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Chemo-protective activity and characterization of phenolic extracts from Corema album
... For this reason, it can be observed how the induction of oxidative stress in HepG2 cells with H2O2 leads to the increase in the activity of these enzymes in order to reduce the levels of reactive species therein. However, a rapid return to the baseline values of activity of these proteins once the stress is overcome places the cell in a favourable condition to face a new aggression [40]. Therefore, the ability to reduce the levels of the activity of GPx of both the extract and the β-sitosterol at all tested contractions under the conditions of oxidative stress granted them a notable protective effect against this type of alteration. ...
... The plate was kept in an incubator at 37 °C in an atmosphere with 5% CO2 for 24 h. The cells were then treated either with a culture medium (negative control) or with 1 µg/mL of LPSs either in the absence (positive control) or presence of various concentrations of Acanthus extract or β-sitosterol (20,40,60,80, and 100 µg/mL) for 24 h. Subsequently, 100 µL of culture media was taken from each well and 90 µL of 1% sulphanilamide in 5% phosphoric acid in H2O was added. ...
... The measurement of GPx activity was based on the GSH oxidation mediated by the enzyme coupled to the disappearance of NADPH as a cofactor of GR following the protocol of León-González et al. [40]. The GR activity was determined through the decrease in absorbance that occurred due to NADPH oxidation [47]. ...
The rhizomes of Acanthus mollis have traditionally been used for the treatment of several ailments involving inflammation. However, to the best of our knowledge, their chemical composition and pharmacological properties have not been studied until now. As a first approach, this study analyses the A. mollis rhizome hexane extract phytochemistry and its anti-inflammatory and antioxidant capacities in HepG2 and RAW 264.7 cell culture assays. Chemical profiling was performed with gas chromatography mass spectrometry without the modification of native molecules. Free phytosterols (such as β-sitosterol) account for 70% of detected compounds. The anti-inflammatory capacity of the rhizome extract of A. mollis is mediated by the decrease in the NO production in RAW 264.7 that has previously been stimulated with lipopolysaccharide in a dose-dependent manner. Furthermore, HepG2 pre-treatment with the rhizome extract prevents any damage being caused by oxidative stress, both through ROS scavenge and through the antioxidant cellular enzyme system. In this respect, the extract reduced the activity of glutathione peroxidase and reductase, which were stimulated under oxidative stress conditions. Our results suggest that the extract from the rhizomes of A. mollis may constitute a potential source of natural products with anti-inflammatory activity and could validate the traditional use of A. mollis.
... The remaining 13 papers proceeded to the full text review. From those, only 11 were about phenolic compounds' identification in C. album; thus, they were considered eligible for the data extraction [7,[10][11][12][13][14][15][16][17][18][19]. ...
... Stilbenes are known to display a structure with two aromatic rings linked by an ethene bridge. PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids p-hydroxybenzoic acid (R=R1=R2=H) and derivatives Vanillic acid (R=R1=H; R2=OCH3) Protocatechuic acid (R=R1=H; R2=OH) Syringic aid (R=H; R1=R2= OCH3) Gallic acid (R=H; R1=R2=OH) [7,[10][11][12]14] Hydroxicinnamic acids t-Cinnamic acid [12] p-coumaric acid (R=R1=R2=H) Sinapic acid (R=H; R1=R2= OCH3) Ferulic acid (R=R2=H; R1= OCH3) and derivatives Caffeic acid and derivatives (R=R2=H; R1=OH/O-Hexose; R2= H) [7,12,14] Chlorogenic acid ( PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids [7,15,16] Catechin (R=R1=R2=R3=R4=R5=OH) and derivatives [15] Procyanidin (R=H, n=1) and derivatives: -i.e., Procyanidin Dimer type A (R=H, n=2) [15] Flavanones pinocembrin [7] 6-geranylnaringenin [7] Anthocyanins Cyanidin (R1=R2=OH; R3=R4=R5=R6=H) and derivatives -i.e., Cyanidin 3-O-glucoside (R6=glucose) -i.e., Cyanidin 3-O-arabinoside (R6=arabinose) [7] Delphinidin (R1=R2=R3=R4=R5=OH; R6=H) and derivatives: -i.e., Delphinidin 3-O-glucoside (R6= glucose) [7] STILBENES Resveratrol (R1=R2=H) and derivatives: -i.e., Pterostilbene (R1=R2=CH3) -i.e., Stilbene Hexoside (R2=Hexose) [7,15] Moreover, and in accordance with previously described features [20], natural phenolic acids, free or conjugated, can also appear as amides or esters whereas natural flavonoids, free or conjugated, are often esterified to one or two sugar molecules (by one or more hydroxyl groups). [7,15,16] Catechin (R=R1=R2=R3=R4=R5=OH) and derivatives [15] Procyanidin (R=H, n=1) and derivatives: -i.e., Procyanidin Dimer type A (R=H, n=2) [15] Flavanones pinocembrin [7] 6-geranylnaringenin [7] Anthocyanins Cyanidin (R1=R2=OH; R3=R4=R5=R6=H) and derivatives -i.e., Cyanidin 3-O-glucoside (R6=glucose) -i.e., Cyanidin 3-O-arabinoside (R6=arabinose) [7] Delphinidin (R1=R2=R3=R4=R5=OH; R6=H) and derivatives: -i.e., Delphinidin 3-O-glucoside (R6= glucose) [7] STILBENES Resveratrol (R1=R2=H) and derivatives: -i.e., Pterostilbene (R1=R2=CH3) -i.e., Stilbene Hexoside (R2=Hexose) [7,15] Moreover, and in accordance with previously described features [20], natural phenolic acids, free or conjugated, can also appear as amides or esters whereas natural flavonoids, free or conjugated, are often esterified to one or two sugar molecules (by one or more hydroxyl groups). ...
... Stilbenes are known to display a structure with two aromatic rings linked by an ethene bridge. PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids p-hydroxybenzoic acid (R=R1=R2=H) and derivatives Vanillic acid (R=R1=H; R2=OCH3) Protocatechuic acid (R=R1=H; R2=OH) Syringic aid (R=H; R1=R2= OCH3) Gallic acid (R=H; R1=R2=OH) [7,[10][11][12]14] Hydroxicinnamic acids t-Cinnamic acid [12] p-coumaric acid (R=R1=R2=H) Sinapic acid (R=H; R1=R2= OCH3) Ferulic acid (R=R2=H; R1= OCH3) and derivatives Caffeic acid and derivatives (R=R2=H; R1=OH/O-Hexose; R2= H) [7,12,14] Chlorogenic acid ( PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids PHENOLIC ACIDS Benzoic acid [12] Salicilic acid [12] Tannic acid [13] Hydroxibenzoic acids [7,15,16] Catechin (R=R1=R2=R3=R4=R5=OH) and derivatives [15] Procyanidin (R=H, n=1) and derivatives: -i.e., Procyanidin Dimer type A (R=H, n=2) [15] Flavanones pinocembrin [7] 6-geranylnaringenin [7] Anthocyanins Cyanidin (R1=R2=OH; R3=R4=R5=R6=H) and derivatives -i.e., Cyanidin 3-O-glucoside (R6=glucose) -i.e., Cyanidin 3-O-arabinoside (R6=arabinose) [7] Delphinidin (R1=R2=R3=R4=R5=OH; R6=H) and derivatives: -i.e., Delphinidin 3-O-glucoside (R6= glucose) [7] STILBENES Resveratrol (R1=R2=H) and derivatives: -i.e., Pterostilbene (R1=R2=CH3) -i.e., Stilbene Hexoside (R2=Hexose) [7,15] Moreover, and in accordance with previously described features [20], natural phenolic acids, free or conjugated, can also appear as amides or esters whereas natural flavonoids, free or conjugated, are often esterified to one or two sugar molecules (by one or more hydroxyl groups). [7,15,16] Catechin (R=R1=R2=R3=R4=R5=OH) and derivatives [15] Procyanidin (R=H, n=1) and derivatives: -i.e., Procyanidin Dimer type A (R=H, n=2) [15] Flavanones pinocembrin [7] 6-geranylnaringenin [7] Anthocyanins Cyanidin (R1=R2=OH; R3=R4=R5=R6=H) and derivatives -i.e., Cyanidin 3-O-glucoside (R6=glucose) -i.e., Cyanidin 3-O-arabinoside (R6=arabinose) [7] Delphinidin (R1=R2=R3=R4=R5=OH; R6=H) and derivatives: -i.e., Delphinidin 3-O-glucoside (R6= glucose) [7] STILBENES Resveratrol (R1=R2=H) and derivatives: -i.e., Pterostilbene (R1=R2=CH3) -i.e., Stilbene Hexoside (R2=Hexose) [7,15] Moreover, and in accordance with previously described features [20], natural phenolic acids, free or conjugated, can also appear as amides or esters whereas natural flavonoids, free or conjugated, are often esterified to one or two sugar molecules (by one or more hydroxyl groups). ...
Corema (C.) album belongs to the family Ericaceae and can be found in the Iberian Peninsula, especially on the coastal areas facing the Atlantic coast. C. album berries have been used for centuries in traditional medicine. Recent studies have revealed that not only the berries but also the leaves have relevant antioxidant, antiproliferative, and anti-inflammatory properties, bringing this plant to the forefront of discussion. A systematic review of the literature was carried out to summarize the phenolic compounds and bioactive properties identified in C. album berries and leaves and to search for research gaps on this topic. The search was conducted in three electronic databases (PubMed, SCOPUS, and Web of Science) using PRISMA methodology. The inclusion criteria were the chemical compositions of the berries, leaves, or their extracts and their bioactive properties. The exclusion criteria were agronomic and archaeological research. The number of studies concerning phenolic compounds’ composition and the bioactive properties of C. album berries and leaves is still limited (11 articles). However, the variety of polyphenolic compounds identified make it possible to infer new insights into their putative mechanism of action towards the suppression of NF-kB transcription factor activation, the modulation of inflammatory mediators/enzymes, the induction of apoptosis, the modulation of mitogen activated protein kinase, cell cycle arrest, and the reduction of oxidative stress. These factors can be of major relevance concerning the future use of C. album as nutraceuticals, food supplements, or medicines. Nevertheless, more scientific evidence concerning C. album’s bioactivity is required.
... Due to their phenolic structure, the main bioactive components of S. nigra, flavonoids and hydroxycinnamic acids, have a remarkable oxidant scavenging capacity related to the hydrogen-donating ability and the stability of the phenoxyl radicals formed [27]. Our results of the antioxidant capacity in vitro with realistic doses of elderflower extracts seem to support the antioxidant effect observed in cultured cells with similar or comparable doses of other plant extracts also rich in flavonoids and/or hydroxycinnamic acids [28][29][30][31]. Moreover, pre-treatment of SH-SY5Y cells with aqueous or ethanolic extracts (5-25 µg/mL) of elderflower did not significantly affect the phosphorylation of ULK1 at serine 757, neither LC3-II protein expression, suggesting that the autophagy process plays a minor role in the beneficial effects of elderflower ( Figure 6A-C). ...
... Due to their phenolic structure, the main bioactive components of S. nigra, flavonoids and hydroxycinnamic acids, have a remarkable oxidant scavenging capacity related to the hydrogen-donating ability and the stability of the phenoxyl radicals formed [27]. Our results of the antioxidant capacity in vitro with realistic doses of elderflower extracts seem to support the antioxidant effect observed in cultured cells with similar or comparable doses of other plant extracts also rich in flavonoids and/or hydroxycinnamic acids [28][29][30][31]. ...
... In previous works, we have shown a chemo-protective effect with 0.5-50 µg/mL of cocoa phenolic extract [25,28,36], 1-40 µg/mL of Corema album extract [29], 1-50 µg/mL of green coffee bean extract [30] and 0.5-50 µg/mL of cranberry extract [31] on cultured hepatic cells. Similarly, we have reported chemo-protective activity for 0.5-100 µg/mL Vochysia rufa extract [37], 5-25 µg/mL Silybum marianum [38], and 2.5-20 µg/mL cocoa extract [39] in cultured endothelial cells. ...
Sambucus nigra flowers (elderflower) have been widely used in traditional medicine for the relief of early symptoms of common cold. Its chemical composition mainly consists of polyphenolic compounds such as flavonoids, hydroxycinnamic acids, and triterpenes. Although the antioxidant properties of polyphenols are well known, the aim of this study is to assess the antioxidant and protective potentials of Sambucus nigra flowers in the human neuroblastoma (SH-SY5Y) cell line using different in vitro approaches. The antioxidant capacity is first evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Cell viability is assessed by the crystal violet method; furthermore, the intracellular ROS formation (DCFH-DA method) is determined, together with the effect on the cell antioxidant defenses: reduced glutathione (GSH) and antioxidant enzyme activities (GPx, GR). On the other hand, mTORC1 hyperactivation and autophagy blockage have been associated with an increase in the formation of protein aggregates, this promoting the transference and expansion of neurodegenerative diseases. Then, the ability of Sambucus nigra flowers in the regulation of mTORC1 signaling activity and the reduction in oxidative stress through the activation of autophagy/mitophagy flux is also examined. In this regard, search for different molecules with a potential inhibitory effect on mTORC1 activation could have multiple positive effects either in the molecular pathogenic events and/or in the progression of several diseases including neurodegenerative ones.
... The Corema album species includes two subspecies, namely C. album azoricum originally from Azores, Portugal (Calviño-Cancela, 2002) and the C. album ssp album found at the Atlantic coast of the Iberian Peninsula (Oliveira & Dale, 2012;Santos, de Oliveira, Valdiviesso, & de Oliveira, 2014). Like other fruits with similar morphology, the Corema album berry presents antioxidants, such as polyphenols León-González et al., 2012). Phenolic compounds are amongst the most studied antioxidants due to their biological effects as metal chelators, free radical scavengers, modulators of enzyme activity and protectors of signal transduction pathways (Valko et al., 2007). ...
... Additionally, compounds extracted from Corema album leaves, such as dihydrochalcones have shown anticancer properties, as judged by their capacity to induce cell death and decrease cell viability of HT-29 human colon adenocarcinoma cell lines (León-González, Manson, López-Lizaro, Navarro, & Martín-Cordero, 2014;Oliveira, Nunes, Lima, Borralho, Rodrigues, Ferreira, & Ribeiro, 2019). Moreover, treatment of HepG2 cells with phenolic extracts from Corema album berries has prevented oxidative damage to proteins and lipids, induced by stress (León-González et al., 2012), supporting the ancient ethnomedicinal use of the plant (Martínez-Varea et al., 2019). Thus, being the intestine the primary site of action of dietary antioxidants, the health benefits of incorporating the "Camarinha" crowberry in the human diet can be assessed through the effect on enterocyte-like Caco-2 cells. ...
... Acetone has been described as the most efficient solvent to extract Corema album antioxidant/phenolic compounds León-González et al., 2012). Samples (1 g fresh weight) of whole fruits, leaves, flowers, juice, seeds, and dehydrated pulp of Corema album were extracted with 10 mL of acetone/water solvent (70:30, v/v). ...
Edible wild plants are part of the ethnobotanical and gastronomic heritage of different geographical areas. Corema album (L.) D. Don is an endemic species of the dune systems of the Atlantic coast of the Iberian Peninsula. The aerial parts of Corema album are a source of nutrients and antioxidants. The Corema album white berry (Portuguese crowberry) is rich in calcium, iron, and zinc. The plant also shows high phenolic content and antioxidant capacity associated with the leaves, fruit, and flowers. The presence of organic acids, namely phenolic acids, such as hydroxycinnamic acids, and long chain polyunsaturated fatty acids (PUFAs) omega-3 and omega-6 has also been confirmed. Toxicity studies evaluated by cell viability tests with human intestinal epithelium model cells (Caco-2) have shown that, at low concentrations, plant extracts may present beneficial effects.
... C. album's branches and fruits have traditionally played a useful ecological role not only in landscape conservation but also economically for local communities both in Spain and Portugal, due to its use for fuel or for commercialization of its edible fruits [1]. C. album berries were traditionally used in popular medicine as an antipyretic [1,2] and recent studies have discovered important pharmacological properties of its fruits and leaves [3][4][5]. According to León-González et al. [3], extracts from C. album berries and leaves are rich in hydroxycinnamic acids and contain different amounts of flavonoids and stilbenes; they also found that human colon cells pre-treated with C. album fruit and leaf extracts showed an outstanding protection against challenge-induced damage. ...
... C. album berries were traditionally used in popular medicine as an antipyretic [1,2] and recent studies have discovered important pharmacological properties of its fruits and leaves [3][4][5]. According to León-González et al. [3], extracts from C. album berries and leaves are rich in hydroxycinnamic acids and contain different amounts of flavonoids and stilbenes; they also found that human colon cells pre-treated with C. album fruit and leaf extracts showed an outstanding protection against challenge-induced damage. These findings support the traditional use of C. album as a medicinal plant. ...
... Facing the ongoing habitat loss and disturbance in C. album communities, regeneration under natural conditions is really low, both in the northern [7,10] and southern limits of its biogeographical distribution area [9,10,15]. Under this scenario it is necessary to gain knowledge on the mechanisms underlying C. album propagation, not only for maintaining and regenerating degraded C. album populations, but also for future feasible agricultural and pharmacological use [3][4][5][6]. So far there is very limited information on the germination responses of C. album [16] and, to our knowledge, no clonal propagation techniques have been described for this endemic and vulnerable species. ...
In this study, we aimed to explore regeneration possibilities of Corema album (L.) D. Don by determining germination mechanisms and testing vegetative propagation methods. We analyzed seed viability under natural conditions, carried out germination treatments and a greenhouse experiment to study clonal propagation. We confirmed that C. album seeds present physiological dormancy, broken by ingestion by natural dispersers (rabbits and foxes), and that seed viability under natural conditions is lost after one year. In vitro germination was better achieved with a 200 ppm gibberellic acid treatment. Clonal propagation proved to be a successful technique for the production of C. album. Treating cuttings with IBA 0.2, w/v, at 20% resulted in the highest rooting percentage, while planting rooted cuttings in a substrate of perlite with vermiculite 1:1 was essential for plant survival. Our results show that both germination pretreatments and cutting propagation are powerful tools for the production of this valuable species. Both methods could be incorporated for population regeneration in natural habitats, and for the potential establishment of the species as a new crop for consumption and pharmacological purposes.
... The significant dose-dependent reduction in ROS induced by t-BOOH observed with co-and pre-treatment with extract in both cell lines unequivocally support the antioxidant nature of the phenolic components and could be a primary explanation for the reduced oxidative stress and subsequent cell protection. Interestingly, a comparable ROS-quenching capacity has been reported not only in both EA.hy926 and SH-SY5Y cells as referred above [20,21,23,27,28], but also in cultured hepatic cells [38][39][40][41][42], clearly indicating that this chemo-protective effect is not specific of a particular cell type or tissue but an systemic anti-oxidative stress capacity of natural antioxidants. ...
... GPx induces the reduction in cell-damaging peroxide species, along with the conversion of GSH to oxidized glutathione [29,53], whereas GR recycles oxidized glutathione back to GSH [29,53], recovering the steady state of cellular GSH. The increase in GPx and GR activities observed after the noted treatments with t-BOOH unambiguously indicates a positive response of the cell's defense system to face oxidative stress [29,[38][39][40][41][42]. Consequently, during or after induced oxidative stress the antioxidant defense system of the cells pre-treated with D. tortuosum extract rapidly returned to a steady-state condition minimizing cell damage and, thus allowing the cell to deal with further oxidative insults in conditions that are more favorable. ...
It has been proposed that oxidative stress is a pathogenic mechanism to induce cytotoxicity and to cause cardiovascular and neuronal diseases. At present, natural compounds such as plant extracts have been used to reduce the cytotoxic effects produced by agents that induce oxidative stress. Our study aimed to evaluate the antioxidant and cytoprotective capacity of Desmodium tortuosum (D. tortuosum) extract in the co- and pre-treatment in EA.hy926 and SH-SY5Y cell lines subjected to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Cell viability, reactive oxygen species (ROS), nitric oxide (NO), caspase 3/7 activity, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and molecular expression of oxidative stress biomarkers (SOD2, NRF2 and NFκB1) and cell death (APAF1, BAX, Caspase3) were all evaluated. It was observed that the D. tortuosum extract, in a dose-dependent manner, was able to reduce the oxidative and cytotoxicity effects induced by t-BOOH, even normalized to a dose of 200 µg/mL, which would be due to the high content of phenolic compounds mainly phenolic acids, flavonoids, carotenoids and other antioxidant compounds. Finally, these results are indicators that the extract of D. tortuosum could be a natural alternative against the cytotoxic exposure to stressful and cytotoxic chemical agents.
... A funcionalidade ecológica da camarinha, bagas de cor incomum e composição nutricional e fitoquímica de elevado interesse (Oliveira & Dale, 2012;Pimpão et al., 2013), justificam a exploração e valorização de C. album face aos desafios de preservação da biodiversidade, conservação dos ecossistemas dunares, produtividade e eficiência no uso do solo e da água em sistemas agrícolas e de diversificação alimentar. São conhecidos estudos que avaliaram diferentes atributos de qualidade de frutos selvagens de camarinha, incluindo a capacidade antioxidante (León-González et al., 2012;Andrade et al., 2017a;Andrade et al., 2017b) e o perfil fenólico (León-González et al., 2012;Pimpão et al., 2013;León-González et al., 2013;Andrade et al., 2017b). No entanto, todos estes estudos focaram a caracterização destes parâmetros imediatamente após a colheita dos frutos. ...
... A funcionalidade ecológica da camarinha, bagas de cor incomum e composição nutricional e fitoquímica de elevado interesse (Oliveira & Dale, 2012;Pimpão et al., 2013), justificam a exploração e valorização de C. album face aos desafios de preservação da biodiversidade, conservação dos ecossistemas dunares, produtividade e eficiência no uso do solo e da água em sistemas agrícolas e de diversificação alimentar. São conhecidos estudos que avaliaram diferentes atributos de qualidade de frutos selvagens de camarinha, incluindo a capacidade antioxidante (León-González et al., 2012;Andrade et al., 2017a;Andrade et al., 2017b) e o perfil fenólico (León-González et al., 2012;Pimpão et al., 2013;León-González et al., 2013;Andrade et al., 2017b). No entanto, todos estes estudos focaram a caracterização destes parâmetros imediatamente após a colheita dos frutos. ...
The white crowberry goes to the countryside, but the flavour stays at the beach?
White crowberry, Corema album (L.) D. Don, is an endemic species from coastal
ecosystems of the Iberian Peninsula, extremely adapted to extreme temperature
conditions and water constrains. The fruit's white colour, mildly acidic citrus flavour, high nutritional value and antioxidant properties are strong stimuli to promote this species as a multifunctional, resilient and sustainable crop. Despite growing interest in commercially explore the white crowberry as a new crop, major efforts are still needed to implement its viability, sustainable management practices and species conservation. The aim of this study was to compare the quality of cultivated and wild C. album fruit and quality changes during storage (0 ºC, 30 days). Cultivated fruits (id: FC) were collected from plants maintained in a clonal field collection at Herdade Experimental da Fataca.
These plants were propagated from cuttings of plants from praia do Meco. Wild fruits (id: FS) were collected in loco from plants in praia do Meco. Analytical procedures included: CIELab colour, texture (N), soluble solids content (%), titrable acidity (g.100 ml-1), total phenolic content (TPC, mg CAE.100 g-1) and sensorial analysis. The results showed significant differences between FC and FS samples in all the evaluated parameters, except for colour and texture. During storage and irrespective of sample type, significant changes in fruit quality were only found within the first 5 days. No further quality changes (p>0.05) were observed during the remaining storage period. Regarding sensorial evaluation, despite more visually appealing FC samples, FS samples were preferred by panellists based on perceived sweetness and aroma. Notwithstanding, given the results and especially the high TPC levels, it is foreseeable the white crowberry potential to increase the current offer in the small fruit market. Selection studies of white crowberry genotypes are further needed to promote a new viable crop option, with the desirable flavour and aroma characteristics, i.e. bringing white crowberries to the countryside while maintaining the flavour of the beach!
... Fruit seeds have a thick and woody endocarp [3,5] and are rich in omega-3 and omega-6 polyunsaturated fatty acids (PUFAs), such as, alpha-linolenic (C18:3 n-3) and linoleic (C18:2 n-6), respectively [7,8]. Like other similar fruits, the C. album berry presents a high content in minerals and antioxidants, such as polyphenols [8][9][10], especially phenolic acids (e.g. chlorogenic acid, neochlorogenic acid, caffeic acid, p-hydroxybenzoic acid, pcoumaric acid and ferulic acid), flavonoids (e.g. ...
... delphinidin 3-O-hexoside, cyanidin 3-O-glucoside and cyanidin 3-Opentoside) [8,11]. Thus, this fruit pulp has shown to present several nutraceutical properties such as, to protect against diseases related to oxidative stress, prevent urinary infections, reduce the risk of cardiovascular disease, provide neuroprotection and contribute to the prevention of cancer [7,9,10,12]. Hence, given its composition, these berries can either be consumed as fresh or undergo processing, to produce lemonades, jams, appetizers, and liqueurs with acid flavours [1,7,9,11,13]. ...
Plants with one or more consumable parts are considered edible. Although many plants have been classified as edible (about 27 thousand species), few are used as food. Nonetheless, to overcome food scarcity and excessive dependence on the same plant species, humans have always consumed wild plants, either through direct intake, or as spices, condiments, or oils. Thus, edible wild plants are part of a cultural and genetic heritage assigned to different geographical areas, as well as important sources of essential oils, antioxidants, vitamins, minerals, and special flavours. Therefore, edible wild plants have been the subject of a growing interest, not only due to their nutritional and medicinal value, but also as a way of diversifying eating habits and of promoting biodiversity and ecological sustainability.
... [1][2][3] The fruits of C. album (L.) D. Don have been consumed in the Iberian Atlantic coast since the Islamic period (either fresh or in jams) and have been used in popular medicine as antipyretics and against pinworm infections. [2,4] In fact, they were found to contain flavonols, anthocyanins, and phenolic derivatives (mainly caffeic ester, benzoic, and chlorogenic acids), [3][4][5][6] which are responsible for a significant antioxidant capacity that confers them with interesting physiological properties, namely, as preventive agents against urinary infections, [7] cardiovascular and neurological disorders, [8][9][10][11] or cancer. [9,12,13] This antioxidant effect is suggested to be mediated by up-regulation of glutathione and cellular antioxidant enzymes, as well as by suppression of reactive oxygen species. ...
... [1][2][3] The fruits of C. album (L.) D. Don have been consumed in the Iberian Atlantic coast since the Islamic period (either fresh or in jams) and have been used in popular medicine as antipyretics and against pinworm infections. [2,4] In fact, they were found to contain flavonols, anthocyanins, and phenolic derivatives (mainly caffeic ester, benzoic, and chlorogenic acids), [3][4][5][6] which are responsible for a significant antioxidant capacity that confers them with interesting physiological properties, namely, as preventive agents against urinary infections, [7] cardiovascular and neurological disorders, [8][9][10][11] or cancer. [9,12,13] This antioxidant effect is suggested to be mediated by up-regulation of glutathione and cellular antioxidant enzymes, as well as by suppression of reactive oxygen species. ...
Corema album (L.) D. Don is a wild maritime shrub endemic to the Iberian Peninsula, which contains bioactive compounds with promising chemoprotective activity. The present work reports the first study of the edible fruits of this potentially health‐beneficial plant by complementary Raman and infrared techniques. Unique vibrational signatures were obtained for each part of the Corema album berries, revealing distinct chemical compositions for the skin (outer and inner) and the seeds, particularly regarding the content in phenolic derivatives, unsaturated fatty acids, and waxy polymers.
... Regarding the correlation between chemical composition and antioxidant capacity, it is worth noting that the massive content of hydroxycinnamic acids/hydroxycinnamates in B. grandiflora is enough to grant a remarkable antioxidant power, as we have previously reported in vitro and cell culture [17][18][19][20][21][22][23]. It is well known the correlation of the antioxidant activity of polyphenols with the number and position of -OH groups or the presence of a double bond in the position 2-3 of C ring in flavonoids. ...
Brunfelsia grandiflora is an ancient plant widely used for its promising medicinal properties, although little explored scientifically. Despite being a rich source of phenolic compounds responsible in part for the proven anti-inflammatory activity, its characterization has not been carried out to date. The present work deals with the exhaustive identification and quantification of its phenolic fraction, along with its antioxidant activity. Decoction resulting from the bark as fine powder was filtered and lyophilized, and polyphenols were extracted from the resulting product by aqueous-organic solvents. Seventy-nine polyphenols were identified using LC-MSn. Hydroxycinnamates was the most abundant group of compounds (up to 66.8%), followed by hydroxycoumarins (15.5%), lignans (6.1%), flavonols (5.7%), phenolic simples (3.1), gallates (2.3%), flavanols (0.3%), and flavanones (0.2%). About 64% of the characterized phenols were in their glycosylated forms. The quantification of these phytochemicals by LC-QToF showed that this medicinal plant contained 2014.71 mg of phenolic compounds in 100 g dry matter, which evidences a great antioxidant potency determined by ABTS and DPPH assays. Therefore, Brunfelsia grandiflora represents an important source of polyphenols which supports its therapeutic properties scientifically proven.
... HepG2 cells pre-treated with different extracts for 20 h (up to 40 µg/mL), before the oxidative insult (400 µM t-BOOH. for 3 h), showed reduced cell death, ROS content, GSH depletion, and oxidative damage in proteins and lipids (León-González et al., 2012). Identical results were reported for HepG2 cells pre-treated, for 3 h, with a functional juice rich in phenolic compound (26 % of juice grape, 2 % of cherry, 0.6 % of blackberry, 0.6 % of blackcurrant and 1 % of raspberry juice) which increased cell survival and decreased lipid peroxidation after exposure of cells to the pro-oxidants t-BOOH and H 2 O 2 (24 h) (García-Alonso, Ros, & Jesús Periago, 2006). ...
Despite the high value of Portuguese elderberries, recognized for decades by European markets, only a few studies address their beneficial effects at cellular level. Aiming to explore the anti-inflammatory and the cellular antioxidant potential characterized extracts from the three main Portuguese elderberry cultivars (Sabugueiro, Sabugueira, Bastardeira) were used. Lipopolysaccharide-stimulated RAW 264.7 cells pre-exposed to elderberry extracts exhibited dose-dependent inhibition of nitric oxide release, evidencing anti-inflammatory activity. Concerning cellular antioxidant protection, HepG2 and Caco-2 cells pre-exposure to elderberry extracts (50 µg/mL) prevented up-to 90% of tert-butyl hydroperoxide (t-BOOH)-induced toxicity. In Caco-2 cells, elderberry extracts prevented glutathione depletion, reactive oxygen species production, abnormal morphological changes and DNA fragmentation, in response to t-BOOH oxidative insult. Results demonstrated that elderberries have high potential in reducing cellular oxidative stress as well as in preventing inflammatory processes. Thus, elderberries have high potential as health promoters, acting as functional foods or as sources of nutraceuticals.
... Finally, it may be interesting to compare the presently obtained results with those from studies previously performed by other authors on C. album. In particular, León-González et al. [7] analyzed the phenolic content of the berries using different extraction methodologies. A large number of phenolic acids was identified by these authors (by HPLC and MS), in some cases reaching ca. ...
This study reports an evaluation of the biological properties of the edible berries from Corema album, an endemic shrub of the Portuguese coastline, aiming at its use as a nutraceutical. Different methanolic extracts were obtained from the pulp and seed of fresh berries: pulp extract, seed residue, and seed oil (extracted and characterized for the first time). For each of these, the antioxidant activity was assessed, by different methods, as well as the antimicrobial ability. Overall, the seeds were shown to be the most nutraceutical part of the berry since they showed higher antioxidant activity, while the pulp extract displayed a significant antimicrobial capacity against several clinically relevant bacterial strains. Furthermore, the extracts were fully characterized by complementary infrared and Raman spectroscopy, revealing the presence of phenolic acids, polysaccharides, sugars, and triterpenoids in the pulp, high content of unsaturated fatty acids in the seed oil, and significant amounts of phenolics and carotenoids in the seed residue. These results pave the way for a reliable correlation between chemical composition and biological activity, in edible fruit samples.
... C. album presents high levels of antioxidant activity that can be attributed to compounds such as phenolic compounds, mainly derivatives of chlorogenic acid and flavonols, including myricetin, rutin, kaempferol and hydroxycinnamic acids, p-coumaric, ferulic, caffeic, sinapinic acid derivatives, and anthocyanins [9,14]. The bioactive compounds present in berries have been associated to health benefits spanning from prevention of cardiovascular and neurodegenerative diseases (such as disorder of Parkinson's) to protection against oxidative stress, inflammation and cancer [14][15][16][17]. This evidence supports the traditional use of C. album in popular medicine as healthy fruits and suggests that the consumption of these berries could promote positive effects in human health and help to prevent chronic diseases. ...
This study investigated the knowledge and consumption habits related with white crow-berries ("camarinhas" in Portuguese) among the Portuguese population. It consisted of a questionnaire survey, undertaken on a sample of 501 participants, higher than 18 years old. For the treatment of data, basic descriptive statistics were used, complemented with the Mann-Whitney U test to assess some associations between categorical variables. Moreover, a tree classification analysis was carried out using a classification and regression tree (CRT) algorithm with cross-validation and a factor analysis was also used to treat the data. The results indicated that the majority of participants know the "camarinha" berry but the level of knowledge decreases from senior adults to young adults. On the other hand, the knowledge and overall perception about their nutritive value, senso-rial characteristics and health benefits are low. Regarding the consumption of crowberries, it was found that more than half of the participants did not eat them, and 31.9% ate them only around once a year, mainly fresh, being hand-harvested from the wild by the participants. Furthermore, it was observed that the Portuguese considered that the information about crowberries is scarce, which could justify that only a small part of the participants recognized this plant as vulnerable, due to loss of its habitat, mainly by human actions and owing to lack of information. To fill the gap of information observed in Portuguese people, it is hoped that the project (IDEAS4life) that supports this work could contribute to increase the knowledge about this species and also to alert for the need of preserving this endogenous plant of the Southern European Atlantic coast.
... As previously mentioned, several studies reported high contents of phenolics in C. album fruits: 12 mg GAE/g (dw) (Pimpão et al. 2013); 1214.4 ± 122 mg GAE/kg (fw) and 7316.6 ± 740 mg GAE/kg (dw) (Léon- González et al. 2013); 1997 ± 75 mg GAE/ 100 g (Andrade et al. 2017a) and 1393.91 ± 0.06 mg/ 100 g characterised in a water extract (Léon- González et al. 2012). These studies agree on the high antioxidant potential of the C. album fruits, attributed to the phenolic composition which supports our results. ...
There is a growing interest in Corema album (L.) D. Don fruits due to the unique white colour, mildly acidic lemony flavour and health-promoting properties associated with its bioactive composition. This study performs a physical–chemical characterisation of cultivated C. album fruits from a multi-origin clonal field. The field comprises ten wild populations with distinct geographical origins, grown under the same edaphoclimatic conditions. We analysed fruits CIELab colour parameters, texture profile (TPA), pH, acidity (TA, g.100 mL⁻¹), soluble solids content (SSC, %) and total phenolic content (TPC, mg CAE.100 g⁻¹). Our results showed differences between fruits physical–chemical attributes. Variation patterns in fruits SSC and hardness suggest that the differences might be related to the original geographical location of the populations. The determined TPC levels in all samples were very encouraging at a bioactive level, ranging from 185.3 to 355.6 mg CAE.100 g⁻¹. Fruits from Mira and Pego populations stood out from the ten geographical provenances. Mira fruit samples had higher sweetness and lower acidity, while the Pego ones had firmer fruits and higher phenolic content. The multi-origin clonal field allowed us to offer an interesting scientific comparative background, highlighting the large potential of these berries for introduction in the commercial market. Not only our results support the potential of white crowberry as a new crop; the detected differences also indicate a hidden capacity for small fruit market diversification.
... The white fruits have been chemically characterized. C. album berry phenolic extracts were found to be rich in hydroxycinnamic acids, and promising results regarding biological effects on the treatment of liver cells were found while related to the improvement of both redox condition and protection against oxidative stress [4]. ...
Increasing interest in Corema album L. is raising due to the appealing white colour and potential health benefits related to its bioactive composition. White fruits production culminates in late August on coastal dunes, but fruits of various colours are present almost till flowering (late February). We undertook a preliminary physical-chemical characterisation (biometric, CIELab colour, pH, soluble solids content and titrable acidity) of a late fruit collection to disentangle maturity progression and to reveal latent qualities for future utilisation. Irrespective of fruit perceived colouration (white, translucent, brown, brown with black spots and black), the characterized high acidity (1-3 g.100 mL-1) is suggestive that over-mature fruits can still be further explored as food additives. Moreover, using a multivariate exploratory technique, we found a clear fruit's maturation progression from white/translucent to black, a so-far unreported maturity stage. Addressing gaps in plant phenology and fruit's maturity behaviour is needed before undertaking cultivation.
... The AOA of the samples analysed was considerable, ranging from 25 to 42 μmol TE/g when determined by the DPPH method and from 52 to 80 μmol TE/g when determined by the ABTS method. According to León-González et al. [6], C. album extracts possess antioxidant effect against reactive oxygen species (ROS) and anticarcinogenic potential as demonstrated in cell cultures. The antioxidant capacity of some bioactive molecules is very important, but its effect is very variable according to some factors that diminish its bioaccessibility along the digestive system. ...
This work aimed at evaluating bioactive compounds with antioxidant activity in Corema album berries. The phenolic properties were evaluated in different extracts from lyophilized samples of pulp and seeds, namely total phenolic compounds, ortho-diphenols, flavonoids, tannins and antioxidant activity by DPPH and ABTS methods. Furthermore, this study also aimed to assess the bioaccessibility of total phenolic compounds and their antioxidant activity through an in vitro simulation of the different stages of the gastrointestinal tract. The results showed high contents of total phenolic compounds (463–1614 mg GAE/100 g), of ortho-diphenols (11–23 mg GAE/100 g), of flavonoids (324–1437 mg QE/100 g) and of tannins (267–871 mg/100 g). The antioxidant activity varied in the ranges 25–42 and 52–80 μmol TE/g, respectively for DPPH and ABTS methods. Through the evaluation of bioaccessibility it was found that a high percentage of the total phenolics was lost so that only about 13–36% remained available for absorption, although there was a better preservation of the antioxidant activity, 18–49%, depending on the sample and extracting solution.
... Topoisomerase II, a nuclear enzyme that regulates DNA metabolism and one of the targets in the development of drugs against cancer, is inhibited in vitro by yerba mate (Gonzalez de Mejia et al., 2005). Data on ROS production when cancer cells were incubated with YME and when normal cells were incubated with both YME or its CQA derivatives confirmed our previous results with 5-CQA, 3,5DCQA ( Baeza et al., 2014), DHCA and DHFA ( Baeza et al., 2016a) or other herbal extracts which contain these phenolic compounds such as green coffee ( Baeza et al., 2014) and Corema album extracts (Le on Gonz alez et al., 2012). The antioxidant activity might therefore contribute to reduce the oxidative stress associated with cancer initiation and progression. ...
This work aimed at studying the effects of green coffee bean (GCBE) and yerba mate (YME) extracts, their main phenolic components (5-caffeoylquinic acid, 5-CQA; 3,5-dicaffeoylquinic acid, 3,5-DCQA) and metabolites (ferulic acid, FA; caffeic acid, CA; dihydrocaffeic acid, DHCA; and dihydroferulic acid, DHFA) along with caffeine (CAF) on the viability and proliferation of different human cell lines. Extracts (10-1000 μg/mL) and standards (10-1000 μM) were assayed in colon (Caco-2), lung (A549), oesophageal (OE-33), urinary bladder (T24) human carcinoma cells, and a non-cancer cell line (CCD-18Co). YME significantly reduced viability of cancer cells at all assayed concentrations, the higher doses also reducing cell proliferation. GCBE effects on cell viability were more effective at 100 and 1000 μg/mL, showing modest effects on cell proliferation. The highest doses of 5-CQA and 3,5-DCQA reduced cell viability and proliferation in all cell lines, whereas FA, DHCA and DHFA had lower and variable effects. Caffeine had no effect. Dietary-attainable concentrations (0.1, 1 and 10 μg/mL) of YME were tested for cytotoxicity and reactive oxygen species generation, showing no cytotoxic effect. Low concentrations of all tested compounds were non-cytotoxic to CCD-18Co cells.
Conclusion:
YME and to a lower degree GCBE, their phenolic components and metabolites may decrease cancer cell viability and proliferation.
... Topoisomerase II, a nuclear enzyme that regulates DNA metabolism and one of the targets in the development of drugs against cancer, is inhibited in vitro by yerba mate (Gonzalez de Mejia et al., 2005). Data on ROS production when cancer cells were incubated with YME and when normal cells were incubated with both YME or its CQA derivatives confirmed our previous results with 5-CQA, 3,5DCQA ( Baeza et al., 2014), DHCA and DHFA ( Baeza et al., 2016a) or other herbal extracts which contain these phenolic compounds such as green coffee ( Baeza et al., 2014) and Corema album extracts (Le on Gonz alez et al., 2012). The antioxidant activity might therefore contribute to reduce the oxidative stress associated with cancer initiation and progression. ...
Red grape pomace (RGP) is a major winery by-product with interesting applications due to its high phenolic content and antioxidant capacity. Effects of in vitro gastrointestinal digestion and storage on the phenolic content and antioxidant capacity of RGP were studied. RGP polyphenols were stable under stomach-mimicking conditions and more sensitive to small intestine conditions, reducing anthocyanins and flavonols. After 3- and 6-month storage, at either 4 or 25 °C, there were no changes in the total phenolic and condensed tannin content, or antioxidant capacity (evaluated by ABTS, FRAP, ORAC assays); however, after 9 months these parameters decreased. Contrarily, chromatic b* values were higher, thus the samples had more intense red color, which may be related to the increased condensed tannin content. Storage time or temperature induced no changes in microbiological load. RGP preserves high antioxidant capacity after storage and in vitro digestion and thus presents potential as a functional ingredient or nutraceutical.
... A high and significant increase in glutathione levels and the HDL/LDL risk factor was found in rats submitted to CCL4-induced liver fibrosis and necrosis which had been treated with an S. marianum extract [16], or rats with N-nitrosodimethylaminethe-induced degenerative hepatic changes treated with 100 mg/kg b. w. silibinin [21]. Additionally, other studies have reported comparable recoveries of GSH with antioxidant extracts from the wild berry Corema album [22], cocoa [18], green coffee [23], and cranberry [24] in different cell types submitted to oxidative stress. GSH is the main nonenzymatic antioxidant defense as a substrate in glutathione peroxidase-catalyzed detoxification of organic peroxides by reacting with free radicals and by repairing free radical-induced damage through electron transfer reactions. ...
Silybum marianum Gaertn. (Milk thistle) has been used since ancient times for the relief of liver diseases characterized by intense oxidative stress such as inflammatory liver disease and cirrhosis. As oxidative stress by hyperglycemia is involved in micro- and macrovascular complications of type 2 diabetes, our aim was to assess the protective effect of milk thistle seed extract against oxidative stress induced by a high glucose concentration on endothelial cells (EA.hy926 cells). High-performance liquid chromatographic analysis shows flavonolignans silychristin and silibinin A and B as major components. No cell toxicity was observed for concentrations up to 100 µg/mL of milk thistle extract for 24 h. Concentrations of 5-25 µg/mL of the extract were used to assess the protective effect on EA.hy926 cells treated with 30 mM glucose for 24 h. Oxidative damage by 30 mM glucose was shown as a significant decrease in reduced glutathione and a significant increase in protein carbonyls and antioxidant enzyme activities. S. marianum extract recovered reduced glutathione and balanced the elevated carbonyls and enzyme activity. Silibinin alone also recovered reduced glutathione and antioxidant enzymes. S. marianum protects endothelial cell against oxidative damage by modulating antioxidant enzyme activity, reduced glutathione, and protein carbonyl levels.
Georg Thieme Verlag KG Stuttgart · New York.
... Other authors have reported similar effects of phenolic extracts from plants rich in monocaffeoylquinic acids such as Hemerocallis fulva (Lin, Lu, Huang, & Chen, 2011) and Corema album (León-González et al., 2012), or rich in dicaffeoylquinic acids like Gymnaster koraiensis (Jho et al., 2013) decreasing ROS generation in HepG2 cells, partially preventing the GSH depletion, antioxidant enzyme dysregulation and oxidative damage to macromolecules induced by t-BOOH, in line with the effects elicited by the YMPE. ...
The hepatoprotective effect of a yerba mate phenolic extract (YMPE), rich in chlorogenic acids, and its main circulating metabolites dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids were assessed in human hepatoma HepG2 cells subjected to oxidative damage induced by tert-butylhydroperoxide (t-BOOH). Direct treatment of HepG2 cells with realistic concentrations of YMPE (1, 10 and 50 μg/mL), DHCA or DHFA (0.2, 1, 10 μM) for 20 h was not cytotoxic and significantly decreased ROS generation. Pre-treatment with YMPE and DHCA prevented the cytotoxicity and macromolecular damage induced by t-BOOH. Moreover, decreased levels of reduced glutathione (GSH), and increased ROS levels and antioxidant enzyme activity induced by t-BOOH were dose-dependently recovered. DHFA only showed a slight protection against cell cytotoxicity, lipid oxidation and GSH depletion. In conclusion, YMPE and one of its major microbial metabolites, DHCA, confer significant protection against oxidative damage, adding evidences to the beneficial health effects associated with mate intake.
... Moreover, it has been shown that the protective effect exerted by quercetin and catechin against the oxidative damage induced by hydrogen peroxide in BL-9 line rat hepatocytes, is mediated by the induction of the enzyme GPx [37]. Leon-Gonzalez et al. observed that polyphenol-rich extracts derived from Corema album berry fruits are able to reduce the oxidative damage induced by tertbutylhydroperoxide (t-BOOH) in HepG2 human hepatocarcinoma cells, and that this chemo-protective activity involves increasing cellular levels of reduced glutathione (GSH) [38]. Martin et al. also described an increased activity of GPx and GT in HepG2 cells in response to a cocoa extract rich in flavonoids [39]. ...
Reactive oxygen species (ROS) play a major role in carcinogenesis: pro-oxidant agents like tobacco smoke, asbestos or N-nitrosamines, are known as mutagenic and carcinogenic, and cancer cells show increased levels of ROS and redox deregulation. However, pro-oxidant molecules can also act as selective cytotoxic agents against cancer cells by achieving toxic levels of ROS. Although polyphenols are well-known as potent antioxidants, a pro-oxidant effect has been associated with their pro-apoptotic effect in various types of tumor cells. The aim of the present review is to present the main evidences of the pro-oxidant-related cytotoxic activity of naturally occurring polyphenols and their underlying mechanisms.
Copyright © 2015. Published by Elsevier Inc.
... The UV spectra of this type of compounds is general characterized by similar maxima at 230-240 nm, 320-330 nm and a shoulder at 290-300 nm (Gouveia & Castilho, 2011 Lin and Harnly (2008) and Gouveia and Castilho (2012) 3,4-diCQA, 3,5-diCQA and 4,5-diCQA have been identified in AST extract by our previous research, and the detailed fragmentation pattern of diCQA was also depicted (Zhang et al., 2014). One caffeic acid (peak 48), one caffeic acid-hexoside (peak 12) and one caffeic acid-glucuronide (peak 34) were proposed by elucidating and comparing the MS and MS 2 spectra with literature (León-González et al., 2012 ...
This study aimed to evaluate the antioxidant potential of Artemisia selengensis Turcz (AST) leaves, a byproduct when processing AST stalk, and identify the antioxidant constituents by using HPLC-QTOF-MS(2). The total phenolics content (TPC), total flavonoids content (TFC) and antioxidant abilities of fractions resulted from the successively partition of chloroform, ethyl acetate and n-butanol were compared. Ethyl acetate fraction (EAF) exhibited the highest TFC (65.44mgQuE/gfraction), n-butanol fraction (nBuF) showed the highest TPC (384.78mgGAE/gfraction) and the best DPPH scavenging ability, ABTS(+) scavenging ability and reducing power. Totally, 57 compounds were identified or tentatively identified in nBuF and EAF, 40 of them were reported in AST for the first time. The major constituents in EAF were flavonoids, and the major constituents in nBuF were phenolic acids and organic acids. Thus, AST leaves might be a potential low-cost resource of natural antioxidants.
Copyright © 2015 Elsevier Ltd. All rights reserved.
... Similar results preventing ROS generation induced by t-BOOH or tumor necrosis factor α (TNF-α) were seen when treating HepG2 cells with Hemerocallis fulva flower extracts (Lin, Lu, Huang, & Chen, 2011) and Gymnaster koraiensis extracts (Jho et al., 2013) rich in mono-and dicaffeoylquinic acids, respectively. The results here reported are also in agreement with previous studies on HepG2 and other cell lines with cocoa phenolic extract (Martin et al., 2008), hydroxycinnamic acids (Cho et al., 2009;Granado-Serrano et al., 2007;León-Gónzalez et al., 2012;Zha, Xu, Wang, Dong, & Wang, 2007), hydroxytyrosol (Pereira-Caro et al., 2012), lutein (Lima et al., 2007), quercetin (Alía, Ramos, Mateos, Granado-Serrano, Bravo and Goya, 2006), epicatechin or procyanidin B2 (Rodríguez-Ramiro et al., 2011). Choi et al. (2005) also showed a hepatic-protective role for 3,4dicaffeoylquinic acid (3,5-DCQA isomer) against carbon tetrachloride induced hepatic cytotoxicity, improving aminotransferases and bilirubin levels. ...
The intake of green coffee has been associated with a lower risk of diseases of oxidative etiology probably due to its high phenolic content. The present study investigated the effect of treating human HepG2 cells with different concentrations of a green coffee bean extract (GCBE) and its main hydroxycinnamic acids, 5-caffeoylquinic acid (5-CQA) and 3,5-dicaffeoylquinic add (3,5-DCQA), and the methylxanthine caffeine (CAF), directly or prior to inducing an oxidative stress by incubating cells with 400 mu M tert-butylhydroperoxide (t-BOOH). Direct treatment with GCBE (1-50 mu g/mL), 5-CQA and 3,5-DCQA (1-40 mu M) significantly decreased reactive oxygen species (ROS) production by HepG2 cells. Pre-treatment with GCBE, 5-CQA and 3,5-DCQA for 20 h prevented the cellular and macromolecular damage induced by t-BOOH, returning glutathione levels and the activity of antioxidant enzymes to values similar to control cells. Moreover, the increased ROS generation induced by t-BOOH was dose-dependently prevented when cells were pre-treated with GCBE, 5-CQA and 3,5-DCQA. CAF showed no protective effect. It can be concluded that GCBE and its main polyphenols, 5-CQA and 3,5-DCQA, but not caffeine, confer a significant protection against oxidative stress in vitro.
... Their acidic, tasty fruits are spherical, white berries which are consumed as appetizers, juices or used in folk medicine. We have recently reported a high content of phenolic compounds, mainly phenolic acids, and in vitro antioxidant properties of C. album berries [2,3], and we have recently isolated cytotoxic dihydrochalcones from the EtOAc extract of the leaves [4]. Therefore, continuing the study of this plant, we have looked for other cytotoxic compounds from the leaves of this species and their mechanism of action on HCT116 and HT29 colon cancer cell lines. ...
The leaves of Corema album (Ericaceae), an endemic shrub which grows in Atlantic coastal areas of the Iberian Peninsula, are rich in flavonoids and other secondary metabolites. Silica gel column chromatography of the ethyl acetate extract from dried leaves was performed and a flavonic active fraction was obtained. The cytotoxic activity of this fraction was assessed using the colon cancer cell lines HCT116 and HT29. After 48 hours of treatment, cell viability was determined with luminescence-based ATPLite assay, showing IC50 values of 7.2 +/- 0.7 and 6.8 +/- 1.2 microg/mL, respectively. The study by flow cytometry revealed that the cytotoxicity of this fraction was mediated, at least in part, by induction of apoptosis and G2/M cell cycle arrest. The active fraction was then subjected to Sephadex LH-20 chromatography and two flavonoids were separated and identified as the flavanone pinocembrin and 2',4'-dihydroxychalcone after UV, MS and NMR analysis.
Corema (C.) album is a shrub endemic to the Atlantic coast and has been described as yielding beneficial effects for human health. Nevertheless, studies concerning the bioactivity of C. album leaves are scarce. This study aims at investigating the anticancer potential and mode of action, of an hydroethanolic extract of C. album leaves (ECAL) on triple-negative breast cancer. This is a poor survival breast cancer subtype, owing to its high risk of distant reappearance, metastasis rates and the probability of relapse. The ECAL ability to prevent tumor progression through (i) the inhibition of cell proliferation (cell viability); (ii) the induction of apoptosis (morphological changes, TUNEL assay, caspase-3 cleaved) and (iii) the induction of DNA damage (PARP1 and γH2AX) with (iv) the involvement of NF-κB and of ERK1/2 pathways (AlphaScreen assay) was evaluated. ECAL activated the apoptotic pathway (through caspase-3) along with the inhibition of ERK and NF-κB pathways causing DNA damage and cell death. The large polyphenolic content of ECAL was presumed to be accountable for these effects. The extract of C. album leaves can target multiple pathways and, thus, can block more than one possible means of disease progression, evidencing the anticancer therapeutic potential from a plant source.
Over the past years, several studies have also reported the adverse effects of hyperthermia on normal testicular tissues in several species including mice, rats, and humans. These deleterious impacts include temporarily drop in relative weight of testis along with a temporary partial or complete infertility. Sambucus nigra, also known as elderberry or sweet elder, is a source of bioactive compounds that has drawn growing attention for its potential beneficial effects in preventing and treating several diseases. This experimental research divided 30 mice into the following three groups: (1) control, (2) hyperthermia, and (3) hyperthermia receiving elderberry diet for 35 days. Scrotal hyperthermia was induced by water bath with 43 °C for 30 min. Then, the mice were euthanized, and their sperm samples were collected for sperm parameters analysis. Then, we took the testis samples for histopathological experimentations, immunohistochemistry against TNF-α and caspase-3 and serum testosterone, FSH and LH levels. Our outputs indicated that elderberry diet could largely improve the sperms parameters and stereological parameters, like spermatogonia, primary spermatocyte, round spermatid, and Leydig cells together with an increasing level of the serum testosterone compared to the scrotal hyperthermia induced mice. In addition, it was found that the expression of TNF-α and caspase-3 significantly decreased in the treatment groups by elderberry diet compared to the scrotal hyperthermia-induced mice. In conclusion, it could be concluded that elderberry diet may be regarded as an alternative treatment for improving the spermatogenesis process in the scrotal hyperthermia induced mice.
Corema album (L.) D. Don (Ericaceae) is an endemic bush that grows along the Atlantic littoral of the Iberian Peninsula. Its edible white berries (known as camarinas, camariñas, camarinhas, white crowberry, among other vernacular names) have been used in popular medicine as an antipyretic and are consumed in localised areas of Portugal and Spain as appetisers and in the preparation of juices and jams. The aim of the present review is to summarise the knowledge of the chemical composition and pharmacological studies performed with C. album fruit and extracts. These berries are rich in phenolic compounds, including phenolic acids, stilbenes, flavonols, flavanones, prenylated flavanone, flavanols, and anthocyanins. The total phenolic content of various extracts of the pulp of these berries has been positively correlated with their antioxidant capacity. In this respect, the treatment with acetone, ethyl acetate, and aqueous extracts of this fruit has protected HepG2 cells against chemically induced oxidative stress. The chemoprotective effect of these extracts is mediated by preventing reactive oxygen species formation, reduced glutathione depletion, antioxidant enzyme over-activity, and oxidative damage to proteins and lipids. Furthermore, the presence of pentacyclic triterpenes, such as ursolic and oleanolic acids, in C. album berries confers reflectance UV properties to this fruit and derived extracts. In short, existing studies suggest that the development of C. album crops should be considered as a promising opportunity to obtain these remarkable berries. Moreover, further experiments should also be designed to evaluate their in vivo effect and to ascertain the underlying mechanism of action.
Corema album is one of the two species of flowering plants in the Corema genus, from family Ericaceae, and is also known for its common name Camarinha or Portuguese crowberry. It has a restricted distribution, being confined to the western Atlantic coast of the Iberian Peninsula and Aquitaine in France, in dune systems or in low pine forests. The shrub is exploited because of its food, ornamental and medicinal value and the regeneration rate in the natural habitat is very low. For the first time, an in vitro propagation protocol has been developed from nodal segments obtained from adult plants in the field. Several nutrient formulations were tested for the establishment and the best results, in terms of highest bud break frequency (6.7%), were achieved with the woody plant medium (WPM) basal salts, supplemented with 2.0 mg l⁻¹ 2iP at pH 5.6. WPM was then used for sub-culturing of shoots every 8 weeks and to perform an assay to test the effect of different cytokinins (BA, Kin 2iP and mT) combinations in the multiplication phase. Of all the combinations tested, 2.0 mg l⁻¹ 2iP with 1.0 mg l⁻¹ Kin is the most beneficial with 100% bud break, 6.8 new shoots, with 14.2 mm average length and the shoots regenerated were healthy. A study with a temporary immersion bioreactor (SETIS™) was performed, with promises results, where more than double the multiplication rate was achieved compared with the previous semisolid medium. However, in this system, vitrification processes have occurred which may compromise the viability of the shoots. Rooting, which proved to be a difficult process, was best induced ex vitro by dipping of the microshoots in a 2.0 g l⁻¹ IBA solution for 10 s, followed by placement in jiffy-7C pellets, with 20% of rooting and an average of 5.3 roots and 43.8 mm long. The microplants were potted and acclimatized, showed 100% survival.
Information about plant gathering by Palaeolithic hunter-gatherers in Europe is scarce because of the
problems of preservation of plant remains in archaeological sites and due to the lack of application of
archaebotanical analysis in many of them. Botanical macroremains ewood charcoal, seeds, fruits, leaves,
etc. - provide information not only about palaeoeconomy of hunter-gatherers, but also about climate,
landscape and vegetation dynamics.
In Gravettian and Solutrean levels of Cova de les Cendres (Alicante, Spain), Corema album pyrenes
(Empetraceae or crowberries family) have been identified. On the contrary, wood charcoal of this species
has not been documented among the remains of firewood. This differential presence of plant organs,
together with the nutritional value of its fruits, which is presented here, make us hypothesize the systematic
gathering of C. album fruits for human consumption. They have a high content in vitamin C, as
well as potassium, magnesium and copper.
Corema album (camari~na) is a unique species, nowadays in danger of extinction. Its main population is
located on the Atlantic coast of Iberian Peninsula, but in 1996 a small population was discovered on the
Mediterranean Iberian coast (Benidorm, Spain). Archaeobotanical data from Cova de les Cendres (Teulada-
Moraira, Spain) presented here point to a larger population of camari~na during Upper Palaeolithic
on the coast of Alicante. The harsh climatic conditions of the Last Glacial Maximum during Solutrean
period, with colder temperatures and aridity increase, could explain the reduction of the presence of
C. album remains until its absence in Magdalenian. The climatic amelioration during Upper Magdalenian
did not mean the recovery of camari~na population in the Moraira headland area. Probably, the rising of
the sea level would affect them destroying its dune habitat.
The main phenol in mate and coffee, 5-caffeoylquinic-acid (5-CQA), and its relevant microbial metabolites, dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids, have shown oxidative-stress protective effects in HepG2 cells. To evaluate possible endothelial-protective effects of the extracts and compounds, endothelial EA.hy926 cells were pre-treated with yerba mate (YME) and green coffee bean (GCBE) phenolic extracts, 5-CQA, DHCA and DHFA and afterwards stressed with tumour-necrosis-factor-alpha (TNF-α). Then oxidative-stress markers and endothelial-nitric-oxide-synthase levels were studied. TNF-α (10 ng/mL, 24 h) depleted reduced glutathione (GSH) and eNOS levels, increased reactive oxygen species (ROS) production, glutathione peroxidase (GPx) and reductase (GR) activities, and protein oxidation (carbonyl groups, CG) in EA.hy926 cells. Pre-treatment with YME, GCBE, 5-CQA, DHCA at certain physiological concentrations, lowered ROS production, recovered depleted GSH, reduced GR and GPx activities, and CG levels, and enhanced eNOS concentration.. YME, GCBE and 5-CQA show antioxidant effects in endothelial cells playing DHCA an important role in such protection; moreover, the extracts, 5-CQA, DHCA and DHFA increased eNOS levels.
Oxidative stress is a key process in several diseases and a growing body of preclinical/clinical evidence has pushed forward the health benefits of (poly)phenols. The protective potential of Corema album and Arbutus unedo (Poly)phenol Digested Metabolites (PDM), generated after in vitro digestion was evaluated. Chemical alterations caused by the digestion led to alterations of compounds reactivity. A. unedo leaf PDM arose as the fraction conferring the highest protective activity to the wild type and oxidative stress-sensitive yap1 yeast strains challenged with H 2 O 2. Our mechanistic studies disclosed the effect of A. unedo leaf PDM on cell redox homeostasis and mitochondrial function, and identified HAP4, SOD1, SOD2, GSH1 and GLR1 as mediators of cellular protection. Also, RPN4-and ATG8-associated protein clearance pathways were revealed as putative targets. Overall, these data suggest the nutraceutical potential of A. unedo leaf PDM as a functional food for human health.
Oxidative stress and reactive oxygen species (ROS)-mediated cell damage are implicated in various chronic pathologies. Emerging studies show that polyphenols may act by increasing endogenous antioxidant defense potential. Cranberry has one of the highest polyphenol content among commonly consumed fruits. In this study, the hepato-protective activity of a cranberry juice (CJ) and cranberry extract (CE) powders against oxidative stress was screened using HepG2 cells, looking at ROS production, intracellular non-enzymatic and enzymatic antioxidant defenses by reduced glutathione concentration (GSH), glutathione peroxidase (GPx) and glutathione reductase (GR) activity and lipid peroxidation biomarker malondialdehyde (MDA). Involvement of major protein kinase signaling pathways was also evaluated. Both powders in basal conditions did not affect cell viability but decreased ROS production and increased GPx activity, conditions that may place the cells in favorable conditions against oxidative stress. Powder pre-treatment of HepG2 cells for 20 h significantly reduced cell damage induced by 400 μM tert-butylhydroperoxide (t-BOOH) for 2 h. Both powders (5–50 μg/ml) reduced t-BOOH-induced increase of MDA by 20% (CJ) and 25% (CE), and significantly reduced over-activated GPx and GR. CE, with a significantly higher amount of polyphenols than CJ, prevented a reduction in GSH and significantly reduced ROS production. CJ reversed the t-BOOH-induced increase in phospho-c-Jun N-terminal kinase. This study demonstrates that cranberry polyphenols may help protect liver cells against oxidative insult by modulating GSH concentration, ROS and MDA generation, antioxidant enzyme activity and cell signaling pathways.
Diabetes mellitus is associated with reductions in glutathione, supporting the critical role of oxidative stress in its pathogenesis. Antioxidant food components such as flavonoids have a protective role against oxidative stress-induced degenerative and age-related diseases. Flavonoids constitute an important part of the human diet; they can be found in most plant foods, including green tea, grapes or cocoa and possess multiple biological activities. This article summarizes the latest results obtained with a cocoa phenolic extract (CPE) and its main flavonoid component epicatechin (EC) in cell culture models of beta cells and hepatocytes. The effect of CPE and EC on cell integrity and redox status and their chemo-protective capacity against an oxidative stress induced by tert-butylhydroperoxide (t-BOOH) were tested on pancreatic beta cells as well as cell viability and first elements of the insulin signaling pathway were evaluated in hepatocytes. Doses of 1-20 mu g/mL CPE and 1-20 mu M EC, considered realistic, evoked no damage and preserved the redox status of cultured beta cells and hepatocytes. Treatment of beta cells with CPE/EC significantly prevented the t-BOOH-induced oxidative damage. Besides, treatment of hepatocytes with CPE/EC increased responsiveness to insulin and decreased glucose production. Thus, CPE and EC show favorable effects against a diabetic condition both in pancreatic and hepatic cells.
In this work we investigated the in vivo protective effects of Baccharis dracunculifolia leaves extract (BdE) against carbon tetrachloride (CCl4)- and acetaminophen (APAP)-induced hepatotoxicity. Total phenolic content, total flavonoid content, antioxidant DPPH radical scavenging activity, and HPLC analysis were performed. Our results showed that pretreatment with BdE significantly reduced the damage caused by CCl4 and APAP on the serum markers of hepatic injury, AST, ALT, and ALP. Results were confirmed by histopathological analysis. Phytochemical analysis, performed by HPLC, showed that BdE was rich in p-coumaric acid derivatives, caffeoylquinic acids and flavonoids. BdE also showed DPPH antioxidant activity (EC50 of 15.75 ± 0.43 μg/mL), and high total phenolic (142.90 ± 0.77 mg GAE/g) and flavonoid (51.47 ± 0.60 mg RE/g) contents. This study indicated that B. dracunculifolia leaves extract has relevant in vivo hepatoprotective properties.
Aqueous pomegranate seed extract (PSE), a by-product of the pomegranate juice industry, was recently identified as a potential antiglycative ingredient. Ellagic acid was proposed as the major polyphenol responsible for the antiglycative activity as exerted in in vitro models. However, there is no information on safety aspects of this extract in biological systems before its application as ingredient. The cytotoxicity of PSE (1-100 µg mL(-1) ) was evaluated by determining its effect on cell viability and redox status of cultured HepG2 cells. The protective effect of the PSE against oxidative stress induced by tert-butyl hydroperoxide (t-BOOH) was also investigated.
No changes in cell integrity or intrinsic antioxidant status resulted from a direct treatment with aqueous PSE, even at high dosage. In addition, reactive oxygen species (ROS) induced by t-BOOH were reduced by 21% when cells were pretreated with 100 µg mL(-1) of aqueous PSE at 180 min. The range of concentrations investigated was effective in decreasing the ROS formation but not in a dose-dependent manner.
Aqueous pomegranate seed extract enhances human hepatoma cells integrity and resistance to cope with a stressful situation at concentration up to 100 µg mL(-1) . © 2013 Society of Chemical Industry.
During our search for cytotoxic compounds from Andalusian vascular plants, the ethyl acetate extract from the leaves of Corema album (L.) D. Don (Ericaceae) was selected for its cytotoxic activity against the HT-29 human colon adenocarcinoma cell line. Two dihydrochalcones, 2',4'-dihydroxydihydrochalcone (1) and 2'-methoxy-4'-hydroxydihydrochalcone (2), have been isolated from the leaves of C. album. Their structural identification was based on 1H NMR and 13C NMR data, including 2D NMR, and mass spectrometry. These compounds were subjected to the sulfhorhodamine B (SRB) cytotoxic assay against human colon adenocarcinoma cells (HT-29). Compounds 1 and 2 showed higher cytotoxicity than the positive control 5-fluorouracil (5-FU); the IC50 values (microM +/- SEM) were 1.8 +/- 0.4 for compound 1, 8.5 +/- 2.1 microM for compound 2, and 8.7 +/- 4.0 for 5-FU. The cytotoxic activity of 1 and 2 was reduced in the presence of the antioxidants N-acetylcysteine (NAC) and Mn(III) Tetrakis(1-methyl-4-pyridyl) porphyrin pentachloride (MnTMPyP), therefore suggesting that reactive oxygen species generation participates in the cytotoxic activity of these dihydrochalcones.
Phenolic compounds are secondary metabolites generally involved in plant adaptation to environmental stress conditions. Chlorogenic acids (CGA) and related compounds are the main components of the phenolic fraction of green coffee beans, reaching levels up to 14 % (dry matter basis). These compounds have a number of beneficial health properties related to their potent antioxidant activity as well as hepatoprotective, hypoglycemic and antiviral activities. The main groups of CGA found in green coffee beans include caffeoylquinic acids, dicaffeoylquinic acids, feruloylquinic acids, p-coumaroylquinic acids and mixed diesters of caffeic and ferulic acids with quinic acid, each group with at least three isomers. During coffee processing, CGA may be isomerized, hydrolyzed or degraded into low molecular weight compounds. The high temperatures of roasting also produce transformation of part of CGA into quinolactones and, along with other compounds, melanoidins. This review focuses on the chemical characteristics, biosynthesis, and distribution of CGA and related compounds in coffee. The influence of genetic, physiological and environmental factors as well as processing on the chemical composition of coffee beans is discussed. The impact of CGA composition of green coffee on cup quality is also approached. Despite the existence of substantial published information on the total levels of CGA in coffee, more research is needed on the composition of minor phenolic compounds and specific CGA isomers (and related substances) in green and roasted coffee beans, as well as their impact on coffee quality.
Lipid peroxidation products like malondialdehyde, 4-hydroxynonenal and F(2)-isoprostanes are widely used as markers of oxidative stress in vitro and in vivo. This study reports the results of a multi-laboratory validation study by COST Action B35 to assess inter-laboratory and intra-laboratory variation in the measurement of lipid peroxidation. Human plasma samples were exposed to UVA irradiation at different doses (0, 15 J, 20 J), encoded and shipped to 15 laboratories, where analyses of malondialdehyde, 4-hydroxynonenal and isoprostanes were conducted. The results demonstrate a low within-day-variation and a good correlation of results observed on two different days. However, high coefficients of variation were observed between the laboratories. Malondialdehyde determined by HPLC was found to be the most sensitive and reproducible lipid peroxidation product in plasma upon UVA treatment. It is concluded that measurement of malondialdehyde by HPLC has good analytical validity for inter-laboratory studies on lipid peroxidation in human EDTA-plasma samples, although it is acknowledged that this may not translate to biological validity.
Human subjects drank coffee containing 412 mumol of chlorogenic acids, and plasma and urine were collected 0 to 24 h after ingestion and were analyzed by high-performance liquid chromatography-mass spectrometry. Within 1 h, some of the components in the coffee reached nanomole peak plasma concentrations (C(max)), whereas chlorogenic acid metabolites, including caffeic acid-3-O-sulfate and ferulic acid-4-O-sulfate and sulfates of 3- and 4-caffeoylquinic acid lactones, had higher C(max) values. The short time to reach C(max) (T(max)) indicates absorption of these compounds in the small intestine. In contrast, dihydroferulic acid, its 4-O-sulfate, and dihydrocaffeic acid-3-O-sulfate exhibited much higher C(max) values (145-385 nM) with T(max) values in excess of 4 h, indicating absorption in the large intestine and the probable involvement of catabolism by colonic bacteria. These three compounds, along with ferulic acid-4-O-sulfate and dihydroferulic acid-4-O-glucuronide, were also major components to be excreted in urine (8.4-37.1 mumol) after coffee intake. Feruloylglycine, which is not detected in plasma, was also a major urinary component (20.7 mumol excreted). Other compounds, not accumulating in plasma but excreted in smaller quantities, included the 3-O-sulfate and 3-O-glucuronide of isoferulic acid, dihydro(iso)ferulic acid-3-O-glucuronide, and dihydrocaffeic acid-3-O-glucuronide. Overall, the 119.9 mumol excretion of the chlorogenic acid metabolites corresponded to 29.1% of intake, indicating that as well as being subject to extensive metabolism, chlorogenic acids in coffee are well absorbed. Pathways for the formation of the various metabolites within the body are proposed. Urinary dihydrocaffeic acid-3-O-sulfate and feruloylglycine are potentially very sensitive biomarkers for the consumption of relatively small amounts of coffee.
Chlorogenic acids (CGA) are cinnamic acid derivatives with biological effects mostly related to their antioxidant and antiinflammatory activities. Caffeoylquinic acids (CQA) and dicaffeoylquinic acids (diCQA) are the main CGA found in nature. Because green coffee is a major source of CGA, it has been used for production of nutraceuticals. However, data on the bioavailability of CGA from green coffee in humans are inexistent. The present study evaluated the pharmacokinetic profile and apparent bioavailability of CGA in plasma and urine of 10 healthy adults for 8 h after the consumption of a decaffeinated green coffee extract containing 170 mg of CGA. Three CQA, 3 diCQA, and caffeic, ferulic, isoferulic, and p-coumaric acids were identified in plasma by HPLC-Diode Array Detector-MS after treatment. Over 30% (33.1 +/- 23.1%) of the ingested cinnamic acid moieties were recovered in plasma, including metabolites, with peak levels from 0.5 to 8 h after treatment. CGA and metabolites identified in urine after treatment were 4-CQA, 5-CQA, and sinapic, p-hydroxybenzoic, gallic, vanillic, dihydrocaffeic, caffeic, ferulic, isoferulic, and p-coumaric acids, totaling 5.5 +/- 10.6% urinary recovery of the ingested cinnamic and quinic acid moiteties. This study shows that the major CGA compounds present in green coffee are highly absorbed and metabolized in humans.
The water extract of propolis (PWE) showed a strong hepatoprotective activity against CCl4-toxicity in rats and D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. The PWE also showed a significant hepatoprotective activity against CCl4-induced liver cell injury in cultured rat hepatocytes. The in vitro hepatoprotective activity guided fractionation and chemical analysis led to the isolation of four dicaffeoyl quinic acid derivatives from the PWE. The structure of these isolates was determined to be methyl 3,4-di-O-caffeoyl quinate (1), 3,4-di-O-caffeoyl quinic acid (2), methyl 4,5-di-O-caffeoyl quinate (3), and 3,5-di-O-caffeoyl quinic acid (4) by spectroscopic methods. These compounds were more potent hepatoprotective agents than glycyrrhizin at a concentration of 10 micrograms/ml and 1 was the most potent among the four compounds in the cultured hepatocytes. Quinic acid (5) alone did not show hepatoprotective effects in cultured rat hepatocytes against CCl4-toxicity. On the other hand, chlorogenic acid (6) or caffeic acid alone was found to be less potent than the dicaffeoyl quinic acid derivatives.
Chlorogenic acid, an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee; daily intake in coffee drinkers is 0.5-1 g. Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease. However, data on the absorption of chlorogenic acid and caffeic acid in humans are lacking. We determined the absorption of chlorogenic acid and caffeic acid in a cross-over study with 4 female and 3 male healthy ileostomy subjects. In such subjects, degradation by the colonic microflora is minimal and absorption can be calculated as the amount ingested minus the amount excreted in ileostomy effluent. The ileostomy subjects ingested 2.8 mmol chlorogenic acid and 2.8 mmol caffeic acid on separate days in random order and subsequently collected ileostomy fluid and urine for 24 h. Absorption of chlorogenic acid was 33 +/- 17% (mean +/- SD) and of caffeic acid 95 +/- 4%. Traces of the ingested chlorogenic acid and 11% of the ingested caffeic acid were excreted in urine. Thus, one third of chlorogenic acid and almost all of the caffeic acid were absorbed in the small intestine of humans. This implies that part of chlorogenic acid from foods will enter into the blood circulation, but most will reach the colon.
Polyphenols are abundant micronutrients in our diet, and evidence for their role in the prevention of degenerative diseases such as cancer and cardiovascular diseases is emerging. The health effects of polyphenols depend on the amount consumed and on their bioavailability. In this article, the nature and contents of the various polyphenols present in food sources and the influence of agricultural practices and industrial processes are reviewed. Estimates of dietary intakes are given for each class of polyphenols. The bioavailability of polyphenols is also reviewed, with particular focus on intestinal absorption and the influence of chemical structure (eg, glycosylation, esterification, and polymerization), food matrix, and excretion back into the intestinal lumen. Information on the role of microflora in the catabolism of polyphenols and the production of some active metabolites is presented. Mechanisms of intestinal and hepatic conjugation (methylation, glucuronidation, sulfation), plasma transport, and elimination in bile and urine are also described. Pharmacokinetic data for the various polyphenols are compared. Studies on the identification of circulating metabolites, cellular uptake, intracellular metabolism with possible deconjugation, biological properties of the conjugated metabolites, and specific accumulation in some target tissues are discussed. Finally, bioavailability appears to differ greatly between the various polyphenols, and the most abundant polyphenols in our diet are not necessarily those that have the best bioavailability profile. A thorough knowledge of the bioavailability of the hundreds of dietary polyphenols will help us to identify those that are most likely to exert protective health effects.
Chlorogenic acid, the ester of caffeic acid with quinic acid, is one of the most abundant polyphenols in the human diet. The antioxidant and anticarcinogenic properties of chlorogenic acid have been established in animal studies. However, little is known about the molecular mechanisms through which chlorogenic acid inhibits carcinogenesis. In this study, we found that chlorogenic acid inhibited the proliferation of A549 human cancer cells in vitro. The results of the soft agar assay indicated that chlorogenic acid suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation of JB6 P+ cells in a dose-dependent manner. Pretreatment of JB6 cells with chlorogenic acid blocked UVB- or TPA-induced transactivation of AP-1 and NF-kappaB over the same dose range. At low concentrations, chlorogenic acid decreased the phosphorylation of c-Jun NH2-terminal kinases, p38 kinase, and MAPK kinase 4 induced by UVB/12-O-tetradecanoylphorbol-13-acetate, yet higher doses were required to inhibit extracellular signal-regulated kinases. Chlorogenic acid also increased the enzymatic activities of glutathione S-transferases (GST) and NAD(P)H: quinone oxidoreductase. Further studies indicated that chlorogenic acid could stimulate the nuclear translocation of Nrf2 (NF-E2-related factor) as well as subsequent induction of GSTA1 antioxidant response element (ARE)-mediated GST activity. The phosphatidylinositol 3-kinase pathway might be involved in the activation of Nrf2 translocation. These results provide the first evidence that chlorogenic acid could protect against environmental carcinogen-induced carcinogenesis and suggest that the chemopreventive effects of chlorogenic acid may be through its up-regulation of cellular antioxidant enzymes and suppression of ROS-mediated NF-kappaB, AP-1, and MAPK activation.
Polyphenols are the most abundant antioxidants in the diet and are widespread constituents of fruits, vegetables, cereals, dry legumes, chocolate, and beverages, such as tea, coffee, or wine. Experimental studies on animals or cultured human cell lines support a role of polyphenols in the prevention of cardiovascular diseases, cancers, neurodegenerative diseases, diabetes, or osteoporosis. However, it is very difficult to predict from these results the effects of polyphenol intake on disease prevention in humans. One of the reasons is that these studies have often been conducted at doses or concentrations far beyond those documented in humans. The few clinical studies on biomarkers of oxidative stress, cardiovascular disease risk factors, and tumor or bone resorption biomarkers have often led to contradictory results. Epidemiological studies have repeatedly shown an inverse association between the risk of myocardial infarction and the consumption of tea and wine or the intake level of some particular flavonoids, but no clear associations have been found between cancer risk and polyphenol consumption. More human studies are needed to provide clear evidence of their health protective effects and to better evaluate the risks possibly resulting from too high a polyphenol consumption.
NF-kappaB family of transcription factors are involved in numerous cellular processes, including differentiation, proliferation, and inflammation. It was reported that hydroxycinnamic acid derivatives (HADs) are inhibitors of NF-kappaB activation. Rice bran oil contains a lot of phytosteryl ferulates, one of HADs. We have investigated effects of phytosteryl ferulates on NF-kappaB activation in macrophage. Cycloartenyl ferulate (CAF), one of phytosteryl ferulates, significantly reduced lipopolysaccharide (LPS)-induced NO production and mRNA expression of inducible NO synthase and cyclooxygenese-2 but upregulated SOD activity. Electrophoresis mobility shift assay revealed that CAF inhibited DNA-binding of NF-kappaB. CAF and phytosteryl ferulates probably have potentially anti-inflammatory properties.
Chlorogenic acids (CGA) are abundant phenolic compounds in coffee, with caffeoylquinic (CQA), feruloylquinic (FQA), and dicaffeoylquinic (diCQA) acids being the major subclasses. Despite the potential biopharmacological properties attributed to these compounds, little is known about their bioavailability in humans. In this study, we evaluated the distribution profile of the major CGA isomers and metabolites in plasma and urine of 6 healthy adults for 4 h after brewed coffee consumption. Three CQA isomers and 3 diCQA isomers were identified in the plasma of all subjects after coffee consumption, whereas 2 FQA were identified in only 1 subject. Two plasma concentration peaks were observed, the first at 0.5-1.0 h and the second at 1.5-4.0 h after coffee consumption. The molar ratio CQA:diCQA was 12.2 in the brewed coffee, whereas in plasma it ranged from 0.6-2.9. The molar ratios 5-CQA:3-CQA and 5-CQA:4-CQA were consistently higher in plasma than in the brew. The main CGA metabolites identified in urine after coffee consumption were: dihydrocaffeic, gallic, isoferulic, ferulic, vanillic, caffeic, 5-CQA, sinapic, rho-hydroxybenzoic, and rho-coumaric acids (gallic and dihydrocaffeic acids being the major ones). This study indicates that the major CGA compounds present in coffee are differentially absorbed and/or metabolized in humans, with a large inter-individual variation. Moreover, urine does not appear to be a major excretion pathway of intact CGA compounds in humans.
Cancer chemopreventive properties were evaluated in HPLC fractions of different polarity obtained from two cranberry juices and three extracts isolated from frozen cranberries and pomace containing anthocyanins, water-soluble and apolar phenolic compounds, respectively. Compounds with close polarities were collected in order to obtain between three and four fractions from each juice or extract. Cranberry fractions were screened for their ability to induce the phase II xenobiotic detoxification enzyme quinone reductase (QR). The results showed that there was no cytotoxicity against the cells used in the test. All samples stimulated the quinone reductase activity except the highest concentrations of the less polar fraction of anthocyanin-rich extract from pomace, which inhibited the QR activity. The QR induction for all samples varied with the concentration and there was an optimal concentration for which the QR induction was maximal. The technological process to manufacture cranberry juice had little influence on the overall QR inducer potencies of cranberry fractions, whereas the ability of phenols in fractions to stimulate the QR activity has been reduced significantly (P≤0.05) during the technological process. Among all samples, phenolic compounds of eight fractions presented a maximum QR induction greater than 100 II(QR)/mg phenol. The phenolic compounds of the most polar fraction (rich in phenolic acids) and those of the less polar fraction (rich in proanthocyanidins) showed stronger induction than those observed with phenols from intermediate fractions.
Mate is a tea-like beverage widely consumed in South America, prepared from the dried leaves of Ilex paraguariensis, St Hil. The total polyphenols (PP) and antioxidant activity of mate infusions and acid–methanol/acetone extracts were determined in three commercial brands, and compared to commonly consumed beverages like green and black teas, red, rosé and white wines, and orange juice. Mate had a PP content comparable to tea and orange juice, and, when normalized for the PP content of beverages, mate had an antioxidant activity slightly higher than wines, orange juice and black tea, but lower than green tea. LC/MS analysis of mate extracts showed that caffeoylquinic and dicaffeoylquinic acid isomers were the major components of the phenolic fraction of mate. Mixed mono-, di- and tri-esters of quinic acid and other hydroxycinnamates were also detected. Several quercetin and kaempferol glycosides were identified. Consumption of mate infusions would significantly contribute to the overall antioxidant intake, providing high amounts of caffeoylquinic acid derivatives, with biological effects potentially beneficial for human health.
Dietary polyphenols have been associated with reduced risk of chronic diseases, but the precise molecular mechanisms of protection remain unclear. This work was aimed at studying the effect of (-)-epicatechin (EC) and chlorogenic acid (CGA) on the regulation of apoptotic and survival/proliferation pathways in a human hepatoma cell line (HepG2). EC or CGA treatment for 18 h had a slight effect on cell viability and decreased reactive oxygen species formation, and EC alone promoted cell proliferation, whereas CGA increased glutathione levels. Phenols neither induced the caspase cascade for apoptosis nor affected expression levels of Bcl-xL or Bax. A sustained activation of the major survival signals AKT/PI-3-kinase and ERK was shown in EC-treated cells, rather than in CGA-exposed cells. These data suggest that EC and CGA have no effect on apoptosis and enhance the intrinsic cellular tolerance against oxidative insults either by activating survival/proliferation pathways or by increasing antioxidant potential in HepG2.
Yerba mate extract (Ilex paraguariensis) is a source of phenolic compounds that possesses in vitro antioxidant activities and may contribute to a reduction in the risk of cardiovascular disease. In this study we examined the acute effects of the consumption of mate infusion on ex vivo plasma and low-density lipoprotein (LDL) oxidation, plasma antioxidant capacity, and platelet aggregation. Twelve healthy fasted subjects ingested 500 mL of mate infusion and blood samples were collected before and 1 h after mate intake. Lipid peroxidation of plasma and LDL was monitored by the measurement of cholesteryl-ester hydroperoxides (CE-OOH) and cholesterol oxides. The plasma antioxidant capacity was measured as ferric-reducing antioxidant potential (FRAP). Platelet aggregation was evaluated in platelet-rich plasma stimulated with adenosine diphosphate and coagulation was tested in platelet-poor plasma. Ingestion of mate infusion diminished the ex vivo oxidizability of both plasma and LDL particles. After mate intake, the CE-OOH levels were around 50% lower in plasma oxidized with copper or 2,2′-azobis[2-amidine-propane-hydrochloride] (AAPH) and the lag time to plasma oxidation increased 2-fold (P < 0.05). Copper- and AAPH-induced LDL peroxidation were also inhibited by around 50% and 20%, respectively, after mate consumption (P < 0.05). The levels of various oxysterols were significantly reduced in oxidized-plasma and LDL (P < 0.05) and FRAP increased by 7.7% after mate intake (P < 0.01). However, mate consumption did not inhibit platelet aggregation or blood coagulation. In summary, intake of yerba mate infusion improved the antioxidant capacity and the resistance of plasma and LDL particles to ex vivo lipid peroxidation.
In this study, the effect of the 80% ethanolic extract of corn bran (EECB) on inhibition of nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells was investigated. The EECB inhibited LPS-induced NO production and iNOS expression in a dose-dependent manner. Four hydroxycinnamic acid derivatives (HADs), including two free cinnamic acids, p-coumaric acid (CA) and ferulic acid (FA), and their conjugate phenolic amides, p-dicoumaroyl-putrescine (DCP) and diferuloylputrescine (DFP), were found to be present in the EECB by LC-MS analysis, and DFP (378.66 μg/g) was the predominant phenolic compound, followed by DCP (7.83 μg/g)>CA (5.58 μg/g)>FA (1.84 μg/g). The four HADs significantly inhibited NO production and iNOS expression in a dose-dependent manner. Among the four HADs tested, DFP showed the most potent inhibition on NO production and iNOS mRNA and protein expression, followed by DCP>FA ≥ CA. DFP also exhibited the strongest inhibition on LPS-induced iNOS and NF-κB luciferase activity, which was followed by DCP ≥ FA (CA)>CA (FA). Thus, these results suggest that phenolic amides in the corn bran may be a potential source of natural anti-inflammatory agents.
Comparison of the effects of a high-fructose diet supplemented with rutin, a phenolic compound with well-recognized bioavailability and bioactivity, and a chicory (Cichorium intybus L.) seed extract rich in caffeoylquinic acids (CQA) on gut physiology and the development of disorders related to metabolic syndrome.
A 28-d experiment was conducted on 32 young male Wistar rats. In comparison with control rats fed a standard corn starch diet (group C), the experimental group (group E) was fed a diet with an increased content of cholesterol and fructose (to 1% and 66% of the diet, respectively), as well as with oxidized soybean oil. Rats from the other two experimental groups were administered the same diet as group E during the first 2 wk of feeding, whereas at the beginning of the last 2 wk, the diet was enriched with rutin (group ER) or the CQA-rich ethanol extract from chicory seeds (9.6% of CQA, group EC), so the amount of added phenolics was equal in both dietary groups (0.15%).
The diet administered in group E caused hyperglycemia and increased blood serum atherogenicity in rats, but did not induce other manifestations of the metabolic syndrome, i.e., dyslipidemia and oxidative stress. Additionally, it affected gut physiology through increasing mucosal sucrase activity and disturbing fermentative processes in the cecum, such as the production of short-chain fatty acids and the activity of microbial enzymes. Similarly to rutin, the dietary addition of the chicory seed extract improved glycemia, which was comparable to that determined in group C. In addition, the extract was found to decrease the atherogenic index to the level observed in group C and to increase blood antioxidant status. Both dietary supplements reduced the content of thiobarbituric acid-reactive substances in kidney and heart tissue when compared with group E.
The potential efficacy of the CQA-rich extract from chicory seeds in improving diet-induced metabolic disturbances proved to be better than that of rutin; thus, the extract might be considered as a dietary supplement for carrying out clinical trials.
Coffee contains a complex mixture of chlorogenic acids, which are mainly ferulic and caffeic acids ester-linked to quinic acid. Green tea contains flavanols, mainly (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC) and (-)-epicatechin (EC). For healthy humans, we identified seven studies on green tea in liquid form and five on coffee beverage reporting single-dose plasma pharmacokinetics. Weighted averages, based on the number of subjects, and elimination of outliers, allowed estimation of some pharmacokinetic parameters. After consumption of an "average" cup of green tea containing 112 mg of (-)-epigallocatechin gallate, 51 mg of EGC and 15 mg of EC in 200 mL, the predicted C(max) values (total free and sulfate/glucuronide conjugates) in plasma are 125, 181 and 76 nM, respectively, together with 94 nM methyl-EGC and 51 nM methyl-EC (standard deviation <20%). After consumption of an "average" cup of coffee (160 mg total chlorogenic acids (0.46 mmol)/200 mL), predicted C(max) values of caffeic, ferulic, isoferulic, dihydrocaffeic and dihydroferulic acids are 114, 96, 50, 384 and 594 nM, respectively (too few studies to calculate standard deviation). Most studies report a very low amount of intact chlorogenic acids in plasma, with one exception. More studies on absorption of chlorogenic acids from coffee are required, including dose-response studies.
Epidemiological and animal studies have shown that dietary fiber is protective against the development of colon cancer. Dietary fiber is a rich source of the hydroxycinnamic acids ferulic acid (FA) and p-coumaric acid (p-CA), which both may contribute to the protective effect. We have investigated the effects of FA and p-CA treatment on global gene expression in Caco-2 colon cancer cells. The Caco-2 cells were treated with 150 μM FA or p-CA for 24 h, and gene expression was analyzed with cDNA microarray technique. A total of 517 genes were significantly affected by FA and 901 by p-CA. As we previously have found that FA or p-CA treatment delayed cell cycle progression, we focused on genes involved in proliferation and cell cycle regulation. The expressions of a number of genes involved in centrosome assembly, such as RABGAP1 and CEP2, were upregulated by FA treatment as well as the gene for the S phase checkpoint protein SMC1L1. p-CA treatment upregulated CDKN1A expression and downregulated CCNA2, CCNB1, MYC, and ODC1. Some proteins corresponding to the affected genes were also studied. Taken together, the changes found can partly explain the effects of FA or p-CA treatment on cell cycle progression, specifically in the S phase by FA and G(2)/M phase by p-CA treatment.
Hydroxytyrosol (HTy) is a natural polyphenol abundant in olive oil, which possesses multiple biological actions. Particularly, HTy has cytoprotective activity against oxidative-stress-induced cell damage, but the underlying mechanisms of action remain unclear. Here, we have investigated the molecular mechanism involved in the protection exerted by HTy on tert-butyl hydroperoxide-induced damage in human HepG2 liver cells. Treatment of HepG2 cells with HTy increased the expression and the activity of glutathione-related enzymes such as glutathione peroxidase, glutathione reductase and glutathione S-transferase. HTy also induced the nuclear transcription factor erythroid 2p45-related factor (Nrf2), a transcription factor implicated in the expression of several antioxidant/detoxificant enzymes. Moreover, two important signalling proteins involved in Nrf2 translocation, the protein kinase B and the extracellular regulated kinases, were also activated by HTy. Further studies with specific inhibitors confirmed that both molecular pathways are critical for the nuclear translocation of Nrf2, the increased enzyme expression and activity and the beneficial effect against oxidative stress induced by HTy. In conclusion, together with the inherent radical scavenging activity of HTy, our results provide an additional mechanism of action to prevent oxidative stress damage through the modulation of signalling pathways involved in antioxidant/detoxifying enzymes regulation.
Oxidative stress is widely recognized as an important mediator of apoptosis in liver cells and plays a pivotal role in the pathogenesis of several diseases. Cocoa flavonoids have shown a powerful antioxidant activity providing protection against oxidation and helping prevent oxidative stress-related diseases. However, the molecular mechanisms responsible for this protection are not fully understood. Thus, in this study we investigated the protective effect of a cocoa polyphenolic extract (CPE) against tert-butyl hydroperoxide (t-BOOH)-induced apoptosis and the molecular mechanisms involved in this process. Incubation of HepG2 cells with t-BOOH induced apoptosis as evidenced by caspase-3 activation. This effect was accompanied by increased reactive oxygen species formation and by transient activation of the extracellular regulated kinases (ERKs) as well as sustained activation of the c-Jun N-terminal kinases (JNKs). On the contrary, pretreatment of HepG2 cells with CPE prevented apoptosis through the reduction of reactive oxygen species generation and the modulation of the apoptotic pathways activated by t-BOOH. CPE treatment also activated survival signaling proteins, such as protein kinase B (AKT) and ERKs, and increased the activities of two antioxidant enzymes, glutathione peroxidase (GPx) and glutathione reductase (GR). ERK's implication on GPx and GR induction and the protective effect of CPE against t-BOOH-induced oxidative stress and apoptosis were confirmed through experiments with selective inhibitors. These findings suggest that CPE is an effective inductor of GPx and GR activities via ERK activation and that this up-regulation seems to be required to attenuate t-BOOH-induced injury.
Cocoa is a rich source of flavanols and procyanidin oligomers with antioxidative properties, providing protection against oxidation and nitration. The present study investigated the potential protective effect of a polyphenolic extract from cocoa on cell viability and antioxidant defenses of cultured human HepG2 cells submitted to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Pretreatment of cells with 0.05-50 microg/mL of cocoa polyphenolic extract (CPE) for 2 or 20 h completely prevented cell damage and enhanced activity of antioxidant enzymes induced by a treatment with t-BOOH. Moreover, lower levels of GSH caused by t-BOOH in HepG2 cells were partly recovered by a pretreatment with CPE. Increased reactive oxygen species (ROS) induced by t-BOOH was dose-dependently prevented when cells were pretreated for 2 or 20 h with CPE. These results show that treatment of HepG2 in culture with CPE (within the physiological range of concentrations) confers a significant protection against oxidation to the cells.
Absorption of orally administered chlorogenic acid (5-caffeoylquinic acid) and caffeic acid in rats was studied to obtain plasma pharmacokinetic profiles of their metabolites. Rats were administered 700 micromol/kg body weight of chlorogenic or caffeic acid, and blood was collected from the tail for 6 h after administration. Ingested caffeic acid was absorbed from the alimentary tract and was present in the rat blood circulation in the form of various metabolites. On the other hand, only traces of metabolites, supposedly caffeic and ferulic acids conjugates, were detected in rat plasma for 6 h after chlorogenic acid administration. Chlorogenic acid and small amounts of caffeic acid were found in the small intestine for 6 h after chlorogenic acid administration. These results suggest that chlorogenic acid is not well absorbed from the digestive tract, unlike caffeic acid, and subject to almost no structural changes to the easily absorbed forms.
The oxidative modification of proteins by reactive species, especially reactive oxygen species, is implicated in the etiology or progression of a panoply of disorders and diseases. For the most part, oxidatively modified proteins are not repaired and must be removed by proteolytic degradation. The level of these modified molecules can be quantitated by measurement of the protein carbonyl content, which has been shown to increase in a variety of diseases and processes, most notably during aging. However, these studies have required invasive techniques to obtain cells for analysis. We examined the possibility that desquamating skin cells (corneocytes) would also show an age-related increase in protein carbonyl content, thus providing a noninvasive method for assessing biological age. This was not the case, as we found no age-dependent relationship in the protein carbonyl content of skin cells from volunteers aged 20 to 79 years.
Dried plums are known as a healthy food in the West and used as medicine in India. They have been characterized by high concentrations of phenolic compounds, which are believed to play a crucial role in protection against various age-related diseases. Liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) with four different conditions was used to analyze the phytochemicals in commercial dried plums. The major components were neochlorogenic acid and cryptochlorogenic acid. Forty minor components were characterized by their MS/MS spectra and LC retention time. Six of them are novel ester isomers formed by two caffeic acids and one quinic acid. The diagnostic fragmentation patterns of different phenolics are presented on the basis of electrospray ionization (ESI) MS/MS data of components in dried plums and fourteen authentic standards.
Despite extensive literature describing the biological effects of polyphenols, little is known about their absorption from diet, one major unresolved point consisting of the absorption of the bound forms of polyphenols. In this view, in the present work we studied the absorption in humans of phenolic acids from coffee, a common beverage particularly rich in bound phenolic acids, such as caffeic acid, ferulic acid, and p-coumaric acid. Coffee brew was analyzed for free and total (free + bound) phenolic acids. Chlorogenic acid (5'-caffeoylquinic acid), a bound form of caffeic acid, was present in coffee at high levels, while free phenolic acids were undetectable. After alkaline hydrolysis, which released bound phenolic acids, ferulic acid, p-coumaric acid, and high levels of caffeic acid were detected. Plasma samples were collected before and 1 and 2 h after coffee administration and analyzed for free and total phenolic acid content. Two different procedures were applied to release bound phenolic acids in plasma: beta-glucuronidase treatment and alkaline hydrolysis. Coffee administration resulted in increased total plasma caffeic acid concentration, with an absorption peak at 1 h. Caffeic acid was the only phenolic acid found in plasma samples after coffee administration, while chlorogenic acid was undetectable. Most of caffeic acid was present in plasma in bound form, mainly in the glucuronate/sulfate forms. Due to the absence of free caffeic acid in coffee, plasma caffeic acid is likely to be derived from hydrolysis of chlorogenic acid in the gastrointestinal tract.
Malondialdehyde (MDA) is considered a presumptive biomarker for lipid peroxidation in live organisms and cultured cells. The present study adapts an accurate and reproducible method to measure MDA by high-performance liquid chromatography (HPLC) as its 2,4-dinitrophenylhydrazone derivative in human hepatoma HepG2 cells in culture. Since MDA is assumed to increase in conditions of cellular oxidative stress, two compounds that induce pharmacological oxidative stress in cell cultures, hydrogen peroxide (H(2)O(2)) and tert-butyl hydroperoxide (t-BOOH), have been used in HepG2 cells. The results report a significant increase in the content of MDA derivative after treatment with 200 and 500microM t-BOOH for 3h, while H(2)O(2) in doses up to 500microM failed to evoke a similar response, indicating a stronger lipid peroxidation of t-BOOH to HepG2 cells than H(2)O(2). Thus, MDA can be used as a reliable biomarker for cellular oxidative stress in human hepatoma HepG2.
It is believed that anticancer and apoptosis inducing properties of green tea are mediated by it's polyphenolic constituents particularly catechins. A number of reports have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) is among the most effective chemopreventive and apoptosis-inducing agents present in the beverage. Plant polyphenols are naturally occurring antioxidants but they also exhibit prooxidant properties. Over the last several years we have shown that various classes of plant polyphenols including flavonoids, curcuminoids and tannins are capable of catalyzing oxidative DNA cleavage particularly in the presence of transition metal ions such as copper and iron. With a view to understand the chemical basis of various pharmacological properties of green tea, in this paper we have compared the prooxidant properties of green tea polyphenols--EGCG and EC ((-)-epicatechin). The rate of oxidative DNA degradation as well as hydroxyl radical and superoxide anion formation was found to be greater in the case of EGCG as compared with EC. It was also shown that copper mediated oxidation of EC and EGCG possibly leads to the formation of polymerized polyphenols. Further, it was indicated that copper oxidized catechins were more efficient prooxidants as compared with their unoxidized forms. These results correlate with the observation by others that EGCG is the most effective apoptosis inducing polyphenol present in green tea. They are also in support of our hypothesis that prooxidant action of plant polyphenols may be an important mechanism of their anticancer properties. A model for binding of Cu(II) to EC has been presented where the formation of quinone and a quinone methide has been proposed.
Flavonols such as quercetin, have been reported to exhibit a wide range of biological activities related to their antioxidant capacity. The objective of the present study was to investigate the protective effect of quercetin on cell viability and redox status of cultured HepG2 cells submitted to oxidative stress induced by tert-butyl hydroperoxide. Concentrations of reduced glutathione and malondialdehyde, generation of reactive oxygen species and activity and gene expression of antioxidant enzymes were used as markers of cellular oxidative status. Pretreatment of HepG2 with 10 microM quercetin completely prevented lactate dehydrogenase leakage from the cells. Pretreatment for 2 or 20 h with all doses of quercetin (0.1-10 microM) prevented the decrease of reduced glutathione and the increase of malondialdehyde evoked by tert-butyl hydroperoxide in HepG2 cells. Reactive oxygen species generation induced by tert-butyl hydroperoxide was significantly reduced when cells were pretreated for 2 or 20 h with 10 microM and for 20 h with 5 microM quercetin. Finally, some of the quercetin treatments prevented the significant increase of glutathione peroxidase, superoxide dismutase, glutathione reductase and catalase activities induced by tert-butyl hydroperoxide. Gene expression of antioxidant enzymes was also affected by the treatment with the polyphenol. The results of the biomarkers analyzed clearly show that treatment of HepG2 cells in culture with the natural dietary antioxidant quercetin strongly protects the cells against an oxidative insult.
Following exposure of differentiated neuronal PC12 cells to either t-BHP, hydrogen peroxide (H2O2) or FeSO4 various kinds of reactive oxygen species (ROS) are generated leading to oxidative injury. The protective effects of two plant polyphenols, ellagic (EC) and chlorogenic acid (CGA), as well as of two metabolites, caffeic acid (CA) and ferulic acid (FA), were investigated in preincubation and coincubation experiments with respect to the following parameters: prevention of cell death, GSH depletion, lipid peroxidation and ROS formation. The polyphenols more efficiently suppressed cytotoxicity and loss of GSH caused by peroxides than by iron, particularly in preincubation. Lipid peroxidation which increased much stronger in response to FeSO4 was counteracted completely by the polyphenols. In case of iron, however, only coincubation was effective. EA and CGA and the metabolites CA and FA showed excellent elimination of ROS induced by all stressors. These findings suggest that two dietary antioxidants, EA and CGA, may have protective properties against oxidative stress induced in CNS.
To study the potential hepatic metabolism of olive oil phenols, human hepatoma HepG2 cells were incubated for 2 and 18 h with hydroxytyrosol, tyrosol, and hydroxytyrosyl acetate, three phenolic constituents of olive oil. After incubation, culture media and cell lysates were hydrolyzed with beta-glucuronidase and sulfatase and analyzed by LC-MS. In vitro methylation, glucuronidation, and sulfation of pure phenols were also performed. Methylated and glucuronidated forms of hydroxytyrosol were detected at 18 h of incubation, together with methylglucuronidated metabolites. Hydroxytyrosyl acetate was largely converted into free hydroxytyrosol and subsequently metabolized, yet small amounts of glucuronidated hydroxytyrosyl acetate were detected. Tyrosol was poorly metabolized, with <10% of the phenol glucuronidated after 18 h. Minor amounts of free or conjugated phenols were detected in cell lysates. No sulfated metabolites were found. In conclusion, olive oil phenols can be metabolized by the liver as suggested by the results obtained using HepG2 cells as a hepatic model system.
The bioavailability of chlorogenic acid, a major polyphenol of the human diet that is particularly abundant in coffee and various fruits, was explored in rats. To identify the form under which it is absorbed through the gut mucosa and the site of absorption along the gastrointestinal tract, rats were fed a diet supplemented with chlorogenic acid (0.25%, wt:wt). Chlorogenic acid and its metabolites were estimated in the stomach, small intestine and cecal contents as well as in bladder urine and plasma by HPLC with coulometric detection at several time points (1.5, 3, 4.5, and 7 h) after the beginning of the meal. Minor hydrolysis of chlorogenic acid (<1%) occurred in the stomach and small intestine contents, whereas 15-32% of ingested chlorogenic acid was hydrolyzed into caffeic acid in the cecum. Chlorogenic acid and caffeic acid appeared early (at 1.5 h) in plasma and urine, suggesting an absorption of chlorogenic acid into the upper part of the gastrointestinal tract. Gastric absorption of chlorogenic acid was further examined by infusing chlorogenic acid in the ligated stomach of food-deprived rats. After 30 min of infusion, intact chlorogenic acid was found in the gastric vein and aorta. No other metabolites could be detected by HPLC-electrospray ionization-MS-MS. These results show for the first time that chlorogenic acid is quickly absorbed in the rat stomach in its intact form.
In the present work, the potential hepatoprotective effects of five phenolic compounds against oxidative damages induced by tert-butyl hydroperoxide (t-BHP) were evaluated in HepG2 cells in order to relate in vitro antioxidant activity with cytoprotective effects. t-BHP induced considerable cell damage in HepG2 cells as shown by significant LDH leakage, increased lipid peroxidation, DNA damage as well as decreased levels of reduced glutathione (GSH). All tested phenolic compounds significantly decreased cell death induced by t-BHP (when in co-incubation). If the effects of quercetin are given the reference value 1, the compounds rank in the following order according to inhibition of cell death: luteolin (4.0) > quercetin (1.0) > rosmarinic acid (0.34) > luteolin-7-glucoside (0.30) > caffeic acid (0.21). The results underscore the importance of the compound's lipophilicity in addition to its antioxidant potential for its biological activity. All tested phenolic compounds were found to significantly decrease lipid peroxidation and prevent GSH depletion induced by t-BHP, but only luteolin and quercetin significantly decreased DNA damage. Therefore, the lipophilicity of the natural antioxidants tested appeared to be of even greater importance for DNA protection than for cell survival. The protective potential against cell death was probably achieved mainly by preventing intracellular GSH depletion. The phenolic compounds studied here showed protective potential against oxidative damage induced in HepG2 cells. This could be beneficial against liver diseases where it is known that oxidative stress plays a crucial role.
Antioxidative flavonoids, ubiquitously included in vegetables, fruits and teas, are expected to prevent degenerative diseases. It is unclear, however, whether flavonoids can enter the cellular nuclei and suppress the oxidative damage of DNA. Here, several flavonoids at the physiological concentration of 10 microM were dosed to 2.5x10(7) HepG2 cells. The nuclei were isolated and determined in the incorporated flavonoid levels, and simultaneously exposed to reactive oxygen generated from 25 mM of 2,2'-azobis(2-amidinopropane) dihydrochloride. Most of the tested flavonoids were incorporated into the cells in the range between 1000 and 1600 pmol/10(7) cells, and were in the nuclei at 250-450 pmol/10(7) cells at the maximum incorporation after 30min of cell incubation. In the cells, 23% of quercetin (3,5,7,3',4'-OH) and 8% of luteolin (5,7,3',4'-OH) were the original aglycone forms and the others were the methylated and gulucuronide/sulfate conjugates, while 72% of kaempferol (3,5,7,4'-OH) and 85% of apigenin (5,7,4'-OH) were aglycones and located in the nuclei at the similar ratio of metabolites. Quercetin and luteolin significantly suppressed the formation of 8-oxo-7,8-dihydrodeoxyguanosine by 25% and 15%, respectively, compared to those in 0-time incubated cells with the flavonoids. Under such conditions of low level and hydroxyl-masked in the nuclei, the limited flavonoids were bioavailable antioxidants to prevent genetic damage and they were B-ring catechols such as quercetin and luteolin.
Hydroxycinnamic acids are antioxidant polyphenols common in the human diet, although their potential health benefits depend on their bioavailability. To study the hepatic uptake and metabolism, human hepatoma HepG2 cells were incubated for 2 and 18 h with caffeic, ferulic, and chlorogenic acids. Moderate uptake of caffeic and ferulic acids was observed versus a low absorption of chlorogenic acid, where esterification of the caffeic acid moiety markedly reduced its absorption. Methylation was the preferential pathway for caffeic acid metabolism, along with glucuronidation and sulfation, while ferulic acid generated glucuronides as the only metabolites. Ferulic acid appeared to be more slowly taken up and metabolized by HepG2 cells than caffeic acid, with 73% and 64% of the free, nonmetabolized molecules detected in the culture medium after 18 h, respectively. In conclusion, hydroxycinnamic acids can be metabolized by the liver as suggested by the results obtained using HepG2 cells as a hepatic model system.
- A J León-González
A.J. León-González et al. / Food Research International 49 (2012) 728–738