Protective role of Cecropin AD against LPS-induced intestinal mucosal injury in chickens

Effects of cecropin antimicrobial peptides on growth and intestinal health in growing male minks

This study investigated the effects of dietary supplementation with cecropin antimicrobial peptides (CAD) on growth performance and intestinal health in growing male minks (Neovison vison). A cohort of 60 male minks (65 days old) were evenly divided into six groups and fed a basal diet supplemented with CAD at 0 (control), 100, 200, 300, 400, or 500 mg/kg for 8 weeks. The findings revealed that the minks in 200 mg/kg CAD group had greater growth performance, with significantly higher final body weight (FBW) and average daily gain (ADG). Compared to the minks in the control (p < 0.05). Digestibility analyses at week 3 demonstrated that CAD supplementation enhanced ether extract (EE) digestibility (p < 0.05), while 200, 400, and 500 mg/kg CAD improved crude protein (CP) digestibility (p < 0.05). Intestinal morphology assessments indicated that 200 mg/kg CAD significantly increased duodenal and jejunal villus height (both p < 0.05) and jejunal villus height-to-crypt depth ratio (p < 0.05) compared to the control. Serum immunological analyses revealed elevated levels of complement C4 and IgG in CAD-supplemented groups (p < 0.05). Notably, the 100 mg/kg CAD group exhibited the higher serum IgA, IgM, and complement C3, and less jejunal TNF-α levels (all p < 0.05). Microbiota profiling showed that CAD supplementation reduced the relative abundance of Escherichia-Shigella and Mycoplasma, while 100, 200 and 400 mg/kg CAD decreased Peptostreptococcaceae populations (p < 0.05). The 100 mg/kg CAD group displayed optimal immune enhancement and microbiota modulation, whereas the 200 mg/kg group achieved the best growth performance and intestinal function. These results suggest that dietary CAD supplementation at 100-200 mg/kg effectively improves growth, nutrient utilization, and intestinal health in growing male minks.

Baicalin enhances respiratory mucosal immunity by modulating antiviral protein expression and T-cell homeostasis during H9N2 infection

Introduction

The H9N2 avian influenza virus, although not highly pathogenic, still poses ongoing risks to poultry health and food security due to its ability to resist vaccines and its potential to spread to humans.

Methods

This study investigated the effects of baicalin, a flavonoid derived from Scutellaria baicalensis, on respiratory mucosal immunity during H9N2 infection. In vitro experiments were conducted using MLE-12 alveolar epithelial cells, and in vivo evaluations were performed in a mouse model of H9N2 infection.

Results

Baicalin treatment enhanced the expression of antiviral proteins Mx1 and PKR in a dose- and time-dependent manner, helping to counteract the virus's suppression of these defense proteins. In addition to strengthening this epithelial barrier, baicalin has both antiviral and immune-regulating effects: it directly blocks viral replication and helps restore the CD4+/CD8+ T cell ratio in H9N2-infected mice. Most importantly, baicalin reduces lung damage and spleen shrinkage while keeping the immune system balanced. These results show that baicalin enhances mucosal antiviral defenses by simultaneously regulating innate antiviral pathways (Mx1 and PKR) and restoring adaptive immune balance (CD4+/CD8+ T-cell ratio).

Discussion

These dual protective effects highlight baicalin's potential as a natural therapeutic strategy for improving mucosal immunity against vaccine-resistant influenza viruses such as H9N2, contributing valuable insights into plant-derived immunomodulatory approaches against emerging zoonotic viral threats.

Brown Algae Polysaccharides Alleviate Diquat-Induced Oxidative Stress in Piglets and IPEC-J2 Cells via Nrf2/ARE Signaling Pathway

This study investigated the effect of Brown algae polysaccharides (BAPs) on diquat-induced oxidative stress in piglets and IPEC-J2 cells through Nrf2/ARE signaling pathway. In the in vivo model, 24 male piglets of the Duroc × Landrace × Large White breed were selected and divided into 4 groups (n = 6), including the CON group (basal diet), DIQ group (10 mg/kg Diquat), BAP group (1000 mg/kg BAP), and BAP+DIQ group (1000 mg/kg BAP + 10 mg/kg Diquat). Compared with the DIQ group, BAP improved growth performance and the BAP+DIQ group reduced the levels of IL-1β, IL-6, TNF-α, and DAO in plasma, increased VH and VCR, improved jejunal tissue morphology, decreased MDA levels, and increased T-AOC (p < 0.05). Additionally, the BAP+DIQ group elevated mRNA levels of ZO-1, and enhanced the protein levels of Occludin, Claudin1, CAT, SOD1, and HO-1 (p < 0.05). In the in vitro model, the BAP+DIQ group decreased MDA levels, increased T-AOC, elevated mRNA levels of ZO-1, CAT and SOD2, as well as protein levels of Claudin1, SOD1, HO-1, and total Nrf2 compared with the DIQ group (p < 0.05). Furthermore, BAP increased nuclear Nrf2 protein levels, and promoted the translocation of Nrf2 from the cytoplasm to the nucleus compared with the DIQ group (p < 0.05). In conclusion, BAPs are crucial for enhancing piglets' antioxidant capacity via Nrf2 pathway activation. These findings highlight BAP's potential as a natural feed additive to mitigate oxidative stress and improve overall health in piglets. Further research is warranted to explore BAPs as a dietary supplement to support gut health and reduce oxidative stress.

Effects of Sea-Buckthorn Flavonoids on Growth Performance, Serum Inflammation, Intestinal Barrier and Microbiota in LPS-Challenged Broilers

The experiment investigated the effects of sea-buckthorn flavonoids (SF) on lipopolysaccharide (LPS)-challenged broilers. A total of 288 one-day-old male broilers were randomly assigned to 4 groups, with 6 replicates of 12 broilers each. The experiment lasted for 20 days. The diet included two levels of SF (0 or 1000 mg/kg) and broilers intraperitoneally injected with 500 μg/kg LPS on 16, 18, and 20 days, or an equal amount of saline. LPS challenge decreased final body weight, average daily gain, and average daily feed intake, increased feed-to-gain ratio, and elevated serum IL-1β, IL-2, TNF-α, D-LA, and endotoxin levels. Moreover, it resulted in a reduction in the IL-10 level. LPS impaired the intestinal morphology of the duodenum, jejunum, and ileum, down-regulated the mRNA relative expression of Occludin, ZO-1, and MUC-2 in the jejunum mucosa, up-regulated the mRNA relative expression of TLR4, MyD88, NF-κB, and IL-1β, and increased the relative abundance of Erysipelatoclostridium in broilers (p < 0.05). However, SF supplementation mitigated the decrease in growth performance, reduced serum IL-1β, IL-2, and D-LA levels, increased IL-10 levels, alleviated intestinal morphological damage, up-regulated mRNA expression of Occludin and ZO-1, down-regulated the mRNA expression of TLR4, NF-κB, and IL-lβ in jejunum mucosal (p < 0.05), and SF supplementation presented a tendency to decrease the relative abundance of proteobacteria (0.05 < p < 0.1). Collectively, incorporating SF can enhance the growth performance, alleviate serum inflammation, and improve the intestinal health of broilers, effectively mitigating the damage triggered by LPS-challenges.

Cecropin AD reduces viral load and inflammatory response against H9N2 avian influenza virus in chickens

Introduction

This study focuses on evaluating the therapeutic efficacy of cecropin AD, an antimicrobial peptide, against H9N2 avian influenza virus (AIV) in chickens. Given the global impact of H9N2 AIV on poultry health, identifying effective treatments is crucial.

Methods

To assess the impact of cecropin AD, we conducted in vivo experiments involving 108 5-week-old chickens divided into control, infected, and various treatment groups based on cecropin AD dosage levels (high, medium, and low). The methodologies included hemagglutination (HA) tests for viral titers, histopathological examination and toluidine blue (TB) staining for lung pathology, real-time PCR for viral detection, and enzyme-linked immunosorbent assays for measuring serum levels of inflammatory markers.

Results

The findings revealed that cecropin AD substantially reduced lung pathology and viral load, especially at higher dosages, comparing favorably with the effects seen from conventional treatments. Moreover, cecropin AD effectively modulated mast cell activity and the levels of inflammatory markers such as IL-6, TNF-α, IFN-γ, and 5-HT, indicating its potential to diminish inflammation and viral spread.

Discussion

Cecropin AD presents a significant potential as an alternative treatment for H9N2 AIV in chickens, as evidenced by its ability to lessen lung damage, decrease viral presence, and adjust immune responses. This positions cecropin AD as a promising candidate for further exploration in the management of H9N2 AIV infections in poultry.