In vitro screening for growth inhibition activity on cancer cell lines of northern Chile highlands shrubs / Triagem in vitro da atividade de inibição do crescimento em linhagens celulares de câncer em arbustos das montanhas do norte do Chile

ABSTRACT: Cancer is still one of the leading causes of death worldwide. Many chemotherapeutics from plants have been tested in cancer, such as vinblastine and paclitaxel. The north of Chile, Arica & Parinacota region, is characterized by its vegetal biodiversity due to its unique geographical and climatological conditions, offering an unexplored and unique source of naturally-derived compounds. The present research has considered a screening of 26 highland herbs using an in vitro growth inhibition model in a panel of six cancer cell lines from different tissues. 5 of the 26 studied ethanolic extracts shows strong activity at least in one cell line when tested at 10 µg mL-1. We present a group of plants worthy to be evaluated as promissory extracts. This work is part of the systematic attempt to find new candidates to be used in cancer therapies.

RESUMO: O câncer ainda é uma das principais causas de morte no mundo. Muitos quimioterápicos de plantas foram testados em câncer, como vinblastina e paclitaxel. O norte do Chile, região de Arica e Parinacota, caracteriza-se por sua biodiversidade vegetal devido às suas condições geográficas e climatológicas únicas, oferecendo uma fonte inexplorada e única de compostos de origem natural. A presente pesquisa considerou uma triagem de 26 ervas das terras altas usando um modelo de inibição de crescimento in vitro em um painel de seis linhas celulares de câncer de diferentes tecidos. Cinco, dos 26 extratos etanólicos estudados, mostram forte atividade pelo menos em uma linhagem celular quando testados a 10 µg mL-1. Apresentamos um grupo de plantas dignas de serem avaliadas como extratos promissórios. Este trabalho faz parte da tentativa sistemática de encontrar novos candidatos para serem usados ​​em terapias contra o câncer.

Improvement of endothelial function by Gunnera tinctoria extract with antioxidant properties

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.

Potential of Baccharis alnifolia Meyen & Walpan (Chilka) from northern Chile used as a medicinal infusion / Potencial de Baccharis alnifolia Meyen & Walpan (Chilka) do norte do Chile usado como infusão medicinal

ABSTRACT: Baccharis alnifolia Meyen & Walp. is a native and medicinal, Chilean Altiplano herb that is used as a poultice and also consumed as an infusion to relieve inflammation. This study evaluated the antioxidant and cytotoxic effect of the ethanolic extract of B. alnifolia and their infusion. It was reported that the ethanol extract contains 4.42 mg GAE/g of dry weight and the infusion contains 35.86 mg GAE/L of total polyphenols. Also, it determined the antioxidant capacity using Ferric reducing antioxidant power (FRAP), Oxygen Radical Absorbance Capacity (ORAC) and Trolox equivalent antioxidant capacity (TEAC) assay. Moreover, seven metabolites including between phenolic acids and flavonoids were identified for the first time in both extracts of the medicinal plant Baccharis alnifolia. The UHPLC-DAD chromatograms revealed the majority presence of ferulic acid and luteolin, both could be responsible for the antioxidant and cytotoxic activity. Furthermore, we realized a preliminary screening of cytotoxicity in different tumor cell lines, finding that these extracts have cytotoxic potential on kidney cells.

RESUMO: Baccharis alnifolia Meyen & Walp. é uma erva altiplana nativa e medicinal, chilena que é usada como cataplasma e também consumida como uma infusão para aliviar a inflamação. Este estudo avaliou o efeito antioxidante e citotóxico do extrato etanólico de B. alnifolia e sua infusão. Verificou-se que o extrato etanólico contém 4,42 mg GAE / g de peso seco e a infusão contém 35,86 mg GAE / L de polifenóis totais. Além disso, determinou a capacidade antioxidante utilizando o poder antioxidante redutor de Fração (FRAP), Capacidade de Absorção Radical de Oxigênio (ORAC) e capacidade antioxidante equivalente de Trolox (TEAC). Além disso, sete metabólitos, entre ácidos fenólicos e flavonóides, foram identificados pela primeira vez em ambos os extratos da planta medicinal Baccharis alnifolia. Os cromatogramas UHPLC-DAD revelaram a presença majoritária de ácido ferúlico e luteolina, ambos podendo ser responsáveis pela atividade antioxidante e citotóxica. Além disso, realizamos uma triagem preliminar da citotoxicidade em diferentes linhagens de células tumorais, descobrindo que esses extratos têm potencial citotóxico nas células renais.

UHPLC high resolution orbitrap metabolomic fingerprinting of the unique species Ophryosporus triangularis Meyen from the Atacama Desert, Northern Chile

ABSTRACT High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in plants and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. In this work, several phenolic compounds including eleven phenolic acids, two fatty acids, two chromones and fourteen flavones were rapidly identified in the methanolic extracts of aerial parts and flowers of the unique Chilean species Ophryosporus triangularis Meyen, Asteraceae, growing in the Atacama Desert by means of ultrahigh resolution liquid chromatography orbitrap MS analysis (UHPLC-PDA-OT-MS) for the first time. The UHPLC-MS fingerprint generated can be used for the authentication of this endemic species. The methanolic extracts of the aerial parts and flowers showed also antioxidant capacities (65.34 ± 1.32 and 52.41 ± 1.87 µg/ml in the DPPH assay, 184.88 ± 13.22 and 196.80 ± 13.28 µmol TE/g dry weight in the ferric reducing power assay and 56.17 ± 3.03 and 65.41 ± 1.96% in the superoxide anion scavenging assay, respectively).