Toxicity of vegetable oils to the coconut mite Aceria guerreronis and selectivity against the predator Neoseiulus baraki.

The coconut mite, Aceria guerreronis (Acari: Eriophyidae), is a major tropical pest of coconut. Here, we assessed the chemical profiles and the potential use of babassu, degummed soybean, and coconut oils to control A. guerreronis as well as their side-effects on the predatory mite Neoseiulus baraki (Acari: Phytoseiidae), a key natural enemy of the coconut mite. Babassu and coconut oils had similar fatty acids chemical profiles. All vegetable oils showed toxicity to A. guerreronis; degummed soybean oil exhibited the highest toxicity (LC50 = 0.15 µL/cm2). Although all oils were less toxic to N. baraki, their potential to attract/repel this predatory mite differed. Whereas N. baraki females were unresponsive to coconut oil at both concentrations (i.e., LC50 and LC99 estimated for A. guerreronis), irrespective of exposure period (i.e., 1 or 24 h), the babassu oil repelled the predator, independent of exposure period, when applied at its LC99 (1.48 µL/cm2). Intriguingly, this oil also exhibited attractiveness to N. baraki 24 h after exposure when applied at its LC50 (0.26 µL/cm2). A similar attractiveness pattern was recorded 24 h after N. baraki was exposed to degummed soybean oil at both concentrations tested (LC50 = 0.15 µL/cm2; LC99 = 1.39 µL/cm2). However, N. baraki was repelled by degummed soybean oil at its LC50 after 1 h of exposure. Therefore, the present study demonstrated that all the vegetable oils used here had higher toxicity to the coconut mite and considerable selectivity to the predator N. baraki, indicating they are promising tools that can potentially be included in management programs to control A. guerreronis in commercial coconut plantations.

Atividade farmacológica da monocrotalina isolada de plantas do gênero Crotalaria / Pharmacological activity of monocrotalina isolated from plants of the genus Crotalaria

Crotalaria retusa é uma planta encontrada no Nordeste brasileiro, pertence ao gênero Crotalaria e à família Leguminosae, e possuem mais de seissentas espécies no mundo e mais de quarenta no Brasil. As variedades tóxicas mais conhecidas são C. spectabilis, C. crispata, C. retusa, C. dura e C. globifera. Plantas do gênero Crotalaria são de interesse porque são usadas na medicina popular. Esses gêneros são ricos em alcaloides pirrolizidínicos (AP), que são as principais toxinas e apresentam efeitos pneumotóxicos, nefrotóxicos, cardiotóxicos, fetotóxicos, carcinogênicos, inflamação, hemorragia e fibrose. A monocrotalina é o principal alcaloide pirrolizidínico encontrado nessas plantas e é ativamente oxidada in vivo pelo citocromo P450 no fígado, formando intermediários altamente reativos tipo pirrólicos que são responsáveis pela ligação cruzada do DNA-DNA e DNA-proteína. O presente trabalho teve como objetivo fazer um levantamento bibliográfico via internet, utilizando bancos de dados, programas de pesquisa científica e pesquisa em livros relacionados, acerca da atividade farmacológica e do mecanismo de ação da monocrotalina extraída de plantas do gênero Crotalaria, ressaltando desde os aspectos botânicos da planta, estrutura química dos alcaloides pirrolizidínicos, exemplos experimentais de toxicidade e provável mecanismo de ação.

Crotalia retusa is a plant found in Brazilian Northeast and belongs to the genus Crotalaria and the family Leguminosae, which comprises more than 600 species throughout the world and more than forty in Brazil. The most known toxic species are C. spectabilis, C. crispata, C. retusa, C. dura and C. globifera. Plants of the Crotalaria genus are of great interest because they are used by humans for folk medicine. These plants are rich in pyrrolizidine alkaloids (PA), which are the main toxins that cause effects such as pneumotoxic, nefrotoxic, cardiotoxic, fetotoxic, carcinogenic, inflammation, hemorrhage and fibrosis. Monocrotaline is the main pirrolizidinic alkaloid found in plants and is actively oxidated in vivo by the cytochrome P450 in the liver, yielding highly reactive pyrrolic type intermediates, which are responsible for DNA-DNA and DNA-protein cross-links reaction. The aim of this work is to make a bibliographic survey via internet, using databases, scientific research programs and related books, about pharmacological activity and mechanism of action of monocrotaline extracted from plants of Crotalaria genus, emphasizing plant botanical aspects, chemical structure of pirrolizidinic alkaloid, experimental examples of toxicity and probable action mechanism.

A chemical marker proposal for the Lantana genus: composition of the essential oils from the leaves of Lantana radula and L. canescens.

Essential oil extracts from the leaves of two Lantana species (L. radula Sw. and L. canescens Kunth), for which no prior analysis has been reported, were analyzed by GC-MS. This information was utilized to propose chemical markers for Lantana species so that identification between physically similar plant species can be achieved through chemical analysis. Results showed 33 constituents for L. canescens, among which beta-caryophyllene (43.9%), beta-cubebene (10.1%), elixene (8.6%), beta-phellandrene (6.1%), alpha-caryophyllene (2.6%) and dehydro-aromadendrene (2.6%) were the principle components. L. radula revealed the presence of 21 compounds, the most abundant of which were beta-cubebene (31.0%), beta-caryophyllene (20.8%), elixene (10.0%), alpha-salinene (6.4%), beta-phellandrene (6.1%), copaene (4.9%) cadinene (1.4%) and psi-limonene (1.4%). The high concentration of beta-caryophyllene in the samples tested here and those in the literature make it a good candidate for a chemical marker for Lantana species, with beta-cubebene, elixene and beta-phellandrene following as minor compounds identified more sporadically in this genus. On the other hand, Lippia species, which are morphologically similar to those from the Lantana genus, would contain limonene, citral, carvacrol, beta-myrcene, camphor and thymol as the main chemical markers. These chemical markers would be a powerful tool for maintaining quality control in the extraction of essential oils for use in medicinal applications, as well as in identification of plant specimens to a taxonomist.

Phenylethanoid and lignan glycosides from polar extracts of Lantana, a genus of verbenaceous plants widely used in traditional herbal therapies.

Many references to the use of Lantana spp. can be found in the ethnopharmacological literature from locations around the globe. This study was focused on examining constituents from the polar extracts of Lantana radula Sw. and Lantana canescens Kunth, for which no prior chemical investigations had been reported. A new phenylethanoid glycoside, raduloside, and lignan glycoside, radulignan, were identified along with the known compounds alyssonoside, arenarioside, calceolarioside E, isonuomioside, samioside, and verbascoside.

Acanthospermum hispidum DC (Asteraceae): perspectives for a phytotherapeutic product: [revision] / Acanthospermum hispidum DC (Asteraceae): perspectivas para um produto fitoterápico: [revisão]

The "Espinho-de-cigano" plant (Acanthospermum hispidum DC) is used throughout northeastern (NE) Brazil as a folk medicine for asthma. Although little is actually known about the effectiveness and safety of this plant extract product, it is possible to find numerous medicines prepared from it in public health services or in stores selling natural products. This study aimed to undertake a literature review relative to Acanthospermum hispidum covering the period between 1926-2006 within the areas of ethnobotany, phytochemistry and pharmacology. The objective was to contribute to a better knowledge of this species and its uses, as well as to aid in improving its performance as a natural medicine. The species is easily identifiable and grows abundantly during the rainy seasons in NE Brazil; is amenable to cultivation without lose of its phytochemical profile, and toxicological studies have showed its safety as a medicine (although more studies will be required in that direction). As such, the compilation of the accumulated knowledge concerning this species will aid in evaluating its pharmacological value, guaranteeing quality control of the final product, and in preparing recommendations for usages and dosages that offer both safety and efficiency to the user.

A planta "Espinho-de-cigano" (Acanthospermum hispidum DC) é amplamente usada no nordeste do Brasil como medicamento popular para a asma. Embora muito pouco seja conhecido atualmente sobre a eficácia e segurança deste extrato vegetal, é possível encontrar numerosos medicamentos preparados com ele nos serviços públicos ou em lojas que vendem produtos naturais. Este estudo visa proceder a uma revisão de literatura relativa à A. hispidum, no período entre 1926-2006, nas áreas de etnobotânica, fitoquímica e farmacologia. O objetivo foi contribuir para um melhor conhecimento desta espécie e seus usos, assim como auxiliar na melhora de seu desempenho como um medicamento natural. A espécie é facilmente identificável e cresce abundantemente durante a estação chuvosa no nordeste do Brasil; é possível cultivá-la sem perda de seu perfil fitoquímico e os estudos toxicológicos têm mostrado sua segurança como um medicamento (embora mais estudos sejam requeridos nestes aspectos). Assim sendo, a compilação do conhecimento acumulado relativo a esta espécie auxiliará na avaliação de seu valor farmacológico, garantindo o controle de qualidade do produto final, e no preparo das recomendações para usos e dosagens que ofereçam segurança e eficiência ao usuário.

Antimicrobial activity and phytochemical profile from the roots of Lippia alba (Mill.) N.E. Brown

Lippia alba (Mill.) N.E. Brown (Verbenaceae) is commonly used in the Brazilian folk medicine to the treatment of gastric illnesses, diarrhea, fever, asthma, and as a tranquilizer. This work evaluated the antimicrobial activity of ethyl acetate, methanol and aqueous extracts from the roots of the L. alba using plates-holes diffusion assay and the phytochemical profile. The results obtained showed that the ethyl acetate and methanol extracts presented antimicrobial activity against Staphylococcus aureus (ATCC 6538P), Staphylococcus aureus (ATCC 6538) and Klebsiella pneumonia (ATCC 10031). Terpenoids, phenylpropanoids and sugars were detected in the phytochemical analysis.

Lippia alba (Mill.) N.E. Brown (Verbenaceae) é geralmente usada na medicina popular brasileira para o tratamento de doenças gástricas, febre, asma e como tranqüilizante. Este trabalho avaliou a atividade antimicrobiana dos extratos acetato de etila, metanol e aquoso das raízes de L. alba usando métodos de difusão em poços e o perfil fitoquímico. Os resultados obtidos mostraram que os extratos acetato de etila e metanol apresentaram atividade antimicrobiana contra Staphylococcus aureus (ATCC 6538P), Staphylococcus aureus (ATCC 6538) e Klebsiella pneumonia (ATCC 10031). Terpenóides, fenilpropanóides e açúcares foram detectados na análise fitoquímica.