Active metabolites of the genus Piper against Aedes aegypti: natural alternative sources for dengue vector control / Metabolitos activos del género Piper contra Aedes aegypti: fuentes alternativas naturales para el control de vectores de dengue / Metabolitos secundarios do gènero Piper contra Aedes aegypti: fontes naturais alternativas para o controle do vector da dengue

The mosquito, Aedes aegypti, is the principal vector of the viruses responsible for dengue and dengue hemorrhagic fevers. The mosquito is widespread throughout tropical and sub-tropical regions; its prevalence makes dengue one of the most important mosquito-borne viral diseases in the world occurring annually in more than 100 endemic countries. Because blood is essential to their development cycle, the Aedes species maintains a close association with humans and their dwellings. Fittingly, the most widely adopted strategy to decrease the incidence of these diseases is the control of the mosquito larvae population. The emergence of insecticide-resistant mosquitoes has amplified the interest in finding natural products effective against Aedes aegypti adults, as well as larvae. Plant-derived compounds have played an important role in the discovery of new active entities for vector management as they are safer and have lower toxicity to humans in comparison to conventional insecticides. This review assesses a naturally occurring plant matrix and pure compounds of the Piper species, which have been shown to be active against Aedes aegypti.

El mosquito, Aedes aegypti, es el principal vector del dengue y de la fiebre hemorrágica. El mosquito está diseminado en regiones tropicales y subtropicales. La prevalencia del dengue lo hace una de las enfermedades virales, transmitidas por mosquitos, más importantes en el mundo, ocurriendo anualmente en más de 100 países endémicos. Dado que la sangre es esencial para su ciclo de desarrollo, la especie Aedes mantiene una estrecha relación con los seres humanos y sus viviendas. La estrategia más ampliamente adoptada para disminuir la incidencia de estas enfermedades es el control de las larvas de los mosquitos. La aparición de mosquitos resistentes a los insecticidas ha amplificado el interés en la búsqueda de productos naturales, eficaces contra Aedes aegypti adultos y larvas. Los compuestos derivados de plantas han jugado un papel importante en el descubrimiento de nuevas entidades activas para el control del vector; estos son más seguros y menos tóxicos para los seres humanos en comparación con los insecticidas convencionales. Esta reseña evalúa matrices vegetales de origen natural y compuestos puros de especies Pper, que han demostrado ser activos contra Aedes aegypti.

O mosquito Aedes aegypti é o principal vetor dos virus responsáveis pela dengue e pelas febres hemorrágicas de dengue. O mosquito está generalizado em todas as regioes tropicais e sub-tropicais; a sua prevaléncia torna a dengue uma das doencas virais mais importantes transmitidas por mosquitos no mundo que ocorrem anualmente em mais de 100 países endémicos. Como o sangue é essencial para o seu ciclo de desenvolvimiento, a espécie Aedes mantém uma estreita associacáo com os seres humanos e suas habitacoes. Apropriadamente, a estratégia mais adotada para diminuir a incidència dessas doencas é o controle da populacho de larvas de mosquito. O surgimento de mosquitos resistentes aos inseticidas tem ampliado o interesse em encontrar produtos naturais eficazes contra Aedes aegypti adultos, bem como larvas. Compostos derivados de plantas, tém desempenhado um papel importante na descoberta de novas entidades ativas para gestáo de vetores em que sao mais seguros e possuem baixa toxicidade para os seres humanos, em comparacáo com os insecticidas convencionais. Esta avaliacáo avalia a matriz de plantas que ocorrem naturalmente e compostos puros das espécies de Pifter, que tém se mostrado ativa contra Aedes aegypti.

Growth study and essential oil analysis of Piper aduncum from two sites of Cerrado biome of Minas Gerais State, Brazil

Piper aduncum L., Piperaceae, stands out due to its biological activities, however, it is still found in the wild and little is known about its agronomic point of view. The aim of this study was to evaluate the growth and to analyze the chemical composition of essential oils from leaves of P. aduncum collected in two different sites of Cerrado as well as in cultivated plants. The cultivation was installed out in a greenhouse using cuttings of adult specimens. Essential oils were obtained from fresh leaves. Plants from the two studied locations showed erect growth habit and behavior of linear growth. The essential oils composition of P. aduncum from Bocaiuva did not differ between wild and cultivated plants, as the major substance identified as 1,8-cineole. The plants from Montes Claros site showed a distinct concentration for the two samples, being the major substance characterized as transocimene (13.4%) for wild and 1,8-cineole (31.3%) for cultivated plants. Samples from both locations showed a similar essential oil composition in cultivars. Our results showed that P. aduncum cultivation is feasible and the variation in chemical composition of the two sites may indicate an environmental influence, since chemical and isoenzyme analysis did not show great differences.

Preliminary Anticancer Potency Evaluation and Phytochemical investigation of Methanol Extract of Piper claussenianum (Miq.) C. DC.

Bioassay guided isolation of active natural compounds was performed to investigate the anti-tumor potential of the crude extract and isolated compounds from inflorescences of Piper claussenianum. LC-DAD-UV, GC-MS and NMR analyzes revealed the presence of phenolic metabolites in the methanol crude extract. Phytochemical procedures lead to the isolation of the major flavonoids, 2’,6’-dihydroxy-4-methoxychalcone, 5,7- dihydroxyflavanone and 5-methoxy-7-hydroxyflavanone that were assayed for inhibition or viability stimulation of the human breast cancer cell line MCF-7. The results suggest the 2’,6’-dihydroxy-4-methoxychalcone as the biologically active compound in the crude methanol extract of inflorescences from P. claussenianum. The crude extract was found as potential natural source of compounds with breast cancer cell inhibition properties. All isolated compounds have not been described from this species yet.

Essential oil from leaves of Lantana camara: a potential source of medicine against leishmaniasis

Leishmaniasis is an infection of viscera or tegument caused by protozoa Leishmania sp. The extensive period required for the treatment, which involves the use of toxic medicines, leads patients to drop treatment increasing the development of resistant forms of Leishmania sp. Lantana camara L., Verbenaceae, is a tropical plant native from America. Folk uses have been described for treatment of tumors, tetanus, rheumatism and malaria. This study evaluates the leishmanicidal activity of the essential oil of leaves from L. camara on promastigote forms of Leishmania chagasi and L. amazonensis and its toxic effects on Artemia salina (brine shrimp test), macrophage cultures and BALB/c mice. The chemical composition was evaluated using the gas chromatography coupled with mass spectrometer (GC-MS). Thirty substances, mostly mono and sesquiterpenes were identified. The most representative constituents were: germacrene D (24.90%), farnesene derivatives (22%) and (E)-cariophylene (14.31%). Bioassays revealed a significant leishmanicidal activity of essential oil against L. amazonensis (IC50 0.25 µg/ mL) and a potential toxic effect on Brine shrimp (LC50 10 µg/mL) and macrophage assays (CC50 4 µg/mL), while there was no toxic manifestation on mice. The data show the relevant potential of L. camara as a source of medicine for leishmaniasis treatment.

Chemical composition fluctuations in roots of Plumbago scandens L. in relation to floral development

Plumbago scandens L. is a Brazilian tropical/subtropical species that occurs along the coast. Chemically it is mainly represented by naphthoquinones, flavonoids, terpenoids and steroids. The aim of the present work is to study quantitative changes in the root metabolic production of Plumbago scandens during different physiologic developmental stages relative to floration. The results indicated the presence of four substances in the extracts: plumbagin, epi-isoshinanolone, palmitic acid and sitosterol, independent on developmental stage. The naphthoquinone plumbagin has always showed to be the major component of all extracts. Naphthoquinones exhibited their highest content during floration, while the content of the two others components decreased during this stage, revealing an inverse profile. The chemical composition changed depending on the plant requirements.

Plumbago scandens L. é uma espécie brasileira tropical/subtropical que ocorre ao longo da costa. Quimicamente, é principalmente representada por naftoquinonas, flavonóides, terpenóides e esteróides. objetivo do presente trabalho é estudar mudanças quantitativas da produção metabólica nas raízes de Plumbago scandens durante diferentes estágios de desenvolvimento fisiológico, relativos à floração. Os resultados indicaram a presença de quatro substâncias nos extratos: plumbagina, epi-isoshinanolona, ácido palmítico e sitosterol, independente do estágio de desenvolvimento. A naftoquinona plumbagina tem sempre mostrado ser o componente majoritário de todos os extratos. Naftoquinonas exibiram seus maiores conteúdos durante a floração, enquanto o conteúdo dos dois outros componentes decresceu durante este estágio, revelando um perfil inverso. A composição química modificou dependendo das necessidades da planta.

Antileishmanial activity of nerolidol-rich essential oil from Piper claussenianum

Leishmaniasis is one of the most neglected tropical diseases, representing a group of parasitic diseases worldwide spread, occurring in 88 tropical and subtropical countries. Approximately 350 million people live in areas of active transmission of leishmaniasis, with about 1-2 million estimated new cases occurring every year. More than 90 percent of the cutaneous cases appear in developing countries. Efforts to improve the therapeutic arsenal against leishmaniasis have led to the search for new and cheap range of drugs. In this study, the nerolidol-rich essential oil from Piper claussenianum (Miq.) C. DC., Piperaceae, was assayed on arginase activity of Leishmania amazonensis. The effect of this essential oil on arginase activity levels showed an enzyme inhibition of 62.2 percent. This result stimulates the scientific interest about the potential value of this plant species on neglected diseases as potential new natural product source of pharmacological interest for the treatment of leishmaniasis.

Brazilian Bromeliaceae species: isolation of arylpropanoid acid derivatives and antiradical potential / Espécies de Bromeliaceae Brasileiras: isolamento de derivados arilpropanoídicos e potencial antiradicalar

A total of twenty different extracts from six Brazilian Bromeliaceae species was screened for antioxidant activity by assessment of their capacity to scavenge the DPPH radical. In a general way, the polar rhizome extracts from Bromeliaceae representatives showed better antioxidant results than the extracts from leaves and fruits of the same species. The best results were found for the rhizome extracts of Vriesea procera (Mart. ex Schult.f.) Wittm. and Neoregelia cruenta (Graham) L.B. Sm. Crude methanol extract of Ananas bracteatus (Lindl.) Schult. & Schult. f. leaf had a significant antiradical activity among the leaves extracts assessed its purification afforded four metabolites: 2-O-feruloyl glyceride, 2-O-p-coumaroyl glyceride, 5,7,4'-trihydroxy-3,3',5'-trimethoxyflavone and 3-O-β-D-glucopyranosyl sitosterol.

Um total de vinte extratos de seis espécies de Bromeliaceae brasileiras foram avaliadas quanto a atividade antioxidante, usando-se o método colorimétrico de redução do radical DPPH. De maneira geral, os extratos polares dos rizomas das espécies de Bromeliaceae testadas revelaram melhor perfil antioxidante do que os extratos das folhas e dos frutos das mesmas espécies. Os melhores resultados foram encontrados para os rizomas de Vriesea procera (Mart. ex Schult.f.) Wittm. e Neoregelia cruenta (Graham) L.B. Sm. O extrato bruto metanólico das folhas de Ananas bracteatus (Lindl.) Schult. & Schult. f. apresentou uma atividade significativa, em relação aos extratos de folhas testados, e o processo de purificação desse extrato resultou na identificação de quatro metabólitos: ferulato de 2-glicerila, p-cumarato de 2-glicerila, 5,7,4'-triidroxi-3,3',5'-trimetoxiflavona e 3-O-β-D-glicopiranosil sitosterol.

Essential oil from two populations of Echinodorus grandiflorus (Cham. & Schltdl.) Micheli (Chapéu de couro)

Analysis by Gas Chromatography and Gas Chromatography/Mass Spectrometry of the essential oils obtained from leaves of Echinodorus grandiflorus ("Chapéu de couro") from two different populations (Big Leaves and Small Leaves), collected monthly between September 1998 and December 1999 revealed 17 components. Phytol was the major constituent for both populations. The main sesquiterpene representatives are (E)-caryophyllene, alpha-humulene and (E)-nerolidol.

Análise por cromatografia com fase gasosa e cromatografia com fase gasosa acoplada à espectrometria de massas de óleos essenciais obtidos de folhas de Echinodorus grandiflorus ("Chapéu-de-couro") em duas diferentes populações (folhas grandes e folhas pequenas), coletadas mensalmente entre setembro de 1998 e dezembro de 1999, revelou 17 componentes. Fitol foi o constituinte majoritário em ambas populações. Os principais representantes sesquiterpênicos foram (E)-cariofileno, alfa-humuleno e (E)-nerolidol.

Effect of leaf essential oil from Piper solmsianum C.DC. in mice behaviour

The essential oil from Piper solmsianum leaves and its major compound (sarisan) were tested to verify their influences upon mice behaviour. The essential oil was obtained by hydrodistillation in a modified Clevenger extractor and analysed by GC/ MS. This analysis revealed in the oil the presence of monoterpenes, sesquiterpenes and of arylpropanoids. The compound sarisan, a myristicin analogue, was isolated from the oil to perform the pharmacological tests. Emulsions of the oil and of sarisan (5.0 and 10.0 percent v/v) were used in the tests. Pentobarbital (30 mg/ kg s.c.) or diazepam (2.5 mg/ kg s.c.) were tested as standard drugs to verify depressant or anxiolytic effects, respectively. Both essential oil and sarisan showed to have exciting and depressant effects in the tested animals

Potential sources of biodynamically active natural products in Brazil

In contrast to China where vegatation is predominantly herbaceous, vegetation in Brazil is commonly arboreous. This fact may explain why Chinese drugs are usually acetate derived, while actual and potential natural therapeutic agents from Brazil are mostly shikimate derived. Only relatively few compounds isolated from Brazilian plants have been submitted to adequate pharmacological testing .