Essential oils and their components in combating fungal pathogens of animal and human skin

Enhancing Therapeutic Efficacy of Cinnamon Essential Oil by Nanoemulsification for Intravaginal Treatment of Candida Vaginitis

Background

Due to its prevalence, recurrence, and the emergence of drug-resistance, Candida vaginitis significantly impacts the well-being of women. Although cinnamon essential oil (CEO) possesses antifungal activity, its hydrophobic properties limit its clinical application.

Purpose

To overcome this challenge, a nanoemulsification technology was employed to prepare cinnamon essential oil-nanoemulsion (CEO@NE), and its therapeutic efficacy and action mechanism for Candida vaginitis was investigated in vivo and in vitro.

Materials and Methods

CEO@NE, composed of 4% CEO, 78% distilled water, and 18% Tween 80, was prepared by ultrasonic nanoemulsification. The physical properties, anti-Candida activity, cytotoxicity, immunomodulatory potential and storage stability of CEO@NE were explored. Subsequently, the effect of intravaginal CEO@NE treatment on Candida vaginitis was investigated in mice. To comprehend the possible mechanism of CEO@NE, an analysis was conducted to ascertain the production of intracellular reactive oxygen species (ROS) in C. albicans.

Results

CEO@NE, with the droplet size less than 100 nm and robust storage stability for up to 8 weeks, exhibited comparable anti-Candida activity with CEO. CEO@NE at the concentration lower than 400 μg/mL had no cytotoxic and immunomodulatory effects on murine splenocytes. Intravaginal treatment of CEO@NE (400 μg/mL, 20 μL/day/mouse for 5 consecutive days) curbed Candida colonization, ameliorated histopathological changes, and suppressed inflammatory cytokine production in mice intravaginally challenged with C. albicans. Notably, this treatment preserved the density of vaginal lactic acid bacteria (LAB) crucial for vaginal health. Co-culturing C. albicans with CEO@NE revealed concentration-dependent augmentation of intracellular ROS generation and ensuing cell death. In addition, co-culturing LPS-stimulated murine splenocytes with CEO@NE yielded a decrease in the generation of cytokines.

Conclusion

This discovery provides insight into the conceivable antifungal and anti-inflammatory mechanisms of CEO@NE to tackle Candida vaginitis. CEO@NE offers a promising avenue to address the limitations of current treatments, providing novel strategy for treating Candida vaginitis.

Wild thyme (Thymus serpyllum L.): a review of the current evidence of nutritional and preventive health benefits

Thymus serpyllum L. (Lamiaceae), known in English as 'wild thyme', is primarily found in the Palearctic realm (Eurasia, North Africa) and has been utilized traditionally for culinary, nutritional, medicinal, and aromatic purposes. The essential oil extracted from wild thyme is particularly noteworthy, being used extensively in the food industry as a flavoring agent and preservative. The plant's aerial parts are commonly employed as an element of the diet (e.g., tea)/for culinary uses and in local/traditional medicine (primarily for managing respiratory and gastrointestinal conditions), similar to the use of common thyme. There is practically no information available on the species' nutritional benefits. Pharmacological studies, including in vitro and in vivo research, alongside a limited number of clinical trials, have investigated extracts of Thymus serpyllum, although these extracts are often phytochemically poorly characterized in different experimental protocols and models. These studies have demonstrated a range of therapeutic effects, such as antimicrobial (notably the essential oil) and anti-inflammatory, as well as its preventative health benefits and nutritional value of wild thyme. Preclinical studies have corroborated the plant's anti-inflammatory potential, particularly in conditions like inflammatory bowel diseases (IBD) and irritable bowel syndromes (IBS). Additionally, evidence of hepatoprotective activities and benefits in managing metabolic syndrome and cardiovascular health issues, such as lipid metabolism regulation, cholesterol reduction, antidiabetic, antihypertensive, and immunomodulatory effects, have been observed predominantly in rodent models. Phytochemical analysis of wild thyme reveals an essential oil fraction below 1%, along with non-volatile compounds predominantly comprising phenolic acids (such as rosmarinic, salvianolic, and caffeic acids) and flavonoids (mainly glucosides of luteolin, apigenin, and their derivatives). These components are believed to contribute significantly to the plant's medicinal, nutritional, and preventive health properties. Despite promising findings, there is a need for more rigorously designed controlled clinical trials using phytochemically characterized wild thyme. The plant has an excellent safety and tolerability record. This review at the interface of nutritional/preventive health properties and as pharmacological activities highlights the current role of wild thyme in nutrition and general healthcare as well as its future potential, and also points to important gaps in the literature.

Medicinal Plants of the Flora of Kazakhstan Used in the Treatment of Skin Diseases

The skin shows the physiological condition of the body's organs and systems that prevent infections and physical damage. Throughout the ages, in folk medicine, phytotherapy was considered a primary form of treatment in all countries, including Kazakhstan, due to the abundance and availability of plant-based remedies. This paper discusses several medicinal plants that are traditionally used in the treatment of skin diseases in the Republic of Kazakhstan. The chemical composition of these plants was analyzed, with a particular focus on the biologically active basic compounds responsible for their therapeutic efficiency in treating skin ailments.

Essential Oils and Melatonin as Functional Ingredients in Dogs

Simple Summary

Phytogenics are plant-based compounds with beneficial actions in feed technology and/or animal health. These so-called plant secondary metabolites are very diverse and with wide possible applications in humans and animals. Among them, essential oils (EOs) are the most used in feed for livestock and pets. Lately, melatonin has acquired new and interesting applications in dogs. Recent studies using EOs and/or melatonin in dog feeding and their involvement in health aspects are presented.

Abstract

The use of nutraceuticals or functional ingredients is increasingly widespread in human food; their use is also widespread in animal feed. These natural compounds generally come from plant materials and comprise a wide range of substances of a very diverse chemical nature. In animals, these compounds, so-called phytogenics, are used to obtain improvements in feed production/stability and also as functional components with repercussions on animal health. Along with polyphenols, isoprenoid compounds represent a family of substances with wide applications in therapy and pet nutrition. Essential oils (EOs) are a group of complex substances with fat-soluble nature that are widely used. Melatonin is an indolic amine present in all living with amphiphilic nature. In this work, we present a review of the most relevant phytogenics (polyphenol, isoprenoid, and alkaloid compounds), their characteristics, and possible uses as nutraceuticals in dogs, with special emphasis on EOs and their regulatory aspects, applied in foods and topically. Additionally, a presentation of the importance of the use of melatonin in dogs is developed, giving physiological and practical aspects about its use in dog feeding and also in topical application, with examples and future projections. This review points to the combination of EOs and melatonin in food supplements and in the topical application as an innovative product and shows excellent perspectives aimed at addressing dysfunctions in pets, such as the treatment of stress and anxiety, sleep disorders, alopecia, and hair growth problems, among others.

Transcriptomic Responses of Mycoplasma bovis Upon Treatments of trans-Cinnamaldehyde, Carvacrol, and Eugenol

Mycoplasma bovis (M. bovis) is an insidious, wall-less primary bacterial pathogen that causes bovine pneumonia, mid-ear infection, mastitis, and arthritis. The economic losses caused by M. bovis due to culling, diminished milk production, and feed conversion are underestimated because of poor diagnosis/recognition. Treatment with common antibiotics targeting the cell wall is ineffective. Plant-derived antimicrobials (PDAs) such as food-grade trans-cinnamaldehyde (TC), eugenol (EU), and carvacrol (CAR) are inexpensive and generally regarded as safe for humans and animals yet possess strong anti-bacterial properties. In preliminary studies, we found that all three PDAs inhibited the growth of M. bovis in vitro. Through RNA sequencing, we report here that CAR affected the expression of 153 genes which included the downregulation of energy generation-related proteins, pentose phosphate pathway, and upregulation of ribosomes and translation-related proteins. Few differentially expressed genes were found when M. bovis was treated with TC, EU, or when the three PDAs were double or triple combined. Our results suggest that, as opposed to the effect of CAR, the growth-inhibitory effects of TC and EU at levels tested may be exerted through mechanisms other than gene expression regulations.

Meta-analysis of the antifungal activities of three essential oils as alternative therapies in dermatophytosis infections

Aims

This work examines the available scientific evidence about the efficiency of essential oils (EO) as an alternative therapy to traditional treatment of fungal infections, including onychomycosis, assessing the effect of the three EO most frequently studied for their antifungal activity (thyme, cinnamon and tea tree EO) against three causative agents of fungal diseases in humans: Trichophyton rubrum, Trichophyton mentagrophytes complex and Candida albicans.

Methods and Results

The PRISMA statement protocol was followed to conduct a bibliographical search and 54 articles that met all the inclusion criteria were retrieved. Differences were observed in the MIC and MFC values depending on the micro‐organism strain and the EO used. The lowest MIC were observed with Cinnamomum zeylanicum EO (0.013–1120 μl ml⁻¹) against the three micro‐organisms. For MFC, the lowest value was found for Thymus vulgaris EO (4.2 μl ml⁻¹) against Trichophyton rubrum.

Conclusions

The antifungal effects of EO could be a very promising solution to overcome the therapeutic shortcomings of antimycotic medication. More experiments are needed to examine the properties of these oils to devise effective and nonaggressive therapies for treatment of dermatophytosis.

Significance and Impact of Study

The results indicate that EO remain good candidates for future treatments and could provide a solution for failed medications and/or adverse reactions to current pharmacological treatments.

Antifungal and synergistic activities of some selected essential oils on the growth of significant indoor fungi of the genus Aspergillus

The study aimed to assess the antifungal activity of twenty-five essential oils (EOs) and the potential synergistic activity of the most effective EOs against significant indoor fungi of the genus Aspergillus [A. fumigatus (KBio-122), A. flavus (KBio-134), A. terreus (KBio-145) and A. niger (KBio-202)]. The chemical composition of all EOs was evaluated by the gas chromatography coupled with mass spectrometry (GC/MS) and gas chromatography with flame ionization detector (GC-FID) analysis. The antifungal susceptibility of EOs was evaluated by using the broth microdilution method. The most effective EOs were selected to determine the minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) at a concentration range from 256 to 0.125 μg/mL. For the synergistic activities, the most effective EOs were tested using the chessboard pattern. The most sensitive strain to treatments with essential oils alone and in the combination of EOs was A. flavus (KBio-134). The chessboard assay showed that combinations of lemongrass and thyme EOs proved the most potent synergistic antifungal activity (FICI = 0.1875) against A. fumigatus (KBio-122). The synergy displayed by a combination of some EOs may be used to control fungal growth or increasing resistance to available synthetic antifungals, consequently permitting the reduction of their most active doses.

Synthesis and Nano-Sized Characterization of Bioactive Oregano Essential Oil Molecule-Loaded Small Unilamellar Nanoliposomes with Antifungal Potentialities

The development of greener nano-constructs with noteworthy biological activity is of supreme interest, as a robust choice to minimize the extensive use of synthetic drugs. Essential oils (EOs) and their constituents offer medicinal potentialities because of their extensive biological activity, including the inhibition of fungi species. However, their application as natural antifungal agents are limited due to their volatility, low stability, and restricted administration routes. Nanotechnology is receiving particular attention to overcome the drawbacks of EOs such as volatility, degradation, and high sensitivity to environmental/external factors. For the aforementioned reasons, nanoencapsulation of bioactive compounds, for instance, EOs, facilitates protection and controlled-release attributes. Nanoliposomes are bilayer vesicles, at nanoscale, composed of phospholipids, and can encapsulate hydrophilic and hydrophobic compounds. Considering the above critiques, herein, we report the in-house fabrication and nano-size characterization of bioactive oregano essential oil (Origanum vulgare L.) (OEO) molecules loaded with small unilamellar vesicles (SUV) nanoliposomes. The study was focused on three main points: (1) multi-compositional fabrication nanoliposomes using a thin film hydration-sonication method; (2) nano-size characterization using various analytical and imaging techniques; and (3) antifungal efficacy of as-developed OEO nanoliposomes against Trichophyton rubrum (T. rubrum) by performing the mycelial growth inhibition test (MGI). The mean size of the nanoliposomes was around 77.46 ± 0.66 nm and 110.4 ± 0.98 nm, polydispersity index (PdI) of 0.413 ± 0.015, zeta potential values up to -36.94 ± 0.36 mV were obtained by dynamic light scattering (DLS). and spherical morphology was confirmed by scanning electron microscopy (SEM). The presence of OEO into nanoliposomes was displayed by attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. Entrapment efficiency values of 79.55 ± 6.9% were achieved for OEO nanoliposomes. In vitro antifungal activity of nanoliposomes tested against T. rubrum strains revealed that OEO nanoliposomes exhibited the highest MGI, 81.66 ± 0.86%, at a concentration of 1.5 µL/mL compared to the rest of the formulations. In summary, this work showed that bioactive OEO molecules with loaded nanoliposomes could be used as natural antifungal agents for therapeutical purposes against T. rubrum.