RESUMO
Luteolin (LUT) is a flavonoid found in several edible and medicinal plants. It is recognized for its biological activities such as antioxidant, anti-inflammatory, neuroprotective, and antitumor effects. However, the limited water solubility of LUT leads to poor absorption after oral administration. Nanoencapsulation may improve the solubility of LUT. Nanoemulsions (NE) were selected for the encapsulation of LUT due to their biodegradability, stability, and ability to control drug release. In this work, chitosan (Ch)-based NE was developed to encapsulate luteolin (NECh-LUT). A 23 factorial design was built to obtain a formulation with optimized amounts of oil, water, and surfactants. NECh-LUT showed a mean diameter of 67.5 nm, polydispersity index 0.174, zeta potential of +12.8 mV, and encapsulation efficiency of 85.49%. Transmission electron microscopy revealed spherical shape and rheological analysis verified the Newtonian behavior of NECh-LUT. SAXS technique confirmed the bimodal characteristic of NECh-LUT, while stability analysis confirmed NECh-LUT stability when stored at room temperature for up to 30 days. Finally, in vitro release studies showed LUT controlled release up to 72 h, indicating the promising potential of NECh-LUT to be used as novel therapeutic option to treat several disorders.
RESUMO
The aim of this research was to evaluate the fractions obtained from the leaf, stem and roots of Allamanda schottii Pohl, Apocynaceae, responsible for the cytotoxicity, using several cell lines. Cytotoxicity was correlated with the season the part of the plant, and the major compounds were assessed. The ethanol extracts of leaves, stems and roots obtained at different seasons were evaluated in the human erythromyeloblastoid leukemia cell line (K562). Subsequently the ethanol extracts and dichloromethane fractions collected in winter were evaluated in mouse fibroblast cell line (Mus musculus) (L929), cervix adenocarcinoma (HeLa), human pre-B leukemia (Nalm6), as well as K562 cell line. The compounds plumericin, plumieride and ursolic acid isolated from ethanol extracts of the stems were evaluated in the same cell lines, as well as on breast adenocarcinoma cell line (MCF-7), and Mus musculus skin melanoma cell line (B16F10). The chromatographic profiles of the dichloromethane fractions were obtained by high performance liquid chromatography. The results revealed that the season during which A. schottii was collected, and the part of the plant analyzed, influence the cytotoxicity on the K562 cells tested. On the other hand the dichloromethane fractions, mainly from the stems and roots, are responsible for the cytoxicity on the cells tested. These results may be associated with the seasonal variation of plumericin in these parts of the plant. This information is in accordance with the HPLC analysis. The results clearly show the potential for the phytotherapeutic use of this species, and suggest that the cytotoxic activity observed may be due to the presence of plumericin, or to minor compounds not yet identified. The seasonal influence on the production of secondary metabolites was verified.
RESUMO
Bromelia antiacantha (known as wild banana) is traditionally used to treat coughs, as an emollient and antitussive, and to treat mouth and skin ulcers. To investigate the radical scavenger properties, DPPH and phosphomolybdenium were used, with low antioxidant activity being observed for both (below 5 mg/ml of extract presented no activity for both techniques). An HPLC fingerprint of phenolic compounds was developed and total phenolics through Folin-Ciocalteau method was an average of 500 µg/g of fresh fruits. Any cytotoxicity was observed on L929 fibroblasts cells for aqueous, methanol and lipid extracts between 500 and 0.01 µg/ ml. The wild banana extract (1000 µg/mL) shown a lower genotoxicity when compared to the negative and positive (MMS) controls. Abundant calcium oxalate crystals and sucrose were found and characterized through NMR and X-ray diffraction respectively. Its centesimal composition indicated abundant carbohydrates (45 percent) and lipids (18 percent). The carbohydrate analysis showed acidic monosaccharides, and the lipid analysis shown palmitic and linoleic acids in similar quantities (30 percent each) and oleic acid 20 percent, among others, through GC-FID. The viscosity of the water-soluble polysaccharide sub-fraction (5 g/L) was similar to that of water.
O chá dos frutos maduros de Bromelia antiacantha (banana-de-bugre; banana-do-mato) é usado tradicionalmente para tratar desordens respiratórias, como antitussígeno e também para tratar ulceras de pele e boca. Neste trabalho pesquisou-se o potencial de captação de radicais livres do extrato aquoso e extrato metanólico através da reação de redução do DPPH e do fosfomolibdenio, sendo encontrada baixa atividade nos dois modelos (abaixo de 5 mg/ml nenhuma atividade foi detectada em ambos extratos). Os compostos fenólicos totais foram determinados através de Folin-Ciocalteau, sendo encontrados 500 µg/g de fruto maduro fresco, e foi desenvolvido fingerprint dos compostos fenólicos através de CLAE-DAD. Nenhuma citotoxicidade foi observada em fibroblastos L929 para extratos aquoso, metanólico e lipídico entre 500 e 0,01 µg/ml, assim como baixa genotoxicidade (1000 µg/mL) quando comparados aos controles negativo e positivo (MMS). Abundantes cristais de oxalato de cálcio e de sacarose foram observados e caracterizados por RMN e difração de Raios-X respectivamente, e a composição centesimal do fruto indicou abundantes carboidratos (45 por cento) e lipídeos (18 por cento). A analise de carboidratos encontrou componentes monosacarídicos ácidos e foram encontrados acido palmítico e linoléico em quantidades similares (30 por cento cada) e 20 por cento de acido oléico, entre outros ácidos graxos através de CG-DIC. A viscosidade da sub-fração polissacarídica solúvel em água (5 g/L) foi semelhante a da água.