ABSTRACT
The intestine is highly vulnerable to various factors and has been proposed as a promising determinant for poultry health. Phytogenic or plant-derived feed additives can be used to help improve intestinal health. In this study, we aimed to investigate the effects of DNJ on the antioxidative parameters, including malondialdehyde (MDA), total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and inflammatory cytokines (IL-6, IL-1ß, and TNF-α), in plasma and intestinal tissues using layers supplemented with or without the DNJ extract of mulberry leaves (DNJ-E) via the ELISA method. A total of 192 healthy Hy-Line Brown layers, aged 47 weeks old, were used to conduct a 56-day study. All hens were randomly separated into four groups as follows: a basal diet containing 0 mg/kg DNJ-E(CON), 50 mg/kg, 100 mg/kg, and 150 mg/kg DNJ-E. Furthermore, the potential mechanism by which DNJ influences intestinal function was also investigated in in vitro cultured intestinal epithelium cells (IEC) with quantification methods including the use of a cell counting kit-8 (CCK8), ELISA, qRT-PCR, and ROS detection. The results showed that CAT in plasma significantly increased following 50 mg/kg DNJ-E supplementation. Moreover, 50 mg/kg DNJ-E supplementation was associated with increases in T-SOD in the jejunum and ileum. However, there was no significant difference in inflammatory cytokines between groups in in vivo experiments. Subsequent in vitro IEC studies revealed that cell viability increased significantly following 5 µM and 10 µM DNJ treatments while decreasing significantly following 20 µM DNJ treatment. Antioxidative parameters improved at 5 µM and 10 µM DNJ concentrations. However, there were no ameliorative effects on antioxidant parameters observed under 20 µM DNJ treatment. The expression levels of Nrf2 mRNA increased significantly under DNJ treatment. DNJ treatment was associated with significant changes in the expression of genes of inflammatory cytokines. In conclusion, our study revealed that DNJ could improve oxidative stress and inflammation responses in the chicken intestine. These findings provide a theoretical reference for the development of functional feed additives that regulate intestinal health and lay the foundation for systematically revealing the mechanism of DNJ.
ABSTRACT
Quercetin (Que), widely found in a huge variety of plants, plays important roles in ovarian function. However, to data, there have been no reports about Que regulating granulosa cells (GCs) in prehierarchical follicles in chicken. Herein, GCs from follicles diameter from 4 to 8 mm in chicken were treated by Que in vitro culture to investigate how Que exerts its effect on follicular development. GCs treated by Que in concentrations of 10, 100, and 1,000 ng/mL were tested for cell proliferation and progesterone secretion. Eight cDNA libraries were constructed from GCs (4 samples per group) to explore transcriptome expression changes. The role of the MAPK/ERK signaling pathway was validated in this process. Treatment with 100 and 1,000 ng/mL levels of Que significantly promoted cell proliferation and progesterone secretion (P < 0.05). RNA-seq analysis data showed that 402 and 263 differentially expressed genes (DEGs) were up- and down-regulated, respectively. Functional enrichment analysis that the pathways related to follicular development included biosynthesis of amino acids, MAPK signaling pathway, and calcium signaling pathway. Notably, the function exerted in GCs of the different levels of Que was associated with the suppression of the MAPK pathway. In conclusion, our results proved that low levels of Que could promote MAPK signaling pathway, but high levels of Que inhibit MAPK signaling pathway in GCs from the prehierarchical follicles, promote cell proliferation and progesterone secretion, and benefit follicle selection.
