【作者】 刘玉芹；

【导师】 张秀英；

【作者基本信息】 东北农业大学 ， 基础兽医学， 2002， 硕士

【摘要】 本文从中草药对大肠杆菌的体外抑菌活性、对热敏肠毒素LT所致结扎肠袢液体蓄积的拮抗作用、对蓖麻油所致小鼠腹泻的对抗作用、对醋酸所致小鼠腹腔毛细血管通透性增高的抑制作用及对小鼠小肠推进运动的影响五个方面，系统地研究了大青叶、板蓝根、连翘、败酱草、盐酸黄连素五味中草药及其复方配伍抗仔猪大肠杆菌性腹泻的作用机理，并筛选出具有抗菌、抗肠毒素、抗炎、止泻等功效的最佳复方配伍，为筛选治疗仔猪大肠杆菌性腹泻的有效药物及研制中西复方制剂奠定了理论基础。 体外抑菌试验的结果表明：单味药中除盐酸黄连素外，大青叶、板蓝根、连翘、败酱草均显示出良好的抗菌效果，其中板蓝根的体外抗菌活性最强，其最低抑菌浓度(MIC)和最低杀菌浓度(MBC)分别为0.0016g／ml和0.0031g／ml。复方配伍中，复方—连翘+败酱草+板蓝根和复方—连翘+板蓝根+大青叶的体外抑菌效果相当，二者均优于复方—连翘+败酱草，而复方—连翘+败酱草+板蓝根+盐酸黄连素的体外抑菌效果较差。 将中草药提取液加入到细菌培养液中培养大肠杆菌，用所产的LT进行兔回肠结扎试验，大青叶组、板蓝根组、连翘组均能显著或极显著地减少培养物上清液所致结扎肠袢液体蓄积量(P＜0.05，P＜0.05，P＜0.01)，复方—连翘+败酱草+板蓝根和复方—连翘+败酱草+板蓝根+盐酸黄连素拮抗LT所致结扎肠袢的液体蓄积量的效果均极显著地优于复方—连翘+败酱草、复方—连翘+败酱草+盐酸黄连素(P＜0.01，P＜0.01)。直接将中草药提取液与LT一同注入结扎肠袢，对LT所致结扎肠袢液体蓄积量的影响结果表明，败酱草能明显减少LT所致结扎肠袢液体蓄积量(P＜0.05)，而板蓝根、大青叶、和连翘均未达到显著水平；复方—连翘+败酱草+板蓝根和复方—连翘+败酱草+板蓝根+盐酸黄连素抑制肠袢中液体蓄积量的作用较其它组稍强。连翘、败酱草、板蓝根及盐酸黄连素在抗肠毒素LT方面具有协同作用，而大青叶与其它几味药间存在拮抗作用，不宜配伍。 蓖麻油所致小鼠腹泻试验的结果显示，与对照组比较，在1-3h内，复方组—连翘+板蓝根+败酱草极显著地(P＜0.01)降低了小鼠腹泻的频率，其效果明显优于板蓝根、连翘和盐酸黄连素组(P＜0.05，P＜0.05，P＜0.05)；在同一时相内，复方组—连翘+板蓝根+败酱草小鼠的腹泻发生率较其它组有降低的趋势。在肠推进运动试验中，各药物组对小鼠小肠推进率均无明显的抑制作用。醋酸所致小鼠腹腔毛细血管通透性增高试验结果表明：与对照组相比，复方组—连翘+板蓝根+败酱草能极显著地抑制醋酸所致小鼠腹腔染料的渗出(P＜0.01)，抑制率达58.65％，败酱草和板蓝根可显著地抑制醋酸致小鼠腹腔染料的渗出(P＜0.05，P＜0.05)，抑制率分别为35.86％和35.02％。更多还原

【Abstract】 In this paper, the mechanism of action of the five Chinese herbal medicines which are Isatis leaf, Isatis root, Forsythia fruit, Patrinia and Berberine hydrochloride, and their complex prescriptions on Escherichia coli-induced diarrhea of piglet, were systematically studied from five aspects which are the bacteriostatic activity in vitro on E.coli.,the antagonism against liquid retention mediated by Escherichia coli heat-labile enterotoxin ( LT ) , the antagonistic effect on diarrhea induced by castor oil in mice , the inhibiting action on increase of capillary permeability induced by acetic acid in mouse’s abdominal cavity, the inhibiting effect on intestinal movement forward in mice ; The best complex prescription with all good activity against bacteria, antagonism against enterotoxin, anti-inflammatory action and antidiarrhea action was screened out. so these can provide theoretic bases for the selection of effective medicine to treat Escherichia coli-induced diarrhea of piglet and the development of the complex prescription composed of Chinese herbal medicine and antibacterial agents.The results of the bacteriostatic experiment in vitro indicated that out of five single medicines, except Berberine hydrochloride, Isatis leaf, Isatis root, Forsythia fruit and Patrinia, had obvious bacteriostasis .The bacteriostasis of Isatis root in vitro was the best and reached 0.0016g/ml (MIC) and 0.003 Ig/ml (MBC) respectively. Among the complex prescriptions, the bacteriostasis of Complex prescription composed of Isatis root, Forsythia fruit and Patrinia was as good as that composed of Isatis leaf, Isatis root and Forsythia fruit, and the vitro activity of these two complex prescriptions were stranger than Complex prescription composed of Forsythia fruit and Patrinia. The vitro activity of Complex prescription composed of Isatis root, Forsythia fruit, Patrinia and Berberine hydrochloride was poor.Escherichia coli was cultured in bacterial culture medium to which the extracts of the Chinese herbal medicines were added, and the cultural product LT was used to do experiment in ligated rabbit ileum. Isatis leaf, Isatis root and Forsythia fruit significantly or high significantly reduced the liquid retention caused by cultural supernatant fluid in ligated loops (P < 0.05, P < 0.05, P < 0.01). Antagonistic effects of Complex prescription composed of Isatis root, Forsythia fruit and Patrinia and Complex prescription composed of Isatis root, Forsythia fruit , Patrinia and Berberine hydrochloride on liquid retention LT-mediated in ligated loops were high significantly better than Complex prescription composed of Forsythiafruit and Patrinia and Complex prescription composed of Forsythia fruit, Patrinia and Berberine hydrochloride (P< 0.01, P< 0.01). Extracts of the Chinese herbal medicines and LT were directly injected into ligated loops together, the results of the effects on liquid retention LT-mediated in ligated loops showed that Patrinia could significantly reduce the liquid retention (P < 0.05), and Isatis leaf, Isatis root, Forsythia fruit didn’t reach significant level. The inhibiting actions of Complex prescription composed of Isatis root, Forsythia fruit and Patrinia and Complex prescription composed of Isatis root, Forsythia fruit , Patrinia and Berberine hydrochloride on liquid retention in ligated loops were stranger than others. Isatis root, Forsythia fruit , Patrinia and Berberine hydrochloride had cooperation in antagonizing against enterotoxin, and yet Isatis leaf and other several medicines were antagonistic, so they were unsuitable to compatibility of medicines.The results of the experiment in diarrhea induced by castor oil in mice showed that within l-3h, when compared with the control, Complex prescription composed of Isatis root, Forsythia fruit and Patrinia had high significantly reduced frequency of diarrhea in mice (P < 0.01), and were also better than Isatis root, Forsythia fruit and Berberine hydrochloride (P < 0.05, P < 0.05, P < 0.05). At the same time , Incidence of diarrhea in mice of C更多还原