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1.
J AOAC Int ; 107(1): 140-145, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-37819769

RESUMO

BACKGROUND: Cannabis sativa is known to produce a class of terpenophenolic compounds named cannabinoids. The two main ones are cannabidiol (CBD) and tetrahydrocannabinol (THC), which have therapeutic properties. In the development of cannabis-based preparations, it is important to have suitable analytical methods for the analysis of the principal cannabinoids. OBJECTIVE: This study aimed to develop and validate a simple and rapid HPLC method with photodiode array detection for determination of CBD and THC in Cannabis sativa oil extract and infused ice cream, including a stability study. METHOD: Chromatographic separation of CBD and THC was performed with a C18 column, with a mobile phase consisting of acetonitrile and water with formic acid (80 + 20 v/v) in isocratic elution mode, with detection at 208 nm for CBD and 280 nm for THC and 1.0 mL/min flow rate. RESULTS: The method was linear over a range of 1-5 µg/mL for CBD, and 20-100 µg/mL for THC; the relative standard deviation was <3.6%, the recovery ranged between 98.8 and 102.5% for oil and between 84 and 94% for ice cream, QL was 0.33 µg/mL for CBD and 2.30 µg/mL for THC, and the assay demonstrated adequate selectivity. CBD and THC were stable for at least 28 days under light protection at 22°C, 4°C, and -20°C in the oil and for at least 60 days at -20°C in the ice cream. CONCLUSIONS: The results showed that the method was suitable for quantitative determination of CBD and THC in Cannabis sativa oil extract and infused ice cream, and it is useful for quality control purposes. HIGHLIGHTS: The method is simple and fast, and it is useful for the quality control of a new product corresponding to an ice cream based on a Cannabis sativa oil extract.


Assuntos
Canabidiol , Canabinoides , Cannabis , Sorvetes , Canabinoides/análise , Cannabis/química , Dronabinol/análise , Sorvetes/análise , Canabidiol/análise , Extratos Vegetais/química
2.
Rev. chil. cardiol ; 42(2)ago. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1515099

RESUMO

Objetivo: Obtener un fitofármaco a base de extracto seco de limón con estándares de calidad, procesamiento amigable con el medio ambiente y con antecedentes de efectividad y seguridad, evaluando sus efectos en pacientes hipertensos con frecuentes crisis hipertensivas. Métodos y resultados: Se seleccionó la población de limónes de las Regiones Metropolitana y Coquimbo con las concentraciones más altas de ácido ascórbico y flavonoides totales, respectivamente. Se utilizó liofilización para obtener jugo de limón en polvo. Sólo durante el período de estudio, se informó un caso de aumento/ crisis hipertensiva. La formulación con la concentración más alta de ácido ascórbico disminuyó la presión arterial sistólica y diastólica en 16 mmHg desde 10 minutos hasta 60 minutos. Por otro lado, la formulación con mayor concentración de flavonoides disminuyó la presión arterial en 12 a 30 mmHg desde 5 a 60 minutos. Conclusión: Se obtuvo un producto innovador como complemento al manejo de los aumentos de presión arterial. Los principios activos con mayor contribución al mecanismo antihipertensivo del jugo de limón corresponden a compuestos fenólicos, específicamente, flavonoides.


Aim: To obtain a product based on a dry extract of standardized phytodrug lemon with high quality standards, using an environmentally friendly process; to evaluate its effects in hypertensive patients suffering frequent episodes of hypertensive crisis. Methods and Results: Lemons with high concentration of ascorbic acid (Coquimbo Region) or total flavonoids (Metropolitan Region) were selected. Lyophilization was used to obtain juice powder. During the study period only one case of hypertensive crisis was reported. The formula with the highest concentration of ascorbic acid decreased systolic and diastolic blood pressure by 16 mmHg from 10 minutes up to 60 minutes. On the other hand, the formula with the highest concentration of flavonoids decreased blood pressure from 12 to 30 mmHg between 5 and 60 minutes. Conclusion: An novel product to help decrease acutely elevated blood pressure was obtained that can be used as a complement to the management of acute blood pressure rises. The active principles with greater contribution to the antihypertensive mechanism of lemon juice corresponded to phenolic compounds, specifically flavonoids.

3.
Appl Microbiol Biotechnol ; 106(24): 8021-8034, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36370157

RESUMO

In this work, extracellular colored metabolites obtained from the filamentous fungi Talaromyces australis and Penicillium murcianum, isolated in the Andean-Patagonian native forests of Chile, were studied as prospect compounds to increase the sustainability of cosmetic products. The chemical and antioxidant properties of these natural pigments were characterized and strategies for their microencapsulation were also studied. UHPLC/MS-MS analyses indicated that the predominant metabolites detected in the cultures of P. murcianum were monascin (m/z = 411.15) and monashexenone (m/z = 319.10), while athrorosin H (m/z = 458.20) and damnacanthal (m/z = 281.05) were detected in cultures of T. australis. ORAC tests revealed that P. murcianum's metabolites had the greatest antioxidant properties with values higher than 2000 µmol of trolox equivalents/g. The fungal metabolites were successfully microencapsulated by ionic gelation into structures made of 1.3% sodium alginate, 0.2% chitosan, and 0.07% hyaluronic acid. The microencapsulation process generated structures of 543.57 ± 0.13 µm of mean diameter (d50) with an efficiency of 30% for P. murcianum, and 329.59 ± 0.15 µm of mean diameter (d50) and 40% efficiency, for T. australis. The chemical and biological characterization show the biotechnological potential of these fungal species to obtain pigments with antioxidant activity that could be useful in the cosmetic industry. The encapsulation process enables the production of easy-to-handle dry powder from the fungal metabolites, which could be potentially marketed as a functional cosmetic ingredient. KEY POINTS: • The predominant fungal pigments were of azaphilone and anthraquinoid classes. • The fungal pigments showed high antioxidant activity by ORAC assay. • Fungal pigment microcapsules obtained by ionic gelation were characterized.


Assuntos
Antioxidantes , Biotecnologia
4.
Biol Res ; 53(1): 55, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228801

RESUMO

BACKGROUND: Gunnera tinctoria has been collected by Mapuche-Pewenche people for food and medicinal purposes. The high polyphenol content of methanolic extract from G. tinctoria leaves with chemical constituents such as ellagic acid and quercetin derivatives suggests its application to prevent endothelial dysfunction and oxidative stress. The aim of this study was to provide evidence of the protective effect of this extract on endothelial function by reducing oxidative stress induced by high D-glucose and H2O2, as well as by stimulating nitric oxide (NO) levels in human umbilical vein endothelial cells (HUVECs). RESULTS: A methanolic extract with a high content of polyphenols (520 ± 30 mg gallic acid equivalents/g dry extract) was obtained from G. tinctoria leaves. Its main constituent was ellagic acid. The results of Ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays of the extract confirmed its antioxidant activity by inhibition pathway of radical species. The incubation of HUVECs with the extract decreased the apoptosis and reactive oxygen species (ROS) synthesis induced by high extracellular concentration of D-glucose or hydrogen peroxide. The extract increased endothelial NO levels and reduced vasoconstriction in human placental vessels. CONCLUSIONS: This study provides evidence about the antioxidant and endothelial protective properties of methanolic G. tinctoria leaf extract. The extract improves the availability of NO in HUVECs, inhibiting the production of ROS and vasoconstriction.


Assuntos
Antioxidantes/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Peróxido de Hidrogênio , Estresse Oxidativo , Extratos Vegetais/farmacologia , Apoptose , Feminino , Humanos , Polifenóis/farmacologia , Gravidez , Espécies Reativas de Oxigênio
5.
Biol. Res ; 53: 55-55, 2020. ilus, graf, tab
Artigo em Inglês | LILACS | ID: biblio-1505781

RESUMO

BACKGROUND: Gunnera tinctoria has been collected by Mapuche-Pewenche people for food and medicinal purposes. The high polyphenol content of methanolic extract from G. tinctoria leaves with chemical constituents such as ellagic acid and quercetin derivatives suggests its application to prevent endothelial dysfunction and oxidative stress. The aim of this study was to provide evidence of the protective effect of this extract on endothelial function by reducing oxidative stress induced by high D-glucose and H2O2, as well as by stimulating nitric oxide (NO) levels in human umbilical vein endothelial cells (HUVECs). RESULTS: A methanolic extract with a high content of polyphenols (520 ± 30 mg gallic acid equivalents/g dry extract) was obtained from G. tinctoria leaves. Its main constituent was ellagic acid. The results of Ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays of the extract confirmed its antioxidant activity by inhibition pathway of radical species. The incubation of HUVECs with the extract decreased the apoptosis and reactive oxygen species (ROS) synthesis induced by high extracellular concentration of D-glucose or hydrogen peroxide. The extract increased endothelial NO levels and reduced vasoconstriction in human placental vessels. CONCLUSIONS: This study provides evidence about the antioxidant and endothelial protective properties of methanolic G. tinctoria leaf extract. The extract improves the availability of NO in HUVECs, inhibiting the production of ROS and vasoconstriction.


Assuntos
Humanos , Feminino , Gravidez , Extratos Vegetais/farmacologia , Estresse Oxidativo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Peróxido de Hidrogênio , Antioxidantes/farmacologia , Espécies Reativas de Oxigênio , Apoptose , Polifenóis/farmacologia
6.
Rev Chilena Infectol ; 33(4): 433-437, 2016 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-27905627

RESUMO

INTRODUCTION: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. OBJECTIVE: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. METHOD: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. RESULTS: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. DISCUSSION: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.


Assuntos
Inseticidas/farmacologia , Óleos Voláteis/farmacologia , Pediculus/efeitos dos fármacos , Animais , Bioensaio , Eucalyptus , Óleo de Eucalipto , Humanos , Monoterpenos/farmacologia
7.
Rev. chil. infectol ; 33(4): 433-437, ago. 2016. graf, tab
Artigo em Espanhol | LILACS | ID: biblio-830114

RESUMO

Introduction: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. Objective: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. Method: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population. Results: The results showed 100% effectiveness; short time of death, ovicidal action, activity on the adhesion of the egg, and low toxicity. Discussion: In addition to great effect, the inability of the parasite to become resistant to the chemical composition of the essential oil makes this formulation an alternative to the problem of head lice solution.


Introducción: La pediculosis capitis es un problema de salud pública con una alta prevalencia. La aparición de resistencia del parásito a los pediculicidas convencionales es de gran preocupación a nivel mundial. Objetivo: Desarrollar alternativas pediculicidas, efectivas y seguras, en base al aceite esencial de Eucaliptus globulus. Método: A través de bioensayos se establecieron rangos de concentraciones activas del aceite esencial, y se procedió al desarrollo de una forma farmacéutica, estandarizada, estable, evaluando sus efectos en nuestra población. Resultados: Los resultados mostraron 100% de efectividad; corto tiempo de muerte, acción ovicida, actividad sobre la adherencia del huevo, y baja toxicidad. Discusión: Además de la gran efectividad, la imposibilidad del parásito de adquirir resistencia a la composición química del aceite esencial hace de esta formulación una solución alternativa al problema de la pediculosis.


Assuntos
Humanos , Animais , Pediculus/efeitos dos fármacos , Óleos Voláteis/farmacologia , Inseticidas/farmacologia , Bioensaio , Monoterpenos/farmacologia , Eucalyptus , Óleo de Eucalipto
8.
J Membr Biol ; 249(3): 349-61, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26809653

RESUMO

In order to gain insight into the molecular mechanism of the antioxidant properties of Solanum crispum, aqueous extracts of its leaves were assayed on human erythrocytes and molecular models of its membrane. Phenolics and alkaloids were detected by HPLC-MS. Scanning electron and defocusing microscopy showed that S. crispum changed erythrocytes from the normal shape to echinocytes. These results imply that molecules present in the aqueous extracts were located in the outer monolayer of the erythrocyte membrane. Dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) were chosen as representative of phospholipid classes located in the outer and inner monolayers of the erythrocyte membrane, respectively. X-ray diffraction showed that S. crispum preferentially interacted with DMPC bilayers. Experiments regarding its antioxidant properties showed that S. crispum neutralized the oxidative capacity of HClO on DMPE bilayers; defocusing microscopy and hemolysis assays demonstrated the protective effect of S. crispum against the oxidant effects of HClO on human erythrocytes.


Assuntos
Antioxidantes/farmacologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Extratos Vegetais/farmacologia , Solanum/química , Cromatografia Líquida de Alta Pressão , Eritrócitos/citologia , Eritrócitos/ultraestrutura , Hemólise/efeitos dos fármacos , Humanos , Bicamadas Lipídicas , Espectrometria de Massas , Extratos Vegetais/química , Polifenóis/química , Polifenóis/farmacologia , Difração de Raios X
9.
Bol. latinoam. Caribe plantas med. aromát ; 14(1): 21-32, ene.2015. ilus, tab, graf
Artigo em Espanhol | LILACS | ID: lil-795830

RESUMO

Diabetes mellitus type 2 is a metabolic disorder characterized by chronic hyperglycemia, and an important cardiovascular risk factor with a high morbidity and mortality worldwide. Phytotherapy can be an useful complement in the treatment of chronic diseases, so the hypoglycemic effect of Bauhinia forficata (L) subsp. pruinosa (Fabaceae) was evaluated, as used in Chilean traditional medicine. The content of rutin (R) and trigonelline (T) in aqueous extracts (0.15 and 1.0 percent infusions) and lyophilized extract from leaves of B. forficata were determined by HPLC. It was obtained 2.80 ugR/mL and 2.87 ugT/mL for 0.15 percent infusion, 12.48 ugR/mL and 16.24 ugT/mL for 1.0 percent infusion, and 5.70 ugR/mL and 8.14 ugT/mL for the lyophilized extract (0.1percent). Subsequently, a pilot clinical study in diabetic and prediabetic volunteers (n = 15) was performed, taking one dose of the 0.15 percent infusion, three times a day after meals, for 3 months. The results showed a significant statistically reduction in percent of HbA1c of 0.57 +/- 0.83 (p = 0.0179), suggesting that the 0.15 percent infusion of B. forficata could be useful in the prevention or complementary treatment of diabetes...


La diabetes mellitus tipo 2 es una alteración metabólica caracterizada por hiperglicemia crónica, y un importante factor de riesgo cardiovascular con elevada morbimortalidad a nivel mundial. La Fitoterapia puede ser un complemento útil en el tratamiento de enfermedades crónicas, por lo que se evaluó el efecto hipoglicemiante de Bauhinia forficata (L) subsp. pruinosa (Fabaceae), según su uso en medicina tradicional Chilena. Se determinó mediante HPLC el contenido de rutina (R) y trigonelina (T) en infusos (0.15 por ciento y 1.0 por ciento) y extracto acuoso liofilizado de las hojas de B. forficata. Se obtuvo para el infuso 0.15 por ciento = 2.80 ugR/mL y 2.87 ugT/mL, infuso 1.0 por ciento = 12.48 ugR/mL y 16.24 ugT/mL, y en el extracto liofilizado 0.1 por ciento = 5.70 ugR/mL y 8.14 ugT/mL. Posteriormente, se realizó un estudio clínico piloto en voluntarios diabéticos y prediabéticos (n = 15), tomando una dosis del infuso al 0.15 por ciento, tres veces al día después de las comidas, durante 3 meses. Los resultados mostraron una reducción estadísticamente significativa del por ciento de HbA1c de 0.57 +/- 0.83 (p = 0.0179), sugiriendo que el infuso de hojas de B. forficata (0.15 por ciento) podría ser útil en la prevención o tratamiento complementario de la diabetes...


Assuntos
Humanos , Bauhinia/química , /tratamento farmacológico , Extratos Vegetais/administração & dosagem , Hipoglicemiantes/administração & dosagem , Alcaloides/análise , Cromatografia Líquida de Alta Pressão , Extratos Vegetais/química , Medicina Tradicional , Fitoterapia , Rutina/análise
10.
J Membr Biol ; 247(8): 703-12, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24928227

RESUMO

Ugni molinae is an important source of molecules with strong antioxidant activity widely used as a medicinal plant in Southern Chile-Argentina. Total phenol concentration from its fruit extract was 10.64 ± 0.04 mM gallic acid equivalents. Analysis by means of HPLC/MS indicated the presence of the anthocyanins cyanidin and peonidin, and the flavonol quercitin, all in glycosylated forms. Its antioxidant properties were assessed in human erythrocytes in vitro exposed to HClO oxidative stress. Scanning electron microscopy showed that HClO induced an alteration in erythrocytes from a normal shape to echinocytes; however, this change was highly attenuated in samples containing U. molinae extracts. It also had a tendency in order to reduce the hemolytic effect of HClO. In addition, X-ray diffraction experiments were performed in dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine bilayers, classes of lipids preferentially located in the outer and inner monolayers, respectively, of the human erythrocyte membrane. It was observed that U. molinae only interacted with DMPC. Results by fluorescence spectroscopy on DMPC large unilamellar vesicles and isolated unsealed human erythrocyte membranes also showed that it interacted with the erythrocyte membrane and DMPC. It is possible that the location of U. molinae components into the membrane outer monolayer might hinder the diffusion of HClO and of free radicals into cell membranes and the consequent decrease of the kinetics of free radical reactions.


Assuntos
Antioxidantes/farmacologia , Eritrócitos/efeitos dos fármacos , Frutas/química , Hemólise/efeitos dos fármacos , Myrtaceae/química , Extratos Vegetais/farmacologia , Antocianinas/análise , Membrana Eritrocítica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Difração de Raios X
11.
Phytother Res ; 28(11): 1637-45, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24853276

RESUMO

In this work, the anti-Helicobacter pylori effect of an aqueous extract from dried leaves of Peumus boldus Mol. (Monimiaceae) was evaluated. This extract displayed high inhibitory activity against H. pylori urease. Therefore, in order to clarify the type of substances responsible for such effect, a bioassay-guided fractionation strategy was carried out. The active compounds in the fractions were characterized through different chromatographic methods (RP-HPLC; HILIC-HPLC). The fraction named F5 (mDP = 7.8) from aqueous extract was the most active against H. pylori urease with an IC50 = 15.9 µg gallic acid equivalents (GAE)/mL. HPLC analysis evidenced that F5 was composed mainly by catechin-derived proanthocyanidins (LC-MS and phloroglucinolysis). The anti-adherent effect of boldo was assessed by co-culture of H. pylori and AGS cells. Both the aqueous extract and F5 showed an anti-adherent effect in a concentration-dependent manner. An 89.3% of inhibition was reached at 2.0 mg GAE/mL of boldo extract. In conjunction, our results suggest that boldo extract has a potent anti-urease activity and anti-adherent effect against H. pylori, properties directly linked with the presence of catechin-derived proanthocyanidins.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Biflavonoides/farmacologia , Catequina/farmacologia , Helicobacter pylori/efeitos dos fármacos , Peumus/química , Extratos Vegetais/farmacologia , Proantocianidinas/farmacologia , Urease/antagonistas & inibidores , Adenocarcinoma , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Helicobacter pylori/enzimologia , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Polifenóis/química
12.
Biochim Biophys Acta ; 1838(1 Pt B): 266-77, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23954587

RESUMO

This report presents evidence that the following Solanum steroids: solasodine, diosgenin and solanine interact with human erythrocytes and molecular models of their membranes as follows: a) X-ray diffraction studies showed that the compounds at low molar ratios (0.1-10.0mol%) induced increasing structural perturbation to dimyristoylphosphatidylcholine bilayers and to a considerable lower extent to those of dimyristoylphosphatidylethanolamine; b) differential scanning calorimetry data showed that the compounds were able to alter the cooperativity of dimyristoylphosphatidylcholine, dimyristoylphosphatidylethanolamine and dimyristoylphosphatidylserine phase transitions in a concentration-dependent manner; c) in the presence of steroids, the fluorescence of Merocyanine 540 incorporated to the membranes decreased suggesting a fluidization of the lipid system; d) scanning electron microscopy observations showed that all steroids altered the normal shape of human erythrocytes inducing mainly echinocytosis, characterized by the formation of blebs in their surfaces, an indication that their molecules are located into the outer monolayer of the erythrocyte membrane.


Assuntos
Diosgenina/química , Membrana Eritrocítica/química , Bicamadas Lipídicas/química , Alcaloides de Solanáceas/química , Solanina/química , Varredura Diferencial de Calorimetria , Dimiristoilfosfatidilcolina/química , Diosgenina/farmacologia , Membrana Eritrocítica/efeitos dos fármacos , Corantes Fluorescentes/química , Humanos , Microscopia Eletrônica de Varredura , Transição de Fase/efeitos dos fármacos , Fosfatidiletanolaminas/química , Fosfatidilserinas/química , Pirimidinonas/química , Espalhamento a Baixo Ângulo , Alcaloides de Solanáceas/farmacologia , Solanina/farmacologia , Difração de Raios X
13.
Rev. bras. farmacogn ; 23(1): 44-50, Jan.-Feb. 2013. ilus
Artigo em Inglês | LILACS | ID: lil-666168

RESUMO

In the present work we carried out a comparative study of total phenolic contents and antioxidant capacity of aqueous leaf extracts of Ugni molinae Turcz., Myrtaceae (infusion and Soxhlet extracted) prepared from continent and Juan Fernández Island samples. The results revealed that total phenol content (TPC), tannins (TTC) and flavonoids (TFC) for U. molinae extracts (infusion and Soxhlet extracts) from island leaves were 38.5, 56.7 and 37.5% higher than those obtained with leaves from the continent, respectively. Also, HPLC profiles showed important differences between U. molinae populations. In vitro antioxidant capacity (scavenging of DPPH radical) for 1% infusion and aqueous extract (Soxhlet method) of U. molinae from island samples, was 15% greater than from continent samples. Further, in vivo impact of U. molinae intake (1% infusion) was studied in plasma samples obtained from healthy volunteers. Participants that consumed tea prepared with leaves from island population showed higher TBARS reduction and plasma antioxidant capacity (TEAC-CUPRAC) than those who consumed tea prepared with leaves from continental population. The conditions of the territory in which U. molinae populations growth could explain the differences in their composition and activity. According to results, island U. molinae populations could be an important source of study for the development of an antioxidant supplement, and thereby contribute to the use of this species that has becoming an ecological problem in the island.

14.
Chem Biol Interact ; 179(2-3): 413-8, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-19146840

RESUMO

Balbisia peduncularis, also known as "Amancay", is a plant of the Ledocarpaceae family that can be found in the Atacama Desert in northern Chile. Infusions of the plant have long being used in traditional herbal medicine. Its chemical composition indicates the presence of flavonoids, which have antioxidant properties. Aqueous extracts from its stems were prepared to induce their interaction with human erythrocytes and their membrane models in order to elucidate whether this rare and unstudied plant produced perturbations to cell membranes. Scanning electron microscopy (SEM) of intact human red blood cells showed that the extract changed the normal erythrocytes morphology as a function of its concentration, first inducing echinocytes, and then stomatocytes and spherocytes. According to the bilayer couple hypothesis, the shape changes indicated that the flavonoids were first located in the outer monolayer of the erythrocyte membrane, and at the highest assayed concentration in both monolayers. The results obtained by fluorescence spectroscopy measurements of isolated unsealed human erythrocytes (IUM), of unilamellar vesicles (LUV) of dimyristoylphosphatidylcholine (DMPC), and by X-ray diffraction of DMPC and dimyristoylphosphatidylethanolamine (DMPE) multilayers, confirmed this conclusion. In fact, they showed that the plant aqueous extract molecules were located in both the hydrophilic polar head and in the hydrophobic acyl chain regions of the lipid bilayers. As a consequence, perturbations of the phospholipid bilayer packing arrangement were produced.


Assuntos
Membrana Eritrocítica/química , Membrana Eritrocítica/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Flavonoides/química , Flavonoides/farmacologia , Eritrócitos/ultraestrutura , Flavonoides/isolamento & purificação , Humanos , Microscopia Eletrônica de Varredura , Modelos Moleculares , Fosfolipídeos/química , Caules de Planta/química , Espectrometria de Fluorescência , Difração de Raios X
15.
Int J Pharm ; 363(1-2): 85-90, 2008 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-18687390

RESUMO

Aristotelia chilensis (Mol.) Stuntz (A. chilensis), also known as maqui, is a plant of the Elaeocarpaceae family that grows in central and southern Chile as well as southwestern Argentina. Infusions of its leaves have long been used in the traditional native herbal medicine to treat different ailments. Phytochemical studies of the plant's chemical composition of the plant indicate the presence of indolic alkaloids, flavonoids, cianidine glucosides, delfidine, malvidine, petunidine, cumarines and triterpenes. These compounds, particularly the flavonoids, have antioxidant properties. In order to evaluate the mechanisms of its toxicity and their antioxidant properties, the leaves' aqueous extracts were induced to interact with human red cells, their isolated unsealed membranes (IUM), and molecular models of the human erythrocyte membrane. These consisted of multibilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipids classes located in the outer and inner monolayers of the human erythrocyte membrane, and large unilamellar vesicles (LUV) of DMPC. The capacity of A. chilensis aqueous extracts to perturb the bilayer structure of DMPC and DMPE was evaluated by X-ray diffraction, DMPC LUV and IUM were studied by fluorescence spectroscopy, and intact human erythrocytes were observed by scanning electron microscopy (SEM). Results of the present study indicate that aqueous extracts of A. chilensis induced an alteration of human erythrocyte morphology from the normal discoid shape to an echinocytic form, changes that are explained in terms of the extract interaction with the membrane's outer phospholipid monolayer.


Assuntos
Antioxidantes/farmacologia , Elaeocarpaceae , Membrana Eritrocítica/efeitos dos fármacos , Eritrócitos Anormais/efeitos dos fármacos , Flavonoides/farmacologia , Antioxidantes/isolamento & purificação , Forma Celular/efeitos dos fármacos , Dimiristoilfosfatidilcolina/química , Elaeocarpaceae/química , Membrana Eritrocítica/química , Membrana Eritrocítica/ultraestrutura , Eritrócitos Anormais/química , Eritrócitos Anormais/ultraestrutura , Flavonoides/isolamento & purificação , Humanos , Bicamadas Lipídicas , Microscopia Eletrônica de Varredura , Fosfatidiletanolaminas/química , Extratos Vegetais/farmacologia , Folhas de Planta , Espectrometria de Fluorescência , Difração de Raios X
16.
J Sep Sci ; 30(16): 2703-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17763522

RESUMO

In the present study, an RP high performance liquid chromatographic method was developed and validated for the determination of allicin in garlic powder and tablets. Chromatographic separation was carried out on an RP-18(e )column (125 mm x 4 mm), using a mobile phase, consisting of methanol-water (50:50 v/v), at a flow rate of 0.5 mL/min and UV detection at 220 nm. Ethylparaben was used as the internal standard. The assay was linear for allicin concentrations of 5.0-60.0 microg/mL. The RSD for precision was <6.14%. The accuracy was above 89.11%. The detection and quantification limits were 0.27 and 0.81 microg/mL, respectively. This method was used to quantify allicin in garlic powder samples. The results showed that the method described here is useful for the determination of allicin in garlic powder and tablets.


Assuntos
Cromatografia Líquida/métodos , Pós/química , Ácidos Sulfínicos/análise , Comprimidos/química , Dissulfetos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta
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