Antioxidant activities of some monofloral honey types produced across Turkey

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.

Extraction, physicochemical properties, bioactivities and application of natural sweeteners: A review

Natural sweeteners generally refer to a sweet chemical component directly extracted from nature or obtained through appropriate modifications, mainly secondary metabolites of plants. Compared to the first-generation sweeteners represented by sucrose and the second-generation sweeteners represented by sodium cyclamate, natural sweeteners usually have high sweetness, low-calorie content, good solubility, high stability, and rarely toxic side effects. Historically, researchers mainly focus on the function of natural sweeteners as substitutes for sugars in the food industry. This paper reviews the bioactivities of several typical natural sweeteners, including anti-cancer, anti-inflammatory, antioxidant, anti-bacterial, and anti-hyperglycemic activities. In addition, we have summarized the extraction, physicochemical properties, and application of natural sweeteners. The article aimed to comprehensively collate vital information about natural sweeteners and review the potentiality of tapping bioactive compounds from natural products. Hopefully, this review provides insights into the further development of natural sweeteners as therapeutic agents and functional foods.

Chemical Characterization and Biological Properties of Leguminous Honey

Honey can beneficially act against different human diseases, helping our body to improve its health. The aim of the present study was first to increase knowledge of some biochemical characteristics (amount and composition of polyphenols and volatile organic compounds, vitamin C content) of five Italian legume honeys (alfalfa, astragalus, carob, indigo, and sainfoin). Furthermore, we evaluated their potential health properties by studying their antioxidant and in vitro anti-inflammatory activities and in vitro inhibitory effects on three enzymes involved in neurodegenerative diseases (acetylcholinesterase, butyrylcholinesterase, and tyrosinase). Alfalfa honey showed the highest total polyphenol content (TPC) (408 μg g-1 of product). Indigo honey showed the lowest TPC (110 μg g-1 of product). The antioxidant activity was noteworthy, especially in the case of sainfoin honey (IC50 = 6.08 mg), which also exhibited excellent inhibitory action against butyrylcholinesterase (74%). Finally, the correlation between the biochemical and functional results allowed us to identify classes of molecules, or even single molecules, present in these five honeys, which are capable of influencing the properties indicated above.

Bioactive compounds of honey from different regions of Brazil: the effect of simulated gastrointestinal digestion on antioxidant and antimicrobial properties

Monofloral and multifloral honey produced in different regions may have different bioactive compounds and antioxidant capacities, resulting in changes in the antimicrobial activity of honey. However, many of these compounds degrade due to the extreme digestion conditions, which may inhibit the antimicrobial activity. Given this context, this study aimed to describe the bioactive compounds of honey produced in Brazil and verify if honey samples from different botanical and geographical origins differ in bioactive compounds, and if honey maintains its antimicrobial activity after digestion simulation. Multivariate analysis was used to identify characteristics that differentiated the honey samples according to the botanical and geographical origin criteria. The amount of the bioactive compounds varied significantly: the total phenolic compound content varied from 20.49 to 101.44 mg GAE per 100 g, flavonoids varied from 1.41 to 13.52 mg QE per 100 g, phenolic acids varied from 13.61 to 56.41 mg CAE per 100 g, and carotenoids varied from 0.66 to 4.27 mg β-carotene per g. Multifloral honey (H22) produced in the dry season of northeastern Brazil presented the highest bioactive compound concentration except for the carotenoid content. HPLC-MS analysis showed the presence of six hydroxybenzoic acids, four hydroxycinnamic acids, eight flavonols, three flavanones, two flavones and two isoflavonoids; Pterodon pubescens monofloral honey (H14) from midwestern Brazil stood out in terms of the carotenoid content. All analyzed honey samples exhibited antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria before digestive process simulation, and bacteria were inhibited during in vitro digestion; this activity decreased during the simulation of the oral phase, remained in the gastric phase, and disappeared in the intestinal phase.

Investigation of Oxidative Stress Level and Antioxidant Enzyme Activities in Operated and Nonoperated Patients with Spontaneous Intracerebral Hematoma

BACKGROUND

 Complex underlying mechanisms consisting of cytotoxic, excitotoxic, and inflammatory effects of intraparenchymal hemorrhage (ICH) are responsible for the highly detrimental effects on brain tissue. Oxidative stress also plays a significant role in brain damage after ICH; however, it is less important than other factors. In this study, we aimed to evaluate the oxidative stress parameters malondialdehyde (MDA) and antioxidant-reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CT) activities in operated and nonoperated patients with spontaneous ICH.

METHODS

 One hundred patients with spontaneous ICH and 100 healthy controls were included in this study. Within the indication, 50 of the 100 patients underwent decompressive surgery. MDA, GSH, SOD, and CT activities were measured in the serum obtained from the patients.

RESULTS

 SOD and CT levels were lower in the nonoperated group than in the operated and control groups. GSH was similar in the operated and nonoperated groups, but it was lower in the control group. However, MDA was higher in those who did not undergo surgery than in the other groups.

CONCLUSIONS

 In our study, MDA, an indicator of oxidative stress, was found to be lower, and CT and SOD activities were found to be higher in ICH patients who underwent decompression than in those who did not. This is the first study to present the correlations of MDA, SOD, CT, and GSH in operated and nonoperated patients with spontaneous ICH.

The anti-allergic potential of stingless bee honey from different botanical sources via modulation of mast cell degranulation

BACKGROUND

Allergy is an inflammatory disorder affecting around 20% of the global population. The adverse effects of current conventional treatments give rise to the increased popularity of using natural food products as complementary and alternative medicine against allergic diseases. Stingless bee honey, commonly known as Kelulut honey (KH) in Malaysia, has been used locally as a traditional remedy to relieve cough and asthma. This study evaluated the anti-allergic potential of KH collected from four different botanical sources on phorbol ester 12-myristate-3-acetate and calcium ionophore-activated human mast cells.

METHODS

The present study examined the inhibitory effects of all collected honey on the release of selected inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-4, IL-6, IL-8, histamine, and β-hexosaminidase in an activated HMC. Besides that, all honey's total phenolic content (TPC) was also examined, followed by using liquid chromatography with tandem mass spectrometry (LC-MS/MS) to identify the phytochemicals in the honey. Further examination of the identified phytochemicals on their potential interaction with selected signaling molecules in an activated mast cell was conducted using computational methods.

RESULTS

The results indicated that there were significant inhibitory effects on all selected inflammatory mediators' release by KH sourced from bamboo (BH) and rubber tree (RH) at 0.5% and 1%, but not KH sourced from mango (AH) and noni (EH). BH and RH were found to have higher TPC values and were rich in their phytochemical profiles based on the LC-MS/MS results. Computational studies were employed to determine the possible molecular target of KH through molecular docking using HADDOCK and PRODIGY web servers.

CONCLUSIONS

In short, the results indicated that KH possesses anti-allergic effects towards an activated HMC, possibly by targeting downstream MAPKs. However, their anti-allergic effects may vary according to their botanical sources. Nevertheless, the present study has provided insight into the potential application of stingless bee honey as a complementary and alternative medicine to treat various allergic diseases.

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.

Chemometric classification of chestnut honeys from different regions in Turkey based on their phenolic compositions and biological activities

The objective of this study was to investigate the phenolic composition and biological properties of chestnut honeys of 41 stations in Turkey's the Black Sea and Marmara regions. A total of sixteen phenolic compounds and organic acids were detected using HPLC-DAD and levulinic, gallic, protocatechuic, vanilic, trans-cinnamic acids and (4-hydroxyphenyl) ethanol were identified in all studied chestnut honeys. Antioxidant activities were measured by ABTS^•+, β-carotene-linoleic acid, CUPRAC, DPPH^•, and metal chelating assays. Antimicrobial activities were carried out against gram positive, gram negative bacteria and Candida species using well diffusion test. Anti-inflammatory activities were evaluated against COX-1 and COX-2 whereas enzyme inhibitory activities were assessed on AChE, BChE, urease, and tyrosinase. The chemometric classification of chestnut honeys were carried out using PCA and HCA and it was seen that some phenolic compounds contributed significantly to the classification of chestnut honeys from various geographical origin.

Effects of apitherapy against salivary gland disorder after radioactive iodine therapy for differentiated thyroid cancer

OBJECTIVE

Sialadenitis and salivary gland disorders are complications of radioactive iodine therapy (RAIT) that affect the quality of life of patients with differentiated thyroid cancer (DTC). The current study aimed to provide evidence on the protective effect of apitherapy on salivary gland function during RAIT in patients with DTC.

METHODS

In total, 120 patients with DTC who underwent total thyroidectomy were divided into the apitherapy group (group A, n = 60) and the control group (group B, n = 60). Group A received 2.5 g of acacia honey three times daily after each meal during admission for RAIT. Statistical analyses were performed using the Saxon test (which is used to evaluate saliva volume) and salivary gland scintigraphy (which is applied to assess maximum uptake ratio and washout ratio).

RESULTS

Compared with group B, group A presented with a more significantly positive change in the rate of amount of saliva before and after treatment (P < 0.01). Group B presented a significant decrease in the maximum uptake ratio of the bilateral parotid and submandibular glands on salivary gland scintigraphy (P < 0.05) and washout ratio of all salivary glands (P < 0.05). Group A did not present significant differences in the maximum uptake ratio and washout ratio.

CONCLUSIONS

Apitherapy can have protective effects against salivary gland disorder associated with RAIT in patients with DTC.

Evaluation of the antioxidant potency of Greek honey from the Taygetos and Pindos mountains using a combination of cellular and molecular methods

Honey is a complex mixture, containing ~180 compounds, produced by the Apis melifera bees, with promising antimicrobial and antioxidant properties. Nevertheless, the mechanisms through which honey exerts its effects remain under investigation. Plant antioxidants are found in honey and other bee products exhibiting a high bioactivity and molecular diversity. The aim of the present study was to estimate the antioxidant capacity of honey collected from areas in Greece by small‑scale producers by i) using in vitro cell free assays; and ii) by investigating the effects of honey varieties on the redox status of a liver cancer cell line (HepG2) using non‑cytotoxic concentrations. The findings of the present study will allow for the identification of Greek honeys with promising antioxidant capacity. For this purpose, six types of honey with various floral origins were examined in cell‑free assays followed by cell‑based techniques using flow cytometric analysis and redox biomarker level determination in order to evaluate the potential alterations in the intracellular redox system. The results indicated various mechanisms of action that are dependent on the honey type, concentration dependency and high antioxidant capacity. The extended findings from the literature confirm the ability of raw honey to influence the redox status of HepG2 cells. Nevertheless additional investigations are required to elucidate their mechanisms of action in cell line models.

Antioxidant Activity and Phenolic Compound Identification and Quantification in Western Australian Honeys

This study reports on the total phenolic content and antioxidant activity as well as the phenolic compounds that are present in Calothamnus spp. (Red Bell), Agonis flexuosa (Coastal Peppermint), Corymbia calophylla (Marri) and Eucalyptus marginata (Jarrah) honeys from Western Australia. The honey's total phenolic content (TPC) was determined using a modified Folin-Ciocalteu assay, while their total antioxidant activity was determined using FRAP and DPPH assays. Phenolic constituents were identified using a High Performance Thin-Layer Chromatography (HTPLC)-derived phenolic database, and the identified phenolic compounds were quantified using HPTLC. Finally, constituents that contribute to the honeys' antioxidant activity were identified using a DPPH-HPTLC bioautography assay. Based on the results, Calothamnus spp. honey (n = 8) was found to contain the highest (59.4 ± 7.91 mg GAE/100 g) TPC, followed by Eucalyptus marginata honey (50.58 ± 3.76 mg GAE/100 g), Agonis flexuosa honey (36.08 ± 4.2 mg GAE/100 g) and Corymbia calophylla honey (29.15 ± 5.46 mg GAE/100 g). In the FRAP assay, Calothamnus spp. honey also had the highest activity (9.24 ± 1.68 mmol Fe²⁺/kg), followed by Eucalyptus marginata honey (mmol Fe²⁺/kg), whereas Agonis flexuosa (5.45 ± 1.64 mmol Fe²⁺/kg) and Corymbia calophylla honeys (4.48 ± 0.82 mmol Fe²⁺/kg) had comparable FRAP activity. In the DPPH assay, when the mean values were compared, it was found that Calothamnus spp. honey again had the highest activity (3.88 ± 0.96 mmol TE/kg) while the mean DPPH antioxidant activity of Eucalyptus marginata, Agonis flexuosa, and Corymbia calophylla honeys were comparable. Kojic acid and epigallocatechin gallate were found in all honeys, whilst other constituents (e.g., m-coumaric acid, lumichrome, gallic acid, taxifolin, luteolin, epicatechin, hesperitin, eudesmic acid, syringic acid, protocatechuic acid, t-cinnamic acid, o-anisic acid) were only identified in some of the honeys. DPPH-HPTLC bioautography demonstrated that most of the identified compounds possess antioxidant activity, except for t-cinnamic acid, eudesmic acid, o-anisic acid, and lumichrome.

Solid-phase microextraction Arrow combined with comprehensive two-dimensional gas chromatography-mass spectrometry for the elucidation of the volatile composition of honey samples

In this work, a solid-phase microextraction (SPME) Arrow method combined with comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS) was developed for the elucidation of the volatile composition of honey samples. The sample preparation protocol was optimized to ensure high extraction efficiency of the volatile organic compounds (VOCs) which are directly associated with the organoleptic properties of honey and its acceptance by the consumers. Following its optimization, SPME Arrow was compared to conventional SPME in terms of sensitivity, precision, and number of extracted VOCs. The utilization of SPME Arrow fibers enabled the determination of 203, 147, and 149 compounds in honeydew honey, flower honey, and pine honey, respectively, while a significantly lower number of compounds (124, 94, and 111 for honeydew honey, flower honey, and pine honey, respectively) was determined using conventional SPME. At the same time, the utilization of SPME Arrow resulted in enhanced sensitivity and precision. All things considered, SPME Arrow and GC × GC-MS can be considered as highly suitable for the elucidation of the volatile composition of complex food samples resulting in high sensitivity and separation efficiency.

Synergic Effect of Honey with Other Natural Agents in Developing Efficient Wound Dressings

Honey has been used for therapeutic and nutritional purposes since ancient times. It was considered one of the essential medical assets in wound healing. According to research, honeybees have significant antibacterial, antioxidant, anti-inflammatory, antitumor, and wound-healing properties. Lately, scientific researchers have focused on apitherapy, using bee products to protect and strengthen the immune system. Since honey is the most important natural product rich in minerals, proteins, and vitamins, it has been intensively used in such therapies. Honey has gained significant consideration because of the beneficial role of its antioxidant compounds, such as enzymes, proteins, amino and organic acids, polyphenols, and carotenoids, but mainly due to flavonoids and phenolic acids. It has been proven that phenolic compounds are responsible for honey's biological activity and that its physicochemical properties, antioxidants, and antimicrobial potential are significant for human health. The review also presents some mechanisms of action and the medical applications of honey, such as wound healing dressings, skin grafts, honey-based nanofibers, and cochlear implants, as the most promising wound healing tools. This extensive review has been written to highlight honey's applications in medicine; its composition with the most important bioactive compounds also illustrates its synergistic effect with other natural products having remarkable therapeutic properties in wound healing.

A Comprehensive HPTLC-Based Analysis of the Impacts of Temperature on the Chemical Properties and Antioxidant Activity of Honey

Honeys are commonly subjected to a series of post-harvest processing steps, such as filtration and/or radiation treatment and heating to various temperatures, which might affect their physicochemical properties and bioactivity levels. Therefore, there is a need for robust quality control assessments after honey processing and storage to ensure that the exposure to higher temperatures, for example, does not compromise the honey's chemical composition and/or antioxidant activity. This paper describes a comprehensive short-term (48 h) and long-term (5 months) study of the effects of temperature (40 °C, 60 °C and 80 °C) on three commercial honeys (Manuka, Marri and Coastal Peppermint) and an artificial honey, using high-performance thin-layer chromatography (HPTLC) analysis. Samples were collected at baseline, at 6 h, 12 h, 24 h and 48 h, and then monthly for five months. Then, they were analysed for potential changes in their organic extract HPTLC fingerprints, in their HPTLC-DPPH total band activities, in their major sugar composition and in their hydroxymethylfurfural (HMF) content. It was found that, while all the assessed parameters changed over the monitoring period, changes were moderate at 40 °C but increased significantly with increasing temperature, especially the honeys' HPTLC-DPPH total band activity and HMF content.

Physicochemical Profile, Antioxidant and Antimicrobial Activities of Honeys Produced in Minas Gerais (Brazil)

Honeys can be classified as polyfloral or monofloral and have been extensively studied due to an increased interest in their consumption. There is concern with the correct identification of their flowering, the use of analyses that guarantee their physicochemical quality and the quantification of some compounds such as phenolics, to determine their antioxidant and antimicrobial action. This study aims at botanical identification, physicochemical analyses, and the determination of total polyphenols, chromatographic profile and antiradical and antimicrobial activity of honey from different regions of Minas Gerais. Seven different samples were analyzed for the presence of pollen, and color determination. The physicochemical analyses performed were total acidity, moisture, HMF, reducing sugar, and apparent sucrose. The compound profile was determined by UHPLC/MS, the determination of total phenolics and antiradical activity (DPPH method) were performed by spectrophotometry, and minimum inhibitory and bacterial concentrations were determined for cariogenic bacteria. All honey samples met the quality standards required by international legislation, twenty compounds were detected as the main ones, the polyfloral honey was the only honey that inhibited all of the bacteria tested. Sample M6 (Coffee) was the one with the highest amount of total polyphenols, while the lowest was M4 (Cipó-uva). Regarding the antioxidant activity, M5 (Velame) had the best result and M4 (Cipó-uva) was the one that least inhibited oxidation. Of the polyfloral honeys, there was not as high a concentration of phenolic compounds as in the others. Coffee, Aroeira, Velame and Polyfloral have the best anti-radical actions. Betônica, Aroeira, Cipó-uva and Pequi inhibited only some bacteria. The best bacterial inhibition results are from Polyfloral.

Singular and Combined Effects of Essential Oil and Honey of Eucalyptus Globulus on Anti-Inflammatory, Antioxidant, Dermatoprotective, and Antimicrobial Properties: In Vitro and In Vivo Findings

Eucalyptus globulus is a plant widely used by the world population, including Morocco, in the treatment of several pathologies. The aim of this work is to evaluate the antioxidant, anti-inflammatory, dermatoprotective, and antimicrobial effects of essential oil and honey from E. globulus, as well as their combination. Chemical composition was determined by GC-MS analysis. The antioxidant activity was evaluated by three tests, namely, DPPH, reducing power, and the β-carotene/linoleic acid assay. The anti-inflammatory activity was investigated in vitro (5-lipoxygenase inhibition) and in vivo (carrageenan-induced paw edema model), while the dermatoprotective activity was tested in vitro (tyrosinase inhibition). Moreover, the antibacterial activity was assessed using agar well diffusion and microdilution methods. The results showed that eucalyptol presents the main compound of the essential oil of E. globulus (90.14%). The mixture of essential oil with honey showed the best antioxidant effects for all the tests used (0.07 < IC50 < 0.19 mg/mL), while the essential oil was the most active against tyrosinase (IC50 = 38.21 ± 0.13 μg/mL) and 5-lipoxygenase (IC50 = 0.88 ± 0.01 μg/mL), which corroborated the in vivo test. Additionally, the essential oil showed the best bactericidal effects against all strains tested, with inhibition diameter values ranging from 12.8 to 21.6 mm. The findings of this work showed that the combination of the essential oil with honey showed important results in terms of biological activity, but the determination of the underlying mechanisms of action remains a major prospect to be determined.

Chemical Composition and the Anticancer, Antimicrobial, and Antioxidant Properties of Acacia Honey from the Hail Region: The in vitro and in silico Investigation

In consideration of the emergence of novel drug-resistant microbial strains and the increase in the incidences of various cancers throughout the world, honey could be utilized as a great alternative source of potent bioactive compounds. In this context, this study pioneers in reporting the phytochemical profiling and the antimicrobial, antioxidant, and anticancer properties of Acacia honey (AH) from the Hail region of Saudi Arabia, assessed using in vitro and molecular docking approaches. The phytochemical profiling based on high-resolution liquid chromatography-mass spectrometry (HR-LCMS) revealed eight compounds and three small peptide-like proteins as the constituents. The honey samples exhibited promising antioxidant activities (DPPH-IC₅₀ = 0.670 mg/mL; ABTS-IC₅₀ = 1.056 mg/mL; β-carotene-IC₅₀ > 5 mg/mL). In the well-diffusion assay, a high mean growth inhibition zone (mGIZ) was observed against Staphylococcus aureus (48.33 ± 1.53 mm), Escherichia coli ATCC 10536 (38.33 ± 1.53 mm), and Staphylococcus epidermidis ATCC 12228 (39.33 ± 1.15 mm). The microdilution assay revealed that low concentrations of AH could inhibit the growth of almost all the evaluated bacterial and fungal strains, with the minimal bactericidal concentration values (MBCs) ranging from 75 mg/mL to 300 mg/mL. On the contrary, high AH concentrations were required to kill the tested microorganisms, with the minimal bactericidal concentration values (MBCs) ranging from approximately 300 mg/mL to over 600 mg/mL and the minimal fungicidal concentration values (MFCs) of approximately 600 mg/mL. The AH exhibited effective anticancer activity in a dose-dependent manner against breast (MCF-7), colon (HCT-116), and lung (A549) cancer cell lines, with the corresponding IC₅₀ values of 5.053 μg/mL, 5.382 μg/mL, and 6.728 μg/mL, respectively. The in silico investigation revealed that the observed antimicrobial, antioxidant, and anticancer activities of the constituent compounds of AH are thermodynamically feasible, particularly those of the tripeptides (Asp-Trp-His and Trp-Arg-Ala) and aminocyclitol glycoside. The overall results highlighted the potential of AH as a source of bioactive compounds with significant antimicrobial, antioxidant, and anticancer activities, which could imply further pharmacological applications of AH.

STINGLESS BEE HONEY (Tetragonula laeviceps): CHEMICAL COMPOSITION AND THEIR POTENTIAL ROLES AS AN IMMUNOMODULATOR IN MALNOURISHED RATS

Honey is rich in bioactive compounds, phenolic acids, and flavonoids and is an antioxidant and an immunomodulator. The objectives of this study were to determine the honey chemical composition of Indonesian stingless bees and their potential roles as an immunomodulator in the malnourished rats. Tetragonula laeviceps honey was used to analyses of chemical composition was obtained from three different geographical origins were Depok Sleman, Bayan Lombok, and Nglipar Gunungkidul. Thirty-two rats were divided into four groups of 8 rats and placed in individual cages. The experimental designed was as follows: T1 = normal rats + without honey (0–7 weeks), T2 = normal rats + with honey of 1.8 g/kg BW/day (0–7 weeks), T3 = malnourished honey of 1.8 g/kg BW/day started from 2 weeks after the malnourished condition (2–7 weeks). The results showed that the chemical composition of Tetragonula laeviceps honey from three different geographical origins were vitamin C content (6.49–13.58 mg/100 g), total phenolic content (0.65–2.30% GAE/100 g), total flavonoid content (0.28–1.00 mg QE/g), and antioxidant activity DPPH (61.43–90.28%). The application of fresh honey from stingless bee that was offered to either normal or malnourished rats were increased lymphocytes proliferation and decreased the production of both proinflammatory markers, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) from tissue culture supernatant of lymphocytes (p < 0.01). Data from this study clearly indicates the potential role of honey from stingless bee as an immunomodulator in malnourished rats.

Chemical Composition, Antioxidant and Antimicrobial Activity of Some Types of Honey from Banat Region, Romania

Honey is a natural product with multiple health benefits. The paper presents the chemical characterization and the antioxidant and antimicrobial potential of ten types of honey (knotweed, linden, wild cherry, acacia, honeydew, oilseed rape, sunflower, phacelia, plain polyflora and hill polyflora) from the Banat region, Romania. We studied the water content, dry matter, impurities, acidity and pH of honey. We also determined the content of reducing sugar, minerals and flavonoids and the total phenolic content. All honey samples analysed showed good nutritional characteristics according to the standard codex for honey. From the analysis of the mineral content of the honey samples, we observed a variability in the macro and microminerals, influenced by the botanical origin, ranging between 0.25% (wild cherry honey) and 0.54% (honeydew). The toxic metals’ (Cd and Pb) levels met the standard for almost all samples analysed except for knotweed. The flavonoid content of the samples ranged from 9.29 mg QE/100 g for wild cherry honey to 263.86 mg QE/100 g for linden honey, and for polyphenols between 177.6 mgGAE/100 g for acacia honey and 1159.3 mgGAE/100 g for honeydew. The best antioxidant capacity was registered in the case of linden honey (79.89%) and honeydew (79.20%) and the weakest in acacia (41.88%) and wild cherries (50.4%). All studied honey samples showed antimicrobial activity, depending on the type of honey, concentration and strain analysed. The novelty of this study is given by the complex approach of the study of honey quality, both from the perspective of chemical attributes and the evaluation of the antimicrobial potential on specific strains in correlation with the botanical and geographical origin of the analyzed area.

Phytochemical Characterization and Bioactivity of Different Honey Samples Collected in the Pre-Saharan Region in Algeria

Despite the challenging conditions in the pre-Saharan areas of Algeria, such as weak plant cover and a harsh climate, beekeeping is being developed and spread. In the present work, honey samples collected from ten locations in the El Oued region were examined during the spring of 2021. A melissopalynological analysis was carried out, followed by a floristic investigation. The 10 honey samples were also investigated for their physicochemical properties and antioxidant and antibacterial activity against five strains: Escherichia coli, Staphylococcus aureus, Bacillus subtilus, Listeria innocua, and Micrococcus luteus. The floristic analysis found 65 species belonging to 33 botanical families, with a dominance of the Asteraceae family accounting for 18.461% of the total. The melissopalynological study revealed only one monofloral honey (Ziziphus lotus), whereas the nine others were multi-floral. The honey’s color changed from light to dark amber, and most tested honey was of high quality, fulfilling international criteria. The total phenol and flavonoid contents varied considerably amongst the various honey samples. Furthermore, LC-MS-MS phenolic profile analysis identified the presence of 20 chemicals, of which only three phenols were found in all honey types. Antioxidant capacity analyzed with FRAP test and antiradical activities against DPPH differed from one honey sample to another. Moreover, a significant correlation was recorded between the antioxidant activity, honey’s color, polyphenol, and flavonoid contents. The S. aureus strain was the most sensitive regarding honey antibacterial activity, while M. luteus and B. subtilis strains were only moderately sensitive.

Antioxidative, Antibacterial and Antiproliferative Properties of Honey Types from the Western Balkans

This paper presents the physicochemical characteristics and antioxidative, antibacterial and antiproliferative effects of nineteen samples of different honey types (acacia, linden, heather, sunflower, phacelia, basil, anise, sage, chestnut, hawthorn, lavender and meadow) collected from different locations in the Western Balkans (Republic of Serbia, Kosovo, Bosnia and Herzegovina, and Northern Macedonia). Physicochemical parameters (moisture, pH, electrical conductivity, free acidity, and hydroxymethylfurfural [HMF]) were analysed. Based on the obtained results, all tested honey samples were in agreement with EU regulation. The antioxidant potential of honey samples was assessed by determination of total phenolic content (TPC) and evaluation of scavenging activity towards diphenilpicrylhydrazyl radicals (DPPH·). The highest phenolic content was found in basil honey (101 ± 2.72 mg GAE/100 g), while the lowest was registered in rapeseed honey (11.5 ± 0.70 mg GAE/100 g). Heather, anise, phacelia, sage, chestnut and lavender honey samples were also rich in TP, containing 80−100 mg GAE/100 g. DPPH scavenging activity varied among the samples being the highest for lavender honey (IC50 = 88.2 ± 2.11 mg/mL) and the lowest for rapeseed honey (IC50 = 646 ± 8.72 mg/mL). Antibacterial activity was estimated in vitro using agar diffusion tests and measuring minimal inhibitory concentration (MIC). Among investigated bacterial strains following resistant potencies were determined: Escherichia coli > Escherichia coli ATCC 8739 > Enterococcus faecalis > Proteus mirabilis > Staphylococcus aureus > Staphylococcus epidermidis. The linden honey from Fruška Gora (MIC values of 3.12% and 6.25% against Staphylococcus aureus and Staphylococcus epidermidis, respectively) and phacelia honey (MIC values of 6.25% and 3.12% against S.Staphylococcus aureus and Staphylococcus epidermidis, respectively) showed the strongest antibacterial activity. Antiproliferative activity was evaluated using the colorimetric sulforhodamine B (SRB) assay. The highest antiproliferative activity was obtained from linden honey sample 1 (IC50MCF7 = 7.46 ± 1.18 mg/mL and IC50HeLa =12.4 ± 2.00 mg/mL) and meadow sample 2 (IC50MCF7 = 12.0 ± 0.57 mg/mL, IC50HeLa = 16.9 ± 1.54 mg/mL and IC50HT−29 = 23.7 ± 1.33 mg/mL) towards breast (MCF7), cervix (HeLa) and colon (HT-29) cancer cells. Active components other than sugars contributed to cell growth activity.

Potential Therapeutic Benefits of Honey in Neurological Disorders: The Role of Polyphenols

Honey is the principal premier product of beekeeping familiar to Homo for centuries. In every geological era and culture, evidence can be traced to the potential usefulness of honey in several ailments. With the advent of recent scientific approaches, honey has been proclaimed as a potent complementary and alternative medicine for the management and treatment of several maladies including various neurological disorders such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and multiple sclerosis, etc. In the literature archive, oxidative stress and the deprivation of antioxidants are believed to be the paramount cause of many of these neuropathies. Since different types of honey are abundant with certain antioxidants, primarily in the form of diverse polyphenols, honey is undoubtedly a strong pharmaceutic candidate against multiple neurological diseases. In this review, we have indexed and comprehended the involved mechanisms of various constituent polyphenols including different phenolic acids, flavonoids, and other phytochemicals that manifest multiple antioxidant effects in various neurological disorders. All these mechanistic interpretations of the nutritious components of honey explain and justify the potential recommendation of sweet nectar in ameliorating the burden of neurological disorders that have significantly increased across the world in the last few decades.

Bioactivity and Chemical Profile of Rubus idaeus L. Leaves Steam-Distillation Extract

The leaves of Rubus idaeus L., a by-product of the fruit food industry, are a known source of bioactive molecules, although the chemical composition has only been partially investigated. The main objective of this study was to examine the biological activities and the chemical composition of the extract of leaves of R. idaeus (RH), obtained by steam distillation (SD). The antioxidant capacity; the total phenolic content (TPC); the cytotoxic activity against tumor cell lines; and the antibacterial activity, in addition to the study of the chemical fingerprinting, carried out by Gas/Chromatography-Mass-Spectrometry (GC/MS) and Headspace (HS)-GC/MS, were established. The extract showed a strong antioxidant capacity and a modest antibacterial activity against two bacterial strains, as well as significant cytotoxic activity against tumor cell lines (Caco-2 and HL60) and being proliferative on healthy cells. Many of the GC-identified volatile molecules (1,8-cineol, β-linalool, geraniol, caryophyllene, τ-muurolol, citral, α-terpineol, 3- carene, α-terpinen-7-al, etc.) can explain most of the biological properties exhibited by the extract of R. idaeus L. The high biological activity of the RH and the high compatibility with the various matrices suggest good prospects for this extract, both in the food and cosmetic fields or in dietary supplements for improving human health.

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.

The Effect of the Use of Essential Oils in the Feed of Bee Families on Honey Chemical Composition and Antimicrobial Activity

Honey is a natural food with pharmacological properties. The present study was focused on the use of essential oils in the supplementary feeding of bee families for three weeks (spring). The purpose was to monitor the effect of essential oils (basil, thyme, juniper, cloves, mint, cinnamon, oregano, rosemary) on the chemical components of the resulting honey. The honey sampling period was carried out before the administration of essential oils in the supplementary feed of the bee families, after the administration of essential oils in the bee feed, respectively, after the first harvest (rapeseed). The honey samples were subjected to chemical analysis to determine humidity, impurities, ash, pH, acidity, total phenolic content (TPC) and flavonoid content (FC), reducing sugar content and antioxidant activity. In addition, the antimicrobial activity against nine strains was tested. We found out that all the essential oils used had a positive effect on the chemical composition of honey, especially the essential oil of oregano, mint, thyme, cinnamon. Experimental variants in which juniper and clove essential oil were introduced reduced the acidity of honey by 28.12% and 35.48%, respectively. Ash content varies between 0.23% and 0.46%, impurities content between 4.11% and 9.11%, while the values for pH were between 3.42 and 4.03. As for the TPC, they have increased considerably in all experimental variants to which essential oil has been added, compared to the batch fed only with sugar syrup, the highest value being recorded for the sample treated with cinnamon after the third harvest (163.94 mg/100 g). The FC values vary between 8.41–44.36 mg/100 g, depending of the treatment applied and the period of harvesting. Regarding the antimicrobial activity, the results highlighted that the essential oils present in the diet of bees produced honey with antimicrobial effect increased after two weeks after administration.

Quality Assessment of Goldenrod, Milkweed and Multifloral Honeys Based on Botanical Origin, Antioxidant Capacity and Mineral Content

The goal of the study was to evaluate the pollen spectrum, antioxidant capacity and mineral content of four Hungarian honey types, using multivariate statistical analysis. The light colored honeys were represented by milkweed honey and a multifloral (MF) honey with dominant pollen frequency of linden (MF-Tilia); the darker ones were goldenrod honey and a multifloral honey with Lamiaceae pollen majority (MF-Lamiaceae). The pollen spectrum of the samples was established with melissopalynological analysis. The absorbance of the honeys positively correlated with the antioxidant capacity determined with three of the used methods (TRC, TEAC, DPPH), but not with ORAC. The latter method correlated negatively also with other antioxidant methods and with most of the mineral values. MF-Tilia had high ORAC value, K and Na content. The MF-Lamiaceae had the highest K, Mg, P, S, Cu and Zn content, the last five elements showing strict correlation with the TRC method. The darker goldenrod honey had higher SET values and total mineral content, than the milkweed honey. The above character-sets facilitate identification of each honey type and serve as indicators of variety. The antioxidant levels and mineral content of honeys allowed their clear separation by principal component analysis (PCA).

Polyphenols Content and In Vitro α-Glycosidase Activity of Different Italian Monofloral Honeys, and Their Effect on Selected Pathogenic and Probiotic Bacteria

We evaluated the polyphenol content and the α-glucosidase activity exhibited by different monofloral honeys of Italian origin. Their capacity to act on different pathogenic (Acinetobacter baumannii, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus) as well as probiotic bacteria (Lacticaseibacillus casei, Lactobacillus acidophilus, Lactiplantibacillus plantarum, Lactobacillus gasseri, and Lacticaseibacillus rhamnosus) was also assessed. Total polyphenols varied between 110.46 μg/g of fresh product (rhododendron honey) and 552.29 μg/g of fresh product (strawberry tree honey). Such result did not correspond to a parallel inhibitory α-glycosidase activity that, in each case was never higher than 33 μg/mL. Honeys were differently capable to fight the biofilm formation of the pathogens (inhibition up to 93.27%); they inhibited the in vitro adhesive process (inhibition up to 84.27%), and acted on mature biofilm (with values up to 76.64%). Their effect on bacterial metabolism was different too. Honeys were ineffective to inhibit E. coli mature biofilm nor to act on its metabolism. The action of the honey on probiotic strains seemed almost always stimulate their growth. Thus, these monofloral honeys might exhibit effects on human health and act positively as prebiotics.

Monofloral Honeys as a Potential Source of Natural Antioxidants, Minerals and Medicine

Background: vegetative diversity is based on different climate and geographical origins. In terms of beekeeping, herbal diversity is strongly correlated to the production of a wide variety of honey. Therefore, based on the existing plant diversity in each country, multiple honey varieties are produced with different health characteristics. While beekeeping potential and consumption preferences are reflected in products’ variety, this leads to an increase in the region’s economy and extensive export. In the last years, monofloral honey has gained interest from consumers and especially in the medicinal field due to the presence of phytochemicals which are directly linked to health benefits, wound healing, antioxidant, anticancer and anti-inflammatory activities. Scope and approach: this review aims to highlight the physicochemical properties, mineral profiles and antioxidant activities of selected monofloral honeys based on their botanical and geographical origin. Moreover, this review focuses on the intercorrelation between monofloral honey’s antioxidant compounds and in vitro and in vivo activities, focusing on the apoptosis and cell proliferation inhibition in various cell lines, with a final usage of honey as a potential therapeutic product in the fight towards reducing tumor growth. Key findings and conclusions: multiple studies have demonstrated that monofloral honeys have different physicochemical structures and bioactive compounds. Useful chemical markers to distinguish between monofloral honeys were evidenced, such as: 2-methoxybenzoic acid and trimethoxybenzoic acid are distinctive to Manuka honey while 4-methoxyphenylacetic acid is characteristic to Kanuka honey. Furthermore, resveratrol, epigallocatechin and pinostrobin are markers distinct to Sage honey, whereas carvacrol and thymol are found in Ziziphus honey. Due to their polyphenolic profile, monofloral honeys have significant antioxidant activity, as well as antidiabetic, antimicrobial and anticancer activities. It was demonstrated that Pine honey decreased the MDA and TBARS levels in liver, kidney, heart and brain tissues, whereas Malicia honey reduced the low-density lipoprotein level. Consumption of Clover, Acacia and Gelam honeys reduced the weight and adiposity, as well as trygliceride levels. Furthermore, the antiproliferative effect of chrysin, a natural flavone in Acacia honey, was demonstrated in human (A375) and murine (B16-F1) melanoma cell lines, whereas caffeic acid, a phenolic compound found in Kelulut honey, proves to be significant candidate in the chemoprevention of colon cancer. Based on these features, the use of hiney in the medicinal field (apitherapy), and the widespread usage of natural product consumption, is gaining interest by each year.

Organochlorine pesticides in honeybee, pollen and honey in Bursa, Turkey

g-In this study, the presence of OCP residues in the honeybee, pollen and honey samples in urban and semi-urban areas were investigated. A total of 10 OCP concentrations (∑₁₀OCP) in honeybee samples were 39.14 ± 11.06 ng g^-1 for the urban area and 39.93 ± 7.09 ng g^-1 for the semi-urban area, respectively. Similarly, ∑₁₀OCP concentrations in pollen and honey samples were estimated to be 21.72 ± 4.43 ng g^-1 and 41.83 ± 1.61 ng g^-1 for the urban area, 19.77 ± 2.86 ng g^-1 and 39.23 ± 3.90 ng g^-1 for the semi-urban area, respectively. Also, it was concluded that the existence of OCP residues in both sampling areas was due to the recent use of pesticides. Finally, the cancer risk caused by the consumption of pollen and honey samples was evaluated, and it was found that there was no cancer risk in both sampling areas.

Quality Evaluation of Light- and Dark-Colored Hungarian Honeys, Focusing on Botanical Origin, Antioxidant Capacity and Mineral Content

Melissopalynology, antioxidant capacity and mineral and toxic element contents were analyzed in eight types of Hungarian honeys. Based on color, two groups were distinguished: light honeys comprised acacia, amorpha, phacelia and linden honeys; while dark honeys included sunflower, chestnut, fennel and sage honeys, with 100 to 300 and 700 to 1500 mAU, respectively. The unifloral origin of each sample was supported using pollen analysis. The absorbance of honey correlated positively with antioxidant capacity determined by three different methods (TRC, DPPH, ORAC), and also with mineral content. The exception was the light amber linden honey with significantly higher K content and antiradical activity than other light honeys. The Mn, Zn and Fe contents were the highest in chestnut, sunflower and fennel honeys, respectively. The black meadow sage honey performed best regarding the content of other elements and antioxidant activity. The concentrations of several toxic elements were below the detection limit in the samples, indicating their good quality. The principal component analysis (PCA) revealed correlations between different antioxidant assays and minerals, and furthermore, confirmed the botanical authentication of the honeys based on the studied parameters. To our best knowledge, the present study is the first to provide a complex analysis of quality parameters of eight unifloral Hungarian honeys.

The Relationship between the Browning Index, Total Phenolics, Color, and Antioxidant Activity of Polish-Originated Honey Samples

Honey is a source of sugars, amino acids/proteins, and polyphenols, which are the main substrates and reactants in the Maillard reaction. Several bioactive molecules are formed and sequestered to the brown polymeric melanoidins, resulting in a gain and loss of antioxidant function in honey. Therefore, the relationships between the browning index and total phenolic contents, color, and antioxidant activity of Polish-originated honeys, namely acacia, buckwheat, heather, linden, multiflorous, and rapeseed, obtained from three local beekeepers, were addressed in this study. The Total Phenolic Content data showed the following order: buckwheat > heather > acacia > multiflorous > linden > rapeseed. The buckwheat honey also had the highest ability to scavenge free radicals in the range of 207.1–289.3 and 40.9–52.3 µmol Trolox g⁻¹, provided by Antioxidant Compounds Water-soluble and Ferric Reducing Antioxidant Power assays, respectively. Furthermore, a higher degree of browning was observed in dark-colored honey, such as buckwheat (3.1) and heather (1.35 mAU), than in light ones. Moreover, L* and b* parameters had a greater value in the honey of multiflorous, linden, and rapeseed, and a* was higher in buckwheat and heather. The variables of browning and TPC, ACW, and FRAP were positively correlated with each other. It can be concluded that the browning index strongly contributed to parameters of honey appearance, bioactive compound content, and antioxidant activity.

Physicochemical properties, total phenolic content, and antioxidant activity of chestnut, rhododendron, acacia and multifloral honey

The aim of this study is to investigate the physicochemical properties, antioxidant activities, and total phenolic contents of the plateau (multifloral), chestnut, rhododendron, and acacia honey collected from Ordu province in Turkey. The rhododendron honey had the highest acidity (p < 0.05) while the chestnut honey showed the highest conductivity (1.13 ± 0.25 mS/cm) among all (p < 0.05). The highest diastase activities and the lowest HMF contents were determined in the multifloral and chestnut honey. Considering the DPPH and FRAP assays, the multifloral honey showed the highest antioxidant activity. Accordingly, the highest total phenolic content was determined in the multifloral honey followed by rhododendron, chestnut, and acacia honey. A moderate correlation was determined between the total phenolic content and antioxidant activities (r = 0.575 for FRAP and r = 0.697 for DPPH). Consequently, the plateau honey could be recommended for nutritional and health purposes due to its relatively higher antioxidant activity and total phenolic content together with relatively lower HMF content and higher diastase activity. Considering that Ordu is the largest honey producer city in Turkey, the second top honey producer country, this work could shed light for future studies and be taken as a reference providing insights on the characteristics of different types of honey for both local and worldwide producers.

Transcriptomic Analysis of Pseudomonas aeruginosa Response to Pine Honey via RNA Sequencing Indicates Multiple Mechanisms of Antibacterial Activity

Pine honey is a unique type of honeydew honey produced exclusively in Eastern Mediterranean countries like Greece and Turkey. Although the antioxidant and anti-inflammatory properties of pine honey are well documented, few studies have investigated so far its antibacterial activity. This study investigates the antibacterial effects of pine honey against P. aeruginosa PA14 at the molecular level using a global transcriptome approach via RNA-sequencing. Pine honey treatment was applied at sub-inhibitory concentration and short exposure time (0.5× of minimum inhibitory concentration –MIC- for 45 min). Pine honey induced the differential expression (>two-fold change and p ≤ 0.05) of 463 genes, with 274 of them being down-regulated and 189 being up-regulated. Gene ontology (GO) analysis revealed that pine honey affected a wide range of biological processes (BP). The most affected down-regulated BP GO terms were oxidation-reduction process, transmembrane transport, proteolysis, signal transduction, biosynthetic process, phenazine biosynthetic process, bacterial chemotaxis, and antibiotic biosynthetic process. The up-regulated BP terms, affected by pine honey treatment, were those related to the regulation of DNA-templated transcription, siderophore transport, and phosphorylation. Pathway analysis revealed that pine honey treatment significantly affected two-component regulatory systems, ABC transporter systems, quorum sensing, bacterial chemotaxis, biofilm formation and SOS response. These data collectively indicate that multiple mechanisms of action are implicated in antibacterial activity exerted by pine honey against P. aeruginosa.

Bioactive compounds in Apis mellifera monofloral honeys

Honey is a natural product with a sweet flavor. Honey is made by the honeybee (Apis mellifera L.) from the nectar of flowers or other plant secretions that are collected near the hive. These products are mixed with bee saliva and stored. Several studies have demonstrated that honey exhibits antioxidant, antimicrobial, nematicidal, antifungal, anticancer, and anti-inflammatory activities. These properties are influenced by the plants from which the secretions are harvested, from the naturally occurring compounds present in the nectar. Studies of the properties and applications of honey have distinguished honey from other natural products due to the presence of certain compounds and due its bioactive properties. The focus of this review is to discuss the identified and isolated compounds from monofloral honey produced by A. mellifera, with specific emphasis on antioxidant and antimicrobial properties of honey and its therapeutic health benefits.

Relationships between the Content of Phenolic Compounds and the Antioxidant Activity of Polish Honey Varieties as a Tool for Botanical Discrimination

The study compared the content of eight phenolic acids and four flavonoids and the antioxidant activity of six Polish varietal honeys. An attempt was also made to determine the correlations between the antioxidant parameters of the honeys and their polyphenol profile using principal component analysis. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (ABTS) and reduction capacity (FRAP) were determined spectrophotometrically, and the phenolic compounds were determined using high-performance liquid chromatography (HPLC). The buckwheat honeys showed the strongest antioxidant activity, most likely because they had the highest concentrations of total phenols, total flavonoids, p-hydroxybenzoic acid, caffeic acid, p-coumaric acid, vanillic acid and chrysin. The principal component analysis (PCA) of the data showed significant relationships between the botanic origin of the honey, the total content of phenolic compounds and flavonoids and the antioxidant activity of the six Polish varietal honeys. The strongest, significant correlations were shown for parameters of antioxidant activity and TPC, TFC, p-hydroxybenzoic acid, caffeic acid and p-coumaric acid. Analysis of four principal components (explaining 86.9% of the total variance), as a classification tool, confirmed the distinctiveness of the Polish honeys in terms of their antioxidant activity and content of phenolic compounds.

A comprehensive study of parameters correlated with honey health benefits

One hundred honey samples of different floral origin (acacia, sunflower, meadow, and forest) collected from nine European countries (Serbia, Albania, Croatia, Montenegro, Romania, Bulgaria, Bosnia and Herzegovina, North Macedonia and Hungary) were analysed for various physicochemical, sensory, antioxidant and antibacterial parameters. The relative antioxidant capacity index and relative antibacterial index were calculated, integrated and expressed as a new property - Power of Honey, intended to be used to predict the health potential of a honey based on its antioxidant and antibacterial activities. Free acidity and colour coordinates L* and a* were chosen for building an artificial neural network model for the prediction of honey health potential. These were chosen based on the obtained correlations between the investigated parameters and in light of the simplicity of the analysis. This model successfully predicted the Power of Honey with a gained coefficient of determination of 0.856. Forest honey samples exhibited the highest Power of Honey. This novel approach should make it possible for honey producers to predict the honey health potential of a particular honey based on a quick and simple analysis.

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.

In vitro anti-inflammatory properties of honey flavonoids: A review

Honey is a natural ready-to-eat product rich in flavonoids, which is known by the wound healing properties due to both antibacterial and antioxidant activity. Flavonoids mitigate inflammatory processes, and thus it could currently support studies of anti-inflammatory potential of honeys. In this review, in vitro anti-inflammatory properties of flavonoids found in honey were prioritized. Mechanistic information of specific isolated flavonoids as modulators of inflammatory processes are summarized aiming to stimulate studies regarding the action of honey in inflammatory events. Lastly, a structure-activity relationship (SAR) of flavonoids was also included. Flavonoids found in honey have demonstrated antioxidant properties and ability to inhibit pro-inflammatory enzymes such as COX, LOX, iNOS, and pro-inflammatory mediators, including nitric oxide, cytokines and chemokines. Transcriptional factors such as NF-κB are also modulated by flavonoids, controlling the expression of several inflammatory mediators. SAR studies demonstrate the effect of flavonoids in the prevention of inflammatory cascades. Despite the promising reports of in vitro anti-inflammatory activity, well-designed clinical trials need yet to be performed to confirm the benefits of honeys from different botanical sources in diseases that include episodes of inflammation.

Role of milk and honey in the tolerance of lactobacilli to oxidative stress

In the development of functional probiotic food, the carrier matrices should be carefully selected and optimized to ensure the highest levels of probiotic survival in the symbiotic food along storage. Because milk and honey food matrices are rich in antioxidant substances, the aim of the research was to evaluate their effect in protecting lactobacilli from reactive oxygen species (ROS) generated by the addition of hydrogen peroxide. Viability assays were performed with and without the addition of H₂O₂, in three different matrices: 0.9% peptone saline, 5% honey, or 12% reconstituted skim milk. The milk matrix provided protection for the Lacticaseibacillus paracasei DTA83 and Lacticaseibacillus rhamnosus DTA76. However, this protective effect was not observed in the survival of Lactobacillus acidophilus La 5. Honey solution did not maintain the viability of probiotic microorganisms exposed to hydrogen peroxide and, on the contrary, caused a significant reduction in the population of L. rhamnosus DTA76 (p < 0.001). Lower membrane lipid peroxidation due to H₂O₂ exposure was observed in L. acidophilus La 5 and L. rhamnosus DTA76, but this marker showed no relation with viability. It was concluded: (i) lactobacilli from the Lacticaseibacillus genus were the ones that benefited most from the lactic environment; (ii) the absence of the protective effect of honey was possibly due to the presence of Fe²⁺ which reacts with H₂O₂ to produce hydroxyl radicals; and (iii) cell viability did not correlate with membrane lipid peroxidation, and it is not a good marker to evaluate this type of damage in cells of different microorganisms.

Antioxidant HPTLC-DPPH Fingerprinting of Honeys and Tracking of Antioxidant Constituents Upon Thermal Exposure

The use of High-Performance Thin-Layer Chromatography (HPTLC) coupled with the use of DPPH* (2,2-diphenyl-1-picrylhydrazyl) as a derivatisation reagent is a novel approach to the analysis of antioxidant activity of honeys. The method facilitates the visualisation of individual constituents that contribute to the overall antioxidant activity of the honey, even if they are not yet chemically identified, and allows for the quantification of their antioxidant activity as gallic acid equivalents. The method supports a more in-depth study of the antioxidant activity of honey as it allows for a comparative analysis of the antioxidant fingerprints of honeys of different floral origin and is able to capture differences in their individual bioactive constituents. Further, it supports the tracking of changes in antioxidant activity of individual honey constituents over time upon exposure to different temperature conditions, which demonstrates the potential value of the method for in-process quality control.

Antioxidant Activity in Bee Products: A Review

Bee products have been used since ancient times both for their nutritional value and for a broad spectrum of therapeutic purposes. They are deemed to be a potential source of natural antioxidants that can counteract the effects of oxidative stress underlying the pathogenesis of many diseases. In view of the growing interest in using bioactive substances from natural sources to promote health and reduce the risk of developing certain illnesses, this review aims to update the current state of knowledge on the antioxidant capacity of bee products such as honey, pollen, propolis, beeswax, royal jelly and bee venom, and on the analytical methods used. The complex, variable composition of these products and the multitude of analytical methods used to study their antioxidant activities are responsible for the wide range of results reported by a plethora of available studies. This suggests the need to establish standardized methods to more efficiently evaluate the intrinsic antioxidant characteristics of these products and make the data obtained more comparable.

Antioxidant activity and enzyme inhibitory potential of Euphorbia resinifera and E. officinarum honeys from Morocco and plant aqueous extracts

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.