Improvement of endothelial function by Gunnera tinctoria extract with antioxidant properties

Abstract

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.

Exploring Gunnera tinctoria: From Nutritional and Anti-Tumoral Properties to Phytosome Development Following Structural Arrangement Based on Molecular Docking

“…Gallic acid, ellagic acid, catechin, epicatechin, and quercetin have been described as major phenolics of G. tinctoria [ 8 , 20 ], and all of them are widely known for their antioxidant properties. Based on the hypothesis that the phenolic-enriched fraction of G. tinctoria would exert antitumoral activities in breast and pancreatic cancer cell lines, their effects on cell viability, culture growth, and proliferation were studied.…”

“…Dysentery, diarrhea, circulatory and urinary disorders, high respiratory tract diseases, and gynecological, and obstetric problems, are some examples where G. tinctoria is used in folk medicine [ 7 ]. Moreover, antioxidant, dermal anti-inflammatory, and antifungal activities, as well as improvement of the endothelial function are recent therapeutic activities that have been also reported for G. tinctoria [ 8 ]. Based on this, this plant emerges as a particularly interesting natural source of bioactive compounds.…”

Chondroprotection and Molecular Mechanism of Action of Phytonutraceuticals on Osteoarthritis

“…Since ancient times, Asian countries use turmeric as a spice, safe and beneficial for the body [ 70 , 73 ]. About 90% of the biologically active substances in turmeric is curcumin.…”

“…Rosehip powder is widely used in traditional medicine [ 71 , 73 ]. A meta-analysis of randomized controlled trials (RCT) has shown that rosehip powder reduces pain and reduces the use of analgesics in OA patients [ 51 ].…”

“…The cytokine IL-1β is an important therapeutic target in OA. Another important cytokine in OA is cathepsin B, which degrades aggrecan in matrix metalloproteinase [ 73 , 75 ].…”