Royal Jelly Proteins Research Articles

The Ontogeny and Dietary Differences in Queen and Worker Castes of Honey Bee (Apis cerana cerana)

The honey bee Apis cerana cerana (A. c. cerana), a subspecies of Apis cerana, is endemic in China and possesses a valuable ecological niche. Understanding the ways to protect this honey bee’s populations is crucial, but this topic has been understudied. For the efficient utilization of beekeeping and pollination, there is a need to explore its biology and management practices. In light of this, the current study was carried out to investigate the ontogeny and dietary differences in the queen and worker castes of the A. c. cerana honey bee. This article presents, supplemented by reference images, a detailed description of the life history of A. c. cerana queens and workers. Additionally, this study investigated the nutritional differences between royal jelly (RJ) and worker jelly (WJ) at various larval ages. The contents of the moisture, crude protein, and amino acids in RJ and WJ were determined via freeze drying, Kjeldahl nitrogen determination, and ultra-high performance liquid chromatography. The results highlight significant variations in the moisture content, crude protein concentration, and amino acid concentration between RJ and WJ. The results offer theoretical support for ex situ artificial rearing practices of A. c. cerana.

SIRT3, a New Hope in Liver Diseases from Pathogenic Mechanisms to Therapeutic Strategies.

The liver, the largest internal organ in the human body, regulates multiple reactions and processes, including detoxification, regeneration, and immune defense. Liver diseases have emerged as a significant global public health issue. Numerous studies have indicated that the mitochondrial deacetylase SIRT3 has played various roles in the pathogenesis and pathological progression of liver diseases. Objectives: This review aims to explore the advances in the study of SIRT3 and liver disease and review possible mechanisms. Natural and chemical activators of SIRT3 are also discussed. The role of SIRT3 in the pathogenic mechanisms and therapeutic strategies of liver disease is summarized by reviewing Pubmed. SIRT3 alleviates liver diseases by regulating fatty acid metabolism, mitochondrial function, and immune-inflammatory response. Meanwhile, Withaferin A, lipoic acid, major royal jelly proteins, and berberine can activate SIRT3 or upregulate its expression, thereby alleviating liver damage. SIRT3 can effectively slow down the progression of liver disease and protect the liver from further damage. The use of SIRT3 as a pharmacological target for the treatment of liver disease is a potential therapeutic approach.

Effects of royal jelly and its extracts on endometrial receptivity and MCF-7 cell growth in rats with thin endometrium

Royal jelly (RJ) is rich in various nutrients, including proteins and amino acids. RJ consumption improves sexual and urinary function in postmenopausal women, possibly owing to its hormone-like effects. Currently, hormone regulation and assisted reproductive technologies are widely used to treat thin endometria; however, high doses of these drugs can add to liver burden. In this study, RJ proteins and fatty acids were isolated, and their therapeutic effects on thin endometria were investigated in vivo and in vitro to verify their hormone-like regulatory effects. The results showed that RJ and its extracts could regulate endometrial receptivity-related factor expression levels in rats with a thin endometrium, accelerate MCF-7 cell apoptosis, and increase estrogen receptor expression in MCF-7 cells wherein. The estrogen-like effects of RJ and the fatty acids may be the main contributors. RJ may be a potential natural hormone replacement therapy.

Identification of low-abundance proteins in the royal jelly using the Osborne classification method

Royal jelly (RJ) is recognized as healthy food, with a high content of proteins. These proteins play important roles in honeybee caste and human health, but the proteomic analysis of low-abundance proteins in RJ has long been a challenge. Herein, we used the Osborne classification method to separate the RJ proteins of Xinjiang black bees into various fractions. The globulin, ethanol-soluble protein, and glutelin fractions were further separated by SDS-PAGE, and proteomic analysis was carried out by LC-MS/MS and searched against the UniProt database. A total of 23 secretory proteins were identified by proteomic analysis, in which 7 proteins were identified for the first time in RJ. The Osborne classification method combining one-dimensional gel electrophoresis-based proteomic analysis allows the identification of low-abundance proteins in the RJ and greatly extends the knowledge about the components and functions of RJ proteins. The raw data are available via ProteomeXchange with the identifier PXD023315. SignificanceThis study makes an important contribution to the research of the components and functions of low-abundance royal jelly proteins for the following reasons:1.The Osborne method was applied to fractionize the royal jelly proteins, which benefits the identification of low-abundance proteins.2.23 secretory proteins were identified from the globulins, the ethanol-soluble proteins, and the glutelins of the RJ, and there were 7 proteins identified for the first time in royal jelly.3.This study extends the knowledge about the components and functions of royal jelly proteins.

Exploring the impact of protein diets on the honey bee (Apis mellifera L): a study on intestinal tissue health and royal jelly protein level

The growth and development of a honey bee colony fundamentally rely on proper nutrition, leading beekeepers to nourish their hives to maintain the health and productivity of their colonies. Nevertheless, the substances utilized in honey bee nutrition vary widely, necessitating thorough research to evaluate their effects on the performance and health of honey bees. Herein, the supplemental diets commonly used by beekeepers for feeding bee colonies including soybean (Glycine max), maize pollen grains (Zea mays L), and a mixture of soybean and pollen grains, in addition to sugar solution as control group are evaluated. This study was conducted on both intestinal tissues as the main place of digestion and absorption and royal jelly (RJ) proteins as a final product that reflects physiological reactions within the insect’s body. Soybean has been observed to have detrimental effects on both the health of the intestinal tissue, causing atrophy of the epithelial cells and weakening of the stomach muscles. Additionally, a decrease in the secretory vesicles (SV) and the gelatinous layer (GL) within the intestine was noted. However, when honey bee colonies were fed on pollen, it helped maintain the molecular balance and high molecular weight proteins in RJ. Bee pollen diet also resulted in an increased production of SV. Conversely, feeding honey bees a mixture of soybean and pollen had catastrophic effects on both the intestinal tissue and RJ proteins. It also led to coagulation in the peritrophic membrane (PMb), which is crucial for protecting the intestinal walls and performing other physiological functions. This, in turn, impacted the absorption of proteins, the levels of SV, and GL. Consequently, it is suggested to incorporate bee pollen as a dietary supplement in the feeding plan of honey bees.

Consuming royal jelly alters several phenotypes associated with overwintering dormancy in mosquitoes.

Females of the Northern house mosquito, Culex pipiens, enter an overwintering dormancy, or diapause, in response to short day lengths and low environmental temperatures that is characterized by small egg follicles and high starvation resistance. During diapause, Culex pipiens Major Royal Jelly Protein 1 ortholog (CpMRJP1) is upregulated in females of Cx. pipiens. This protein is highly abundant in royal jelly, a substance produced by honey bees (Apis mellifera), that is fed to future queens throughout larval development and induces the queen phenotype (e.g., high reproductive activity and longer lifespan). However, the role of CpMRJP1 in Cx. pipiens is unknown. We first conducted a phylogenetic analysis to determine how the sequence of CpMRJP1 compares with other species. We then investigated how supplementing the diets of both diapausing and nondiapausing females of Cx. pipiens with royal jelly affects egg follicle length, fat content, protein content, starvation resistance, and metabolic profile. We found that feeding royal jelly to females reared in long-day, diapause-averting conditions significantly reduced the egg follicle lengths and switched their metabolic profiles to be similar to diapausing females. In contrast, feeding royal jelly to females reared in short-day, diapause-inducing conditions significantly reduced lifespan and switched their metabolic profile to be similar nondiapausing mosquitoes. Moreover, RNAi directed against CpMRJPI significantly increased egg follicle length of short-day reared females, suggesting that these females averted diapause. Taken together, our data show that consuming royal jelly reverses several key seasonal phenotypes of Cx. pipiens and that these responses are likely mediated in part by CpMRJP1.

Royal Jelly: Biological Action and Health Benefits.

Royal jelly (RJ) is a highly nutritious natural product with great potential for use in medicine, cosmetics, and as a health-promoting food. This bee product is a mixture of important compounds, such as proteins, vitamins, lipids, minerals, hormones, neurotransmitters, flavonoids, and polyphenols, that underlie the remarkable biological and therapeutic activities of RJ. Various bioactive molecules like 10-hydroxy-2-decenoic acid (10-HDA), antibacterial protein, apisin, the major royal jelly proteins, and specific peptides such as apisimin, royalisin, royalactin, apidaecin, defensin-1, and jelleins are characteristic ingredients of RJ. RJ shows numerous physiological and pharmacological properties, including vasodilatory, hypotensive, antihypercholesterolaemic, antidiabetic, immunomodulatory, anti-inflammatory, antioxidant, anti-aging, neuroprotective, antimicrobial, estrogenic, anti-allergic, anti-osteoporotic, and anti-tumor effects. Moreover, RJ may reduce menopause symptoms and improve the health of the reproductive system, liver, and kidneys, and promote wound healing. This article provides an overview of the molecular mechanisms underlying the beneficial effects of RJ in various diseases, aging, and aging-related complications, with special emphasis on the bioactive components of RJ and their health-promoting properties. The data presented should be an incentive for future clinical studies that hopefully will advance our knowledge about the therapeutic potential of RJ and facilitate the development of novel RJ-based therapeutic opportunities for improving human health and well-being.

Antioxidant and Anti-Inflammatory Properties of Hydrolyzed Royal Jelly Peptide in Human Dermal Fibroblasts: Implications for Skin Health and Care Applications.

Hydrolyzed royal jelly peptide (RJP) has garnered attention for its health-promoting functions. However, the potential applications of RJP in skincare have not been fully explored. In this study, we prepared RJP through the enzymatic hydrolysis of royal jelly protein with trypsin and investigated its antioxidant and anti-inflammatory properties on primary human dermal fibroblasts (HDFs). Our results demonstrate that RJP effectively inhibits oxidative damage induced by H2O2 and lipid peroxidation triggered by AAPH and t-BuOOH in HDFs. This effect may be attributed to the ability of RJP to enhance the level of glutathione and the activities of catalase and glutathione peroxidase 4, as well as its excellent iron chelating capacity. Furthermore, RJP modulates the NLRP3 inflammasome-mediated inflammatory response in HDFs, suppressing the mRNA expressions of NLRP3 and IL-1β in the primer stage induced by LPS and the release of mature IL-1β induced by ATP, monosodium urate, or nigericin in the activation stage. RJP also represses the expressions of COX2 and iNOS induced by LPS. Finally, we reveal that RJP exhibits superior antioxidant and anti-inflammatory properties over unhydrolyzed royal jelly protein. These findings suggest that RJP exerts protective effects on skin cells through antioxidative and anti-inflammatory mechanisms, indicating its promise for potential therapeutic avenues for managing oxidative stress and inflammation-related skin disorders.

Hive Products: Composition, Pharmacological Properties, and Therapeutic Applications.

Beekeeping provides products with nutraceutical and pharmaceutical characteristics. These products are characterized by abundance of bioactive compounds. For different reasons, honey, royal jelly, propolis, venom, and pollen are beneficial to humans and animals and could be used as therapeutics. The pharmacological action of these products is related to many of their constituents. The main bioactive components of honey include oligosaccharides, methylglyoxal, royal jelly proteins (MRJPs), and phenolics compounds. Royal jelly contains jelleins, royalisin peptides, MRJPs, and derivatives of hydroxy-decenoic acid, particularly 10-hydroxy-2-decenoic acid (10-HDA), which possess antibacterial, anti-inflammatory, immunomodulatory, neuromodulatory, metabolic syndrome-preventing, and anti-aging properties. Propolis has a plethora of activities that are referable to compounds such as caffeic acid phenethyl ester. Peptides found in bee venom include phospholipase A2, apamin, and melittin. In addition to being vitamin-rich, bee pollen also includes unsaturated fatty acids, sterols, and phenolics compounds that express antiatherosclerotic, antidiabetic, and anti-inflammatory properties. Therefore, the constituents of hive products are particular and different. All of these constituents have been investigated for their properties in numerous research studies. This review aims to provide a thorough screening of the bioactive chemicals found in honeybee products and their beneficial biological effects. The manuscript may provide impetus to the branch of unconventional medicine that goes by the name of apitherapy.

Exploring the effect of high-pressure processing conditions on the deaggregation of natural major royal jelly proteins (MRJPs) fibrillar aggregates

High pressure processing is a safe and green novel non-thermal processing technique for modulating food protein aggregation behavior. However, the systematic relationship between high pressure processing conditions and protein deaggregation has not been sufficiently investigated. Major royal jelly proteins, which are naturally highly fibrillar aggregates, and it was found that the pressure level and exposure time could significantly promote protein deaggregation. The 100–200 MPa treatment favoured the deaggregation of proteins with a significant decrease in the sulfhydryl group content. Contrarily, at higher pressure levels (>400 MPa), the exposure time promoted the formation of disordered agglomerates. Notably, the inter-conversion of α-helix and β-strands in major royal jelly proteins after high pressure processing eliminates the solvent-free cavities inside the aggregates, which exerts a 'collapsing' effect on the fibrillar aggregates. Furthermore, the first machine learning model of the high pressure processing conditions and the protein deaggregation behaviour was developed, which provided digital guidance for protein aggregation regulation.

The characterization of Apis cerana and Apis mellifera mrjp2 gene in Indonesia and the phylogeny relationship with mrjp family genes

The major royal jelly protein 2 (mrjp2) gene is one of the molecular markers that can discriminate between Apis cerana Fabricius and A. mellifera Linnaeus. Due to the lack of mrjp2 gene sequences registered in GenBank for Indonesian A. cerana and A. mellifera, DNA characterization and bioinformatics analysis were needed. This research aimed to characterize the exon-intron organization of mrjp2 genes for both Indonesian bee species and analyze the phylogenetic relationship with other mrjp family genes. DNA samples of Apis cerana and A. mellifera, collected from Bogor, were amplified using MF-MR primer at annealing temperatures of 47 oC and 50 oC, respectively. The length of A. cerana and A. mellifera DNA sequences were 579 and 597 bp, respectively. The DNA sequences of both species were comprised of partial exons 1, introns 1, exons 2, introns 2, and partial exon 3. The number of putative amino acids of A. cerana and A. mellifera mrjp2 genes were 111 and 123, respectively. We confirmed that the partial MRJP2 putative amino acids of both honey bees belong to the MRJP family and contained the peptide signal in the 14 first amino acid sites. Nucleotide variation of the mrjp2 gene in A. cerana was higher than A. mellifera. Phylogenetic tree construction showed that A. cerana and A. mellifera form a monophyletic clade with the A. mellifera mrjp7 gene and another mrjp family gene clustered as reported in a previous study.

Genome-wide identification of yellow gene family in Hermetia illucens and functional analysis of yellow-y by CRISPR/Cas9.

The yellow gene family plays a crucial role in insect pigmentation. It has potential for use as a visible marker gene in genetic manipulation and transgenic engineering in several model and non-model insects. Sadly, yellow genes have rarely been identified in Stratiomyidae species and the functions of yellow genes are relatively unknown. In the present study, we first manually annotated and curated 10 yellow genes in the black soldier fly (BSF), Hermetia illucens (Stratiomyidae). Then, the conserved amino acids in the major royal jelly proteins (MRJPs) domain, structural architecture and phylogenetic relationship of yellow genes in BSF were analyzed. We found that the BSF yellow-y, yellow-c and yellow-f genes are expressed at all developmental stages, especially in the prepupal stage. Using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein9 (Cas9) system, we successfully disrupted yellow-y, yellow-c and yellow-f in the BSF. Consequently, the mutation of yellow-y clearly resulted in a pale-yellow body color in prepupae, pupae and adults, instead of the typical black body color of the wild type. However, the mutation of yellow-c or yellow-f genes did not result in any change in color of the insects, when compared with the wild type. Our study indicates that the BSF yellow-y gene plays a role in body pigmentation, providing an optimal marker gene for the genetic manipulation of BSF.

Investigating the Protein-Based Therapeutic Relationship between Honey Protein SHP-60 and Bevacizumab on Angiogenesis: Exploring the Synergistic Effect through In Vitro and In Silico Analysis.

Honey is a natural product produced by honeybees, which has been used not only as food but also as a medicine by humans for thousands of years. In this study, 60 kDa protein was purified from Pakistani Sidr honey named as SHP-60 (Sidr Honey Protein-60), and its antioxidant potential and the effect of Bevacizumab with purified protein on in vitro angiogenesis using human umbilical vein endothelial cells (HUVEC) were investigated. We further validated the molecular protein-protein (SHP-60 with Bevacizumab) interactions through in silico analysis. It showed very promising antioxidant activity by reducing 2,2-diphenyl-1-picrylhydrazyl free radicals with a maximum of 83% inhibition at 50 μM and an IC50 of 26.45 μM statistically significant (**p < 0.01). Angiogenesis is considered a hallmark of cancer, and without it, the tumor cannot grow or metastasize. Bevacizumab, SHP-60, and both in combination were used to treat HUVEC, and the MTT assay was used to assess cell viability. To demonstrate in vitro angiogenesis, HUVEC was grown on Geltrex, and the formation of endotubes was examined using a tube formation assay. HUVEC viability was dose-dependently decreased by Bevacizumab, SHP-60, and both together. Bevacizumab and SHP-60 both inhibited angiogenesis in vitro, and their combination displayed levels of inhibition even higher than those of Bevacizumab alone. We investigated the protein-protein molecular docking interactions and molecular dynamics simulation analysis of MRJP3 (major royal jelly protein 3) similar to SHP-60 in molecular weight with both the heavy chain (HC) and light chain (LC) of Bevacizumab. We found significant interactions between the LC and MRJP3, indicating that ASN468, GLN470, and ASN473 of MRJP3 interact with SER156, SER159, and GLU161 of LC of Bevacizumab. The integration of experimental data and computational techniques is believed to improve the reliability of the findings and aid in future drug design.

Simultaneous PCR detection of Paenibacillus larvae targeting insertion sequence IS256 and Melissococcus plutonius targeting pMP1 plasmid from hive specimens

Paenibacillus larvae and Melissococcus plutonius represent the most threatening bacterial diseases of honeybee (Apis mellifera)—American and European foulbrood, respectively. For efficient control of those diseases, rapid and accurate detection of the pathogens is crucial. Therefore, we developed a novel multiplex PCR method simultaneously detecting both pathogens. To design and optimize multiplex PCR reaction, four strains of P. larvae representing four ERIC genotypes I–IV (strain DSM 7030—ERIC I, DSM 25430—ERIC II, LMG 16252—ERIC III, DSM 3615—ERIC IV) were selected. Those strains were fully sequenced using long-read sequencing (Sequel I, Pacific Biosciences). For P. larvae, the multicopy insertion sequence IS256 identified in all genotypes of P. larvae was selected to provide high sensitivity. M. plutonius was detected by plasmid pMP1 sequence and the virulence verified by following detection of ETX/MTX2 toxin responsible for pore formation in the cell membrane. As an internal control, a gene encoding for major royal jelly protein 1 specific for honeybees was selected. The method was validated on 36 clinical specimens collected from the colonies suffering from American and European foulbrood in the Czech Republic. Based on the results, sensitivity of PCR was calculated to 93.75% and specificity to 100% for P. larvae diagnosed from hive debris and 100% sensitivity and specificity for honeybee workers and larval scales as well as for diseased brood infected by M. plutonius.

Jelleine, a Family of Peptides Isolated from the Royal Jelly of the Honey Bees (Apis mellifera), as a Promising Prototype for New Medicines: A Narrative Review.

The jelleine family is a group of four peptides (jelleines I-IV) originally isolated from the royal jelly of honey bee (Apis mellifera), but later detected in some honey samples. These oligopeptides are composed of 8-9 amino acid residues, positively charged (+2 to +3 at pH 7.2), including 38-50% of hydrophobic residues and a carboxamide C-terminus. Jelleines, generated by processing of the C-terminal region of major royal jelly proteins 1 (MRJP-1), play an important biological role in royal jelly conservation as well as in protecting bee larvae from potential pathogens. Therefore, these molecules present numerous benefits for human health, including therapeutic purposes as shown in preclinical studies. In this review, we aimed to evaluate the biological effects of jelleines in addition to characterising their toxicities and stabilities. Jelleines I-III have promising antimicrobial activity and low toxicity (LD50 > 1000 mg/Kg). However, jelleine-IV has not shown relevant biological potential. Jelleine-I, but not the other analogues, also has antiparasitic, healing, and pro-coagulant activities in addition to indirectly modulating tumor cell growth and controlling the inflammatory process. Although it is sensitive to hydrolysis by proteases, the addition of halogens increases the chemical stability of these molecules. Thus, these results suggest that jelleines, especially jelleine-I, are a potential target for the development of new, effective and safe therapeutic molecules for clinical use.

Effect of digestion product of royal jelly protein on SGC-7901 gastric cancer cell

Royal jelly used for larvae and queens has many health-promoting properties such as spatial memory improvement, antibacterial activity and antioxidant capacity. However, the anticancer ability of the royal jelly is not unknown. In this study, effect of the royal jelly protein on SGC-7901 gastric cancer cell was investigated, and the key factors including the cell morphological, the colony formation, the proliferation, the cycle, and the expression of p53 and poly (ADP-ribose) polymerase-1 (PARP-1) proteins were analyzed. Result showed royal jelly protein was excellent in inhibiting the growth of SGC-7901gastric cancer cell. After treating with the digestion product of royal jelly protein (0.05 mg/mL～0.20 mg/mL), the morphological of gastric cancer cell significantly shrink, and both of density and quantity (1000～491) of gastric cancer cell significantly (p < 0.05) decreased. The proliferation of gastric cancer was strongest inhibited by 62.84 % of 0.20 mg/mL royal jelly protein. The expression of p53 and PARP-1 protein of gastric cancer cell was respectively enhanced (0.29～0.46) and reduced (0.51～0.42). Moreover, the higher content of royal jelly protein (0.05 mg/mL～ 0.2 mg/mL), the stronger inhibit ability of 45 SGC-7901 gastric cancer cell. In conclusion, royal jelly protein can be used as a potential food in adjunctive therapy for gastric cancer.

Proteome analysis of propolis deciphering the origin and function of its proteins

Propolis is a resinous honeybee product, rich in polyphenolic compounds and with high economic value. Although extensive studies regarding the chemical composition of different propolis extracts have been carried out, the propolis proteome remained unknown. The present study aimed at characterizing the proteome of two geographically-distinct propolis originating from Belgium and Iran. Propolis extracts were analyzed by sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE) followed by Matrix Assisted Laser Desorption Ionization – Time of Flight Mass Spectrometry (MALDI-TOF MS) and Liquid chromatography-electrospray ionization MS (LC-ESI-MS) analyses. Our comprehensive proteomic analysis led to the identification of honeybee venom and royal jelly proteins, and numerous plant-defense proteins in propolis, extending our understanding of the antimicrobial properties of this complex natural substance. The proteome of both propolis was mainly made up of proteins belonging to the poplar tree. Pathogenesis-related (PR) proteins, poplar PR-2 (β-1,3-glucanases) and PR-8 (acidic endochitinases) were found to be the major components of both propolis extracts, while the major bee venom allergen (Api m 1) and royal jelly proteins (MJRP 1, 2, 3 and 5) were identified in the propolis from Belgium. Overall, our proteome analyses revealed that propolis extracts from Belgium and Iran shared a core protein composition originating from the poplar proteome. The majority of identified proteins are involved in the plant defense against pathogens, most belonging to well-known pathogenesis-related families. Proteomics could thus represent a viable approach for origin authentication and allergen identification in poplar-type propolis.

Transcriptome analysis of Apis mellifera antennae reveals molecular divergence underlying the division of labour in worker bees.

The olfactory system plays a fundamental role in mediating insect behaviour. Worker bees exhibit an age-dependent division of labour, performing discrete sets of behaviours throughout their lifespan. The behavioural states of bees rely on their sense of the environment and chemical communication via their olfactory system, the antennae. However, the olfactory adaptation mechanism of worker bees during their behavioural development remains unclear. In this study, we conducted a comprehensive and quantitative analysis of antennal gene expression in the Apis mellifera of newly emerged workers, nurses, foragers and defenders using RNA-seq. We found that the antenna tissues of honey bees continued developing after transformation from newly emerged workers to adults. Additionally, we identified differentially expressed genes associated with bee development and division of labour. We validated that major royal jelly protein genes are highly and specifically expressed in nurse honey bee workers. Furthermore, we identified and validated significant alternative splicing events correlated with the development and division of labour. These findings provide a comprehensive transcriptome profile and a new perspective on the molecular mechanisms that may underlie the worker honey bee division of labour.

A new approach for the treatment of bleomycin-induced rat pulmonary injury by combined protein fraction of major royal jelly protein 2 and its isoform X1

Nowadays, royal jelly (RJ) has gained great interest as a functional food due to its valuable pharmacological effects. We investigated the therapeutic potency of combined protein fraction (PF50) of major RJ protein 2 and its isoform X1 on bleomycin (Bleo)-induced pulmonary injury in rats. Our study examined the impact of PF50 on pulmonary oxidative and inflammatory stress as well as smooth muscle alpha-actin (α-SMA). In addition, the predicted impacts of this PF on the activity of matrix metalloproteinase (MMP)− 8 and 15-prostaglandin dehydrogenase (15-PGDH) and the E-type prostanoid 2 (EP2) and IL-13 α2 subunit (IL13α2R) receptors, were evaluated using molecular docking. The results showed that PF50 reduced pulmonary inflammatory cells and their secreted pro-inflammatory mediators, including NF-κB, IKK, IL-4, IL-6, and NO. Additionally, the levels of IgE and mucin were diminished after treatment with PF50. Moreover, PF50 treatment improved pulmonary oxidative stress indices such as lipid peroxidation, GSH, SOD, and GPX. The histopathological findings, chest conventional X-ray, and immunohistochemistry of α-SMA confirmed the ameliorating effect of PF50. The docking outcomes reported the probable competitive inhibitory influence of PF50 on MMP-8 and a postulated blocking effect on EP2 and IL13α2R. Thus, PF50 could be a novel approach for treating pulmonary injuries.

Mandibular glands secrete 24-methylenecholesterol into honey bee (Apis mellifera) food jelly

Honey bee (Apis mellifera) workers feed their larvae with food jelly that is secreted by specialized glands in their heads – the hypopharyngeal and the mandibular glands. Food jelly contains all the nutrients the larvae need to develop into adult honey bees, including essential dietary sterols. The main sterol in food jelly, 24-methylenecholesterol (24MC), is pollen-derived and delivered in food jelly to the larvae in a complex with two proteins, major royal jelly protein 1 (MRJP1) and apisim. Whereas the proteins are synthesized in the hypopharyngeal glands, the sterol-secreting gland has not been identified. We here identified the mandibular glands as sterol-secreting gland for food jelly production by direct detection of the four main honey bee sterols (24MC, campesterol, β-sitosterol and isofucosterol). Furthermore, 24MC seems to be specifically enriched in the mandibular glands, thereby ensuring that food jelly contains the amounts of 24MC necessary for complex formation with MRJP1 and apisimin.