Stability of phenolic compounds in grape stem extracts

Grape stem is rich in phenolic compounds, especially stilbenes. These antioxidants can be degraded during the storage of grape stem extracts for long periods of time. The aim of this work was to analyze the stability of Mazuelo stem extracts during storage at 25 and 40◦C, in two different light conditions (amber and transparent vials). The stability of the antioxidants was studied after 2, 4 and 6 months of conservation. Gallic acid and the quercetin derivative concentration were stable throughout the storage period. In contrast, catechin disappeared from all the extracts in just two months of storage. Anthocyanins were significantly affected by temperature, and light enhanced their degradation when the extracts were kept at 40◦C. Resveratrol and viniferin showed a similar behavior. Their concentration decreased from the beginning of storage, and in both cases, they were significantly affected by both temperature and light.This research was funded by the Government of Navarra, grant numbers VARASVI PI022 and PI038.This research was funded by the GOVERNMENT OF NAVARRA, grant numbers VARASVI PI022 and PI038

Phenolic composition of grape stems from different Spanish varieties and vintages

Grape stems are a by‐product from the wine industry that has been underused to date despite having great potential for the agro‐food and cosmetic industries. The aim of the present work was to characterize grape stem extracts obtained from different grape varieties from two vintages (2016 and 2018). Both spectrophotometric and chromatographic methods were used for sample characterization. The results showed that there exist significant differences in antioxidant activity, total phenolic content (TPC) and total flavonoid content (TF) among grape stems from different varieties in each vintage and from different vintage for the same variety. Catechin was the most abundant phenolic compound in all extracts from both vintages. In general, Mazuelo presented higher concentration values of the different phenolic compounds than Garnacha and Tempranillo. It was observed than extreme temperatures and accumulated precipitations, which were higher in the 2016 vintage, had an impact on the polyphenol synthesis. Therefore, grape stems from the 2018 vintage presented higher TPC and TF values than their counterparts from the 2016 vintage. In addition, the statistical analysis revealed that the influence of environmental factor such as light, temperature and precipitations have different impact on the synthesis of polyphenols depending on the family of the specific compound.This research was founded by the Government of Navarra, grant numbers VARASVI PI022 and PI038

A combination of Rosa canina extracts and gold complex favors apoptosis of caco-2 cells by increasing oxidative stress and mitochondrial dysfunction

Given the alarming increase in colorectal cancer (CRC) worldwide, novel therapies are urgently needed. Plant-derived extracts have gained considerable interest in the last years due to their strong anticancer effect mediated by their unique bioactive compounds. Specifically, rosehips from Rosa canina have been successfully tested against several cancer models, including colon cancer. Moreover, gold derivatives are a promising alternative to the current platinum-based drugs commonly used in CRC chemotherapy due to their lack of affinity for DNA. Herein we have investigated the antitumor potential of a drug combination made of acidic polyphenols extracted from R. canina and the gold complex (Au(C=C-2-NC5H4) (PTA)) in Caco-2 cell line as a model of CRC. The combination triggered strong apoptosis mediated by a blockage of the autophagic flux, which might be a consequence of a reactive oxygen species (ROS) increase and mitochondrial dysfunctionality. Our results suggest that the clinical application of plant polyphenols might enhance the anticancer effect of metallodrugs and reduce drug exposure time and therefore its side effects

Nutraceutical composition of three pine bark extracts and their antiproliferative effect on Caco-2 cells

The use of vegetal materials that go unused or by-products of the food industry, for the development of functional foods is very interesting. Pine bark extracts have been useful in medicine and in functional foods, yet, little is known about its antiproliferative properties. In this work, the activity of bark extracts from different Pinus species on human colorectal adenocarcinoma (Caco-2) cells was studied. All these extracts induce cell-cycle arrest and apoptosis in Caco-2 cells through alteration of the mitochondrial membrane potential, release of cytochrome c to cytoplasm and caspase 3 activation. In addition, a significant decrease in ROS generation was also observed in the presence of the extracts tested. The results obtained in this work show that these extracts could be interesting in order to elaborate functional foods and not only for improving their antioxidant properties but also for playing an important role in the treatment of colorectal carcinoma

Reducing SO₂ doses in red wines by using grape stem extracts as antioxidants

SO₂ is a very important wine preservative. However, there are several drawbacks associated with the use of SO₂ in wine. The aim of this work is to evaluate the effect of the partial substitution of SO₂ in the Tempranillo wine by a Mazuelo grape stem extract and by a commercial vine wood extract (Vinetan®). The results were compared with a control sample (with no addition of any extract). After 12 months of storage in a bottle, total anthocyanin content, together with total polyphenol and flavonoid content were slightly higher for control wines than for those treated with extracts. These differences were of little relevance, as no differences in antioxidant activity were found between any of the wines at the end of the study. The sensory analysis revealed that the use of both extracts as partial substitutes of SO₂ could lead to wines with good organoleptic properties, similar or even better to the control ones.This research was funded by the Government of Navarra, grant numbers VARASVI PI022 and PI038.This research was funded by the Government of Navarra, grant numbers VARASVI PI022 and PI038

Therapeutic applications of rose hips from different rosa species

Rosa species, rose hips, are widespread wild plants that have been traditionally used as medicinal compounds for the treatment of a wide variety of diseases. The therapeutic potential of these plants is based on its antioxidant effects caused by or associated with its phytochemical composition, which includes ascorbic acid, phenolic compounds and healthy fatty acids among others. Over the last few years, medicinal interest in rose hips has increased as a consequence of recent research that has studied its potential application as a treatment for several diseases including skin disorders, hepatotoxicity, renal disturbances, diarrhoea, inflammatory disorders, arthritis, diabetes, hyperlipidaemia, obesity and cancer. In this review, the role of different species of Rosa in the prevention of treatment of various disorders related to oxidative stress, is examined, focusing on new therapeutic approaches from a molecular point of view.The work of this group was supported by projects from the Ministerio de Ciencia e Innovación (SAF2016-75441-R), funding from the Gobierno de Aragón/European Regional Development Fund (ERDF) (A-32), and Proyect Interreg Sudoe REDVALUE (SOE1/PI/E0123) Co-financed at 65% by the European Regional (A-32), and Proyect Interreg Sudoe REDVALUE (SOE1/PI/E0123) Co-financed at 65% by the European Regional Development Fund. We are also grateful for the financing of CIBERobn (CB06/03/1012) from the Instituto Carlos III (Spain)

Anti-Inflammatory and chondroprotective effects induced by phenolic compounds from onion waste extracts in ATDC-5 chondrogenic cell line

Osteoarthritis is a prevalent degenerative condition that is closely related to the destruction and inflammation of cartilage. The high prevalence of this pathology exhorts researchers to search for novel therapeutic approaches. Vegetable–fruit wastes have emerged as a promising origin of anti-inflammatory and antioxidant compounds that, in some cases, may also exert chondroprotective effects. This study aims to decipher the potential of onion waste products in the inhibition of molecular events involved in osteoarthritis. Onion extracts showed a high content of phenolic compounds and antioxidant properties. Cytocompatibility was demonstrated in the chondrogenic cell line ATDC-5, exerting viability percentages higher than 90% and a slight increase in the S phase cycle cell. The induction of inflammation mediated by the lipopolysaccharide and onion extracts’ treatment substantially inhibited molecular markers related to inflammation and cartilage degradation, highlighting the promising application of onion extracts in biomedical approaches. The in silico analyses suggested that the results could be attributed to protocatechuic, ellagic, and vanillic acids’ greater cell membrane permeability. Our work provides distinctive information about the possible application of waste onion extracts as functional components with anti-inflammatory and chondroprotective characteristics in osteoarthritis.his work was supported by the Grants: Proyectos en Salud AES 2021 (PI21/00911; ISCIII), CIBER-BBN, CIBEROBN, Ministerio de Ciencia e Innovación-Fondo Europeo de Desarrollo Regional (PID2019-104915RB-I00), Fondo Social Europeo-Gobierno de Aragón (B16_20R) and SUDOE (Redvalue, SOE1/PI/E0123). This research was also funded by European Union’s H2020 research and innovation program under Marie Sklodowska-Curie grant agreement number 801586. G.M. gratefully acknowledges the support from the Miguel Servet Program (MS19/00092; ISCIII). M.P. acknowledges the support from the Gobierno de Aragón fellowship (CUS/581/2020). O.G. is Staff Personnel (I3SNS Stable Researcher) of Xunta de Galicia (Servizo Galego de Saude (SERGAS)) through a research-staff contract (ISCIII)/SERGAS

Rosa canina extracts have antiproliferative and antioxidant effects on caco-2 human colon cancer

The in vitro antiproliferative and antioxidant effects of different fractions of Rosa canina hips on human colon cancer cell lines (Caco-2) was studied. The compounds tested were total extract (fraction 1), vitamin C (fraction 2), neutral polyphenols (fraction 3) and acidic polyphenols (fraction 4). All the extracts showed high cytotoxicity after 72 h, both low and high concentrations. The flow cytometric analysis revealed that all the fractions produce disturbances in the cell cycle resulting in a concomitant cell death by an apoptotic pathway. Changes in the redox status of Caco-2 cells in response to Rosa canina hips were determined. Cells were exposed to hydrogen peroxide in presence of plant fractions and the production of Reactive Oxygen Species (ROS) was significantly decreased. Therefore, our data demonstrate that rosehip extracts are a powerful antioxidant that produces an antiproliferative effect in Caco-2 cells. Therefore, these results predict a promising future for Rosa canina as a therapeutic agent. Thus, this natural plant could be an effective component of functional foods addressed towards colorectal carcinoma.This study was supported by the projects: the Ministry of Science and Innovation (SAF2013-41651), funding from Aragón Regional Government (A-32) and CIBER (Centros de Investigación Biomédica en Red) Sub-program (CIBERobn, CB06/03/1012,) by the Instituto de Salud Carlos III and Proyecto ELENA, EFA 220/11 ELENA