Amino acid composition of royal jelly harvested at different times after larval transfer

Effects of Sucrose Feeding on the Quality of Royal Jelly Produced by Honeybee Apis mellifera L

Royal jelly (RJ) is a highly nutritious secretion of the honeybees' hypopharyngeal glands (HPGs). During RJ production, colonies are occasionally subjected to manual interventions, such as sucrose feeding for energy supplementation. This study aimed to assess the impact of sucrose feeding on the composition of RJ. The results indicated that RJ obtained from sucrose-fed colonies exhibited significantly higher levels of fructose, alanine, glycine, tyrosine, valine, and isoleucine compared to the honey-fed group. However, no significant differences were observed in terms of moisture content, crude protein, 10-HDA, glucose, sucrose, minerals, or other amino acids within the RJ samples. Moreover, sucrose feeding did not have a significant effect on midgut sucrase activity, HPGs development, or the expression levels of MRJP1 and MRJP3 in nurse bees. Unsealed stored food samples from sucrose-fed bee colonies demonstrated significantly higher sucrose levels compared to sealed combs and natural honey. Additionally, natural honey exhibited higher moisture and Ca levels, as well as lower levels of Zn and Cu, in comparison to honey collected from bee colonies fed sucrose solutions. Based on these findings, we conclude that sucrose feeding has only a minor impact on the major components of RJ.

Molecular Insights into Royal Jelly Anti-Inflammatory Properties and Related Diseases

Royal jelly (RJ), a highly nutritious natural product, has gained recognition for its remarkable health-promoting properties, leading to its widespread use in the pharmaceutical, food, and cosmetic industries. Extensive investigations have revealed that RJ possesses a broad spectrum of therapeutic effects, including anti-inflammatory, antioxidant, antitumor, anti-aging, and antibacterial activities. Distinctive among bee products, RJ exhibits a significantly higher water and relatively lower sugar content. It is characterized by its substantial protein content, making it a valuable source of this essential macronutrient. Moreover, RJ contains a diverse array of bioactive substances, such as lipids, phenolic compounds, flavonoids, organic acids, minerals, vitamins, enzymes, and hormones. This review aims to provide an overview of current research on the bioactive components present in RJ and their associated health-promoting qualities. According to existing literature, these bioactive substances hold great potential as alternative approaches to enhancing human health. Notably, this review emphasizes the anti-inflammatory properties of RJ, particularly in relation to inflammatory diseases, such as multiple sclerosis (MS), rheumatoid arthritis (RA), and inflammatory bowel diseases (IBD). Furthermore, we delve into the antitumor and antioxidant activities of RJ, aiming to deepen our understanding of its biological functions. By shedding light on the multifaceted benefits of RJ, this review seeks to encourage its utilization and inspire further investigation in this field.

Mechanistic Insight into Royal Protein Inhibiting the Gram-Positive Bacteria

Royal jelly (RJ), a natural honeybee product, has a wide range of antibacterial activities. N-glycosylated major royal jelly protein 2 (N-MRJP2), purified from RJ, can inhibit the growth of Paenibacillus larvae (P. larvae, Gram-positive), a contagious etiological agent of the American foulbrood disease of honeybees. However, the inhibitory mechanism is largely unknown. Antibacterial assay and membrane proteome were conducted to investigate the inhibition capacity of RJ from different instar larvae and P. larvae treated by N-MRJP2, respectively. The similar antibacterial efficiency of RJ from different larval instar indicates that RJ is vital for the adaptive immune defense of small larvae. The killing of P. larvae by N-MRJP2 is achieved by disturbing the cell wall biosynthesis, increasing the permeability of cell membrane, hindering aerobic respiration, restraining cell division and inducing cell death. This demonstrates that RJ is critical for the passive immunity of immature larvae and N-MRJP2 can be used as natural antibiotic substance to resist P. larvae, even for other gram-positive bacteria. This constitutes solid evidence that RJ and N-MRJP2 have potentials as novel antibacterial agents.

Metabolic profiling unravels the effects of enhanced output and harvesting time on royal jelly quality

Royal jelly (RJ), a natural secretion of nurse bees, is a functional food with health-promoting properties. To investigate RJ quality changes with enhanced output and harvesting time, we compared metabolic profiles of RJ harvested at 24 h, 48 h, and 72 h after larval grafting into queen cells from Italian bees (ITBs) and high RJ-producing bees (RJBs) selected from ITBs. A total of 77 high-abundance compounds were identified with reverse-phase liquid chromatography- and hydrophilic interaction liquid chromatography-high-resolution mass spectrometry. Metabolite abundance, water content, and antibacterial activity were found largely unchanged between both bee strains, indicating that a similar RJ quality was achieved. Notably, the observed 10-hydroxy-2-decenoic acid content in RJBs (1.98%) and ITBs (2.41%) meet the standard for premium RJ in China. RJ harvested at 48 h and 72 h had similar metabolic profiles, indicating little influence of the two harvesting times on RJ quality. The harvesting at 24 h could lead to a higher RJ quality with higher abundance levels of many bioactive compounds and lower water content. Our data based mainly on RJ metabolic composition constitute evidence for mass production of high-quality RJ.

Royal Jelly and Its Components Promote Healthy Aging and Longevity: From Animal Models to Humans

Aging is a natural phenomenon that occurs in all living organisms. In humans, aging is associated with lowered overall functioning and increased mortality out of the risk for various age-related diseases. Hence, researchers are pushed to find effective natural interventions that can promote healthy aging and extend lifespan. Royal jelly (RJ) is a natural product that is fed to bee queens throughout their entire life. Thanks to RJ, bee queens enjoy an excellent reproductive function and lengthened lifespan compared with bee workers, despite the fact that they have the same genome. This review aimed to investigate the effect of RJ and/or its components on lifespan/healthspan in various species by evaluating the most relevant studies. Moreover, we briefly discussed the positive effects of RJ on health maintenance and age-related disorders in humans. Whenever possible, we explored the metabolic, molecular, and cellular mechanisms through which RJ can modulate age-related mechanisms to extend lifespan. RJ and its ingredients—proteins and their derivatives e.g., royalactin; lipids e.g., 10-hydroxydecenoic acid; and vitamins e.g., pantothenic acid—improved healthspan and extended lifespan in worker honeybees Apis mellifera, Drosophila Melanogaster flies, Gryllus bimaculatus crickets, silkworms, Caenorhabditis elegans nematodes, and mice. The longevity effect was attained via various mechanisms: downregulation of insulin-like growth factors and targeting of rapamycin, upregulation of the epidermal growth factor signaling, dietary restriction, and enhancement of antioxidative capacity. RJ and its protein and lipid ingredients have the potential to extend lifespan in various creatures and prevent senescence of human tissues in cell cultures. These findings pave the way to inventing specific RJ anti-aging drugs. However, much work is needed to understand the effect of RJ interactions with microbiome, diet, activity level, gender, and other genetic variation factors that affect healthspan and longevity.