印楝油不同溶剂提取物对兔疥螨幼虫的离体效力试验

采用浸杀方式分别比较了印楝油石油醚、氯仿和乙酸乙酯溶剂提取物的杀螨活性,并测定了活性和得率高的溶剂提取物对兔疥螨幼虫的离体毒力,应用互补重对数模型对毒力测定数据进行分析。结果表明:印楝油石油醚、氯仿和乙酸乙酯溶剂提取物的得率分别为56.82%、25.36%和5.14%。印楝油石油醚、氯仿和乙酸乙酯溶剂提取物都具有一定杀螨活性,其中石油醚提取物活性最高,氯仿和乙酸乙酯提取物活性相近。石油醚提取物和氯仿提取物对幼螨的毒力表现为:24 h半数致死浓度(median lethal concentration,LC50)分别为1.347 7,3.917 4μL/mL,500μL/mL的半数致死时间(median lethal time,LT50)为8.404 0 h和9.643 4 h。     

印楝油氯仿提取物杀螨活性成分的分离纯化及其生物学活性

将印楝油氯仿提取物经硅胶柱层析和丙酮重结晶进行生物活性跟踪分离纯化,并运用互补重对数模型(CCL模型)分析活性化合物的离体生物活性,求出半数致死浓度(LC50)和半数致死时间(LT50).结果显示,从印楝油氯仿提取物中分离出一种白色雪花状丙酮结晶物,熔点为60～61℃,经结构鉴定为18-碳酸-3,4-呋喃二酯,其对兔疥螨幼虫的杀螨活性呈时间浓度依赖性,24 h的LC50和LC90分别为0.0818和9.842 4 g/L,7.500 g/L时的LT50和LT90分剐为15.332 4 h和24.678 4 h.这表明印楝油氯仿提取物的杀螨活性成分主要为酯类物质,对兔疥螨具有较强的杀螨活性.     

19种植物提取物的杀螨活性观察

通过体外杀虫试验观察了百部等 19种植物甲醇粗提物对兔痒螨的杀灭活性。结果表明含原植物 5 0 %的百部、橘皮、白鲜皮、苦楝皮、苦参、打破碗花花和博落回等 7种植物甲醇粗提物的水悬液均可在 4h内杀灭兔痒螨成虫 ,其中百部与博落回可在 2h内杀灭痒螨 ,其活性不低于2mg/L的阿维菌素水溶液     

3种植物对二点叶螨的生物活性

采用玻片浸渍法,对狼毒,苦参和百部根丙酮提取物对二点叶螨的生物活性进行了测定。3种植物提取物对二点叶螨都有较高的生物活性,狼毒,苦参和百部根提取物48 h的LC50分别为8.47mg/mL,0.62 mg/mL和1.51 mg/mL,对于二点叶螨,苦参提取物的活性最强,百部提取物的次之,狼毒提取物的最弱。     

四川红桔皮化学成分对家兔耳(足)螨病治疗试验

用从四川红桔皮中提取的7种化学成分,即川陈皮素(nobiletin)、蜜桔素(tangeratin),5-去甲川陈皮素(5-o-demethyl nobiletin)、4',5,7,8-四甲氧基黄酮(4',5,7,8-tetrahydroxylflavone)、麝香草酚(thymol)、β-谷甾醇(β-sitosterol)、异橙黄酮(isosi-nensetin) (依次用A,B,C,D,E,F,G代表),对兔螨进行了离体杀灭比较试验。结果以C、D、G杀螨力较强,其中又以G最强,1000倍稀释G液15 min能杀死10/10螨虫,C、D液则需4 h才能杀死10/10螨虫,对照组14 h仍有7/10螨虫存活。用G和桔皮油、辛硫磷对比杀螨,G 5～20 min、枯皮油5～30 min均可杀死10/10螨虫,而辛硫磷在6 h还有3/10活螨.以不同稀释倍数G液对5只耳螨兔进行治疗试验,结果250-500倍稀释G液治疗3 d 5/5治愈,1 000-10 000倍稀释者需7～14 d才全部治愈.进而用250-500倍稀释G液对不同养兔单位的208只耳(足)螨兔扩大治疗试验,有效率为100％,其中连续用药2～3次者,97.3％完全治愈,2.7％好转;仅治疗1次者,92％完全治愈,8％好转.用G液治疗兔螨病,无任何毒副作用.     

"喜农疥螨灵"的体外杀螨试验及对绵羊螨病的防治效果

“喜农疥螨灵”（含有效成分烯虫磷20％）的体外杀螨和防治螨病的效果观察表明：150－500mg/L浓度可在18－70min内杀死100％体外螨虫；防治羊只疥螨病最适浓度为200mg/L，补充药液浓度以400mg/L为宜；经5746只羊的春、秋两季药浴，药浴后患病羊迅速痊愈，药物残效期内未见新发病羊。     

五种中药制剂对兔螨虫的作用效果比较观察

为了筛选治疗动物螨病的中药,采用药物与离体螨虫成虫直接接触法观察其杀螨作用和药物外用于螨病患部观察其对兔螨病的疗效,比较了花椒、苦参、苦楝皮、明雄散、擦疥散五种中药制剂对兔螨虫的作用效果。通过五种中药制剂杀螨作用和对螨病疗效观察,结果表明花椒制剂杀螨效果最好,治愈螨病所需疗程最短。     

中药犬螨灵对犬蠕形螨的疗效试验

为筛选具有显著治疗犬蠕形螨的中药制剂,试验将中药小茴香、蛇床子、羊蹄根采用水煮醇沉及蒸馏等提取方法制备成中药制剂犬螨灵,并观察其对犬蠕形螨的疗效。将犬螨灵设为高、中、低3个浓度,其生药含量分别为2.0、1.0和0.5 g/mL,采用点滴法进行体外抑杀蠕形螨试验,在此基础上对12只接种蠕形螨的试验犬进行治疗试验,为验证治疗效果,对临床上已确诊的45只患有蠕形螨的病犬分3组进行临床治疗试验。结果显示,中药犬螨灵3种剂量均有较强的体外抑杀螨虫作用,高剂量组作用后4 h即可完全抑杀蠕形螨,1%伊维菌素对照组则为作用后8 h;高剂量组在治疗3周后,患处有大量新毛生长,红疹结节和皮屑消失,患处皮肤已痊愈,1%伊维菌素治疗组患犬皮肤好转,仅有少量新毛生长,不能达到痊愈标准;高、中剂量组皮肤刮取物螨虫数量平均比例及停药1个月后复发率均为0,1%伊维菌素治疗组皮肤刮取物螨虫数量平均比例及停药1月后的复发率分别为10.63%和9.17%。高剂量中药犬螨灵与1%伊维菌素两种药物联合治疗组,对临床上患病犬进行3周治疗,其虫卵平均转阴率、治愈率与平均治愈天数分别为100.00%、93.33%和19.56 d,其效果均优于中药犬螨灵与1%伊维菌素单独治疗组。结果表明,高剂量自制中药制剂犬螨灵对犬蠕形螨体外抑杀作用、接种蠕形螨试验犬与临床自然感染病例均有显著的治疗效果,优于1%伊维菌素对照组,犬螨灵作为中药杀螨虫制剂具有较好的市场开发前景。     

毛细辛提取物体外抗氧化活性研究

通过毛细辛不同溶剂提取物体外抗氧化活性研究,为进一步开发毛细辛的药用价值提供参考。用50%的乙醇回流提取毛细辛的粉末,减压浓缩过滤得到乙醇浸膏,加蒸馏水制成悬浮液,依次用等体积的石油醚,乙酸乙酯,正丁醇萃取,得到石油醚,乙酸乙酯,正丁醇和水提物。以2,6-二叔丁基对甲酚(BHT)为对照,分别采用DPPH法、Fenton法、NBT还原法和Fe²⁺螯合法测定4种提取物的抗氧化活性。结果表明,毛细辛4种溶剂提取物均有不同程度的抗氧化活性,且活性与浓度成正相关。毛细辛乙酸乙酯提取物的1,2-二苯基-2-苦苯肼自由基(DPPH·)的清除活性(IC₅₀值0.376 mg/mL),超氧阴离子自由基(O₂^-·)的清除活性(IC₅₀值0.297 mg/mL)均最强。正丁醇提取物的羟基自由基(·OH)清除活性(IC₅₀值0.776 mg/mL)为最强,水提物的金属离子螯合活性(IC₅₀值0.026 mg/mL)为最强,远超过对照BHT(0.373 mg/mL)。实验表明,毛细辛乙酸乙酯提取物,正丁醇提取物和水提物均有较强的自由基清除活性,可作为新的自由基清除剂;水提物可以作为新的金属离子螯合剂。     

复方丁香提取物软膏对犬螨虫性皮肤病防治的临床试验

为了研究复方丁香提取物软膏对犬螨虫性皮肤病的防治效果,试验选取38只螨虫等分成2组,置入培养皿中,试验组中加50%复方丁香提取物软膏溶液5 mL,对照组中加常水5 mL,进行体外杀螨试验,观察虫体运动情况。另选取患有螨虫病的犬20只,随机均分成2组,即伊维菌素对照组和试验组,进行临床治疗试验,观察临床症状积分、螨虫数及治愈情况。结果表明:在体外杀螨试验中,药物作用后试验组螨虫存活数量急剧下降,作用2 h后存活率仅为47. 3%,5 h后则无虫体存活,死亡率为100%。螨虫存活数在复方丁香提取物软膏作用1 h后显著低于对照组(X2=4. 47,P 0. 05)。试验组螨虫平均死亡时间比对照组缩短了60. 7%。在临床治疗试验中,试验组犬经过12 d治疗后,临床症状积分显著低于治疗前(P0. 05),18 d后显著低于同期伊维菌素对照组(P0. 05);试验组螨虫减少率(100%)与伊维菌素对照组(96. 5%)相当;试验组治愈率为80%,高于伊维菌素对照组。说明复方丁香提取物软膏具有较强的杀螨作用,对犬螨虫性皮肤病防治效果较好。     

Acaricidal activity of extracts of neem (Azadirachta indica) oil against the larvae of the rabbit mite Sarcoptes scabiei var. cuniculi in vitro

The acaricidal activity of the petroleum ether extract, the chloroform extract and the acetic ether extract of neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi larvae was tested in vitro. A complementary log-log (CLL) model was used to analyze the data of the toxicity tests. The results showed that at all test time points, the petroleum ether extract demonstrated the highest activity against the larvae of S. scabiei var. cuniculi, while the activities of the chloroform extract and the acetic ether extract were similar. The activities of both the petroleum ether extract and the chloroform extract against the larvae showed the relation of time and concentration dependent. The median lethal concentration (LC(50)) of the petroleum ether extract (1.3muL/mL) was about three times that of the chloroform extract (4.1muL/mL) at 24h post-treatment. At the concentrations of 500.0muL/mL, the median lethal time (LT(50)) of the petroleum ether extract and the chloroform extract was 8.4 and 9.6h, respectively.     

Acaricidal activity of extract from Eupatorium adenophorum against the Psoroptes cuniculi and Sarcoptes scabiei in vitro

The possible acaricidal activity of Eupatorium adenophorum was analyzed using extracts created by water decocting, ethanol thermal circumfluence, and steam distillation. The toxic effect of each extract was tested against Psoroptes cuniculi and Sarcoptes scabiei in vitro. Ethanol thermal circumfluence extract had strong toxicity against mites, killing all S. scabiei at 0.5 and 1.0 g/ml (w/v) concentration, while 1g/ml extract was also found to kill all P. cuniculi within a 4-h period. Similarly, 0.25, 0.5 and 1.0 g/ml concentration of extract had strong toxicity against S. scabiei, with median lethal time (LT(50)) values at 0.866, 0.785 and 0.517 h, respectively. 0.5 g/ml and 1g/ml showed strong acaricidal action against P. cuniculi; the LT(50) values were 0.93 h and 1.29 h, respectively. The median lethal concentration (LC(50)) values were 0.22 g/ml for Scabies mite and 0.64 g/ml for P. cuniculi in 1h. The results indicated that E. adenophorum contains potent acaricidal ingredients; as a first step in the potential development of novel drugs, it may provide new acaricidal compounds for the effective control of animal acariasis.     

4种中药单体物质的体外杀螨活性

以苦参碱、对叶百部碱、瑞香素、青蒿素为试验用药,采用浸杀方式测定中药单体对免疥螨幼虫的离体杀螨活性,并测定最强杀螨活性药物的半数致死浓度（Median lethal concentration,LC5。）和半数致死时间（Median lethal time,LT50）。结果显示,在药物质量浓度为10．00g／L时,苦参碱、对叶百部碱、瑞香素和青蒿素的起效时间分别为45．00、127．50、165．00、263．50min,全部死亡时间分别为1455．00、1890．00、2130．00、2280．00min。质量浓度为25．00g／L的苦参碱在试验24h时的LC50为2．86g／L;质量浓度为25．00、12．50、6．25g／L的苦参碱LT5。分别为7．54、9．85、14．55h。结果表明,4种中药单体都具有一定的体外杀螨活性,其中苦参碱的蒂螨活性最强,对叶百部碱和瑞香素次之,青蒿素杀螨活性最弱。     

Acaricidal activity of Palicourea marcgravii, a species from the Amazon forest, on cattle tick Rhipicephalus (Boophilus) microplus

Leaves of Palicourea marcgravii were extracted successively with hexane, ethyl acetate and ethanol in order to evaluate their acaricidal activity on larvae and adult stages of the cattle tick Rhipicephalus (Boophilus) microplus. The ethyl acetate extract showed the highest bioactivity of the tested extracts, which contained 0.12% monofluoroacetic acid. On engorged female, the ethyl acetate extract showed a lethal concentration 50% - LC(50)=30.08 mg ml(-1), inhibitory concentration 50% - IC(50)=5.79 mg ml(-1) and lethal time 50% - LT(50)=4.72 days; 100% reproduction was controlled at concentrations of 50 mg ml(-1) and on larvae the ethyl acetate extract showed a LC(50)=2.46 mg ml(-1). No alkaloids were detected in any of the extracts. This is the first report on the acaricidal activity of P. marcgravii extracts against R. microplus as well as the acaricidal properties of a plant species containing monofluoroacetic acid.     

Evaluation of the anthelmintic activity of Khaya senegalensis extract against gastrointestinal nematodes of sheep: in vitro and in vivo studies

The anthelmintic effect of Khaya senegalensis is described. In vitro and in vivo studies were conducted to determine possible direct anthelmintic effects of ethanolic and aqueous extracts of K. senegalensis towards different ovine gastrointestinal nematode. A larval development assay was used to investigate in vitro, the effect of aqueous and ethanolic extracts towards larvae of strongyles. The LC50 values of the effects of both the aqueous and ethanolic extracts were calculated. Another study was conducted in vivo to evaluate the therapeutic efficacy of the extracts administered orally at a dose rate of 125, 250 and 500 mg/kg of sheep harbouring naturally acquired infection of gastrointestinal nematodes. The presence of K. senegalensis extracts in the cultures decreased the viability of larvae. The LC50 of the aqueous extract (0.69 mg/ml) is not significantly different (P >0.05, t-test) from the ethanolic extract (0.51 mg/ml). The activity of the extract is concentration dependent in vivo. Sheep drenched with 500 mg/kg K. senegalensis ethanolic extract had a mean faecal egg count (FEC) reduction of 88.82%. The extract of K. senegalensis could find application in anthelmintic therapy in veterinary practice.     

In vitro acaricidal effect of tannin-rich plants against the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

The objectives of this study were to evaluate the in vitro acaricidal effects of lyophilized extracts of four tannin rich plants (Acacia pennatula, Piscidia piscipula, Leucaena leucocephala and Lysiloma latisiliquum) against diverse stages of Rhipicephalus (Boophilus) microplus, and to asses whether tannins were involved in the acaricidal effect using polyethylene glycol (PEG) to block tannins. Larval immersion (LIT) and adult immersion (AIT) tests were used to evaluate the acaricidal effect of each of the lyophilized extracts against larval and adult stages of R. microplus respectively. Larvae and adult ticks were exposed to increasing concentrations of each plant extract (0, 1200, 2400, 4800, 9600 and 19,200 μg ml(-1)) for 10 min. Larval mortality was recorded at 48 h post-incubation. Adult mortality was recorded daily over 14 days, at which point their reproductive efficiency was evaluated. PEG was added to the extracts to verify whether tannins were involved in the acaricidal effect. The effect on egg laying inhibition and larval mortality was analyzed using the GLM procedure in SAS. A Kruskal-Wallis test was used to assess the effect of PEG on LIT results. Calculation of the lethal concentration 50 (LC50) was performed using a probit analysis. All extracts reduced the viability of R. microplus larval stages (P<0.001), and viability was restored with the addition of PEG suggesting an important role of tannins in the acaricidal effect (P<0.001). The LC50 values of L. latisiliquum and P. piscipula plant extracts were 6.402 and 2.466 μg ml(-1). None of the tannin-rich plant extracts affected adult mortality (P>0.05). Lysiloma latisiliquum extract inhibited egg hatching of R. microplus (P<0.01). Tannin-rich plant extracts from A. pennatula, P. piscipula, L. leucocephala and L. latisiliquum showed potential acaricidal activity. Further in vivo studies are needed to confirm this finding.     

Ovicidal and larvicidal activity of the crude extracts from Phytolacca icosandra against Haemonchus contortus

The development of anthelmintic resistance has impacted on the success of conventional anthelmintics (AH) for the control of gastrointestinal nematodes in grazing/browsing sheep and goats. Medicinal plants from the traditional herbolary in Mexico may provide new candidates that can be explored as alternative sources of AHs for ruminants. This study evaluated the leaf extracts derived from Phytolacca icosandra against infective L(3) larvae and eggs from Haemonchus contortus collected from sheep. Three extracts of different polarities were obtained from the leaf plants using ethanol, n-hexane and dichloromethane as the solvents. The effectiveness of the in vitro AH activity of the plant extracts was evaluated using larval migration inhibition (LMI) and egg hatch (EHA) assays. For the LMI assays, the ethanolic extract of P. icosandra showed 55.4% inhibition of larval migration at 2mg/mL (p<0.05). The dichloromethane extract of P. icosandra showed 67.1% inhibition of migration at 3mg/mL (p<0.05) and a dose-dependent response with an LD(50) of 0.90 mg/mL. The n-hexane extract failed to show inhibition of larval migration at any concentration explored. In the EHA for the ethanol extract, the lowest concentration tested (0.15 mg/mL) resulted in inhibition of egg hatching greater than 72.6%. Therefore, the LD(50) could not be calculated for this extract. The LD(50) of the dichloromethane extract of P. icosandra was 0. 28 mg/mL. An egg hatch inhibition greater than 90% was observed with both the ethanolic and dichloromethane extracts when using a concentration of 0.90 mg/mL or higher. The n-hexane extract failed to show egg hatch inhibition at any concentration tested. The AH activity reported for P. icosandra could be attributable to the flavonoids, steroids, terpenoids, coumarins and/or saponins that were present in the ethanolic and dichloromethane extracts. A combination of more than one component may also explain the observed AH activity against the H. contortus life stages that were evaluated. In conclusion, the ethanolic and dichloromethane extracts of P. icosandra showed clear in vitro AH activity against the H. contortus eggs and the L(3) larvae. However, the hexanic extract of the plant leaves failed to show any in vitro AH activity.     

Anthelmintic and cytotoxic activities of extracts of Markhamia obtusifolia Sprague (Bignoniaceae)

The anthelmintic activity of Markhamia obtusifolia Sprague (Bignoniaceae) leaf extracts was evaluated against the ruminant gastrointestinal nematode parasite Trichostrongylus colubriformis (Nematoda: Strongylida) using the in vitro egg hatch test. Also, the cytotoxic activity of aqueous extracts of M. obtusifolia was evaluated in cell line cytotoxicity assays. The results indicated that the effective concentration (EC(50)) for the water extract of M. obtusifolia leaves (0.46 mg/mL; Confidence Interval [CI] 0.3-0.5mg/mL) was significantly lower than the EC(50) for the acetone extract of M. obtusifolia (0.8 mg/mL; CI 0.7-1mg/mL). Aqueous extracts were twice as potent as the acetone extracts. The EC(90) (0.2mg/mL; CI 0.1-0.02) for thiabendazole (positive control) was significantly lower than the EC(90) for the water extract of M. obtusifolia (10.7 mg/mL; CI 8.3-13.7 mg/mL). In the cytotoxicity bioassay, the lethal concentration (LC(50)) for the aqueous extract of M. obtusifolia was 0.476 mg/mL, which was relatively high (low toxicity) in comparison to the highly toxic berberine (LC(50)=9.80 μg/mL). The current study showed that M. obtusifolia plant extracts possess anthelmintic activity and are relatively non-cytotoxic, thus providing support for their use in traditional veterinary practices.     

山茱萸不同提取物降血糖作用研究

以正常小鼠和四氧嘧啶糖尿病小鼠为动物模型,分别对山茱萸乙醚提取物、乙酸乙酯提取物和乙醇提取物的降血糖作用进行研究。结果表明,山茱萸3种提取物组与模型组比较,均可显著降低四氧嘧啶糖尿病小鼠血糖水平(P0.01)。山茱萸3种提取物组间比较,乙酸乙酯提取物组的降血糖作用最明显(P0.05)。正常小鼠对照实验表明,山茱萸3种提取物对正常小鼠的血糖无明显影响(P0.05)。本试验筛选出山茱萸乙酸乙酯提取物为山茱萸的降血糖活性成分。     

柴胡水提取物抗菌作用研究

目的：研究探讨柴胡水提物的体内、外抑菌作用及其作用机理。方法：采用管碟法、试管法和小鼠腹腔注射经0.5%胃膜素增菌菌液的方法,测定其抑菌效果。结果：柴胡水提物对金黄色葡萄球菌、伤寒杆菌有显著的抑制作用;对由伤寒杆菌引起的小鼠急性腹腔感染死亡率有明显降低效果,且此效果随着药物剂量的增大有一定程度的增强。结论：柴胡水提物抑菌效能为直接作用。