RESUMO
The Chilean hazelnut (Gevuina avellana Mol., Proteaceae) is a southern South American nut consumed as a snack and included in different preparations of traditional Chilean cuisine. Recently we described the fatty acid profile, oxylipins, phenolic compounds, as well as the antioxidant capacity. The main compounds of the phenolic-enriched extract were only tentatively identified by spectrometric means. In the present work, we describe the isolation and full characterization of a cyclic dipeptide cyclo(Arg-Trp) and other compounds from the phenolic enriched extracts of the G. avellana cotyledons. Compounds were isolated by means of counter-current chromatography and structures were established by spectroscopic and spectrometric methods. This is the first report on small peptides in G. avellana and adds evidence on the possible beneficial effects of this nut in human health.
Assuntos
Cotilédone/química , Dipeptídeos , Peptídeos Cíclicos , Proteaceae/química , Dipeptídeos/química , Dipeptídeos/isolamento & purificação , Peptídeos Cíclicos/química , Peptídeos Cíclicos/isolamento & purificaçãoRESUMO
Roupala montana Aubl. (Proteaceae) is a typical savannah species and native to tropical South America that has a moderate mortality for adult forms of Schistossoma mansoni. Because this species has been little studied, the aim of this investigation was to evaluate the influence of R. montana extract on DNA damage induced by methyl methanesulfonate (MMS) in peripheral blood cells and liver of Swiss mice using the micronucleus and comet assay, respectively. R. montana dichloromethane extract was prepared from a stock solution (0.5 mg/mL) in 5% dimethyl sulfoxide in water. Animals received a single dose of different concentrations of R. montana (5, 10 and 20 mg/kg body weight) by gavage (0.5 mL/animal). For antigenotoxicity assessment, different concentrations of R. montana were administered simultaneously with MMS diluted in water (40 mg/kg, intraperitoneally; 0.3 mL/animal). Peripheral blood and hepatocyte samples were obtained 48 and 24 h after treatment, respectively. Results showed that R. montana administered alone indicated the absence of genotoxicity in the mouse micronucleus or comet assay. On the other hand, administration of different doses of R. montana concomitantly with MMS led to a significant reduction in frequency of micronucleated polychromatic erythrocytes and DNA damage, when compared to the group treated only with MMS. Further, for the micronucleus assay, the gradual increase of R. montana concentration led to a proportional increase in the reduction of genotoxicity induced by MMS, indicating a dose-response relationship.
Assuntos
DNA/efeitos dos fármacos , Extratos Vegetais/farmacologia , Proteaceae/química , Animais , Ensaio Cometa , Relação Dose-Resposta a Droga , Fígado/efeitos dos fármacos , Fígado/metabolismo , Metanossulfonato de Metila , Camundongos , Testes para MicronúcleosRESUMO
In this study we evaluated the antioxidant and antihyperglycemic activity in vitro of the extracts obtained with solvents: hexane, ethyl acetate and methanol, of the medicinal plant Oreocallis grandiflora (cucharillo), collected in the Saraguro indian community of the province Loja, southern Ecuador. The antioxidant activity was evaluated by the tests: DPPH, FOLIN-CIOCALTEU and beta-CLAMS, while the antihyperglycemic activity was determined by inhibition assay á-amylase and alpha-glucosidase. The samples were diluted to different concentrations and the reading was performed in a UV spectrophotometer, using as positive control á-tocopherol for DPPH and Folin-ciocalteu test, trolox for beta-CLAMS test, and Glucobay® for testing alpha-amylase and alpha-glucosidase.The results are expressed as IC50, these show that the methanol extract of Oreocallis grandiflora has inhibitory effect on alpha-amylase, the IC50 is 109 ug/ml, compared to 126 ug/ ml of Glucobay®. It also shows inhibitory effect on á-glucosidase, the IC50 is 3 ug/ml compared to 1316 ug/ml of Glucobay®. It also shows antioxidant activity, its IC50 is 15 ug/ml compared to 5 ug/ml of á-tocopherol.
En el presente trabajo se evaluó la actividad antioxidante y antihiperglucemiante in vitro de los extractos obtenidos con los solventes: hexano, acetato de etilo y metanol, de la planta medicinal Oreocallis grandiflora (cucharillo), recolectada en la comunidad indígena de Saraguro en la provincia de Loja, al sur del Ecuador. La actividad antioxidante fue evaluada a través de los ensayos: DPPH, FOLIN-CIOCALTEU y beta-CLAMS, mientras que la actividad antihiperglucemiante fue determinada por el ensayo de inhibición de alfa- amilasa y alfa-glucosidasa. El extracto metanólico de Oreocallis grandiflora presenta efecto inhibitorio sobre la enzima alfa-amilasa, su concentración inhibitoria (CI50) es de 109 ug/ml, frente a 126 ug/ml del control positivo Glucobay®. Además, muestra efecto inhibitorio sobre la enzima alfa-glucosidasa, su concentración inhibitoria (CI50) es de 3 ug/ml, frente a 1316 ug/ml del Glucobay®. Muestra también actividad antioxidante, su concentración inhibitoria (CI50) es de 15 ug/ml, frente a 5 ug/ml del alfa-tocoferol.