent or treat various ailments. Nevertheless, their efficiency, in vivo, encounter many challenges resulting in lower efficacy as well as different side effects when high doses are used resulting in many challenges for their application. Indeed, demand for effective treatments with no or less unfavorable side effects is rising. Delivering active molecules to a particular site of action within the human body is an example of targeted therapy which remains a challenging field. Developments of nanotechnology and polymer science have great promise for meeting the growing demands of efficient options. Encapsulation of active ingredients in nano-delivery systems has become as a vitally tool for protecting the integrity of critical biochemicals, improving their delivery, enabling their controlled release and maintaining their biological features. Here, we examine a wide range of nano-delivery techniques, such as niosomes, polymeric/solid lipid nanoparticles, nanostructured lipid carriers, and nano-emulsions. The advantages of encapsulation in targeted, synergistic, and supportive therapies are emphasized, along with current progress in its application. Additionally, a revised collection of studies was given, focusing on improving the effectiveness of anticancer medications and addressing the problem of antimicrobial resistance. To sum up, this paper conducted a thorough analysis to determine the efficacy of encapsulation technology in the field of drug discovery and development.

Antimicrobial Activities of Pistacia lentiscus Essential Oils Nanoencapsulated into Hydroxypropyl-beta-cyclodextrins

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, 1H 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.

Improved antimicrobial activities of Boswellia sacra essential oils nanoencapsulated into hydroxypropyl-beta-cyclodextrins

Natural antimicrobials have recently gained increasing interest over synthetic antimicrobials to overcome foodborne pathogens and food microbial contamination. Essential oils (EOs) obtained from Boswellia sacra resins (BO) were utilized for respiratory disorders, rheumatoid arthritis, malignant tumors, and viral infections. Like other EOs, the therapeutic potential of BO is hindered by its low solubility and bioavailability, poor stability, and high volatility. Several studies have shown excellent physicochemical properties and outstanding therapeutic capabilities of EOs encapsulated into various nanocarriers. This study extracted BO from B. sacra resins via hydrodistillation and encapsulated it into hydroxypropyl-beta-cyclodextrins (HPβCD) using the freeze-drying method. The developed inclusion complexes of BO (BO-ICs) had high encapsulation efficiency (96.79 ± 1.17%) and a polydispersity index of 0.1045 ± 0.0006. BO-ICs showed presumably spherical vesicles (38.5 to 59.9 nm) forming multiple agglomerations (136.9 to 336.8 nm), as determined by UHR-TEM. Also, the formation and stability of BO-ICs were investigated using DSC, FTIR, FE-SEM, UHR-TEM, 1H NMR, and 2D HNMR (NOESY). BO-ICs showed greater thermal stability (362.7 °C). Moreover, compared to free BO, a remarkable enhancement in the antimicrobial activities of BO-ICs was shown against three different bacteria: Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. BO-ICs displayed significant antibacterial activity against Pseudomonas aeruginosa with an MIC90 of 3.93 mg mL-1 and an MIC50 of 0.57 mg mL-1. Also, BO-ICs showed an increase in BO activity against Escherichia coli with an MIC95 of 3.97 mg mL-1, compared to free BO, which failed to show an MIC95. Additionally, BO-ICs showed a more significant activity against Staphylococcus aureus with an MIC95 of 3.92 mg mL-1. BO encapsulation showed significantly improved antimicrobial activities owing to the better stability, bioavailability, and penetration ability imparted by encapsulation into HPβCD.

Protein and polysaccharide based encapsulation of ginger oleoresin: impact of wall materials on powder stability, release rate and antimicrobial characteristics

Ginger oleoresin is widely used as a flavouring agent in many foods. But its bioactive components are unstable as being sensitive to heat, humidity and light. Hence this study proposes the encapsulation of ginger oleoresin in order to protect it and regulate its release in the gastrointestinal system via spray drying utilising whey protein isolate (WPI) and gum Acacia (GA) as wall materials. The feed emulsions used were characterised for emulsion stability, viscosity, droplet size and thermal properties. The GA microcapsules had a substantially greater mean particle diameter (1980 nm) than WPI microcapsules (1563 nm). The WPI microcapsules retained high content of 6-and 8-gingerol (89.57 and 12.54 mg g-1) compared to GA. The WPI microcapsules showed the largest mean inhibition zone with diameter of 16.64 mm against Escherichia coli and 22.68 mm against Staphylococcus aureus making them most effective in preventing the growth of test bacteria. Both WPI and GA microcapsules exhibited zeta potential value in the range of (-21.09 to -27.35 mV) indicating excellent colloidal stability. The highest concentration of antioxidant activity (73.33 %) and total phenols (33.92 mg g-1) was retained by WPI microcapsules in intestinal juice which ensures intestinal regulatory release.

Development of poly(hydroxybutyrate) film incorporated with nano silica and clove essential oil intended for active packaging of brown bread

The objective of current study was to develop Poly(hydroxybutyrate) (PHB) based active packaging film with long lasting antimicrobial potential in food-packaging applications. For developing such films, PHB was incorporated with poly(ethylene glycol) (PEG) as a plasticizer, nano-silica (n-Si) as strengthening material and clove essential oil (CEO) as an antimicrobial agent. These solvent-casted films with varying concentration of n-Si (0.5, 1, 1.5, 2 %) and 30 % CEO of total polymer matrix weight i.e., PHB/PEG (90/10) were prepared and studied on the basis of morphological, mechanical, thermal, degradation and antimicrobial behaviours. The presence of CEO and n-Si was confirmed by Fourier transform infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to investigate homogeneous dispersal of n-Si in polymer matrix. PHB/PEG/CEO/Si 1.0 film was selected as optimized one after mechanical testing and therefore further carried for antimicrobial testing. This selected film extended the shelf-life of brown bread up to 10 days comparable to bread wrapped in polyethylene. This revealed that PHB/PEG/CEO/Si 1.0 exhibited superior antibacterial activity against the food borne microbes i.e., Escherichia coli, Staphylococcus aureus and Aspergillus niger. Our findings indicate that this film improved the shelf-life of packaged bread and has promising features for active food packaging.

Protection and Disinfection Activities of Oregano and Thyme Essential Oils Encapsulated in Poly(ε-caprolactone) Nanocapsules

The biocolonization of building materials by microorganisms is one of the main causes of their degradation. Fungi and bacteria products can have an undesirable impact on human health. The protection and disinfection of sandstone and wood materials are of great interest. In this study, we evaluated the protection and disinfection activity of oregano and thyme essential oils encapsulated in poly(ε-caprolactone) nanocapsules (Or-NCs, Th-NCs) against four types of environmental microorganisms: Pleurotus eryngii, Purpureocillium lilacinum (fungal strains), Pseudomonas vancouverensis, and Flavobacterium sp. (bacterial strains). The surfaces of sandstone and whitewood samples were inoculated with these microorganisms before or after applying Or-NCs and Th-NCs. The concentration-dependent effect of Or-NCs and Th-NCs on biofilm viability was determined by the MTT reduction assay. The results showed that Or-NCs and Th-NCs possess effective disinfection and anti-biofilm activity. Diffuse reflectivity measurements revealed no visible color changes of the materials after the application of the nanoencapsulated essential oils.

Nano-vesicular carriers for bioactive compounds and their applications in food formulations

The most commonly used vesicular systems in the food industry include liposomes, niosomes, phytosomes, or transfersomes. This review focuses on showing how nano-vesicular carriers (NVCs) amend the properties of bioactive compounds (bioactives), making them suitable for food applications, especially functional foods. In this research, we elaborate on the question of whether bioactive-loaded NVCs affect various food aspects such as their antioxidant capacity, or sensory properties. This review also shows how NVCs improve the long-term release profile of bioactives during storage and at different pH values. Besides, the refinement of digestibility and bioaccessibility of diverse bioactives through NVCs in the gastrointestinal tract is elucidated. NVCs allow for stable vesicle formation (e.g. from anthocyanins) which reduces their cytotoxicity and proliferation of cancer cells, prolongs the release bioactives (e.g. d-limonene) with no critical burst, reduces the biofilm formation capacity of both Gram-positive/negative strains and their biofilm gene expression is down-regulated (in the case of tannic acid), low oxidation (e.g. iron) is endured when exposed to simulated gastric fluid, and unpleasant smell and taste are masked (in case of omega-3 fatty acids). After the incorporation of bioactive-loaded NVCs into food products, their antioxidant capacity is enhanced, maintaining high encapsulation efficiency and enduring pasteurization conditions, and they are not distinguished from control samples in sensory evaluation despite the reverse situation about free bioactives.

Nanoparticles Loaded with Essential Oil from Zanthoxylum riedelianum Engl. Leaves: Characterization and Effects on Bemisia tabaci Middle-East Asia Minor 1

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle-East Asia Minor 1 is a major pest of agricultural production systems. It is controlled by synthetic insecticides. Essential oils are promising eco-friendly alternatives. This study developed and characterized nanoparticles loaded with essential oils of Zanthoxylum riedelianum Engl. (Rutaceae) leaves and evaluated their potential for B. tabaci management. The essential oil exhibited an average yield of 0.02% (w w^-1) and showed as major components γ-elemene (24.81%), phytol (18.16%), bicyclogermacrene (16.18%), cis-nerolidol (8.26%), and D-germacrene (6.52%). Characterization of the nanoparticles showed a pH between 4.5 and 6.7, a zeta potential of approximately - 25 mV, particle-size distribution ranging from 450 to 550 nm, and encapsulation efficiency close to 98%. The nanoencapsulation was an efficient process that provided photostability against photodegradation. Bioassays with crude and nanoencapsulated essential oils significantly reduced the number of nymphs and eggs of B. tabaci, with the best results observed at concentrations of 5 and 2% (v v^-1). Our results demonstrated that essential oils from Z. riedelianum can be nanoformulated resulting in a stable product while maintaining their biological activity against B. tabaci Middle-East Asia Minor 1.

Nanomedicine as an Emerging Technology to Foster Application of Essential Oils to Fight Cancer

Natural prodrugs extracted from plants are increasingly used in many sectors, including the pharmaceutical, cosmetic, and food industries. Among these prodrugs, essential oils (EOs) are of particular importance. These biologically active volatile oily liquids are produced by medicinal and aromatic plants and characterized by a distinctive odor. EOs possess high anticancer, antibacterial, antiviral, and antioxidant potential but often are associated with low stability; high volatility; and a high risk of deterioration with exposure to heat, humidity, light, or oxygen. Furthermore, their bioavailability is limited because they are not soluble in water, and enhancements are needed to increase their potential to target specific cells or tissues, as well as for controlled release. Nanomedicine, the application of nanotechnology in medicine, may offer efficient solutions to these problems. The technology is based on creating nanostructures in which the natural prodrug is connected to or encapsulated in nanoparticles or submicron-sized capsules that ensure their solubility in water and their targeting properties, as well as controlled delivery. The potential of EOs as anticancer prodrugs is considerable but not fully exploited. This review focusses on the recent progress towards the practical application of EOs in cancer therapy based on nanotechnology applications.

Microencapsulation of Natural Food Antimicrobials: Methods and Applications

The global demand for safe and healthy food with minimal synthetic preservatives is continuously increasing. Some natural food antimicrobials with strong antimicrobial activity and low toxicity have been considered as alternatives for current commercial food preservatives. Nonetheless, these natural food antimicrobials are hardly applied directly to food products due to issues such as food flavor or bioavailability. Recent advances in microencapsulation technology have the potential to provide stable systems for these natural antibacterials, which can then be used directly in food matrices. In this review, we focus on the application of encapsulated natural antimicrobial agents, such as essential oils, plant extracts, bacteriocins, etc., as potential food preservatives to extend the shelf-life of food products. The advantages and drawbacks of the mainly used encapsulation methods, such as molecular inclusion, spray drying, coacervation, emulsification, supercritical antisolvent precipitation and liposome and alginate microbeads, are discussed. Meanwhile, the main current applications of encapsulated antimicrobials in various food products, such as meat, dairy and cereal products for controlling microbial growth, are presented.

Comparative evaluation of carvacrol and eugenol chitosan nanoparticles as eco-friendly preservative agents in cosmetics

The current status of controversy regarding the use of certain preservatives in cosmetic products makes it necessary to seek new ecological alternatives that are free of adverse effects on users. In our study, two different natural terpenes Carvacrol and Eugenol were encapsulated in chitosan nanoparticles in different ratios of Chitosan:terpene. The nanoparticles were characterized by DLS and TEM showing a maximum particle size of 100 nm. The chemical structure, thermal properties, and release profile of terpenes were evaluated showing a successful protection of terpene in Chitosan matrix. Two different release profile were observed showing a faster release profile in the case of Eugenol. Antimicrobial properties of nanoparticles were evaluated against typical microbial contaminants found in cosmetic products, showing higher antimicrobial properties with chitosan encapsulation of terpenes. Furthermore, natural moisturizing cream inoculated with beforementioned microorganisms was formulated with Carvacrol-chitosan nanoparticles and Eugenol-chitosan nanoparticles to evaluate the preservative efficiency, indicating a highest preservative efficiency with the use of Eugenol-chitosan nanoparticles.

Antibacterial Effect of Dihydromyricetin on Specific Spoilage Organisms of Hybrid Grouper

This study aimed to investigate the mechanism of antibacterial activity level inhibition of dihydromyricetin (DMY) against specific spoilage bacteria of grouper. Firstly, the specific spoilage bacteria of grouper in the cold storage process are Pseudomonas antarctica (P. antarctica), which are selected by calculating the spoilage metabolite yield factor. It was determined that the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of DMY against grouper spoilage bacteria were 2.0 mg/mL and 6.4 mg/mL, respectively. DMY was added to the matrix of chitosan and sodium alginate, and DMY emulsions of different concentrations (0 MIC, 1 MIC, 2 MIC, 4 MIC) were prepared and characterized by differential calorimetry methods. Through analyzing cell permeability, enzyme activity, and images of the confocal laser scanning microscope (CLSM), we further studied the antibacterial mechanism of DMY emulsion on specific spoilage bacteria. The results showed that, with the increase of DMY concentration in the treatment group, the leakage of nucleic acid and protein increased significantly, the activity of ATPase and three critical enzymes in the Embden-Meyerhof-Parnas (EMP) pathway decreased significantly, and the activity of AKPase did not decrease significantly, . The metabolic activity and viability are reduced considerably. Analysis of the above results shows that DMY inhibits the growth and reproduction of P. antarctica by interfering with the metabolic activity of bacteria and destroying the function of bacterial cell membranes but has no inhibitory effect on the activity of AKPase. This study proves that DMY could be an effective and natural antibacterial agent against specific spoilage bacteria in aquatic products.

Toxicity nanoinsecticide based on clove essential oil against Tribolium castaneum (Herbst)

This study aimed to characterize nanoparticles loaded with clove (Syzygium aromaticum) essential oil-based polyethylene glycol (PEG) and to know their insecticidal activity against red flour beetle (Tribolium castaneum). The nanoparticles have irregular shapes in good dispersion. The nanoformulation could not enhance clove oil contact toxicity to T. castaneum, but could protect the oil from degradation and evaporation while simultaneously allowing sustained release, as indicated by the continued high toxicity for 16 weeks of storage.

Assessment of Fennel Oil Microfluidized Nanoemulsions Stabilization by Advanced Performance Xanthan Gum

In this work, nanoemulsion-based delivery system was developed by encapsulation of fennel essential oil. A response surface methodology was used to study the influence of the processing conditions in order to obtain monomodal nanoemulsions of fennel essential oil using the microchannel homogenization technique. Results showed that it was possible to obtain nanoemulsions with very narrow monomodal distributions that were homogeneous over the whole observation period (three months) when the appropriate mechanical energy was supplied by microfluidization at 14 MPa and 12 passes. Once the optimal processing condition was established, nanoemulsions were formulated with advanced performance xanthan gum, which was used as both viscosity modifier and emulsion stabilizer. As a result, more desirable results with enhanced physical stability and rheological properties were obtained. From the study of mechanical spectra as a function of aging time, the stability of the nanoemulsions weak gels was confirmed. The mechanical spectra as a function of hydrocolloid concentration revealed that the rheological properties are marked by the biopolymer network and could be modulated depending on the amount of added gum. Therefore, this research supports the role of advanced performance xanthan gum as a stabilizer of microfluidized fennel oil-in-water nanoemulsions. In addition, the results of this research could be useful to design and formulate functional oil-in-water nanoemulsions with potential application in the food industry for the delivery of nutraceuticals and antimicrobials.

Eugenol-piperine loaded polyhydroxy butyrate/polyethylene glycol nanocomposite-induced apoptosis and cell death in nasopharyngeal cancer (C666-1) cells through the inhibition of the PI3K/AKT/mTOR signaling pathway

Nasopharyngeal cancer is a malignancy developing from the nasopharynx epithelium due to smoking and nitrosamine-containing foods. Nasopharyngeal cancer is highly endemic to Southeast Asia. Eugenol and piperine have shown many anticancer activities on numerous cancer types, like colon, lung, liver, and breast cancer. In this study, we amalgamated eugenol and piperine loaded with a polyhydroxy butyrate/polyethylene glycol nanocomposite (Eu-Pi/PHB-PEG-NC) for better anticancer results against nasopharyngeal cancer (C666-1) cells. In the current study, nasopharyngeal cancer cell lines C666-1 were utilized to appraise the cytotoxic potential of Eug-Pip-PEG-NC on cell propagation, programmed cell death, and relocation. Eu-Pi/PHB-PEG-NC inhibits cellular proliferation on C666-1 cells in a dose-dependent manner, and when compared with 20 µg/ml, 15 µg/ml of loaded mixture evidently restrained the passage aptitude of C666-1 cells, this was attended with a downregulated expression of mitochondrial membrane potential. Treatment with 15 µg/ml Eu-Pi/PHB-PEG-NC suggestively amplified cell apoptosis in the C666-1 cells. Furthermore, its cleaved caspase-3, 8, and 9 and Bax gene expression was augmented and Bcl-2 gene expression was diminished after Eu-Pi/PHB-PEG-NC treatment. Additionally, our data established that the collective effect of Eu-Pi/PHB-PEG-NC loaded micelles inhibited the expansion of C666-1 cells augmented apoptosis connected with the intrusion of PI3K/Akt/mTOR signaling pathway.

Implementation of the emulsification-diffusion method by solvent displacement for polystyrene nanoparticles prepared from recycled material

From an integral perspective, nanotechnology can be used to care for the environment by improving current preparation methods and facilitating industrial scale-up. This article discusses the implementation of techniques for obtaining polystyrene nanoparticles (PSN), as an added value, using an emulsification and solvent displacement method (EDSD); the solvent displacement is a novel modification to the emulsion-diffusion methodology, where the diffusion is done directly on the emulsion, which allows concentrated dispersions that facilitate direct use to be obtained, eliminating the dilution with water and the recovery of water by additional processes. The solvent was recovered by reduced pressure, which is class 3, conforming to ICH, and making this method sustainable. The optimization of this process has not been reported elsewhere. This approach made it possible to obtain highly-concentrated nanoparticles while allowing the reuse of the solvent. A scaling proposal is presented that integrates the conditioning of the solid urban waste material called expanded polystyrene (EPS) foam that constitutes a serious environmental problem both nationally and globally. Hence, the article presents an alternative to the recycling of EPS, and a methodology in the context of green chemistry, because solvent is recovered to prepare other batches. The PSN obtained from this waste material had a minimum particle size of 225.8 nm, with a polydispersion index of 0.158. Process performance was 97.1%, and the solvent was recovered at a maximum rate of 85%. The morphology of the PSN was spherical and uniform, with a smooth surface.

Antioxidants entrapment in polycaprolactone microparticles using supercritical assisted injection in a liquid antisolvent

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The efficient entrapment of antioxidants in PCL microparticles was obtained.

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Coprecipitates showed slower and controlled dissolution compared to pure compounds.

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Coprecipitation preserved the scavenging activity of the entrapped antioxidants.

In this work, the entrapment of two antioxidants, α-lipoic acid (ALA) and eugenol (EUG), in polycaprolactone (PCL) microparticles, using the supercritical assisted injection in a liquid antisolvent (SAILA), is proposed.

Using SAILA, spherical and non-aggregated PCL particles, with average sizes between 0.2 and 1.2 μm, were produced. Then, coprecipitation experiments were performed: PCL/EUG and PCL/ALA particles with an average size of 0.99 ± 0.34 μm and 0.99 ± 0.18 μm, respectively, were produced, with entrapment efficiencies up to 90 %, considerably higher than results reported in the literature. EUG and ALA coprecipitates showed complete release kinetics in a maximum time of 2 days respect to dissolution time of about 4 h and 5 h of unprocessed EUG and ALA, respectively. Furthermore, the antioxidant power of the used compounds was preserved in the obtained co-precipitates.

Encapsulation of Essential Oils via Nanoprecipitation Process: Overview, Progress, Challenges and Prospects

Essential oils are of paramount importance in pharmaceutical, cosmetic, agricultural, and food areas thanks to their crucial properties. However, stability and bioactivity determine the effectiveness of essential oils. Polymeric nanoencapsulation is a well-established approach for the preservation of essential oils. It offers a plethora of benefits, including improved water solubility, effective protection against degradation, prevention of volatile components evaporation and controlled and targeted release. Among the several techniques used for the design of polymeric nanoparticles, nanoprecipitation has attracted great attention. This review focuses on the most outstanding contributions of nanotechnology in essential oils encapsulation via nanoprecipitation method. We emphasize the chemical composition of essential oils, the principle of polymeric nanoparticle preparation, the physicochemical properties of essential oils loaded nanoparticles and their current applications.

Evaluation of Antitumor Activity and Hepatoprotective Effect of Mitomycin C Solubilized in Chamomile Oil Nanoemulsion

PURPOSE

The present study aimed to investigate the antitumor activity and hepatoprotective effect of the MTC, when combined with CHAM oil nanoemulsion (NE), (CHAM-MTC) on the tumor growth.

MATERIALS/METHODS

The in vitro study assessed the antineoplastic effect of CHAM-MTC on the MCF-7 breast cancer cells while the in vivo therapeutic effectiveness and toxicities of CHAM-MTC were evaluated in Ehrlich Ascites Carcinoma (EAC) bearing mice. One hundred female Swiss albino mice, divided equally into non-EAC group (negative control), untreated EAC group (positive control) and three EAC groups received once intraperitoneal injection of 0.2ml CHAM-NE, 0.2ml Normal Saline (NS) contained MTC (1mg/kg) and 0.2ml CHAM-NE mixed with MTC (1mg/kg), respectively.

RESULTS

The in vitro results indicated that CHAM-NE could potentiate the effect of MTC in sub-effective concentrations since the half-maximal inhibitory concentration (IC50) was reduced by a factor of 21.94 when compared to the MTC-NS. The in vivo study revealed that mice treated with CHAM-MTC showed a significant increase in the median survival time (MST= 37 days) when compared to the MTC-NS treated group (MST= 29.50 days). In addition, CHAM-MTC showed protective ability against the oxidative stress and hepatic damage induced by EAC and MTC treatment.

CONCLUSION

The combination of MTC with CHAM-NE could be valuable in enhancing the therapeutic efficacy of MTC against EAC and in eliminating MTC-induced hepatotoxicity.

A Novel Shell Material-Highland Barley Starch for Microencapsulation of Cinnamon Essential Oil with Different Preparation Methods

Highland barley starch (HBS), as a carbohydrate shell material with excellent performance in microcapsule applications, has rarely been reported. In the present study, three different microcapsules (CEO-SWSM, CEO-PM, and CEO-UM) were synthesized successfully via saturated aqueous solution method, molecular inclusion method and ultrasonic method, respectively, using HBS as shell material coupled with cinnamon essential oil (CEO) as the core material. The potential of HBS as a new shell material and the influence of synthetic methods on the performance of microcapsules, encapsulation efficiency (EE), yield, and release rate of CEO-SWSM, CEO-PM, and CEO-UM were determined, respectively. The results confirmed that CEO-PM had the most excellent EE (88.2%), yield (79.1%), as well as lowest release rate (11.5%, after 25 days of storage). Moreover, different kinetic models were applied to fit the release process of these three kinds of microcapsules: CEO-SWSM, CEO-PM, and CEO-UM had the uppermost R-squared value in the Higuchi model, the zero-order model, and the first-level model, respectively. Over all, this work put forward a novel perspective for the improved encapsulation effect of perishable core materials (e.g., essential oil) for the food industry.

Near-infrared polyfluorene encapsulated in poly(ε-caprolactone) nanoparticles with remarkable large Stokes shift

Near-infrared (NIR) fluorescent dyes have attracted increasing attention as fluorescent probes in biomedical applications due to their low biological autofluorescence as well as high tissue penetration depth. However, their being hydrophobic in nature limits their clinical use as they are prone to aggregate in the physiological environment. Herein, we have designed and synthesized a novel polymeric NIR fluorescent dye and then encapsulated it into a poly(ε-caprolactone) (PCL) matrix by way of an emulsion–diffusion technique. The effect of the structure of the surfactant on the nanoparticle properties is investigated. Results show that polymeric surfactant, Kolliphor® P188, allows the formation of a high fluorescence intensity of the nanoparticles with the highest level homogeneity and stability. The synthesized nanoparticles show significant advantages in terms of a remarkable large stokes shift (276 nm) in the aqueous solution and excellent biocompatibility. The fabrication process is not limited to encapsulation of polymeric fluorescent dye. The synthesized NIR polymeric nanoparticles would be potentially applicable for biomedical applications.

A near-infrared dye encapsulated in poly(ε-caprolactone) nanoparticles have been synthesized. Using Kolliphor® P188 as a surfactant, the stable nanoparticles exhibit strong fluorescence intensity and remarkable large Stokes shift.

Nanoencapsulated essential oils embedded in ice improve the quality and shelf life of fresh whole seabream stored on ice

Ice containing essential oils (EOs) nanoencapsulated in β-cyclodextrins (β-CD) (named as EOs+β-CD ice) was used for stunning/slaughtering by hypothermia in ice slurry, and for ice storage of gilthead seabream. Clove essential oil (CEO) was used at fish stunning/slaughtering, while ice storage of whole fish was performed using a combination of carvacrol, bergamot and grapefruit EOs (CBG). Inclusion complexes CBG+β-CD were characterized, and antimicrobial effect was also evaluated. The kneading method used to form inclusion complexes with CBG showed a good complexation efficiency. Microbial, physical-chemical and sensory analyses were carried out to assess the quality changes of fresh whole seabream during ice storage at 2 °C for 17 days. Results (microbial, chemical and sensorial) indicated that seabream stunning/slaughtering and storage using EOs+β-CD ice (in low doses of 15 mg/kg ice for stunning, and 50 mg/kg ice for ice storage) improved the quality of fresh fish and extended the shelf-life up to 4 days.

Microencapsulation of eucalyptol in polyethylene glycol and polycaprolactone using particles from gas-saturated solutions

Eucalyptol is the natural cyclic ether which constitutes the bulk of terpenoids found in essential oils of Eucalyptus spp. and is used in aromatherapy for treatment of migraine, sinusitis, asthma and stress. It acts by inhibiting arachidonic acid metabolism and cytokine production. Chemical instability and volatility of eucalyptol restrict its therapeutic application and necessitate the need to develop an appropriate delivery system to achieve extended release and enhance its bioactivity. However, the synthesis method of the delivery system must be suitable to prevent loss or inactivation of the drug during processing. In this study, supercritical carbon dioxide (scCO₂) was explored as an alternative solvent for encapsulation and co-precipitation of eucalyptol with polyethylene glycol (PEG) and/or polycaprolactone (PCL) using the particles from gas-saturated solution (PGSS) process. Polymers and eucalyptol were pre-mixed and then processed in a PGSS autoclave at 45 °C and 80 bar for 1 h. The mixture in scCO₂ was micronized and characterized. The presence of eucalyptol in the precipitated particles was confirmed by infrared spectroscopy, gas chromatography and mass spectrometry. The weight ratios of PEG–PCL blends significantly influenced loading capacity and encapsulation efficiency with 77% of eucalyptol encapsulated in a 4 : 1 composite blend of PEG–PCL. The particle size distribution of the PGSS-micronized particles ranged from 30 to 260 μm. ScCO₂ assisted microencapsulation in PEG and PCL reduced loss of the volatile drug during a two-hour vaporization study and addition of PCL extended the mean release time in simulated physiological fluids. Free radical scavenging and lipoxygenase inhibitory activities of eucalyptol formulated in the PGSS-micronized particles was sustained. Findings from this study showed that the scCO₂-assisted micronization can be used for encapsulation of volatile drugs in polymeric microparticles without affecting bioactivity of the drug.

Application of supercritical carbon dioxide as an alternative solvent for microformulation of the volatile unstable drug, eucalyptol in polymeric composites.

Nigella sativa oil entrapped polycaprolactone nanoparticles for leishmaniasis treatment

This study is the first to investigate the antileishmanial activities of Nigella sativa oil (NSO) entrapped poly-ɛ-caprolactone (PCL) nanoparticles on Leishmania infantum promastigotes and amastigotes in vitro. NSO molecules with variable initial doses of 50, 100, 150, and 200 mg were successfully encapsulated into PCL nanoparticles identified as formulations NSO1, NSO2, NSO3, and NSO4, respectively. This process was characterised by scanning electron microscope, dynamic light scattering, Fourier transform infrared, encapsulation efficiency measurements, and release profile evaluations. The resulting synthetised nanoparticles had sizes ranging between 200 and 390 nm. PCL nanoparticles encapsulated 98% to 80% of initial doses of NSO and after incubation released approximately 85% of entrapped oil molecules after 288 h. All investigated formulations demonstrated strong antileishmanial effects on L. infantum promastigotes by inhibiting up to 90% of parasites after 192 h. The tested formulations decreased infection indexes of macrophages in a range between 2.4- and 4.1-fold in contrast to control, thus indicating the strong anti-amastigote activities of NSO encapsulated PCL nanoparticles. Furthermore, NSO-loaded PCL nanoparticles showed immunomodulatory effects by increasing produced nitric oxide amounts within macrophages by 2-3.5-fold in contrast to use of free oil. The obtained data showed significant antileishmanial effects of NSO encapsulated PCL nanoparticles on L. infantum promastigotes and amastigotes.

Large-Scale Comparative Analysis of Eugenol-Induced/Repressed Genes Expression in Aspergillus flavus Using RNA-seq

Aflatoxin B₁ (AFB₁), which is mainly produced by Aspergillus flavus and Aspergillus parasiticus, is the most toxic and hepatocarcinogenic polyketide known. Chemical fungicides are currently utilized to reduce this fungal contaminant, but they are potentially harmful to human health and the environment. Therefore, natural anti-aflatoxigenic products are used as sustainable alternatives to control food and feed contamination. For example, eugenol, presents in many essential oils, has been identified as an aflatoxin inhibitor. However, its exact mechanism of inhibition is yet to be clarified. In this study, the anti-aflatoxigenic mechanism of eugenol in A. flavus was determined using a comparative transcriptomic approach. Twenty of twenty-nine genes in the aflatoxin biosynthetic pathway were down-regulated by eugenol. The most strongly down-regulated gene was aflMa, followed by aflI, aflJ, aflCa, aflH, aflNa, aflE, aflG, aflM, aflD, and aflP. However, the expression of the regulator gene aflR did not change significantly and the expression of aflS was slightly up-regulated. The down-regulation of the global regulator gene veA resulted in the up-regulation of srrA, and the down-regulation of ap-1 and mtfA. The early developmental regulator brlA was profoundly up-regulated in A. flavus after eugenol treatment. These results suggested a model in which eugenol improves fungal development by up-regulating the expression of brlA by the suppression of veA expression and inhibits aflatoxin production through the suppression of veA expression. Exposure to eugenol also caused dysregulated transcript levels of the G protein-coupled receptors (GPCRs) and oxylipins genes. A Gene Ontology analysis indicated that the genes that were highly responsive to eugenol were mainly enriched in RNA-binding functions, suggesting that post-transcriptional modification plays a pivotal role in aflatoxin biosynthesis. KEGG analysis showed that ribosome biogenesis was the most dysregulated pathway, suggesting that eugenol dysregulates ribosome biogenesis, which then interrupts the biosynthesis of Nor-1, Ver-1, and OmtA, and prevents aflatoxisomes performing their normal function in aflatoxin production. In conclusion, our results indicated that eugenol inhibited AFB₁ production by modulating the expression of structural genes in aflatoxin pathway, fungal antioxidant status, post-transcriptional modifications and biosynthesis of backbone enzymes in A. flavus.

Functionalization of Lipid-Based Nutrient Supplement with β-Cyclodextrin Inclusions of Oregano Essential Oil

Intestinal parasitic infection is one of the main causes of acute undernutrition in children. Oral consumption of oregano essential oil (OEO) can reduce intestinal parasitic infections, however, its addition to therapeutic and supplementary foods is hampered by its undesirable flavor. The objective of this study was to develop a functional lipid-based nutrient supplement (LNS) containing OEO, which is stable, acceptable and provides targeted intestinal delivery of bioactive. β-cyclodextrin (β-CyD) inclusion complexes of OEO (β-CyD-OEO), and carvacrol (β-CyD-CV) (1:1 molar) were prepared using slurry complexation (-20 °C) method and characterized based on encapsulation efficiency, moisture content, morphology, and 2-phase in vitro digestion stability. Carvacrol (CV) content was measured using reverse phase HPLC-UV. LNS containing β-CyD-OEO (27.2 mg encapsulate/20 g LNS) was formulated using Indian staples and ingredients. Discriminatory sensory tests (triangle) were performed with college students (n = 58) and low-income women (n = 25), with young children at home (1 to 6 years), living in Mehsana, India to evaluate differences between LNS with and without bioactive ingredient (β-CyD-OEO only). Moisture of dried complexes ranged 9.1% to 9.7% d.b., whereas water activity 0.35 to 0.412. The complex size and encapsulation efficiency of β-CyD-OEO and β-CyD-CV were 1.5 to 7 μm and 4 to 20 μm, and 86.04 ± 4.48% and 81.39 ± 3.34%, respectively. The bioactive complexes were stable through the gastric and intestinal phases. Bioaccessibility of encapsulated CV ranged 6.0% to 7.7%. Sensory tests revealed no differences (P > 0.05) in color, aroma, and taste between LNS with and without β-CyD-OEO complexes. Functionalization of LNS with β-CyD-OEO is feasible based on in vitro stability and sensory studies.

PRACTICAL APPLICATION

Despite its antiparasitic activities, the addition of oregano essential oil into foods is limited due to its strong flavor and volatility. In this study, we evaluated the encapsulation of oregano essential oil with β-cyclodextrin and its addition into lipid-based nutrition supplements. The results revealed that complex encapsulation efficiency was above 80%. Also, the bioactive complexes were stable under in vitro gastrointestinal conditions. Sensory evaluation of LNS with and without encapsulated essential oil showed no difference in terms of color, aroma, and taste. The functional LNS can both address nutrient insufficiency as well as parasitic infection among malnourished populations in low-resource settings.

Solid lipid nanoparticles carrying Eugenia caryophyllata essential oil: the novel nanoparticulate systems with broad-spectrum antimicrobial activity

In this study, solid lipid nanoparticles containing Eugenia caryophyllata essential oil (SLN-EO) were prepared by high-shear homogenization and ultrasound methods, and used to eradicate pathogens. SLN formulations were evaluated for their size, zeta potential and encapsulation efficacy (EE). The morphological and thermal properties of the formulations were analysed by transmission electron microscopy (TEM) and differential scanning calorimetry methods. The lead formulations were chosen and tested with minimum inhibitory concentration (MIC), MBC and time-kill methods to investigate the antimicrobial activity against Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. The particle size of three final formulations were 397 ± 10·1, 786·9 ± 11 and 506·4 ± 22 nm respectively. The zeta potential of all formulations was negative values. The size of the formulations was slightly increased during 3 months storage at 25°C. The TEM imaging showed that formulation had spherical shape. The EE of EO was estimated approximately 70%. MIC and MCC values of SLN-EO were lower than those of the oil alone. The time-kill studies showed that SLN-EO was either equivalent to or better than EO (P-value <0·05). The results of this study highlighted the effectiveness of SLN formulations against human pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

Microbial resistance to antibiotics is a major problem in the treatment of diseases. Therefore, overcoming antimicrobial resistance is an urgent need. Drug delivery via nanoparticles and applying natural products are promising approaches to reduce microbial resistance. This study is designed to evaluate the antimicrobial activity of solid lipid nanoparticles (SLN) containing Eugenia caryophyllata essential oil (EO) against human pathogens. The results indicated that the antimicrobial activity of EO was remarkably enhanced when encapsulated in SLN.

Enhanced anticancer activity of drug nanoparticles formulated with β-cyclodextrin

Camptothecin (CPT) is a potent chemotherapeutic agent that shows a broad spectrum of anticancer activities. However, it is clinically inactive because of poor aqueous solubility, rapid aqueous hydrolysis, and unexpected side effects. Three strategies have extensively been adopted to improve its dissolution rate including reduction of drug particle size to a nanoscale, use of an amorphous state, and the formation of inclusion compounds. In our study, we combined these three strategies together by constructing CPT nanoparticles by creating an inclusion complex with β-cyclodextrin (BCD). This new CPT formulation showed a rod-like structure of nanoscaled size and with semiamorphous or amorphous CPT. These BCD-CPT nanoparticles showed improved dissolution rate, stability, dispersion, and cellular uptake. When tested on cancer cells, BCD-CPT nanoparticles showed a much higher anticancer activity (IC50=14-28 μmol/l) in comparison with free CPT (IC50>500 μmol/l) and CPT nanocrystals (IC50>200 μmol/l). In addition, BCD-CPT nanoparticles can be physically mixed with CPT nanocrystals, leading to CPT formulations with tailored drug-release profiles to achieve customized therapeutics and flexible treatments in clinics.

Antimicrobial activity of eugenol and essential oils containing eugenol: A mechanistic viewpoint

Eugenol is a hydroxyphenyl propene, naturally occurring in the essential oils of several plants belonging to the Lamiaceae, Lauraceae, Myrtaceae, and Myristicaceae families. It is one of the major constituents of clove (Syzygium aromaticum (L.) Merr. & L.M. Perry, Myrtaceae) oil and is largely used in both foods and cosmetics as a flavoring agent. A large body of recent scientific evidence supports claims from traditional medicine that eugenol exerts beneficial effects on human health. These effects are mainly associated with antioxidant and anti-inflammatory activities. Eugenol has also shown excellent antimicrobial activity in studies, being active against fungi and a wide range of gram-negative and gram-positive bacteria. The aim of this review is to analyze scientific data from the main published studies describing the antibacterial and antifungal activities of eugenol targeting different kind of microorganisms, such as those responsible for human infectious diseases, diseases of the oral cavity, and food-borne pathogens. This article also reports the effects of eugenol on multi-drug resistant microorganisms. On the basis of this collected data, eugenol represents a very interesting bioactive compound with broad spectrum antimicrobial activity against both planktonic and sessile cells belonging to food-decaying microorganisms and human pathogens.