RESUMO Introdução: as terapias alternativas utilizando plantas medicinais e fitoterápicos vêm crescendo em todo o mundo, pois os tratamentos naturais apresentam baixo custo e menor efeito tóxico em relação aos medicamentos convencionais disponí veis. Objetivo: avaliar a citotoxicidade in vitro e a genotoxicidade ex-vivo de espécies brasileiras da família Malvaceae: Waltheria viseosissima A. St. Hil. Métodos in vitro foram utilizados para verificar o potencial citotóxico por meio de ensaios hemolíticos e anti-hemolíticos e da análise genotóxica ex-vivo. Resultados: o extrato etanólico bruto (EEB) e a fração clorofórmica (FC) foram obtidos na amostra vegetal utilizada neste estudo; os produtos EEB-Wv e FC-Wv exibiram o menor potencial citotóxico com hemólise inferior a 40 % em todas as concentrações avaliadas. Foi descrito efeito anti-hemolítico moderado em todas as amostras tratadas com 500 e 1000 μg/mL, com hemólise < 60 %. Além disso, os compostos mostraram baixo efeito genotóxico ex-vivo com um índice geral de células normais superior a 84 % em todas as concentrações. Conclusão: os resultados sugerem um baixo perfil tóxico dos compostos obtidos em espécies da família Malvaceae, indicando limites seguros para o uso desses produtos naturais.

RESUMEN Introducción: las terapias alternativas que utilizan plantas medicinales y medicinas a base de hierbas han ido creciendo en todo el mundo, ya que los tratamientos natu rales tienen un bajo costo y un efecto menos tóxico en comparación con los medica mentos convencionales disponibles. Objetivo: evaluar la citotoxicidad in vitro y la genotoxicidad ex-vivo de especies brasileñas de la familia Malvaceae: Waltheria viseo-sissima A. St. Hil. Se utilizaron métodos in vitro para verificar el potencial citotóxico mediante ensayos hemolíticos y antihemolíticos y el análisis genotóxico ex-vivo. Resultados: el extracto de etanol crudo (EEC) y la fracción clorofórmica (FC) se obtuvieron en una muestra vegetal utilizada en este estudio; los productos EEC-Wv y FC-Wv exhibieron el potencial citotóxico más bajo con hemólisis menor al 40 % en todas las concentraciones evaluadas. Se describió un efecto antihemolítico mode rado en todas las muestras tratadas con 500 y 1000 μg/mL, con hemólisis <60 %. Además, los compuestos mostraron un bajo efecto genotóxico ex-vivo con un índice general de células normales superior al 84 % en todas las concentraciones. Conclu sión: los resultados sugieren un bajo perfil tóxico de los compuestos obtenidos de las especies de la familia Malvaceae, indicando límites de seguridad para el uso de estos productos naturales.

SUMMARY Introduction: Alternative therapies using medicinal plants and herbal medicines have been growing worldwide, as natural treatments have low cost and less toxic effect compared to conventional drugs available. Aim: To evaluate in vitro cytotox icity and ex-vivo genotoxicity of Brazilian species of the Malvaceae family: Waltheria viseosissima A. St. Hil. In vitro methods were used to verify the cytotoxic poten tial through hemolytic and antihemolytic assays and the ex-vivo genotoxic analysis. Results: The Crude Etanolic Extract (CEE) and Cloroformic Fraction (CF) was obtained in vegetal sample used on this study; the CEE-Wv and CF-Wv prod ucts exhibited the lowest cytotoxic potential with hemolysis less than 40% in all concentrations evaluated. A moderate anti-hemolytic effect was described in all samples treated with 500 and 1000 μg/mL, with hemolysis <60 %. In addition, the compounds showed low ex-vivo genotoxic effect with a general index of normal cells greater than 84 % at all concentrations. Conclusion: The results suggest a low toxic profile of the compounds obtained from species of the Malvaceae family, indicating safe limits for the use of these natural products.

Abstract The species Waltheria viscosissima A.St.–Hil, Malvaceae, which is known as ‘malva-branca', is traditionally used in the Brazilian northeast for the treatment of coughs. This research looks towards reporting the isolation of phytoconstituents of W. viscosissima, as well as the quantification of its phenolics, total flavonoid content, and free radical scavenging potential, along with an evaluation of its larvicidal activity against Aedes aegypti larvae. Chromatographic techniques were used to isolate the compounds and a structural elucidation was performed by 1D and 2D NMR. The quantification of total phenolics and flavonoids and the DPPH˙ radical scavenging activity was determined through spectrophotometric methods. Consequently, the phytochemical investigation led to the identification of fourteen compounds from the aerial parts of the W. viscosissima: steroids, triterpenes, alkaloids, and eight flavonoids previously reported in the literature. The quantification of compounds showed that the aerial parts extract possessed high concentration of flavonoids, while the roots extract were rich in other phenolic compounds. At the DPPH˙ free radical scavenging assay, the roots extract presented EC50 = 77.32 ± 4.37 µg/ml and the aerial parts extracts showed EC50 = 118.10 ± 1.21 µg/ml. W. viscosissima roots extract showed the most potent larvicidal activity against Ae. aegypti (LC50 = 4.78 mg/ml), with the potential of being used in effective and economically viable preparations that can be catered for domestic use towards controlling the vector insect of severe diseases, such as dengue and Zika.

ABSTRACT Pilosocereus pachycladus F. Ritter, Cactaceae, popularly known as "facheiro", is used as food and traditional medicine in Brazilian caatinga ecoregion. The plant is used to treat prostate inflammation and urinary infection. The present work reports the first secondary metabolites isolated from P. pachycladus. Therefore, the isolated compound 4-hydroxy-3,5-dimethoxy benzaldehyde (syringaldehyde) was evaluated as modulator of Staphylococcus aureus pump efflux-mediated antibiotic resistance. The isolation of compounds was performed using chromatographic techniques and the structural elucidation was carried out by spectroscopic methods. In order to evaluate syringaldehyde ability to modulate S. aureus antibiotic resistance, its minimum inhibitory concentrations (µg/ml) was first determinate, then, the tested antibiotics minimum inhibitory concentrations were determined in the presence of the syringaldehyde in a sub-inhibitory concentration. The chromatographic procedures led to isolation of twelve compounds from P. pachycladus including fatty acids, steroids, chlorophyll derivatives, phenolics and a lignan. The syringaldehyde did not show any antibacterial activity at 256 µg/ml against S. aureus. On the other hand the compound was able to reduce the antibiotic concentration (tetracycline, norfloxacin, ethidium bromide) required to inhibit the growth of drug-resistant bacteria, showing the ability of syringaldehyde of inhibiting the efflux pump on these bacteria.