Volatile profile of bee bread

Bee bread is one of the least studied bee products. In this study, ten bee bread samples were characterized using palynology and HS-SPME-GC-MS (headspace solid-phase microextraction gas chromatography-mass spectrometry). In total, over one hundred different volatile components were identified, belonging to different chemical groups. Only ten common components were detected in all the samples. These volatiles were ethanol, ethylene chloride, ethyl acetate, acetic acid, α-pinene, furfural, nonane, nonanal, n-hexane and isovaleric acid. Several other components were commonly shared among various bee bread samples. Over sixty detected compounds have not been previously reported in bee bread. The analysis required a mild extraction temperature of 40 °C, as higher temperatures resulted in the Maillard reaction, leading to the production of furfural. The profile of volatile compounds of the tested bee pollen samples was complex and varied. Some relationships have been shown between botanical origin and volatile organic compound profile.

Changes in phenolic profile and anti-inflammatory activity of Baccharis beebread during gastrointestinal digestion/intestinal permeability in vitro

Knowledge about the fate of beebread bioactive compounds throughout the human gastrointestinal tract are scarce. The present study aimed at assessing the effects of gastrointestinal digestion followed by intestinal permeability in vitro on phenolic profile and anti-inflammatory activity of Baccharis beebread. Palynological analysis confirmed the beebread is predominantly composed by pollen grains from Baccharis species, which are endemic in south and southeast Brazil. Flavonols and phenylamides were found in beebread hydroalcoholic extract by HPLC-ESI-QTOF-MS analysis. Moreover, simulated digestion lead to compounds' breakage, releasing both aglycones from glycosylated flavonols and p-coumaric acid, but not caffeic acid from phenylamides. Only spermidines crossed the Caco-2 cell monolayer, possibly due to spermine oxidation. Free p-coumaric acid was released after digestion, and epithelial transport. Concomitantly, NF-κΒ activation and TNF-α level was decreased by beebread even after Caco-2 transport, which indicates spermidines conjugated with p-coumaric acid may be bioavailable compounds with anti-inflammatory activity.

Yeast communities related to honeybees: occurrence and distribution in flowers, gut mycobiota, and bee products

Honeybee (Apis mellifera) is an important agricultural pollinator and a model for sociality. In this study, a deep knowledge on yeast community characterizing the honeybees' environmental was carried out. For this, a total of 93 samples were collected: flowers as food sources, bee gut mycobiota, and bee products (bee pollen, bee bread, propolis), and processed using culture-dependent techniques and a molecular approach for identification. The occurrence of yeast populations was quantitatively similar among flowers, bee gut mycobiota, and bee products. Overall, 27 genera and 51 species were identified. Basidiomycetes genera were predominant in the flowers while the yeast genera detected in all environments were Aureobasidium, Filobasidium, Meyerozyma, and Metschnikowia. Fermenting species belonging to the genera Debaryomyces, Saccharomyces, Starmerella, Pichia, and Lachancea occurred mainly in the gut, while most of the identified species of bee products were not found in the gut mycobiota. Five yeast species, Meyerozyma guilliermondii, Debaryomyces hansenii, Hanseniaspora uvarum, Hanseniaspora guilliermondii, and Starmerella roseus, were present in both summer and winter, thus indicating them as stable components of bee mycobiota. These findings can help understand the yeast community as a component of the bee gut microbiota and its relationship with related environments, since mycobiota characterization was still less unexplored. In addition, the gut microbiota, affecting the nutrition, endocrine signaling, immune function, and pathogen resistance of honeybees, represents a useful tool for its health evaluation and could be a possible source of functional yeasts. KEY POINTS: • The stable yeast populations are represented by M. guilliermondii, D. hansenii, H. uvarum, H. guilliermondii, and S. roseus. • A. pullulans was the most abondance yeast detective in the flowers and honeybee guts. • Aureobasidium, Meyerozyma, Pichia, and Hanseniaspora are the main genera resident in gut tract.

Comparison of APIStrip passive sampling with conventional sample techniques for the control of acaricide residues in honey bee hives

Western honey bees are very sensitive bioindicators for studying environmental conditions, hence frequently included in many investigations. However, it is very common in both research studies and health surveillance programs to sample different components of the colony, including adult bees, brood and their food reserves. These practices are undoubtedly aggressive for the colony as a whole, and may affect its normal functioning and even compromise its viability. APIStrip-based passive sampling allows long-term monitoring of residues without affecting the colony in any way. In this study, we compared the effectiveness in the control of acaricide residues by using passive and conventional sampling, where the residue levels of the acaricides coumaphos, tau-fluvalinate and amitraz were evaluated. Conventional and APIStrip-based sampling differ in methods for evaluating bee exposure to residues. APIStrip is less invasive than conventional sampling, offers more efficient measurement of environmental contaminants, and can be stored at room temperature, saving costs and minimizing operator error.

Probiotic potential of Bacillus Isolates from Polish Bee Pollen and Bee Bread

The main goal of this study was the evaluation of the probiotic potential of 10 Bacillus spp. strains isolated from 5 bee bread and 3 bee pollen samples. The antagonistic interaction with Staphylococcus aureus and Escherichia coli was a primary criterion for the preliminary selection of the isolates. Three out of ten strains-PY2.3 (isolated from pollen), BP20.15 and BB10.1 (both isolated from bee bread)-were found to be possible probiotic strains. All these strains are safe for humans (exhibiting [Formula: see text]-hemolytic activity) and meet all essential requirements for probiotics in terms of viability in the presence of bile salts and acid conditions, hydrophobicity, auto-aggregation, and co-aggregation with the cells of important human pathogenic bacteria. They also assimilate more than 30% of cholesterol after 24 h of incubation. These three isolates are resistant to penicillin but sensitive (or exhibit moderate resistance) to the other nine antibiotics tested herein. On the basis of whole-genome sequencing, BP20.15 and BB10.1 were classified as B. subtilis and PY2.3 as B. velezensis. Moreover, genomic analyses revealed that all these isolates are potential producers of different antimicrobial compounds, including bacteriocins and secondary metabolites. The outcomes of this study have proven that some of the Bacillus strains isolated from bee pollen or bee bread are potential probiotics.

Bee pollen and bee bread nutritional potential: Chemical composition and macronutrient digestibility under in vitro gastrointestinal system

Bee pollen (BP) and bee bread (BB) have been often investigated as potential functional foods. Both bee products are generally characterized by their high nutritional content, with BB being referred as more digestible than BP, however, there is a lack of scientific studies proving this claim. Here, we present a comparative evaluation of the macronutrient digestibility of BP and BB after applying a simulated in vitro gastrointestinal digestive system, together with the evaluation of its nutritional value and chemical composition. The digestibility scores for protein content were calculated on average as 69% and 76% for BP and BB, respectively, whereas digestibility scores for soluble sugars varied depending on bee product and sugar type. The results demonstrated that the nutritional values of both bee products changed depending on their botanical origin but BB is more accessible in the intestinal lumen, especially regarding protein.

Quantitation of pesticides in bee bread collected from honey bee colonies in an agricultural environment in Switzerland

Pesticide contamination of bee products is a widespread phenomenon. Due to its composition, bee bread is affected by both lipophilic and hydrophilic substances. As proof of concept of a monitoring campaign and to better understand the extent of contamination, we developed an analytical method based on a modified QuEChERS extraction, with subsequent separation by liquid chromatography and detection by mass spectrometry. This allowed for the quantitation of 51 agricultural- or beekeeping-associated pesticides in bee bread. The workflow was applied to 60 samples taken biweekly throughout spring to autumn 2022 from five colonies at a Swiss apiary in an agricultural area. In total, 30 pesticides were identified (> LOD), among which 26 pesticides were quantitated. The total number of pesticides detected per colony ranged from 11 to 19. The most prevalent substances (> LOQ) were two neonicotinoid insecticides, acetamiprid and thiacloprid (max. 16 μg/kg and 37 μg/kg, respectively); seven fungicides, azoxystrobin (max. 72 μg/kg), boscalid (max. 50 μg/kg), cyprodinil (max. 1965 μg/kg), difenoconazole (max. 73 μg/kg), mandipropamid (max. 33 μg/kg), pyraclostrobin (max. 8 μg/kg) and trifloxystrobin (max. 38 μg/kg); and two herbicides, prosulfocarb (max. 38 μg/kg) and terbuthylazine (max. 26 μg/kg). The study revealed strong variability in pesticide occurrence and concentrations among colonies sampled at the same site and date. The applied biweekly sampling of bee bread from March to August was shown to be reliable in capturing peak contaminations and revealing the onset of certain pesticides in bee bread. The study provides an adequate practical approach for pesticide monitoring campaigns.

Pollen and bee bread expressed highest anti-inflammatory activities among bee products in chronic inflammation: an experimental study with cotton pellet granuloma in rats

Little is known about the effectiveness of bee products on chronic inflammation. In this experimental study, it was aimed to investigate and compare the anti-inflammatory activities of honey, propolis, royal jelly, pollen and bee bread, for the first time in the literature. In the study, 48 Sprague Dawley female albino rats weighing 200 ± 20 g were used and bee products were administered by oral gavage method. Healthy, control, honey, propolis, pollen, royal jelly and bee bread groups were randomized. Chronic inflammation was created by cotton pellet method. For the treatments, 1 g/kg of honey, 300 mg/kg/day of pollen, 100 mg/kg/day of propolis, 500 mg/kg/day of bee bread and 100 mg/kg/day of royal jelly were given for seven days. One week later, cotton pellets were removed, and the pro-inflammatory and anti-inflammatory cytokine levels of the blood samples were measured and compared statistically. It was found that honey, propolis, pollen, bee bread and royal jelly had statistically significant anti-inflammatory activities and significantly reduced pro-inflammatory cytokine levels (p < 0.001). Among the anti-inflammatory cytokines, pollen, bee bread and propolis were found to increase the levels of IL-4, IL-10 and IL-1RA the most. Among the pro-inflammatory cytokines, pollen, bee bread and propolis were the ones that decreased IL-6 and TNF-α levels the most; Pollen, bee bread and honey were found to decrease IL-1β the most (p < 0.001). It was found that all bee products have significant anti-inflammatory activities. The highest anti-inflammatory activity was found with pollen administration, followed by bee bread and propolis.

Investigation of Botanical Origin, Phenolic Compounds, Carotenoids, and Antioxidant Properties of Monofloral and Multifloral Bee Bread

Bee bread is a unique natural product made by bees and good for human health. It has many bioactive molecules that can treat or prevent diseases. In this study, melissopalynological methods were used to examine five bee bread samples. Major plant sources found in bee bread were Lotus spp., Trifolium spp., and Xeranthemum spp., which are from the Fabaceae and Asteraceae families. Then, the amount of phenolic compounds and major carotenoids in bee bread (BB) samples were quantified. Gallic acid, caffeic acid, quercetin, and kaempferol were found in all BB samples, with β-carotene being the most abundant carotenoid in all but BB1. In addition, the total phenolic/flavonoid content and antioxidant activities of all BB samples were determined. Total flavonoid, total phenolic, DPPH⋅, and ABTS⋅⁺ values were varied between 5.6-10.00 mg GAE/g DW, 1.2-4.3 mg QE/g DW, 1.2-5.5 mg TEAC/g DW, and 2.6-15.4 mg TEAC/g DW, respectively.

Transfer of xenobiotics from contaminated beeswax into different bee matrices under field conditions and the related exposure probability

Beeswax is known to have a high capacity to accumulate different contaminants due to its fat-soluble properties. Many surveys in Europe and the USA have shown high levels of contamination in beeswax especially with acaricides used for varroa treatment. In this study, we investigated the transfer pathways of various active substances from beeswax into different matrices under field conditions. Honey, bee bread, larvae, and pupae samples were collected 6-8 weeks after building the experimental colonies on different charges of wax foundations. Identification and quantification of the target substances were performed with an established and validated multi-residue method using LC-MS/MS and GC-MS systems. Nine out of 19 active substances in wax could be detected in the analyzed matrices. Our results confirm the migration of different contaminants from wax into different bee matrices including honey, bee bread, and bee brood. The concentration of detected residues in the different matrices was significantly increased by increasing residue concentration in wax. Therefore, the maximum detected residues in the matrices were almost in wax containing high residual concentrations. Bee bread can be considered as the most important matrix due to relatively high detected concentrations and transfer ratios of the most contaminants. A significant effect of the lipophilicity of active substances on the transfer ratio into bee bread was found, which means that increasing the Log P values has positive effects on the transfer ratio. In conclusion, our results provide the first detailed information regarding the migration of active substances from wax into various matrices under realistic field conditions and are fundamentally important for assessing potential exposure and risks for honey bees.

Protective effects of bee bread on testicular oxidative stress, NF-κB-mediated inflammation, apoptosis and lactate transport decline in obese male rats

Oxidative stress, chronic inflammation and apoptosis are associated with obesity. Herein, we investigated the potential protective effect of bee bread, a natural bee product, on testicular oxidative stress, inflammation and apoptosis, as well as lactate transport in the testis of high-fat diet (HFD)-induced obese rats. Adult male Sprague-Dawley rats were either fed with normal chow (NC), HFD, HFD + bee bread (0.5 g/kg b.w./day) or HFD + orlistat (10 mg/kg b.w./day) for 12 weeks. Our results show significant decreases in the activities and mRNA expression of antioxidant genes (Nrf2, Sod, Cat and Gpx), with significant increase in pro-inflammatory (Nf-κb, Tnf-α, iNos, Il-1β) and pro-apoptotic (p53, Bax, Bax/Bcl2, Caspase-8, Caspase-9 and Caspase-3) genes in the testis of HFD group relative to the NC group. Furthermore, proliferating cell nuclear antigen (PCNA) was poorly expressed in the testis of the HFD group relative to the NC group. Similarly, the mRNA levels of glucose transporters (Glut1 and Glut3), monocarboxylate transporters (Mct2 and Mct4) and lactate dehydrogenase type C (Ldhc) decreased significantly, with decrease in lactate utilisation. Treatment with bee bread upregulated testicular antioxidant enzymes, downregulated inflammation and apoptosis, and increased PCNA immunoexpression, in addition to improving lactate transport. Taken together, our results suggest that bee bread is a promising natural product with the potential to improve male fertility.

Efficacy of Postbiotics in a PRP-Like Cosmetic Product for the Treatment of Alopecia Area Celsi: A Randomized Double-Blinded Parallel-Group Study

INTRODUCTION

Alopecia areata (AA), also known as 'area Celsi', is the second most common form of hair loss affecting the scalp. Newly proposed treatments for AA include low-level light therapy, biologics such as Janus kinase inhibitors and autologous platelet-rich plasma (PRP), which is a well-known "elixir" for hair growth. Bioactive peptides developed through biotechnological applications have been used to overcome the limitations of PRP. More recently, the involvement of microbiota in hair growth disorders, in AA in particular, has been reported, and the usefulness of microbial metabolites, i.e. postbiotics, has been suggested.

METHODS

This study was a randomized double-blinded parallel-group study in which 160 persons of both sexes affected by AA and aged between 18 and 60 years were enrolled. The subjects were randomly assigned to a treatment group (group 1), receiving the TR-PRP plus-Celsi cosmetic product, and a placebo group (group 2). The SALT (Severity of Alopecia Tool) score was determined in both groups at baseline and after 2 and 3 months of treatment, and the results compared between groups.

RESULTS

The subjects in group 1 showed a significant change from baseline in SALT score at 2 months of treatment (61.04% ± 3.45%; p < 0.0001), with a further improvement at the end of treatment (3 months) (69.56% ± 4.32%; p < 0.0001). No significant changes from baseline were reported for the subjects in group 2 (T1: 26.45% ± 3.64%; T3: 27.63% ± 7.61%).

CONCLUSIONS

The results of this study provide further proof of the efficacy of bioactive peptides that mimick the growth factors present in PRP in subjects affected by AA. They also add to our knowledge of the link between microbiota and hair growth disorders, emphasizing the importance of studies on the microbial community and microbial metabolites as a novel therapeutic approach.

Influence of land use on chlorpyrifos and persistent organic pollutant levels in honey bees, bee bread and honey: Beehive exposure assessment

This work reports the spatial and temporal variations on the dynamics of OCPs, PCBs, PBDEs and chlorpyrifos in honey bee, bee bread and honey samples, as well as soil and flowers from the surrounding areas, considering, different land uses. Honey bee samples showed the highest pollutant levels, with a predominance of the industrial contaminants over pesticides. Chlorpyrifos showed the highest concentration during the application period in almost all samples from the soybean field (S2), in concordance with its current use. By other hand, the recalcitrant compounds such as, DDTs, BDE #47 and also light PCBs exhibited the highest levels in beehive samples from the field adjacent to urban disposal waste (S3). In both soils and flower samples a prevalence of obsolete compounds over chlorpyrifos was observed, and the 6-CB predominated among the homologous groups of PCBs These results highlights the importance of soils as sink of these persistent contaminants, which became available depending on environmental conditions. Results revealed that the land uses and seasonal variations have directly impacted on the levels of agrochemicals, PCBs and PBDEs found in the beehive matrixes. This survey provides novel evidence about the current situation of pollution on honey bee colonies under temperate climates and contributes to the knowledge of this poor studied topic in Argentina.

Novel solid-state fermentation of bee-collected pollen emulating the natural fermentation process of bee bread

Structure of lactic acid bacteria biota in ivy flowers, fresh bee-collected pollen (BCP), hive-stored bee bread, and honeybee gastrointestinal tract was investigated. Although a large microbial diversity characterized flowers and fresh BCP, most of lactic acid bacteria species disappeared throughout the bee bread maturation, giving way to Lactobacillus kunkeei and Fructobacillus fructosus to dominate long stored bee bread and honeybee crop. Adaptation of lactic acid bacteria was mainly related to species-specific, and, more in deep, to strain-specific features. Bee bread preservation seemed related to bacteria metabolites, produced especially by some L. kunkeei strains, which likely gave to lactic acid bacteria the capacity to outcompete other microbial groups. A protocol to ferment BCP was successfully set up, which included the mixed inoculum of selected L. kunkeei strains and Hanseniaspora uvarum AN8Y27B, almost emulating the spontaneous fermentation of bee bread. The strict relationship between lactic acid bacteria and yeasts during bee bread maturation was highlighted. The use of the selected starters increased the digestibility and bioavailability of nutrients and bioactive compounds naturally occurring in BCP. Our biotechnological protocol ensured a product microbiologically stable and safe. Conversely, raw BCP was more exposed to the uncontrolled growth of yeasts, moulds, and other bacterial groups.

Mitigating effects of pollen during paraquat exposure on gene expression and pathogen prevalence in Apis mellifera L

Honey bee (Apis mellifera L.) populations have been experiencing notable mortality in Europe and North America. No single cause has been identified for these dramatic losses, but rather multiple interacting factors are likely responsible (such as pesticides, malnutrition, habitat loss, and pathogens). Paraquat is one of the most widely used non-selective herbicides, especially in developing countries. This herbicide is considered slightly toxic to honey bees, despite being reported as a highly effective inducer of oxidative stress in a wide range of living systems. Here, we test the effects of paraquat on the expression of detoxification and antioxidant-related genes, as well as on the dynamics of pathogen titers. Moreover, we tested the effects of pollen as mitigating factor to paraquat exposure. Our results show significant changes in the expression of several antioxidant-related and detoxification-related genes in the presence of paraquat, as well as an increase of pathogens titers. Finally, we demonstrate a mitigating effect of pollen through the up-regulation of specific genes and improvement of survival of bees exposed to paraquat. The presence of pollen in the diet was also correlated with a reduced prevalence of Nosema and viral pathogens. We discuss the importance of honey bees' nutrition, especially the availability of pollen, on colony losses chronically reported in the USA and Europe.

Antioxidant activity and protective effect of bee bread (honey and pollen) in aluminum-induced anemia, elevation of inflammatory makers and hepato-renal toxicity

Aluminum toxicity might be related to oxidative stress, and the antioxidant activity and protective effect of bee bread, which contains pollen, honey and bees' enzymes, on aluminum induced blood and hepato-renal toxicity was investigated in rats. Chemical analysis and antioxidant capacity of bee bread were conducted. The animal experiment in rats included; group 1: received distilled water (10 ml/kg b.wt), group 2: received aluminum chloride (662.2 mg/kg b.wt), group 3: received aluminum chloride (662.2 mg/kg b.wt) and ethanolic extract of the bee bread (500 mg/kg b.wt), and group 4: received aluminum chloride (662.2 mg/kg b.wt) and ethanolic extract of the bee bread (750 mg/kg b.wt). Doses were given once daily via a gavage. C-reactive protein, transaminases, urea, creatinine, creatinine clearance, sodium and potassium and urine sodium and potassium were determined on day 28 of the experiment. Bee bread contained protein, fat, fiber, ash, carbohydrate, phenol and flavonoids and it exhibited antioxidant activity. Aluminum caused a significant elevation of blood urea, transaminase, C-reactive protein and monocyte count and significantly decreased hemoglobin. These changes were significantly ameliorated by the use of bee bread. Bee bread has an antioxidant property, and exhibited a protective effect on aluminum induced blood and hepato-renal toxicity and elevation of inflammatory markers C-reactive protein, leukocyte and monocyte counts.