Grape Seed Components as Protectors of Inflammation, DNA Damage, and Cancer.

PURPOSE OF REVIEW: Oxidative stress is related to the pathogenesis of several chronic diseases, including inflammatory processes. Free radicals excess increase not only oxidative stress but also genomic instability. Polyphenols are non-enzymatic antioxidants that act as a defense barrier against free radicals and non-radical oxidants. The purpose of this article was to review published articles relating dietary polyphenols contained in grape seed proanthocyanidin extracts with its potential for reversing DNA damage. RECENT FINDINGS: Proanthocyanidin components exert pleiotropic actions having several biological, biochemical, and significant pharmacological effects and showed the ability to reduce cytotoxicity and genotoxicity. Grape seed proanthocyanidin extracts showed the ability to reduce cytotoxicity and genotoxicity through the comet assay and the micronucleus technique.

Proanthocyanidins in grape seeds and their role in gut microbiota-white adipose tissue axis.

Several factors can impact the gut microbiota, affecting host metabolism and immunity. It implies intestinal barrier disruption and translocation of gut microbiota metabolites to the bloodstream, such as lipopolysaccharides (LPS). LPS is an endotoxin from gram-negative gut bacteria that trigger the activation of the Toll-like receptor-4 (TLR-4) inflammatory pathway and can modulate white adipose tissue (WAT) metabolism. Dietary components, including diets rich in fiber and polyphenols, contribute to intestinal environment homeostasis. Grape seed proanthocyanidins extract (GSPE) may improve intestinal permeability and microbial diversity and increase short-chain fatty acids production. Furthermore, GSPE has been involved in LPS reduction, down-regulating the TLR-4 pathway, decreasing the WAT metainflammatory profile, and preventing adipocyte hypertrophy. Studies have pointed out strategies to promote health and control obesity by modulating the gut microbiota environment. Therefore, this review aims to summarize the potential effects of GSPE on the gut microbiota-white adipose tissue axis against obesity.

Effects of passion fruit (Passiflora tenuifila Killip) intake on eutrophic and obese subjects: Lipidomic approach

Obesity and overweight result in metabolic changes that build up as risk factors for the development of the main non-communicable diseases. Among these alterations, dyslipidemia is an important risk factor for cardiovascular diseases (CDV) and is expressed in elevated plasma levels of triacylglycerols, cholesterol, and low-density-lipoprotein (LDL, VLDL) and decreased plasma levels of high-density lipoprotein (HDL). Passiflora tenuifila Killip is a native passion fruit species of the Brazilian Midwest region and is a good source of proanthocyanidins and dietary fibers. Proanthocyanidins are a class of phenolic compounds that are attributed with improving lipoprotein profile properties, translated as improved LDL/HDL ratio. Fibers are fermented by the gut microbiota and produce short-chain fatty acids (SCFA), also involved in the regulation of energetic metabolism.. A 30-consecutive-day-long intervention with lyophilized P. tenuifila flour was performed in eutrophic and obese subjects. Passion fruit ingestion increased fecal production of acetate, key SCFA in the modulation of lipid metabolism; reduced body fat percentage in all subjects; and reduced total cholesterol (TC) of subjects who presented basal CT > 130 mg/dL. After the intervention, plasma lipidomic analysis detected 44 statistically significant lipids, regardless of BMI. Considering the study population with altered TC, reduced levels of glycerophospholipids were observed, a lipid class studied for their involvement in CVD. The intake of P. tenuifila contributed to the improvement in cardiovascular risk markers and acts on lipid metabolism. These effects may be due to synergic action between the bioactive compounds in the fruit. Still, other studies are necessary to identify mechanisms related to the action of bioactives of P. tenuifila, which can be better directed by this lipidomic approach

A obesidade e o sobrepeso são preocupações resultam em alterações metabólicas que se acumulam como fatores de risco para o desenvolvimento a longo prazo das principais doenças crônicas não transmissíveis. Dentre essas alterações, a dislipidemia um importante fator de risco para doenças cardiovasculares (DCV), expressa em níveis plasmáticos elevados de triacilgliceróis, colesterol e das lipoproteínas de baixa densidade (VLDL, LDL), e níveis diminuídos da lipoproteína de alta densidade (HDL). Passiflora tenuifila Killip é uma espécie de maracujá nativa da região Centro-Oeste brasileira, e é uma boa fonte de proantocianidinas e fibras alimentares. As proantocianidinas são compostos fenólicos com reportados efeitos na melhora do perfil de lipoproteínas, traduzida como a relação LDL/HDL. As fibras são fermentadas pela microbiota intestinal e produzem ácidos graxos de cadeia curta (AGCC), metabólitos também envolvidos na regulação do metabolismo energético.. Assim, a lipidômica não-target é aplicada como ferramenta exploratória neste estudo: uma intervenção de 30 dias consecutivos de ingestão de P. tenuifila na forma de farinha liofilizada em indivíduos eutróficos e obesos. O consumo do maracujá promoveu aumento da produção fecal de acetato, AGCC importante na modulação do metabolismo lipídico; a redução do percentual de gordura corporal em todos os indivíduos; e redução do colesterol total (CT) para os indivíduos com CT > 130 mg/dL. A análise lipidômica do plasma detectou 44 lipídios estatisticamente relevantes, independentemente do IMC, após a intervenção. Considerando a população do estudo com CT alterado, foi observada uma redução de glicerofosfolipídios, classe de lipídios estudada pelo seu envolvimento em DCV. Assim, a ingestão de P. tenuifila contribui para a melhora nos marcadores de risco cardiovascular e atua no metabolismo lipídico. Estes efeitos podem ser decorrentes de sinergia entre os diversos compostos bioativos do fruto. Ainda, outros estudos são necessários para identificar mecanismos relacionados a ação dos bioativos da P. tenuifila e estes podem ser mais bem direcionados pela lipidômica

Effect of 10% Proanthocyanidin gel on demineralized organic matrix degradation: ELISA method / Efeito do gel de Proantocianidina a 10% na degradação da matriz orgânica desmineralizada: método ELISA

Objective: This study evaluated Proanthocyanidin protective effect on dentin subjected to erosion and its inhibition on degradation of the demineralized organic matrix (DOM). Material and Methods: The tested groups were: G1 - 10% Proanthocyanidin gel (test group), G2 - 1.23% NaF (positive control 1), G3 - 0.012% Chlorhexidine (positive control 2) and G4 ­ Placebo (negative control with no active compound) and two methodologies were performed: contact profilometry and ICTP ELISA method. To quantify dentin wear, profilometry was performed. Data were submitted to Analysis of Variance followed by Fisher's LSD Test. To assess the collagen degradation, ICTP ELISA method was performed. Data were submitted to the Kruskal-Wallis followed by the Dunn ́s test. Simple linear regression and Pearson Correlation test were also performed (p<0.05). Results: The profilometry showed significantly lower wear of G1 when compared to other groups and G2, G3 and G4, which did not present significant difference among them. In the ICTP ELISA analysis, G1 and G4 did not show significant differences and the same happened between G2 and G3. However, G1 and G4 had lower values of collagen degradation compared to groups G2 and G3. Data showed that degraded DOM is a significant predictor to explain the values obtained through the ICTP ELISA. Conclusions: The results allow to verify that 10% proanthocyanidin provided less tooth wear and decreased degradation of the DOM, suggesting a good ability to prevent dentin erosion. The regression analysis also suggests that contact profilometry is a good strategy to quantify dentin wear (AU)

Objetivo: Este estudo avaliou o efeito protetor da proantocianidina na dentina submetida à erosão e sua inibição na degradação da matriz orgânica desmineralizada (MOD). Material e Métodos: Os grupos testados foram: G1 - gel de Proantocianidina 10% (grupo teste), G2 - NaF 1,23% (controle positivo 1), G3 - Clorexidina 0,012% (controle positivo 2) e G4 - Placebo (controle negativo sem princípio ativo) e duas metodologias foram realizadas: perfilometria de contato e método ICTP ELISA. Para quantificar o desgaste da dentina, a perfilometria foi realizada. Os dados foram submetidos à Análise de Variância seguida do Teste LSD de Fisher. Para avaliar a degradação do colágeno, foi realizado o método ICTP ELISA. Resultados: Os dados foram submetidos ao teste de Kruskal-Wallis seguido do teste de Dunn. Regressão linear simples e teste de correlação de Pearson também foram realizados (p<0,05). A perfilometria mostrou desgaste significativamente menor do G1 quando comparado aos outros grupos e G2, G3 e G4, que não apresentaram diferença significativa entre si. Na análise ICTP ELISA, G1 e G4 não apresentaram diferenças significativas e o mesmo ocorreu entre G2 e G3. No entanto, G1 e G4 apresentaram valores menores de degradação do colágeno em relação aos grupos G2 e G3. Os dados mostraram que a MOD degradada é um preditor significativo para explicar os valores obtidos pelo ICTP ELISA. Conclusão: Os resultados permitem verificar que a proantocianidina a 10% proporcionou menor desgaste dentário e diminuição da degradação da MOD, sugerindo uma boa capacidade de prevenir a erosão dentinária. Também sugere que a perfilometria de contato é uma boa estratégia para quantificar o desgaste da dentina (AU)

The Effect on Hemostasis of Gelatin-Graphene Oxide Aerogels Loaded with Grape Skin Proanthocyanidins: In Vitro and In Vivo Evaluation.

Using in vitro and in vivo models, this study investigated the hemostatic potential to control bleeding of both unloaded gelatin-graphene oxide aerogels and the same loaded with proanthocyanidins (PAs) from Vitis vinifera grape skin extract. Our results showed that the physicochemical and mechanical properties of the aerogels were not affected by PA inclusion. In vitro studies showed that PA-loaded aerogels increased the surface charge, blood absorption capacity and cell viability compared to unloaded ones. These results are relevant for hemostasis, since a greater accumulation of blood cells on the aerogel surface favors aerogel-blood cell interactions. Although PAs alone were not able to promote hemostasis through extrinsic and intrinsic pathways, their incorporation into aerogels did not affect the in vitro hemostatic activity of these composites. In vivo studies demonstrated that both aerogels had significantly increased hemostatic performance compared to SpongostanTM and gauze sponge, and no noticeable effects of PA alone on the in vivo hemostatic performance of aerogels were observed; this may have been related to its poor diffusion from the aerogel matrix. Thus, PAs have a positive effect on hemostasis when incorporated into aerogels, although further studies should be conducted to elucidate the role of this extract in the different stages of hemostasis.

Metabolomic profiling and correlations of supercritical extracts of guarana.

A previous optimization of supercritical extraction from guarana seeds was performed applying orthogonal array design (OA9(34)). The antioxidant and antimicrobial activities of these extracts, as well as metabolomic profiling and correlations from the compounds by statistical analysis were determined. Extracts 1 (40% ethanol; 20 min; 40 °C and 100 bar), 2 (40% methanol; 60 min; 40 °C and 200 bar), and 8 (40% methanol; 40 min; 60 °C and 100 bar) had the highest combined values of antioxidant capacity for the DPPH, FRAP, ABTS and xanthine oxidase system methods, and were identified by chemometric analysis. Similar chemical profiles of the extracts were obtained by LC-DAD-MS, and were identified: methyl-xanthine, (epi)catechin and dimers and trimers of type A and B proanthocyanidins. The heat map analysis showed positive correlation between antioxidant methods DPPH, FRAP and ABTS and with flavan-3-ols and proanthocyanidins. Extract 3 was active against Gram-negative and -positive bacteria and Candida tropicalis.

Hybrid Nanoparticles of Proanthocyanidins from Uncaria tomentosa Leaves: QTOF-ESI MS Characterization, Antioxidant Activity and Immune Cellular Response.

Previous studies in Uncaria tomentosa have shown promising results concerning the characterization of polyphenols with leaves yielding more diverse proanthocyanidins and higher bioactivities values. However, the polyphenols-microbiota interaction at the colonic level and their catabolites avoid the beneficial effects that can be exerted by this medicinal plant when consumed. In this regard, a new generation of hybrid nanoparticles has demonstrated improvements in natural compounds' activity by increasing their bioavailability. In this line, we report a detailed study of the characterization of a proanthocyanidin-enriched extract (PA-E) from U. tomentosa leaves from Costa Rica using UPLC-QTOF-ESI MS. Moreover, two types of hybrid nanoparticles, a polymeric-lipid (F-1) and a protein-lipid (F-2) loaded with PA-E were synthesized and their characterization was conducted by dynamic light scattering (DLS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR), high-resolution transmission electron microscopy (HR-TEM), and encapsulation efficiency (%EE). In addition, in vitro release, antioxidant activity through 2,2-diphenyl-1-picrylhidrazyl (DPPH) as well as in vivo delayed-type hypersensitivity (DTH) reaction was evaluated. Results allowed the identification of 50 different compounds. The PA-E loaded nanoparticles F-1 and F-2 achieved encapsulation efficiency of ≥92%. The formulations exhibited porosity and spherical shapes with a size average of 26.1 ± 0.8 and 11.8 ± 3.3 nm for F-1 and F-2, respectively. PA-E increased its release rate from the nanoparticles compared to the free extract in water and antioxidant activity in an aqueous solution. In vivo, the delayed-type hypersensitive test shows the higher immune stimulation of the flavan-3-ols with higher molecular weight from U. tomentosa when administered as a nanoformulation, resulting in augmented antigen-specific responses. The present work constitutes to our knowledge, the first report on these bioactivities for proanthocyanidins from Uncaria tomentosa leaves when administrated by nanosystems, hence, enhancing the cellular response in mice, confirming their role in immune modulation.

Regulation of interleukin-6 and matrix metalloproteinases syntheses by bioflavonoids and photobiomodulation in human gingival fibroblasts.

This study aimed to evaluate the separately effects of bioflavonoids proanthocyanidins, from grape seed extract (GSE) and synthetic naringenin (NA), as well as photobiomodulation (PBM) by low-level laser therapy on interleukin (IL)-6 and matrix metalloproteinases (MMPs) syntheses by human gingival fibroblasts (HGF). For this purpose, a connective tissue exposure (ulceration) model of HGF, stimulated with tumor necrosis factor-alpha (TNF-α), was used. Initially, the highest non-cytotoxic and non-genotoxic concentrations of bioflavonoids were determined by cell viability and micronuclei formation assays. Then, HGF were exposed to different stimuli: culture medium (negative control), dimethyl sulfoxide (DMSO), TNF-α, NA, GSE, TNF-α + NA, TNF-α + GSE, PBM (3 J/cm2, 0.025 W, 780 nm), and TNF-α + PBM. Next, IL-6, MMP-2, and MMP-9 syntheses were assessed. The concentration of 10 µg/mL of bioflavonoids increased cell viability at 24 and 48 h and did not present cytotoxic or genotoxic effects on HGF after 24, 48, and 72 h of contact. This concentration was selected for the assessment of bioflavonoids potential in modulating inflammatory mediators. TNF-α exposure enhanced IL-6 (170%), MMP-2 (10%), and MMP-9 (20%) syntheses, while a decrease of MMP-2 by 55% after exposure to TNF-α + GSE and 20% after TNF-α + NA and TNF-α + PBM was observed. MMP-9 synthesis was decreased by 35% after TNF-α + NA, 20% after TNF-α + GSE, and 30% after PBM. IL-6 was down-regulated by GSE in the presence of TNF-α (80%). In conclusion, TNF-α up-regulated IL-6 and MMPs, while bioflavonoids and PBM down-regulated MMP-2 and MMP-9 syntheses; GSE also decreased IL-6 synthesis, demonstrating the individual promising potential of these therapies for ulceration management.

Effect of cranberry supplementation on toxins produced by the gut microbiota in chronic kidney disease patients: A pilot randomized placebo-controlled trial.

BACKGROUND & AIMS: Patients with Chronic Kidney Disease (CKD) have an imbalance in the gut microbiota that can lead to increase levels of lipopolysaccharides (LPS) and uremic toxins such as indoxyl sulfate (IS), p-cresyl sulfate (p-CS), and indole-3 acetic acid (IAA). Among the therapeutic options for modulating gut microbiota are the bioactive compounds such as polyphenols present in cranberry, fruit with potential antioxidant and anti-inflammatory effects. This clinical trial focuses on evaluating the effects of supplementation with a dry extract of cranberry on plasma levels of LPS and uremic toxins in non-dialysis CKD patients. METHODS: It was a randomized, double-blind, placebo-controlled study. Patients were randomized into two groups: the cranberry group received 500 mg of dry cranberry extract (2 times daily), and the placebo group received 500 mg of corn starch (2 times daily) for two months. LPS plasma levels were evaluated by enzyme-linked immunosorbent assay (ELISA) and uremic toxins (IS, p-CS, and IAA) by high-performance liquid chromatography-fluorescence detection. Anthropometric measurements and food intake using the 24-h food recall technique were also evaluated before and after the intervention. RESULTS: Twenty-five participants completed two months of supplementation: 12 patients in the cranberry group (8 women, 56.7 ± 7.5 years, estimated glomerular filtration rate (eGFR) of 39.2 ± 21.9 mL/min); 13 patients in the placebo group (9 women, 58.8 ± 5.1 years, eGFR of 39.7 ± 12.9 mL/min). As expected, there was a negative association between glomerular filtration rate and p-CS and IS plasma levels at the baseline. No change was observed in the uremic toxins and LPS levels. CONCLUSION: Cranberry dry extract supplementation for two months did not reduce the LPS and uremic toxins plasma levels produced by the gut microbiota in non-dialysis CKD patients.

Flavonoids and proanthocyanidins-rich fractions from Eugenia dysenterica fruits and leaves inhibit the formation of advanced glycation end-products and the activities of α-amylase and α-glucosidase.

ETHNOPHARMACOLOGICAL RELEVANCE: Different parts of Eugenia dysenterica have been popularly used in Brazil for treating diabetes mellitus and its complications. The present study aimed to screen extracts from E. dysenterica fruit pulp, peel, seed and leaf for carbohydrate digestive enzymes inhibitors with antioxidant and anti-glycation capacities. MATERIALS AND METHODS: Ethanol extracts of E. dysenterica were subjected to a liquid-liquid fractionation and the fractions were used to evaluate their antioxidant properties and inhibitory potential against the formation of advanced glycation end-products (AGEs) and α-amylase and α-glucosidase. RESULTS: The ethyl acetate fraction (EtOAcF) from seed and the dichloromethane fraction (CH2Cl2F) and EtOAcF from leaf had high antioxidant capacities (ORAC >5500 µmol trolox eq g-1, FRAP >1500 µmol trolox eq g-1 and DPPH IC50 < 35 µg mL-1) and showed exceptional inhibitory activities against AGEs formation (glycation inhibition above 80% at 10 µg mL-1) and α-amylase and α-glucosidase (inhibition above 50% at 10 µg mL-1). The gallated B-types proanthocyanidins were the most active ingredients found in the leaf of E. dysenterica (CH2Cl2 and EtOAcF), being responsible for the notorious inhibitory effects against glycation and glycoside hydrolases due to their ortho-hydroxyl groups, which play role in scavenge and quench free radicals and glycated products, and may occupy the enzymes' substrate binding pocket. Furthermore, gallic acid, quercetin and its glycoside derivatives were detected by the first time in the E. dysenterica fruit seed (EtOAcF). CONCLUSIONS: The results strongly contribute to the understanding of the antidiabetic potential of seeds and leaves from E. dysenterica, a species from a global biodiversity hotspot, which appears to be linked to the prevention of oxidative stress, AGEs production and postprandial hyperglycemia.

Interference of dietary polyphenols with potentially toxic amino acid metabolites derived from the colonic microbiota.

Each day, varying amounts of undigested or partially digested proteins reach the colon where they are metabolized by the microbiota, resulting in the formation of compounds such as ammonia, p-cresol, skatole, phenol, indole, and hydrogen sulfide (H2S). In farm animals, the excessive production of these metabolites can affect the quality of meat and milk and is a source of contaminating emissions from animal manure. In humans, their accumulation is potentially harmful, and it has been proposed that they could be involved in the development of pathologies such as colorectal cancer and ulcerative colitis, among others. This review assesses the evidence supporting the use of dietary polyphenols to reduce the production of these metabolites. Most studies have used condensed (proanthocyanidins) or hydrolyzable (ellagitannins and gallotannins) tannins, and have been carried out in farm animals. Several show that the administration of tannins in pigs, chicken, and ruminants decreases the levels of ammonia, p-cresol, skatole, and/or H2S, improving meat/milk quality and reducing manure odor. Direct application of tannins to manure also decreases ammonia emissions. Few studies were carried out in rats and humans and their results confirm, to a lesser extent, those reported in farm animals. These effects would be due to the capacity of tannins to trap ammonia and H2S, and to modify the composition of the microbiota, reducing the bacterial populations producing metabolites. In addition, PACs prevent p-cresol and H2S-induced alterations on intestinal cells in vitro. Tannins, therefore, appear as an interesting tool for improving the quality of animal products, human health, and the harmful emissions associated with breeding.

α-Glucosidase inhibitory phenolics from Echeveria subrigida (B. L. Rob & Seaton) leaves.

Echeveria subrigida is native to Mexico and its methanol extract (ME) shows relevant biological activities for human health, including the α-glucosidase inhibitory (αGI) activity that suggests its antidiabetic potential. Fractionation of the ME based on the αGI activity (IC50 in µg/mL) showed that quercetin-3-O-ß-glucoside (131.1), isorhamnetin-3-O-ß-glucoside (166.4), and dimers to heptamers proanthocyanidins (9.6) were among the main responsible of αGI activity in the ME. The purified compounds showed better activity than acarbose (IC50 = 4426 µg/mL).

In vitro antimicrobial activity of Douro wines against clinical Helicobacter pylori strains / strains121In vitro antimicrobial activity of Douro wines against clinical helicobacter pylori strains / Actividad antimicrobiana in vitro de los vinos del Duero sobre cepas clínicas de Helicobacter pylori

Abstract Aim. In vitro antimicrobial activities of seven wines (5 reds and 2 whites) from the Douro region (Iberian Peninsule) against eleven clinical strains of Helicobacter pylori were evaluated. Methods. The disk diffusion method, using Columbia Agar supplemented with horse blood (CAB), were used to determine the antimicrobial properties of some wine components against H. pylori strains. Potential interactions of antioxidants contained in the wines and two antimicrobials (amoxicillin and metronidazole) were studied by the disk diffusion method. Results. All the tested strains showed growth in CAB supplemented with 9% of the tested wines but none of them grew in media supplemented with 45% and 67.5% of wine. Similarly, all the tested strains grew in media with the concentration of proanthocyanidins present in the different types of the studied wines. The Minimal Inhibitory Concentration (MIC) values of the wine antioxidant components tested (benzoic acid, catechin, quercetin, and resveratrol) indicate that resveratrol was the most powerful inhibitory substance against H. pylori. An effect of potentiation between amoxicillin and metronidazole and the antioxidants tested was also established. The interaction of amoxicillin and resveratrol or metronidazole and catechin increased the antimicrobial activity against H. pylori. Conclusions. The results obtained suggested a potential role of resveratrol as a chemopreventive agent for H. pylori infection.

Resumen Objetivo. Se evaluó las actividades antimicrobianas in vitro de siete vinos (5 tintos y 2 blancos) de la región del Duero (Peninsula Ibérica) frente a once cepas de Helicobacter pylori de origen clínico. Métodos. Para determinar las propiedades antimicrobianas de algunos componentes del vino sobre las cepas de H. pylori se utilizaron las técnicas de difusión en disco en placas de agar Columbia suplementado con sangre de caballo (CAB). La potential interacción entre las sustancias antioxidantes presentes en los vinos y dos antimicrobianos (amoxicilina y metronidazol) se determinó usando la técnica de difusión en disco. Resultados. Todas las cepas ensayadas mostraron crecimiento en CAB suplementado con el 9% de los vinos analizados, pero no se obtuvo crecimiento de ninguna de las cepas en medios suplementados con el 45% y el 67,5% de vino. Asimismo, todas las cepas ensayadas crecieron en medios con la concentración de proantocianidinas presentes en los diferentes tipos de vinos estudiados. Los valores de concentración mínima inhibitoria (CMI) de los componentes antioxidantes de los vinos ensayados (ácido benzoico, catequina, quercetina y resveratrol) indican que el resveratrol fue la sustancia más potente en la inhibición del crecimiento de H. pylori. También se estableció un efecto de potenciación entre amoxicilina y metronidazol y los antioxidantes ensayados. Las interacciones amoxicilina + resveratrol y metronidazol + catequina aumentaron la actividad antimicrobiana contra H. pylori. Conclusiones. Los resultados obtenidos sugieren un papel potencial del resveratrol como agente quimiopreventivo de la infección por H. pylori.

Açaí (Euterpe oleracea Mart.) Seed Extracts from Different Varieties: A Source of Proanthocyanidins and Eco-Friendly Corrosion Inhibition Activity.

Euterpe oleracea Mart. (Arecaceae) is an endogenous palm tree from the Amazon region. Its seeds correspond to 85% of the fruit's weight, a primary solid residue generated from pulp production, the accumulation of which represents a potential source of pollution and environmental problems. As such, this work aimed to quantify and determine the phytochemical composition of E. oleracea Mart. seeds from purple, white, and BRS-Pará açaí varieties using established analytical methods and also to evaluate it as an eco-friendly corrosion inhibitor. The proanthocyanidin quantification (n-butanol/hydrochloric acid assay) between varieties was 6.4-22.4 (w/w)/dry matter. Extract characterization showed that all varieties are composed of B-type procyanidin with a high mean degree of polymerization (mDP ≥ 10) by different analytical methodologies to ensure the results. The purple açaí extract, which presented 22.4% (w/w) proanthocyanidins/dry matter, was tested against corrosion of carbon steel AISI 1020 in neutral pH. The crude extract (1.0 g/L) was effective in controlling corrosion on the metal surface for 24 h. Our results demonstrated that the extracts rich in polymeric procyanidins obtained from industrial açaí waste could be used to inhibit carbon steel AISI 1020 in neutral pH as an abundant, inexpensive, and green source of corrosion inhibitor.

Influência do uso da proantocianidina em um adesivo autocondicionante: avaliação da resistência de união / Influence of the use of proanthocyanidinin a self-etching adhesive: evaluation of bond strength / Influenciadel uso de proantocianidinaem um adesivo autograbante: evaluación de la fuerza de unión

Introdução:Os sistemas adesivos possibilitama execução de restaurações estéticas e minimamente invasivas, sendo, portanto,objeto de pesquisas para contornar os problemas que se apresentam no procedimento restaurador.Objetivo:Avaliar in vitroa resistência de união de um sistema adesivo autocondicionante, e deste modificado com soluções extrativas de semente de uva.Metodologia:Duas soluções extrativas foram preparadas comextrato de semente de uva em pó dissolvido em acetona e etanol. A partir delas e de umadesivo,seis sistemas adesivos autocondicionantes experimentais foram preparados, diferindo quanto aosolvente utilizado eàsproporções entre adesivo puro e solução extrativa(7,5%, 15% e 30%). Setenta incisivos bovinos hígidos tiveram as raízes removidas com disco de carborundum e as faces vestibulares desgastadas comlixas d'água de granulação 120, 240, 600 e 1200 sob refrigeração até expor a dentina superficial. Os dentes foram distribuídos aleatoriamenteem sete grupos distintos: Controle; A7,5; A15; A30; E7,5; E15; e E30, contendo 10 elementos cada. A aplicação dos adesivos foi executada de acordo com as recomendações do fabricante do adesivo controle. A restauração foi realizada com uma matriz de silicone com dimensões 2mm de altura e 4mm de diâmetro e inserido o material restaurador em incremento único e fotopolimerizado por 40s. Após três meses armazenados em água destilada, os espécimes foram submetidos ao teste de resistência de união. Foi empregado ométodo estatísticoTeste Paramétrico Anova 1 Fator e pós-teste de Tamhane (p<0,05). Resultados:Os grupos A7,5, E7,5 e E30 não apresentaram diferença em relação ao grupo Controle; A15 e A30 mostraram desempenho estatisticamente semelhante entre si; e E15 não apresentou diferença estatística em relação aos outros adesivos.Conclusões:A adição de proantocianidina teve efeitos diferentes,dependendodos solventes e das concentrações utilizadas, mas sem alterar significativamente o desempenho do adesivo (AU).

Introduction:Adhesive systems make it possible to perform aestheticand minimally invasive restorations, being the subject of research to circumvent the problems that arise in the restorative procedure.Objective:Evaluate in vitrothe bond strength of a self-etching adhesive system,and modified with extractive grape seed solutions. Methodology:Two extractive solutions were prepared with powdered grape seed extract dissolved in acetone and ethanol. From them and an adhesive, six experimental self-etching adhesive systems were prepared, differing in terms of the solvent used and the proportions between pure adhesive and extractive solution(7.5%, 15% and 30%). Seventy healthy bovine incisors had their roots removed with carborundum disc and the vestibular faces were worn with sandpaper with granulation water 120, 240, 600 and 1200 under refrigeration until the superficial dentin was exposed. The teeth were randomly assigned to seven different groups: Control; A7.5; A15; A30; E7.5; E15; and E30, containing 10 elements each. The application of the adhesives was carried out according to the recommendations of the manufacturer of the control adhesive. The restoration was performed with a silicone matrix with dimensions 2mm high and 4mm indiameter and the restorative material was inserted in a single increment and light cured for 40s. After three months stored in distilled water, the specimens were submitted to the bond strength test. The statistical method Parametric Test Anova 1 Factor and Tamhane post-test (p<0.05) were used. Results:Groups A7.5, E7.5 and E30 showed no difference in relation to the Control group; A15 and A30 showed a statistically similar performance; and E15 showed no statistical difference in relation to the other adhesives. Conclusions:The addition of proanthocyanidin had different effects, depending on the solvents and concentrations used, but without significantly altering the performance ofthe adhesive (AU).

Introducción: Sistemas adhesivos permiten realizar restauraciones estéticas y mínimamente invasivas, siendo objeto de investigación para sortear problemas que surgen en elprocedimiento restaurador. Objetivo: Evaluar in vitrola fuerza de unión de un sistema adhesivoautograbante y modificado con soluciones extractivas de semilla de uva. Metodología: Se prepararon dos soluciones extractivas con extracto de semilla de uva en polvo disuelto en acetona y etanol. A partir de ellos y de un adhesivo, se prepararon seis sistemas experimentales de adhesivos autograbantes, que se diferencian en cuanto al solvente utilizado y las proporciones entre adhesivo puro y solución extractiva (7,5%, 15% y 30%). Setenta incisivos bovinos sanos fueron removidos con un disco de carborundo y las caras vestibulares fueron usadas com lija de agua de granulación 120, 240, 600 y 1200 bajo refrigeración hasta que la dentina superficial quedo expuesta. Los dientes se asignaron aleatoriamente a siete grupos diferentes: Control; A7,5; A15; A30; E7,5; E15; y E30, que contiene 10 elementos cada uno. La aplicación de los adhesivos se realizó siguiendo las recomendaciones del fabricante del adhesivo de control. La restauración se realizó con matriz de silicona con 2mm de altura y 4mm de diámetro y el material restaurador se insertó en un solo incremento y se fotopolimerizó durante 40s. Tres meses después, almacenados em agua destilada, las muestras se sometieron a la prueba de resistencia de la unión. Se utilizó el método estadístico Prueba Paramétrica Factor Anova 1 y post-prueba de Tamhane (p<0,05). Resultados: Los grupos A7,5, E7,5 y E30 no mostraron diferencias em relación con el grupo Control; A15 y A30 mostraron un desempeño estadísticamente similar; y E15 no mostró diferencia estadística en relación con los otros adhesivos. Conclusiones: La adición de proantocianidina tuvo diferentes efectos, dependiendo de los disolventes y concentraciones utilizadas, pero sin alterar significativamente el rendimiento del adhesivo (AU).

Seed tannin composition of tropical plants.

Seeds collected from trees, shrubs and lianas growing on Barro Colorado Island, Panama, were analyzed for their content of phenolic compounds, oxidative activities and protein precipitation capacities. Proanthocyanidins and hydrolysable tannins were detected in one-third of 189 studied species. The most oxidatively active group of species were the ones containing prodelphinidins and ellagitannins whereas the species that had the highest protein precipitation capacity in relation to their total phenolics were the ones containing punicalagin. In addition, the oxidative activity and relative protein precipitation capacity were exceptionally high in the proanthocyanidin-rich genus Psychotria. This study offers a comprehensive overview on the tannin composition and the alkaline oxidative activities and protein precipitation capacities of the seeds of tropical plants.

TNF-α inhibition, antioxidant effects and chemical analysis of extracts and fraction from Brazilian guaraná seed powder.

Paullinia cupana Kunth., commonly named Guaraná, is a plant from Brazil used as stimulant. The aim of this study was to evaluate the potential of extracts and tannins-rich and methylxanthines-free fraction from guaraná in the anti-inflammatory and antioxidant effect in vitro. Extract 1 obtained good yields of tannins and methylxanthines and was used to identify a type-A procyanidin trimer by LC-ESI-MS. Fraction 4 was rich in tannins and absent of methylxanthines. The extracts and fraction exhibited strong capacity for scavenging DPPH radical with IC50 between 5.88 and 42.75-µg/mL and inhibited TNF-α release by LPS-activated THP-1 cells when compared with control cells and did not present toxicity to THP-1 cells. The fraction 4, rich in tannins, was highly active, with IC50 5.88 µg/mL by DPPH method and inhibited TNF-α release in 83.50% at 90 µg/mL. These results reinforced potential anti-inflammatory of guaraná and data for new therapeutic approaches.

Hypotensive activity of Campomanesia xanthocarpa leaf extract: beyond angiotensin II type 1 receptor blockage.

The ability of Campomanesia xanthocarpa leaf extract (CXLE) to alter blood pressure and heart rate was evaluated in anesthetized rats. The CXLE-induced hypotension was evaluated before and after losartan, methylatropine, L-N(ω)-nitro-L-arginine methyl ester (L-NAME), hexamethonium, indomethacin, glibenclamide, or nifedipine administration. The constituents of CXLE were identified by LC-DAD-MS. CXLE decreased blood pressure in a dose-dependent manner; only the highest dose decreased heart rate. The hypotension induced by CXLE was sensitive only to losartan, nifedipine, and glibenclamide. L-NAME decreased the time to recover 50% of the hypotensive effect of CXLE without altering its magnitude. Flavan-3-ols, proanthocyanidins (dimers and trimers), and glycosylated flavonols were identified from CXLE. The chemical constituents of CXLE seem to induce not only angiotensin II type 1 receptor blockage, but also ATP-sensitive potassium channels activation and L-type voltage-dependent Ca2+ channels inactivation. Nitric oxide is involved in the maintenance of the hypotensive effect of CXLE.

Effect of dentin biomodification delivered by experimental acidic and neutral primers on resin adhesion.

OBJECTIVES: Proanthocyanidins (PACs) are biocompounds mimicking native collagen cross-links. The effective and practical delivery of any biocompound is pivotal for clinical usage. The aim was to investigate the dentin biomodification and effective formation of dentin-resin biointerfaces of two highly bioactive PAC-rich extracts, Vitis vinifera (Vv) and Camellia sinensis (Cs), delivered using neutral (NP) or acidic (AP) rinse-out primer approaches. METHODS: The depth of dentin demineralization (optical profilometry), dentin biomodification (apparent modulus of elasticity, collagen auto-fluorescence) and properties of dentin-resin interfaces (microtensile bond strength - µTBS, and micro-permeability) were investigated. NP consisted of either 15% Vv or Cs applied for 60 s after surface etching; while AP contained 15% Vv or Cs in either 35% glycolic acid or tartaric acid applied for 30 s or 60 s. Data were analyzed using ANOVA and post-hoc tests (α = 0.05). RESULTS: The depth of demineralization was statistically higher when applied for 60 s, regardless of rinse-out primer approach (p < 0.001). Compared to the AP strategy, NP exhibited statistically higher apparent modulus of elasticity, regardless of PAC extract (p < 0.001). Highest µTBS were obtained for NPVv, which were statistically similar to APGAVv, when applied for 60 s (p < 0.001); both resulted in a dramatic decrease of the interfacial permeability. NPCs group showed the lowest µTBS (p < 0.001). CONCLUSIONS: A combination of high bond strength and low micro-permeability can be accomplished using glycolic acid with the mid- and high-PAC oligomer enriched extract (Vv). Cs extract containing mostly catechins and dimeric PACs, was found unsuitable for resin-dentin adhesion despite exhibiting high initial dentin biomodification. CLINICAL SIGNIFICANCE: This study provides a new conceptual delivery of PAC-mediated dentin biomodification and conservative dentin surface etching using rinse-out primers. The strategy requires a specific combination of PAC source, α-hydroxy acid, and application time.

Insoluble-Bound Polyphenols Released from Guarana Powder: Inhibition of Alpha-Glucosidase and Proanthocyanidin Profile.

The Brazilian Food Supplement Law recently recognized that guarana (Paullinia cupana) contains bioactive substances, hence supporting its role as a functional food ingredient. The health benefits of guarana are associated, at least in part, to its phenolic compounds. However, to the best of our knowledge, there is no literature addressing the presence of phenolic compounds in the fraction containing insoluble-bound compounds and its contribution in terms of alpha-glucosidase inhibition. The concentration of phenolic extracts released from the insoluble-bound fraction required to inhibit 50% of alpha-glucosidase (IC50) activity was 5.8-fold lower than that present in the soluble counterpart. Both fractions exhibited a mixed inhibition mode. Fourteen proanthocyanidins (dimers to tetramers) present in the insoluble-bound fraction were tentatively identified by MALDi-TOF-MS. Future studies aiming at increasing the concentration of the soluble counterpart are deemed necessary. The results presented here enhance the phenolic database of guarana and have a practical impact on the procurement of nutraceuticals and functional ingredients related to the prevention and/or management of type 2 diabetes. The Brazilian normative on food supplements has been recently revised. This study lends support to the future inclusion of guarana powder in the list of sources of proanthocyanidins for the industry of food supplements.