Antiviral activity of Isatidis Radix derived glucosinolate isomers and their breakdown products against influenza A in vitro/ovo and mechanism of action.
- 作者列表："Nie LX","Wu YL","Dai Z","Ma SC
ETHNOPHARMACOLOGICAL RELEVANCE:Isatidis Radix, the sun-dried roots of Isatis indigotica Fortune ex Lindl., is one of the most usually used traditional Chinese medicines. For centuries, the herb has been employed in clinical practice for treatment of virus infection and inflammation. However, its active ingredients remain unclear. AIM OF THE STUDY:In the present study, the anti-influenza virus activity of epiprogoitrin, progoitrin, epigoitrin and goitrin, the Isatidis Radix derived glucosinolate isomers and their breakdown products, was firstly evaluated in vitro and in ovo and their mechanism of action was investigated. MATERIALS AND METHODS:Epiprogoitrin, progoitrin, epigoitrin and goitrin were isolated from Isatidis Radix by chiral separation. In vitro and in ovo evaluations were performed on Madin-Darby canine kidney (MDCK) cells and embryonated eggs respectively, both using protocols including prevention, treatment and virus neutralization. Hemagglutination (HA) and neuraminidase (NA) inhibition assays were performed for further understanding of the antiviral mechanism. RESULTS:Isatidis Radix derived glucosinolate isomers and their breakdown products all exhibited dose-dependent inhibition effect against influenza A virus (H1N1) without toxicity. The antiviral potency of the components was in the order of progoitrin > goitrin > epigoitrin > epiprogoitrin. The attachment of the constituents to the viral envelope conduced to the mechanism of their antiviral action without disturbing viral adsorption or budding. CONCLUSION:Taken together, these results are promising for further development of Isatidis Radix and may contribute an adjunct to pharmacotherapy for influenza virus infection.
民族药理学相关性: 板蓝根，板蓝根的晒干根，是最常用的中药之一。几个世纪以来，该草药已被用于病毒病毒感染和炎症的临床实践。然而，其活性成分仍不清楚。 研究目的: 在本研究中，表没食子苷、原 itr苷、表没食子苷和地黄苷、板蓝根来源的硫代葡萄糖苷异构体及其分解产物的抗流感病毒活性, 首次在体外和离体实验中进行评价，并对其作用机制进行了研究。 材料与方法: 采用手性分离的方法，从板蓝根中分离得到表脯叶素、原脯叶素、表脯叶素和地香素。分别采用预防、治疗和病毒中和方案对 Madin-Darby 犬肾 (MDCK) 细胞和胚胎卵进行体外和 In ovo 评价。为了进一步了解抗病毒机制，进行了血凝 (HA) 和神经氨酸酶 (NA) 抑制试验。 结果: 板蓝根来源的硫代葡萄糖苷异构体及其分解产物对甲型 H1N1 流感病毒均表现出剂量依赖性抑制作用，无毒性。各组分的抗病毒效价依次为: 原 itr> goitrin> 表 go> 表 pro。成分附着在病毒包膜上有助于其抗病毒作用的机制，而不会干扰病毒吸附或出芽。 结论: 这些研究结果对板蓝根的进一步开发具有一定的应用前景，为流感病毒感染的药物治疗提供了一种辅助手段。
METHODS:BACKGROUND:From 2015/16 through 2017/18, injectable, trivalent inactivated influenza vaccines (IIV3) and a nasal spray, tetravalent live-attenuated influenza vaccine (LAIV4) were used in parallel in Finland. To understand how well vaccination with each vaccine type protected children against influenza under real-life conditions, vaccine effectiveness in two-year-olds was estimated for all three seasons. METHODS:Each season, a nationwide register-based cohort study was conducted. The study population comprised 60,088 children in 2015/16, 60,860 children in 2016/17 and 60,345 children in 2017/18. Laboratory-confirmed influenza was the study outcome. Seasonal influenza vaccination with either LAIV4 or IIV3 was the time-dependent exposure of interest. Vaccine effectiveness was defined as 1 minus the hazard ratio comparing vaccinated with unvaccinated children. RESULTS:From 2015/16 through 2017/18, the effectiveness of LAIV4 against influenza of any virus type was estimated at 54.2% (95% confidence interval, 32.2%-69.0%), 20.3% (-12.7% to 43.6%) and 30.5% (10.9%-45.9%); the corresponding effectiveness of IIV3 was 77.2% (48.9%-89.8%), 24.5% (-29.8% to 56.1%) and -20.1% (-61.5% to 10.7%). Neither of the influenza vaccines clearly excelled in protecting children. The LAIV4 effectiveness against type B was greater than against type A and greater than the IIV3 effectiveness against type B. CONCLUSIONS:To understand how influenza vaccines could be improved, vaccine effectiveness must be analyzed by vaccine and virus type. Effectiveness estimates expressing also overall protection levels are needed to guide individual and programmatic decision-making processes. Supported by this analysis, the vaccination program in Finland now recommends LAIV4 and injectable, tetravalent inactivated influenza vaccines replacing IIV3.
METHODS::Intranasally administered influenza vaccines could be more effective than injected vaccines, since intranasal vaccination can induce virus-specific IgA antibodies in the upper respiratory tract, which is the initial site of infection. In the current study, immune responses elicited by an intranasal inactivated H5 influenza vaccine were evaluated in healthy H5 influenza virus-naive individuals. Three doses of intranasal inactivated whole-virion H5 influenza vaccine induced strong neutralizing nasal IgA and serum IgG antibodies. In addition, a mucoadhesive excipient, carboxy-vinyl polymer (CVP), had a notable impact on the induction of nasal IgA antibody responses but not serum IgG antibody responses. The nasal hemagglutinin (HA)-specific IgA antibody responses clearly correlated with mucosal neutralizing antibody responses, indicating that measurement of nasal HA-specific IgA titers could be used as a surrogate for the mucosal antibody response. Furthermore, increased numbers of plasma cells and vaccine antigen-specific helper T (Th) cells in the peripheral blood were observed after vaccination, suggesting that peripheral blood biomarkers may also be used to evaluate the intranasal vaccine-induced immune response. However, peripheral blood immune cell responses correlated with neutralizing antibody titers in serum samples but not in nasal wash samples. Thus, analysis of the peripheral blood immune response could be a surrogate for the systemic immune response to intranasal vaccination but not for the mucosal immune response. The current study suggests the clinical potential of intranasal inactivated vaccines against H5 influenza viruses and highlights the need to develop novel means to evaluate intranasal vaccine-induced mucosal immune responses. This article is protected by copyright. All rights reserved.
METHODS:BACKGROUND:Influenza is an important public health problem and existing vaccines are not completely protective. New vaccines that protect by alternative mechanisms are needed to improve efficacy of influenza vaccines. In 2015, we did a phase 1 trial of an oral influenza vaccine, VXA-A1.1. A favourable safety profile and robust immunogenicity results in that trial supported progression of the vaccine to the current phase 2 trial. The aim of this study was to evaluate efficacy of the vaccine in a human influenza challenge model. METHODS:We did a single-site, placebo-controlled and active-controlled, phase 2 study at WCCT Global, Costa Mesa, CA, USA. Eligible individuals had an initial A/California/H1N1 haemagglutination inhibition titre of less than 20 and were aged 18-49 years and in good health. Individuals were randomly assigned (2:2:1) to receive a single immunisation of either 1011 infectious units of VXA-A1.1 (a monovalent tablet vaccine) orally, a full human dose of quadrivalent inactivated influenza vaccine (IIV) via intramuscular injection, or matched placebo. Randomisation was done by computer-generated assignments with block size of five. An unmasked pharmacist provided the appropriate vaccines and placebos to the administrating nurse. Individuals receiving the treatments, investigators, and staff were all masked to group assignments. 90 days after immunisation, individuals without clinically significant symptoms or signs of influenza, an oral temperature of higher than 37·9°C, a positive result for respiratory viral shedding on a Biofire test, and any investigator-assessed contraindications were challenged intranasally with 0·5 mL wild-type A/CA/like(H1N1)pdm09 influenza virus. The primary outcomes were safety, which was assessed in all immunised participants through 365 days, and influenza-positive illness after viral challenge, which was assessed in individuals that received the viral challenge and the required number of assessments post viral challenge. This trial is registered with ClinicalTrials.gov, number NCT02918006. RESULTS:Between Aug 31, 2016, and Jan 23, 2017, 374 individuals were assessed for eligibility, of whom 179 were randomly assigned to receive either VXA-A1.1 (n=71 [one individual did not provide a diary card, thus the solicited events were assessed in 70 individuals]), IIV (n=72), or placebo (n=36). Between Dec 2, 2016, and April 26, 2017, 143 eligible individuals (58 in the VXA-A1.1 group, 54 in the IIV group, and 31 in the placebo group) were challenged with influenza virus. VXA-A1.1 was well tolerated with no serious or medically significant adverse events. The most prevalent solicited adverse events for each of the treatment groups after immunisation were headache in the VXA-A1.1 (in five [7%] of 70 participants) and placebo (in seven [19%] of 36 participants) groups and tenderness at injection site in the IIV group (in 19 [26%] of 72 participants) Influenza-positive illness after challenge was detected in 17 (29%) of 58 individuals in the VXA-A1.1 group, 19 (35%) of 54 in the IIV group, and 15 (48%) of 31 in the placebo group. INTERPRETATION:Orally administered VXA-A1.1 was well tolerated and generated protective immunity against virus shedding, similar to a licensed intramuscular IIV. These results represent a major step forward in developing a safe and effective oral influenza vaccine. FUNDING:Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, and Biomedical Advanced Research and Development Authority.