Anti-Cancer Effects of Queen Bee Acid (10-Hydroxy-2-Decenoic Acid) and Its Cellular Mechanisms against Human Hepatoma Cells

Biosynthesis of 10-Hydroxy-2-Decenoic Acid in Escherichia coli

10-hydroxy-2-decenoic acid (10-HDA), a unique unsaturated fatty acid present in royal jelly, has attracted considerable interest due to its potential medical applications. However, its low concentration in royal jelly and complex conformational structure present challenges for large-scale production. In this study, we designed and constructed a de novo biosynthetic pathway for 10-HDA in Escherichia coli. Initially, we introduced the heterologous thioesterase UaFatB1 to hydrolyze trans-2-decenoyl ACP to produce trans-2-decenoic acid, a key precursor for 10-HDA. Subsequently, we employed the bacterial cytochrome P450 enzyme CYP153AMaq to catalyze the terminal hydroxylation of trans-2-decenoic acid. Furthermore, through redox partner engineering and directed evolution, we identified the optimal combination for 10-HDA production: CYP153AMaq Q129R/V141L mutant with redox partner FdR0978/Fdx0338. Finally, we optimized the fermentation conditions and achieved a 10-HDA titer of 18.8 mg/L using glucose as primary carbon source. Our work establishes a platform for producing α,β-unsaturated fatty acids and their derivatives, facilitating further studies on these compounds.

Inhibitory Effects of Royal Jelly and Its Functional Components on the Proliferation of MKN-28 Gastric Cancer Cells

Royal jelly (RJ) is a natural food product with nutritional value and anticancer activity. However, their effects on gastric cancer are unclear. Here, we show that treatment with 5-320 μg/mL of RJ, ethanol extract (RJEE), and protein hydrolyzate (RJPH) decreased the viability of MKN-28 gastric cancer cells, with a half-maximal inhibitory concentration of 123.22 μg/mL for RJEE. RJ, RJEE, and RJPH increase the lactate dehydrogenase release rate and change the morphology of the cells, resulting in cell shrinkage, nucleoplasm condensation, and the formation of apoptotic bodies. RJ and its functional components stagnated the cell cycle in the G0/G1 phase, accompanied by the accumulation of reactive oxygen species, decreased mitochondrial membrane potential, and increased expression levels of p53 and p21 proteins, caspase-3 activation, and apoptosis. Therefore, RJ, RJEE, and RJPH have potential inhibitory effects on the proliferation of gastric cancer cells.

Antitumor Effects and the Potential Mechanism of 10-HDA against SU-DHL-2 Cells

10-hydroxy-2-decenoic acid (10-HDA), which is a unique bioactive fatty acid of royal jelly synthesized by nurse bees for larvae and adult queen bees, is recognized for its dual utility in medicinal and nutritional applications. Previous research has indicated that 10-HDA exerts antitumor effects on numerous tumor cell lines, including colon cancer cells, A549 human lung cancer cells, and human hepatoma cells. The present study extends this inquiry to lymphoma, specifically evaluating the impact of 10-HDA on the SU-DHL-2 cell line. Our findings revealed dose-dependent suppression of SU-DHL-2 cell survival, with an IC50 of 496.8 μg/mL at a density of 3 × 106 cells/well after 24 h. For normal liver LO2 cells and human fibroblasts (HSFs), the IC50 values were approximately 1000 μg/mL and over 1000 μg/mL, respectively. The results of label-free proteomics revealed 147 upregulated and 347 downregulated differentially expressed proteins that were significantly enriched in the complement and coagulation cascades pathway (adjusted p-value = 0.012), including the differentially expressed proteins prothrombin, plasminogen, plasminogen, carboxypeptidase B2, fibrinogen beta chain, fibrinogen gamma chain, and coagulation factor V. The top three hub proteins, ribosomal protein L5, tumor protein p53, and ribosomal protein L24, were identified via protein-protein interaction (PPI) analysis. This result showed that the complement and coagulation cascade pathways might play a key role in the antitumor process of 10-HDA, suggesting a potential therapeutic avenue for lymphoma treatment. However, the specificity of the effect of 10-HDA on SU-DHL-2 cells warrants further investigation.

Exploring the in vitro potential of royal jelly against glioblastoma and neuroblastoma: impact on cell proliferation, apoptosis, cell cycle, and the biomolecular content

Neuroblastoma and glioblastoma are the most commonly seen nervous system tumors, and their treatment is challenging. Relatively safe and easy acquisition of nutraceutical natural products make them suitable candidates for anticancer research. Royal jelly (RJ), a superfood, has many biological and pharmacological activities. This study was conducted to, for the first time, elucidate its anticancer efficiency, even in high doses, on neuroblastoma and glioblastoma cell lines through cell viability, apoptosis, cell cycle and biomolecular content evaluation. We performed experiments with RJ concentrations in the range of 1.25-10 mg mL-1 for 48 h. Cell viability assays revealed a notable cytotoxic effect of RJ in a concentration-dependent manner. Treatment with a high dose of RJ significantly increased the apoptotic cell population of both cell lines. Furthermore, we observed G0-G1 phase arrest in neuroblastoma cells but G2-M arrest in glioblastoma cells. All these cellular changes are closely associated with the alterations of the macromolecular makeup of the cells, such as decreased saturated lipid, protein, DNA and RNA amounts, protein conformational changes, decreased protein phosphorylation and increased protein carbonylation. These cellular changes are associated with RJ triggered-ROS formation. The clear segregation between the control and the RJ-treated groups proved these changes, obtained from the unsupervised and supervised chemometric analysis. RJ has good anticancer activity against nervous system cancers and could be safely used with current treatment strategies.

Discovery of Novel Mono-Carbonyl Curcumin Derivatives as Potential Anti-Hepatoma Agents

Curcumin possesses a wide spectrum of liver cancer inhibition effects, yet it has chemical instability and poor metabolic properties as a drug candidate. To alleviate these problems, a series of new mono-carbonyl curcumin derivatives G1-G7 were designed, synthesized, and evaluated by in vitro and in vivo studies. Compound G2 was found to be the most potent derivative (IC50 = 15.39 μM) compared to curcumin (IC50 = 40.56 μM) by anti-proliferation assay. Subsequently, molecular docking, wound healing, transwell, JC-1 staining, and Western blotting experiments were performed, and it was found that compound G2 could suppress cell migration and induce cell apoptosis by inhibiting the phosphorylation of AKT and affecting the expression of apoptosis-related proteins. Moreover, the HepG2 cell xenograft model and H&E staining results confirmed that compound G2 was more effective than curcumin in inhibiting tumor growth. Hence, G2 is a promising leading compound with the potential to be developed as a chemotherapy agent for hepatocellular carcinoma.

Metabolic Profile of Alzheimer's Disease: Is 10-Hydroxy-2-decenoic Acid a Pertinent Metabolic Adjuster?

Alzheimer's disease (AD) represents a significant public health concern in modern society. Metabolic syndrome (MetS), which includes diabetes mellitus (DM) and obesity, represents a modifiable risk factor for AD. MetS and AD are interconnected through various mechanisms, such as mitochondrial dysfunction, oxidative stress, insulin resistance (IR), vascular impairment, inflammation, and endoplasmic reticulum (ER) stress. Therefore, it is necessary to seek a multi-targeted and safer approach to intervention. Thus, 10-hydroxy-2-decenoic acid (10-HDA), a unique hydroxy fatty acid in royal jelly, has shown promising anti-neuroinflammatory, blood-brain barrier (BBB)-preserving, and neurogenesis-promoting properties. In this paper, we provide a summary of the relationship between MetS and AD, together with an introduction to 10-HDA as a potential intervention nutrient. In addition, molecular docking is performed to explore the metabolic tuning properties of 10-HDA with associated macromolecules such as GLP-1R, PPARs, GSK-3, and TREM2. In conclusion, there is a close relationship between AD and MetS, and 10-HDA shows potential as a beneficial nutritional intervention for both AD and MetS.