Momordica charantia L. extracts against Aedes aegypti larvae / Extratos de Momordica charantia L. sobre larvas de Aedes aegypti

Mormodica charantia (Curcubitaceae) is a plant with great medicinal potential, also used as an alternative of mosquitoes control as demonstrated by previous studies. We evaluated the larvicidal activity of crude extracts of ethyl acetate, methanol and hexane from flowers and fruits of M. charantia against Aedes aegypti (Culicidae). Flowers and fruits were macerated in methanol, ethyl acetate and hexane. Bioassays were performed with application of the extracts at final concentrations of 1 - 200 µg/mL in the middle of the third instar larvae of A. aegypti (L3). The results showed high toxicity to ethyl acetate extracts from flowers and fruits at concentrations of 200 µg/mL and 100 µg/mL, with 97% and 87% of larvae mortality (L3), respectively. Hexane extract demonstrated low toxicity, while methanol extract exhibited 78% larval mortality. The data suggested that the ethyl acetate extracts of flowers and fruits of M. charantia can effectively contribute to larvicidal activity. In addition, purification of M. charantia extracts may lead to a promising larvicidal activity to control the A. aegypti population.

Mormodica charantia (Curcubitaceae) é uma planta com grande potencial medicinal, sendo também uma alternativa no controle de mosquitos conforme demonstrado por estudos prévios. Avaliou-se a atividade larvicida dos extratos brutos de acetato de etila, metanólico e hexânico das folhas, flores e frutos de M. charantia no Aedes aegypti (Culicidae). Folhas, flores e frutos foram macerados em metanol, acetato de etila e hexano. Os bioensaios foram realizados com aplicação dos extratos nas concentrações finais de 1-200 µg/mL no meio de criação das larvas de terceiro estádio de A. aegypti (L3). Os resultados obtidos apontaram alta toxicidade para os extratos de acetato de etila das flores e frutos nas concentrações de 200 µg/mL e 100 µg/mL com mortalidade em L3 de 96,7% e 87%, respectivamente. Baixa toxicidade para o extrato hexânico e o extrato metanólico apresentou mortalidade de 78% larval. Os dados sugerem que os extratos de acetato de etila das flores e frutos de M. charantia podem contribuir efetivamente para atividade larvicida no controle da população de A. aegypti.

Larvicide potential of genus CrotonL. (Euphorbiaceae)inbiological control of Aedes aegyptiL. (Diptera: Culicidae)

The reemerging diseases caused by Aedes aegyptiare one of the main public health problems in the world. The control of mosquitoes using larvicidal compounds from products of plant origin is anexcellent alternative. This study aims to evaluate the larvicidal potential of fractions in hexane, chloroform, ethyl acetate and hydromethanol from the ethanolicleaf extract of two species of the genus CrotonL. (Euphorbiaceae) against larval forms of A. aegypti, as an alternative tool to control this vector. Dry leaves of Croton betaceusBaill. and Croton lundianus(Didr.) Müll.Arg. were used for biological tests. The compounds were extracted with ethanol (99.8%). The ethanolic extracts of the leaves were suspended in a methanol / water solution and were successively subjected to the liquid-liquid division process with solvents of different polarities: hexane, chloroform and ethyl acetate, giving rise to the four fractions. Larvicidal tests were performed with the ethanol extract and fractions resulting from the partition. In the study, the crude extract and the fractions showed larvicidal potential, being hexane fractionthe one with greatest activity.Mortality in C. betaceusfractions was up to 40%. Croton lundianuspresented mortality of up to 93.33% of the larvaesubmitted to the test. Data analysis showed larvicidal activity in the crude extract and fractions. The hexane fraction was more effective, especially in C. lundianus.

Tamizaje fitoquímico de Cassia uniflora Mill / Phytochemical screening of Cassia uniflora Mill

Introducción: Cassia uniflora Mill se emplea en el control aleloquímico de Parthenium hysterophorus; se ha reportado que presenta actividad larvicida frente a Aedes aegypti. Tradicionalmente se ha usado como antiespasmódico y para el tratamiento de erupciones cutáneas. Objetivo: realizar un tamizaje fitoquímico a los extractos etéreo, alcohólico y acuoso de la especie Cassia uniflora Mill para conocer los metabolitos secundarios que sean de interés biológico en la terapéutica. Métodos: se recolectaron partes aéreas y subterráneas de la planta, se lavaron, desinfectaron, secaron, pulverizaron y se sometieron a extracciones sucesivas con solventes de polaridad creciente. Los extractos se filtraron y se realizaron ensayos fitoquímicos de identificación. Resultados: el tamizaje fitoquímico, efectuado a los extractos etéreo, alcohólico y acuoso de las hojas, tallos, cáscaras de los frutos, semillas y raíces, demostró la existencia de varias familias de metabolitos secundarios de interés biológico y farmacológico, entre los que se destacan, por su significativa presencia, las quinonas y las coumarinas. Conclusiones: de acuerdo con la diversidad de metabolitos secundarios presentes en las partes evaluadas de C. uniflora, así como los efectos biológicos reportados para la especie, sería interesante realizar nuevos estudios que aporten evidencias sobre su eficacia y seguridad, como forma de avalar su empleo tradicional.

Introduction: Cassia uniflora Mill is used for the allelochemical control of Parthenium hysterophorus; and its larvicidal activity on Aedes aegypti has been reported. It has also been applied as antispasmodic agent and as treatment of cutaneous rash. Objective: to perform a phytochemical screening on alcoholic, ethereal and aqueous extracts from the Cassia uniflora Mill species to identify the secondary metabolites of biological interest in therapeutics. Methods: aerial and underground parts of the plant were harvested, washed, disinfected, dried, powdered and subjected to successive extractions with solvents of increasing polarity. The extracts were filtered to carry out phytochemical tests for identification. Results: the phytochemical screening of ethereal, alcoholic and aqueous extracts from leaves, stems, fruit peels, seeds and roots, confirmed the existence of several families of secondary metabolites of biological and pharmacological interest such as quinones and coumarins that stand out because of their significance presence. Conclusions: according to the diversity of secondary metabolites in the tested parts of Cassia uniflora Mill, as well as the biological effects reported for this species, it would be interesting to conduct new studies to find pieces of evidence on its effectiveness and safety, as a way of supporting traditional use of this plant.