Antiviral and Antibacterial Effect of Honey Enriched with Rubus spp. as a Functional Food with Enhanced Antioxidant Properties

Preparation of Functional Food with Enhanced Antioxidant Properties by Adding Aronia melanocarpa Polyphenol Honey

To enhance the functionality of honey, particularly its antioxidant capacity, the incorporation of Aronia melanocarpa polyphenols (AMPs) is an effective approach. The preparation technology and antioxidant activity of AMP added to honey were studied. AMP was extracted with ethanol and its components were analyzed and then mixed evenly with honey in different addition amounts (0.1~0.5% w/w). The product was characterized based on the active ingredients (total phenols, total flavonoids, and anthocyanin content) and antioxidant activity (DPPH, ABTS, and reducing power) during storage to obtain the optimal storage time. The optimal polyphenol addition amount was determined by combining honey enzyme activity (amylase, glucose oxidase, and sucrase), sensory evaluation, and acute cell toxicity experiments. The optimal preparation process is an addition of 0.4% AMP and a storage time of 14 days or more. The active ingredients of the product are positively correlated with the AMP addition, and the antioxidant activity is significantly improved (from two to eight times). AMP exhibits a notable inhibitory effect on enzyme activity, with concentrations ranging from 0.1% to 0.4%, resulting in enzyme activity levels in honey remaining at 75% or higher. Honey samples containing 0.1% to 0.5% AMP exhibit minimal to no acute toxicity to cells. AMP can improve the nutritional value of honey, imparting unique color and flavor while enhancing its antioxidant activity. As such, it holds significant potential as a novel functional food.

A Critical Exploration of the Total Flavonoid Content Assay for Honey

This study critically investigates the aluminium chloride-based colorimetric determination of the total flavonoid content (TFC) of honey. Following a comprehensive review of the recent literature reporting the use of the assay in the determination of TFC in honey, 10 honeys of different botanical origins were investigated using the colorimetric method alongside an artificial honey that was used as a control. Using spiking experiments, this study demonstrates that the flavonoid concentrations commonly found in honey are too low for a direct measurement and thus some of the TFC data reported in the literature might more likely be a reflection of the honey's inherent colour rather than a product of the coordination complex formed specifically between flavonoids and Al3+ ions. This paper highlights the importance of correct blanking and suggests alternative approaches to the traditional TFC assay for honey to ensure analysis results that are truly reflective of honey's TFC.

Comparative Metabolome and Transcriptome Analysis Revealed the Accumulative Mechanism of Rubusoside in Chinese Sweet Tea

Terpenoids are important secondary metabolites in Rubus. Rubusoside is a relatively specific diterpenoid bioactive component in the leaves of Chinese Sweet Tea (Rubus suavissimus). However, the terpenoid anabolic pathway of Rubus and the molecular mechanism underlying the specific accumulation of rubusoside in R. suavissimus remain unclear. Here, metabolomics and transcriptomics analyses were performed on differences in terpenoid metabolism levels between R. suavissimus (sweet leaves) and Rubus chingii (bitter leaves). Steviol glycosides and goshonosides primarily accumulated in R. suavissimus and R. chingii, respectively. Three pairs of highly homologous glycosyltransferase genes (UGT85A57, UGT75L20, and UGT75T4) associated with rubusoside biosynthesis in the two Rubus species were identified. The three pairs of UGT proteins in both species could glycosylate steviol. Thus, the transcriptional regulation of UGTs in R. suavissimus appears to play a pivotal role in rubusoside accumulation. Our findings provide insights into the differences in terpenoid metabolism between R. suavissimus and R. chingii and reveal the molecular mechanism of rubusoside accumulation in R. suavissimus.

Honey Enriched with Additives Alleviates Behavioral, Oxidative Stress, and Brain Alterations Induced by Heavy Metals and Imidacloprid in Zebrafish

Environmental concerns have consistently been a focal point for the scientific community. Pollution is a critical ecological issue that poses significant threats to human health and agricultural production. Contamination with heavy metals and pesticides is a considerable concern, a threat to the environment, and warrants special attention. In this study, we investigated the significant issues arising from sub-chronic exposure to imidacloprid (IMI), mercury (Hg), and cadmium (Cd), either alone or in combination, using zebrafish (Danio rerio) as an animal model. Additionally, we assessed the potential protective effects of polyfloral honey enriched with natural ingredients, also called honey formulation (HF), against the combined sub-chronic toxic effects of the three contaminants. The effects of IMI (0.5 mg·L-1), Hg (15 μg·L-1), and Cd (5 μg·L-1), both individually and in combination with HF (500 mg·L-1), on zebrafish were evaluated by quantifying acetylcholinesterase (AChE) activity, lipid peroxidation (MDA), various antioxidant enzyme activities like superoxide dismutase and glutathione peroxidase (SOD and GPx), 2D locomotor activity, social behavior, histological and immunohistochemical factors, and changes in body element concentrations. Our findings revealed that all concentrations of pollutants may disrupt social behavior, diminish swimming performances (measured by total distance traveled, inactivity, and swimming speed), and elevate oxidative stress (OS) biomarkers of SOD, GPx, and MDA in zebrafish over the 21-day administration period. Fish exposed to IMI and Hg + Cd + IMI displayed severe lesions and increased GFAP (Glial fibrillary acidic protein) and S100B (S100 calcium-binding protein B) protein expression in the optic tectum and cerebellum, conclusively indicating astrocyte activation and neurotoxic effects. Furthermore, PCNA (Proliferating cell nuclear antigen) staining revealed reduced cell proliferation in the IMI-exposed group, contrasting with intensified proliferation in the Hg + Cd group. The nervous system exhibited significant damage across all studied concentrations, confirming the observed behavioral changes. Moreover, HF supplementation significantly mitigated the toxicity induced by contaminants and reduced OS. Therefore, the exposure to chemical mixtures offers a more complete picture of adverse impacts on aquatic ecosystems and the supplementation with bioactive compounds can help to reduce the toxicity induced by exposure to environmental pollutants.

Honeydew Honey as a Reservoir of Bacteria with Antibacterial and Probiotic Properties

The purpose of this study was to isolate, identify, and evaluate the antibacterial and probiotic potential of bacteria from honeydew honey collected in Poland. Isolates (189 colonies from 10 honey samples) were evaluated for their antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Yersinia enterocolitica, and then identified by MALDI-TOF-MS. The isolates with the greatest antimicrobial properties were screened for their probiotic potential. The total number of bacteria isolated from honey did not exceed the value of 2.5 × 102 CFU/mL. The Bacillus pumilus/altitudinis, B. licheniformis, and Bacillus cereus groups were the dominant identified bacteria. Almost 16% of the isolates expressed antibacterial potential against three pathogenic bacteria, over 20% against two, while almost 34% of the isolates did not inhibit any. The survival rate of the isolates under gastrointestinal tract conditions was higher after 4 h of exposure to bile salts (>60% survival rate for 66.66% of the isolates), while at pH 2.0, it was lower (>50% survival rate for 44% of the isolates). The most resistant isolate B. pumilus/altitudinis survived at a rate of 77% at low pH and 108% with bile salts. These results confirmed that honeydew honey is a promising reservoir of bacteria that produces metabolites with antimicrobial and probiotic potential.

Physicochemical Characterization of Moroccan Honey Varieties from the Fez-Meknes Region and Their Antioxidant and Antibacterial Properties

Honey, with its varied and extensive characteristics, is a complex and diverse biological substance that has been used since ancient times. The aim of this study is to thoroughly characterize the physicochemical, phytochemical, and biological properties of four floral honey varieties from the Fez-Meknes region in Morocco, with the goal of promoting the valorization of Moroccan honey in skincare and cosmetic products. The analyses of their physicochemical characteristics encompass various parameters such as pH, acidity, density, water content, Brix index, conductivity, ash content, hydroxymethylfurfural (HMF) content, and color. The levels of polyphenols range from 22.1 ± 0.4 to 69.3 ± 0.17 mg GAE/100 g of honey, measured using the Folin-Ciocalteu method for polyphenol quantification. Additionally, the estimation of flavonoid quantities in 100 g of honey, conducted using the aluminum trichloride method, reveals values ranging from 3.6 ± 0.2 to 7.2 ± 0.6 mg QE. Furthermore, it is noteworthy that honey exhibits high levels of glucose and relatively low concentrations of proteins. The quantitative evaluation of antioxidant effects, carried out through the 2,2-diphenyl-1-picrylhydrazyl free-radical-scavenging method and the ferric-reducing antioxidant power (FRAP) method, highlights the strong antioxidant capacity of multifloral honey, characterized by low inhibitory concentration values (IC50 = 30.43 mg/mL and EC50 = 16.06 mg/mL). Moreover, all honey varieties demonstrate antibacterial and antifungal properties, with multifloral honey standing out for its particularly pronounced antimicrobial activity. The correlation analyses between phytochemical composition and antioxidant and antibacterial activities reveal an inverse relationship between polyphenols and IC50 (DPPH) and EC50 (FRAP) concentrations of honey. The correlation coefficients are established at R2 = -0.97 and R2 = -0.99, respectively. Additionally, a significant negative correlation is observed between polyphenols, flavonoids, and antifungal power (R2 = -0.95 and R2 = -0.96). In parallel, a marked positive correlation is highlighted between antifungal efficacy, DPPH antioxidant activity (R2 = 0.95), and FRAP (R2 = 0.92). These results underscore the crucial importance of phytochemical components in the beneficial properties of honey, meeting international quality standards. Consequently, honey could serve as a natural alternative to synthetic additives.

Uncovering Potentially Therapeutic Phytochemicals, In silico Analysis, and Biological Assessment of South-Chinese Red Dragon Fruit (Hylocereus polyrhizus)

Red dragon fruit is gaining popularity globally due to its nutritional value and bioactive components. The study aimed to assess the phytochemical, nutritional composition, antioxidant, antibacterial, and cytotoxic properties of extracts from the South Chinese red dragon fruit peel, flesh, and seeds. Extract fractions with increasing polarity (ethyl acetate Collapse

Key Words

• In silico
• Antibacterial
• Antioxidant
• Cytotoxicity
• LC-MS/MS
• Red dragon-fruit

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MESH Headings

• Humans
• Anti-Bacterial Agents/pharmacology
• Anti-Bacterial Agents/analysis
• Antioxidants/pharmacology
• Antioxidants/analysis
• Cactaceae/chemistry
• Computer Simulation
• Fruit/chemistry
• HaCaT Cells
• Microbial Sensitivity Tests
• Nutritive Value
• Phytochemicals/pharmacology
• Phytochemicals/analysis
• Plant Extracts/pharmacology
• Plant Extracts/chemistry
• Quercetin/analysis
• Quercetin/pharmacology
• Seeds/chemistry
• Tandem Mass Spectrometry

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Affiliation(s)

Ali Asghar School of Food and Drug, Shenzhen Polytechnic University, Shenzhen, 518055, China
Lin Huichun Shenzhen Institute of Quality and Safety Inspection Research, Shenzhen, 518055, China
Qiao Fang School of Food and Drug, Shenzhen Polytechnic University, Shenzhen, 518055, China
Naveed Ahmad Khan Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul, 34010, Turkey
Muhammad Shahid Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, 43600, Malaysia
Wang Rui Shenzhen Institute of Quality and Safety Inspection Research, Shenzhen, 518055, China.
Wang Jun School of Food and Drug, Shenzhen Polytechnic University, Shenzhen, 518055, China.

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Biological Properties of Recently Described Wild Bramble Rubus oklejewiczii against the Species from Similar Niches

The aim of this study was to compare the biological properties, such as antiviral, antibacterial, and antioxidant, of recently described pentaploid species Rubus oklejewiczii with tetraploid taxa growing in similar habitats including R. plicatus, R. gracilis, and R. wimmerianus. The antiviral potential was analyzed against bacteriophages with different genetic material: phi6 (a surrogate for the SARS-CoV-2 virus), T7, phiX174, and MS2. Antibacterial properties of fruit and leaf extracts were determined against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella enterica. The total phenolic content, as well as anthocyanins, ascorbic acid, pH, and antioxidant properties (FRAP and DPPH) were determined. R. oklejewiczii leaf extract was characterized by the weakest antibacterial and antiviral properties, which was closely correlated with the lowest content of polyphenolic compounds and antioxidant properties. The strongest biological properties were observed for R. wimmerianus leaves. Fruit extracts were characterized by lower phenolic content and antioxidant activities than leaves, with the lowest values observed for R. oklejewiczii extract. The antibacterial properties of fruit extracts were strongest for R. gracilis. The strongest antiviral potential was observed for R. oklejewiczii and R. wimmerianus fruit extracts against the bacteriophage phi6, which correlated with the lowest pH and the highest ascorbic acid content. The positive effect of the higher ploidy of R. oklejewiczii for most of the analyzed biological properties was not observed except for the antiviral potential of fruit extract. Due to its large and tasty fruits, this species seems to be very promising for cultivation and attractive for consumers, even though most of its biological properties were not any better compared to other examined tetraploid species.

The Antibacterial Properties of Polish Honey against Streptococcus mutans-A Causative Agent of Dental Caries

Streptococcus mutans is considered the main pathogen responsible for dental caries, one of the major infectious diseases, affecting more than 4 billion people worldwide. Honey is a natural product with well-known antibacterial potential against several human pathogens. The aim of the study was to evaluate the antibacterial efficacy of Polish honey against S. mutans and analyze the role of some bioactive substances on its antibacterial action. The antibacterial potential of different honey varieties (goldenrod, buckwheat, honeydew, and lime) was analyzed using a microdilution assay. Manuka and artificial honey were used as controls. The content of GOX, hydrogen peroxide, total polyphenols, and antioxidant potential was assayed in honey. The influence of catalase and proteinase K on antibacterial activity as well as antibiofilm action was also determined. The strongest antibacterial activity was observed for buckwheat, honeydew, and manuka honey, which were also characterized by the highest antioxidant activity and polyphenols content. Catalase treatment decreases the antibacterial activity of honey, while proteinase K treatment influences the antibacterial potential of honey slightly less. Obtained results suggest that honey can be a good natural product against S. mutans, and hydrogen peroxide was identified as a crucial contributor to its antimicrobial action.

Rubi idaei fructus as a Source of Bioactive Chemical Compounds with an Important Role in Human Health and Comparison of the Antioxidant Potential of Fruits and Juice of Three Repeat-Fruiting Rubus idaeus L. Cultivars

Rubi idaei fructus is a source of nutritionally important bioactive chemical compounds, mainly antioxidants, which strengthen the immune system and can be used in the prophylaxis and adjuvant therapies of many oxidative stress-induced diseases. There are no literature reports presenting a comprehensive comparative analysis of the antioxidant activity and nutritionally relevant metabolites contained in the fruits of repeat-fruiting raspberry cultivars, which are commonly grown in Europe. The aim of this study was to carry out a comparative analysis of the antioxidant potential (Folin-Ciocalteu, DPPH, FRAP), the content of selected primary and secondary metabolites, and the qualitative and quantitative composition of amino acids and fatty acids in the fruits of R. idaeus cv. 'Pokusa', 'Polana', and 'Polka'. The fruits of the analyzed cultivars have a low caloric value (171-219 kcal/100 g); low content of available carbohydrates (6-6.6%) and total carbohydrates (3.4-4.8%); and high levels of dietary fiber (4.7-5.8%), vitamin C (22.8-27 mg/100 g), anthocyanins (25.1-29.6 mg/100 g), and flavonoids (0.5-2.6 mg/100 g). The fruits were found to contain valuable unsaturated fatty acids (35-60%), especially MUFAs with dominant oleic, elaidic, palmitic, and erucic acids and PUFAs (α-linolenic, eicosapentaenoic, and linoleic acids). MUFAs from the ω-9 group accounted for 12-18%, whereas the content of PUFAs from the ω-3 and ω-6 groups was in the range of 15-23 and 6-21%, respectively. Exogenous amino acids, accounting for 56-62%, were dominated by leucine, phenylalanine, and lysine. The following order of the total polyphenolic content was established in the fresh fruit juice from the analyzed cultivars: 'Pokusa' < 'Polana' < 'Polka'. The different antioxidant capacity assays used in the study confirmed the high antioxidant potential of the fruits and fresh juice from the three R. idaeus cultivars. This indicates that raspberry fruits can serve as a source of nutrients and can be used as a valuable supplement in a healthy human diet and a raw material in the pharmaceutical and cosmetic industries.

Untapped potential of non-conventional rubus species: bioactivity, nutrition, and livelihood opportunities

Rubus species holds promise as a valuable source of polyphenols and bioactive compounds, offering significant potential as functional food ingredients with both nutraceutical and pharmaceutical benefits. However, many edible species within this genus remain under-explored and their importance is largely unrecognized. This review aims to provide an overview of the nutritional and bioactive components of both explored and under-explored Rubus species, highlighting their potential health advantages, value addition, and recent advancements. The economic exploitation of Rubus is currently limited to a few cultivated species, while numerous non-conventional and wild edible species are overlooked. Recognizing the economic and nutritional significance of exploited Rubus species, it is imperative to explore the untapped potential of these underutilized plants. By doing so, these species can be preserved from endangerment and contribute to nutritional and livelihood security for communities having access to them. This review emphasizes the importance of understanding the exceptional characteristics of Rubus species as "superfoods" and encourages the promotion and cultivation of these unexplored species. By expanding the cultivation and utilization of under-explored Rubus species, we can unlock their full potential and support sustainable nutritional and economic benefits.

Exploring Consumers' Preferences and Attitudes to Honey: Generation Approach in Slovakia

Honey is popular among consumers for its composition and healing properties. The aim of the paper is to study the differences in honey preferences across various age generations in Slovakia. The study is based on primary data obtained by conducting an online questionnaire survey on a sample of 1850 Slovak consumers of honey in 2022. Multiple correspondence analyses and non-parametric tests were applied to study the differences in preferences across selected age cohorts (Generation Z, Generation Y, Generation X and Silver Generation). The results show that Silver Generation tends to consume honey due to its nutritional values and prefers to consume monofloral honey of a dark colour, while Generation Z does not use honey in cosmetics or consume it due to its nutritional values and are inclined to prefer polyfloral honey. The utilisation of honey in cosmetics was associated mostly with Generation X. Younger consumers (Generation Z and Generation Y) have a very low awareness of creamed honey and honey with additions in comparison to Silver Generation or Generation X. In addition, the results reveal that propolis, royal jelly and bee pollen were the most attractive additions for honey across all age cohorts in Slovakia, while spirulina and chilli were the least attractive additions.

The Antioxidant, Antibacterial and Anti-Biofilm Properties of Rapeseed Creamed Honey Enriched with Selected Plant Superfoods

The aim of the study is to evaluate the effect of the addition of selected fruits and herbs belonging to the "superfoods" category for the bioactivity of a rapeseed honey matrix. Flavored creamed honeys with nine types of various additives (2 and 4% of content) were prepared and analyzed for the content of total phenols, flavonoids, antioxidant (FRAP, DPPH and ABTS) and antibacterial activity against four strains of bacteria. Additionally, the impact of three months of storage on the antioxidant properties of the products obtained was examined. The significant dose-dependent increase in the content of bioactive ingredients and antioxidant capacity in spiced honeys, as compared to control honey, was observed. The highest enrichment was obtained for the addition of powdered sea buckthorn leaves and black raspberry fruits. Honey with the addition of sea buckthorn leaves inhibited the growth of P. aeruginosa, S. aureus and K. pneumonia, whereas honeys with black raspberry and blackcurrant fruits showed activity only on the latter two strains. Furthermore, what is more interesting, honey supplemented with sea buckthorn leaf and black raspberry fruits inhibited S. aureus biofilm formation at the sub-minimum inhibitory concentrations (sub-MICs), showing a dose-dependent anti-biofilm effect.

Honey and Its Biomimetic Deep Eutectic Solvent Modulate the Antioxidant Activity of Polyphenols

Honey is a highly valued natural product with antioxidant, antimicrobial and anti-inflammatory properties. However, its antioxidant activity (AOA) is not as high as that of other honeybee products, such as propolis. Several polyphenol-honey formulations have been proposed up to now, most of them using maceration of biomass in honey or mixtures with liquid extracts, which either limit polyphenols bioavailability or destroy the characteristics of honey. To improve the health benefits of honey by increasing AOA and keeping its structural and sensory properties, we propose its enrichment in a polyphenol extract of raspberry after solvent evaporation. A honey-biomimetic natural deep eutectic solvent (NaDES) was prepared and compared with honey. The main polyphenols found in the raspberry extract were tested in combination with honey and NaDES, respectively. The AOA was determined by DPPH, ABTS, CUPRAC, and FRAP methods. The AOA behaviour of honey-polyphenol mixtures varied from synergism to antagonism, being influenced by the AOA method, polyphenol type, and/or mixture concentration. The honey-biomimetic NaDES resulted in similar AOA behaviour as with honey mixed with polyphenols. Honey seems to have additional properties that increase synergism or reduce antagonism in some cases. Honey and its biomimetic NaDES modulate AOA of polyphenols extract.