The purpose of this study was to investigate the effects of melittin on production performance, antioxidant function, immune function, heat shock protein, intestinal morphology, and cecal microbiota of heat-stressed quails. A total of 120 (30-day-old) male quails were randomly divided into 3 groups. Each group consisted of 4 replicates with 10 birds per replicate. The ambient temperature of the control group (group W) was 24°C ± 2°C. The heat stress group (group WH) and the heat stress + melittin group (group WHA2) were subjected to heat stress for 4 h from 12:00 to 16:00 every day, and the temperature was 36°C ± 2°C for 10 d. The results showed that compared with the group W, heat stress significantly decreased growth performance, serum and liver antioxidative function, immune function, intestinal villus height (VH) and villus height-to-crypt depth ratio (VH/CD), and cecal microbiota Chao and ACE index (P < 0.05). The crypt depth (CD) in the small intestine, and HSP70 and HSP90 mRNA levels in the heart, liver, spleen, and kidney were significantly increased (P < 0.05). Dietary melittin significantly increased growth performance, serum and liver antioxidative function, immune function, intestinal VH and VH/CD, and cecal microbiota Shannon index in heat-stressed quails (P < 0.05). Melittin significantly decreased small intestinal CD, and HSP70 and HSP90 mRNA levels in the viscera (P < 0.05). Furthermore, dietary melittin could have balanced the disorder of cecal microbiota caused by heat stress and increased the abundance and diversity of beneficial microbiota (e.g., Firmicutes were significantly increased). PICRUSt2 functional prediction revealed that most of the KEGG pathways with differential abundance caused by high temperature were related to metabolism, and melittin could have restored them close to normal levels. Spearman correlation analysis showed that the beneficial intestinal bacteria Anaerotruncus, Bacteroidales_S24-7_group_norank, Lachnospiraceae_unclassified, Shuttleworthia, and Ruminococcaceae_UCG-014 increased by melittin were positively correlated with average daily feed intake, the average daily gain, serum and liver superoxide dismutase, IgG, IgA, bursa of Fabricius index, and ileum VH and VH/CD. In sum, our results demonstrate for the first time that dietary melittin could improve the adverse effects of heat stress on antioxidant function, immune function, heat shock protein, intestinal morphology, and cecal microbiota in quails, consequently improving their production performance under heat stress.

To study the effects of melittin on egg-laying performance and intestinal barrier of quails, 240 quails (aged 70 d) were randomly divided into 4 groups with 6 replicates (10 quails per replicate). They were fed with basal diet (group B), basal diet + 0.08 g/kg melittin (group BA1), basal diet + 0.12 g/kg melittin (group BA2) and basal diet + 0.16 g/kg melittin (group BA3). The experiment lasted for 21 days. The eggs were collected every day. At the end of the experiment, duodenal, jejunal, and ileal tissues were collected, and the cecal contents were sampled. Intestinal antioxidant index, barrier function, and intestinal flora were analyzed. The results showed that the addition of melittin significantly increased the laying rate and average egg weight. Addition of melittin significantly increased the antioxidant function, mechanical barrier, immune barrier, and the villus height to crypt depth ratio of small intestine. Addition of melittin had no significant effect on the α and β diversity of cecal flora, but significantly increased the abundance of Bacteroidales at family level and genus level. Bioinformatics analysis of cecal content showed significant increase in COG functional category of cytoskeleton, and significant decrease in RNA processing and modification in group BA2. KEGG functional analysis showed significant decrease in steroid biosynthesis, caffeine metabolism, and cytochrome P450 pathways in group BA2. In conclusion, addition of 0.12 g/kg melittin to feed improved the laying performance and the intestinal antioxidant capacity and barrier function of quails but had no significant effect on the composition and structure of cecal microbial community. This study provides experimental data and theoretical basis for the application of melittin as a new quail feed additive.

Objectives: Ferulic acid is a natural and safe herbal feed additive. This study aims to evaluate the effects of ferulic acid on the growth performance, anti-inflammatory and antioxidant capacities, immune function, and intestinal microbiota of broiler chickens. Methods: A total of 320 broiler chickens, aged 14 days, were randomly divided into four groups: a blank control group (MA group), a low-concentration ferulic acid group (BM group, 10 mg/kg), a medium-concentration ferulic acid group (CM group, 30 mg/kg), and a high-concentration ferulic acid group (DM group, 90 mg/kg) after a 14-day acclimatization period. The experiment lasted for 28 days, and the chickens were dissected on day 29. Results: The results showed that compared to the MA group, the feed-to-meat ratio in the CM and DM groups was significantly reduced. The activity of duodenal trypsin in the CM and DM groups was significantly enhanced, and the activity of pancreatic protease in the DM group was significantly increased. The serum levels of urea nitrogen, creatinine, and triglycerides were significantly elevated in the CM and DM groups. The serum malondialdehyde (MDA) levels in the BM, CM, and DM groups were significantly reduced, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were significantly increased in the CM and DM groups. The serum interleukin-2 (IL-2) levels in the BM group were significantly decreased, while interferon-gamma (IFN-γ) levels in the CM group and complement component 3 (C-3) levels in the DM group were significantly increased. The mRNA expression levels of TLR4, MyD88, NF-κB, TNF-α, NLRP3, IL-1β, and IL-18 in the jejunum of the DM group were significantly reduced. The diversity of cecal microbiota in the ferulic acid groups changed, with a certain degree of increase in the relative abundance of Spirulina and Ruminococcus. The relative abundance of Escherichia coli in the DM group significantly increased, altering the metabolic function of the cecal microbiota in broiler chickens. Conclusions: The above results indicate that ferulic acid, as a novel feed additive for broiler chickens, has an impact on the growth performance, anti-inflammatory and antioxidant capacity, immune function, and intestinal microbiota of broiler chickens.

Phytochemical investigation the resins of Ferula sinkiangensis K.M.Shen yielded three new tetrahydrobenzofuran derivatives named as Sinkiangensis A-C (1–3). The structures of the new compounds were elucidated by analysis of their NMR, HRMS, and ECD spectra, and the absolute configurations were established through the comparison of experimental and calculated ECD spectra. Compound 3 exhibited moderate antitumor activities against AGS cancer cell with IC₅₀ values of 15.6 µM. Moreover, assays demonstrated that compound 3 could induce AGS cancer cell apoptosis. Graphical Abstract