Essential Oils against Sarcoptes scabiei.

Herbal remedia are widely employed in folk medicine, and have been more and more often studied and considered in the treatment of several infections. Sarcoptic mange (scabies, when referring to human patients) is a highly contagious skin disease caused by Sarcoptes scabiei (sarcoptiformes, Sarcoptinae), an astigmatid mite which burrows into the epidermis, actively penetrating the stratum corneum. This parasitosis negatively affects livestock productions and represents a constraint on animal and human health. The treatment relies on permethrine and ivermectine but, since these molecules do not have ovicidal action, more than a single dose should be administered. Toxicity, the possible onset of parasite resistance, the presence of residues in meat and other animal products and environmental contamination are the major constraints. These shortcomings could be reduced by the use of plant extracts that have been in vitro or in vivo checked against these mites, sometimes with promising results. The aim of the present study was to review the literature dealing with the treatment of both scabies and sarcoptic mange by plant-derived agents, notably essential oils.

In vitro antimicrobial activity of selected essential oils against bacteria and yeasts isolated from the genital tract of mares.

The aim of the present study, the first to test clinical equine isolates, was to evaluate the antimicrobial activity of commercial essential oils (EOs) obtained from Origanum vulgare, Thymus vulgaris, Cinnamomum zeylanicum, Cymbopogon citratus, Aloysia triphylla and Syzygium aromaticum against Streptococcus spp., Staphylococcus spp., Candida albicans and Rhodotorula spp. previously isolated from uteri of mares with reproductive disorders. T. vulgaris showed the best antibacterial activity against all the selected agents, with MICs ranging from 0.07 mg/mL for S. equi subsp. zooepidemicus to 0.29 mg/mL versus Streptococcus sp. and Staphylococcus spp. isolates and versus C. albicans and Rhodotorula spp., with MICs of 0.46 mg/mL and 1.86 mg/mL, respectively. O. vulgare, S. aromaticum, C. zeylanicum EOs showed good antibacterial activity with MICs ranging from 0.07 mg/mL to 0.29 mg/mL, 0.16 mg/mL to 0.32 mg/mL, 0.07 mg/mL to 0.63 mg/mL, respectively; A. triphylla was the most active EO against Rhodotorula spp. (0.43 mg/mL).

Use of Essential Oils in Veterinary Medicine to Combat Bacterial and Fungal Infections.

Essential oils (EOs) are secondary metabolites of plants employed in folk medicine for a long time thanks to their multiple properties. In the last years, their use has been introduced in veterinary medicine, too. The study of the antibacterial properties of EOs is of increasing interest, because therapies with alternative drugs are welcome to combat infections caused by antibiotic-resistant strains. Other issues could be resolved by EOs employment, such as the presence of antibiotic residues in food of animal origin and in environment. Although the in vitro antimicrobial activity of EOs has been frequently demonstrated in studies carried out on bacterial and fungal strains of different origins, there is a lack of information about their effectiveness in treating infections in animals. The scientific literature reports some studies about in vitro EOs' activity against animal clinical bacterial and fungal isolates, but in vivo studies are very scanty. The use of EOs in therapy of companion and farm animals should follow careful studies on the toxicity of these natural products in relation to animal species and route of administration. Moreover, considering the different behavior of EOs in relation to both species and strain pathogen, before starting a therapy, an aromatogram should be executed to choose the oil with the best antimicrobial activity.

Volatilome Analyses and In Vitro Antimicrobial Activity of the Essential Oils from Five South African Helichrysum Species.

Helichrysum genus was used in folk South African medicine to treat various human disorders. As a part of our on-going research addressing the exploitation of South African plants belonging to this genus, five species were investigated for their volatile and antimicrobial activities. The volatile organic compounds (VOCs) and the essential oils (EOs) were analysed by gas chromatography mass spectrometry (GC-MS). Microdilution was the method used for assessing both antimycotic and antibacterial activities, which was also tested by Kirby-Bauer agar disc diffusion. Total monoterpenes (TMs) dominated the VOCs of four species (H. trilineatum (70.6%), H. edwardsii (79.3%), H. cooperi (84.5%), and H. pandurifolium (57.0%)). H. cooperi and H. edwardsii EOs showed the predominance of TMs (68.2% and 84.5%, respectively), while H. pandurifolium and H. trilineatum EOs were characterized by the prevalence of TSs (86.5% and 43.6%, respectively). H. odoratissimum EO evidenced a similar amount of both TMs (49.5%) and TSs (46.4%). Microsporum canis was more sensitive to these EOs. The lowest minimum inhibitory concentration (MIC) was observed with H. pandurifolium and H. edwardsii EOs (0.25%). H. pandurifolium and H. trilineatum had a good effect on Staphylococcus aureus (MIC 5%). These findings open new perspectives for the exploitation of these natural compounds for application in cosmetics and pharmaceutics.

Helichrysum araxinum Takht. ex Kirp. grown in Italy: volatiloma composition and in vitro antimicrobial activity.

In the present work the composition of biogenic volatile organic compounds (BVOCs) and the essential oil (EO) of Helichrysum araxinum Takht. ex Kirp. aerial parts, together with the antimicrobial activity, were investigated. The results showed the prevalence of sesquiterpene hydrocarbons in both spontaneous emissions as well as in the EO. The main compounds of BVOCs were γ-curcumene (10.7%), γ-muurolene (9.2%), and ß-selinene (8.5%). This latter constituent also showed a similar amount in the EO and represented the most abundant compounds together with α-selinene (8.0%). It is Interesting to note the same percentage of monoterpene hydrocarbons (MHs) in both the aroma profile and the EO (18.0%) with the same most abundant compounds: ß-pinene (6.3% in BVOCs vs. 5.1% in EO, respectively) and limonene (4.5% in VOCs vs. 4.9% in EO, respectively). With regard to the antimycotic activity, the EO showed to be inactive against the tested strains, while a moderate antibacterial activity was shown against Staphylococcus isolates.

Biological Activity of Essential Oils.

Essential oils (EOs) have for a long time been recognized to possess several different biological activities. Several among these secondary plant metabolites exhibit marked antimicrobial effects that have made their use as an antiseptic and/or preservative in food well known, since the ancient times [...].

In Vitro Activity of Essential Oils against Saprolegnia parasitica.

Saprolegnia spp. water molds severely impact fish health in aquaculture, fish farms and hobby fish tanks colonizing mature and immature stages of fishes, as well as eggs. Considering that there are no drugs licensed for treating and/or control the organism, efficient and environmental low-impact methods to control these oomycetes in aquaculture are needed. The aim of the present report was to evaluate the in vitro sensitivity of Saprolegnia parasitica to essential oils (EOs) from Citrus aurantium L., Citrus bergamia Risso et Poiteau, Citrus limon Burm. f., Citrus paradisi Macfad, Citrussinensis Osbeck, Cinnamomum zeylanicum Blume, Cymbopogon flexuosum (Nees ex Steud.) Watson, Foeniculum vulgare Mill., Illicium verum Hook.f., Litsea cubeba (Lour.) Pers., Origanum majorana L., Origanum vulgare L., Pelargonium graveolens L'Hér., Syzygium aromaticum Merr. & L.M.Perry, and Thymus vulgaris L., by microdilution test. The most effective EOs assayed were T. vulgaris and O. vulgare, followed by C. flexuosum, L. cubeba and C. bergamia. These EOs could be of interest for controlling Saprolegnia infections. Nevertheless, further safety studies are necessary to evaluate if these products could be dispersed in tank waters, or if their use should be limited to aquaculture supplies.

Essential Oil Composition and Biological Activity of "Pompia", a Sardinian Citrus Ecotype.

Pompia is a Sardinian citrus ecotype whose botanical classification is still being debated. In the present study, the composition of Pompia peel essential oil (EO) is reported for the first time, along with that of the leaf EO, as a phytochemical contribution to the classification of this ecotype. The peel EO was tested for its antioxidant ability (with both the 2,2-diphenyl-1-picarylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). Moreover, its antimicrobial activities were tested for the first time on dermatophytes (Microsporum canis, Microsporum gypseum, and Trichophyton mentagrophytes), on potentially toxigenic fungi (Fusarium solani, Aspergillus flavus, and Aspergillus niger) as well on bacteria (Escherichia coli, Staphylococcus aureus, and Staphylococcus pseudointermedius). The dominant abundance of limonene in the peel EO seems to distinguish Pompia from the Citrus spp. to which it had previously been associated. It lacks γ-terpinene, relevant in Citrus medica EO. Its relative content of α- and ß-pinene is lower than 0.5%, in contrast to Citrus limon peel EO. Pompia peel and leaf EOs did not show significant amounts of linalool and linalyl acetate, which are typically found in Citrus aurantium. Pompia peel EO antioxidant activity was weak, possibly because of its lack of γ-terpinene. Moreover, it did not exert any antimicrobial effects either towards the tested bacteria strains, or to dermatophytes and environmental fungi.

Antimicrobial Activity of Five Essential Oils against Bacteria and Fungi Responsible for Urinary Tract Infections.

Urinary tract infections are frequently encountered in small animal practice. Escherichia coli and Enterococcus spp. are the most common agents associated to these infections, even though other bacteria and yeasts, such as Candida albicans and Candida famata, may be involved. In view of the increasing problem of the multi-drug resistance, the aim of this study was to investigate the antimicrobial activity of essential oils obtained from star anise (Illicium verum Hook.f.), basil (Ocimum basilicum L.), origanum (Origanum vulgare L.), clary sage (Salvia sclarea L.) and thymus (Thymus vulgaris L.) against multidrug-resistant strains of Escherichia coli, Enterococcus spp., Candida albicans and Candida famata previously isolated from dogs and cats with urinary tract infections. Enterococci were resistant to Illicium verum and Salvia sclarea, such as Candida to Salvia sclarea. Thymus vulgaris and Origanum vulgare essential oils showed the best activity against all the tested pathogens, so they could be proposed for the formulation of external and/or intravesical washes in small animals.

Activity of selected essential oils on spoiling fungi cultured from Marzolino cheese.

Microscopic fungi can be present on a variety of foodstuff, including cheese. They can be responsible for fungal spoilage, causing sensory changes making food unacceptable for human consumption, and posing severe health concerns. Furthermore, some of these organisms are able to resist antimicrobial preservatives provided for by law. Antifungal activity of 15 chemically defined EOs, alone and in mixture, were checked by a microdilution test against isolates of Penicillium funiculosum and Mucor racemosus cultured from rinds of Marzolino, a typical Italian fresh pecorino cheese. Origanum vulgare yielded the lowest MIC values, followed by Salvia sclarea, Ocimum basilicum and Cymbopogon citratus, while Citrus paradisi and Citrus limon were not active. All mixtures showed antifungal activity at lower concentration with respect to MIC values of each EO component, when not in combination. This study is the first to describe the setting up of EOs mixtures to limit spoiling moulds.

Chemical composition and antifungal activity of essential oils from four Asteraceae plants grown in Egypt.

The objective of the present paper was the assessment of the chemical composition of the essential oils from four Asteraceae species with a considerable food, medicinal, and agricultural value, collected in Egypt, together with their in vitro inhibitory activity against molds and yeasts. The essential oil of Launaea cornuta flowers was also evaluated for the first time, but because of its very low yield (<0.01%), no antifungal test was performed.

Activity of Salvia dolomitica and Salvia somalensis Essential Oils against Bacteria, Molds and Yeasts.

Essential oils (EOs) from Salvia dolomitica and Salvia somalensis, widely employed in the cosmetic and perfume industry, were analyzed for composition and tested against bacterial and fungal pathogens isolated from clinical and environmental specimens. The analyses were carried out against Staphylococcus aureus, Staphylococcus pseudointermedius, Pseudomonas aeruginosa, Escherichia coli, Streptococcus canis, Streptococcus pyogenes, Klebsiella pneumoniae, Proteus mirabilis, Microsporum canis, Microsporum gypseum, Trichophyton mentagrophytes, Aspergillus niger, Aspergillus flavus, Candida albicans, Candida krusei, Mucor sp. and Trichothecium roseum. Both EOs showed similar percentages of total monoterpenes and sesquiterpene hydrocarbons. The main constituents were 1,8-cineole and ß-caryophyllene in S. dolomitica and bornyl acetate and camphor in S. somalensis. The selected EOs have no relevant antifungal or antibacterial activities if compared to conventional drugs.

Stonebrood and chalkbrood in Apis mellifera causing fungi: in vitro sensitivity to some essential oils.

Aim of the present study was to evaluate the in vitro antimycotic activity of 17 chemically defined essential oils (EOs) both alone and as a mixture, against agents responsible for stonebrood caused by Aspergillus flavus, and chalkbrood caused by Ascosphaera apis in European honeybees. Cinnamomum zeylanicum yielded the lowest MIC value against A. flavus, but was not effective against A. apis, while Litsea cubeba and Pelargonium graveolens appeared to be effective against all checked fungi. Aspergillus niger showed the lower sensitivity. Two mixtures composed by L. cubeba, C. zeylanicum and Cymbopogon flexuosus (M1) and by L. cubeba, C. zeylanicum, P. graveolens and C. flexuosus (M2), respectively, were tested, both resulting effective. The components of M1 showed a synergistic effect. The use of mixtures allowed to decrease the total amount of EOs. The use of these products could be of interest for an alternative natural approach in honeybee disease management.

Traditional Mediterranean plants: characterization and use of an essential oils mixture to treat Malassezia otitis externa in atopic dogs.

Several plants extracts from Mediterranean countries are traditionally employed in skin troubles both in humans and in animals. Malassezia pachydermatis is a lipophylic yeast responsible for otitis externa and dermatitis in dogs and for cutaneous and systemic disease in humans. Five mixtures of essential oils obtained from Mediterranean plants (Citrus paradisi, Salvia sclarea, Ocimum basilicum, Rosmarinus officinalis, Citrus limon, Anthemis nobilis, Lavandula hybrida and Thymus vulgaris) provided with antifungal and/or anti-inflammatory action assayed in vitro, were tested in vivo versus M. pachydermatis to treat once daily for 2 weeks 25 atopic dogs with Malassezia otitis externa. Mixture composed by C. limon 1%, S. sclarea 0,5%, R. officinalis 1%, A. nobilis 0,5% yielded excellent results in all treated dogs. Despite of clinical resolution after all treatments the number of blastospores did not decrease. This study confirms recent findings suggesting a multifactorial alternative approach for the management of canine Malassezia otitis.

Open-field study comparing an essential oil-based shampoo with miconazole/chlorhexidine for haircoat disinfection in cats with spontaneous microsporiasis.

Objectives The goal of the present study was to compare the antifungal efficacy of an essential oil (EO) shampoo proven to be effective against Microsporum canis with miconazole/chlorhexidine for topical haircoat disinfection in cats treated concurrently with oral itraconazole. Methods Cats received treatment with oral itraconazole (Itrafungol) at a dose of 5 mg/kg/day pulse administration for 1 week, every 2 weeks for at least 6 weeks and were washed twice a week with a neutral shampoo with added EOs of Thymus serpyllum (2%), Origanum vulgare and Rosmarinus officinalis (5% each) for the period of systemic treatment. This protocol was compared with a conventional treatment (oral itraconazole + 2% miconazole/2% chlorhexidine shampoo). Results The treatment was well tolerated and adverse effects were not recorded. All cats were clinically negative at week 11. With respect to animals with extensive lesions, the speed of resolution was higher in cats with focal lesions. The animals showing diffuse lesions required more than a course of treatment to achieve a mycological cure. There was no significant difference between the number of weeks to obtain mycological cure for cats treated with EOs and animals treated conventionally. Conclusions and relevance The treatment appeared to be effective and well appreciated by the owners. The use of shampoo with the added EOs of T serpyllum, O vulgare and R officinalis would seem an interesting, natural alternative to conventional topical treatment.

Occurrence of moulds from bee pollen in Central Italy--A preliminary study.

The present study aimed to preliminary evaluate the occurrence of fungi in 40 specimens of trapped pollen collected from April-September 2015 in 40 apiaries from Tuscany (Central Italy). Cultural and microscopical examinations allowed the recognition of Cladosporium sp., Alternaria sp., Humicola sp. Mucoraceae and Acremonium sp. Penicillium brevicompactum, Penicillium chrysogenum, Aspergillus flavus , Aspergillus nidulans, Aspergillus niger and Aspergillus terreus were also identified. Yeasts and Fusarium spp. were not isolated. All pollen specimens were positive for at least one fungal isolate. Total CFU per gram ranged from 4-568. Aspergillus and Penicillium were obtained from 8 (20%) and from 22 (55%) pollen samples, respectively, associated in 4 cases (10%). The recovery of storage fungi such as Aspergillus and Penicillium in trapped pollen presents a potential risk for human health and attention should be paid to all stages of the post-harvest process.

In Vitro Activity of Twenty Commercially Available, Plant-Derived Essential Oils against Selected Dermatophyte Species.

The in vitro activity of twenty chemically defined essential oils (EOs) obtained from Boswellia sacra, Citrus bergamia, C. limon, C. medica, Cinnamomum zeylanicum, Eucalyptus globulus, Foeniculum vulgare, Helichrysum italicum, Illicium verum, Litsea cubeba, Mentha spicata, Myrtus communis, Ocimum basilicum, Origanum majorana, O. vulgare, Pelargonium graveolens, Rosmarinus officinalis, Santalum album, Satureja montana, and Thymus serpyllum was assayed against clinical animal isolates of Microsporum canis, Trichophyton mentagrophytes, T. erinacei, T. terrestre and Microsporum gypseum, main causative agents of zoonotic and/or environmental dermatophytoses in humans. Single main components present in high amounts in such EOs were also tested. Different dermatophyte species showed remarkable differences in sensitivity. In general, more effective EOs were T. serpyllum (MIC range 0.025%-0.25%), O. vulgare (MIC range 0.025%-0.5%) and L. cubeba (MIC range 0.025%-1.5%). F. vulgare showed a moderate efficacy against geophilic species such as M gypseum and T terrestre. Among single main components tested, neral was the most active (MIC and MFC values 5 0.25%). The results of the present study seem to be promising for an in vivo use of some assayed EOs.

A herbal antifungal formulation of Thymus serpillum, Origanum vulgare and Rosmarinus officinalis for treating ovine dermatophytosis due to Trichophyton mentagrophytes.

A number of herbal products with anti-inflammatory, antiseptic and antimycotic properties are available for dermatological usage. The successful treatment of 13 sheep affected by ringworm due to Trichophyton mentagrophytes with a mixture consisting of essential oils (EOs) of Thymus serpillum 2%, Origanum vulgare 5% and Rosmarinus officinalis 5% in sweet almond (Prunus dulcis) oil. The effectiveness of EOs and of the major components of the mixture (thymol, carvacrol, 1,8 cineole, α-pinene, p-cymene, γ-terpinene) against the fungal clinical isolate was evaluated by a microdilution test. Thirteen animals were topically administered with the mixture twice daily for 15 days. The other sheep were administered with a conventional treatment (seven animals) or left untreated (two animals). Minimum inhibitory concentration (MIC) values were 0.1% for T. serpillum, 0.5% for O. vulgare, 2.5% for I. verum and 5% for both R. officinalis and C. limon. Thymol and carvacrol showed MICs of 0.125% and 0.0625%. A clinical and aetiological cure was obtained at the end of each treatment regimen in only the treated animals. Specific antimycotic drugs licenced for food-producing sheep are not available within the European Community. The mixture tested here appeared to be a versatile tool for limiting fungal growth.