College of Life Science, Ludong University, Yantai 264000, Shandong, China.
Shandong Provincial Key Laboratory of Quality Safety Monitoring and Risk Assessment for Animal Products, Ji'nan 250022, Shandong, China.
J Vet Med Sci. 2020 Aug 28;82(8):1187-1196. doi: 10.1292/jvms.19-0571. Epub 2020 Jul 14.
Research on the composition and application of immune enhancers in livestock and poultry breeding has been gaining interest in recent years. Poplar bark lipids (PBLs), which are extracted from poplar tree bark, are natural substances known to efficiently enhance the immune response. To understand the chemical makeup of PBLs and their underlying mechanism for enhancing the immune system, we extracted PBLs from poplar bark using petroleum ether and subjected these extracts to chemical analysis. To evaluate PBLs effect on the immune system mice were treated with different doses of PBL via gavage and sacrificed 4 weeks later. PBLs were shown to be rich in vitamin E, unsaturated fatty acids, and other immune-potentiating compounds. Treatment with PBLs increased the spleen index and stimulated spleen and thymus development. In addition, PBLs increased the number of CD3CD4 cells in the peripheral blood and the ratio of CD4/CD8 cells while decreasing the number of CD3CD8 cells. Moreover, PBLs significantly increased IL-4 and IFN-γ levels in mouse serum and TLR4 mRNA and protein expression in the spleen. Taken together these results demonstrate that PBLs exert their immune-potentiating effects by promoting spleen and thymus development, T lymphocyte proliferation and differentiation, and immune factor expression. These immune-potentiating effects may be related to the activation of TLR4. This study provides a theoretical basis for the development of PBLs as an immune adjuvant or feed additive in the future.
近年来，人们对研究用于家畜和家禽养殖的免疫增强剂的组成和应用越来越感兴趣。从杨树树皮中提取的杨树皮脂质（PBL）是一种天然物质，已知其能有效增强免疫反应。为了了解 PBL 的化学组成及其增强免疫系统的潜在机制，我们使用石油醚从杨树皮中提取 PBL，并对这些提取物进行了化学分析。为了评估 PBL 对免疫系统的影响，我们通过灌胃给予小鼠不同剂量的 PBL，并在 4 周后处死它们。结果表明，PBL 富含维生素 E、不饱和脂肪酸和其他免疫增强化合物。PBL 处理可增加脾脏指数，并刺激脾脏和胸腺发育。此外，PBL 增加了外周血中 CD3CD4 细胞的数量和 CD4/CD8 细胞的比例，同时减少了 CD3CD8 细胞的数量。此外，PBL 还显著增加了小鼠血清中的 IL-4 和 IFN-γ 水平以及脾脏中 TLR4 mRNA 和蛋白的表达。综上所述，这些结果表明，PBL 通过促进脾脏和胸腺发育、T 淋巴细胞增殖和分化以及免疫因子表达来发挥其免疫增强作用。这些免疫增强作用可能与 TLR4 的激活有关。本研究为将来将 PBL 开发为免疫佐剂或饲料添加剂提供了理论依据。
