Fengyang Wu

This study aimed to investigate the effects of dietary supplementation with different levels of ursolic acid (UA) on the growth performance, immune function, intestinal antioxidant capacity, and anti-inflammatory responses of weaned rabbits. A total of 160 Hyla meat rabbits aged 35 days were randomly assigned to four groups. Each treatment group consisted of 8 replicates, with 5 rabbits per replicate. The rabbits were fed a basal diet (control group, CON) or experimental diets supplemented with 50, 100, or 200 mg/kg UA for 28 days. Dietary supplementation with 50 mg/kg UA significantly increased (p < 0.05) the average daily gain and average daily feed intake. The villus height, crypt depth, and villus height to crypt depth ratio exhibited quadratic responses (p < 0.05) to increasing dietary UA levels, with rabbits fed 50 mg/kg UA showing optimal ileal morphology. Compared with the CON group, dietary supplementation with 50 mg/kg UA significantly enhanced (p < 0.05) cecal catalase activity, secretory immunoglobulin A, and interleukin-10 (IL-10) levels, while the addition of 200 mg/kg UA increased (p < 0.05) serum catalase activity. The concentrations of serum tumor necrosis factor-α (TNF-α) and cecal IL-10 responded quadratically (p < 0.01 and p = 0.01, respectively) as the dietary UA level increased. With increasing UA supplementation, cecal Kelch-like ECH-associated protein 1 and IL-10 mRNA expression showed linear upregulation (p < 0.05), whereas nuclear factor erythroid 2-related factor 2 (Nrf2), superoxide dismutase 1 (SOD1), quinone oxidoreductase 1 (NQO1), TNF-α, interleukin-6, and interleukin-8 displayed quadratic responses (p < 0.05). Dietary UA at 50 mg/kg significantly downregulated cecal TNF-α and interleukin-1β mRNA expression while upregulating Nrf2, NQO1, and SOD1 mRNA levels (p < 0.05). In conclusion, dietary supplementation with 50 mg/kg UA significantly improved the growth performance of weaned rabbits by improving intestinal morphology, immune function, and antioxidant and anti-inflammatory capacities, demonstrating its efficacy as a natural phytogenic feed additive.

Ursolic acid (UA) has demonstrated significant immunomodulatory and hepatoprotective effects; however, the underlying mechanisms remain unclear. This study aims to analyze the impact of UA on the gut microbiome, metabolome, and liver transcriptome, investigate UA’s role in maintaining gut immune homeostasis and liver health, and evaluate the potential contributions of gut microbes and their metabolites to these beneficial effects. Our findings indicate that UA enhances immune balance in the jejunum, fortifies intestinal barrier function, and promotes overall gut health. UA modulates the intestinal microbiota and its metabolic processes, notably increasing the abundance of beneficial bacteria such as Odoribacter and Parabacteroides, along with their metabolites, including ornithine and lactucin. Additionally, UA inhibits the expression of interleukin-1 receptor 1 (IL1R1) and calcium (Ca²⁺) voltage-gated channel auxiliary subunit beta 2 (CACNB2) while enhancing the synthesis pathways of retinol and ascorbic acid, thereby exerting a protective influence on liver function. In summary, UA enhances intestinal immune homeostasis and promotes liver health, with these advantageous effects potentially mediated by beneficial bacteria (Odoribacter and Parabacteroides) and their metabolites (ornithine and lactucin).

This study investigated the dietary effect of curcumin (CUR) on amino acid, 5′-nucleotides, fatty acid, and volatile compound profiles of chicken meat. A total of 400 healthy 1-day-old broiler male chicks were divided into 4 groups (n = 10) and fed either a basal diet or a diet with the addition of CUR with concentrations of 100 mg/kg, 150 mg/kg, and 200 mg/kg for 43 days. The results show that the addition of CUR in chicken diets is conducive to promoting the deposition of amino acids and increasing the content of 5′-nucleotides in chicken meat, reducing the contents of saturated fatty acid (SFA) and C20:4 n6 but increasing the ratio between polyunsaturated fatty acid (PUFA) and SFA. In addition, the volatile compound profile shows that the main volatile compounds in chicken meat are aldehydes (including hexanal, heptanal, octanal, and nonanal), with significant increases in their contents observed among chickens in the CUR-intake group. Moreover, it has been found that (E, E)-2,4-nonadienal, trans-2-decenal, benzaldehyde, and trans-2-octenal in chicken meat can significantly increase its overall aroma, and the addition of CUR with 150 mg/kg had the best effect on improving nutritional quality and flavor of chicken meat. This study provides a basis for the comprehensive utilization of CUR as a feed additive with the potential to substitute antibiotics.

Zearalenone (ZEA) is a kind of mycotoxin that pose great threat to the liver of human and livestock due to its toxicity to eukaryotic cells, however, its toxicity mechanism on prepubertal gilts liver development and function is not known. The study aimed to examine the effects of ZEA on liver development, antioxidant capacity and inflammatory factors of prepubertal gilts. Forty‐eight prepubertal gilts (Landrace ×Yorkshire) were randomly divided into four groups: three treatment (T1, T2 and T3) groups and a control group. Prepubertal gilts in the control group were fed with basal diet, and those in T1, T2 and T3 groups were fed with basal diets supplemented with low, medium and high doses (200 μg/kg, 800 μg/kg and 1,600 μg/kg, respectively) of ZEA during the experiment period. The results showed that diets supplemented with ZEA significantly increased the activity of alanine aminotransferase of serum in the T3 group (p < 0.05). Besides, compared to the control group, the activities of total antioxidant capacity, superoxide dismutase, the content of tumour necrosis factor‐alpha of liver in the T3 group and the relative expression level of manganese‐superoxide dismutase mRNA of liver in the T2 group were significantly reduced (p < 0.05). We also performed correlation analysis among caecal microorganisms and antioxidant enzyme activities and inflammatory factor concentrations of liver. In conclusion, diets supplemented with ZEA has no obvious effect on liver development, but it can cause liver damage.