Aceite esencial de hojas de Minthostachys mollis [HBK] Griseb. del Ecuador: extracción, composición química, capacidad antioxidante y actividad antimicrobiana / Essential oil of Minthostachys mollis [HBK] Griseb. leaves from Ecuador: extraction, chemical composition, antioxidant capacity and antimicrobial activity

The aim of this study was to optimize by response surface design, the extraction of the leaf essential oil (EO) from Minthostachys mollis [HBK] Griseb., grown in Ecuador, using steam distillation. The factors used were extraction time (XTIE) of 60, 105 and 150 min and plant material/water ratio (XRMA) of 1:3, 1:4 and 1:5. The optimal combination was reached with XRMA 1:5 and XTIE 150 min, obtaining a process yield of 0.67%. The chemical composition of the EO analyzed by GC - MS was determined, where the main compounds were carvacryl acetate (44.01%), carvacrol (16.51%) and menthone (8.20%). The anti oxidant capacity of EO was evaluated using the FRAP and ABTS methodologies, with an IC 50 243.21 µmol Fe 2+ /g and 0.12 mg/mL, respectively. In addition, the antimicrobial activity of EO was found against Pseudomonas aeruginosa , Salmonella enterica , Escherich ia coli and Staphylococcus aureus .

El objetivo del estudio fue optimizar, mediante un diseño de superficie respuesta, la extracción d el aceite esencial (AE) de hojas de Minthostachys mollis [HBK] Griseb. del Ecuador, mediante destilación por arrastre de vapor. Los factores fueron el tiempo de extracción (XTIE) de 60, 105 y 150 min, y relación de material vegetal/ agua destilada (XRMA) d e 1:3, 1:4 y 1:5. La combinación óptima se logró con XTIE 150 min y XRMA 1:5 para un rendimiento de 0,67%. Se determinó la composición química del AE por GC - MS donde los compuestos mayoritarios fueron acetato de carvacrilo (44,01%), carvacrol (16,51%) y me ntona (8,20%). Se evaluó la capacidad antioxidante del AE por las metodologías FRAP y ABTS, con CI 50 de 243,21 µmol Fe 2+ /g y 0,12 mg/mL, respectivamente. Además, se demostró la actividad antimicrobiana contra Pseudomonas aeruginosa , Salmonella enterica , Es cherichia coli y Staphylococcus aureus .

Somatic growth effects of intramuscular injection of growth hormone in androgen-treated juvenile Nile tilapia, Oreochromis niloticus (Perciformes: Cichlidae).

Little is known about the effects of the interaction of growth hormone (GH) with 17 alpha-methyltestosterone (17-MT) during fish growth. We evaluated this in the present study to assess the effect on fish growth. Fish in two batches of juvenile tilapia (Oreochromis niloticus) (approximately 5.0cm in length) were randomly assigned in triplicate to three treatments and a control group, distributed among 12 fiberglass tanks of 1 000L capacity (50 fish per tank) in an experiment covering a period of six weeks. The experimental groups were: a) fish treated with 17-MT and GH in mineral oil (RGH); b) fish treated with 17-MT and mineral oil without the addition of GH (R); c) fish treated with GH in mineral oil but not 17-MT (NGH); and d) fish of the control group, which were treated with mineral oil but not 17-MT or GH (N). The GH was injected into the fish at a rate of 0.625mg/g body weight. Morphometric data were recorded at the beginning of the experiment (T0) and at 15, 30 and 45 days (T15, T30 and T45), and various indicators of growth were assessed: condition factor (K); survival percentage (S), feed conversion rate (FCR), percentage weight gain (WG) and (v) daily weight gain. The optimum dietary level was calculated assuming 5% food conversion to total weight in each group. During the experiment, the fish were provided with a commercial food containing 45% protein. The data showed that GH injection resulted in a greater weight gain in fish treated with 17-MT (the RGH treatment group), being particularly significant increase in weight during T15 and T30 (p<0.05). High values of K were found in the R and RGH treatments during the initial days of the experiment, which may have been a consequence of the better nutritional status affecting both weight gain and growth in body length, as a result of the additive effects of 17-MT and GH. The fish in groups not treated with 17-MT and treated with 17-MT and added GH showed greater increases in WG per day, higher K values and lower FCRs than fish in the other groups, which suggests that greater feed efficiency occurred in the hormone-treated fish. Fish in the RGH treatment showed the most growth, suggesting a possible interaction between 17-MT and injected GH.

Somatic growth effects of intramuscular injection of growth hormone in androgen-treated juvenile Nile tilapia, Oreochromis niloticus (Perciformes: Cichlidae)

Little is known about the effects of the interaction of growth hormone (GH) with 17 a-methyltestosterone (17-MT) during fish growth. We evaluated this in the present study to assess the effect on fish growth. Fish in two batches of juvenile tilapia (Oreochromis niloticus) (approximately 5.0cm in length) were randomly assigned in triplicate to three treatments and a control group, distributed among 12 fiberglass tanks of 1 000L capacity (50 fish per tank) in an experiment covering a period of six weeks. The experimental groups were: a) fish treated with 17-MT and GH in mineral oil (RGH); b) fish treated with 17-MT and mineral oil without the addition of GH (R); c) fish treated with GH in mineral oil but not 17-MT (NGH); and d) fish of the control group, which were treated with mineral oil but not 17-MT or GH (N). The GH was injected into the fish at a rate of 0.625mg/g body weight. Morphometric data were recorded at the beginning of the experiment (T) and at 15, 30 and 45 days (T, T and T), and various indicators of growth were assessed: condition factor (K); survival percentage (S), feed conversion rate (FCR), percentage weight gain (WG) and (v) daily weight gain. The optimum dietary level was calculated assuming 5% food conversion to total weight in each group. During the experiment, the fish were provided with a commercial food containing 45% protein. The data showed that GH injection resulted in a greater weight gain in fish treated with 17-MT (the RGH treatment group), being particularly significant increase in weight during T and T (p<0.05). High values of K were found in the R and RGH treatments during the initial days of the experiment, which may have been a consequence of the better nutritional status affecting both weight gain and growth in body length, as a result of the additive effects of 17-MT and GH. The fish in groups not treated with 17-MT and treated with 17-MT and added GH showed greater increases in WG per day, higher K values and lower FCRs than fish in the other groups, which suggests that greater feed efficiency occurred in the hormone-treated fish. Fish in the RGH treatment showed the most growth, suggesting a possible interaction between 17-MT and injected GH.

Actualmente, durante el crecimiento de los peces existe poco conocimiento sobre los efectos de la interacción de la hormona del crecimiento (HC) con 17 α-metiltestosterona (17-MT). En el presente estudio los peces en dos lotes de tilapia (Oreochromis niloticus) (5.0cm de longitud), fueron asignados al azar por triplicado a tres tratamientos y un grupo control, distribuidos en 12 tanques de fibra de vidrio de 1 000 litros (50 peces por tanque), en un período de seis semanas. Los tratamientos fueron: a) peces tratados con 17-MT+HC en aceite mineral (RGH), b) peces tratados con 17-MT+aceite mineral sin la adición de HC (R), c) los peces que no fueron tratados con 17-MT-tratado+HC en aceite mineral (NGH), y d) los peces que no fueron tratados con 17-MT+aceite mineral (N). La hormona de crecimiento humano recombinante (Humatrope, Eli Lilly & Co., Windlesham, Inglaterra), se inyectó en el pez con una dosis de 0.625mg por gramo de peso corporal. Los datos morfométricos se registraron al comienzo del experimento (T) y en los días 15, 30 y 45 (T, T y T), Se registraron diversos indicadores de crecimiento: factor de condición (K), porcentaje de supervivencia (S), la tasa de conversión alimenticia (FCR), porcentaje de ganancia de peso (GP) y el aumento de peso al día. El nivel óptimo dietético fue calculado suponiendo 5% de conversión de alimentos al peso total de cada grupo. Durante el experimento fue usada una dieta comercial con el 45% de proteína. De los resultados presentados, es evidente que la inyección de HC dio lugar a una mayor ganancia de peso en el 17-MT-los peces tratados (el grupo de tratamiento RGH), y la diferencia fue significativa, tanto en T y T (p<0.05) para ambas comparaciones. De manera similar, los altos valores de K se presentaron en los tratamientos R y RGH durante los primeros días de cultivo. Esto puede haber sido asociado con un mejor estado nutricional que afectó tanto el desarrollo de peso y la longitud del cuerpo del pez, como resultado del efecto aditivo de 17-MT y GH. Los tratamientos no andrógenos y los grupos tratados con andrógenos y con HC mostraron un mayor incremento en la ganancia de peso por día, los mayores valores de K y menores tasas de conversión del alimento, lo que sugiere una mayor eficiencia de la alimentación en los peces tratados con hormonas. Peces en el tratamiento RGH mostraron el mayor crecimiento, lo que sugiere una posible interacción entre el 17 de α-metiltestosterona (17-MT) y hormona de crecimiento inyectada.