Search Results (11)

Background/Objectives. Inflammation, comprising many complex and finely coordinated immunological processes, represents a vital protective mechanism of the human body. By regulating inflammatory processes, cytokines play a key role in the modulation of the immune system. Secondary plant compounds such as polyphenols influence cellular immunological processes which might contribute to ensuring a physiologically healthy immune status. Methods/Results. This study investigated eleven polyphenol-rich extracts from red fruit beverages in terms of potential inhibitory effects on pro-inflammatory cytokine secretion of leukemic monocyte THP-1 cells. Extracts originating from fruit juice (apple), fruit juice concentrate (red grape, black currant, pomegranate, elderberry, aronia), fruit juice puree (cranberry, blueberry) or fruit juice pulp (strawberry, sour cherry) were obtained by adsorption onto Amberlite^® XAD-7 resin. The Folin–Ciocalteu assay showed a high content of phenolic compounds in the eleven extracts and HPLC-DAD-ESI-MSⁿ analysis revealed that the extracts contained various anthocyanins in addition to copigments and polymers. Further screening using Lumit^® Immunoassay showed that all tested extracts caused a reduction in pro-inflammatory cytokine secretion (interleukins (IL): IL-1β, IL-6, IL-8 and tumor necrosis factor TNF-α). The extracts from red grape and black currant were the most active ones. Conclusions. Overall, our results showed that polyphenol-rich fruit extracts can inhibit inflammatory processes in vitro. In vivo studies on the anti-inflammatory effect of fruit juice will be a promising approach to determine the fruit juice-dependent, health-promoting effects in humans. Full article

SARS-CoV-2 main protease (M^pro) is essential for viral polyprotein processing and represents a prime target for antiviral drug discovery. However, most available screening strategies rely on computational predictions or cell-free biochemical approaches that provide limited functional context and often require specialized instrumentation, while mammalian cell-based models remain costly and require high biosafety levels. Accordingly, there remains a shortage of simple, rapid, and biosafe functional screening tools suitable for early-stage prioritization of potential M^pro inhibitors, particularly those derived from natural sources and in urgent situations such as the COVID-19 pandemic. In this study, a bacterial colorimetric reporter assay was developed that directly links SARS-CoV-2 M^pro activity to β-galactosidase function in Escherichia coli. To the best of our knowledge, the developed assay represents the first bacterial colorimetric model for functional detection of SARS-CoV-2 M^pro inhibition based on a phenotypic readout. The assay enables the rapid visual detection of protease inhibition on X-gal-containing medium and provides a cost-effective and biosafe platform for prioritizing candidate inhibitors, under standard laboratory conditions, prior to further validation. Due to its bacterial expression context, this assay is intended for functional screening to provide the most promising candidate compounds and/or extracts for subsequent biochemical or mammalian cell-based validation; it is not intended to determine quantitative potency or to replace further validation approaches. It should be noted that the selective compound uptake in E. coli restricts the range of chemical compositions that can be evaluated using this method. Therefore, proof-of-concept application was demonstrated using pomegranate juice, a representative natural inhibitor source, rather than most currently known specific M^pro inhibitors. In addition, other plant-derived preparations, including rhubarb, grape, and red/black currant juices, were tested demonstrating the assay’s applicability to diverse natural matrices. Full article

This study investigated the population dynamics of Vespa orientalis L. (Hymenoptera: Vespidae) across two consecutive seasons (2023–2024) in selected apiaries, with a focus on nest composition (eggs, larvae, and pupae) and the effectiveness of various bait traps for capturing the species. Monthly monitoring revealed the highest population peaks in October and the lowest in December. Notable inter-seasonal variations in population density were observed across the studied sites. The average number of individuals per nest varied between seasons, reflecting fluctuations in colony development and environmental factors. In 2023, the mean counts of cells, eggs, larvae, and pupae per nest were 30.14, 18.77, 13.33, and 20.88, respectively, while in 2024, they were 10.55, 14.81, 18.02, and 30.43. Among the tested attractants, grape juice proved the most effective, capturing an average of 511.67 hornets, followed by black honey (422.33 hornets), whereas the capturing trap caught only 5 hornets. These findings provide insights into the seasonal activity and reproductive status of V. orientalis and support the development of environmentally friendly capture strategies. Full article

As compared to red wine technology, where pomace is macerated, the grape juices and musts are obtained by pressing the grapes and removing the pomace, thus removing an important source of antioxidant molecules. The objective of this study was to exploit the bioactive compounds from the black grape pomace and obtain a new food product, namely pasteurized red must with improved health-promoting properties. The study was conducted on four grape varieties for red wines—Fetească Neagră, Cabernet Sauvignon, Blauer Zweigelt, and Arcaș—each coming from a certain recognized Romanian vineyard, as follows: Murfatlar, Dealu Mare, Ștefănești-Argeș, and Iași, respectively. Both the must and the pomace extract used for each product were from the same variety and region. The recovery of polyphenols was achieved by macerating the pomace at ambient temperature, using solutions of ethanol in concentrations of 25%, 50%, and 75%. The results showed that the most efficient method of polyphenol recovery was obtained by using the ethanolic solution of 50%, which was selected for the subsequent stages of the study. The selected hydroalcoholic extract was concentrated by eliminating the solvent by roto evaporation and used as a source of supplementary bioactive compounds for the pasteurized must. The phenolic profiles of the musts enriched with phenolic extracts were determined by liquid chromatography, UHPLS-HRMS, revealing significant increases in the content of individual phenolic acids and other polyphenols. The phenolic extract recovered from the pomace significantly optimized the phenolic quality of the pasteurized must, thus contributing to the improvement of its nutritional value. The new product has a phenolic profile close to that of a red wine, but does not contain alcohol. Also, this technology is a sustainable method to convert grape waste into a safe, antioxidant-rich grape juice with potential health benefits. Full article

In order to compare the grape juice sensory properties of four common seedless grape varieties (Kyoho, Summer Black, Moldovan, and Sweet Sapphire) in China, a thorough comparison of these grape varieties was conducted. Physicochemical indicators, aroma, and color characteristics were analyzed and compared to a commercially available not-from-concentrate Concord grape juice. The contents of fructose, glucose, and seven organic acids were evaluated. Kyoho and Sweet Sapphire possessed optimal Brix–acid ratio in the range around 35–40. In terms of aroma, 60 volatiles were identified by GC-MS, including 16 alcohols, 9 terpenes, 6 aldehydes, and 4 ketones. Kyoho demonstrated the highest aroma intensity with superior floral and fruity notes, while Sweet Sapphire showed the lowest aroma intensity with a grassy scent. Additionally, grape pigment profiles were investigated by HPLC-PDA-MS. Summer Black grapes featured a vibrant color, and 52.5% of their anthocyanins were acylated, which helps provide good stability in follow-up processing. Concord juice showed the best overall properties, with the most saturated color and delightful aroma. It was suggested that blending Summer Black with Kyoho could be a promising way to achieve balanced color, taste, and aroma of grape juice. This study provides a feasible and promising combination of Chinese local grapes for making all-round high-quality juice products. Full article

In this study, nutraceutical properties of fruit juice and seeds, which are important for human health, of green (Kabarcik, Cavus), red (red Globe) and black (Honusu, Yildiz, Yediveren and Helvani) skin colored grape cultivars grown in same ecological conditions were investigated. Harvest period, number of seeds, cluster form, cluster weight, berry weight, berry color and usage area were determined as morphological parameters. The Folin-Ciocalteu method was used for total phenol content analysis. The total antioxidant status of juices and seeds of grape cultivars have been determined by 2,2–diphenyl−1–picryl-hydrazyl–hydrate (DPPH), ferric reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays. Seeds of all grape cultivars exhibited higher nutraceuticals than fruit juices. Total phenolic content of seed samples was found to be quite variable in range of 1.90 mg GAE/g (cv. Yildiz)–3.46 mg GAE/g (cv. Honusu) fresh weight base (FW), indicating 2 folds of differences between green and black grape cultivars. Green and black cultivars also showed the lowest and the highest total phenolic content in juices between 1.69 (cv. Yediveren) and 2.45 (cv. Honusu mg GAE/g FW). Seeds and fruit juices of all cultivars analyzed showed high antioxidant capacity and total phenol content. Of all different colored cultivars, black peel-colored cultivars had the highest values and combined better morphological and nutraceutical traits with an excellent berry qualitative profile for cv. Honusu and Helvani. Full article

Grape production has a long history in the Elazig province and surrounding vicinity and produced grapes have been used for table consumption and also processed into traditional beverages, Şıra (special non-alcoholic grape juice) and wine. In the Elazig province, the main grape cultivars are ‘Ağın Beyazı’, ‘Öküzgözü’, ‘Boğazkere’, ‘Şilfoni’, ‘Tahannebi’, and ‘Köhnü’. Among them, ‘Köhnü’ cultivar is highly preferred by consumers due to its black color and perfect berry characteristics. The cultivar has grown for centuries in different parts of Elazig and shows a great variability for most of its morphological and biochemical characteristics. In the present study, we aimed to determine morphological and biochemical traits in six ‘Köhnü’ clones sampled from Elazığ. The cluster weight of six clones was found between 334–394 g. The highest total phenolic content was observed in seeds followed by peel and pulp samples. The seed extract of Clone 2 had the highest total phenolic content at 254 mg gallic acid equivalent/100 g fresh weight. The results also showed that peel, pulp, and seed samples of ‘Köhnü’ grape clones had considerable amounts of antioxidant components determined by DPPH (1,1-Diphenyl-2-picryl-hydrazyl), FRAP (ferric reducing antioxidant power), and TEAC assays and might be rich sources of natural antioxidants. Among the six ‘Köhnü’ clones, Clone 3, and Clone 6 differed from the others in respect to the highest cluster weight, the highest concentrations of total phenolic content, and antioxidant activity. The results also implied that all clones could be used potentially as a readily accessible source of natural antioxidants and as a possible pharmaceutical supplement. Full article

Fruits contain a number of useful substances including antioxidants. Their bio-accessibility after passing through the digestive tract is of primary importance when considering their benefits. In this respect, we investigated the effect of in vitro digestion on the phytochemicals of eight fruit juices. Freshly prepared juices from pomegranate, orange and grapefruit were used as well as commercially available juices from cherry, black grapes and aloe vera, blackberry and chokeberry, and two types of chokeberry and raspberries. Spectrophotometric and HPLC methods were used in order to analyse the sugar content, the total phenolic (TPC) and flavonoid contents (TFC), anthocyanins, phenolic acids and antioxidant activity. Principle component analysis was used to explain the differentiation among the types of fruit juice. Sugar recovery variation was between 4–41%. The bio-accessibility of TPC ranged from 13.52–26.49% and of flavonoids between 24.25–67.00%. The pomegranate juice and the juice of black grapes and aloe vera kept 58.12 and 50.36% of their initial anthocyanins content, while for the other samples less than 1.10% was established. As a result, a maximum of 30% remaining antioxidant activity was measured for some of the samples, but for most this was less than 10%. In conclusion, fruit juices are a rich source of biologically active substances, but a more detailed analysis of food transformation during digestion is needed. Full article

There is ample evidence that polyphenols are important natural substances with pronounced antioxidative properties. This study aimed to develop a fast and reliable method to determine total polyphenol content (TPC) in foodstuffs and human samples. The microtitration format offers the advantage of low sample volumes in the microlitre range, facilitating high-throughput screening with 40 samples simultaneously. We accordingly adjusted the so-called Folin–Ciocalteu method to a microtitre format (polyphenols microtitre—PPm) with 90% reduction of reagents. The assay was standardized with gallic acid in the range between 0.1 and 3 mM, using a 20 µL sample volume. The intra-assay coefficient of variation (CV) was less than 5%, and inter-assay CV was in the range of 10%. Wavelength was measured at 766 nm after two hours of incubation. This micromethod correlates significantly with both the classical Folin–Ciocalteu method and High-Performance Thin-Layer Chromatography (HPTLC) (r² = 0.9829). We further observed a significant correlation between PPm and total antioxidants (r² = 0.918). The highest polyphenol concentrations were obtained for red, blue, and black fruits, vegetables, and juices. Extracts of red grapes could be harvested almost sugar free and might serve as a basis for polyphenol supplementation. Beer, flour, and bread contained polyphenol concentrations sufficient to meet the minimal daily requirement. We conclude that PPm is a sensitive and reliable method that detects polyphenols even in samples diluted 10-fold. The literature strongly recommends further investigations on the effects of polyphenol uptake on human and animal health. Full article

The aim of this study was to evaluate the potential positive effect of black grape juice (BGJ) on lipid peroxidation considering Total Body Irradiation (TBI) in Wistar rats. As a potential feasible means of evaluation in situ, blood serum lactate dehydrogenase (LDH) levels were evaluated as a marker for heart damage from acute radiation syndrome (ARS). Twenty rats were divided into four groups, two of them being irradiated by gamma-rays from a Co-60 source. Animals were treated by gavage with 2 mL per day of BGJ or placebo for one week before and 4 days after 6 Gy whole body gamma-irradiation, when they were euthanasiated. LDH on serum and lipid peroxidation on heart tissue were evaluated. High concentration of metabolites from lipid peroxidation in heart, and high LDH level on serum were found only in gamma-irradiated group given placebo, mainly at the first 24 h after radiation. Phytochemical analysis of BGJ was performed by determining total phenolics, flavonoids, and tannins followed by a high-performance liquid chromatography (HPLC/DAD) analysis, which showed resveratrol as the major constituent. Results suggest that BGJ is a good protective candidate compound against heart damage from ARS and its effects suggest its use as a radiomodifier. Full article

n instrument for the automatic quantification of glycerol in grapes has been developed. We verify here that this analyte can be used as a benchmark of a serious disease affecting the grapevines, namely Botrytis cinerea. The core of the instrument is an amperometric biosensor consisting of a disposable screen printed electrode, generating the analytical signal thanks to a bi-enzymatic process involving glycerol dehydrogenase and diaphorase. The full automation of the analysis is realised by three micropumps and a microprocessor under control of a personal computer. The pumps allow the correct and constant dilution of the grape juice with a buffer solution also containing [Fe(CN)₆]³⁻ redox mediator and the injection of NAD⁺ cofactor when the baseline signal reaches a steady state; the instrument leads to automated reading of the analytical signal and the consequent data treatment. Although the analytical method is based on an amperometric technique that, owing to heavy matrix effects, usually requires an internal calibration, the analyses indicate that a unique external calibration is suitable for giving accurate responses for any grapes, both white and black ones. Full article