紫锥菊提取物对高寒放牧牦牛免疫功能的影响及其作用机理的研究

In recent years， Echinacea was introduced to Qinghai. Studies from laboratory animals or humans demonstrated that Echinacea angustifolia (EA) or Echinacea other species may exert immunomodulatory actions..Studies that verified immunomodulatory potential of Echinacea spp. in farm animals are limited and no information is available for grazing Yak..Validation of bioactive compounds of plant origin and their utilization can improve animal health and safety of food of animal origin.Present in vitro study was carried out to ascertain whether a standardized extract from Echinacea angustifoliach(EA) affects spontaneous and mitogen-triggered proliferation and interferon gamma (IFN-γ) secretion in peripheral blood mononuclear cells (PBMC) from dairy cows were indicated that Echinacea angustifolia (EA) may modulate bovine PBMC proliferation, and that such activity is dose- and activation-dependent,so Echinacea angustifolia may immunomodulatory actions in dairy cows..Yak is important grazing animals in Qinghai grassland, Yak industry is the foundation of the economy in qinghai region and pillar industry. According to insecuyity on the production of Yak industry that this study was performed to ascertain whether a standardized extract from Echinacea angustifolia affects proliferation in Yak's peripheral blood mononuclear cells (PBMC). PBMC from ten Yak were incubated with or without concanavalin A or pokeweed mitogen. PBMC proliferation was assessed by ELISA. Secretion of IFN-γ was stimulated by ConA. .It would providing that natural products utilized need to be tested having great opportunities to be adopted worldwide to improve grazing Yak's immunity, health and welfare and it would providing that the development of antibiotic alternatives feed additive .

近年来，天然药物紫锥菊的免疫调节作用引起了国际上医学界和兽医界的普遍关注，研究表明，紫锥菊提取物对实验动物和人具有免疫调节作用，但对家畜的免疫调节作用的研究仍然有限。尤其是紫锥菊提取物对高寒放牧牦牛免疫调节功能影响的研究至今未见报道。目前，本课题组相应研究表明紫锥菊提取物对奶牛外周血单个核细胞有增殖的效果且可诱导γ－干扰素的产生，说明紫锥菊提取物对奶牛具有免疫调节作用。牦牛是高寒草地主要的放牧家畜，牦牛业是青海地区经济的基础及支柱产业。针对牦牛业生产上存在的不安全因素，开展本研究旨在利用ELISA法测定牦牛外周血中添加紫锥菊提取物溶液刺激单个核细胞增殖效果与细胞因子，以确定紫锥菊的提取物对牦牛免疫功能的影响。为提高牦牛免疫力，增强放牧牦牛健康、保障牦牛产品的安全和开发紫锥菊提取物作为抗生素的替代品饲料添加剂提供一定的理论依据。

紫锥菊(Echinacea . purpurea)做为免疫调节剂在国际上受到普遍重视,其提取物-菊苣酸(Chicoric Acid, CA)为咖啡酸衍生物,是紫锥菊中极为重要的免疫活性成分之一，可以提高免疫细胞的吞噬作用和促进干扰素、免疫球蛋白等相关免疫分子的表达。具有抗炎、调节免疫和诱导细胞凋亡等作用。目前，高原地区引种种植的紫锥菊,仅作为观赏花卉，对活性成分未进行系统的测定分析，同时对高寒放牧条件下牦牛的免疫调节作用也未进行相关的研究。本研究首先引种种植紫锥菊，并对其有效成分进行测定，利用ELISA法，确定紫锥菊提取物对高寒放牧牦牛外周血单个核细胞（PBMC）的增殖及诱导细胞因子（γ-干扰素、白介素-6、白介素-2）产生的影响，同时在补饲日粮中添加不同浓度CA对不同阶段的牦牛进行饲喂试验。探讨CA对牦牛血清生化指标，血液免疫、抗氧化能力的影响。结果表明：高原引种紫锥菊的有效成分菊苣酸高于原产地，可有效提高不同阶段牦牛的红细胞、血红蛋白数量及白细胞、中性粒细胞的数量；同时促进脂类代谢，清洁疏通动脉，提高牦牛的携氧能力，改善牦牛体内的氧化应激状态，且对机体无毒副作用，说明菊苣酸对放牧牦牛适应高海拔、低氧的生存能力及预防炎症、增强抵抗力有显著效果，且对机体无毒副作用，可安全应用于大通牦牛的放牧生产。在体外试验中，菊苣酸通过促进放牧牦牛PBMC的增殖和诱导白介素-6，白介素-2和干扰素-γ分泌量的增加，而达到增强机体的免疫功能。对提高放牧牦牛的免疫力，预防牦牛发生炎症，增强病原抵抗力上有显著效果。本研究阐述了菊苣酸调节牦牛免疫功能的机理，初步揭示菊苣酸的免疫机制，从而增强放牧牦牛健康、保障牦牛产品的安全具有重要的理论价值和实践意义，并为紫锥菊提取物在某种程度上代替抗生素，解决对动物长期使用抗生素而产生的病菌耐药性传递问题，可作为绿色饲料添加剂在高原的研发提供有力条件，使紫锥菊能够在高原动物生产中大量推广提供理论依据。