Zhen Li

Triadica cochinchinensis honey (TCH) is a specialty honey with strong antioxidant activity. However, its key antioxidant components and underlying mechanisms remain unclear. This study systematically evaluated the antioxidant effects and mechanisms of TCH using metabolomics, transcriptomics, and network pharmacology. The results revealed that TCH exhibited higher 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) radical scavenging activity and ferric ion reducing antioxidant power (FRAP) capacity than nine common commercial honeys. Metabolomic analysis identified D-chiro-inositol as a key antioxidant compound, which, together with (-)-gallocatechin gallate, identified in prior research, constitutes the core antioxidant monomers of TCH (TCMs). TCH and TCMs protected LO2 cells against hydrogen peroxide (H2O2)-induced oxidative damage by increasing cell viability, reducing malondialdehyde (MDA) and reactive oxygen species (ROS) levels, enhancing antioxidant enzyme activities and total antioxidant capacity, suppressing apoptosis, and reversing G0/G1 cycle arrest. Transcriptomics and network pharmacology analyses revealed that the potential cellular protective mechanism of TCMs may involve a multi-target antioxidant network by regulating oxidative stress-related genes within key signaling pathways, including mitogen-activated protein kinase (MAPK), tumor necrosis factor (TNF), and epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance pathways, in H2O2-damaged cells.

The primary objective of this study was to investigate the mechanism through which small peptides regulate the productive performance and egg quality of laying hens during the late-laying period. A total of 200 Lohmann Pink laying hens, aged 400 days, were randomly assigned into a control treatment (CON) and a small peptide treatment (SP) for a 120-day treating period. Productive performance, egg quality, serum antioxidant capacity, intestinal morphology, microbial community, and hepatic gene expressions were measured. Results showed that SP supplementation significantly increased eggshell strength and albumen height, while reducing the rate of abnormal eggs (p < 0.05). SP notably enhanced the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and hepatic lipase (p < 0.05). Additionally, SP supplementation significantly increased microbial α-diversity (p < 0.05) and elevated the relative abundances of Ruminococcus, Lactobacillus, and Faecalibacterium (p < 0.05). Hepatic transcriptomic analysis revealed that up-regulated genes in the SP treatment were primarily enriched in steroid biosynthesis, while down-regulated genes were mainly associated with the Yersinia infection pathway. In conclusion, small peptide supplementation efficiently improved eggshell strength and albumen height while reducing the rate of abnormal eggs by modulating the interactions between gut microbiota and hepatic gene expressions. Our findings may provide an effective option for enhancing egg quality in the late-laying period.

The annual nitrogen loss from the livestock production sector poses a significant threat to the global natural environment. Therefore, it is urgent to focus on improving the nutrient utilization efficiency of ruminants and promoting the sustainable development of livestock production. Twelve 60-day-old Ganxi goats with similar body weights were selected and randomly assigned to two dietary treatment groups. The control group was fed only a basal diet, while the treatment group was supplemented with 32 mg/d of Swollenin. The experiment lasted for 30 days. At the end of the experimental period, the goats were euthanized, and their intestinal contents were collected, rapidly frozen, and stored at −80 °C for subsequent metagenomic and metabolomic analyses. In the Swollenin group, we observed changes in gut microbiota structure and significantly enhanced feed conversion efficiency compared to the control group. Notably, genera such as Bacteroides, Ruminococcus, and Bifidobacterium exhibited significantly higher abundance. Following Swollenin supplementation, the gene abundance associated with the secondary bile acid biosynthesis pathway in the intestinal tract of young goats was significantly higher. The levels of primary bile acids (BAs), including taurocholic acid, glycocholic acid, taurochenodeoxycholic acid, and glycochenodeoxycholic acid, were significantly lower, while the concentrations of secondary BAs such as ursodeoxycholic acid and deoxycholic acid were significantly higher. The abundance of nitrogen-fixing and nitrogen-assimilating genes in the gut of young goats in the Swollenin group was significantly higher. Furthermore, co-occurrence network analysis revealed a strong correlation between bile acid metabolism and nitrogen metabolism pathways. These results suggest that nutritional regulation may serve as a preventive strategy to optimize the symbiotic development of animals and their gut microbiota, ultimately improving nitrogen utilization.

油茶因自交不亲和导致授粉效率低下，而利用蜜蜂授粉时，其花蜜中的棉籽糖家族寡糖(Raffinose family of oligosaccharides, RFOs)会引发蜜蜂中毒。本研究旨在通过重构巴斯德毕赤酵母(Pichia pastoris)表达油茶地蜂(Andrena camellia)的3种半乳糖代谢关键酶（半乳糖激酶，Galactokinase, GALK；半乳糖-1-磷酸尿苷转移酶，Galactose-1-phosphate uridyltransferase，GALT；尿苷二磷酸-4'-变位酶，Uridine diphosphate galactose-4’-epimerase，GALE），探究其对蜜蜂寡糖解毒能力的提升效果。通过质粒重组技术构建pPIC9K-GALK/GALT/GALE表达载体，电转化至巴斯德毕赤酵母(GS115)中，经诱导表达获得重组酶。通过Western Blot验证蛋白表达，并检测酶活性。体外实验评估酶对半乳糖的代谢效率，同时以添加重组酶的糖水饲喂西方蜜蜂（Apis mellifera）工蜂，统计其存活率及中位生存期。成功实现GALK、GALT和GALE在巴斯德毕赤酵母中的高效表达。体外消化实验表明，三酶联用可使半乳糖含量显著降低（P < 0.05），并检测到Leloir途径代谢产物（UDP-葡萄糖）。饲喂实验显示：饲喂添加3种酶的糖水的工蜂平均寿命较对照组显著延长34.43%（P < 0.05）。巴斯德毕赤酵母表达的GALK、GALT和GALE可有效代谢油茶寡糖中的半乳糖，显著缓解蜜蜂中毒症状。本研究为生物工程法改良蜜蜂代谢能力提供了技术支撑，对推动油茶产业可持续发展具有重要意义。

Although mature bee bread is a key natural bee product, comprehensive metabolite profiles remain incomplete. This study compared Brassica napus bee bread metabolomes from Apis mellifera (BAM) and A. cerana (BAC) using LC-MS broad-target metabolomics. We identified 1090 metabolites across 19 compound classes, with 269 differentially expressed between species. Variation depended critically on bee species, including primary metabolites (42 organic acids, 38 lipids, 21 amino acids/derivatives, 19 saccharides) and secondary metabolites (29 flavonoids, 10 phenols). Results demonstrate significant chemical composition differences in bee bread brewed by different honey bee species. Thus, assessing species-specific biological and pharmacological compositional differences is essential before developing bee bread into wellness or functional foods.

Metabolites present in the hemolymph of honey bees play a crucial role in modulating the metamorphic process within the species. However, the precise alterations in metabolite composition, along with the associated variances and regulatory pathways implicated during the larvae-to-pupae metamorphosis of honey bees, remain incompletely elucidated. In this investigation, we gathered hemolymph samples from honey bee larvae at three distinct physiological stages-feeding, prepupal, and pupae and subjected them to metabolite analysis utilizing the liquid chromatography-mass spectrometry (LC-MS) technique. Employing principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA), we identified significant differential metabolites and conducted a metabolic pathway analysis on those differentially up-regulated during the prepupal and pupae stages. Notably, metabolites up-regulated in the hemolymph of prepupal stage larvae primarily governed glucose metabolism and fat digestion and absorption, while those in pupae stage larvae were involved in regulating chitin and lipopolysaccharide precursor formation, as well as the biosynthesis of phenylalanine, tyrosine, and tryptophan. These findings bear significant implications for advancing our comprehension of the metamorphic processes in honey bees.

Honey bees are important species for the study of epigenetics. Female honey bee larvae with the same genotype can develop into phenotypically distinct organisms (sterile workers and fertile queens) depending on conditions such as diet. Previous studies have shown that DNA methylation and histone modification can establish distinct gene expression patterns, leading to caste differentiation. It is unclear whether the histone methylation modification H3K4me1 can also impact caste differentiation. In this study, we analyzed genome-wide H3K4me1 modifications in both queen and worker larvae and found that H3K4me1 marks are more abundant in worker larvae than in queen larvae at both the second and fourth instars, and many genes associated with caste differentiation are differentially methylated. Notably, caste-specific H3K4me1 in promoter regions can direct worker development. Thus, our results suggest that H3K4me1 modification may act as an important regulatory factor in the establishment and maintenance of caste-specific transcriptional programs in honey bees; however, the potential influence of other epigenetic modifications cannot be excluded.

C. oleifera is an economically important oilseed crop and medical plant. However, as a characteristic honey resource, the standard protocol used to identify the composition of C. oleifera honey has not been established yet. Previously, distinctive flavonoid has been shown as an effective marker to trace the botanical origin of honey. In this study, we examined the flavonoid types in C. oleifera honey and nine other monofloral honeys by using liquid chromatography tandem-mass spectrometry (LC-MS/MS) and compared the differences and identified eight distinct flavonoids in C. oleifera honey. Then, comparing the 8 flavonoids with the 14 flavonoids common to C. oleifera honey and nectar, two distinct flavonoids were identified in C. oleifera honey and nectar. Finally, we identified kaempferitrin as the distinct flavonoid marker in C. oleifera honey using the degree of influence of the partial least-squares discriminant analysis (PLS-DA) model on C. oleifera honey and ployfloral honey.

RNA interference (RNAi) has been used successfully to reduce target gene expression and induce specific phenotypes in several species. It has proved useful as a tool to investigate gene function and has the potential to manage pest populations and reduce disease pathogens. However, it is not known whether different administration methods are equally effective at interfering with genes in bees. Therefore, we compared the effects of feeding and injection of small interfering RNA (siRNA) on the messenger RNA (mRNA) levels of alpha-aminoadipic semialdehyde dehydrogenase (ALDH7A1), 4-coumarate-CoA ligase (4CL), and heat shock protein 70 (HSP70). Both feeding and injection of siRNA successfully knocked down the gene but feeding required more siRNA than the injection. Our results suggest that both feeding and injection of siRNA effectively interfere with brain genes in bees. The appropriateness of each method would depend on the situation.