RESUMO

Ultrasonic-assisted extraction combined with statistical tools (factorial design, response surface methodology and kinetics) were used to evaluate the effects of the experimental conditions of temperature, solid-to-solvent ratio, ethanol concentration and time for the extraction of the total phenolic content from pecan nut shells. The optimal conditions for the aqueous and hydroalcoholic extract (with 20% v/v of ethanol) were 60 and 80 °C; solid to solvent ratio of 30 mL·g-1 (for both) and extraction time of 35 and 25 min, respectively. Using these optimize extraction conditions, 426 and 582 mg GAE·g-1 of phenolic compounds, from the aqueous and hydroalcoholic phases respectively, were obtained. In addition, the analysis of the phenolic compounds using the LC-ESI-MS/MS system allowed the identification of 29 phenolic compounds, 24 of which had not been reported in literature for this raw material yet.

Assuntos

RESUMO

O Acidente Vascular Encefálico (AVE) é definido como um quadro clínico de déficit neurológico que pode perdurar ou exceder as primeiras vinte e quatro horas do evento. A Organização Mundial de Saúde (OMS) revela que entre os anos de 2000 e 2011, o AVE apresentou-se como a segunda principal causa de óbitos em todo o mundo. Segundo o Ministério da Saúde, o AVE é a principal causa de morte no Brasil. É causado pela diminuição da perfusão sanguínea com depleção de oxigênio e glicose ao cérebro, causando redução dos níveis de ATP e predispondo a eventos como: excitotoxicidade glutamatérgica, influxo exacerbado de Ca++, estresse oxidativo, inflamação e apoptose, resultando em morte neuronal. O eriodictiol (3‟,4‟,5,7-tetrahidroxiflavanona) é um flavonóide encontrado na erva chinesa (Dracocephalum rupestre). Possui atividades anti-inflamatória, antioxidante e antiapoptótica já reportadas. O objetivo deste trabalho foi estudar os efeitos do eriodictiol sobre o dano neuronal, déficits de memória e resposta infamatória de camundongos submetidos à isquemia cerebral focal por oclusão permanente da artéria cerebral média (pMCAO). Os animais foram tratados oralmente com eriodictiol (1, 2 e 4 mg / kg) ou veículo (5% Tween 80 em salina 0,9%) 30 min antes, 2 horas depois da pMCAO e diariamente durante 4 dias. A pMCAO promoveu dano cerebral nos animais isquemiados, sendo esse comprovado, por meio da detecção do aumento significativo nas percentagens das áreas de infarto, pelos déficits sensório-motores observados e pela perda da viabilidade neuronal. O eriodictiol reduziu a área de infarto cerebral nas doses de 1, 2 e 4 mg/kg e preveniu os animais isquemiados dos déficits neurológicos 24h após pMCAO...

Stroke is defined as a clinical neurological deficit that may last or exceed the first twenty-four hours of the event. The World Health Organization (WHO) reveals that between 2000 and 2011, the Stroke was presented as the second leading cause of death worldwide. According to the Ministry of Health, stroke is the leading cause of death in Brazil. It is caused by decreased blood perfusion depleted of oxygen and glucose to the brain,causing ATP reduction levels and predisposing to events such as glutamatergic excitotoxicity, exacerbated influx of Ca++, oxidative stress, inflammation and apoptosis, resulting in neuronal death. The eriodictyol (3 ', 4', 5,7-tetrahydroxyflavanone) is a flavonoid found in the Chinese herb (Dracocephalum rupestre) having anti-inflammatory, antioxidant and anti-apoptotic effects previously reported. The objective of this study was to analyze the effects of eriodictyol on neuronal damage, memory deficits and inflammatory-response of mice subjected to focal cerebral ischemia by permanent meddle cerebral artery occlusion (pMCAO). The animals were treated orally with eriodictyol (1, 2 and 4 mg / kg) or vehicle (5% Tween 80 in saline 0,9%) 30 minutes before, 2 hours after the pMCAO and daily for 4 days. The promoted pMCAOischemic brain damage in animals, this being confirmed by means of detection of a significant increase in the percentage of infarcted areas, the observed sensorimotor deficits and loss of neuronal viability. The eriodictyol reduced the area of cerebral infarction in doses of 1, 2 and 4 mg / kg and prevented the animal-ischemic neurological deficits 24h post-pMCAO...

Assuntos

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Heterotheca ineuloides Cass (Asteraceae), popularly known as árnica mexicana, is widely used in Mexican traditional medicine to treat bruises, dermatological problems, rheumatic pains, and other disorders as cancer. The major constituents in H. inuloides are cadinane type sesquiterpenes, flavonoids and phytosterols. Compounds with a cadinane skeleton have been proved to possess cytotoxic activity against human-tumor cell lines and brine shrimp, and display toxic effects in different animal species. Although this plant has been widely used, there is little available information on the safety and toxicity especially of pure compounds. AIM OF THIS STUDY: Evaluate the potential toxicity of the natural products isolated from H. inuloides and some semisynthetic derivatives. MATERIALS AND METHODS: The toxic aspects of the following natural products isolated from dried flowers of H. inuloides: 7-hydroxy-3,4-dihydrocadalene (1), 7-hydroxycadalene (2), 3,7-dihydroxy-3(4H)-isocadalen-4-one (3), (1R,4R)-1-hydroxy-4H-1,2,3,4- tetrahydrocadalen-15-oic acid (4), D-chiro-inositol (5), quercetin (6), quercetin-3,7,3'-trimethyl ether (7), quercetin-3,7,3',4'-tetramethyl ether (8), eriodictyol-7,4'-dimethyl ether (9), α-spinasterol (10), caryolan-1,9ß-diol (11) and 7-(3,3-dimethylallyloxy)-coumarin (12) as well as the toxic aspects of the semisynthetic compounds 7-acetoxy-3,4-dihydrocadalene (13), 7-benzoxy-3,4-dihydrocadalene (14), 7-acetoxycadalene (15), 7-benzoxycadalene (16), quercetin pentaacetate (17), 7-hydroxycalamenene (18), 3,8-dimethyl-5-(1-methylethyl)-1,2-naphthoquinone (19), and 4-isopropyl-1,6-dimethylbenzo[c]oxepine-7,9-dione (20). Toxic activities of compounds were determined by sulforhodamine B (SRB) assay, Artemia salina assay, RAW264.7 macrophage cells. Additionally, the acute toxicity in mouse of compound 1, the major natural sesquiterpene isolated from the acetone extract, was evaluated. RESULTS: The best cytotoxicity activity was observed for mansonone C (19) on K562 cell line with IC50 1.45 ± 0.14 µM, for 7-hydroxycadalene (2) on HCT-15 cell line with IC50 18.89 ± 1.2 µM, and for quercetin pentaacetate (17) on MCF-7 cell line with IC50 22.57 ± 2.4 µM. Sesquiterpenes mansonone C (19) and 7-hydroxy-3,4-dihydrocadalene (1) caused the strongest deleterious effects against A. salina with IC50 39.4 ± 1.07, and 45.47 ± 1.74 µM, respectively. The number of viable RAW 264.7 cells was reduced with sesquiterpenes 1 and 2 by more than 90%. In addition, the acute study of 1 revealed no lethal effects at 300 mg/kg body weight, however, a reduction in the body weight of mice, morphological changes in the tissues of the liver and kidney and toxic signs were observed at very high doses (2000 mg/kg). CONCLUSION: The results provided evidence for the cytotoxicity of Mexican arnica (H. inuloides) metabolites and may be correlated with one of the popular uses of this plant, in traditional Mexican medicine, as anticancer remedy. Among the active compounds contained in the acetone extract, the cytotoxic activity is mainly ascribable to cadinene type sesquiterpenes. In addition, evidence of acute toxicity suggests that 7-hydroxy-3,4-dihydrocadalene (1) may lead to toxicity at very high doses.

Assuntos

RESUMO

ETHNOPHARMACOLOGY RELEVANCE: GB-2a is a I3-naringenin-II8-eriodictyol compound isolated from Garcinia gardneriana (Planchon & Triana) Zappi, a plant used in folk medicine for the treatment of skin disorders. AIM OF STUDY: In the search for new depigmenting agents, this study was carried out to investigate the in vitro effects of GB-2a isolated from G. gardneriana (Planchon & Triana) Zappi in B16F10 melanoma cells. MATERIALS AND METHODS: The effects of GB-2a were evaluated through determination of melanin biosynthesis in B16F10 melanoma cells in comparison with the reference drug kojic acid (500µM). In parallel, the GB-2a effect was assessed in a cell viability assay. Mushroom tyrosinase activity assays were conducted to verify the effect of this enzyme. In order to ascertain the nature of enzyme inhibition on tyrosinase, kinetics analysis of the GB-2a was performed with L-tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA) substrates. RESULTS: The results showed that GB-2a biflavonoid significantly inhibited the melanin content, without reducing cell viability. GB-2a also showed a strong antityrosinase activity in the mushroom tyrosinase assay. GB-2a inhibited the tyrosinase activity, exerting a mixed inhibition. For the L-tyrosine substrate the inhibition was in non-competitive mode and for L-DOPA it was in uncompetitive mode. CONCLUSION: GB-2a biflavonoid promoted inhibition on tyrosinase activity and reduced melanin biosynthesis in B16F10 cells, which suggests great potential for medical and cosmetic uses as a depigmenting agent.

Assuntos

RESUMO

AbstractVernonanthura tweedieana (Baker) H. Rob., Asteraceae, is used in the Brazilian folk medicine for the treatment of respiratory diseases. In this work the phytochemical investigation of its ethanol extracts as well as the development and validation of an UPLC-PDA method for the quantification of the eriodictyol from the leaves were performed. The phytochemical study for this species lead to the identification of ethyl caffeate, naringenin and chrysoeriol in mixture, eriodictyol from leaves, and the mixture of 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-propan-1-one and evofolin B, apigenin, the mixture of caffeic and protocatechuic acid and luteolin from stems with roots, being reported for the first time for V. tweedieana, except for eriodictyol. The structural elucidation of all isolated compounds was achieved by 1H and 2D NMR spectroscopy, and in comparison with published data. An UPLC-PDA method for quantification of the eriodictyol in leaves of V. tweedieana was developed and validated for specificity, linearity, precision (repeatability and intermediate precision), limit of detection (LOD) and limit of quantification (LOQ), accuracy and robustness. In this study, an excellent linearity was obtained (r2 = 0.9999), good precision (repeatability RSD = 2% and intermediate precision RSD = 8%) and accuracy (average recovery from 98.6% to 99.7%). The content of eriodictyol in the extract of leaves of V. tweedieana was 41.40 ± 0.13 mg/g. Thus, this study allowed the optimization of a simple, fast and validated UPLC-PDA method which can be used to support the quality assessment of this herbal material.

RESUMO

The phytochemical analysis of aerial parts of Cordia globosa, collected in the Municipality of Picuí, State of Paraíba, Brazil, resulted in the isolation and structural identification of narigenin-4',7-dimethyl ether (0.025 g) and eriodictyol (0.015 g). These compounds are the first flavanones aglycones isolated from the genus Cordia.

A análise fitoquímica das partes aéreas de Cordia globosa, coletadas no município de Picuí, PB, Brasil, resultou no isolamento e identificação estrutural da 7,4'-dimetilnarigenina (0,025 g) e eriodictiol (0,015 g). Estas duas flavanonas são as primeiras agliconas, desta classe, isoladas no gênero Cordia.