Antimicrobial activity of Tetradenia riparialeaf essential oil / Actividad antimicrobiana del aceite esencial de hoja de Tetradenia riparia

Food spoilage is a widely neglected problem and the constant use of synthetic fungicides could develop resistant fungi. The objective of this study was to evaluate the chemical composition and antimicrobial activity of Tetradenia riparialeaf essential oil against foodborne disease microorganisms. Leaf essential oil was obtained by hydrodistillation and identified by gas chromatography coupled to mass spectrometry. The antimicrobial activity was studied by broth microdilution. The major compounds identified were oxygenated sesquiterpenes (43.6%): 14-hydroxy-9-epi-(E)-cariophylene (20.8%) and τ-cadinol (18.4%); followed by oxygenated diterpenes (24.6%): 6,7-dehydroroyleanone (12.6%) and 9ß, 13ß-epoxy-7-abiethene (10.6%); sesquiterpenic hydrocarbons (17.1%) and oxygenated monoterpenes (7.4%): fenchone (5.6%). The essential oil had broad antibacterial and antifungal activity, mainly against A. versicolor and P. ochrochloron with fungistatic and fungicidal activities and B. cereus, L. monocytogenes, and S. aureuswith bacteriostatic and bactericidal activities. T. riparialeaf essential oil is a potential alternative to control microorganisms-

El deterioro de los alimentos es un problema ampliamente desatendido y el uso constante de fungicidas sintéticos podría desarrollar hongos resistentes. El objetivo de este estudio fue evaluar la composición química y la actividad antimicrobiana del aceite esencial de hoja de Tetradenia riparia contra microorganismos patógenos transmitidos por los alimentos. El aceite esencial de hoja se obtuvo por hidrodestilación y se identificó mediante cromatografía de gases acoplada a espectrometría de masas. La actividad antimicrobiana estudiada fue por microdilución en caldo. Los compuestos principales del aceite esencial se identificaron como sesquiterpenos oxigenados (43,6%): 14-hidroxi-9-epi-(E)-cariofileno (20,8%) y τ-cadinol (18,4%); seguido de diterpenos oxigenados (24,6%): 6-7-deshidroroileanona (12,6%) y 9ß, 13ß-epoxi-7-abieteno (10,6%); hidrocarburos sesquiterpénicos (17,1%) y monoterpenos oxigenados (7,4%): fenchona (5,6%). Tenía amplia actividad antibacteriana y antifúngica, principalmente contra A. versicolor y P. ochrochloron con actividades fungistáticas y fungicidas, y principalmente contra B. cereus, L. monocytogenes y S. aureus con actividades bacteriostáticas y bactericidas. El aceite esencial de hoja de T. riparia es una alternativa potencial para controlar microorganismos.

Crude extract of the tropical tree Gallesia integrifolia (Phytolaccaceae) for the control of Aedes aegypti (Diptera: Culicidae) larvae / Extracto crudo del árbol tropical Gallesia integrifolia (Phytolaccaceae) para el control de larvas de Aedes aegypti (Diptera: Culicidae)

Introduction: Phytoinsecticides are alternatives to control insects in different stages, Gallesia integrifolia (Spreng.) Harms, Phytolacaceae family, popularly known as pau d'alho, garlic tree, and guararema in Brazil, is known due to its strong alliaceous odor because of the presence of sulfur molecules in the plant. This species presents biological activity and potential insecticide effect that is still unexploited. Objective: This study aimed to evaluate the biological activity of the ethanolic crude extract from G. integrifolia leaves, flowers, and fruits on the control of Aedes aegypti third-stage larvae and pupae. Methods: The botanical material was collected in city Umuarama, Paraná, Brazil at the coordinates (23º46'16" S & 53º19'38" WO), and altitude of 442 m, the fruits of G. integrifolia were collected in May and the leaves and flowers in December 2017. The crude extracts of G. integrifolia leaves, flowers, and fruits were prepared by dynamic maceration technique. The chemical composition of the extracts was determined by gas chromatography coupled to a mass spectrometry. The insecticidal activity of the crude extracts of G. integrifolia were carried out on larvae and pupae of A. aegypti in concentrations between 0.001 to 25 000 mg/mL, and afterwards the lethal concentrations that kill 50 % (LC50) and 99.9 % (LC99.9) were determined by probit analysis. Anticholinesterase activity was determined by bioautographic method at concentrations from 0.000095 to 50 mg/mL. Results: The yield of G. integrifolia crude extracts were 8.2, 9.1, and 17.3 % for flowers, fruits, and leaves, respectively. The chemical composition of G. integrifolia extracts was characterized by presence of fatty acid esters, phytosterols, vitamins, oxygenated diterpenes and organosulfur compounds. The flower extract presented the high amount of sulfur compounds (20.2 %) such as disulfide, bis (2-sulfhydryl ethyl) (11.9 %), 2,3,5-trithiahexane (6.2 %), 1,2,4-trithiolane (1.1 %), and 2,4-dithiapentane (1.1 %). Regarding the insecticidal activity, flower extract showed highly active with LC99.9 of 0.032 mg/mL and LC99.9 of 0.969 mg/mL on A. aegypti larvae and pupae, respectively, and the highest inhibition of acetylcholinesterase enzyme (0.00019 mg/mL) ex situ. The flower extract presented anticholinesterase and larvicide activity, respectively, 12.8 % and 35.6 % greater than the control temephos. Conclusions: This study opens new perspectives on the use of extracts from G. integrifolia as a bioinsecticide alternative for the control of A. aegypti larvae and pupae.

Introducción: Los fitoinsecticidas son alternativas para el control de insectos en diferentes etapas, Gallesia integrifolia (Spreng.) Harms, familia Phytolacaceae, conocida popularmente como pau d'alho, árbol de ajo y guararema en Brasil, es conocida por su fuerte olor aliáceo debido a la presencia de moléculas de azufre en la planta. Esta especie presenta actividad biológica y potencial efecto insecticida que aún no está explotado. Objetivo: El objetivo de este estudio fue evaluar la actividad biológica del extracto crudo etanólico de las hojas, flores y frutos de G. integrifolia en el control de las larvas y pupas de la tercera etapa de Aedes aegypti. Métodos: El material botánico fue recolectado en la ciudad de Umuarama, Paraná, Brasil (23º46'16" S & 53º19'38" W), a una altitud de 442 m y los frutos de G. integrifolia fueron recolectados en mayo de 2017 y las hojas y flores en diciembre del mismo año. Los extractos crudos de hojas, flores y frutos de G. integrifolia se prepararon por técnica de maceración dinámica. La composición química de los extractos se determinó por cromatografía de gases acoplada a espectrometría de masas. La actividad insecticida de los extractos crudos de G. integrifolia fue evaluada en larvas y pupas de A. aegypti en concentraciones entre 0.001 a 25 000 mg/mL, y las concentraciones letales que matan 50 % (CL50) y 99.9 % (CL99.9) de larvas fueron determinados por análisis de probit. La actividad anticolinesterasa fue evaluada por método bioautográfico en concentraciones de 0.000095 a 50 mg/mL. Resultados: El rendimiento de los extractos crudos de G. integrifolia fue de 8.2, 9.1 y 17.3 % para flores, frutos y hojas, respectivamente. La composición química de los extractos de G. integrifolia se caracterizó por la presencia de ésteres de ácidos grasos, fitosteroles, vitaminas, diterpenos oxigenados y compuestos organosulfurados. El extracto de las flores presentó alta cantidad de compuestos de azufre (20.2 %) como disulfuro, bis(2-sulfhidril etilo) (11.9 %), 2,3,5-tritiahexano (6.2 %), 1,2,4-tritiolano (1.1 %) y 2,4-ditiapentano (1.1 %). En relación con la actividad insecticida, el extracto de las flores mostró una gran actividad con CL99.9 de 0.032 mg/mL y CL99.9 de 0.969 mg/mL en larvas y pupas de A. aegypti, respectivamente, y la inhibición más alta de la enzima acetilcolinesterasa (0.00019 mg/mL) ex situ. El extracto de las flores presentó actividad anticolinesterasa y larvicida, 12.8 y 35.6 %, respectivamente, mayor que el control temephos. Conclusiones: Este estudio abre nuevas perspectivas sobre el uso de extractos de G. integrifolia como alternativa bioinsecticida para el control de larvas y pupas de A. aegypti.

Antimicrobial activity of Asteraceae species against bacterial pathogens isolated from postmenopausal women.

PURPOSE: Investigation of the antibacterial action of aqueous extracts of Bidens sulphurea, Bidens pilosa, and Tanacetum vulgare, species of Asteraceae family that are popularly used for the treatment of genito-urinary infection. METHODS: The minimum inhibitory concentration (MIC) and minimal bacterial concentration (MBC) of the extracts against standard strains of Staphylococcus aureus (ATCC25923), Enterococcus faecalis (ATCC29212), Escherichia coli (ATCC25922), and Pseudomonas aeruginosa (ATCC27853) and against bacteria that were isolated from cultures of vaginal secretions and urine from menopausal women with a diagnosis of recurrent urinary tract infections (rUTI) were determined by broth microdilution. RESULTS: The MIC values of the three extracts against Gram-positive and Gram-negative standard bacterial strains ranged from 7.81 to 125.00 mg ml-1, and the MBC values ranged from 7.81 to 500.00 mg ml-1. However, B. sulphurea was more efficient. In the urine samples, the three extracts inhibited the growth of coagulase-negative Staphylococcus spp., and the B. pilosa was the most active extract against E. coli compared with the other ones. For the vaginal secretion samples, no significant differences in the inhibition of coagulase-positive Staphylococcus spp. and P. mirabilis were found among the extracts. T. vulgare and B. sulphurea were more effective in inhibiting coagulase-negative Staphylococcus spp. compared with B. pilosa. E. coli was more susceptible to the B. sulphurea extract compared with the B. pilosa and T. vulgare extracts. CONCLUSION: The present results suggested the potential medicinal use of Asteraceae species, especially B. sulphurea, as therapeutic agents against rUTI-related bacteria.