Royal jelly has estrogenic effects in vitro and in vivo

Royal jelly (RJ), a creamy substance secreted by honeybees, is the exclusive diet for queen bee differentiation and life maintenance. RJ has been used in cosmetics, beverages, medicines, and supplements worldwide. However, allergy is a concerning issue for RJ, especially in atopic dermatitis (AD) and asthma patients. In some cases, allergic reactions are seen after the first intake of RJ, suggesting the existence of allergens cross-reactive with RJ. Information about the cross-reactive allergens is very important for the safe application of RJ; however, study of this cross-reactivity is quite limited. In this study, we attempted to identify allergens cross-reactive with RJ by using serum samples from 30 AD patients who had never been exposed to RJ. In an enzyme-linked immunosorbent assay (ELISA) experiment, RJ-binding IgE antibodies were detected in the serum of 10 out of 30 patients, and their antibody titers ranged from 4- to 2,048-fold dilution ratios. Additionally, 3 AD patients were determined to be positive in a skin-prick test (SPT) with an RJ solution. Significant correlations were observed between the anti-RJ antibody titer and nonspecific IgE and between the anti-RJ antibody titer and the Eczema Area and Severity Index score. We further examined the cross-reactivity between RJ and 14 typical allergens by using an ELISA-inhibition assay and demonstrated that the following 6 allergens showed cross-reactivity with RJ: the European house dust mite (HDM) (Dermatophagoides pteronyssinus), American HDM (Dermatophagoides farinae), snow crab (Chionocetes spp.), edible crab (Cancer pagurus), German cockroach (Blatella germanica), and honeybee venom (Apis mellifera). In conclusion, people with a history of allergic diseases, including AD, asthma, and allergic rhinitis, should be cautioned against consuming RJ products because of the potential for cross-reactive responses to ensure the safe and successful use of RJ supplements.

BackgroundNon-healing wounds have been a severe issue in the global healthcare system. Regrettably, royal jelly, a traditional remedy for various skin injuries, has not been widely applied in cutaneous wounds in clinical practice nowadays, which may be due to the confusion and the lack of knowledge about the efficacies of different types of royal jelly, the bioactive constituents, and the precise mechanisms underlying the wound repairing activity. Since the compositions and bioactivities of royal jelly are predominantly influenced by nectar plants, this study aims to explore the differences in the wound-healing properties of royal jelly produced by Apis mellifera L. during the blossom seasons of different floral sources, to provide guidelines for the future rational application of royal jelly in cutaneous wounds, and to promote the further discovery of wound repair-promoting substances.MethodsRoyal jelly samples were harvested during flowering seasons of Castanea mollissima Bl. (chestnut) and Brassica napus L. (rapeseed) in South China, from which hydrophilic and lipophilic fractions were extracted. The in vivo wound-healing potential was preliminarily assessed in Wistar rats’ excisional full-thickness wounds, followed by investigating the mechanisms of action through in vitro assays with human epidermal keratinocytes and LPS-stimulated inflammation in macrophages.ResultsThe results indicated that different royal jelly samples exhibited distinct wound-healing potential, in which Castanea mollissima Bl. royal jelly was more potent. It sped up wound closure between day 2 and day 4 to 0.25 cm2/day (p < 0.05), and could accelerate wound repair by enhancing the proliferative and migratory capabilities of keratinocytes by 50.9% (p < 0.001) and 14.9% (p < 0.001), modulating inflammation through inhibiting nitric oxide production by 46.2% (p < 0.001), and promoting cell growth through increasing the secretion of transforming growth factor-β by 44.7% (p < 0.001). In contrast, Brassica napus L. royal jelly could regulate inflammation by reducing the amount of tumour necrosis factor-α by 21.3% (p < 0.001).ConclusionsThe present study improves the application of royal jelly for curing difficult-to-heal wounds, in which the hydrosoluble extract of Castanea mollissima Bl. royal jelly promises the greatest potential. It also provides clues which may lead towards the identification of substances derived from royal jelly to treat wounds.

BackgroundHoney bees are not only essential for pollination services, but are also economically important as a source of hive products (e.g., honey, royal jelly, pollen, wax, and propolis) that are used as foods, cosmetics, and alternative medicines. Royal jelly is a popular honey bee product with multiple potential medicinal properties. To boost royal jelly production, a long-term genetic selection program of Italian honey bees (ITBs) in China has been performed, resulting in honey bee stocks (here referred to as RJBs) that produce an order of magnitude more royal jelly than ITBs. Although multiple studies have investigated the molecular basis of increased royal jelly yields, one factor that has not been considered is the role of honey bee-associated gut microbes.ResultsBased on the behavioral, morphological, physiological, and neurological differences between RJBs and ITBs, we predicted that the gut microbiome composition of RJBs bees would differ from ITBs. To test this hypothesis, we investigated the bacterial composition of RJB and ITB workers from an urban location and RJBs from a rural location in China. Based on 16S rRNA gene profiling, we did not find any evidence that RJBs possess a unique bacterial gut community when compared to ITBs. However, we observed differences between honey bees from the urban versus rural sites.ConclusionsOur results suggest that the environmental factors rather than stock differences are more important in shaping the bacterial composition in honey bee guts. Further studies are needed to investigate if the observed differences in relative abundance of taxa between the urban and rural bees correspond to distinct functional capabilities that impact honey bee health. Because the lifestyle, diet, and other environmental variables are different in rural and urban areas, controlled studies are needed to determine which of these factors are responsible for the observed differences in gut bacterial composition between urban and rural honeybees.

Royal jelly (RJ) is a glandular secretion fed to developing honey bee larvae by adult worker bees. It is also a potential source of disease transmission in and between honey bee colonies. We endeavored to characterize the microbiome, virome, and other biota present in RJ via an integrated meta-omics approach. Using a magnetic beads-based extraction protocol, we identified eDNA and eRNA fragments from organisms of interest in RJ using high-throughput metagenomics (DNA-seq), metatranscriptomics (total RNA-seq), and parallel sequencing. This allowed us to enhance the detection of Operational Taxonomic Units (OTUs) undetectable by standard 'omics or amplicon protocols'. Using this integrated approach, we detected OTUs present in RJ from honey bee pests and pathogens, including Melissococcus plutonius, Paenibacillus larvae, Varroa destructor, V. jacobsoni, Aethina tumida, Galleria mellonella, Vairimorpha ceranae, Apis mellifera filamentous virus, Black queen cell virus, Acute bee paralysis virus, Sacbrood virus, Deformed wing virus, Israeli acute bee paralysis virus, Kashmir bee virus, and Slow bee paralysis virus, as well as multiple beneficial gut bacteria from the genera Lactobacillus, Actinobacteria, and Gluconobacter. The presence of DNA and RNA from these organisms does not conclusively indicate the presence of live organisms in the RJ, but it does suggest some exposure of the RJ to these organisms. The results present a comprehensive eDNA and eRNA microbial profile of RJ, demonstrating that our novel method is an effective and sensitive molecular tool for high-resolution metagenomic and metatranscriptomic profiling, and is of value for detection of pathogens of concern for the beekeeping industry.

RADIATION therapy is associated with a risk of long-term adverse effects. Royal jelly (RJ), a natural product extracted from honey bees is rich in compounds with many biological activities. This study aims at evaluating the role of RJ against gamma-radiation induced liver injury. Twenty-four male albino rats were divided into four groups. Control, IRR: whole-body exposed to gamma radiation (3 Gy every 3 days up to 9 Gy), RJ: received RJ by gavages (250 mg/kg BW) during 15 days, RJ+IRR: received RJ before the 1st radiation fraction and the treatment continued for 14 days. Animals were sacrificed one day post the last RJ dose. The results revealed that RJ significantly reduced the radiation-induced increases in liver malondialdehyde MDA, protein carbonyl CO, and 8-hydroxy-2-deoxyguanosine (8-OHdG), markers of lipid, protein and DNA oxidation, accompanied by significant elevations of glutathione content (GSH) and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. A significant reduction in the elevation of liver DNA fragmentation and caspase-3 activity was also recorded. In the serum, the level of the inflammatory markers, tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) and the level of the fibrotic markers collagen IV and laminin were significantly lower than their corresponding values in irradiated rats. The amelioration in the extent of liver injury obtained by RJ treatment was substantiated by significant improvement of liver functions verified by lowering the activity levels of liver function enzymes. It could be concluded that RJ by suppressing oxidative stress and decreasing inflammatory, apoptotic and fibrotic markers may alleviate the progression of radiation-induced liver injury.

Royal jelly is a glandular secretion produced by Apis mellifera L. bees, it is considered as a functional food with the ability to control and prevent chronic diseases such as high blood pressure, because in their composition there are peptides with biological activity; however, different investigations indicate that the composition of amino acids in royal jelly can be affected by the diet consumed by bees, which could influence the presence of peptides. The main objective of this study was to evaluate the effect of the food consumed by honey bees on the antihypertensive potential of the royal jelly produced. Honey bee colonies were fed with three different diet treatments: Mucuna pruriens flour and honey; pollen and honey and free feeding. The amino acid content was determined in the protein ingredients and the royal jelly obtained by every feed treatment. The antihypertensive activity was evaluated in vitro by the angiotensin converting enzyme technique. To assess the antihypertensive activity in vivo, Wistar rats were subjected to a biological model of metabolic syndrome, the rats were dosed with royal jelly and the blood pressure were measured every week. Significant differences (P&lt;0.05) were found in the concentration of amino acids Arg and His between three types of royal jelly; regarding amino acids associated with antihypertensive activity, no significant differences (P&gt;0.05) were found. The angiotensin converting enzyme inhibition values were less than 25%; however, the blood pressure in the groups of rats that received the royal jelly treatments was similar to the control group (P&gt;0.05). These results indicate that the diet with pollen or M. pruriens consumed by the bees does not affect the bioactive compounds responsible for the in vivo antihypertensive activity, and we found that the continuous consumption of royal jelly prevents the elevation in the blood pressure values.

Background:This study aimed to investigate the possible restorative effects of bone marrow-derived mesenchymalstem cells (BM-MSCs) along with royal jelly (RJ) on a rat model of polycystic ovary syndrome (PCOS). Materials and Methods:In this experimental study, 50 female Wistar rats (150-200 g) were randomly assignedto five groups: control, PCOS, PCOS+BM-MSCs, PCOS+RJ, and PCOS+BM-MSCs+RJ. PCOS was induced bysubcutaneous injection of testosterone enanthate (100 mg/kg). BM-MSCs were administered via tail vein every twoweeks. RJ was given orally (500 mg/kg/day) for 14 days. Two weeks post-treatment, blood samples were analyzed forinterleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX2), using ELISA. Ovarian tissues were examined histologically, and bone morphogenetic protein 15(BMP15) and growth differentiation factor 9 (GDF9) levels were measured by Western blot.Results:RJ and BM-MSCs improved abnormal follicle structure in PCOS rats. The mean serum levels of IL-6(P=0.016) and TNF-α (P<0.0001) were significantly reduced in the PCOS+RJ+BM-MSCs group compared to thePCOS rats. However, there was no statistically significant reduction in expression of VEGF (P=0.090) and COX-2(P=0.104). The expression levels of BMP15 and GDF9 proteins were significantly reduced in PCOS rats comparedto the control group (P<0.0001), while in the PCOS+RJ+BM-MSCs group, the expression of BMP15 (P<0.001) andGDF9 (P<0.0001) proteins increased compared to the PCOS group.Conclusion:RJ and BM-MSCs may restore ovarian function by regulating inflammation, angiogenesis, and oocytequality.

Objective Royal jelly is a honey bee secretion with beneficial effects on the nervous system. The present study aims to investigate the effects of royal jelly in reducing seizure and anxiety-like behaviors in Syrian rats. Methods This is an experimental study. In the seizure model, 25 male white Syrian rats were randomly divided into five groups: Control, royal jelly 100 mg/kg, royal jelly 200 mg/kg, royal jelly 400 mg/kg, and phenobarbital. After 30 minutes, strychnine was injected to induce seizure in animals. The time of seizure onset, seizure duration, and mortality rate in animals were recorded. In the anxiety model, 35 male white Syrian rats were randomly divided into five groups: Control, royal jelly 50 mg/kg, royal jelly 100 mg/kg, royal jelly 200 mg/kg, and diazepam. Anxiety-like behaviors were examined by using the elevated plus maze (EPM) test. Data analysis was performed using one-way ANOVA, and P&lt;0.05 was statistically significant. Results Royal jelly at doses of 200 and 400 mg/kg delayed the time of seizure onset and reduced the seizure duration compared to the control group (P&lt;0.05). The mortality rate was also reduced after using different doses of royal jelly compared to the control group (P&lt;0.05). Moreover, royal jelly at doses of 50 and 100 mg/kg increased the time spent in the open arms of the EPM platform and the number of entries to the open arms compared to the control group (P&lt;0.05). Conclusion Administration of royal jelly can reduce strychnine-induced seizure and modulate anxiety-like behaviors in rats.

To compare the protein complement of royal jelly (RJ) from high RJ producing honeybees ( Apis mellifera L.), a strain of A. mellifera artificially selected for increased RJ production from Italian honeybees in China for more than two decades was compared to those of native Italian honeybees ( A. mellifera L.) and Carnica honeybees ( A. mellifera C.); the protein in RJ from these three strains of honeybees was partially identified by using a combination of two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS), and a protein engine identification tool applied to the honeybee genome. The results showed that 152, 157, and 137 proteins were detected in the three species of RJ; among which 57, 57, 51 high abundant proteins ere identified, respectively. Most identifited spots, 45, 45, 41, were assigned to major royal jelly proteins (MRJPs). Remarkable differences were found in the heterogeneity of the MRJPs, in particular, MRJP3. Also, 3-glucose oxidase, 1-peroxiredoxin (PRDX), and 1-glutathione S-transferase (GST) S1 were identified in three RJ samples. Furthermore, during the determination of the peptides mass fingerprinting (PMF) of each spot, for the first time, PRDX and GST S1 proteins have been identified in RJ. Thus, the results suggest that the protein complement of high RJ producing honeybees is not different compared to native Italian honeybees, while a difference remains between Carnica honeybees.

Royal jelly ameliorates diet-induced obesity and glucose intolerance by promoting brown adipose tissue thermogenesis in mice

Oral diseases affect a very large number of people, and the applied pharmacological methods of treatment and/or prevention have serious side effects. Therefore, it is necessary to search for new, safer methods of treatment. Natural bee products, such as honey, royal jelly, and bee venom, can be a promising alternative in the treatment of oral cavity bacterial infections. Thus, we performed an extensive literature search to find and summarize all articles about the antibacterial activity of honey, royal jelly, and bee venom. Our analysis showed that these bee products have strong activity against the bacterial strains causing caries, periodontitis, gingivitis, pharyngitis, recurrent aphthous ulcers, supragingival, and subgingival plaque. An analysis of average MIC values showed that honey and royal jelly have the highest antimicrobial activity against Porphyromonas gingivalis and Fusobacterium nucleatum. In turn, bee venom has an antibacterial effect against Streptococcus mutans. Streptococcus sobrinus and Streptoccus pyogenes were the most resistant species to different types of honey, and royal jelly, respectively. Moreover, these products are safer in comparison to the chemical compounds used in the treatment of oral cavity bacterial infections. Since the antimicrobial activity of bee products depends on their chemical composition, more research is needed to standardize the composition of these compounds before they could be used in the treatment of oral cavity bacterial infections.

Carbendazim is usually used to control the Sclerotinia sclerotiorum of rapes during the flowering period. This paper presents a study on transfer assessment of carbendazim residues from rape flowers to apicultural products. In the field trials, the rapes were sprayed with carbendazim on standard dosage. Bees produced apicultural products (bee pollen, honey, and royal jelly) from sprayed rapes. Apicultural products were collected on a regular basis. Carbendazim residues were extracted from bee pollen, honey, and royal jelly, respectively. HPLC/ESI-MS/MS method was developed and partially validated to identify and quantify carbendazim residues. The limits of quantification in pollen, honey, and royal jelly were 0.01 mg/kg. Mathematical curve fitting was carried out on the basis of transfer assessment of carbendazim residues from rape flowers to apicultural products. The respective carbendazim residues were 1.10 ± 0.03 mg/kg in pollen on 18th day, 0.032 ± 0.001 mg/kg in honey on 24th day, and 0.077 ± 0.002 mg/kg in royal jelly on 22nd day. Transfer assessment and mathematical curve fitting of carbendazim residues from rape flowers to apicultural products show carbendazim diminished over spraying time. The gap of carbendazim residues between pollen and honey is decreased with time. The carbendazim residues in pollen are 10 times higher than that of honey and jelly.

It has been well-known that fatty acids occurring in the royal jelly of honeybees are effective towards autonomic imbalance, perimenopausal symptoms, osteoporosis, and other conditions. These pharmacological effects of royal jelly similar to those caused by the hormone estrogen are thought to appear due to the interaction of the fatty acids of royal jelly with an estrogen receptor inside the human body. Although the structure of several major fatty acids present in royal jelly has been determined experimentally, no direct evidence of the interaction of these fatty acids with the estrogen receptor have been reported yet. In this study, we therefore give an insight into the interaction of fatty acids with the human estrogen receptor β by quantum mechanical (QM), ONIOM, and molecular dynamics (MD) methods using a model active site.

MiRNAs are small non-coding RNA molecules that play important regulatory roles in diverse biological processes. Royal jelly, a milky-white substance produced by nurse honeybees (Apis mellifera), is the primary food of queen bees and plays a crucial role in their development. However, little is known about the microRNA (miRNAs) content of royal jelly and their potential functions. In this study, we isolated extracellular vesicles from the royal jelly of 36 samples through sequential centrifugation and targeted nanofiltration and performed high-throughput sequencing to identify and quantify the miRNA content of honeybee royal jelly extracellular vesicles (RJEVs). We found a total of 29 known mature miRNAs and 17 novel miRNAs. Through bioinformatic analysis, we identified several potential target genes of the miRNAs present in royal jelly, including those involved in developmental processes and cell differentiation. To investigate the potential roles of RJEVs in cell viability, RJEVs were supplemented to apoptotic porcine kidney fibroblasts induced by ethanol 6% exposure for 30min. TUNEL assay showed a significant reduction in the apoptosis percentage after RJEV supplementation when compared with the non-supplemented control group. Moreover, the wound healing assay performed on the apoptotic cells showed a rapid healing capacity of RJEV-supplemented cells compared to the control group. We observed a significant reduction in the expression of the miRNA target genes such as FAM131B, ZEB1, COL5A1, TRIB2, YBX3, MAP2, CTNNA1, and ADAMTS9 suggesting that RJEVs may regulate the target gene expression associated with cellular motility and cell viability. Moreover, RJEVs reduced the expression of apoptotic genes (CASP3, TP53, BAX, and BAK), while significantly increasing the expression of anti-apoptotic genes (BCL2 and BCL-XL). Our findings provide the first comprehensive analysis of the miRNA content of RJEVs and suggest a potential role for these vesicles in the regulation of gene expression and cell survival as well as augmenting cell resurrection or anastasis.

The genetic selection of a high royal jelly (RJ)-producing strain of bees (RJBs) from Italian bees (ITBs) has been conducted for nearly four decades in China since the 1980s. RJBs are the most important producers of RJ in the world and produce > 90% of the total output with an annual market value of > $40 million. With technological advancements in proteomics, the mechanism underpinning the high RJ production by RJBs has been explored to new depths in the last decades. Here, we give an overview that the mechanism driving the enhanced performance of RJ secretion by RJBs. First, the selection of RJBs, high-efficiency technology for RJ production, and advances in genetic characterization of RJBs are reviewed. Then, proteome and phosphoproteome characterization that decipher the augmented RJ production using honeybee organs and tissues are summarized. This may be potentially useful in gaining a complete mechanistic insight into the high performance of RJ yields in honeybees, and expands understanding of the honeybee biology.