Antimicrobial Effect of Thymus capitatus and Citrus limon var. pompia as Raw Extracts and Nanovesicles

Current status, technology, regulation and future perspectives of essential oils usage in the food and drink industry

Nowadays, essential oils (EOs) have a wide use in many applications such as in food, cosmetics, pharmaceutical and animal feed products. Consumers' preferences concerning healthier and safer foodstuffs lead to an increased demand for natural products, in replacement of synthetic substances, used as preservatives, flavourings etc. EOs, besides being safe, are promising alternatives as natural food additives, and much research has been carried out on their antioxidant and antimicrobial activity. The initial purpose of this review is to discuss conventional and 'green' extraction techniques along with their basic mechanism for the isolation of EOs from aromatic plants. This review aims to provide a broad overview of the current knowledge about the chemical constitution of EOs while considering the existence of different chemotypes, since bioactivity is attributed to the chemical composition - qualitative and quantitative - of EOs. Although the food industry primarily uses EOs as flavourings, an overview on recent applications of EOs in food systems and active packaging is provided. EOs exhibit poor solubility in water, oxidation susceptibility, negative organoleptic effect and volatility, restricting their use. Encapsulation techniques have been proven to be one of the best approaches to preserve the biological activities of EOs and minimize their effects on food sensory qualities. Herein, different encapsulation techniques and their basic mechanism for loading EOs are discussed. EOs are highly accepted by consumers, who are often under the misconception that 'natural' means safe. This is, however, an oversimplification, and the possible toxicity of EOs should be taken into consideration. Thus, in the final section of the current review, the focus is on current EU legislation, safety assessment and sensory evaluation of EOs. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Oral Treatment with Plant-Derived Exosomes Restores Redox Balance in H2O2-Treated Mice

Plant-derived exosomes (PDEs) are receiving much attention as a natural source of antioxidants. Previous research has shown that PDEs contain a series of bioactives and that their content varies depending on the fruit or vegetable source. It has also been shown that fruits and vegetables derived from organic agriculture produce more exosomes, are safer, free of toxic substances, and contain more bioactives. The aim of this study was to investigate the ability of orally administered mixes of PDE (Exocomplex^®) to restore the physiological conditions of mice treated for two weeks with hydrogen peroxide (H₂O₂), compared with mice left untreated after the period of H₂O₂ administration and mice that received only water during the experimental period. The results showed that Exocomplex^® had a high antioxidant capacity and contained a series of bioactives, including Catalase, Glutathione (GSH), Superoxide Dismutase (SOD), Ascorbic Acid, Melatonin, Phenolic compounds, and ATP. The oral administration of Exocomplex^® to the H₂O₂-treated mice re-established redox balance with reduced serum levels of both reactive oxygen species (ROS) and malondialdehyde (MDA), but also a general recovery of the homeostatic condition at the organ level, supporting the future use of PDE for health care.

Antimicrobial Efficiency of Pistacia lentiscus L. Derivates against Oral Biofilm-Associated Diseases-A Narrative Review

Pistacia lentiscus L. (PlL) has been used for centuries in traditional medicine. The richness in antimicrobial biomolecules of Pll derivates can represent an alternative to chemically formulated agents used against oral infections. This review summarizes the knowledge on the antimicrobial activity of PlL essential oil (EO), extracts, and mastic resin against microorganisms being of relevance in oral biofilm-associated diseases. Results demonstrated that the potential of PlL polyphenol extracts has led to increasing scientific interest. In fact, the extracts are a significantly more effective agent than the other PlL derivates. The positive findings regarding the inhibition of periodontal pathogens and C. albicans, together with the antioxidant activity and the reduction of the inflammatory responses, suggest the use of the extracts in the prevention and/or reversal of intraoral dysbiosis. Toothpaste, mouthwashes, and local delivery devices could be effective in the clinical management of these oral diseases.

Xerostomia: From Pharmacological Treatments to Traditional Medicine-An Overview on the Possible Clinical Management and Prevention Using Systemic Approaches

Despite high incidence rates and severe complications, the management of xerostomia lacks clinical guidelines. The aim of this overview was to summarize the clinical experience derived from the last 10 years of treatments and prevention using systemic compounds. Results showed that the cytoprotective drug amifostine, and its antioxidant agents, are the most discussed as preventive agents of xerostomia in head and neck cancer (HNC) patients. In the presence of the disease, the pharmacological treatments have been mainly directed to stimulate secretion of the damaged salivary glands, or to counteract a decreased capacity of the antioxidant system, in view of an increasing of reactive oxygen species (ROS). However, the data demonstrated low ability of the drugs, together with a great number of side effects, which strongly limit their use. Concerning traditional medicine (TM), valid clinical trials are so limited that neither the efficacy nor the absence of interferences to concomitant chemical therapies can be validated. Consequently, the management of xerostomia and its devastating complications remain a very significant void in daily clinical practice.

Six Spain Thymus essential oils composition analysis and their in vitro and in silico study against Streptococcus mutans

BACKGROUND

Streptococcus mutans is a well-known oral pathogen that plays a critical role in the development of dental caries. Many studies have been directed to discover the chemical compounds present in natural products to inhibit the growth and biofilm formation activity of S. mutans. Thymus essential oils exhibit good inhibition on the growth and pathogenesis of S. mutans. However, details about the active compounds in Thymus essential oil and the inhibition mechanism still remain unclear. The aim of this study was to investigate the antimicrobial activity of 6 Thymus species (Three samples of Thymus vulgaris, two samples of Thymus zygis, and one sample of Thymus satureioides essential oils) on S. mutans, to identify the potential active components, and to reveal the underlying mechanism.

METHODS

The composition of Thymus essential oils was analyzed by gas chromatography-mass spectrometry. And its antibacterial effect was evaluated based on the bacterial growth, acid production, biofilm formation and genetic expression of virulence factors by S. mutans. Potential active components of the Thymus essential oil were identified using molecular docking and correlation analysis.

RESULTS

GC-MS analysis showed that the major components in the 6 Spain Thymus essential oils were linalool, α-terpineol, p-cymene, thymol and carvacrol. MIC and MBC analysis showed that 3 Thymus essential oils showed very sensitive antimicrobial activity, and were chosen for further analysis. The 3 Thymus essential oil exhibited a significant inhibitory effect on acid production, adherence and biofilm formation of S. mutans and the expression of virulence genes, such as brpA, gbpB, gtfB, gtfC, gtfD, vicR, spaP and relA. Correlation analysis showed that phenolic components, such as carvacrol and thymol, were positively related to DIZ value, which suggests that they are the potential antimicrobial components. Molecular docking between the Thymus essential oil components and virulence proteins also found that carvacrol and thymol exhibited strong binding affinity with functional domains of virulence genes.

CONCLUSIONS

Thymus essential oil showed significant inhibition against the growth and pathogenesis of S. mutans depending on their composition and concentration. And phenolic compounds, such as carvacrol and thymol, are the major active components. Thymus essential oil could be used in oral healthcare products as a potential anti-caries ingredient.

Effect of potassium salts on the structure of γ-cyclodextrin MOF and the encapsulation properties with thymol

BACKGROUND

Thymol is a natural essential oil with strong volatility, low solubility, poor dispersion, strong irritation, and an unpleasant smell, which often requires appropriate porous materials to encapsulate thymol during the application process. However, the encapsulation efficiency of thymol in inclusion complexes is low, and new methods of encapsulation need to be developed. In the present study, the encapsulation capacity, storage stability, and antibacterial activity of thymol were investigated using γ-cyclodextrin (γ-CD) metal-organic frameworks (MOFs) by cocrystallization and high-temperature adsorption methods. The effect of different potassium salts (i.e. KOH, KCl, and KAc) on the structure and complexation of γ-CD-MOFs was also analyzed.

RESULTS

Compared with γ-CD, the thymol encapsulation capacity of γ-CD-MOFs was increased by two- to three-fold, with the encapsulation content following the order: KAc-γ-CD-MOF (293.8 mg g^-1 ) > KOH-γ-CD-MOF (287.7 mg g^-1 ) > KCl-γ-CD-MOF (249.3 mg g^-1 ). The anions in the solution participate in the coordination and influence the symmetry relationship between atoms and ions. This explains the differences in both the three-dimensional γ-CD-MOF structure and the thymol encapsulation amount, as well as the high storage stability of thymol.

CONCLUSION

The in vitro release kinetics and antibacterial experiments showed that the inclusion complexes prepared by γ-CD-MOFs had higher stability, sustainability, and antibacterial activity, which suggests that it is an excellent complex material for industrial and agricultural applications. © 2022 Society of Chemical Industry.

Nano-enabled plant-based colloidal delivery systems for bioactive agents in foods: Design, formulation, and application

Consumers are becoming increasingly aware of the impact of their dietary choices on the environment, animal welfare, and health, which is causing many of them to adopt more plant-based diets. For this reason, many sectors of the food industry are reformulating their products to contain more plant-based ingredients. This article describes recent research on the formation and application of nano-enabled colloidal delivery systems formulated from plant-based ingredients, such as polysaccharides, proteins, lipids, and phospholipids. These delivery systems include nanoemulsions, solid lipid nanoparticles, nanoliposomes, nanophytosomes, and biopolymer nanoparticles. The composition, size, structure, and charge of the particles in these delivery systems can be manipulated to create novel or improved functionalities, such as improved robustness, higher optical clarity, controlled release, and increased bioavailability. There have been major advances in the design, assembly, and application of plant-based edible nanoparticles within the food industry over the past decade or so. As a result, there are now a wide range of different options available for creating delivery systems for specific applications. In the future, it will be important to establish whether these formulations can be produced using economically viable methods and provide the desired functionality in real-life applications.

The Oral Microbiota: Community Composition, Influencing Factors, Pathogenesis, and Interventions

The human oral cavity provides a habitat for oral microbial communities. The complexity of its anatomical structure, its connectivity to the outside, and its moist environment contribute to the complexity and ecological site specificity of the microbiome colonized therein. Complex endogenous and exogenous factors affect the occurrence and development of the oral microbiota, and maintain it in a dynamic balance. The dysbiotic state, in which the microbial composition is altered and the microecological balance between host and microorganisms is disturbed, can lead to oral and even systemic diseases. In this review, we discuss the current research on the composition of the oral microbiota, the factors influencing it, and its relationships with common oral diseases. We focus on the specificity of the microbiota at different niches in the oral cavity, the communities of the oral microbiome, the mycobiome, and the virome within oral biofilms, and interventions targeting oral pathogens associated with disease. With these data, we aim to extend our understanding of oral microorganisms and provide new ideas for the clinical management of infectious oral diseases.

The Potentiality of Plant-Derived Nanovesicles in Human Health-A Comparison with Human Exosomes and Artificial Nanoparticles

Research in science and medicine is witnessing a massive increases in literature concerning extracellular vesicles (EVs). From a morphological point of view, EVs include extracellular vesicles of a micro and nano sizes. However, this simplistic classification does not consider both the source of EVs, including the cells and the species from which Evs are obtained, and the microenvironmental condition during EV production. These two factors are of crucial importance for the potential use of Evs as therapeutic agents. In fact, the choice of the most suitable Evs for drug delivery remains an open debate, inasmuch as the use of Evs of human origin may have at least two major problems: (i) autologous Evs from a patient may deliver dangerous molecules; and (ii) the production of EVs is also limited to cell factory conditions for large-scale industrial use. Recent literature, while limited to only a few papers, when compared to the papers on the use of human EVs, suggests that plant-derived nanovesicles (PDNV) may represent a valuable tool for extensive use in health care.

Optimizing glycerosome formulations via an orthogonal experimental design to enhance transdermal triptolide delivery

Triptolide exerts strong anti-inflammatory and immunomodulatory effects; however, its oral administration might be associated with side effects. Transdermal administration can improve the safety of triptolide. In this study, glycerosomes were prepared as the transdermal vehicle to enhance the transdermal delivery of triptolide. With entrapment efficiency and drug loading as dependent variables, the glycerosome formulation was optimized using an orthogonal experimental design. Phospholipid-to-cholesterol and phospholipid-to-triptolide mass ratios of 30:1 and 5:1, respectively and a glycerol concentration of 20 % (V/V) were used in the optimization. The glycerosomes prepared with the optimized formulation showed good stability, with an average particle size of 153.10 ± 2.69 nm, a zeta potential of -45.73 ± 0.60 mV and an entrapment greater than 75 %. Glycerosomes significantly increased the transdermal delivery of triptolide compared to conventional liposomes. As efficient carriers for the transdermal delivery of drugs, glycerosomes can potentially be used as an alternative to oral triptolide administration.

Essential oils as anticancer agents: Potential role in malignancies, drug delivery mechanisms, and immune system enhancement

Cancer retains a central place in fatality rates among the wide variety of diseases known world over, and the conventional synthetic medicaments, albeit used until now, produce numerous side effects. As a result, newer, better, and safer alternatives such as natural plant products, are gravely required. Essential oils (EOs) offer a plethora of bioactivities including antibacterial, antiviral, antioxidant, and anticancer properties, therefore, the use of EOs in combination with synthetic drugs or aromatherapy continues to be popular in many settings. In view of the paramount importance of EOs and their potential bioactivities, this review summarizes the current knowledge on the interconnection between EOs and cancer treatment. In particular, the current review presents an updated summary of the chemical composition of EOs, their current applications in cancer treatments based on clinical studies, and the mechanism of action against the cancer cell lines. Similarly, an overview of using EOs in aromatherapy and enhancing immunity during cancer treatment is provided. Further, this review focuses on the recent technological advancements such as the loading of EOs using protein microspheres, ligands, or nanoemulsions/nanoencapsulation, which offer multiple benefits in cancer treatment via site-specific and target-oriented delivery of drugs. The continuing clinical studies of EOs implicate that their pharmacological applications are a rewarding research area.

Innovative Delivery Systems Loaded with Plant Bioactive Ingredients: Formulation Approaches and Applications

Plants constitute a rich source of diverse classes of valuable phytochemicals (e.g., phenolic acids, flavonoids, carotenoids, alkaloids) with proven biological activity (e.g., antioxidant, anti-inflammatory, antimicrobial, etc.). However, factors such as low stability, poor solubility and bioavailability limit their food, cosmetics and pharmaceutical applications. In this regard, a wide range of delivery systems have been developed to increase the stability of plant-derived bioactive compounds upon processing, storage or under gastrointestinal digestion conditions, to enhance their solubility, to mask undesirable flavors as well as to efficiently deliver them to the target tissues where they can exert their biological activity and promote human health. In the present review, the latest advances regarding the design of innovative delivery systems for pure plant bioactive compounds, extracts or essential oils, in order to overcome the above-mentioned challenges, are presented. Moreover, a broad spectrum of applications along with future trends are critically discussed.

Thymol and Thyme Essential Oil-New Insights into Selected Therapeutic Applications

Thymol (2-isopropyl-5-methylphenol) belongs to the phenolic monoterpenes and mostly occurs in thyme species. It is one of the main compounds of thyme essential oil. Both thymol and thyme essential oil have long been used in traditional medicine as expectorant, anti-inflammatory, antiviral, antibacterial, and antiseptic agents, mainly in the treatment of the upper respiratory system. The current search for new directions of biological or therapeutic activities of natural plant substances with known structures includes thyme essential oil and thymol. Novel studies have demonstrated their antibiofilm, antifungal, antileishmanial, antiviral, and anticancer properties. Also, their new therapeutic formulations, such as nanocapsules containing these constituents, can be beneficial in medicinal practice and create opportunities for their extensive use. Extensive application of thymol and thyme essential oil in the healthcare sector is very promising but requires further research and analysis.

Polyoliposomes: novel polyol-modified lipidic nanovesicles for dermal and transdermal delivery of drugs

Various lipid nanovesicular systems have been developed with the aim to enhance the delivery of drugs via transdermal route. However, their clinical applications are often limited due to the barrier nature of skin and lack of flexibility. Herein, we have modified the conventional nanoliposomes (CLs) prepared by a thin-film hydration method by the addition of a polyol (glycerol) to form novel lipid nanovesicular structures termed 'POLYOLIPOSOMES' (PLs). They were further named as PL-B (before film formation) and PL-A (after film formation), depending on the stage of glycerol addition during production. Optimized CLs, PL-B and PL-A showed spherical nanovesicles and hydrodynamic diameter of 181.3 ± 4.11 nm, 114.2 ± 7.21 nm and 170.2 ± 6.51 nm, respectively. PLs showed significantly higher % entrapment efficiency and deformability index in comparison to CLs, indicating their higher flexibility. Furthermore, DSC and attenuated total relection (ATR)-Fourier transform infrared (FTIR) studies revealed the intercalation of glycerol into the lipid bilayer of PLs and interaction between nanovesicles and skin. Moreover, ex vivo and in vivo skin permeation studies confirmed the enhanced drug delivery of PLs via the transdermal route. Taken together, these results illustrate the potential of PLs as a novel lipid nanovesicular system for drug delivery via the transdermal route for both systematic (PL-B) as well as cutaneous diseases (PL-A).

Entrapment of Citrus limon var. pompia Essential Oil or Pure Citral in Liposomes Tailored as Mouthwash for the Treatment of Oral Cavity Diseases

This work aimed at developing a mouthwash based on liposomes loading Citrus limon var. pompia essential oil or citral to treat oropharyngeal diseases. Vesicles were prepared by dispersing phosphatidylcholine and pompia essential oil or citral at increasing amounts (12, 25 and 50 mg/mL) in water. Transparent vesicle dispersions were obtained by direct sonication avoiding the use of organic solvents. Cryogenic transmission electron microscopy (cryo-TEM) confirmed the formation of unilamellar, spherical and regularly shaped vesicles. Essential oil and citral loaded liposomes were small in size (~110 and ~100 nm, respectively) and negatively charged. Liposomes, especially those loading citral, were highly stable as their physico-chemical properties did not change during storage. The formulations were highly biocompatible against keratinocytes, were able to counteract the damages induced in cells by using hydrogen peroxide, and able to increase the rate of skin repair. In addition, liposomes loading citral at higher concentrations inhibited the proliferation of cariogenic bacterium.

Polyphenols in Dental Applications

(1) Background: polyphenols are a broad class of molecules extracted from plants and have a large repertoire of biological activities. Biomimetic inspiration from the effects of tea or red wine on the surface of cups or glass lead to the emergence of versatile surface chemistry with polyphenols. Owing to their hydrogen bonding abilities, coordination chemistry with metallic cations and redox properties, polyphenols are able to interact, covalently or not, with a large repertoire of chemical moieties, and can hence be used to modify the surface chemistry of almost all classes of materials. (2) Methods: the use of polyphenols to modify the surface properties of dental materials, mostly enamel and dentin, to afford them with better adhesion to resins and improved biological properties, such as antimicrobial activity, started more than 20 years ago, but no general overview has been written to our knowledge. (3) Results: the present review is aimed to show that molecules from all the major classes of polyphenolics allow for low coast improvements of dental materials and engineering of dental tissues.

The Pharmaceutical Ability of Pistacia lentiscus L. Leaves Essential Oil Against Periodontal Bacteria and Candida sp. and Its Anti-Inflammatory Potential

BACKGROUND

Given the increasing request for natural pharmacological molecules, this study assessed the antimicrobial capacity of Pistacia lentiscus L. essential oil (PLL-EO) obtained from the leaves of wild plants growing in North Sardinia (Italy) toward a wide range of periodontal bacteria and Candida, including laboratory and clinical isolates sp., together with its anti-inflammatory activity and safety.

METHODS

PLL-EO was screened by gas chromatography/mass spectrometry. The minimal inhibitory concentration (MIC) was determined. The anti-inflammatory activity was measured by cyclooxygenase (COX-1/2) and lipoxygenase (LOX) inhibition, while the antioxidant capacity was determined electro-chemically and by the MTT assay. The WST-1 assay was used to ascertain cytotoxicity toward four lines of oral cells.

RESULTS

According to the concentrations of terpens, PLL-EO is a pharmacologically-active phytocomplex. MICs against periodontal bacteria ranged between 3.13 and 12.5 µg/ml, while against Candida sp. they were between 6.25 and 12.5 µg/mL. Oxidation by COX-1/2 and LOX was inhibited by 80% and 20% µg/mL of the oil, respectively. Antioxidant activity seemed negligible, and no cytotoxicity arose.

CONCLUSIONS

PLL-EO exhibits a broad-spectrum activity against periodontal bacteria and Candida, with an interesting dual inhibitory capacity toward COX-2 and LOX inflammatory enzymes, and without side effects against oral cells.

DoE directed optimization, development and evaluation of resveratrol loaded ultradeformable vesicular cream for topical antioxidant benefits

Objective: Aim of the present work was to optimize and formulate resveratrol loaded vesicular cream intended for dermal delivery of resveratrol with high skin deposition potential.Methods: Formulation was developed and optimized using Central Composite Design. Amount of phospholipid and sodium cholate were selected as critical material attributes and vesicle size and entrapment efficiency of resveratrol were taken as critical quality attributes. To increase the skin applicability and patient compliance, vesicles were further developed as vesicular cream which was then thoroughly characterized for physicochemical parameters, ex vivo skin permeation/deposition profile and antioxidant potential.Results: Vesicle size and entrapment efficiency of the optimized batch were found to be 178.9 ± 12.87 nm with 72.32 ± 3.45% respectively. Physicochemical properties and viscosity of cream formulation were also found to be favorable for skin applicability. Permeation flux at the end of 24 h was found to be 2.70 ± 0.73, 4.45 ± 0.56 and 4.95 ± 0.69 µg cm^-2 h^-1 for conventional cream, vesicular dispersion, and vesicular cream formulation respectively. Higher drug deposition in the skin via vesicular cream formulation was observed i.e. 335.2 ± 4.12 µg cm^-2 (70.16 ± 0.87%) as compared to conventional cream i.e. 67.12 ± 19.63 µg cm^-2 (14.05 ± 4.11%). Resveratrol encapsulated in vesicular cream has retained its inherent antioxidant activity suggesting the stability of resveratrol in vesicular cream.Conclusion: Thus, it can be concluded that deformable vesicular cream is capable of delivering encapsulated bioactive in deeper layers of skin, where it can be retained for achieving higher dermatological benefits.