Potential protective effect of Trans-10-hydroxy-2-decenoic acid on the inflammation induced by Lipoteichoic acid

Royal jelly acid alleviates diet-induced hyperlipidemia through regulation of oxidative stress and tryptophan metabolism

Royal jelly acid is a unique unsaturated fatty acid isolated from royal jelly. Recently, royal jelly acid was proposed to have potential therapeutic effects on hyperlipidemia. However, its effect on hyperlipidemia and the underlying molecular mechanism remains unclear. Therefore, in this study, we analyzed the mechanism of anti-hyperlipidemia of royal jelly acid through animal experiments and plasma metabolomics in conjunction with human network pharmacology and molecular docking analyses. We found that royal jelly acid could significantly decrease the serum lipid levels, ameliorate hepatic pathological injury, and reduce the level of oxidative stress in the experimental rats. A total of 41 key metabolites and 10 hub targets played key roles in the exertion of anti-hyperlipidemic effects, including tumor necrosis factor (TNF), insulin (INS) and epidermal growth factor receptor (EGFR). A total of 24 pathways, including tryptophan, citrate cycle, and arachidonic acid metabolisms, were identified as the key pathways involved in royal jelly acid-alleviated hyperlipidemia. The present findings provide new insights into the pathogenesis, diagnosis, and treatment targets of hyperlipidemia as well as contribute to the development and utilization of royal jelly acid related products.

10-Hydroxy-2-decenoic acid attenuates nonalcoholic fatty liver disease by activating AMPK-α signaling pathway

Nonalcoholic fatty liver disease (NAFLD) originates from metabolic dysfunctions, is one of the most commonly encountered liver disorders worldwide, characterized by ectopic lipid deposition within hepatocytes, accompanied by hepatocellular injury and necroinflammation. Currently, NAFLD has very few treatment options. Purified from royal jelly, 10-hydroxy-2-decenoic acid (10-HDA) is the primary bioactive ingredient with a series of beneficial effects against various metabolic diseases. Herein, we investigated the effects of 10-HDA in methionine and choline deficiency (MCD) diet induced NAFLD model and free fatty acids (FFAs) induced lipid-laden hepatocyte model and explored the underlying mechanisms. In the mice fed with MCD diet, 10-HDA treatment significantly reduced hepatic steatosis, hepatocellular injury, apoptosis, inflammatory response and fibrosis. In vitro, 10-HDA treatment reduced lipid accumulation and apoptosis in hepatocytes induced by FFAs. Mechanistically, 10-HDA therapy restored AMPK-α phosphorylation, leading to the phosphorylation and inactivation acetyl-CoA carboxylase (ACC). Consequently, this increased the expression of carnitine palmitoyl transferase 1α(CPT1α), and peroxisome proliferators-activated receptors α (PPARα), and lowered the expression of cleavage forms of sterol regulatory element binding protein-1 (SREBP-1) and fatty acid synthetase (FASN). Furthermore, pretreating the cells with the AMPK-α inhibitor, compound C, greatly eliminated these beneficial effects of 10-HDA. Additionally, molecular docking analysis indicated that 10-HDA bound the domain of AMPK-α1 subunit. Based on these findings, 10-HDA suppresses hepatic lipogenesis via AMPK-α-dependent suppression of the ACC pathway, thus inhibiting hepatocellular injury, apoptosis, inflammatory response and fibrosis. 10-HDA may represent a promising candidate drug for the treatment of NAFLD.

Fatty Acids Derived from Royal Jelly Exert Anti-Inflammatory and Antibacterial Activities in the Treatment of Pseudomonas aeruginosa-Induced Acute Pneumonia

Pseudomonas aeruginosa, an opportunistic pathogen, commonly causes hospital-acquired pneumonia. Royal jelly fatty acids (RJFAs), a mixture of various fatty acids extracted from royal jelly, exhibit antibacterial and anti-inflammatory properties in treating many infectious diseases. Nevertheless, the therapeutic mechanisms of RJFAs in treatment of acute P. aeruginosa pulmonary infection are still unclear. Herein, we initially extracted the fatty acids from royal jelly and characterized their chemical constituents using headspace gas chromatography-mass spectrometry. Furthermore, we examined the antibacterial effect of RJFAs in vitro and explored its therapeutic effect and molecular mechanisms in treating acute P. aeruginosa pulmonary infection in vivo. The in vitro antibacterial studies revealed that RJFAs significantly inhibited P. aeruginosa growth. Moreover, the in vivo studies showed that the RJFAs effectively mitigated the lung damage and inflammation induced by P. aeruginosa through impairing neutrophil infiltration, reducing the bacterial load in lung and diminishing the production of proinflammatory cytokines, including tumor necrosis factor (TNF-α), interleukin (IL-1β), IL-6, and macrophage inflammatory protein-2 (MIP-2). In addition, the mice treated with RJFAs exhibited reduced phosphorylation of extracellular signal-regulated kinase (ERK), p38, c-Jun N-terminal kinase (JNK), c-Jun, and nuclear factor-kappa B (NF-κB) p65 in the lung tissues in comparison with that of the mice without drug treatment. These findings demonstrated that RJFAs exhibited significant antibacterial and anti-inflammatory effects in treating the P. aeruginosa-induced acute pneumonia, and the anti-inflammatory effects were exerted through suppressing the mitogen-activated protein kinase/activator protein-1 (MAPK/AP-1) pathway and NF-κB activation, suggesting a promising therapeutic potential of RJFAs against acute bacterial pneumonia.

Royal jelly a promising therapeutic intervention and functional food supplement: A systematic review

Royal jelly (RJ), a secretion produced by honeybees, has garnered significant interest for its potential as a therapeutic intervention and functional food supplement. This systematic review aims to synthesize current research on the health benefits, bioactive components, and mechanisms of action of RJ. Comprehensive literature searches were conducted across multiple databases, including PubMed, Scopus, and Web of Science, focusing on studies published from 2000 to 2024 (April). Findings indicate that RJ exhibits a wide range of pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial, and anti-aging effects. Beneficial biological properties of RJ might be due to the presence of flavonoids proteins, peptides, fatty acids. Both preclinical and clinical studies have reported that RJ improves the immune function such as wound healing, and also decreases the severity of chronic diseases including diabetes and cardiovascular disorders. The molecular mechanisms underlying these effects involve modulation of signalling pathways such as NF-κB, MAPK, and AMPK. Despite promising results, the review identifies several gaps in the current knowledge, including the need for standardized dosing regimens and long-term safety assessments. Furthermore, variations in RJ composition due to geographic and botanical factors necessitate more rigorous quality control measures. This review underscores the potential of RJ as a multifunctional therapeutic agent and highlights the necessity for further well designed studies to fully elucidate its health benefits and optimize its use as a functional food supplement.

10-hydroxy-2-decenoic acid alleviates lipopolysaccharide-induced intestinal mucosal injury through anti-inflammatory, antioxidant, and gut microbiota modulation activities in chickens

Introduction

This study aimed to investigated the effects of 10-hydroxy-2-decenoic acid (10-HDA) on the growth performance, intestinal barrier, inflammatory response, oxidative stress, and gut microbiota of chickens challenged with lipopolysaccharide (LPS).

Methods

A total of 240 one-day-old chickens were randomly assigned to five treatment groups: (1) control group (basal diet + saline); (2) LPS group (basal diet + LPS); (3) Chlortetracycline (CTC) group (basal diet containing 75 mg/kg CTC + LPS); (4) 0.1% 10-HDA group (basal diet containing 1 g/kg 10-HDA + LPS); and (5) 0.5% 10-HDA group (basal diet containing 5 g/kg 10-HDA + LPS). All chickens were injected intraperitoneally with 0.5 mg/kg body weight of either LPS or saline at 17, 19, and 21 days of age.

Results

The results showed that dietary 10-HDA supplementation attenuated the loss in growth performance caused by the LPS challenge (p < 0.05). 10-HDA effectively alleviated LPS-induced intestinal mucosal injury, as evidenced by reduced bleeding, decreased serum diamine oxidase levels (p < 0.05), and increased villus/crypt ratios of the jejunum and ileum (p < 0.05). Dietary treatment with 0.1% 10-HDA reduced the concentrations of inflammatory cytokines (TNF-α, IL-1β, IL-6; p < 0.05), and increased immunoglobulin (IgA, IgG) and antioxidant enzyme levels (CAT, GSH-px, T-SOD) in the serum of LPS-challenged chickens (p < 0.05). These effects were similar to those observed in the CTC group. Moreover, 0.1% 10-HDA treatment reversed the LPS-induced variations in the mRNA expression of genes related to inflammation, antioxidant capacity, and intestinal tight junctions (p < 0.05). 16S rRNA analysis revealed that 10-HDA supplementation increased the relative abundance of Faecalibacterium and Clostridia_UCG-014 (p < 0.05). Additionally, it decreased the abundance of Clostridia_vadinBB60_group, Eubacterium_nodatum_group, and UC5-1-2E3 (p < 0.05). These changes were correlated with reduced inflammation and improved antioxidant capacity in the LPS-challenged chickens.

Conclusion

Collectively, dietary 10-HDA supplementation alleviated LPS-induced intestinal mucosal injury and the loss of growth performance through anti-inflammatory, antioxidant, and gut microbiota modulation activities in chickens. Moreover, 0.1% 10-HDA supplementation had comparable or even better protection for LPS-challenged chickens than supplementation with antibiotics or 0.5% 10-HDA. 10-HDA has the potential to be used as an alternative to antibiotics in protecting the intestinal health and improving the performance of poultry.

Integration of Metabolomic and Transcriptomic Provides Insights into Anti-Inflammatory Response to trans-10-Hydroxy-2-decenoic Acid on LPS-Stimulated RAW 264.7 Cells

Trans-10-hydroxy-2-decenoic acid (10-HDA) is a unique fatty acid found in royal jelly that possesses potential health benefits such as anti-inflammatory. However, further research is needed to fully understand its mechanisms of action and therapeutic potential for inflammation-associated diseases. In this present study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and RNA-seq analyses were conducted to comprehensively analyze the in vitro anti-inflammatory effects of 10-HDA on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Our results demonstrated that 128 differentially expressed metabolites and 1721 differentially expressed genes were identified in the 10-HDA-treated groups compared to the LPS groups. Metabolites were significantly enriched in amino acid metabolism pathways, including methionine metabolism, glycine and serine metabolism, and tryptophan metabolism. The differentially expressed genes enrichment analysis indicated that antigen processing and presentation, NOD-like receptor signaling pathway, and arginine biosynthesis were enriched with the administration of 10-had. The correlation analysis revealed that glycerophospholipid metabolism and s-adenosylmethionine-dependent methylation processes might be involved in the response to the 10-HDA treatment. Overall, the findings from this study showed that 10-HDA might involve the modulation of certain signaling pathways involved in the inflammatory response, but further research is needed to determine the safety and efficacy as a therapeutic agent.

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.

Current Status of the Bioactive Properties of Royal Jelly: A Comprehensive Review with a Focus on Its Anticancer, Anti-Inflammatory, and Antioxidant Effects

Royal jelly (RJ) has been one of the most widely used natural products in alternative medicine for centuries. Being produced by both hypopharyngeal and mandibular glands, RJ exhibits an extraordinary complexity in terms of its composition, including proteins, lipids, carbohydrates, polyphenols, vitamins, and hormones. Due to its heterogeneous structure, RJ displays various functional roles for honeybees, including being involved in nutrition, learning, memory, and social behavior. Furthermore, a wide range of studies reported its therapeutic properties, including anticancer, anti-inflammatory, and antioxidant activities, to name a few. In this direction, there is a wide range of health-related problems for which the medical area specialists and researchers are continuously trying to find a cure, such as cancer, atherosclerosis, or infertility. For the mentioned diseases and more, it has been proven that RJ is a key player in finding a valuable treatment. In this review, the great impact of RJ as an alternative medicine agent is highlighted, with a focus on its anticancer, anti-inflammatory, and antioxidant activities. Moreover, we link it to its apitherapeutic potential by discussing its composition. Herein, we discuss a wide range of novel studies and present the latest research work.

10-Hydroxy-trans-2-decenoic Acid, a New Potential Feed Additive for Broiler Chickens to Improve Growth Performance

The purposes of this study were to explore the potential possibility of 10-hydroxy-trans-2-decenoic acid (10-HDA) use in feeding broiler chickens. A total of 216 healthy 1-day-old chicks were divided into 2 treatments at random (diets supplemented with 0 or 40 mg/kg 10-HDA, respectively) with 6 replicates of 18 birds each, and were then reared for 42 days. The results found that a diet supplemented with 10-HDA significantly increased average daily gain of broiler chickens in d 22~42 and d 0~42. Compared with the control group, dietary inclusion of 10-HDA markedly increased the serum concentrations of immunoglobulin (Ig) G at d 21, as well as IgM and interleukin (IL)-10 at d 42, while decreasing the levels of tumor necrosis factor (TNF)-α at d 21, as well as IL-6, TNF-α, and IL-1β at d 42. Furthermore, broiler chickens fed a diet with 10-HDA had a higher (p < 0.05) serum activity of superoxide dismutase at d 42. Additionally, serum malondialdehyde content also decreased notably at d 21 and d 42. These results made it clear that 10-HDA increased the growth performance of broiler chickens, possibly by enhancing immune function and antioxidant capacity.

Major royal jelly proteins alleviate non-alcoholic fatty liver disease in mice model by regulating disordered metabolic pathways

Nonalcoholic fatty liver disease (NAFLD), the major cause of global chronic hepatic injury, has obtained increasing attention while the current drug treatment still laid safety hazards. Major royal jelly proteins (MRJPs), the water-soluble proteins enriched in royal jelly (RJ), were applied to study its effects on improving NAFLD in the NAFLD mouse model. Herein, we demonstrated that intaking of 250-500 mg/kg/day MRJPs significantly decreased the rate of obesity, dyslipidemia, hepatic steatosis, and insulin resistance. Next, TOF to MRM ("TM") widely targeted metabolomics (untargeted metabolomics + widely targeted metabolomics) was further used to explore the potential mechanism, and we found that 500 mg/kg MRJPs alleviated lipid metabolism, oxidative stress, and inflammation mainly by regulating the metabolisms of alpha-linolenic acid, linoleic acid, arachidonic acid, and biosynthesis of unsaturated fatty acids. Moreover, by detecting multiple oxidative stress factors and inflammatory cytokines, we found that MRJPs indeed exerted antioxidant and anti-inflammatory effects. Together, we demonstrated that MRJPs could mediate the progress of NAFLD through the "multi-component-multi-target-multi-pathway" mechanism, which could be considered as an ideal functional food in alleviating NAFLD. PRACTICAL APPLICATIONS: Royal jelly (RJ) is a bee product with high nutritional value. Major royal jelly proteins (MRJPs) are water-soluble proteins in RJ. Our research showed that MRJPs significantly ameliorated NAFLD induced by a high-fat diet in mice, suggesting that MRJPs could be used as an active ingredient to help improve NAFLD, which was beneficial for the development of related functional foods and the economic value of RJ. Moreover, the metabolic pathways involved in the ameliorative effect of MRJPs were investigated, which provided new ideas for the prevention and treatment of NAFLD.

Synergistic anti-inflammatory effects of graphene oxide quantum dots and trans-10-hydroxy-2-decenoic acid on LPS-stimulated RAW 264.7 macrophage cells

Graphene oxide quantum dots (GOQDs) have attracted substantial attention in numerous fields due to their unique physicochemical properties. However, their nanotoxicity and potential for use in biomedicine still require further study. In this work, the effects of GOQD and trans- 10-hydroxy-2-decenoic acid (10-HDA) cotreatment on the immune function of macrophages (RAW264.7 cells) were investigated. In particular, LC/MS-based metabolomics was performed to evaluate the effects of GOQDs on the metabolism of LPS-stimulated macrophages. Herein, we fabricated GOQDs with good dispersibility and a uniform size distribution of approximately 7 nm using a polyimide-pyrolyzed carbon film as the working electrode, a high-voltage graphite electrode as the cathode, and H₂O₂ as the oxidant. The GOQDs entered the macrophages and emitted green fluorescence under UV irradiation. Cotreatment with GOQDs and 10-HDA induced RAW 264.7 cell proliferation. GOQDs promoted the anti-inflammatory effect of 10-HDA on LPS-stimulated RAW264.7 cells and attenuated the secretion of TNF-α, IL-6, and IL-1β. The metabolites in RAW264.7 cells treated with GOQDs were significantly different from those in RAW264.7 cells treated with LPS. The enrichment analysis showed that treatment with GOQDs interfered with amino acid metabolism, and lipid metabolism. Our results demonstrate the role of GOQDs in macrophages and provide a basis for their further application in biomedical fields.

Anti-Biofilm and Anti-Hemolysis Activities of 10-Hydroxy-2-decenoic Acid against Staphylococcus aureus

Persistent infections caused by Staphylococcus aureus biofilms pose a major threat to global public health. 10-Hydroxy-2-decenoic acid (10-HDA), a main fatty acid in royal jelly, has been shown to possess various biological activities. The purpose of this study was to explore the effects of 10-HDA on the biofilms and virulence of S. aureus and its potential molecular mechanism. Quantitative crystal violet staining indicated that 10-HDA significantly reduced the biofilm biomass at sub-minimum inhibitory concentration (MIC) levels (1/32MIC to 1/2MIC). Scanning electron microscope (SEM) observations demonstrated that 10-HDA inhibited the secretion of extracellular polymeric substances, decreased bacterial adhesion and aggregation, and disrupted biofilm architecture. Moreover, 10-HDA could significantly decrease the biofilm viability and effectively eradicated the mature biofilms. It was also found that the hemolytic activity of S. aureus was significantly inhibited by 10-HDA. qRT-PCR analyses revealed that the expressions of global regulators sarA, agrA, and α-hemolysin gene hla were downregulated by 10-HDA. These results indicate that 10-HDA could be used as a potential natural antimicrobial agent to control the biofilm formation and virulence of S. aureus.

Dose-Dependent Effects of Royal Jelly on Estrogen- and Progesterone-Induced Mammary Gland Hyperplasia in Rats

SCOPE

Royal jelly (RJ) has a wide range of biological functions, its effect on hyperplasia of the mammary gland (HMG) in mammals is unclear. This study aims to investigate the effect of RJ on HMG and the dose-response relationship of RJ in the treatment of HMG.

METHODS AND RESULTS

HMG rats are induced by intramuscular injection of estrogen (E2) and progesterone, and are treated with different doses of RJ (100, 200, 400, and 800 mg kg^-1 d^-1 ). As a result, RJ improves the expansion of acinar and breast tissue ducts, particularly at 100 and 800 mg kg^-1 d^-1 . These two doses also inhibit serum E2 and prolactin (PRL) secretion and increase serum progesterone secretion and the expression of estrogen receptor (ER)-β in the breast tissue. In addition, 800 mg kg^-1 d^-1 decrease and increase the mRNA expression of, respectively, hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary GnRH receptors (GnRH-R). The lowest dosage (100 mg kg^-1 d^-1 ) increases GnRH-R mRNA expression as well. However, the effects of 200 and 400 mg kg^-1 d^-1 RJ on the reproductive parameters of HMG are not significant, implying a dose-dependent effect.

CONCLUSION

RJ regulates endocrine dyscrasia in HMG rats and improves the breast tissue structure, indicating its potential in the prevention and treatment on HMG.

10-hydroxy-2-decenoic acid a bio-immunomodulator in tissue engineering; generates tolerogenic dendritic cells by blocking the toll-like receptor4

Dendritic cells (DCs), in response to the biomaterials, utilize toll-like receptors (TLRs) to become mature or tolerogenic through TLRs-dependent signaling pathways, especially TLR4. Regarding the physicochemical properties of biomaterials, some of such signaling pathways are activated. Unsaturated fatty acids have been explored as an antagonist for TLRs and lead to the tolerogenic phenotype of DCs. Here we showed that, although cultured DCs on both chitosan and Alginate-polyethyleneimine (Alg-PEI) films became fully mature, 10-hydroxy-2-decanoic acid (10-HDA), an unsaturated fatty acid found in royal jelly, led to the tolerogenic immunophenotype of DCs on both films. The cultured cells on the films possessed iDCs-like morphology in the presence of 10-HDA. Moreover, 10-HDA expressed lower levels of CD80, CD83, CD86, and HLA-DR, a higher level of IL-10, and lower level of IL-12 in the cultured DCs on both films. Furthermore, HEK293T cells expressing only TLR4 (HEK-TLR4 cells) were co-cultured with LPS, a specific agonist for TLR4, and 10-HDA. The 10-HDA significantly reduced the expression of tumor necrosis factor-a (TNF-α) in the HEK-TLR4 cells compared to treated only with LPS. These findings indicate that the 10-HDA acts as an antagonist of TLR4; therefore, potentially can be used in autoimmune diseases and preventing the rejection of biomaterials implantation and allograft transplantation.

Preparation and Evaluation of Microcapsules Encapsulating Royal Jelly Sieve Residue: Flavor and Release Profile

This study aimed to improve the flavor of royal jelly residue via microencapsulation technology using Arabic gum and gelatin as wall materials. This microencapsulation technology showed a good encapsulation yield of 85.71 ± 2.84% and encapsulation efficiency of 92.34 ± 3.17%. The intact structures of the microcapsules were observed using optical and scanning electron microscopes. The results of the simulated gastrointestinal digestion proved that the microcapsules were well-tolerated in the gastric environment (a release rate of 32.95 ± 2.34%). Both electronic nose and electronic tongue evaluations showed that microencapsulation improved the sensory index of the royal jelly sieve residue. After microencapsulation, the astringency, bitterness, and irritant odors of the royal jelly residue were reduced. Simultaneously, the release rate in the intestine was 98.77 ± 1.91%, which demonstrated that microencapsulation would not prevent the human body from absorbing the royal jelly. The results from this study are expected to facilitate the development of mild flavor products made from royal jelly.

Royal jelly attenuates nonalcoholic fatty liver disease by inhibiting oxidative stress and regulating the expression of circadian genes in ovariectomized rats

Nonalcoholic fatty liver disease (NAFLD) has a high incidence in postmenopausal women and is accompanied by insulin resistance, obesity, and dyslipidemia. Royal jelly (RJ), a natural substance derived from hive, possesses numerous health-beneficial properties. Here, we evaluated the effects of RJ (150, 300, and 450 mg kg^-1  day^-1 , 8 weeks) on NAFLD in ovariectomized (OVX) rats. Based on the results, RJ ameliorated the degree of anxiety, improved serum lipid profile, and attenuated the hepatic steatosis and liver injury in OVX rats. Furthermore, the protective effects of RJ could be attributed to its antioxidant properties, which enhance the levels of hepatic antioxidant enzymes. The qRT-PCR results also suggest that RJ improves the disturbances of circadian genes by downregulating their expression, including that of Per1 and Per 2, in the liver of OVX rats. Altogether, our findings suggest that RJ may be a promising agent for the treatment of NAFLD. PRACTICAL APPLICATIONS: Postmenopausal women are at an increased risk of NAFLD. Currently, there are no licensed therapies for NAFLD. Although hormone replacement therapy (HRT) is reported to inhibit the development of NAFLD, it causes unexpected adverse effects. As HRT is controversial, the use of natural supplements to counteract the detrimental effects of menopause has recently attracted more attention. RJ is a natural product secreted from the hypopharyngeal and mandibular glands of worker bees. The present study illustrates the protective effect of the natural product, RJ, and its underlying mechanisms on NAFLD. This is the first study to assess the effect of RJ on NAFLD under estrogen deficiency. Such findings contribute to the further utilization of RJ, which might serve as a promising therapeutic option and natural food for the treatment of NAFLD.

Trans-10-hydroxy-2-decenoic acid protects against LPS-induced neuroinflammation through FOXO1-mediated activation of autophagy

PURPOSE

Neuroinflammation is thought to be associated with the pathogenesis of a series of neurodegenerative diseases. We have previously reported that royal jelly (RJ) has an anti-inflammatory effect on microglial BV-2 cells. However, components contributing to the effect of RJ were largely unexplored. The aim of this study was to assess whether trans-10-hydroxy-2-decenoic acid (10-HDA), the exclusive fatty acid in RJ, can alleviate neuroinflammation and to further explore the underlying mechanisms.

METHODS

Immunohistochemistry staining, ELISA, qRT-PCR and Western blot were used to assess the effect of 10-HDA on LPS-induced neuroinflammation both in vivo and in vitro. To determine the extent of inflammatory changes after 10-HDA treatment, RNAseq transcriptomic analysis was conducted.

RESULTS

10-HDA pretreatment significantly reduced the production of pro-inflammatory mediators in LPS-treated C57BL/6J mice and microglial BV-2 cells. 10-HDA inhibited the activation of the TNF-α/NF-κB axis and NLRP3 inflammasome-IL-1β pathway, which may be the anti-neuroinflammatory mechanism of 10-HDA. We also demonstrated that 10-HDA triggered cell autophagy, as evidenced by elevated levels of microtubule-associated protein 1 light chain 3-II (LC3-II) and decreased expression of SQSTM1. More importantly, 10-HDA increased the transcriptional activity of FOXO1 by increasing FOXO1 nuclear localization. Inhibition of FOXO1 and autophagy using chemical inhibitors markedly blunted the effect of 10-HDA on the TNF-α pathway and NLRP3 inflammasome-IL-1β pathway, indicating that 10-HDA alleviates neuroinflammation in BV-2 cells by modulating FOXO1-mediated autophagy.

CONCLUSIONS

10-HDA may be a promising agent for various neuroinflammation-associated diseases.

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.