Activity of Free and Liposome-Encapsulated Essential Oil from Lavandula angustifolia against Persister-Derived Biofilm of Candida auris

The high virulence of Candida auris, a pathogen fungus considered as a global threat for public health, is due to its peculiar traits such as its intrinsic resistance to conventional antifungals. Its biofilm lifestyle certainly promotes the prolonged survival of C. auris after disinfection or antifungal treatments. In this work, for the first time, we detected persister cells in a biofilm of C. auris in a microwell plate model, following caspofungin treatment. Furthermore, we showed how persisters can progressively develop a new biofilm in situ, mimicking the re-colonization of a surface which may be responsible for recalcitrant infections. Plant-derived compounds, such as essential oils, may represent a valid alternative to combat fungal infections. Here, Lavandula angustifolia essential oil, as free or encapsulated in liposomes, was used to eradicate primary and persister-derived biofilms of C. auris, confirming the great potential of alternative compounds against emergent fungal pathogens. As in other Candida species, the action of essential oils against C. auris involves ROS production and affects the expression of some biofilm-related genes.

Óleos essenciais no tratamento de dermatozoonoses – uma revisão de literatura

O uso indiscriminado de medicamentos tem representado uma das maiores ameaças à Saúde Única, haja vista sua atuação na resistência antimicrobiana e seus impactos ao meio ambiente. Assim, busca-se como alternativa sustentável a esses fármacos, os óleos essenciais, substâncias com diversas atividades terapêuticas, destacando a eficácia no tratamento de dermatopatias de origem zoonótica, a exemplo escabiose canina, esporotricose, dermatofitose e leishmaniose tegumentar americana. O presente trabalho tem por objetivo realizar revisão bibliográfica acerca do emprego de óleos essenciais na medicina veterinária, destacando-se o tratamento das dermatopatias de origem zoonótica. Foi demonstrado o efeito acaricida, fungicida e fungistático dos óleos essenciais de Melaleuca alternifolia, Cedrus deodara, Azadirachta indica, Myrtus communis, Thymus vulgaris, Rosmarinus officinalis, Lavandula angustifolia, Cinnamomum cassia, Eugenia uniflora e Plectranthus amboinicus. As dermatozoonoses apresentam crescente resistência a antifúngicos e antibióticos comerciais, o emprego de terapias alternativas utilizando óleos essenciais se faz relevante de forma a amenizar essa resistência, e proporcionar melhoria na sanidade dos animais. Diante disso, dentre os estudos avaliados é demonstrado que os óleos essenciais de Melaleuca alternifolia, Cedrus deodara, Azadirachta indica, Myrtus communis, Thymus vulgaris, Rosmarinus officinalis, Lavandula angustifolia, Cinnamomum cassia, Eugenia uniflora e Plectranthus amboinicus apresentam resultado in vitro satisfatórios na terapêutica de dermatozoonoses de importância clínica, contudo, se faz necessário a realização de estudos in vivo para verificar a eficácia destes compostos, realizando-se um monitoramento de sua ação mediante as barreiras fisiológicas e metabolismo dos animais.

COMPARISON OF BACTERIAL CELLULOSE PRODUCTION BY KOMAGATAEIBACTER INTERMEDIUS STRAIN USING LAVANDULA ANGUSTIFOLIA, ROSA CANINA AND TILIA CORDATA PLANTS AS LOW-COST MEDIA

In this study, the effects of Lavandula angustifolia, Tilia cordata and Rosa canina on cellulose production by Komagataeibacter intermedius strain were investigated. T. cordata was found as the most effective plant (10.64 g/L BC), under the following optimized conditions: 50 g/L plant amount, 8% lactose, 15% inoculum amount at pH=6.0. Total phenolic contents of L. angustifolia (55.42 mg/g), R. canina (16.54 mg/g) and T. cordata (60.03 mg/g), and total protein amounts of L. angustifolia (7.89 g/L), R. canina (3.54 g/L) and T. cordata (5.13 g/L) were analyzed. It has been established that phenolic and protein substances contribute significantly to cellulose formation. Physicochemical analysis showed that all the peaks obtained from FTIR analysis are distinguishable for BC and pellicles show high thermal stability. This research work is the first report on the usage of L. angustifolia, R. canina and T. cordata plants as low-cost substrates in BC production with high yields.

The impact of soil herbicides on the yield and quality of lavender (Lavandula angustifolia Mill.) essential oil

During the period 2014 – 2015 the herbicidal effect and the selectivity of isoxaflutole (Merlin 750 WG), oxadiargyl (Raft 400 SC), imazamox (Pulsar 40) and flumioxazine (Pledge 50 VP) were studied on lavender fields, Hemus and Jubilejna varieties. The present work focuses on the influence of low doses of the applied preparations on the yield and composition of the essential oil compared with untreated control. The results of two-year studies show that the treated variants have a higher yield on average of 0.7-1.6 kg / dka. The odoriferous ingredients range in the limits: linalyl acetate (20.0 - 38.6 %); linalool (20.6 - 46.2 %); lavandulyl acetate (1.9 - 5.9 %); 1,8 cineole (0,4 - 4,9 %) and camphor (0,2 - 0,6 %). Applying oxidiarigil results in greater changes in the composition of the Jubilejna variety, whereas the Hemus variety has the most influence by isoxaflutole.

Chemical and Biochemical Characterization of Essential Oils and Their Corresponding Hydrolats from Six Species of the Lamiaceae Family

Many plants belonging to the Lamiaceae family are rich in essential oils (EOs) which are intensively used for aromatherapy, food and beverage flavoring, alternative medicine, cosmetics, and perfumery. Aerial parts of Thymus vulgaris L., Thymus pannonicus All., Lavandula angustifolia L., Lavandula x intermedia, Origanum vulgare L., and Origanum vulgare var. aureum L. were subjected to hydrodistillation, and both resulting fractions were analyzed. The purpose of this study was to determine the chemical composition, antioxidant activity, and total phenolic content of six essential oils and their corresponding hydrolats (HDs) through GC-MS and spectrophotometric analyses. Overall, 161 compounds were identified, some found exclusively in essential oils and others in hydrolats, making them individual products with specific end purposes. The total phenolic content was the highest for the Thymus vulgaris L. EOs (3022 ± mg GAE L−1), because of its high phenolic oxygenated monoterpenes content (thymol and carvacrol) and the smallest for the Lavandula angustifolia L. EOs (258.31 ± 44.29 mg GAE L−1), while hydrolats varied from 183.85 ± 0.22 mg GAE L−1 for Thymus vulgaris L. HD and 7.73 mg GAE L−1 for Thymus pannonicus All. HD. Significant antioxidant effects determined through DPPH• and ABTS•+ assays were also observed in samples with higher hydrophilic compounds. The highest antioxidant activity was determined for Thymus vulgaris L. EO and its corresponding HD. Although EOs are the principal traded economic product, HDs represent a valuable by-product that could still present intense antiseptic activities, similar to their corresponding EOs (thyme and oregano), or have multiple aromatherapy, cosmetics, and household applications (lavender and lavandin).