RESUMO
OBJECTIVES: The human skin microbiota is mainly composed of bacteria belonging to the genera Staphylococcus, Cutibacterium, Micrococcus and Corynebacterium, but on the skin of the face and back, ca. 50% of the total microbiota is represented by the bacterium Cutibacterium acnes. The aim of this research was to evaluate the impact of C. martini EO and its major compound, geraniol, on C. acnes. METHODS: The minimum inhibitory concentration against C. acnes strains, phenotypic changes and responses of the proteome was determined. In addition, was assessed the effect of compounds in RNA-binding assay, on C. acnes-exposed keratinocytes and on the C. acnes type distribution on shoulder skin. KEY FINDINGS: The range of the MIC was 0.7 to 1.6 mg/ml for the three main C. acnes types. There were no cytotoxic effects of compounds in the absence or presence of C. acnes; after 7 days of exposure to C. martini EO, we could not detect a major shift of the C. acnes types on shoulder skin that was found to be dominated by C. acnes strains of types II and IA2. CONCLUSIONS: Our work gives novel insight into the skin microbiota-interacting properties of C. martini EO.
Assuntos
Cymbopogon , Queratinócitos/efeitos dos fármacos , Óleos Voláteis/farmacologia , Propionibacterium acnes/efeitos dos fármacos , Monoterpenos Acíclicos , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Óleos Voláteis/administração & dosagem , Pele/efeitos dos fármacos , Terpenos/administração & dosagem , Terpenos/farmacologiaRESUMO
The recent decline of Apis mellifera populations around the world has been subject of intense research due to ecological and economic damages resulting from the loss of pollination services. The intensive use of insecticides from the neonicotinoids group is among the possible causal factors of this decline, including also sub-lethal effects. However, the use of synthetic insecticides has been increased on a global scale in the recent decades. In order to evaluate an alternative to the use of neonicotinoids, this work investigated the effects of a bioinsecticide and its major compound on A. mellifera (Apidae: Hymenoptera), one of the main pollinators of crop plants. For this, bees were exposed, by contact and ingestion, to the essential oil of Cymbopogon martinii (Poaceae: Poales), to geraniol (major compound) and the insecticide imidacloprid to evaluate the toxicity and behavioral effects as well as the locomotion changes and immune responses of bees treated with these compounds. In general, toxicity was greater through ingestion and the insecticide imidacloprid was more toxic to A. mellifera compared to the essential oil and its major compound. The individual and collective behaviors (i.e. trophallaxis, grooming, avoidance) as well as the immune responses of bees were not significantly affected by bioinsecticides. However, the locomotion response and flight orientation of the bees were significantly altered by insecticide when administered by ingestion. Our results highlight the potential of C. martinii essential oil and its major compound as a possible alternative to mitigate the harmful effects of neonicotinoids on bees.
Assuntos
Abelhas/efeitos dos fármacos , Cymbopogon , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Óleos Voláteis/toxicidade , Terpenos/toxicidade , Monoterpenos Acíclicos , Animais , Abelhas/fisiologia , Comportamento Animal/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Polinização/efeitos dos fármacosRESUMO
OBJECTIVES: In traditional medicine, plants have formed the basis of sophisticated systems that have been in existence for thousands of years and still provide mankind with new remedies. Cymbopogon martinii, known as palmarosa, has been used in aromatherapy as a skin tonic due to its antimicrobial properties. It has also used in Ayurvedic medicine for skin problems and to relieve nerve pain. The immunomodulatory action of C. martinii essential oil (EO) and geraniol was evaluated regarding the production of pro- and anti-inflammatory cytokines (tumour necrosis factor (TNF)-α and IL-10, respectively) by human monocytes in vitro. METHODS: Monocyte cultures were incubated with EO or geraniol. After 18 h, cytotoxicity assays were performed using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method, and cytokine production was determined by ELISA. KEY FINDINGS: The variables showed no cytotoxic effects on monocytes. TNF-α production was not affected by C. martinii and geraniol, and only the concentration of 5 µg/ml of C. martinii stimulated its production. On the other hand, all concentrations of C. martinii and geraniol increased IL-10 production by human monocytes. CONCLUSIONS: Data showed that noncytotoxic concentrations of EO and geraniol exerted an anti-inflammatory action by increasing IL-10 production; moreover, geraniol seemed to be probably responsible for EO immunomodulatory activity in our assay condition.
Assuntos
Anti-Inflamatórios/farmacologia , Cymbopogon/química , Fatores Imunológicos/farmacologia , Interleucina-10/metabolismo , Monócitos/efeitos dos fármacos , Óleos Voláteis/farmacologia , Terpenos/farmacologia , Monoterpenos Acíclicos , Adulto , Humanos , Pessoa de Meia-Idade , Monócitos/metabolismo , Óleos Voláteis/química , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto JovemRESUMO
Essential oils of C. citratus, C. nardus, C. flexuosus y C. martinii, cultivated in experimental plots in Bucaramanga, Colombia, were subjected to a comparative study of their compositions. The essential oils were obtained by means of microwave radiation-assisted hydrodistillation from freshly cut leaves. Component identification was performed by GC-MS analysis and their quantification employed GC-FID, with n-tetradecane as internal standard. A calibration curve was employed for each main constituent. The most abundant components were geranial (46,3 percent), neral (32,88 percent) and beta-myrcene (10,5 percent) in C. citratus; citronellal (45,7 percent), geraniol (20,4 percent) and citronelol (9,9 percent) in C. nardus; geranial (50,2 percent) and neral (28,7 percent) in C. flexuosus and geraniol (69,6 percent) and geranyl acetate (15,6 percent) in C. martinii. Extraction yields were 0,46, 1,06, 0,46 and 1,2 percent for C. citratus, C. nardus, C. flexuosus and C. martinii, respectively. The observed relative amounts of the most abundant constituent in C. martinii, C. flexuosus and C. citratus oils were similar to those found in oils of the same species in India.
En este trabajo se realizó el estudio comparativo de la composición de los aceites esenciales de C. citratus, C. nardus, C. flexuosus y C. martinii, cultivadas en parcelas experimentales en Bucaramanga1, Colombia. Los aceites esenciales se obtuvieron mediante hidrodestilación asistida por radiación de microondas de hojas frescas de cada especie. La identificación de los componentes presentes en los aceites se realizó por medio de análisis por GC-MS, y la cuantificación de estos componentes se realizó por GC-FID, utilizando n-tetradecano como estándar interno y una curva de calibración para los componentes mayoritarios. Los componentes presentes en mayor proporción en los aceites fueron: geranial (46,3 por ciento), neral (32,88 por ciento) y beta-mirceno (10,5 por ciento) en C. citratus; citronellal (45,7 por ciento), geraniol (20,4 por ciento) y citronelol (9,9 por ciento) en C. nardus; geranial (50,2 por ciento) y neral (28,7 por ciento) en C. flexuosus y geraniol (69,6 por ciento) y acetato de geranilo (15,6 por ciento) en C. martinii. El rendimiento de extracción fue 0,46 por ciento en C. citratus; 1,06 por ciento en C. nardus, 0,46 por ciento en C. flexuosus y 1,2 por ciento en C. martinii. La proporción del componente mayoritario presente en el aceite esencial de C. martinii, C. flexuosus y C. citratus fue similar a la obtenida en los aceites, de estas mismas mismas especies, producidos en India.