Gamma irradiation and ozone application as preservation methods for longer-term storage of bee pollen

Bee pollen is a healthy product with a good nutritional profile and therapeutic properties. Its high moisture content, however, promotes the growth of bacteria, molds, and yeast during storage commonly result in product degradation. Therefore, the aim of this study is to assess the effectiveness of gamma irradiation (GI) and ozone (OZ) as bee pollen preservation methods for longer storage time, as well as whether they are influenced by pollen species. To do that, GI at a dosage of 2.5, 5.0, and 7.5 kGy was applied at a rate of 0.68 kGy/h and OZ application at a concentration of 0.01, 0.02, and 0.03 g/m3 was applied for one time for 6 h, to Egyptian clover and maize bee pollen, then stored at ambient temperature for 6 months. We then determined the total phenolic content (TPC) and antioxidant activity of treated and non-treated pollen samples at 0, 3, and 6 months of storage. Total bacteria, mold, and yeast count were also evaluated at 0, 2, 4, and 6 months. Statistical analyses revealed that, TPC, antioxidant, and microbial load of both clover and maize pollen samples were significantly (p < 0.05) affected by both treatment and storage time and their interaction. Both methods were extremely effective at preserving the antioxidant properties of pollen samples after 6 months of storage at room temperature. Furthermore, the highest concentrations of both GI and OZ applications completely protected pollen samples from mold and yeast while decreasing bacterial contamination. GI at the highest dose (7.5 KGy) was found to be more effective than other GI doses and OZ application in preserving biologically active compounds and lowering the microbial count of pollen samples for 6 months. As a result, we advise beekeepers to use GI at this dose for longer-term storage.

Method optimisation for large scope pesticide multiresidue analysis in bee pollen: A pilot monitoring study

Pesticide contamination in emerging foods and supplements is currently a topic of great interest. This study focused on the evaluation of pesticide residues in commercial bee pollen samples to evaluate the risk associated with their consumption. To this end, an automated clean-up method for the pesticide extracts of bee pollen was developed. An LC-MS/MS and a GC-MS/MS method were validated for the analysis of 353 pesticides in 80 bee pollen samples purchased from different countries. The results showed the presence of 77 different pesticide residues in bee pollen, including plant protection chemicals and veterinary treatments. 85 % of the samples were contaminated with pesticides and no relevant differences were found between conventional and organic samples. Pesticide concentrations exceeding the imposed MRL were found in 40 % of the samples, but the risk assessment showed that consumers are not exposed to an unacceptable risk when consuming the evaluated bee pollen.

Analyzing the Antioxidant Activity and Fatty Acid Composition of Monofloral Mullein (Verbascum sp.) Pollen Oil obtained via Various Extraction Techniques

This study focused on characterizing fatty acids and evaluating the antioxidant properties in oils extracted from mullein (Verbascum sp.) bee-collected pollen, utilizing soxhlet and ultrasound-assisted methods with acetone and hexane solvents. Soxhlet extraction demonstrated high efficiency in mullein bee pollen oil extraction. The highest levels of total phenolic content (TPC), total flavonoid content (TFC), DPPH⋅, and ABTS⋅+ activities (41.07±1.43 mg GAE/g extract; 1.86±0.01 mg QE/g extract; 16.23±0.68 mg TE/g extract; 56.88±0.43 mg TE/g extract, respectively) were observed in oil extracted using the soxhlet method with acetone solvent. Conversely, ultrasound-assisted extraction with hexane yielded oils rich in saturated fatty acids, while acetone extraction contained higher monounsaturated fatty acids. Palmitic, linoleic, and oleic acids were predominant in the extracted oils. This study introduces, for the first time, the identification of fatty acids found in mullein bee pollen oil, along with an examination of their antioxidant properties. The choice of solvent was found to significantly influence compound extraction compared to the extraction method.

Applications of honeybee-derived products in bone tissue engineering

Nowadays, there is an increasing prevalence of bone diseases and defects caused by trauma, cancers, infections, and degenerative and inflammatory conditions. The restoration of bone tissue lost due to trauma, fractures, or surgical removal resulting from locally invasive pathologies requires bone regeneration. As an alternative to conventional treatments, sustainable materials based on natural products, such as honeybee-derived products (honey, propolis, royal jelly, bee pollen, beeswax, and bee venom), could be considered. Honeybee-derived products, particularly honey, have long been recognized for their healing properties. There are a mixture of phytochemicals that offer bone protection through their antimicrobial, antioxidant, and anti-inflammatory properties. This review aims to summarize the current evidence regarding the effects of honeybee-derived products on bone regeneration. In conclusion, honey, propolis, royal jelly, beeswax, and bee venom can potentially serve as natural products for promoting bone health.

Green and fast prediction of crude protein contents in bee pollen based on digital images combined with Random Forest algorithm

Bee pollen is considered an excellent dietary supplement with functional characteristics, and it has been employed in food and cosmetics formulations and in biomedical applications. Therefore, understanding its chemical composition, particularly crude protein contents, is essential to ensure its quality and industrial application. For the quantification of crude protein in bee pollen, this study explored the potential of combining digital image analysis and Random Forest algorithm for the development of a rapid, cost-effective, and environmentally friendly analytical methodology. Digital images of bee pollen samples (n = 244) were captured using a smartphone camera with controlled lighting. RGB channels intensities and color histograms were extracted using open source softwares. Crude protein contents were determined using the Kjeldahl method (reference) and in combination with RGB channels and color histograms data from digital images, they were used to generate a predictive model through the application of the Random Forest algorithm. The developed model exhibited good performance and predictive capability for crude protein analysis in bee pollen (R2 = 80.93 %; RMSE = 1.49 %; MAE = 1.26 %). Thus, the developed analytical methodology can be considered environmentally friendly according to the AGREE metric, making it an excellent alternative to conventional analysis methods. It avoids the use of toxic reagents and solvents, demonstrates energy efficiency, utilizes low-cost instrumentation, and it is robust and precise. These characteristics indicate its potential for easy implementation in routine analysis of crude protein in bee pollen samples in quality control laboratories.

Determination of mycobiota and aflatoxin contamination in commercial bee pollen from eight provinces and one autonomous region of China

The co-occurrence of fungi and mycotoxins in various foods has been frequently reported in many countries, posing a serious threat to the health and safety of consumers. In this study, the mycobiota in five types of commercial bee pollen samples from China were first revealed by DNA metabarcoding. Meanwhile, the content of total aflatoxins in each sample was investigated by high-performance liquid chromatography with fluorescence detection. The results demonstrated that Cladosporium (0.16 %-89.29 %) was the most prevalent genus in bee pollen, followed by Metschnikowia (0-81.12 %), unclassified genus in the phylum Ascomycota (0-81.13 %), Kodamaea (0-73.57 %), and Penicillium (0-36.13 %). Meanwhile, none of the assayed aflatoxins were determined in the 18 batches of bee pollen samples. In addition, the fungal diversity, community composition, and trophic mode varied significantly among five groups. This study provides comprehensive information for better understanding the fungal communities and aflatoxin residues in bee pollen from different floral origins in China.

Fermentation enhances the amelioration effect of bee pollen on Caco-2 monolayer epithelial barrier dysfunction based on NF-κB-mediated MLCK-MLC signaling pathway

Intestinal barrier integrity is essential for normal nutrient digestion and absorption and disease resistance. This study aims to investigate how fermentation affects the ameliorative effect of bee pollen on the intestinal barrier dysfunction stimulated by interferon-γ and tumor necrosis factor (IFN-γ/TNF-α) cytokines. The results indicated that fermentation enhances the alleviating effect of bee pollen on intestinal barrier dysfunction (including elevated trans epithelial electrical resistance and decreased paracellular permeability). In addition, fermented bee pollen (FBP) significantly decreased (p < 0.05) the secretion levels of interleukin (IL)-6, IL-8, and IL-1β and expression of cyclooxygenase (COX)-2 protein in intestinal barrier cells. Furthermore, fermentation improved the ability of bee pollen to up-regulate the expression of tight junction proteins including zonula occludens (ZO)-1, occluding, and claudin-1. Notably, FBP showed stronger ability to inhibit the expression of nuclear factor kappa-B (NF-κB) mediated myosin light chain kinase (MLCK) and myosin light chain (MLC) signaling pathway associated with phosphorylated proteins. Overall, our results indicated that fermentation enhances the protective effect of bee pollen on the intestinal barrier, and FBP has promising potential to be used as a novel functional food to protect the intestinal barrier.

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.

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.

Integrated microbiomic and metabolomic analyses reveal the mechanisms by which bee pollen and royal jelly lipid extracts ameliorate colitis in mice

Bee pollen (BP) and royal jelly (RJ) have shown therapeutic effects against colitis, but the functional components contained therein remain elusive. Here, we used an integrated microbiomic-metabolomic strategy to clarify the mechanism by which bee pollen lipid extracts (BPL) and royal jelly lipid extracts (RJL) ameliorated dextran sulfate sodium (DSS)-induced colitis in mice. Lipidomic results showed that levels of ceramide (Cer), lysophosphatidylcholine (LPC), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) were significantly higher in BPL than in RJL. The anti-inflammatory efficacy of BPL surpassed that of RJL, although both BPL and RJL could attenuate DSS-induced colitis through several mechanisms: reducing the disease activity index (DAI); decreasing histopathological damage; inhibiting the expression of genes encoding proinflammatory cytokines; improving intestinal microbial community structure, and modulating host metabolism. These findings demonstrated that BPL and RJL have great potential as functional ingredients for the production of dietary supplements to prevent early colitis.

Efficacy of Saudi propolis and bee pollen in the reduction of oxidative stress induced with CCl4 in a testis mice model

Low testosterone levels are caused by alcoholism, cigarette smoking, and exposure to toxic chemicals. This work focused on investigating the activities of propolis (PE) and bee pollen (BPE) extracts in reducing the oxidative stress of carbon tetrachloride (CCl4) in male mice models. The 48 male Swiss Albino mice weighed 27.5 ± 2.5 g and were divided into: Group1: Control (-) received distilled water only through oral intubation; Group 2: Control (- -) received corn oil by intraperitoneal (i.p.) injection once a day; Group 3: Control (+) received a sublethal dose of CCL4 intraperitoneally the end of the experiment. Group 4: Stander treated with silymarin at a daily dose of 200 mg/kg orally. Group 5: The mice were given 8.4 mg/ kg bw of (PE) orally. Group 6: The mice were given (BPE) extract (140 mg/kg bw) orally. After five consecutive days of treatment, all mice had testis injury in all groups except G1& G2, by a single i.p injection of CCL4 at a dose of 0.5 mL/kg (bw; 20% v/v in corn oil). The result showed a significant increase in luteinizing, follicle-stimulating, and testosterone hormone levels in the serum and semen parameters in the groups treated with PE and BPE. The histological results showed the greatest improvements in testis structures in the BPE group, which was confirmed using (Bcl-2; immunohistochemistry). These results suggest an important role of the antioxidative effects of PE and BPE in the attenuation of CCl4 oxidative stress.

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.

Antioxidant and anti-inflammatory activities of rape bee pollen after fermentation and their correlation with chemical components by ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry-based untargeted metabolomics

As a common food processing technology, microbial fermentation is becoming increasingly popular to promote the bioactivity of materials. This study aims to enhance rape bee pollen bioactivity through fermentation and trace the potential components associated with its bioactivity. The antioxidant and anti-inflammatory activities of unfermented bee pollen and fermented bee pollen were evaluated, and their correlation with differential metabolites was analyzed. The results indicated that fermentation significantly (p < 0.05) improved the antioxidant (>2.3-fold) and anti-inflammatory (>1.36-fold) activities of bee pollen, and increased the contents of total phenolics and flavonoids by 1.99 and 1.53 folds. Moreover, the correlation analysis results indicated that 15 components, including three phenolamides, one flavonoid aglycone, seven fatty acids, three amino acids and one ketone compound, were positively correlated with bee pollen antioxidant and anti-inflammatory activities. These results suggest that fermentation is a promising approach to increase the bioactivity of bee pollen.

Phenolamide and flavonoid glycoside profiles of 20 types of monofloral bee pollen

This study aimed at investigating phenolamides and flavonoid glycosides in 20 types of monofloral bee pollen. The plant origins of pollen samples were determined by DNA barcoding, with the purities to over 70 %. The 31 phenolamides and their 33 cis/trans isomers, and 25 flavonoid glycosides were identified; moreover, 19 phenolamides and 14 flavonoid glycosides as new-found compounds in bee pollen. All phenolics and flavonoids are present in the amidation or glycosylation form. The MS/MS cleavage modes of phenolamides and flavonoid glycosides were summarized. Isorhamnetin-3-O-gentiobioside presented the highest levels 23.61 mg/g in apricot pollen. Phenolamides in 11 types of pollen constituted over 1 % of the total weight, especially 3.9 % in rose and 2.8 % in pear pollen. Tri-p-coumaroyl spermidine and di-p-coumaroyl-caffeoyl spermidine respectively accounted for over 2.6 % of the total weight in pear and rose pollen. The richness in phenolamides and flavonoid glycosides can offer bee pollen more bioactivities as functional foods.

Concentration of essential and non-essential elements and carcinogenic / non-carcinogenic health risk assessment of commercial bee pollens from Turkey

BACKGROUND

Bee pollen, known as a natural super-food with valuable nutritional ingredients, is regarded as a good indicator of ecotoxic substances, such as potentially toxic elements (PTEs). Therefore, this study aims to examine the concentrations of selected PTEs (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Se, Sn, Sr, V, Zn) in bee pollen purchased from online markets in Turkey and perform a health risk assessment to identify the potential risk to consumers.

METHODS

The quantitative analyses were conducted by inductively coupled plasma optical emission spectrometry (ICP-OES).

RESULTS

The mean values of essential PTEs in decreasing content order were Mg > Fe > Zn > Mn > Cu > Ni > Se > Cr > Mo >Co = V. Regarding the results of the study, daily consumption (40 g for adult or 20 g for children) of commercial bee pollen can recompense 20-35 % of daily Cu, Mn, Se requirements for children, adults, pregnant, and breastfeeding women. The decreasing content order of non-essential elements was Al > Sn > Sr > Ba > Pb > As. Cadmium and Hg concentrations were below the detection limits in all the samples. In terms of food and public health; detection of the PTEs concentrations is necessary to assess the quality and safety of bee pollen before consumption. According to the carcinogenic and non-carcinogenic risk assessments; commercial pollen consumption does not pose a health risk to either children or adults for the PTEs monitored in this study.

CONCLUSION

We conclude that bee pollen is an ideal indicator for the monitoring of environmental pollution of PTEs and also a valuable source of essential elements. This study highlights the need to develop standards that regulate acceptable concentrations of PTEs.

Metabolomics reveals that phenolamides are the main chemical components contributing to the anti-tyrosinase activity of bee pollen

Bee pollen, which is known as a "full-nutrient food", has outstanding anti-tyrosinase activity. However, the chemical components contributing to this activity remain unknown. To comprehensively elucidate the chemical components of bee pollen inhibiting tyrosinase, we performed the anti-tyrosinase activity evaluation of bee pollen extract (BPE) of eight species, metabolomic analysis of chemical composition, multivariate statistical analysis and correlation analysis. The results revealed that the anti-tyrosinase activity of eight BPEs was significantly different (p < 0.05), with IC₅₀ value ranging from 10.08 to 408.81 μg/mL. A total of 725 metabolites were detected from these BPEs, and 40 differential metabolites were identified, all of which were phenolamides. All these phenolamides were positively correlated with the anti-tyrosinase activity, among which 26 phenolamides (21 spermidine derivatives and five spermine derivatives) showed particularly high correlations (r > 0.7). This is the first report to reveal the main contributor to the anti-tyrosinase activity of bee pollen.

Distribution and statistical analysis of major and trace elements in the bee pollen from the territory of Republic of Kosovo

The objective of this study was the determination of major and trace elements in the bee pollen samples from the whole territory of Republic of Kosovo. Pollen, as a natural plant product, is exposed to different contaminations absorbed by plants from the soil through the root system or with water intake, as well as to pollutants of different origins, including anthropogenic ones, deposited directly on pollen. In total 67 pollen samples were collected in 2019. The samples were analyzed for 27 macro and microelements by using ICP-AES and ICP-MS. The mean content of major elements in bee pollen was 4065, 3455, 1375 and 549 mg/kg for K, P, Ca and Mg, respectively. The range of the contents for some potentially toxic elements was 11.9-139.1, 1.9-16, 0.11-6.25, 0.01-0.329 and 0.001-0.38 mg/kg for Zn, Cu, Pb, Cd and As, respectively. Three groups of elements of mixed origin were identified through factor analysis: the first and the third Factors, are mostly of geogenic origin (Ag, Li, Al, Fe, Ca, Sr, K, Mg and P and Co, Ni, Cr, Cu and Mn) and the second Factor association is related to anthropogenic processes (Sb, As, Pb, Tl, Sn and Cd).

Phytochemical content, especially spermidine derivatives, presenting antioxidant and antilipoxygenase activities in Thai bee pollens

Background

Bee pollen (BP) is full of useful nutrients and phytochemicals.Its chemical components and bioactivities depend mainly on the type of floral pollen.

Methods

Monofloral BP from Camellia sinensis L., Mimosa diplotricha, Helianthus annuus L., Nelumbo nucifera, Xyris complanata, and Ageratum conyzoides were harvested. Crude extraction and partition were performed to yield solvent-partitioned extracts of each BP. Total phenolic content (TPC) was assayed by the Folin-Ciocalteu method, while the flavonoid content (FC) was measured by the aluminium chloride colorimetric method. Antioxidant capacity was measured by the (i) 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, (ii) 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging activity and its Trolox equivalent antioxidant capacity (TEAC), and (iii) ferric reducing antioxidant power (FRAP). All samples were tested for lipoxygenase inhibitory (LOXI) activity. The most active sample was enriched by silica gel 60 column chromatography (SiG60-CC) and high performance liquid chromatography (HPLC), observing the chemical pattern of each fraction using thin layer chromatography. Chemical structure of the most active compound was analyzed by proton nuclear magnetic resonance and mass spectrometry.

Results

Dichloromethane (DCM)-partitioned BP extracts of H. annuus L. and M. diplotricha (DCMMBP) showed a very high TPC, while DCMMBP had the highest FC. In addition, DCMMBP had the strongest DPPH and ABTS radical scavenging activities (as a TEAC value), as well as FRAP value. Also, DCMMBP (60 µg/mL) gave the highest LOXI activity (78.60 ± 2.81%). Hence, DCMMBP was chosen for further enrichment by SiG60-CC and HPLC. Following this, the most active fraction showed higher antioxidant andLOXI activities with an EC₅₀ for DPPH and ABTS of 54.66 ± 3.45 µg/mL and 24.56 ± 2.99 µg/mL (with a TEAC value of 2,529.69 ± 142.16 µmole TE/g), respectively, and a FRAP value of 3,466.17 ± 81.30 µmole Fe²⁺/g and an IC₅₀ for LOXI activity of 12.11 ± 0.36 µg/mL. Triferuloyl spermidines were revealed to be the likely main active components.

Conclusions

TPC, FC, and spermidine derivatives played an important role in the antioxidant and antilipoxygenase activities in M. diplotricha bee pollen.

Bee pollens as biological indicators: An ecological assessment of pollution in Northern Turkey via ICP-MS and XPS analyses

In this study, pollens were collected from 25 different locations of Northern Turkey to investigate pollution monitoring. Surface chemistry of pollen samples was characterized by X-ray photoelectron spectroscopy (XPS). Then the concentrations of certain elements (Li, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Ba, and Pb) in pollen samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) for the evaluation of environmental pollution. The levels of elements were detected in the following ranges (minimum-maximum, mg/kg dry pollen): Li (0.18-0.39), Al (24.98-308.04), V (6.18-98.58), Cr (1.05-6.81), Mn (13.85-95.91), Fe (52.20-326.26), Co (0.15-0.34), Ni (1.66-10.79), Cu (8.61-19.01), Zn (20.47-70.02), As (1.22-2.65), Se (0.39-0.67), Cd (0.05-0.74), Ba (0.73-16.30), and Pb (0.00-0.26). It has been concluded that there is a correlation between the pollen samples with high heavy metal concentrations and traffic density as these regions are closer to the road in the northern region. It is exposed to pollution from various sources such as intensified urbanization and tourism activities carried out on land and sea; industrial activities are increasing rapidly due to the opportunities offered by the coastal areas, sea transportation, and agricultural, domestic, and industrial pollution coming from the inner regions through rivers and streams. In this sense, pollens can be used as potential bio-indicators for monitoring heavy metal pollution and gives an idea about how we can use them for future assessing purposes.

First report of fatty acids in Mimosadiplotricha bee pollen with in vitro lipase inhibitory activity

Bee pollen (BP) is full of nutrients and phytochemicals, and so it is widely used as a health food and alternative medicine. Its composition and bioactivity mainly depend on the floral pollens. In this work, BP collected by Apis mellifera with different monoculture flowering crops (BP1-6) were used. The types of floral pollen in each BP were initially identified by morphology, and subsequently confirmed using molecular phylogenetic analysis. Data from both approaches were consistent and revealed each BP to be monofloral and derived from the flowers of Camellia sinensis L., Helianthus annuus L., Mimosa diplotricha, Nelumbo nucifera, Xyris complanata, and Ageratum conyzoides for BP1 to BP6, respectively. The crude extracts of all six BPs were prepared by sequential partition with methanol, dichloromethane (DCM), and hexane. The crude extracts were then tested for the in vitro (i) α-amylase inhibitory, (ii) acetylcholinesterase inhibitory (AChEI), and (iii) porcine pancreatic lipase inhibitory (PPLI) activities in terms of the percentage enzyme inhibition and half maximum inhibitory concentration (IC₅₀). The DCM partitioned extract of X. complanata BP (DCMXBP) had the highest active α-amylase inhibitory activity with an IC₅₀ value of 1,792.48 ± 50.56 µg/mL. The DCM partitioned extracts of C. sinensis L. BP (DCMCBP) and M. diplotricha BP (DCMMBP) had the highest PPLI activities with an IC₅₀ value of 458.5 ± 13.4 and 500.8 ± 24.8 µg/mL, respectively), while no crude extract showed any marked AChEI activity. Here, the in vitro PPLI activity was focused on. Unlike C. sinensis L. BP, there has been no previous report of M. diplotricha BP having PPLI activity. Hence, DCMMBP was further fractionated by silica gel 60 column chromatography, pooling fractions with the same thin layer chromatography profile. The pooled fraction of DCMMBP2-1 was found to be the most active (IC₅₀ of 52.6 ± 3.5 µg/mL), while nuclear magnetic resonance analysis revealed the presence of unsaturated free fatty acids. Gas chromatography with flame-ionization detection analysis revealed the major fatty acids included one saturated acid (palmitic acid) and two polyunsaturated acids (linoleic and linolenic acids). In contrast, the pooled fraction of DCMMBP2-2 was inactive but pure, and was identified as naringenin, which has previously been reported to be present in M. pigra L. Thus, it can be concluded that naringenin was compound marker for Mimosa BP. The fatty acids in BP are nutritional and pose potent PPLI activity.

Bee pollen increases hippocampal brain-derived neurotrophic factor and suppresses neuroinflammation in adult rats with chronic immobilization stress

Chronic stress is a potential problem associated with anxiety, depression, and cognitive dysfunction. Bee pollen, a powerful antioxidant, has many therapeutic effects. In this study, we aimed to examine the effects of one of the Anatolian bee pollens on depression/anxiety. 24 male Sprague Dawley rats were divided into 3 groups as control, stress, and bee pollen + stress. Bee pollen (200 mg/kg/day) was given to rats exposed to physical stress for 10 days. Open field test (OFT) and forced swimming test (FST) were applied to monitor the behavioral changes of the rats. After behavioral tests, the rats were euthanized. Brain-derived neurotrophic factor (BDNF), interleukin 1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) levels were measured by ELISA to evaluate neurological and biochemical changes in rat hippocampal tissue. In addition, malondialdehyde (MDA) and glutathione (GSH) levels in the brain were evaluated. According to the behavioral test results, bee pollen reduced anxiety-like behavior but did not affect depression-like behavior. We also found that bee pollen suppressed neuroinflammation while reducing oxidative stress and lipid peroxidation in hippocampal tissues. Moreover, bee pollen significantly increased the level of BDNF in the hippocampus. In conclusion, bee pollen reduced oxidative damage and neuroinflammation caused by immobilization stress in rat brain tissue. Therefore, we suggest that bee pollen may be an effective natural compound in alleviating the negative effects caused by immobilization stress.

Widely targeted metabolomics analysis reveals the effect of fermentation on the chemical composition of bee pollen

Microbial fermentation can break the bee pollen wall. However, the global profiling of bee pollen metabolites under fermentation remains unclear. This study aims to comprehensively elucidate the changes in the composition of bee pollen after microbial fermentation. Ultra-performance liquid chromatography-electron spray ionization-mass spectrometry (UPLC-ESI-MS) based on widely targeted metabolomics analysis was used to compare the chemical composition of unfermented bee pollen (UBP) and fermented bee pollen (FBP). Among the 890 metabolites detected, a total of 668 differential metabolites (classified into 17 categories) were identified between UBP and FBP. Fermentation significantly increased the contents of primary metabolites such as 74 amino acids and derivatives, 42 polyunsaturated fatty acids and 66 organic acids, as well as some secondary metabolites such as 38 phenolic acids, 80 flavone aglycones and 22 phenolamides. The results indicate that fermentation is a promising strategy to improve the nutritional value of bee pollen.

Cytotoxicity effect of honey, bee pollen, and propolis from seven stingless bees in some cancer cell lines

Our effort to find new material for anti cancer from natural resources leads us to focus on stingless bee products such as honey, bee pollen, and propolis. The products were from seven stingless bees named Homotrigona fimbriata, Heterotrigona itama, Heterotrigona bakeri, Tetragonula sarawakensis, Tetragonula testaceitarsis, Tetragonula fuscobalteata, Tetragonula laeviceps. The stingless bee products were evaluated for their cytotoxicity effect on MCF-7, HeLa and Caco-2 cancer cell lines. This is the first time to be reported that the honey, ethanol extracts of bee pollen and propolis of H. fimbriata displayed more potent cytotoxicity than other stingless bee products. By chromatography and biological activity-guided fractionation, ethanol extract of propolis from H. fimbriata was fractionated and isolated its active compound named mangiferonic acid. Mangiferonic acid showed a cytotoxicity effect with IC₅₀ values 96.76 µM in MCF-7, >110.04 µM in HeLa, and > 110.04 µM in Caco-2, respectively. These results exhibited the potential of ethanol extracts from propolis of H. fimbriata to be further developed for drug and experiments to verify the function are essential.

Changes of microorganism composition in fresh and stored bee pollen from Southern Germany

Analysis of plant pollen can provide valuable insights into the existing spectrum of microorganisms in the environment. When harvesting bee-collected pollen as a dietary supplement for human consumption, timely preservation of the freshly collected pollen is fundamental for product quality. Environmental microorganisms contained in freshly collected pollen can lead to spoilage by degradation of pollen components. In this study, freshly collected bee pollen was sampled at different locations and stored under various storage conditions to examine the hypothesis that storage conditions may have an effect on the composition of microorganisms in pollen samples. The samples were analyzed using 16S and 18S amplicon sequencing and characterized by palynological analysis. Interestingly, the bacterial communities between pollen samples from different locations varied only slightly, whereas for fungal community compositions, this effect was substantially increased. Further, we noticed that fungal communities in pollen are particularly sensitive to storage conditions. The fungal genera proportion Cladosporium and Mycosphaerella decreased, while Zygosaccharomyces and Aspergillus increased during storage. Aspergillus and Zygosaccharomyces fractions increased during storage at 30 °C, which could negatively impact the pollen quality if it is used as a dietary supplement.

Bee pollen powder as a functional ingredient in frankfurters

The objective of this study was to determine whether the addition of different pollen powder concentrations (0.0, 0.5, 1.0 and 1.5 g/100 g) to frankfurters had an influence on antioxidant potential and oxidative changes during storage, without detrimental effect on the quality of sausages. After cold storage of frankfurters, significant (P < 0.05) reductions of psychrotrophic bacteria populations were achieved with higher amounts of pollen (1.0 and 1.5 g/100 g). Good antioxidant properties and maintained TBARS values were accomplished by incorporating pollen into the frankfurters. In terms of quality parameters, statistically significant changes were obtained regarding the color, but sensory characteristics of the products were not disturbed. Also, the incorporation of pollen did not cause changes in terms of texture profile analyses of frankfurters. It can be concluded that the natural component, bee pollen powder, can be used as an antioxidant in frankfurter formulations, but further research is needed to estimate whether it can be an adequate replacement for synthetic antioxidants.

Natural contaminants in bee pollen: DNA metabarcoding as a tool to identify floral sources of pyrrolizidine alkaloids and fungal diversity

The use of bee pollen as a food supplement has increased in recent years as it contains several nutrients and phytochemicals. However, depending on floral composition, bee pollen can be contaminated by pyrrolizidine alkaloids (PAs), PA N-oxides (PANOs) and toxigenic fungi found in plants, which may pose a potential health risk for consumers. Thus, a DNA metabarcoding approach based on internal transcribed spacer 2 (ITS2) region was used to identify the plant sources of 17 PAs/PANOs detected by a validated method in liquid chromatography coupled to mass spectrometry (LC-MS/MS), as well as floral and fungal diversity in 61 bee pollen samples. According to LC-MS/MS analysis, 67% of the samples contained PAs/PANOs with mean concentration of 339 µg/kg. The contamination pattern was characterised by lycopsamine- and senecionine-type PAs/PANOs. PA/PANO-producing plants were identified in 54% of the PA/PANO-contaminated samples analysed by DNA metabarcoding, which also allowed identifying the overall floral and fungal composition of 56 samples. To evaluate the performance of the molecular approach, a subset of 25 samples was analysed by classical palynology. Palynological analysis partially confirmed the results of DNA metabarcoding, which had a better performance in distinguishing pollens of different genera from Asteraceae (76%) and Brassicaceae (88%). However, the molecular analysis did not identify pollens from Castanea, Eucalyptus, Hedera and Salix, which were abundant in 11 samples according to palynology. On the other hand, the molecular analysis allowed identifying several fungal genera in 33 samples, including the toxigenic fungi Alternaria and Aspergillus, which were positively correlated to the plant genus Hypericum. Despite limitations in identifying some pollen types, these preliminary results suggest that the DNA metabarcoding could be applied in a multidisciplinary approach to give a picture of floral and fungal diversity, which can be sources of natural contaminants in bee pollen and would help to control its safety.

Pesticide residues in daily bee pollen samples (April-July) from an intensive agricultural region in Southern Germany

Insect-pollinated plants are essential for honey bees to feed their brood. In agricultural landscapes, honey bees and other pollinators are often exposed to pesticides used for cultivation. In order to gain more insight into the fluctuation of pesticide loads, 102 daily pollen samples were collected between April and July 2018 in a fruit-growing area in Southern Germany. Samples were analyzed with respect to more than 260 pesticides using a multi-residue pesticide analysis method. Almost 90% of the analyzed pollen samples featured between one and thirteen different pesticides. In total, 29 pesticides were detected at maximum concentrations of up to 4500 ng/g pollen. Maximum residual concentrations of most pesticides were observed during April and the first half of May, as well as during the second half of June. In most cases, serial data of pesticide residuals were detected for approximately 10 subsequent days with two or three maximum values, which were several folds higher than concentrations on the days before and thereafter. The pollen hazard quotient (PHQ) was calculated to estimate the risk of the detected pesticides to honey bees and wild pollinators.

Screening of Indian bee pollen based on antioxidant properties and polyphenolic composition using UHPLC-DAD-MS/MS: A multivariate analysis and ANN based approach

The present investigation aims to examine the polyphenolic composition and antioxidant capacity of bee pollen samples procured from various regions of India. Total phenolic (TPC) and flavonoid (TFC) content ranged from 15.50 ± 1.25-25.63 ± 1.42 mg GAE/g and 9.72 ± 0.28-15.61 ± 0.74 mg RE/g, respectively. Coriander pollen showed the significantly (p < 0.05) higher antioxidant activity than other samples, demonstrated by DPPH radical scavenging activity (93.75 ± 0.05%), ferric reducing antioxidant power (103.98 ± 0.82 mmol Fe²⁺/g), ABTS^+• radical scavenging activity (96.58 ± 0.65%) and metal chelating activity (84.62 ± 4.37%). The observed antioxidant properties were strongly correlated with TPC and effectively predicted using artificial neural network. Sixty polyphenolic compounds including 38 flavonoids and derivatives, 21 phenolic acid and derivatives and one glucosinolates were identified using UHPLC-DAD-MS/MS wherein the presence of daidzein and sinigrin was acknowledged for the first time. Further, principal component analysis identified three principal components, illustrating 91.24% of total variation to differentiate the pollen samples which were also classified by hierarchical cluster analysis.

Effect of antioxidant-rich propolis and bee pollen extracts against D-glucose induced type 2 diabetes in rats

The present study was designed to investigate the preventive effect of propolis, bee pollen and their combination on Type 2 diabetes induced by D-glucose in rats. The study was carried out by feeding daily two concentrations (100 and 200 mg/Kg BW) of propolis or bee pollen (or their combination to normal (non-diabetic) and diabetic rats for a period of 16 weeks. In vivo biochemical changes associated to diabetes are induced by drinking a solution containing 10% of D-glucose (diabetic rats). The in vitro antioxidant activity was also evaluated and the chemical composition of propolis and bee pollen extracts was determined by UHPLC-DAD. Phytochemical composition of propolis and bee pollen revealed the presence of several natural antioxidants, such as hydroxycinnamic acids, hydroxybenzoic acids, flavonoids, flavan-3-ols and stilbens. The major antioxidant compound present in propolis was Naringin (290.19 ± 0.2 mg/Kg) and in bee pollen was apigenin (162.85 ± 17.7 mg/Kg). These results have been related with a high antioxidant activity, more intense in propolis extract. In rats, the administration of D-glucose had induced hyperglycemia (13.2 ± 0.82 mmol/L), increased plasmatic insulin levels (25.10 ± 2.12 U/L) and HOMA-IR index (14.72 ± 0.85) accompanied with dyslipidemia, elevation of hepatic enzyme levels, and a change in both serum renal biomarkers and plasmatic calcium. The co-administration of propolis and bee pollen extracts alone or in combination restored these biochemical parameters and attenuated the deleterious effects of D-glucose on liver and kidney functions. Furthermore, these effects were better attenuated in the combined therapy-prevented diabetic rats. Hence, it is possible to conclude that propolis and bee pollen can be used as a preventive natural product against diabetes induced dyslipidemia and hepato-renal damage.

The botanical origin and antioxidant, anti-BACE1 and antiproliferative properties of bee pollen from different regions of South Korea

Background

Bee pollen (BP) has been used as a traditional medicine and food diet additive due to its nutritional and biological properties. The potential biological properties of bee pollen vary greatly with the botanical and geographical origin of the pollen grains. This study was conducted to characterize the botanical origin and assess the antioxidant effects of ethanol extracts of 18 different bee pollen (EBP) samples from 16 locations in South Korea and their inhibitory activities on human β-amyloid precursor cleavage enzyme (BACE1), acetylcholinesterase (AChE), human intestinal bacteria, and 5 cancer cell lines.

Methods

The botanical origin and classification of each BP sample was evaluated using palynological analysis by observing microscope slides. We measured the biological properties, including antioxidant capacity, inhibitory activities against human BACE1, and AChE, and antiproliferative activities toward five cancer cell lines, of the 18 EBPs. In addition, the growth inhibitory activities on four harmful intestinal bacteria, six lactic acid-producing bacteria, two nonpathogenic bacteria, and an acidulating bacterium were also assessed.

Results

Four samples (BP3, BP4, BP13 and BP15) were found to be monofloral and presented four dominant pollen types: Quercus palustris, Actinidia arguta, Robinia pseudoacacia, and Amygdalus persica. One sample (BP12) was found to be bifloral, and the remaining samples were considered to be heterofloral. Sixteen samples showed potent antioxidant activities with EC₅₀ from 292.0 to 673.9 μg mL^− 1. Fourteen samples presented potent inhibitory activity against human BACE1 with EC₅₀ from 236.0 to 881.1 μg mL^− 1. All samples showed antiproliferative activity toward the cancer cell lines PC-3, MCF-7, A549, NCI-H727 and AGS with IC₅₀ from 2.7 to 14.4 mg mL^− 1, 0.9 to 12.7 mg mL^− 1, 5.0 to > 25 mg mL^− 1, 2.7 to 17.7 mg mL^− 1, and 2.4 to 8.7 mg mL^− 1, respectively. In addition, total phenol and flavonoid contents had no direct correlation with antioxidant, anti-human BACE1, or antiproliferative activities.

Conclusion

Fundamentally, Korean bee pollen-derived preparations could be considered a nutritional addition to food to prevent various diseases related to free radicals, neurodegenerative problems, and cancers. The botanical and geographical origins of pollen grains could help to establish quality control standards for bee pollen consumption and industrial production.

Room temperature solvent extraction for simple and fast determination of total concentration of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen by FAAS along with assessment of the bioaccessible fraction of these elements using in vitro gastrointestinal digestion

BACKGROUND AND AIM

Bee pollen is recognized to be a source of different nutrients, including minerals. As a food supplement, its quality and safety due to concentrations of essential macro- and microelements, and harmful trace elements has to be verified. Fast and simple element analysis of bee-collected pollen can be regarded as an important part of its quality assurance and control. The present study aimed at developping a new method for determination of selected elements (Ca, Cu, Fe, Mg, Mn, Zn) of bee pollen based on solvent extraction and completely avoiding a high temperature treatment with concentrated reagents. In addition, in vitro gastrointestinal digestion was used to assess bioavailability of elements from this food supplement.

METHODS

Bee pollen samples were dried and pulverized. Total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn were determined by flame atomic absorption spectrometry (FAAS) in sample solutions obtained by wet digestion (WD) in concentrated HNO₃ or alternatively by solvent extraction (SE) with diluted solutions of HNO₃. Gastrointestinal digestion was mimicked using simulated solutions of gastric and intestinal juices followed by determination of Ca, Cu, Fe, Mg, Mn and Zn concentrations in the bioaccessible fraction by FAAS.

RESULTS

A new simple and fast method for determination of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen was developed and validated. The method combined room temperature, two-hour SE with 0.5 mol L^-1 HNO₃ with FAAS measurements versus simple standard solutions. It provided precision within 1-5 % and trueness better than 8%, and was shown to be suitable for fast analysis of different polyfloral bee pollens. In vitro gastrointestinal digestion revealed that elements were well (70-85 % for Ca, Mg) and fairly (27-43 % for Cu, Fe, Mn, and Zn) bioaccessible from bee pollen. By pouring with water and swelling overnight, bioaccessibility of studied elements from such prepared bee pollen was increased on average by less than 15 % (Mn), 20 % (Ca, Cu, Fe, Zn) or 30 % (Mn).

CONCLUSIONS

Avoiding long-lasting, high-temperature wet digestion with concentrated reagents, the proposed sample treatment along with FAAS provided precise and true results of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen. The method was simple and fast, and enabled to analyze a higher number of samples. Simulated gastrointestinal digestion of bee pollen have shown for the first time that Ca and Mg are the most bioaccessible from this bee product. Bioaccessibility of Cu, Fe, Mg, and Zn from bee pollen are close to or lower than 40 %.

Hydrolysates from bee pollen could induced apoptosis in human bronchogenic carcinoma cells (ChaGo-K-1)

In order to examine bee pollen hydrolysates to assess their anticancer and antioxidant properties, hydrolysis of bee pollen was first performed using three different commercially available enzymes: Alcalase^®, Neutrase^®, and Flavourzyme^®. The study used DPPH and ABTS assay to evaluate the antioxidant properties of the hydrolysates obtained from bee pollen. All of the tested hydrolysates demonstrated antioxidant activity, while hydrolysate based on Alcalase^® offered a high value for IC₅₀ and was therefore chosen for further separation into five sub-fractions via ultrafiltration. The greatest antioxidant activity was presented by the MW < 0.65 kDa fraction, which achieved an IC₅₀ value of 0.39 ± 0.01 µg/mL in the DPPH assay and 1.52 ± 0.01 µg/mL for ABTS. Purification of the MW < 0.65 kDa fraction was completed using RP-HPLC, whereupon the three fractions from the original six which had the highest antioxidant activity underwent further examination through ESI-Q-TOF-MS/MS. These particular peptides had between 7 and 11 amino acid residues. In the case of the MW < 0.65 kDa fraction, testing was also carried out to determine the viability of lung cancer cell lines, represented by ChaGo-K1 cells. Analysis of the antiproliferative properties allowed in vitro assessment of the ChaGo-K1 cells' viability following treatment using the MW < 0.65 kDa fraction. Flow-cytometry generated date which revealed that it was possible for the MW < 0.65 kDa fraction to induce apoptosis in the ChaGo-K1 cells in comparison to the results with cells which had not been treated.

Bee Pollen Supplementation to Aged Horses Influences Several Blood Parameters

In humans and animals, aging leads to a decrease in immune function and an increased susceptibility to infection. Decreased immunity and an increase in the incidence of infectious diseases are particularly notable during the autumn. Bee pollen supplementation improves immunity and antioxidant enzyme activity, as well as general performance. The aim of this study was to evaluate the effects of bee pollen supplementation during the autumn on blood parameters in aged horses. The study was performed on 16 warmblood horses aged 15-26 years. Half of this group received 60 g of bee pollen (soaked in water) daily for 30 days during the autumn season. Blood samples were taken from all horses before and after the supplementation period. Numerous hematological and plasma biochemical parameters including indicators of oxidative stress were determined. The data collected after the supplementation were compared with data collected before the experiment using one-way analysis of variance and paired Student's t-test. In the control group, there was a decline in the total number of red blood cells, hemoglobin, and hematocrit and an increase in some lipid parameters, urea, total plasma proteins, and sulfhydryl groups. Supplementation with bee pollen prevented the variation of these parameters, except for low-density lipoprotein cholesterol. We believe that bee pollen supplementation for aged horses during autumn has beneficial effects because it inhibited some of the adverse changes observed in the control horses during this season.

exhibit a higher in vitro antityrosinase activity than kojic acid

Background

Ozone deterioration in the atmosphere has become a severe problem causing overexposure of ultraviolet light, which results in humans in melanin overproduction and can lead to many diseases, such as skin cancer and melasma, as well as undesirable esthetic appearances, such as freckles and hyperpigmentation. Although many compounds inhibit melanin overproduction, some of them are cytotoxic, unstable, and can cause skin irritation. Thus, searching for new natural compounds with antityrosinase activity and less/no side effects is still required. Here, bee pollen derived from sunflower (Helianthus annuus L.) was evaluated.

Materials and methods

Sunflower bee pollen (SBP) was collected from Apis mellifera bees in Lopburi province, Thailand in 2017, extracted by methanol and sequentially partitioned with hexane and dichloromethane (DCM). The in vitro antityrosinase activity was evaluated using mushroom tyrosinase and the half maximal inhibitory concentration (IC₅₀) is reported. The antioxidation activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and reported as the half maximal effective concentration. Two pure compounds with antityrosinase activity were isolated by silica gel 60 column chromatography (SG₆₀CC) and high performance liquid chromatography (HPLC), and their chemical structure deduced by Nuclear Magnetic Resonance (NMR) analysis.

Results

The DCM partitioned extract of SBP (DCMSBP) had an antityrosinase activity (IC₅₀, 159.4 μg/mL) and was fractionated by SG₆₀CC, providing five fractions (DCMSBP1-5). The DCMSBP5 fraction was the most active (IC₅₀ = 18.8 μg/mL) and further fractionation by HPLC gave two active fractions, revealed by NMR analysis to be safflospermidine A and B. Interestingly, both safflospermidine A and B had a higher antityrosinase activity (IC₅₀ of 13.8 and 31.8 μM, respectively) than kojic acid (IC₅₀ of 44.0 μM). However, fraction DCMSBP5 had no significant antioxidation activity, while fractions DCMSBP1-4 showed a lower antioxidation activity than ascorbic acid.

Conclusion

Safflospermidine A and B are potential natural tyrosinase inhibitors.

Simultaneous determination of carvacrol and thymol in bee pollen by using a simple and efficient solvent extraction method and gas chromatography-mass spectrometry

A novel method is proposed to determine residues of carvacrol and thymol in bee pollen by means of gas chromatography coupled to mass spectrometry. This is an efficient and simple sample treatment (with average analyte recoveries between 90% and 104%) involving solvent extraction with hexane followed by evaporation. There is no need for any additional clean-up step, as the matrix did not affect determination of mass spectrometry for either compound. The chromatographic conditions are also optimized: a ZB-WAX column is employed, helium is the carrier gas at a flow rate of 1.1 mL/min, and a temperature program is included, allowing baseline separation of both compounds in less than 21 min. The method is fully validated in terms of selectivity, limits of detection and quantification, matrix effect, linearity, precision and trueness. Results show that not only is it selective, but that it also displays a wide linearity range (limit of quantification-1000 μg/kg), good precision (relative standard deviation values lower than 8%) and sensitivity (limits of detection and quantification lower than 15 μg/kg). Finally, several bee pollen samples are analysed, and thymol and carvacrol residues are found at low concentrations (limit of quantification-57 μg/kg) in some cases.

Pyrrolizidine alkaloids in bee pollen identified by LC-MS/MS analysis and colour parameters using multivariate class modeling

Toxic pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) can be present in bee pollen depending on the plants visited by bees. A liquid chromatography-mass spectrometry (LC-MS/MS) method was developed and validated to monitor 17 PAs/PANOs in 44 bee pollens. The CIE-L∗a∗b∗ colour coordinates with the specular component either included or excluded were recorded in pellets and ground aliquots. Lightness (L∗) and yellowness (b∗) of ground bee pollen were significantly correlated to PAs/PANOs content. The L∗ and b∗ cut-offs sorted by a receiver operating characteristic analysis to predict PAs/PANOs presence showed a significant increase in the relative risk to detect amounts higher than 84 μg kg-1. Two supervised canonical discriminant analyses confirmed that pollen without PAs could be distinguished from those containing PAs/PANOs. The data suggest that instrumental colour coupled with supervised models could be used as a screening test for PAs/PANOs in bee pollen, before the confirmatory LC-MS/MS analysis.

Anti-inflammatory and anti-angiogenesis effect of bee pollen methanolic extract using air pouch model of inflammation

BACKGROUND AND PURPOSE

Research on new drugs with a natural source and low side effects is a priority in pharmacology studies. The present study was conducted to investigate the anti-inflammatory and anti-angiogenesis effects of bee pollen extract in the air pouch model of inflammation.

EXPERIMENTAL APPROACH

To achieve this goal, male rats were moderately anesthetized and then 20 and 10 mL of sterile air were subcutaneously injected into the intrascapular area of the back of the rat on first and third days, respectively. On day 6, inflammation was induced by intrapouch injection of carrageenan. Normal saline in the control group and bee pollen methanolic extract (50, 100, and 200 mg/pouch) were administered at day 6, simultaneously with carrageenan, and then for 2 consecutive days only normal saline and the extracts were injected. Following sacrificing the rats the pouch was opened and the exudate volume, leukocyte accumulation, granulation tissue weight, vascular endothelial growth factor (VEGF), interleukin 1beta, and tumor necrosis factor alpha (TNF-α) concentrations were determined 3 days after induction of inflammation. In order to investigate the angiogenesis, the granulation tissue was removed, homogenized in the Drabkin's reagent, and then centrifuged. The supernatant was filtered and the hemoglobin concentration was determined using a spectrophotometer.

RESULTS

Bee pollen extract significantly decreased the exudate volume, leukocyte accumulation, granulation tissue weight, angiogenesis, VEGF, and TNF-α concentration.

CONCLUSION AND IMPLICATIONS

The findings of the current study revealed that bee pollen methanolic extract has an anti-inflammatory and anti-angiogenesis effect, which could be attributed to the inhibition of VEGF and TNF-α production in the inflammatory exudates.

The therapeutic and protective effects of bee pollen against prenatal methylmercury induced neurotoxicity in rat pups

The current study evaluated the protective and therapeutic potency of bee pollen in ameliorating the toxic effects of methylmercury (MeHg), by measuring certain biochemical parameters related to neurotransmission, neuroinflammation, apoptosis, and glutamate excitotoxicity in the male neonate brain. Healthy, pregnant female rats (N = 40) were randomly divided into 5 groups, each comprising10 male neonates, as follows: (i) neonates delivered by control mothers; (ii) neonates delivered by MeHg-treated mothers who received 0.5 mg/kg BW/day MeHg via drinking water from gestational day 7 till postnatal day 7; (iii) neonates delivered by bee pollen treated mothers who received 200-mg/kg BW bee pollen from postnatal day 0 for 4 weeks; (iv) protective group of neonates delivered by MeHg and bee pollen-treated mothers, who continued to receive bee pollen until day 21 at the same dose, and (v) therapeutic group of neonates delivered by MeHg- treated mothers followed by bee pollen treatment, wherein they received 200-mg/kg BW bee pollen from postnatal day 0 for 4 weeks. Selected biochemical parameters in brain homogenates from each group were measured. MeHg-treated groups exhibited various signs of brain toxicity, such as a marked reduction in neurotransmitters (serotonin (5-HT), nor-adrenalin (NA), dopamine (DA)) and gamma aminobutyric acid (GABA) and elevated levels of interferon gamma (IFN-γ), caspase-3, and glutamate (Glu). Bee pollen effectively reduced the neurotoxic effects of MeHg. Minimal changes in all measured parameters were observed in MeHg-treated animals compared to the control group. Therefore, bee pollen may safely improve neurotransmitter defects, inflammation, apoptosis, and glutamate excitotoxicity.

[Sebotropic drug eruption after ingestion of bee pollen]

INTRODUCTION

The medical literature contains five cases of exanthema with sebaceous tropism induced by consumption of kava-kava extract filed under the name of sebotropic drug reaction. Herein we report a new case following consumption of bee pollen.

PATIENTS AND METHODS

A 37-year-old man consulted for erythemato-papular and fixed plaques of the face, upper trunk and shoulders present for 3 days. Standard blood tests were normal except for neutrophil leukocytosis at 9.8 G/l and eosinophilia at 1.4 G/l. Cutaneous biopsy of a facial plaque revealed folliculocentric lesions with necrosis of sebocytes in the sebaceous gland, associated with an eosinophil-rich infiltrate. The patient had begun consuming bee-pollen granules 3 weeks before the onset of symptoms. The rash regressed within 3 weeks of cessation of pollen consumption. Patch tests (ICDRG battery, propolis 1% Vaseline dilution and bee pollen provided by the patient, both pure and in a 30% dilution in Vaseline) were negative at 48 and 72h.

DISCUSSION

The clinical-pathological correlation was consistent with a diagnosis of sebotropic drug reaction induced by the consumption of bee pollen. The diagnosis was based on papular exanthema of the seborrheic zones occurring 2 to 3 weeks after initial intake of the offending substance, with histological evidence of inflammatory necrosis of the sebaceous glands.

CONCLUSION

We report what is to our knowledge the first case of sebotropic drug reaction following ingestion of bee pollen.

Effect of bee pollen on growth performance, carcass traits, blood parameters, and the levels of metabolic hormones in New Zealand White and Rex rabbits

The aim was to evaluate the effect of bee pollen (BP) on performance, blood parameters, and metabolic hormones in New Zealand White (NZW) and Rex (RX) rabbits. A total of 60 six-week-old rabbits were allotted into a completely randomized design in a 2 × 3 factorial arrangement (two breeds and three levels of BP: 0, 250, and 350 mg/kg body weight). The effects of breed × BP supplementation level were non-significant for all growth performance and carcass traits, as well as the concentrations of metabolic hormones in the plasma. Meanwhile, some blood parameters (hemoglobin, packed cell volume, alanine aminotransferase, aspartate aminotransferase, and urea) were significantly affected (P < 0.05). Regardless of the effect of breed, the supplementation of BP at a dose of 350 mg/kg BW increased the final body weight (P = 0.008), average daily gain (P < 0.001), and net profits (P = 0.006). However, the rabbits treated with BP at a dose of 250 mg/kg BW showed lower average daily feed intake (- 14.45 g/d; P = 0.049) and feed to gain ratio (- 0.48; P = 0.039). In both rabbit breeds, BP at a dose of 350 mg/kg increased the concentrations of insulin-like growth factor-1 (302.62 ng/ml, P < 0.001), insulin (16.63 ng/ml, P = 0.050), and triiodothyronine (158.50 ng/dl, P < 0.001) in plasma compared with other groups. It may be concluded that intake of BP supplementation can improve the feed to gain ratios, blood indices, and metabolic hormones in different rabbit breeds. However, the appropriate dosage and the route of supplementation of BP in broiler rabbits need further research.

Use of Multiflora Bee Pollen as a Flor Velum Yeast Growth Activator in Biological Aging Wines

Flor velum yeast growth activators during biological aging are currently unknown. In this sense, this research focuses on the use of bee pollen as a flor velum activator. Bee pollen influence on viable yeast development, surface hydrophobicity, and yeast assimilable nitrogen has already been studied. Additionally, bee pollen effects on the main compounds related to flor yeast metabolism and wine sensory characteristics have been evaluated. “Fino” (Sherry) wine was supplemented with bee pollen using six different doses ranging from 0.1 to 20 g/L. Its addition in a dose equal or greater than 0.25 g/L can be an effective flor velum activator, increasing yeast populations and its buoyancy due to its content of yeast assimilable nitrogen and fatty acids. Except for the 20 g/L dose, pollen did not induce any significant effect on flor velum metabolism, physicochemical parameters, organic acids, major volatile compounds, or glycerol. Sensory analysis showed that low bee pollen doses increase wine’s biological aging attributes, obtaining the highest score from the tasting panel. Multiflora bee pollen could be a natural oenological tool to enhance flor velum development and wine sensory qualities. This study confirms association between the bee pollen dose applied and the flor velum growth rate. The addition of bee pollen could help winemakers to accelerate or reimplant flor velum in biologically aged wines.

Determination of metals as bio indicators in some selected bee pollen samples from Jordan

This study was done to determine the degree of metals and heavy metals in some bee pollen sample as biological indicator for environmental pollution. Sample were collected from industrial, urban and agricultural areas of Jordan in year 2017. Eight metals (As, Cd, Cu, Mg, Pb, Ni, Se, and Zn) continents analyzed by using Inductively Coupled Plasma Optical Emission Spectrum, (ICP-OES).

Results were statistically interpreted by using ANOVA analysis. Metals content in bee pollen from Jordan and China were determined within the following ranges (minimum–maximum mg/kg); Cu (copper): 11.338–0.032, Zn (Zinc): 77.022–25.24, Ni (Nickel): 2.839 to <0.01, Se (Selenium): 3.03 to <0.04, Mg (Magnesium): 1575.19–641.388, Pb (Lead): 2.567 to <0.03, Cd (Cadmium): <0.005, As (Arsenic): <0.02. The results showed that there were no statistically significant differences among metals in the bee pollen. It has also found that bee pollen produced in Jordan may be a good source of some trace elements like Se and Mg and can be used as an environmental indicator and for quality control.

Ameliorative effect of probiotics (Lactobacillus paracaseii and Protexin®) and prebiotics (propolis and bee pollen) on clindamycin and propionic acid-induced oxidative stress and altered gut microbiota in a rodent model of autism

Colonization by toxin-producing bacteria in the gut plays a major role in bowel problems in autistic patients. Prebiotics can inhibit the growth of these pathogenic microbes by nourishing beneficial bacteria, while probiotics--live microorganisms--can balance the gut bacteria; thus, both together can maintain healthy bacteria in the gut. The present study was conducted to find the effect of probiotics and prebiotics in balancing the gut flora in a rodent model of autism linked with a clindamycin-induced altered gut. The effects of probiotics and prebiotics on oxidative stress markers in the brain were also evaluated. Eight groups of hamsters were assigned, with Group I serving as the control; Group II, as the autistic model, was treated with 250 mg propionic acid/kg BW/day for 3 days; Group III was treated with clindamycin 30 mg/kg BW for 3 days; Groups IV and V were treated with bee pollen and propolis (supposed prebiotics) at a dose of 250 mg/kg BW/day for 28 days; Group VI and Group VII were treated with Lactobacillus paracaseii and Protexin® (supposed probiotics) for 28 days; and finally, Group VIII was anorectally transplanted with stool from normal animals for 5 days. Remarkable changes were measured in oxidative stress markers, primarily glutathione and vitamin C, in the brains of hamsters in the propionic acid- and clindamycin-treated group. All probiotic/prebiotic treatments showed ameliorative effects; however, lactobacillus had the strongest effect. We conclude that pro-and prebiotic supplements may be effective to revive healthy digestive system function in autistic patients. The disappointing results of the fecal transplants suggest that further study is needed to develop an appropriate technique.

Analysis of Multifloral Bee Pollen Pellets by Advanced Digital Imaging Applied to Functional Food Ingredients

Bee pollen is a hive product, resulting from floral pollen agglutination by worker bees and it is characterized by its excellent bioactive and nutritional composition. Currently, research is focused on bee pollen applications on food industry, because this product has been considered an excellent source of compounds for human nutrition. It is also important in some industries, where color and particle size are important characteristics for production. Due to the granular nature of bee pollen, conventional colorimetry does not allow describing color correctly; thus, digital image analysis is a better alternative. This technique could also allow classifying bee pollen according to its appearance beyond the color. Consequently, the aim of this work was to develop a novel methodology for image data processing to classify bee pollen as ingredient in food industry. Seven color groups in samples were established regarding harvest month and particle size. It was possible to calculate the percentage of each color group in all samples. This methodology also allowed selecting each fraction for different applications in food industry using colorimetry, granulometry and the relationship between both of them.

Application to bee pollen

Two new polymer-based stationary phases; DCpak PBT (poly(butylene terephthalate)) and DCpak P4VP (poly(4-vinylpirydine)) were evaluated for the analysis of polyphenols using supercritical fluid chromatography (SFC). The compounds studied included phenolic acids and flavonoids. The different variables that influence the chromatographic separation, such as type and percentage of organic modifier, additive, pressure and temperature were examined. Using the DCpak P4VP column the retention was exceptionally high, obtaining better results with the DCpak PBT column. The separation of nine polyphenols was achieved using a gradient of modifier (methanol with 0.1% trifluoroacetic acid) from 5 to 50%, a pressure of 150 bar, a temperature of 35 °C and a flow-rate of 2 mL/min. The use of additives was necessary in order to obtain good peak shapes and efficiencies, achieving the best results with trifluoroacetic acid. LODs and LOQs values were lower than 5 μg/mL in all the cases; meanwhile, the %RSD values for method repeatability and inter-day reproducibility were lower than 3% and 10% respectively. Finally, the proposed method was successfully applied to the analysis of polyphenols in commercial bee pollen; four compounds, namely cinnamic acid, p-coumaric acid, catechin and quercetin were identified and quantified.

Polyamine derivatives from the bee pollen of Quercus mongolica with tyrosinase inhibitory activity

Eighteen constituents, including nine new compounds, were isolated from the bee pollen of Quercus mongolica. The structures of the new compounds were established on the basis of combined spectroscopic analysis. Structurally, the nine new compounds are polyamine derivatives with phenolic moieties which were assigned as one putrescine derivative, mogolicine A (2), seven spermidine derivatives, mongolidines A-G (3-5, 8, 12, 14, 17) and one spermine derivative, mogoline A (18). Evaluation of the biological activity of isolated compounds revealed that the polyamine derivatives with coumaroyl and caffeoyl moieties showed tyrosinase inhibition with IC₅₀ values of 19.5-85.8 μM; however, the addition of a methoxy group to phenolic derivatives reduced the inhibitory activity.

Evaluation of the use of multiflora bee pollen on the volatile compounds and sensorial profile of Palomino fino and Riesling white young wines

This study investigates the impact of bee pollen on volatile compounds, odour activity values and sensory profiles in Palomino fino and Riesling young white wines. Commercial bee pollen was added to grape must using six different doses (0 (control), 0.1, 0.25, 1, 5, 10 and 20g/L) and fermented under controlled conditions. Volatile compounds were determined with GC and GC-MS chromatography and sensorial analysis using a qualified panel of tasters. Bee pollen produces an increase in volatile compounds depending on the grape variety and the dose applied. It also increases the synthesis of higher alcohols, methanol, esters, acetaldehyde and terpenes, reducing alcohols and fatty acids. Wines with low doses (0.1 and 0.25g/L) showed the higher OAV values (fruity and floral) and scores in overall judgment for the sensory evaluation. High pollen doses decrease fruity character and could result in deviations affecting the sensorial quality.

Ameliorative effects of bee pollen and date palm pollen on the glycemic state and male sexual dysfunctions in streptozotocin-Induced diabetic wistar rats

This study aimed to assess the effects of bee pollen (BP) and/or date palm pollen (DPP) suspensions on the glycemic state, testicular dysfunctions, oxidative stress and antioxidant defense system in streptozotocin (STZ)-induced diabetic male Wistar rats. Diabetes mellitus was induced by single intraperitoneal injection of STZ to overnight-fasted rats at dose of 40mg/kg body weight. After 1 week of STZ injection, diabetic rats were treated with BP and/or DPP suspensions at dose levels of 100mg/kg body weight/day for 4 weeks. The STZ-induced diabetes significantly increased blood glucose levels and testicular nitric oxide (NO) and malondialdehyde (MDA) levels parallel with disrupted testicular and pancreatic histological architecture and integrity. On the other hand, STZ-induced diabetes significantly decreased body weight, testis and pancreas weights, levels of serum insulin, testosterone, luteinizing hormone (LH) & follicle stimulating hormone (FSH) as well as sperm count, motility and viability. The administration of BP and DPP suspensions resulted in a significant recovery of the above mentioned parameters as compared to the diabetic control group. These improvements were associated with enhancement of the testicular antioxidant system manifested by an increase in the lowered glutathione content (GSH) and glutathione-S-transferase (GST), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in diabetic rats as a result of treatments with BP and DPP suspensions. Thus, it can be concluded that BP and/or DPP suspensions may have potential protective role against diabetes-induced pituitary testicular axis dysfunction and testicular histological deleterious changes in association with antihyperglycemic actions via their antioxidant properties and their efficiency to improve blood insulin level and beta cell function.

UPLC-Q-Exactive Orbitrap/MS-Based Lipidomics Approach To Characterize Lipid Extracts from Bee Pollen and Their in Vitro Anti-Inflammatory Properties

Bee pollen (BP) is collected by honeybees from flower pollen mixed with nectar and its secretions with extensive nutritional and therapeutic properties. Lipids are known to be critical contributors for the therapeutic effects of BP and vary depending on different plant sources; however, lipid profiles of BP are not available. Here, an UPLC-Q-Exactive Orbitrap/MS method was established for comprehensive lipidomics analysis of BP derived from three major nectar plants (Brassica campestris L., Camellia sinensis L., and Nelumbo nucifera Gaertn.). A total of nine lipid classes, including phosphatidylcholine (41 species), phosphatidylethanolamine (43 species), phosphatidylglycerol (9 species), phosphatidylserine (10 species), lysophosphatidylcholine (12 species), ceramide (8 species), diglyceride (27 species), triglyceride (137 species), and fatty acids (47 species), were first identified and quantified in the three BPs. In vitro anti-inflammatory activity was also discovered in the lipid extracts of three BPs, which has potential relevance to the abundance of phospholipids and unsaturated fatty acids in BP. Our comprehensive lipidomics profiling and in vitro anti-inflammatory properties of BP provide evidence for its future application.

Extraction and determination of bioactive compounds from bee pollen

Since ancient times bee pollen has been considered a good source of bioactive substances and energy. Taking into account the current demand for healthy and natural foods, it is not surprising that bee pollen has been attracting commercial interest in recent years, making it one of the most widely consumed food supplements. It has been extensively reported that bee pollen contains several health-promoting compounds, such as proteins, amino acids, lipids, phenolic compounds, vitamins or minerals. Thus, this study aims to give an overview of the extraction and determination techniques of several of the above-mentioned compounds which have been published in the last few years (2011-2017). The design of the study is in accordance with the different families of bioactive compounds, and the extraction procedures together with the analytical techniques employed and their determination are discussed. A list of some of the most relevant applications is provided for each category, including a brief summary of the experimental conditions. The references included will provide the reader with a comprehensive overview of and insight into the analysis of bioactive compounds from bee pollen.