柠檬酵素对麻鸭免疫功能的影响

本试验设计旨在研究柠檬酵素对麻鸭免疫功能的增强作用。取1日龄麻鸭100只,随机分为5组,其中空白对照组饲喂玉米粉;阳性对照组在玉米粉中添加0.5%黄芪多糖;柠檬酵素组(I、Ⅱ、Ⅲ)组分别在玉米粉中添加48%、24%和12%柠檬酵素。各试验组分别于14、21和28日龄随机选取3只试验鸭采血,检测血清免疫球蛋白(IgG、IgA、IgM)含量及细胞因子(IL-2与IFN-γ)水平。结果表明,与空白对照组相比,各浓度柠檬酵素组可显著提高14日龄和21日龄麻鸭血清中IgG含量(P<0.05),24%柠檬酵素组在各时间点均可显著提高麻鸭血清中IgA含量(P<0.05)。各浓度柠檬酵素组可显著提高28日龄麻鸭血清中IL-2水平(P<0.05),提高麻鸭血清中IFN-γ水平,但无显著差异(P>0.05)。因此,柠檬酵素可通过促进血清中IgG、IgA、IgM的含量及IL-2、IFN-γ的表达量而增强麻鸭免疫功能。

Acute and subchronic toxicity as well as evaluation of safety pharmacology of modified pulsatilla granules

The present study investigated acute and subchronic toxicity and safety pharmacology of modified pulsatilla granules（MPG）to provide a basis for a comprehensive understanding of MPG toxicity.The results of acute toxicity testing showed that the median lethal dose of MPG was more than 5 000 mg kg^-1,suggesting that MPG was considered as practically non-toxic.The subchronic toxicity study for 30 days was conducted by daily oral administration at doses of 375,750 and 1 500 mg kg^-1 in Sprague-Dawley rats.The results of subchronic toxicity study showed that the body weight and relative organ weight were not significantly changed by administration of MPG.The clinical chemistry study showed that MPG could induce kidney and liver damages.In histopathological,mild lesions in liver and kidney were also observed,suggesting that the liver and kidney might be potential target organs of MPG.In the safety pharmacology study,MPG did not exhibited any side effects to rats in cardiovascular system,respiratory system and central nervous system.These results suggested that MPG could be considered safe for veterinary use.

Antibacterial Activity of 9-Octadecanoic Acid-Hexadecanoic Acid-Tetrahydrofuran-3,4-Diyl Ester from Neem Oil

The 9-octadecanoic acid-hexadecanoic acid-tetrahydrofuran-3,4-diyl ester from neem oil was investigated for antibacterial activity against three bacterial strains viz., Staphylococcus aureus ATCC No. 25923, Escherichia coli ATCC No. 44102 and Salmonella sp. ATCC No. 50 041 in vitro. The minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） values of the 9-octadecanoic acid-hexadecanoic acid-tetrahydrofuran-3,4-diyl ester were determined by using the broth microdilution dilution （BMD） method at different concentrations ranging from 20 to 0.625 mg mL-1. Its time-inhibition curve against E. coli was also tested and showed that the MIC values for the bacterial strains S. aureus, E. coli and Salmonella sp. were 20, 5 and 10 mg mL-1, respectively. Its MBC values were 20, 20 and 10 mg mL-1, respectively. The antibacterial activity of 9-octadecanoic acid-hexadecanoic acid-tetrahydrofuran-3,4-diyl ester against three strain tested showed the relationship with time and concentration.

Immunogenicity and protective efficacy of DHBV DNA vaccines expressing envelope and capsid fusion proteins in ducks delivered by attenuated Salmonella typhimurium

Duck hepatitis B virus(DHBV) shares many basic characteristics with hepatitis B virus(HBV) and is an attractive model for vaccine development. In this study, DHBV DNA vaccines were designed to express envelope and capsid fusion proteins to enhance the breadth of immune response in ducks. Attenuated Salmonella typhimurium(SL7207) was used as a carrier and adjuvant to boost the magnitude of immune response. Based on this strategy, novel DNA vaccines(SL7207-p VAX1-LC and SL7207-p VAX1-SC) were generated. Growth kinetics, genetic stabilities and relative transcription levels of the L, S and C genes introduced by these vaccine strains were measured before inoculation to guarantee safety and efficacy. The relative transcript levels of the CD4 and CD8 T genes and the antibody levels(Ig Y) in ducks receiving the vaccines were higher than those in single gene delivered groups. Additionally, the copy number of covalently closed circular DNA in hepatocytes after DHBV challenge also provided evidence that our fusion vaccines could enhance the protective efficiency against DHBV infection in ducks.

The codon-optimized capsid gene of duck circovirus can be highly expressed in yeast and self-assemble into virus-like particles

The capsid （Cap） protein, which is the only structural protein of duck circovirus （DuCV）, is the most important antigen for the development of vaccines against DuCV and the virus＇s serological diagnostic methods. In order to use yeast expression system to produce a large quantities of DuCVCap protein which is close to its natural form to display the antigen peptides perfectly, the Cap gene was optimized into the codon-optimized capsid （Opt-Cap） gene towards the preference of yeast firstly. Then, the genes of Cap and Opt-Cap were separately cloned into pPIC9K plasmid and transformed into Picha pas- toris GSl15. The strains that displayed the phenotype of Mut~ and contained multiple inserts of expression cassette were selected from those colonies. After the induction expression, the secretory type of Cap protein, which was about 43 kDa, was best expressed under 0.5% （v/v） methanol and sorbitol induction. Compared with the Cap gene, the expression level of Opt-Cap gene was much higher. What＇s more, the purified Cap protein had a good reactivity to its specific polyclone antibody and DuCV-positive serum, and it was able to self-assemble into virus-like particles （VLPs）. These VLPs, with a diameter of 15-20 nm and without a nucleic acid structure, showed a high level of similarity to DuCV particles in size and shape. All of the resultsdemonstrated that, based on the codon-optimization, it is suitable to use the P. pastoris expression system to produce DuCV VLPs on a large scale. It is the first time that a large amounts of DuCV VLPs were produced successfully in P. pastoris, which might be particularly useful for the further studies of serological diagnosis and vaccines of DuCV.

Kaempferol inhibits Pseudorabies virus replication in vitro through regulation of MAPKs and NF-κB signaling pathways

Pseudorabies virus(PRV),in the family Herpesviridae,is a pathogen of Aujeszky’s disease,which causes great economic losses to the pig industry.Recent outbreaks of Pseudorabies imply that new control measures are urgently needed.The present study shows that kaempferol is a candidate drug for controlling PRV infection,as it possesses the ability to inhibit PRV replication in a dose-dependent manner in vitro.Kaempferol at a concentration of 52.40μmol L^(-1) could decrease PRV-induced cell death by 90%.With an 50%inhibitory concentration(IC50)value of 25.57μmol L^(-1),kaempferol was more effective than acyclovir(positive control)which has an IC50 value of 54.97μmol L^(-1).A mode of action study indicated that kaempferol inhibited viral penetration and replication stages,decreasing viral loads by 4-and 30-fold,respectively.Addition of kaempferol within 16 h post infection(hpi)could significantly inhibit virus replication,and viral genome copies were decreased by almost 15-fold when kaempferol was added at 2 hpi.Kaempferol regulated the NF-κB and MAPKs signaling pathways involved in PRV infection and changed the levels of the target genes of the MAPKs(ATF-2 and c-Jun)and NF-κB(IL-1α,IL-1βand IL-2)signaling pathways.The findings of the current study suggest that kaempferol could be an alternative measure to control PRV infection.

Effects of Dangguibuxue Decoction on Immune Organs and Erythrocyte Immune in Broilers

[ Objective] To study the effects of Dangguibuxue decoction on immune organ and erythrocyte immune in broilers. [ Method] One hun- dred 1 -day-old healthy Sanhuang chickens were randomly divided into five groups, 20 in each group. They were immunized with Newcastle disease vaccine via intranasal inoculation at 7 days old. The chickens in group I, II and III drank water added the Danggguibuxue decoction at proportion of 2%, 5% and 10% （ V/V）, respectively. The chickens in the group IV drank water added Astragalus polysaccharide at proportion of 2% （V/V）. And those in the group V drank water without addition of any drug. Blood was collected via jugular vein at 14, 21 and 28 days old, respectively, and then they were dissected. The immune organ indexes, erythrocyte C3b receptor rosette rate （E-C3b RR） and erythrocyte immune complex rosette rate （E-ICRR） were measured. [ Result] The Dangguibuxue decoction had no significant effect on thymus index but significantly increased spleen index and bursa of Fabricius index. The best peripheral and humoral immunity was observed in the broilers drinking water added the Dangguibuxue decoction at proportion of 10% （ V/ V）, and its immune enhancement was better than that of Astragalus polysaccharide added at proportion of 2% （V/V）. [ Coaclusion] Dangguibuxue decoction can promote maturation of immune organs and enhance erythrocyte immune functions; thus, it can be used as immunolootentiator.

The reproductive toxicity of saponins isolated from Cortex Albiziae in female mice

Saponin frsom Cortex Albiziae(SCA) are extensively used in the clinical treatment of tumor and depression. However, SCA may cause several adverse effects, including reproductive toxicity. The present study was designed to assess the mechanism by which SCA cause reproductive toxicity in female mice. The general reproductive toxicity testing was accomplished in female Kunming mice. The animals were divided into four groups: three groups that were treated by oral gavage with 135, 270, and 540 mg·kg-1·d-1 of SCA prepared in physiological saline, respectively, and one vehicle control group that was treated with physiological saline only. The gestational toxicity tests were conducted at 540 mg·kg-1·d-1. The general reproductive toxicity results showed that the pregnancy rate of the SCA-treated group decreased with the pregnancy rate being decreased by 70% at 540 mg·kg-1·d-1. SCA elicited maternal toxicity in the ovary and the uterus, but no fetal toxicity or teratogenicity was observed. The rates of implantation in the early, middle, and late pregnancy were all decreased, with stillbirths and maternal deaths being observed. Histopathological changes showed that SCA adversely affected the ovary and the uterus. In conclusion, SCA-induced reproductive toxicity in female mice is most likely caused by its damage to the ovary and the uterus.