Efficacy of condensed tannins against larval Hymenolepis diminuta (Cestoda) in vitro and in the intermediate host Tenebrio molitor (Coleoptera) in vivo

Natural anti-parasitic compounds in plants such as condensed tannins (CT) have anthelmintic properties against a range of gastrointestinal nematodes, but for other helminths such effects are unexplored. The aim of this study was to assess the effects of CT from three different plant extracts in a model system employing the rat tapeworm, Hymenolepis diminuta, in its intermediate host, Tenebrio molitor. An in vitro study examined infectivity of H. diminuta cysticercoids (excystation success) isolated from infected beetles exposed to different concentrations of CT extracts from pine bark (PB) (Pinus sps), hazelnut pericarp (HN) (Corylus avellana) or white clover flowers (WC) (Trifolium repens), in comparison with the anthelmintic drug praziquantel (positive control). In the in vitro study, praziquantel and CT from all three plant extracts had dose-dependent inhibitory effects on cysticercoid excystation. The HN extract was most effective at inhibiting excystation, followed by PB and WC. An in vivo study was carried out on infected beetles (measured as cysticercoid establishment) fed different doses of PB, HN and praziquantel. There was a highly significant inhibitory effect of HN on cysticercoid development (p = 0.0002). Overall, CT showed a promising anti-cestodal effect against the metacestode stage of H. diminuta.     

Evaluation of Praziquantel effects on Echinostoma paraensei ultrastructure

Echinostomiasis is a food-borne, intestinal, zoonotic, snail-mediated helminthiasis caused by digenean trematodes of the family Echinostomatidae with seven species of the genus Echinostoma infecting humans or domestic and wildlife animals. Echinostoma paraensei is a peristomic 37-collar-spined echinostome belonging to the “revolutum group”.     

莫桑比克鳗鲡拟指环虫病药物防治研究

对感染拟指环虫病的莫桑比克鳗鲡（Anguilla mossambic）进行药浴处理,研究三种常用治疗药物的驱虫效果并观察鳗鲡恢复状况。结果表明,吡喹酮是寄生在莫桑比克鳗鲡的拟指环虫的有效驱虫药物,在3ppm浓度下12小时拟指环虫即被全部杀灭,且药浴后鳗鲡恢复状况显著优于其他两种药物。甲苯咪唑和敌百虫对寄生在莫桑比克鳗鲡鳃上的拟指环虫驱除效果不佳。     

A modified critical test and its use in two dose titration trials to assess efficacy of praziquantel for Anoplocephala perfoliata in equids

Aims of this study with 43 equids naturally infected with Anoplocephala perfoliata in two dose titration trials were to document (i) the usefulness of a critical test with a 48 h treatment to necropsy period, (ii) efficacy of an oral paste of 0.5-2.0 mg praziquantel/kg body weight, and (iii) when after treatment would fecal egg counts provide best estimates of the tapeworm's prevalence in a herd. All feces passed by an equid after treatment and collected in successive 12 h batches were examined for tapeworms. At necropsy, tapeworms were identified as attached to the mucosa or unattached. Tapeworms were examined with a stereoscope and identified as normal or abnormal. Fecal samples were taken for egg counts at treatment and at 6 h intervals thereafter. In 32 of 36 treated equids, efficacy was 100% and mean efficacies for 0.5, 1.0, 1.5 and 2.0 mg praziquantel/kg body weight were 85.5, 99.7, 100 and 100%, respectively. Two equids treated with 0.5 mg praziquantel/kg body weight had low efficacies (5.4 and 38.1%) and normal tapeworms were found attached in the ventral colon and in one equid also in the dorsal colon. In seven untreated equids, tapeworms were primarily in the cecum with 21.3% detached. "Major fragments" or worms without a scolex but otherwise nearly a complete worm were 20.5% of the number of intact worms; they were not included in the efficacy analysis but should be. If the two equids with low efficacy were eliminated and if the number of all tapeworms and major fragments are combined less than 0.5% were in feces within 12 h of treatment, about 20% were in the 12-24 h period, 42% in 24-36h, 24% in 36-48 h and 13.5% in the equids at necropsy. One horse passed all its tapeworms in 24 h. This 48 h test when compared with a 24 h one with no examination of feces was more efficient in use of trial animals and reduced underestimation and overestimation of efficacy. However, a protocol similar to the 48 h test but with a 24 or 36 h post-treatment period should be investigated. The mean egg count peaked 18-24 h after treatment and samples taken at that time would provide the best estimate of prevalence. The Cornell-Wisconsin centrifugal flotation technique had a specificity of 100% and at 18 and 24 h its sensitivity was 94%. A brief discussion on critical and controlled tests for assessing efficacy of an anthelmintic for A. perfoliata is presented.     

吡喹酮及其主要代谢产物在草鱼体内代谢动力学研究

[目的]研究吡喹酮及其主要代谢产物在草鱼体内的代谢动力学规律。[方法]运用高效液相色谱法(HPLC),研究淡水草鱼在单次口灌给药10 mg/kg剂量条件下,鱼体各组织中吡喹酮(PZQ)及吡喹酮一羟基代谢物(M1)的药动学差异。[结果]草鱼血浆、肠道、肝脏和肾脏内PZQ在各个时间点的药物浓度存在极显著差异(P0.01);PZQ在血浆、肠道、肝脏和肾脏的达峰时间分别为1.0、0.5、1.0和1.0 h,而药物峰浓度为0.41、0.45、0.72和0.44 mg/L,M1在血浆、肠道、肝脏和肾脏的达峰时间分别为48.0、0.5、6.0和48.0 h,而药物峰浓度为0.72、0.45、0.42和0.42 mg/g。这表明PZQ在草鱼体内吸收分布快,M1的达峰时间滞后于PZQ。二者达峰浓度相似表明M1是PZQ在草鱼体内主要代谢物。PZQ在血浆、肠道、肝脏和肾脏的消除半衰期(t_(1/2))分别为16.41、4.77、37.16和8.74 h,M1在血浆、肠道、肝脏和肾脏的消除半衰期(t_(1/2))分别为124、71、246和162 h,其消除半衰期明显比PZQ长,说明在鱼体中M1的残留时间比PZQ更长。[结论]在实际生产中,应注意对M1的检测。     

高效液相色谱法测定血浆或组织中吡喹酮,氯霉素,喹乙醇及利血平的浓度

本研究建立了测定吡喹酮、氯霉素、喹乙醇及利血平浓度的反相高效液相色谱分析方法.以ODS-C18化学键合相(5μm)作为固定相;乙醚萃取血浆中的吡喹酮,组织喹乙醇用乙酸乙酯-乙腈(3:2,V/V)抽提,虾肉氯霉素及组织利血平均用乙酸乙酯提取;甲醇-水为流动相;吡喹酮、氯霉素、喹乙醇及利血平进行紫外检测的波长分别是211、280、260及254nm,最低检出浓度分别是0.02μg/ml血浆、0.02μg/g虾肉、0.2μg/g组织及0.1μg/g组织,方法回收率分别是98.07±3.24、90.12±4.71、71.23±5.49及92.14±5.68％(平均值±标准差).这些方法简单、灵敏、专一,已用于测定猪静注及内服吡喹酮后的血浆药物浓度,对虾饲喂“虾病宝7号”(含氯霉素)后虾肉中氯霉素的残留,鸡内服中毒剂量喹乙醇的组织浓度,以及鸡内服利血平的组织浓度.     

三种药物对猪棘头虫LDH同工酶的抑制试验

根据猪棘头虫与宿主（猪）血清的ＬＤＨ同工酶的差异，用０．１％硝硫氰醚、０．１％丙硫咪唑和０．１％吡喹酮分别对猪棘头虫雄虫、雌虫和猪血清的ＬＤＨ同工酶进行了抑制试验，结果除硝硫氰醚对蛭形巨吻棘头虫雄虫、雌虫的ＬＤＨ同工酶有抑制作用外，其余的试验组与对照组均无差异。硝硫氰醚对雄虫ＬＤＨ同工酶的第２、３、４带和雌虫ＬＤＨ同工酶的第２、３带有不同程度的抑制作用，特别是雌虫ＬＤＨ同工酶的第２带最敏感，在０．１％的浓度下，该酶带被完全抑制，即没显示出来，硝硫氰醚对雄虫和雌虫ＬＤＨ同工酶的极弱带（它们各自的第１带）均无抑制作用；临床实验也显示出硝硫氰醚对治疗猪棘头虫病有一定疗效，这些表明硝硫氰醚抑制蛭形巨吻棘头虫的ＬＤＨ同工酶活力可能是该药物对该虫体的作用机理之一。     

伊维菌素吡喹酮咀嚼片含量测定方法的建立

为了建立伊维菌素吡喹酮咀嚼片同时测定两种主药含量的方法,采用十八烷基硅烷键合硅胶为填充剂,以乙腈∶水的梯度洗脱系统作为流动相,伊维菌素检测波长为245 nm,吡喹酮检测波长为210 nm。在该色谱条件下,溶剂和辅料对伊维菌素和吡喹酮出峰均无干扰,伊维菌素和吡喹酮与相邻杂质峰分离良好。伊维菌素在2～400μg/m L的浓度范围线性关系良好;吡喹酮在1～100μg/m L的浓度范围内线性关系良好。伊维菌素回收率为102.5%,吡喹酮回收率为99.4%。该方法操作简便,准确度高,重复性好,可用于伊维菌素吡喹酮咀嚼片同时测定两种主药的含量。     

透皮给药后吡喹酮在小鼠体内组织分布及药代动力学

目的研究透皮给药后吡喹酮在小鼠体内的组织分布及药代动力学。方法用200mg/mL吡喹酮透皮剂涂擦小鼠腹部后,采用高效液相色谱法检测各时间点小鼠器官(肝、心脏、脾和肾)的吡喹酮浓度,分析其在各器官药代谢动力学特点。结果透皮给药后吡喹酮在小鼠肝脏分布浓度最高,脾和肾次之,心脏的浓度最低。吡喹酮在小鼠肝脏、脾和肾脏c-t曲线,各出现两个峰值,第一个峰值4min,Cmax分别为31.78μg/mL和7.87μg/mL,第二个峰值15min,Cmax分别为27μg/mL,11.1μg/mL。小鼠心脏的c-t曲线,有一个峰值3min,Cmax3.91μg/mL。结论吡喹酮透皮给药后,在小鼠肝脏分布浓度高,达到了临床治疗的要求。     

吡喹酮、奥芬达唑对似锥低颈吸虫体外作用的初步研究

本文观察了不同浓度的吡喹酮、奥芬达唑对似锥低颈吸虫的体外作用，结果显示：吡喹酮在０．０１μｇ／ｍｌ时有杀灭作用，在０．０５μｇ／ｍｌ就有较强作用，而奥芬达唑在０．０５μｇ／ｍｌ才有杀灭作用，在０．１μｇ／ｍｌ才有较强作用。