RESUMO
Plant-derived molluscicides have been indicated as biodegradable and low-cost strategies for control of Biomphalaria spp., intermediate host for the Schistosoma. This study evaluated whether the crude ethanolic extract of the Persea americana stem bark has molluscicidal activity against embryos, newly-hatched and adults of Biomphalaria glabrata. The extract was obtained, characterized and its toxicity analyzed by snail embryotoxicity test (144 h) and acute toxicity test with newly-hatching and adult snails (96 h). Results showed the presence of flavonoids, anthraquinone heterosides, coumarins and tannins in the crude ethanolic extract, which showed molluscicidal activity against all life cycle stages of B. glabrata. The LC50 for embryos, newly-hatched and adults were 27.06, 30.60 and 55.55 ppm, respectively. Embryos exposed to the extract at 50 ppm showed hatching inhibition and at 6.2 and 25 ppm had the highest rates of morphological alterations, such as shell malformations and coagulation of the perivitelline substance. Adult snails exposed to the extract at 75 ppm showed a peak of behavioral changes, such as lethargy and shell reclusion, in addition to answers like hemolymph release in most concentrations. Further studies are required, prioritizing toxicity testing on non-target organisms and further elucidation of the active molecules.
Assuntos
Biomphalaria , Lauraceae , Moluscocidas , Persea , Animais , Moluscocidas/toxicidade , Casca de Planta , Extratos Vegetais/farmacologia , CaramujosRESUMO
ABSTRACT Dysphania ambrosioides (L.) Mosyakin and Clemants (Syn: Chenopodium ambrosioides L.), Amaranthaceae, is a plant with antibacterial, antifungal, antioxidant, antiparasitic and antitumor properties that is commonly used in Brazilian folk medicine. In this work we performed the optimization of ultrasound-assisted extraction of flavonoids in the aerial parts of D. ambrosioides. The flavonoid concentrations, as rutin equivalents, were quantified with the aid of a validated spectrophotometric method. The Box-Behnken (33) design with response surface methodology, for the independent variables, extraction time, temperature, and ethanol content, were used for the optimization of ultrasound-assisted extraction. The analytical method was selective, linear, without matrix interference, accurate, precise and robust. The best conditions for the ultrasound-assisted extraction of flavonoids were: time of 60 min, temperature of 57 °C and ethanol content of 57% (w/w). The methods of extracting and quantifying flavonoids developed in the present study have provided be eco-friendly, simple, and useful to determine the flavonoid content, expressed as rutin equivalents, in the aerial parts of D. ambrosioides.
RESUMO
Pterodon emarginatus Vogel, Fabaceae, is a tree species commonly known as "sucupira-branca". It is a popular medicinal plant in the Brazilian cerrado (Savanna). This study investigates the chemical variability of the essential oils from fruits of P. emarginatus. The fruits were collected from five sites in the Brazilian Cerrado and their essential oils were analyzed by GC/MS. The results obtained by Principal Component and Cluster Analysis identified two groups: cluster I containing β-caryophyllene and δ-elemene and cluster II containing α-copaene, β-cubebene, allo-aromadendrene, α-cubebene and γ-muurulene. The Canonical Discriminant Analysis was used to differentiate between clusters on the basis of essential oil composition. The results showed high variability in the composition of the essential oils from fruits of P. emarginatus, contributing to studies of domestication of this species.
RESUMO
As sementes de guaraná (Paullinia cupana Kunth, Sapindaceae) são utilizadas como estimulante e os principais constituintes químicos são as metilxantinas e os taninos, tais como catequina e epicatequina. Este trabalho teve por objetivo investigar um método por cromatografia líquida de alta eficiência (CLAE) para quantificar, simultaneamente, cafeína, teofilina, teobromina, catequina e epicatequina em pó de guaraná. Os valores obtidos foram comparados com os resultados encontrados no método espectrofotométrico da Farmacopéia Brasileira IV ed. Pelo método cromatográfico, os teores de metilxantinas e taninos totais foram de 4,04 por cento e 1,48 por cento, respectivamente. Os teores de metilxantinas e taninos totais, obtidos pelo método espectrofotométrico, foram de 4,88 por cento e 4,05 por cento, respectivamente. Acredita-se que, nas condições experimentais empregadas, o método espectrofotométrico não foi específico, quantificando outras substâncias fenólicas presentes no guaraná. Portanto, sugere-se o emprego desse método cromatográfico no controle de qualidade do guaraná em pó, por ser preciso, sensível, específico e rápido.
The seeds of Paullinia cupana Kunth, Sapindaceae, are used as a stimulant and the main chemical constituents are the methylxanthines and tannins, as catechin and epicatechin. This study aimed to investigate a method by high performance liquid chromatography (HPLC) to quantify both caffeine, theophylline, theobromine, catechin and epicatechin in powdered of P. cupana. The values obtained were compared with the results of the spectrophotometric method of the Brazilian Pharmacopoeia IV ed. For the chromatographic method, the levels of methylxanthines and total tannins were 4.04 percent and 1.48 percent, respectively. The levels of methylxanthines and total tannins obtained by the spectrophotometric method, were 4.88 percent and 4.05 percent, respectively. It is believed that, under our experimental conditions, the spectrophotometric method was not specific and quantified others phenolic substances present in the P. cupana. Therefore we suggest the use of this chromatographic method in quality control of P. cupana powder, to be accurate, sensitive, specific and fast.
