Influence of Hypericum perforatum Extract on Piglet Infected with Porcine Respiratory and Reproductive Syndrome Virus

To study the influence of Hypericum perforatum extract （HPE） on piglets infected with porcine respiratory and reproductive syndrome virus （PRRSV）, enzyme-labeled immunosorbent assay （ELISA） and cytopathic effect （CPE） were used to determine in vitro whether HPE could induce swine pulmonary alveolar macrophages （PAMs） to secrete IFN-γ, and whether PRRSV titers in PAMs were affected by the levels of HPE-induced IFN-γ. HPE （200 mg·kg-1） was administrated by oral gavage to piglets infected with the PRRSV in vivo to observe whether HPE affected the viremia, lung viral titers, and weight gain of piglets infected with PRRSV. The results showed that HPE was capable of inducing PAMs to produce IFN-γ in a dose dependent manner and HPE pretreatment was capable of significantly reducing PRRSV viral titers in PAMs （P〈 0.01）. Administration of HPE to the PRRSV-infected animals significantly （P〈 0.05） reduced viremia over time as compared with the PRRSV-infected animals. But there was not significant decrease in lung viral titers at day 21 post-infection between the HPE- treated animals and the PRRSV-infected control piglets. There were no significant differences in weight gain over time among the HPE-treatment animals, the normal control, and the HPE control animals. The PRRSV-infected animals caused significant （P〈 0.01） growth retardation as compared with the HPE controls and the normal piglets. It suggested that HPE might be an effective novel therapeutic approach to diminish the PRRSV-induced disease in swine.

Effect of the Extract from Hypericum perforatum on Highly Pathogenic Avian Influenza Virus(HPAIV)

[Objective] The aim was to study the effects of the extract from Hypericum perforatum on highly pathogenic Avian Influenza Virus(HPAIV)in vivo.[Method] Chickens infected with H5N1 virus were treated with the extract from H.perforatum for 4 d.The virus was then detected by hemoagglutination(HA)test and reverse transcription polymerase chain reaction(RT-PCR).[Result] No H5N1 virus could be detected at the 7th d when the chickens were treated with 0.2 or 0.1 g/(kg·d)of the extract from H.perforatum.However,the virus could be detected in other chickens without the extract from HPE treatment.[Conclusion] The extract from H.perforatum might be a potential drug candidate to control infection of H5N1 subtype AIV in chickens.

Anti-Influenza A Virus Effect of Hypericum perforatum L. Extract

To study the antiviral effect of Hypericum perforatum L. extract （HPE） on influenza A virus （IAV） （H1N1） in vitro and in vivo. Cytopathic effect （CPE） and neutral red （NR） dye uptake were used to examine the antiviral effect of HPE on Madin Darby Canine Kidney （MDCK） cells which were infected with IAV in vitro HPE was effective against influenza A virus （IAV） in vitro, with a 50% effective concentration （EC50） of 40 ug/mL, The mean 50% cytotoxic concentration （CC50） in the MDCK used in these experiments was 1.5 mg/mL. Ribavirin was run in parallel with EC50 values of 5.0 ug/mL; the mean CC50 for ribavirin was 520 ug/mL. Oral gavage administrations of HPE or ribavirin to mice infected with the IAV were highly effective in preventing death, slowing the decline of arterial oxygen saturation, inhibiting lung consolidation and reducing lung virus titers. The minimum effective dose of HPE in these studies was 31.25 mg/kg/day, which was administered twice daily for 5 d beginning 4 h prior to virus exposure. Below a dosage of 2000 mg/kg/day, almost all treated mice survived, which suggests that HPE is of low toxicity. Ribavirin＇s minimum effective dose was 40 mg/kg/day with the LDso determined to be 200 mg/kg/day. Delay of the initiation of either HPE or ribavirin therapy, using approximately 1/3 LD50 dose each time, could still be protective as late as 48 h after exposure to the IAV. While both agents appeared to have similar efficacy against IAV infections, HPE was considered to be less toxic and may warrant further evaluation as a possible therapy for influenza.

贯叶连翘提取物对流感病毒感染小鼠肺中IFN-γ·TNF-α的影响

[目的]研究贯叶连翘提取物(HPE)对流感病毒感染小鼠肺组织中肿瘤坏死因子(TNF-α)、γ-干扰素(IFN-γ)等细胞因子的影响。[方法]以流感病毒滴鼻感染小鼠,分别灌胃给药(贯叶连翘提取物高剂量组100 mg/kg、低剂量组50 mg/kg和病毒唑组10 mg/kg),0.2ml/次,2次/d,5 d后摘眼球放血处死动物,摘出全肺,低温条件下制成肺匀浆,离心后取上清采用双抗体夹心ELISA法观察小鼠治疗前后肺组织中IFN-γ、TNF-α的变化。[结果]与模型对照组相比,贯叶连翘提取物流感病毒感染小鼠肺组织中TNF-α显著降低(P<0.05),IFN-γ极显著升高(P<0.01)。[结论]贯叶连翘提取物对机体抗感染免疫有一定调节作用。

贯叶金丝桃提取物对行为绝望鼠抑郁模型的抗抑郁作用

目的 对含有 0 .35 %金丝桃素的贯叶金丝桃提取物 (HPE)的抗抑郁作用进行初步研究。方法 用小鼠尾悬挂实验和大鼠强迫游泳实验模型对HPE的抗抑郁作用进行研究。结果 HPE能剂量依赖性的使小鼠尾悬挂失望时间缩短 ,在剂量为0 .18、0 .72、1.4 4g·kg-1时由 112 .4± 18.8s分别降低为 87.0± 15 .8、77.8± 2 4 .7、73.6± 2 4 .0s(P <0 .0 1) ;HPE能剂量依赖性的使大鼠强迫游泳的不动时间缩短 ,在剂量为 0 .12 86、0 .5 14 3、1.0 2 86g·kg-1的不动时间由 14 0 .4± 14 .3s分别降低为 117.0±13.5、10 5 .6± 10 .3、97.2± 38.5s(P <0 .0 1)。结论 HPE在行为绝望动物抑郁模型上有明显抗抑郁作用。

贯叶连翘提取物抗甲1型流感病毒活性的研究

目的研究贯叶连翘提取物体内外对甲1型流感病毒(IAV)活性的影响。方法以细胞存活率和抑制率为指标,采用MTT比色法检测贯叶连翘提取物体外抑制IAV活性的效应;体内实验以流感病毒滴鼻感染小鼠,分别ig给药,观察小鼠死亡率、生命延长率及小鼠病毒性肺炎的改变,判定其抗流感病毒作用。结果贯叶连翘提取物在体外随药物质量浓度的增加其细胞存活率和病毒抑制率明显升高,与病毒对照组相比均有显著性差异(P<0.01);并可降低流感病毒感染小鼠的死亡率,延长存活时间,明显减轻小鼠病毒性肺炎的症状(P<0.01)。结论贯叶连翘提取物在体内外均有良好的抗IAV活性的作用。