RESUMO
Nalca is an edible rhubarb-type plant from the southern of Chile; with studies focussing on petiole chemical and biological properties. This work evaluated for the first time the antibacterial capacities of three organs of nalca against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Petiole (P), root (R) and flower (F) ethanolic extracts at three different concentrations (25, 50, 100 mg/mL) were evaluated by means of agar diffusion assay and MIC. The result showed that antibacterial activities are bacteria and concentration dependent, with root having the highest antimicrobial activity of the organs plant studied. Compared to commercial antibiotics, nalca extracts show promising control over Ps. aeruginosa. The main polyphenolics of the extracts were identified by UPLC-MS/MS, observing for the first time caffeic, coumaric and gallic acids presence in all samples, with quercetin and rutin determined in petiole and flower extracts only. Our results contribute to better understanding of nalca attributes as potential source of antibacterial compounds to be used in nutraceutical, cosmetic and food industry.
Assuntos
Extratos Vegetais , Espectrometria de Massas em Tandem , Antibacterianos/farmacologia , Cromatografia Líquida , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologiaRESUMO
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 OxigênioRESUMO
BACKGROUND: The biodegradable and biocompatible nature of pectin-based films is of particular interest in wound dressing applications, due to its non-toxicity, pH-sensitivity and gelling activity. An approach to improve the mechanical properties, the release profile of bioactive compounds as well as the performance in wet environments of pectin-based films is mixing with other biopolymers. OBJECTIVE: To prepare hydrocolloid films based on crosslinked pectin / starch blend loaded with bioactive extracts from leaves of G. tinctoria and U. molinae with controlled release of bioactive compounds and healing property. METHODS: The hydrocolloid films were characterized by FTIR, SEM, and TGA-FTIR techniques and their tensile properties, water uptake, and polyphenolic release profile in aqueous media were evaluated. The dermal anti inflammatory activity of the hydrocolloid films was assessed by the mouse ear inflammation test. The wound healing property of the loaded hydrocolloid films was explored in a rat model and in a clinical trial (sacrum pressure ulcer). RESULTS: The films showed an adequate water-uptake capacity between 100-160%. The release of active compounds from the hydrocolloid films followed the Korsmeyer-Peppas equation. The mechanical properties of hydrocolloid films were not affected by the plant extracts within the concentration range used. The incorporation of the bioactive extracts in the polysaccharide films inhibited the topical edematous response by about 50%. The topical application of the loaded hydrocolloid film on the pressure ulcer is completely closed after 17 days without showing any adverse reaction. CONCLUSION: A novel hydrocolloid matrix was produced from crosslinked starch-pectin, which exhibited suitable chemical-physical properties to be used as a carrier of plant extracts with wound healing properties.
Assuntos
Anti-Inflamatórios/farmacologia , Reagentes de Ligações Cruzadas/farmacologia , Pectinas/farmacologia , Extratos Vegetais/farmacologia , Úlcera por Pressão/tratamento farmacológico , Amido/farmacologia , Cicatrização/efeitos dos fármacos , Idoso , Animais , Anti-Inflamatórios/química , Bandagens , Coloides/química , Coloides/farmacologia , Reagentes de Ligações Cruzadas/química , Feminino , Humanos , Magnoliopsida/química , Masculino , Camundongos , Camundongos Endogâmicos , Myrtaceae/química , Pectinas/química , Extratos Vegetais/química , Folhas de Planta/química , Úlcera por Pressão/patologia , Ratos , Ratos Sprague-Dawley , Amido/químicaRESUMO
The full UHPLC-MS metabolome fingerprinting and anti-Helicobacter pylori effect of Gunnera tinctoria (Molina) Mirb. (Nalca) total extract (GTE) and fractions prepared from its edible fresh petioles were evaluated. The activity of G. tinctoria against H. pylori strains ATCC 45504 and J99 was assessed in vitro by means of agar diffusion assay, Minimum Inhibition Concentration (MIC), and Minimum Bactericidal Concentration (MBC), while killing curve and transmission electronic microscopy (TEM) were conducted in order to determine the effect of the plant extract on bacterial growth and ultrastructure. Additionally, the inhibitory effect upon urease was evaluated using both the Jack Bean and H. pylori enzymes. To determine which molecules could be responsible for the antibacterial effects, tentative identification was done by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap®-HR-MS). Furthermore, the total G. tinctoria extract was fractionated using centrifugal partition chromatography (CPC), giving four active fractions (1-4). It was determined that the crude extract and centrifugal partition chromatography fractions of G. tinctoria have a bactericidal effect being the lowest MIC and MBC = 32 µg/ml. In the killing curves, fraction one acts faster than control amoxicillin. In the urease assay, F3 exhibited the lowest IC50 value of 13.5 µg/ml. Transmission electronic microscopy showed that crude G. tinctoria extract promotes disruption and separation of the cellular wall and outer membrane detachment on H. pylori causing bacterial cell death.
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.