Evaluation of Egyptian honeys and their floral origins: phenolic compounds, antioxidant activities, and antimicrobial characteristics

In Vitro Prebiotic Effects and Antibacterial Activity of Five Leguminous Honeys

Honey is a natural remedy for various health conditions. It exhibits a prebiotic effect on the gut microbiome, including lactobacilli, essential for maintaining gut health and regulating the im-mune system. In addition, monofloral honey can show peculiar therapeutic properties. We in-vestigated some legumes honey's prebiotic properties and potential antimicrobial action against different pathogens. We assessed the prebiotic potentiality of honey by evaluating the antioxidant activity, the growth, and the in vitro adhesion of Lacticaseibacillus casei, Lactobacillus gasseri, Lacticaseibacillus paracasei subsp. paracasei, Lactiplantibacillus plantarum, and Lacticaseibacillus rhamnosus intact cells. We also tested the honey's capacity to inhibit or limit the biofilm produced by five pathogenic strains. Finally, we assessed the anti-biofilm activity of the growth medium of probiotics cultured with honey as an energy source. Most probiotics increased their growth or the in vitro adhesion ability to 84.13% and 48.67%, respectively. Overall, alfalfa honey best influenced the probiotic strains' growth and in vitro adhesion properties. Their radical-scavenging activity arrived at 83.7%. All types of honey increased the antioxidant activity of the probiotic cells, except for the less sensitive L. plantarum. Except for a few cases, we observed a bio-film-inhibitory action of all legumes' honey, with percentages up to 81.71%. Carob honey was the most effective in inhibiting the biofilm of Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus; it retained almost entirely the ability to act against the bio-film of E. coli, L. monocytogenes, and S. aureus also when added to the bacterial growth medium instead of glucose. On the other hand, alfalfa and astragalus honey exhibited greater efficacy in acting against the biofilm of Acinetobacter baumannii. Indigo honey, whose biofilm-inhibitory action was fragile per se, was very effective when we added it to the culture broth of L. casei, whose supernatant exhibited an anti-biofilm activity against all the pathogenic strains tested. Conclusions: the five kinds of honey in different ways can improve some prebiotic properties and have an inhibitory biofilm effect when consumed.

Citrus Honeys from Three Different Regions of Turkey: HPLC-DAD Profiling and in Vitro Enzyme Inhibition, Antioxidant, Anti-Inflammatory and Antimicrobial Properties with Chemometric Study

The objectives of the present study are to compare the phenolic profiles and biological activities of 15 citrus honey samples from three different locations in Turkey using a chemometric approach. The HPLC-DAD analysis was used to determine phenolic profiles. Nineteen phenolic compounds were identified. Gallic acid (107.14-717.04 μg/g) was recorded as the predominant compound. AF (Antalya-Finike) had the highest antioxidant activity in ABTS⋅+ (IC50 : 18.01±0.69 mg/mL), metal chelating (IC50 : 6.20±0.19 mg/mL) and CUPRAC (A0.50 : 12.05±0.68 mg/mL) assays, while it revealed the best anti-inflammatory activity against COX-2 (17.28±0.22 %) and COX-1 (43.28±0.91 %). AM (Antalya-Manavgat) was the most active in β-carotene-linoleic acid (IC50 : 10.05±0.19 mg/mL), anti-urease (38.90±0.69 %), anti-quorum sensing and antimicrobial activities. AKO1 (Adana-Kozan-1) in DPPH⋅ (IC50 : 34.25±0.81 mg/mL) assay, AKU1 (Antalya-Kumluca-1) in tyrosinase inhibition activity (37.73±0.38 %) assay, AKU2 (Antalya-Kumluca-2) in AChE (10.55±0.63 %) and BChE (9.18±0.45 %) inhibition activity assays showed the best activity. Chemometric tools were applied to the phenolic compositions and biological properties. PCA and HCA ensured that 15 citrus honey samples were grouped into 3 clusters. The results showed that myricetin, kaempferol, vanillin, protocatechuic acid, rosmarinic acid, rutin, vanillic acid, gallic acid, catechin and p-hydroxyphenyl acetic acid are phenolic compounds that can be used in the classification of citrus honeys.

The Bioactive Value of Tamarix gallica Honey from Different Geographical Origins

This study was conducted to assess the bioactive value of Tamarix gallica honey samples collected from three countries. In total, 150 Tamarix gallica honey samples from Saudi Arabia (50), Libya (50), and Egypt (50) were collected and compared, based on the results of the melissopalynological analysis, their physicochemical attributes, antioxidant and antimicrobial activities, and biochemical properties, together with their total phenolic and total flavonoid contents. Depending on the geographical origin, we observed different levels of growth suppression for six resistant bacterial strains. The pathogenic microorganisms tested in this study were Staphylococcus aureus, Streptococcus mutans, Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa. There was a strong correlation between the polyphenol and flavonoid contents, as well as significant (p < 0.05) radical scavenging activities. The melissopalynological analysis and physicochemical properties complied with the recommendation of the Gulf and Egyptian Technical Regulations on honey, as well as the Codex Alimentarius of the World Health Organization and the European Union Normative related to honey quality. It was concluded that Tamarix gallica honey from the three countries has the capacity to suppress pathogenic bacterial growth and has significant radical scavenging activities. Moreover, these findings suggest that Tamarix gallica honey may be considered as an interesting source of antimicrobial compounds and antioxidants for therapeutical and nutraceutical industries or for food manufacturers.

Honey's Antioxidant and Antimicrobial Properties: A Bibliometric Study

Research attention has been drawn to honey's nutritional status and beneficial properties for human health. This study aimed to provide a bibliometric analysis of honey's antioxidant and antimicrobial properties. The research advancements within this field from 2001 to 2022 were addressed using the Scopus database, R, and VOSviewer. Of the 383 results, articles (273) and reviews (81) were the most common document types, while the annual growth rate of published manuscripts reached 17.5%. The most relevant topics about honey's antimicrobial and antioxidant properties were related to the agricultural and biological sciences, biochemistry, and pharmacology. According to a keyword analysis, the most frequent terms in titles, abstracts, and keywords were honey, antimicrobial, antioxidant, bee, propolis, phenolic compounds, wound, antibacterial, anti-inflammatory, and polyphenols. A trend topic analysis showed that the research agenda mainly encompassed antioxidants, pathogens, and anti-infection and chemical agents. In a co-occurrence analysis, antioxidants, anti-infection agents, and chemistry were connected to honey research. The initial research focus of this domain was primarily on honey's anti-inflammatory and antineoplastic activity, wound healing, and antibacterial agents. The research agenda was enriched in the subsequent years by pathogens, propolis, oxidative stress, and flavonoids. It was possible to pinpoint past trends and ongoing developments and provide a valuable insight into the field of honey research.

In Vivo Anti-Alzheimer and Antioxidant Properties of Avocado (Persea americana Mill.) Honey from Southern Spain

There is growing evidence that Alzheimer's disease (AD) can be prevented by reducing risk factors involved in its pathophysiology. Food-derived bioactive molecules can help in the prevention and reduction of the progression of AD. Honey, a good source of antioxidants and bioactive molecules, has been tied to many health benefits, including those from neurological origin. Monofloral avocado honey (AH) has recently been characterized but its biomedical properties are still unknown. The aim of this study is to further its characterization, focusing on the phenolic profile. Moreover, its antioxidant capacity was assayed both in vitro and in vivo. Finally, a deep analysis on the pathophysiological features of AD such as oxidative stress, amyloid-β aggregation, and protein-tau-induced neurotoxicity were evaluated by using the experimental model C. elegans. AH exerted a high antioxidant capacity in vitro and in vivo. No toxicity was found in C. elegans at the dosages used. AH prevented ROS accumulation under AAPH-induced oxidative stress. Additionally, AH exerted a great anti-amyloidogenic capacity, which is relevant from the point of view of AD prevention. AH exacerbated the locomotive impairment in a C. elegans model of tauopathy, although the real contribution of AH remains unclear. The mechanisms under the observed effects might be attributed to an upregulation of daf-16 as well as to a strong ROS scavenging activity. These results increase the interest to study the biomedical applications of AH; however, more research is needed to deepen the mechanisms under the observed effects.

¹H-NMR Metabolic Profiling, Antioxidant Activity, and Docking Study of Common Medicinal Plant-Derived Honey

The purpose of this investigation was to determine ¹H-NMR profiling and antioxidant activity of the most common types of honey, namely, citrus honey (HC1) (Morcott tangerine L. and Jaffa orange L.), marjoram honey (HM1) (Origanum majorana L.), and clover honey (HT1) (Trifolium alexandrinum L.), compared to their secondary metabolites (HC2, HM2, HT2, respectively). By using a ¹H-NMR-based metabolomic technique, PCA, and PLS-DA multivariate analysis, we found that HC2, HM2, HC1, and HM1 were clustered together. However, HT1 and HT2 were quite far from these and each other. This indicated that HC1, HM1, HC2, and HM2 have similar chemical compositions, while HT1 and HT2 were unique in their chemical profiles. Antioxidation potentials were determined colorimetrically for scavenging activities against DPPH, ABTS, ORAC, 5-LOX, and metal chelating activity in all honey extract samples and their secondary metabolites. Our results revealed that HC2 and HM2 possessed more antioxidant activities than HT2 in vitro. HC2 demonstrated the highest antioxidant effect in all assays, followed by HM2 (DPPH assay: IC₅₀ 2.91, 10.7 μg/mL; ABTS assay: 431.2, 210.24 at 50 ug/mL Trolox equivalent; ORAC assay: 259.5, 234.8 at 50 ug/mL Trolox equivalent; 5-LOX screening assay/IC₅₀: 2.293, 6.136 ug/mL; and metal chelating activity at 50 ug/mL: 73.34526%, 63.75881% inhibition). We suggest that the presence of some secondary metabolites in HC and HM, such as hesperetin, linalool, and caffeic acid, increased the antioxidant activity in citrus and marjoram compared to clover honey.

Honey dressing: a missed way for orthopaedic wound care

Purpose

Orthopaedic-related wounds are critical situations calling for care to avoid deep infections and its consequences. The purpose of this study was to evaluate the efficacy of using honey for care of orthopaedic-related wounds with limited resources.

Patients and methods

This prospective study included 50 cases with an average age of 38.18 (range 17–63) years with 38 males and 12 females. The most frequent wound location was the leg (41 patients; 82%), then the foot (six patients; 12%), and the ankle in three patients (6%). The aetiologies were open fractures (34 cases; 68%), infected tibial non-unions (nine cases; 18%), and post-operative infections (seven cases; 14%). Exposed tendon was present in three cases. Bone exposure was present in two cases. Deep infection was present in 29 cases (58%). Besides treating the primary cause, a ribbon of gauze soaked with honey was applied to the wounds after thorough saline washing.

Results

Wound sizes were variable. All cases showed improvement in all parameters with complete wound healing and full coverage of bone and tendons. Recurrence of deep infection occurred in three cases and treated by debridement. One case needed sequestrectomy of a small exposed tibial cortical fragment. Exposed tendon cases showed superficial necrosis which was treated by simple debridement. Initial mild itching occurred in five patients with spontaneous resolution.

Conclusion

With treating the underlying aetiology and optimising the patient’s general condition, honey was an effective, simple, and affordable method of wound care in different orthopaedic conditions even with exposed bone or tendons.

A Review of the Phytochemistry and Bioactivity of Clover Honeys (Trifolium spp.)

This review covers a comprehensive overview of the phytoconstituents and bioactivities reported to date for clover honeys produced from various Trifolium spp. against the backdrop of a more general discussion of the chemistry and bioactivity of these important agricultural species. While research into the phytochemical composition of various honeys and their associated bioactivities is growing, this review demonstrates that the literature to date has seen only a limited number of studies on clover honeys. Surprisingly, there appear to be no comparative data on the concentration of flavonoids in general or isoflavonoids specifically in different clover honeys, although the latter have been identified as a main group of bioactive compounds in red clover plants. Based on the findings of this review, the presence of phytoestrogenic isoflavonoids (e.g., formononetin, biochanin A, genistein, daidzein, glycitein) in clover plants and, by extension, in clover honeys should be further investigated, specifically of clover species outside the three popular perennial clovers (red, white and alsike clovers) to exploit new opportunities of potential benefit to both the pharmaceutical and apiculture industries.

Arabinoxylan-Based Microcapsules Being Loaded with Bee Products as Bioactive Food Components Are Able to Modulate the Cell Migration and Inflammatory Response-In Vitro Study

The aim of the research was to use bioactive heteropolysaccharides isolated from rye bran to obtain innovative systems for the controlled release of bioactive compounds. The core of the obtained encapsulates was honey and royal jelly. It was shown for the first time that preparations effectively ameliorated inflammatory response in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, decreasing the secretion of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and nitric oxide (NO). The in vitro digestion process revealed that bee products’ encapsulates were stronger oxidative stress reducers and had sustained ability to reduction in inflammation state mediators. The lack of inhibitory effect on migration rate of human microvascular endothelial cells (HMEC-1) endothelial cells and mouse embryonic fibroblasts (NIH-3T3), both cell models involved in wound healing process, additionally identified these preparations as agents potentially used in the management of inflammatory response. In the process of a simulated digestion in vitro, the innovative microcapsules showed 85% higher biostability and two to ten times better bioavailability, compared to natural bee products.

Antifungal Activity of Honey Samples from Khyber Pakhtunkhwa (Pakistan) as affected by Botanical Origin

The present study evaluated the antifungal activity of honey samples collected from different locations at Khyber Pakhtunkhwa (KPK, Pakistan). Disc diffusion method was used to test the antifungal potential of twenty-one (branded, unbranded, and natural comb) honey samples from the different botanical origins at different concentrations (undiluted, 10%, 30%, and 50%, w/v) against Candida albicans and Rhodotorula species. Branded, unbranded, and natural comb honey samples generate different inhibition zones (4-13 mm, 5-15 mm, and 8-17 mm) against Rhodotorula species. Candida albicans showed resistance for all tested honey samples. Minimum inhibitory concentration (MIC) against Candida albicans and Rhodotorula species were 53.33%-88.12% and 1.76%-90.22% for branded, 61.3% – 93.8% and 9.90% – 95.5% for unbranded, and 67.1%-96.8% and 6.39%-98.8% for natural comb honey. In conclusion, natural comb honey from Khyber Pakhtunkhwa may have antifungal therapeutic potential and could be a useful source for generating functional food.

The Natural Cryoprotectant Honey for Fertility Cryopreservation

Honey is a mixture of 25 sugars with other bioactive substances (i.e., organic acids, enzymes, antioxidants, and vitamins) and has been known as a highly nutritious functional food. Traditionally, it has been widely used in medicinal applications to cure various diseases. The effectiveness of honey in different applications has been used for its antimicrobial activity, absorption of hydrops, cleansing, removing odor, assisting granulation, recovery of nutrition, and formation of tissue and epithelium, which proved that honey has dehydrating and preserving properties to make it ideal for the cryopreservation of cells and tissues. Cryopreservation is an advanced preservation technique for tissue, cells, organelles, or other biological specimen storage, performed by cooling the sample at a very low temperature. It is the most common approach to improved preserving fertility (sperm, embryos, and oocytes) in different species that may undergo various life-threatening illnesses and allows for the genetic screening of these cells to test the sample for diseases before use. However, with toxic cryoprotectant (CPA), cryopreservation of fertility has been challenging because of their particular structure and sensitivity to chilling. Honey’s unique composition, as well as its dehydrating and preserving properties, qualify it to be used as a natural cryoprotectant. The aim of this study is to emphasize the ability of honey as a natural cryoprotectant in cryopreservation. The articles for this review were searched from Google Scholar, PubMed, Science Direct, Web of Science, and Scopus, using the keywords, honey, cryopreservation, natural cryoprotectant/CPAs, extenders, and fertility. Honey, as a natural cryoprotectant in fertility cryopreservation, yielded satisfactory results, with respect to improved post-thaw quality and viability. It is now proved as a non-toxic and highly efficient natural cryoprotectant in fertility preservation because its increasing viscosity at low temperature can provide a protective barrier to cells by reducing ice formation. Furthermore, its antioxidant property plays a vital role in protecting the cells from thermal damage by reducing the reactive oxygen species (ROS). This review provides a road map for future studies to investigate the potential of honey in the cryopreservation of other cells and tissue and contribute to the scientific research, regarding this remarkable natural product.

Advances in Research on Food Bioactive Molecules and Health

Fresh and processed food products are rich in bioactive molecules, including polysaccharides, vitamins, carotenoids, peptides, antioxidants, phenolics, phytosterols, and novel lipids. Bioactive molecules in food could prevent several diseases (i.e., metabolic syndrome, cardiovascular diseases, cancer, etc.). Thus, consumer awareness is growing about the health-promoting impact of food bioactive molecules. Health claims are essential added-value features, wherein health-enhancing potential of bioactives depend on their chemical structure. On the other hand, the investigation of the structure-function relationship of food bioactive molecules is of importance. In this regard, Molecules is delighted to highlight the importance of food bioactive molecules and their effect on health. In this Special Issue of Molecules, researchers are invited to contribute original research and up-to-date reviews.

Current status of the gastrointestinal digestion effects on honey: A comprehensive review

In the past five years, more than 8000 scientific reports have been published on honey composition and its potential bioactivity as a source of pro-health components. However, the potential effectiveness of nutrients and other compounds in the human body is greatly influenced by the individual digestion conditions. Consequently, changes in the structure of honey components and their interactions with other constituents are expected and they may affect the bioaccessibility, the bioavailability, and further physiological functions of honey nutrients and bioactives. In this context, in addition to present key physiological characteristics for each step of the human digestion and their simulation aspects, this review also summarizes and discusses available data regarding the effect of the digestion (in vitro and in vivo) on honey compounds. Additionally, we consider the influence of the digestion on biological activities described for the compounds in the honey.

The Use of Ultrasound for Preventing Honey Crystallization

The aim of this study was to evaluate the effect of ultrasound treatment for preventing honey crystallization on the physicochemical and microbiological properties of unifloral honey and polyfloral honey. Honey samples without any treatment were used as a control group for comparison. The effect of applying ultrasound treatment was evaluated by studying over time the tendency of crystallization, the rheological properties of honey and chemical and microbiological properties. The parameters analyzed for the two groups of samples (treated and untreated with ultrasound), which did not vary or had small variations during the research were water content, acidity, water activity, glucose, fructose, sucrose, glucose/water ratio, glucose/fructose ratio. The crystallization process was installed in the control samples from the first month of the study, and much later in the treated samples. The color of the untreated samples varied considerably, and the color of the treated ones remained stable or slightly varied. For the control samples, the smallest variation in hydroxymethylfurfural (HMF) concentration was in raspberry honey (5%), and the most significant variation was in honeydew honey (30%). For the treated samples, the largest variation of this parameter was found in tillia honey (127%), and the smallest variation was in rapeseed honey (26%). The microbiological quality was higher for the treated samples. In the ultrasound-treated samples of acacia honey, honeydew honey and grassland honey, yeasts, molds or standard plate counts (SPCs) were undetectable. For control samples, SPC values were <10-50 cfu/g. Ultrasound-treated samples maintained their SPC parameter levels or were thus reduced (<10-20 cfu/g). Yeasts and molds were undetectable or had value between <10 and 10 cfu/g. The yeasts and the molds ranged in the control samples between <10 and 40 cfu/g.

Quality, composition and health-protective properties of citrus honey: A review

Citrus honey is one of the most important monofloral honeys produced and consumed worldwide. This honey has pleasant sensorial characteristics, which include light color and typical aroma and flavor. Besides that, several constituents such as minerals, phenolic and volatile compounds, amino acids, sugars, enzymes, vitamins, methylglyoxal and organic acids are found in citrus honey. Moreover, potential biological properties have been associated with citrus honey. All these factors make it highly desired by consumers, increasing its market value, which can stimulates the practice of fraud. Also, citrus honey is susceptible to contamination and to inadequate processing. All these factors can compromise the quality, safety and authenticity of citrus honey. In this sense, this review aims to update and to discuss, for the first time, the data available in the literature about the physicochemical and the sensorial characteristics, composition, health properties, contamination, authenticity and adulteration of citrus honey. With this background, we aim to provide data that can guide future researches related to this honey.

The combined antimicrobial activity of citrus honey and fosfomycin on multidrug resistant Pseudomonas aeruginosa isolates

Infections with Pseudomonas aeruginosa (P. aeruginosa) have become a real fear in hospital-acquired infections, especially in critically ill and immunocompromised patients. Thus, advance of novel anti-infectives is currently pursued. The aim of the present study was to evaluate the antibacterial effect of each of citrus honey and fosfomycin in comparison to the combined effect of both of them on multidrug resistant (MDR) P. aeruginosa. 50 MDR P. aeruginosa isolates were tested for the antibacterial effect of citrus honey. Screening for potential synergistic activity of fosfomycin and honey combinations by E test. Molecular detection of the virulent exoenzyme U (exoU) genotype by conventional PCR was done. The present study found that 50 % (v/v) concentration of citrus honey was sufficient to inhibit the growth of most isolates (33/50, 66%). Minimal inhibitory concentration (MIC) for fosfomycin tested by E test was found to be >128 µg/mL in 50(100%) of MDR P. aeruginosa isolates but after repeating E test with Mueller-Hinton agar (MHA) containing sublethal concentration of citrus honey (29/50,58%) isolates were sensitive. Also, there was a significant correlation between the presence of exoU gene and positive synergy of citrus honey-fosfomycin combination. This study showed that citrus honey has antibacterial effect and synergy with fosfomycin antibiotic against MDR P. aeruginosa isolates. Also, exoU positive genotype is associated with MDR phenotype. In conclusion, our results revealed that the citrus honey-fosfomycin combination showed highly statistically significant effect on MDR P. aeruginosa fosfomycin susceptibility pattern. exoU positive P. aeruginosa isolates were detected mostly in burn unit and ICUs. Also, there was a statistically significant correlation between the presence of exoU gene and positive result of honey-fosfomycin combination E test.