Liposomal and chitosan-coated liposomal nanocarriers for grape seed proanthocyanidins: Integrated physicochemical, cellular, and rheological characterization.

Introduction. Dietary fiber is an essential nutritional component, which, its modulating action on gut microbiota must be outlined. The consumption of foods of vegetable origin, and therefore, the dietary´s fiber consumption, in Spain, as well as in some other countries, has been reduced. Functional foods have been found to be a great food alternative to solve this dietary deficiency.\n
\n\nObjectives. 1. To review dietary´s fiber concept. 2. To get to know the real consumption situation of dietary fiber in Spain, in other European countries; in different age groups. 3. To study the main effects related to dietary fiber consumption, particularly the effects of proanthocyanidins (PA) with respect to the gut microbiome. 4. To revise functional foods concept, and the possibilities of incorporating dietary fiber and PA into different highly consumed foods.\n
\n\nMaterials and methods. The main research support has been the PubMed database, although it has also been used Google Scholar, ResearchGate and SciELO. At the same time scientific articles, books and reports from reliable and corroborated sources have been revised. In addition, official documents have been consulted, as the 2018 Spanish Foods Consumption Report, published by the Spanish Ministry of Agricultura, Pesca y Alimentación; the AESAN website, and the current food regulations.\n
\n\nResults. It is proved that the real dietary fiber intakes in different European countries, including in Spain, are far below the dietary reference intakes (DRI), in most of the studied age ranges. In this article, there are proposed strategies to achieve these DRI, particularly adding dietary fiber into highly consumed foods (i.e. meat matrices). The concept of functional foods is reviewed, and some of the most relevant publications reporting the effects of PA in relationship to the gut microbiome recovery, and its change to another related to the healthy people´s microbiome. The mechanisms by which the gut microbiome is able to hydrolyse the PA, and consequently release metabolites with gut and systemic protective activity, is also discussed.\n
\n\nConclusions. Given that modifying the population consumption habits seems a difficult task, the alternative of formulating functional foods enriched with dietary fiber and PA it is suggested. The increasing positive evidence observed derived from the consumption of functional meat products to which carob fruit fiber has been added, suggests the relevance of continuing investigating in this field, and therefore start the formulation of new functional foods (i.e. cereals, creams, sweets, etc.) enriched with this PA-enriched fiber, which would lead to an adequate dietary fiber consumption and the benefits from its functional functions.

Effects of grape variety and roasting on the proanthocyanidin oligomers distribution, cyclic proanthocyanidins, and total polyphenol content in grape seed powders

Proanthocyanidins (PACs) are naturally occurring polyphenolic compounds abundantly present in grape seeds and are widely recognized for their antioxidant and antimicrobial properties. This study aimed to extract, purify, characterize, and evaluate the biological activity of PACs derived from grape seeds, as well as to investigate their potential application as a radiolabeled imaging agent for bacterial inflammation. PACs were extracted and purified, via thin-layer chromatography (TLC). And confirming the presence of functional groups characteristic of condensed tannins using FTIR. The in vitro antimicrobial activity of PACs was evaluated against selected G+ve and G-ve bacterial strains, as well as fungal strains, using disc diffusion method. The results demonstrated strong inhibitory activity against E.coli and S.aureus, while moderate to mild inhibition was observed against other bacterial strains and fungal strains. The total phenolic content (TPC) and total flavan-3-ol content (TFC) were determined using the Folin–Ciocalteu and vanillin assays, yielding values of 435 mg GAE/g and 283 mg CE/g, respectively. Antioxidant activity assessed by the DPPH radical scavenging assay showed a high scavenging capacity of 91.75%. Furthermore, PACs were successfully radiolabeled with technetium-99m (⁹⁹ᵐTc) to form a novel ⁹⁹ᵐTc–PACs complex, achieving an optimized radiochemical yield of 85.6 ± 0.5%. In vivo biodistribution studies in a mouse model of bacterial infection demonstrated preferential accumulation of the radiolabeled complex at sites of inflammation, along with rapid blood clearance and renal excretion. These findings support the potential of ⁹⁹ᵐTc–PACs as a promising radiotracer for non-invasive imaging of bacterial inflammation.

This study employed UPLC-MS/MS to determine the contents of major polyphenolic compounds and proanthocyanidins (PCs) in Kyoho grape seeds, optimized the extraction method and conditions for PCs using response surface methodology (RSM), and further evaluated the scavenging activities of PCs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (•OH) radicals as well as their effects on growth, immunity, and oxidative stress in mice. Three hundred and sixty 3-week-old male mice (42.28 ± 0.31 g) were assigned to a single factor complete randomized trial design and fed with six different diets including 0 mg/kg vitamin E(VE) + 0 mg/kg PCs, 100 mg/kg VE, 25 mg/kg PCs + 75 mg/kg VE, 50 mg/kg PCs + 50 mg/kg VE, 75 mg/kg PCs + 25 mg/kg VE and 100 mg/kg PCs, respectively. The results demonstrated that PCs were identified as the predominant phenolic compounds, accounting for 29.6% of total phenolic substances in Kyoho grape seeds. Additionally, the ultrasound-assisted extraction method was superior to the shaker-assisted and low-temperature infiltration extraction methods, with optimal conditions of 60% ethanol concentration, material-to-liquid ratio of 1:20 g/mL, temperature of 30 °C, and extraction time of 50 min. Scanning electron microscopy (SEM) revealed that ultrasound treatment effectively disrupted the seed surface structure, facilitating PC release. In vitro, PCs exhibited significantly stronger DPPH and hydroxyl radical (•OH) scavenging activities than vitamin C (VC), Trolox, and gallic acid. Compared with the control group, mice fed diets containing PCs and VE showed higher superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-PX) activity, and total antioxidant capacity (TAOC), Catalase (CAT), GPX and inflammation factor 10 (IL-10) genes levels in the serum and liver (p < 0.05), whereas the levels of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), as well as the mRNA expression of IL-1β and TNF-α, showed the opposite trend (p < 0.05). In conclusion, the antioxidant capacity of PCs was stronger than that of VC and VE. The addition of PCs improved the antioxidant activity and immune function of mice.

Grape seed extract (GSE) is a rich source of condensed flavonoid tannins, also called proanthocyanidins (PACs). The high molecular weight of polymeric PAC limits their biological activity due to poor bioavailability. The present study was undertaken to explore the potential applicability of microwave-assisted extraction (MAE) to convert GSE-PAC into monomeric catechins. A central composite design (CCD) was used to optimize the processing conditions for the MAE. The maximum total yield of monomeric catechins (catechin, epicatechin, and epicatechin gallate) and PAC were 8.2 mg/g dry weight (DW) and 56.4 mg catechin equivalence (CE)/g DW, respectively. The optimized MAE condition was 94% ethanol, 170 °C temperature, and a duration of 55 min. Compared to the results for PACs extracted via conventional extraction (Con) (94% ethanol; shaking at 25 °C for 55 min), MAE yielded 3.9-fold more monomeric catechins and 5.5-fold more PACs. The MAE showed higher antioxidant capacity and α-glucosidase inhibitory activity than that of the conventional extract, suggesting the potential use of the MAE products of grape seeds as a functional food ingredient and nutraceutical.

Flavonoids and proanthocyanidins (PACs) have been the subject of intense scientific investigations, both for their antioxidant properties and anti-adhesion activity against uropathogenic bacteria. We investigated the metabolomics and antioxidant capacity of SP4TM, a patent-pending formulation based on a mixture of plant extracts with a high content of bioactive PACs and other polyphenols. The total content of polyphenols (885.51 ± 14.19 mg/g), flavonoids (135.52 ± 8.98 mg/g), anthocyanins (54.84 ± 2.97 mg/g), and PACs (379.43 ± 12.44 mg/g) was quantified using UV-Vis assays. Use of HPLC-ESI-MS/MS revealed the presence of 5 flavanols (100.77 ± 3.90 mg g−1 d.wt), 11 flavonols (59.96 ± 1.83 mg g−1 d.wt), and 8 anthocyanins (46.96 ± 1.59 mg g−1 d.wt), whereas MALDI-TOF MS showed that SP4TM contains PACs with one or more type-A interflavan bonds at each degree of polymerization. Regarding antioxidant properties, LUCS technology on HepG2 cells evidenced the ability of SP4TM to neutralize intracellular free radicals, inhibit membrane lipid peroxidation, quench H2O2, and reduce free radicals mainly through chelating mechanism, as demonstrated by a higher FRAP value (2643.28 ± 39.86 mmol/g) compared with ABTS (139.92 ± 6.16 mmol/g) and DPPH (89.51 ± 3.91 mmol/g). Finally, the SP4TM type-A PAC content strongly prevented bacterial adhesion of P-fimbriated uropathogenic Escherichia coli (0.23 mg/mL). In conclusion, SP4TM has a strong antioxidant capacity involving multitarget mechanisms and is a potential supplement to fight urinary tract infections due to its ability to inhibit uropathogenic E. coli adhesion.

Aims and backgroundEarly dental caries are caused by subsurface demineralization of enamel and manifests 0.0015 as noncavitated, white lesions. Remineralization is a process that replaces lost mineral ions in demineralized enamel. Saliva naturally aids in remineralization. However, this process is slow and can be hampered under cariogenic conditions. Fluoride has been a significant caries—preventive agent, promoting remineralization, and preventing demineralization. However, interest in non-fluoridated treatments has increased due to concerns about dental fluorosis. Proanthocyanidins (PACs), which are extracted from grape seeds, have remineralization potential owing to their capacity to chelate calcium and phosphate ions.Materials and methodsThis study examined the remineralization effectiveness of a fluoride varnish and a PAC biovarnish on artificially induced dental caries in vitro. Grape seeds were used to extract PACs to create a biovarnish. Three groups of 60 primary molar teeth each—control (no treatment), fluoride varnish, and PAC varnish—were used. The sample tooth was immersed in a demineralizing solution for 4 days to produce artificial caries lesions. Remineralization treatments were administered twice a day for 7 days after demineralization. Changes in surface topography and enamel hardness were evaluated by scanning electron microscopy (SEM) and Vickers enamel microhardness testing (VEMH).ResultsOne-way ANOVA (analysis of variance) revealed significant differences (p = 0.00) after remineralization, with the PAC varnish group showing the highest (VEMH) values. SEM analysis showed effective remineralization with PAC varnish, presenting a surface similar to sound enamel.ConclusionThe novel PAC biovarnish demonstrated superior remineralization efficacy compared with fluoride varnish, suggesting it as a promising alternative for fluoridated caries prevention treatments.Clinical significanceThe study demonstrates that PAC biovarnish is a highly effective alternative to fluoride varnish for enamel remineralization, potentially reducing the risk of dental fluorosis. This offers a promising nonfluoridated option for caries prevention and management.How to cite this articleBaskar R, Srinivasan D, Eagappan AR S, et al. Comparative Evaluation of Remineralization Efficacy of a Novel Proanthocyanidin Biovarnish with Fluoride Varnish on Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2025;18(10):1187–1193.

BackgroundHawthorn is the common name of all plant species in the genus Crataegus, which belongs to the Rosaceae family. Crataegus are considered useful medicinal plants because of their high content of proanthocyanidins (PAs) and other related compounds. To improve PAs production in Crataegus tissues, the sequences of genes encoding PAs biosynthetic enzymes are required.FindingsDifferent bioinformatics tools, including BLAST, multiple sequence alignment and alignment PCR analysis were used to design primers suitable for the amplification of DNA fragments from 10 candidate genes encoding enzymes involved in PAs biosynthesis in C. aronia. DNA sequencing results proved the utility of the designed primers. The primers were used successfully to amplify DNA fragments of different PAs biosynthesis genes in different Rosaceae plants.ConclusionTo the best of our knowledge, this is the first use of the alignment PCR approach to isolate DNA sequences encoding PAs biosynthetic enzymes in Rosaceae plants.

Metabolic and RNA profiling elucidates proanthocyanidins accumulation in Aglianico grape

Inhibition of the angiotensin-converting enzyme by grape seed and skin proanthocyanidins extracted from Vitis vinífera L. cv. País

A galloylated dimeric proanthocyanidin from grape seed exhibits dentin biomodification potential

Grape seeds are a copious part of the grape pomace produced by wine and juice industry and they represent an interesting source of phenolic compounds. Proanthocyanidins (PAs) are the main class of grape seed phenols and are important dietary supplements for their well-known beneficial properties. In this study enriched extracts obtained from Chardonnay and Pignoletto grape seeds were characterized for their proanthocyanidins and other minor phenolic compounds content and composition. Seed PAs were fractionated using Sephadex LH-20, using different ethanol aqueous solutions as mobile phase and analysed by normal phase HPLC-FLD-ESI-MS. Monomers, oligomers up to dodecamers and polymers were recorded in all samples. For both cultivars, the extracts showed a high content in PAs. The determination of other phenolic compounds was carried out using a HPLC-QqQ-ESI-MS and Chardonnay samples reported a greater content compared to Pignoletto samples. Contrary to PAs fraction, extracts obtained with ethanol/water 50/50 (v/v) presented a significant higher phenolic content than the others.

Two proanthocyanidin (PA) fractions, one (Sdp3) with the mean degree of polymerization (mDP) of 3 and the other (Sdp9) with mDP of 9, were obtained from a Vitis vinifera cv. Shiraz grape seed extract. The PA fractions were directly analyzed by electrospray ionization mass spectrometry (ES-MS) and negative ion mass spectra were recorded. The mass spectrum of Sdp3 exhibited only singly charged ions corresponding to the molecular mass of PA with a degree of polymerization (DP) up to 9 (nonamers). In contrast, Sdp9 yielded rather complex mass spectra featuring ions with single [M - H](-), double [M - 2H](2-) and triple [M - 3H](3-) charge representing the molecular masses of PAs up to a DP of 28. In addition, the degree of galloylation per procyanidin (DG) was observed to be up to 5 (pentagallates) in Sdp3 and 8 (octagallates) in the Sdp9. This is the first evidence obtained by mass spectrometry for the distribution of grape seed PAs with such a high degree of polymerization and a broad diversity of galloylation. ES-MS data together with the complementary information provided by acid hydrolysis provides a detailed picture of the composition of grape seed PAs.

Centrifugal partition chromatography enables selective enrichment of trimeric and tetrameric proanthocyanidins for biomaterial development

Proanthocyanidins (PAs) derived from the grape skin, as well as from grape seeds, grape stems, are an important group of polyphenols in wine. The aim of this study was to understand the effect of PAs (0.1, 1.0 g/L) on growth and alcoholic fermentation of 2 strains of Saccharomyces cerevisiae (commercial strain FREDDO and newly selected strain BH8) during copper-stress fermentation, using a simple model fermentation system. Our results showed that both PAs and Cu(2+) could pose significant inhibition effects on the growth of yeast cells, CO2 release, sugar consumption, and ethanol production during the initial phase of the fermentation. Compared to PAs, Cu(2+) performed more obvious inhibition on the yeast growth and fermentation. However, adding 1.0 g/L PAs increased in the vitality and metabolism activity of yeast cells at the mid-exponential phase of fermentation in the mediums with no copper and 0.1 mM Cu(2+) added, shortened the period of wine fermentation, and decreased the copper residues. It indicated that PAs could improve the ability of wine yeast to resist detrimental effects under copper-stress fermentation condition, maintaining cells metabolic activity, and fermentation could be controlled by manipulating PAs supplementation.