【作者】 雷宏东；

【导师】 梁剑平；

【作者基本信息】 甘肃农业大学 ， 基础兽医学， 2011， 硕士

【摘要】 鸡球虫病是一种重要的寄生虫病,分布广,感染率高,常发生在15～50日龄的雏鸡,若不能有效控制,其现场发病率可达50 %～70 %,死亡率可达20 %～30 %,严重爆发时其死亡率可高达80 %。据统计,全球养鸡业每年仅球虫病造成经济损失就达20亿英镑。目前对该病的防治仍以化学合成药及抗生素为主,但由于长期应用,易产生抗药性,且在畜产品中因药物残留而影响人类的健康。鉴于此,人们将目光转向非抗生素防治研究,如中草药。迄今为止,关于常山中单体的分离报道较为深入,而常山中生物碱提取工艺和分离方法的报道较少,并且在常山的药理作用的研究中,关于常山中生物碱对畜禽生产常见的球虫病的研究未见报道。因此,本文由此出发,对常山中生物碱开发为新型兽药的几个关键的步骤进行了一些研究,包括生物碱的提取、分离及其抗球虫活性的研究,以期为常山的工业化生产和进一步开发利用提供理论依据。主要结果如下:1常山碱含量测定方法的确定。利用常山碱在碱水条件下水解,产生邻氨基苯甲酸并将其与N-1-萘基-乙二胺盐酸盐溶液显色的原理,用紫外分光光度计比色法测定得出,常山碱提取物的总碱含量为0.327 %。2常山总生物碱提取工艺的研究。运用正交实验,分别以浸膏重量和常山碱含量作为评价指标,考察了超声波提取工艺的效果,运用SPSS 14.0软件对结果进行分析,得到优化的提取工艺如下:其提取条件为提取温度50℃,料液比1:5,提取时间1 h。3为了评价常山碱的安全性,对其进行了小白鼠的急性毒性试验。预试验初步确定用药剂量,正式试验取60只昆明种小白鼠,灌胃给药后,连续观察7天,记录小白鼠的急性毒性反应,并通过改良寇氏法计算常山碱对小白鼠的半数致死量(LD50)及LD50的95 %可信限。结果表明,给药组部分小白鼠出现中毒反应并死亡,剖检主要脏器未见病理改变,测得LD50为18.16 g/kg体重,LD50的95 %可信限为15.35 g/kg～21.49 g/kg体重。实验结果初步提示,常山碱的毒性很低,临床用药安全可靠。4在常山总生物碱抗鸡球虫病和预防鸡球虫试验中,用艾美耳球虫接种雏鸡人工引发鸡球虫病。通过不同剂量常山总生物碱防治鸡球虫病作比较,确定鸡球虫病最佳临床治疗和预防剂量,其中以20 mg/kg给药可以达到良好的治疗鸡球虫病效果,其抗球虫指数(ACI为166.31)。更多还原

【Abstract】 Avian coccidiosis is an important disease that widely spreads with a high incidence in chicken farms and is often found in chicks at 15 to 50 days old. If not effectively controlled, the prevalence of infection will be high up to 50 %～70 % with a mortality of 20 %～30 % or 80 % in severe cases. Statistical analysis indicated that the annual cost caused by the disease is estimated at￡200 million in the world. Current control of coccidosis mainly depends on synthetic chemicals or antibiotics. The durable use of the chemical drugs in the poultry industry easily leads to the resistant strains as well as the drug residues in the chickens and their products which are harmful to humans. Therefore, more and more research has shifted to non-antibiotic approaches such as medicinal herbs.So far, study on monomer abstraction from Dichroa Febrifuga deeply, discovered that until now the alkaloid extraction process and the abstraction method study report are few about Dichroa Febrifuga. It is really micro studying on the common avian coccidiosis of livestock and fowl among the numerous pharmacologicalactions of alkaloid extraction from Dichroa Febrifuga. According to the above, this article study on each committed step for new veterinary medicine, including the alkaloid extraction, abstraction and the research of anticoccdidal activity in chicken, to provide some basic theory for a large-scale industry. The main results were indicated as follows:First, the content of febrifugine.The present work presents a colorimetric method based on the principle that o-aminobenzoic acid is produced by the alkaline hydrolysis of the quinazolone structure of the febrifugine molecule, which can be determined colorimetrically by coupling with N-1-naphthyl ethylene diamine after diazotization. The content of febrifugine determinated by UV spectrophotometer and is 0.327 %.Second, research on the technical of alkaloid extraction from Dichroa Febrifuga. Using the orthogonal experimental designed method, taken the evaluating target by the extracting weight and the content of febrifugine, analyzed by software SPSS 14.0, inspected extraction process of the ultrasonic wave method . The condition is the extraction temperature 50℃, the ratio of dosage liquor 1:5, extraction time 1 h.Third, in order to evaluate the security of dichrone, the acute toxicity of dichrone was tested in mice. After preliminary experiment to determine the dosage, 60 mice were selected and divided into 6 groups. After giving medicine lavage and observing for 7 days, the acute toxic reaction was recorded and the LD50 value and 95 % confidence limit of LD50 were determined by the modified Karber’s method. The results showed that some mice appeared toxic reaction and death. No pathological change was found in the main organs by necropsy of dead mice. The LD50 was 18.16 g/kg and its 95% confidence limit was 15.35～21.49 g/kg. The results demonstrated that the dichrone has lower toxicity and safety for clinical application.Forth, in the experiments of prevention and treatment of chicken coccidiosis, we made chicken coccidiosis with Eimeria coccidia. We uesed different doses of the febrifugine to prevent and treatchicken coccidiosis, so we confirmed the best dose of clinical treatment and prevention of febrifugine. It is good therapeutic effect to treat chicken coccidian with 20 mg/kg of the febrifugine, and its anticoccidial index (ACI 166.31).更多还原