The inclusion of oregano essential oil, alone or associated with salinomycin, was evaluated as an alternative to zinc bacitracin on the performance of broiler chickens. This study used 600 male Cobb ...500® day-old chicks, raised 42 days in boxes with rice hulls, provided with tubular feeders and nipple drinkers. The experimental design was completely randomized with six diets and 10 replications with 10 birds per experimental unit. The diets were based on corn and soybean meal: positive control - antibiotic (zinc bacitracin) + 0.05% anticoccidial (salinomycin), negative control - basal diet (BD) without additives, DB + 0.05% of salinomycin and 0.03% of oregano essential oil (Orego-Stim®),
DB + 0.03% of oregano essential oil, DB + 0.05% of salinomycin and 0.05% of oregano essential oil, DB + 0.05% of oregano essential oil. There were no treatment effects on broiler performance until 21 days of age. In the other periods, at 35 and 42 days, the oregano essential oil at 0.03% combined with salinomycin presented similar effects as the positive
control, leading to the conclusion that 0.03% of oregano essential oil associated with the salinomycin can replace zinc bacitracin + salinomycin in broiler chicken diets.
O presente trabalho teve como objetivo avaliar dietas com óleo essencial de orégano, associado ou não com salinomicina, como alternativa à bacitracina de zinco sobre o desempenho zootécnico de frangos de corte. Foram utilizados 600 pintos de um dia de idade, machos, da linhagem Cobb® 500, criados até 42 dias de idade em boxes com cama de casca de arroz providos de comedouros tubulares e bebedouros nipple. O delineamento foi inteiramente casualizado, com seis dietas e 10 repetições de 10 aves cada. As dietas experimentais à base de milho e farelo de soja foram: controle positivo – antibiótico (bacitracina de zinco) + 0,05% de anticoccidiano (salinomicina), controle negativo – dieta basal (DB) sem aditivos, DB + 0,05% de salinomicina e 0,03% de óleo essencial de orégano (Orego-Stim®), DB + 0,03% de óleo essencial de orégano, DB + 0,05% de salinomicina e 0,05% de óleo essencial de orégano, DB + 0,05% de óleo essencial de orégano. Não foi encontrado efeito da utilização do óleo de orégano até 21 dias no desempenho das aves. Nos demais períodos, aos 35 e 42 dias, o desempenho das aves tratadas com 0,03% de óleo essencial de orégano + salinomicina apresentou resultados semelhantes ao controle positivo, levando à conclusão de que a dose de 0,03% de óleo essencial de orégano + salinomicina pode substituir a bacitracina de zinco + salinomicina em dietas para frangos de corte.
Objetivo: evaluar la actividad antimicrobiana de cinamaldehído, timol, eugenol y quitosano en comparación con clorhexidina al 0,12 % sobre cepas de Streptococccus mutans. Métodos: se realizaron ...pruebas de susceptibilidad bacteriana de cepas de Streptococccus mutans con discos embebidos en eugenol, cinamaldehído, quitosano y timol, al 0,1 y 1 % con un control positivo de clorhexidina al 0,12 % evaluando los halos de inhibición existentes a las 24 h y 48 h. Resultados: el cinamaldehído al 1 % mostró el mejor poder de control sobre el crecimiento de Streptococccus mutans al presentar 19,91 mm y 24,44 mm de halos de inhibición a las 24 h y 48 h, respectivamente, con una diferencia significativa de p< 0,05 entre los dos intervalos. Cuando se comparó el cinamaldehído al 1 % con el control positivo de clorhexidina al 0,12 %, no se encontraron diferencias significativas (p> 0,05). Conclusiones: el cinamaldehído al 1 % tuvo los mejores resultados seguidos por quitosano, eugenol y timol a la misma concentración en comparación con clorhexidina al 0,12 % tanto a la 24 como 48 h.
A presença de uma microbiota benéfica no trato gastrointestinal é um fator importante na otimização da digestão e absorção dos nutrientes indispensável para se obter boa produtividade. Neste sentido, ...a utilização de antimicrobianos promotores de crescimento na ração dos animais de produção tem como objetivo promover a redução e/ou a morte dos micro-organismos indesejáveis. No entanto, devido à possibilidade de resistência cruzada novas alternativas vêm sendo pesquisadas em substituição a esses antimicrobianos, tais como os óleos essenciais aromáticos. Estes apresentam poucos riscos de acúmulos nos tecidos devido à rápida metabolização e curta meia-vida dos seus compostos ativos, sendo que podem atuar diretamente sobre micro-organismos patogênicos. Assim, podem atuar como promotores de crescimento e possivelmente substituir os antibióticos e promotores de crescimento comumente utilizados na dieta dos animais. Os compostos fenólicos, carvacrol e timol, componentes majoritários do óleo essencial de Lippia gracillis Shauer, são os principais responsáveis pela ação antimicrobiana e antioxidante do óleo. No entanto, há poucas pesquisas para avaliar o efeito deste aditivo como promotor de crescimento. Deste modo, devido à potencialidade que estes compostos ativos apresentam diante de bactérias patogênicas e fungos, sua atividade antioxidante, assim como seu potencial como melhoradores de desempenho, o óleo essencial do alecrim torna-se um potencial aditivo para ser adicionado às dietas de aves. Objetivou-se com esse artigo de revisão elucidar o modo de ação do óleo essencial de alecrim (Lippia gracillis Shauer) sobre a microbiota intestinal das aves como antimicrobianos melhoradores de desempenho.
Thymol is a monoterpene and acetylation form of this compound can reduce the toxicity and enhance its biological effects. The objective of this study was to evaluate the effect of thymol and thymol ...acetate (TA) on egg, larva and adult Haemonchus contortus and the cuticular changes, acute toxicity in mice and the efficacy on sheep gastrointestinal nematodes. In vitro tests results were analyzed by analysis of variance (ANOVA) and followed by comparison with Tukey test or Bonferroni. The efficacy of in vivo test was calculated by the BootStreet program. In the egg hatch test (EHT), thymol (0.5 mg/mL) and TA (4 mg/mL) inhibited larval hatching by 98% and 67.1%, respectively. Thymol and TA (8 mg/mL) inhibited 100% of larval development. Thymol and TA (800 µg/mL) reduced the motility of adult worms, by 100% and 83.4%, respectively. Thymol caused cuticular changes in adult worm teguments. In the acute toxicity test, the LD50 of thymol and TA were 1,350.9 mg/kg and 4,144.4 mg/kg, respectively. Thymol and TA reduced sheep egg count per gram of faeces (epg) by 59.8% and 76.2%, respectively. In in vitro tests thymol presented better anthelmintic activity than TA. However TA was less toxic and in in vivo test efficacy was similar.
This study aimed to evaluate the effect of oregano oil on the intestinal and liver morphometry of yellow tail tetra, Astyanax altiparanae. Fish (1.46 ± 0.09 g) were kept in a 60-L aquaria, at a ...stocking density of 0.5 fi sh L-1. Six diets containing varying amounts of oregano oil were evaluated (0.0; 0.5; 1.0; 1.5; 2.0 and 2.5 g of oregano oil kg-1). At the end of 90 days, the fi sh were euthanised. Four intestines and four livers were collected per treatment, which were fi xed in Bouin and embedded in resin. For height and width folds, the absorption surface area and thickness of the muscular layer a positive linear effect of oregano oil was observed. A decrescent linear effect on the total number of goblet cells was also observed. For the cytoplasmic percentage of hepatocytes and liver glycogen, a positive linear effect of oregano oil was observed. There was a decreasing linear effect on the percentage of nuclei in the hepatocytes and capillaries. Thus, the oregano essential oil promotes increased absorption areas, modulates the amount of goblet cells involved in protecting the intestinal mucosa and promotes cytoplasmic increase with greater deposition of liver glycogen in yellow tail tetra.
The aim of this study was to evaluate the antifungal activity (in vitro) of thymol and carvacrol alone or in mixtures against Fusarium verticillioides and Rhizopus stolonifer, and to obtain primary ...growth models. Minimal inhibitory concentration (MIC) was evaluated with fungal radial growth with thymol or carvacrol concentrations (0–1600mg/l). Mixtures were evaluated using concentrations below MIC values. Radial growth curves were described by the modified Gompertz equation. MIC values of carvacrol were 200mg/l for both fungi. Meanwhile, MIC values of thymol were between 500 and 400mg/l for F. verticillioides and R. stolonifer, respectively. A synergistic effect below MIC concentrations for carvacrol (100mg/l) and thymol (100–375mg/l) was observed. Significant differences (p<0.05) between the Gompertz parameters for the antimicrobial concentrations and their tested mixtures established an inverse relationship between antimicrobial concentration and mycelial development of both fungi. Modified Gompertz parameters can be useful to determine fungistatic concentrations.
El objetivo de este trabajo fue evaluar la actividad antifúngica in vitro del timol y del carvacrol, solos o en mezclas, contra Fusarium verticillioides y Rhizopus stolonifer, y obtener modelos primarios de crecimiento. Se evaluó la concentración inhibitoria mínima (CIM) con el crecimiento radial, se ensayaron concentraciones de timol y carvacrol de 0 a 1.600mg/l. Las mezclas se evaluaron utilizando concentraciones por debajo de los valores de CIM. Las curvas de crecimiento radial fueron descritas por la ecuación de Gompertz modificada. Se obtuvieron los siguientes valores de CIM: carvacrol, 200mg/l para las 2 especies; timol, 500mg/l y 400mg/l para F. verticillioides y R. stolonifer, respectivamente. Se observó un efecto sinérgico a concentraciones inferiores a las CIM para el carvacrol (100mg/l) y el timol (100-375mg/l). Hubo diferencias significativas (p<0,05) entre los parámetros de crecimiento de Gompertz; se estableció que existe una relación inversa entre la concentración de los antimicrobianos y el desarrollo del micelio de ambos hongos.
A test was conducted under field conditions at the Universidad Nacional de Colombia sede Palmira and oils analysis in the Universidad Industrial de Santander (UIS), in order to determine the effect ...of plant age at the time cutting and the effect of drying the plant material on the composition and concentration of the essential oils of three accessions of Lippia origanoides Kunth. (Patía, Cítrica and Típica) and two accessions of Lippia alba (Mill.) N.E.Br. ex Britton & P. Wilson (Cítrica and Típica). In a split plot arrangement with three replications, two factors were evaluated drying and three harvest times. The results showed that drying increased the concentration of the main components of the accessions of the two Lippia species, and age of the plants at harvest did not affect the composition and concentration of essential oils.
Se evaluó la eficacia del humo de los frutos secos de Guazuma ulmifolia y los vapores de timol en el control del ácaro Varroa destructor infestando colonias de abejas africanizadas (Apis mellifera) ...de Yucatán. Se utilizaron tres tratamientos: Grupo 1 (G1), las colonias de abejas recibieron 5 a 8 bocanadas de humo de los frutos secos de G. ulmifolia dos veces por semana, durante un período de tres semanas; Grupo 2 (G2), las colonias recibieron 4-8 g de cristales de timol con tres aplicaciones cada siete días, y Grupo 3 (G3 o grupo control) las colonias no recibieron ningún tratamiento durante las tres semanas del experimento. Se colectaron 200 a 300 abejas adultas de cada colonia previo a la aplicación de los tratamientos (día 0) y a los 7, 14 y 21 días después de las aplicaciones, con la finalidad de determinar los niveles de infestación y eficacia de los tratamientos. Los resultados indican que los niveles de infestación de V. destructor en las abejas adultas disminuyeron al final del experimento (21 días) y fueron estadísticamente diferentes para los tres tratamientos, siendo menor para G2. La eficacia al final de los tratamientos fue de 41 y 69 %, para G1 y G2, respectivamente. Estos resultados corroboran que la aplicación de cristales de timol es una alternativa para el control del ácaro V. destructor en Yucatán, y que la aplicación del humo de los frutos secos de G. ulmifolia reduce los niveles de infestación de este parásito en comparación con las colonias que no recibieron ningún tipo de tratamiento (G3).
The mite Varroa destructor is a scourge in honey bee colonies worldwide. Conventional chemical-based control treatments can contaminate colony products and cause resistance in the parasite. Plant-source compounds are promising alternatives. The effectiveness of smoke from dried Guazuma ulmifolia fruit and vapors from thymol crystals was evaluated in control of V. destructor in colonies of Africanized bees (Apis mellifera) in Yucatan, Mexico. Three treatments were used during a three-week experimental period. In Group 1, colonies were administered five to eight puffs of smoke from dried G. ulmifolia fruits twice a week. In Group 2, they were administered 4-8 g of thymol crystals once a week. Group 3 was a control and received no treatment. Collections of 200 to 300 adult bees from each colony were done prior to treatment (day 0) and after treatment at 7, 14 and 21 d. These were processed to quantify colony infestation levels and treatment efficacy. Overall V. destructor infestation levels in adult bees decreased in all three groups after 21 d, with differences between treatments. Levels were lowest in Group 2, followed by Group 1 and the control. Efficacy at the end of the treatments was 41 % in Group 1 and 69% in Group 2. Compared to the control, application of thymol crystals provided the most effective alternative control method against V. destructor. However, regular application of G. ulmifolia fruit smoke also reduced mite infestation levels, and this resource has the advantage of being locally available.
Objetivo: Determinar el efecto espasmolítico del timol, principal compuesto del aceite esencial de Thymus Vulgaris “Tomillo”, en útero aislado de ratas blancas hembras vírgenes Holtzman. Diseño: ...Estudio experimental in vitro. Lugar: Sección de Farmacología de la Facultad de Medicina “San Fernando”, Universidad Nacional Mayor de San Marcos - Lima, Perú. Material biológico: Timol, el cual se obtuvo del laboratorio Sigma-Adrich® y ratas blancas hembras vírgenes Holtzman. Método: La actividad espasmolítica fue evaluada in vitro usando el método experimental en órgano aislado en muestras de útero de rata. Se registraron las contracciones basales del útero, se indujo a mayores contracciones aplicando oxitocina y se realizaron ensayos de dosis-respuesta para la reducción de dichas contracciones administrándose el timol a dosis progresivas de 0.2 ml ,0.4 ml, 0.6 ml a fin de obtener la dosis necesaria para la disminución de las contracciones. Resultados: Dosis incrementales de 0,2 ml, 0,4 ml y 0,6 ml de Timol, mostraron un efecto relajante sobre las contracciones inducidas por la oxitocina de manera proporcional a la dosis administrada, siendo la dosis de 0,6 ml de Timol la que mostró un mayor efecto en la reducción de las mismas. Conclusión: El timol demostró tener un efecto espasmolítico en el útero aislado de rata virgen al disminuir las contracciones inducidas por oxitocina.
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