Zhanqiu Yang

Antiviral activity of arbidol against influenza A virus, respiratory syncytial virus, rhinovirus, coxsackie virus and adenovirus in vitro and in vivo

SummaryArbidol, ethyl-6-bromo-4-[(dimethylamino)-methyl]-5-hydroxy-1-methyl-2-[(phenylthio)methyl]-in dole-3-carboxylate hydrochloride monohydrate, is an antiviral chemical agent. In this report, we studied the antiviral activity of arbidol against a panel of human respiratory viruses, namely influenza A virus (FLU-A, A/PR/8/34 H1N1), respiratory syncytial virus (RSV), human rhinovirus type 14 (HRV 14), coxsackie virus B3 (CVB3) and adenovirus type 7 (AdV-7) in vitro in cell culture. Arbidol was found to present potent inhibitory activity against enveloped and non-enveloped RNA viruses, including FLU-A, RSV, HRV 14 and CVB3 when added before, during, or after viral infection, with 50% inhibitory concentration (IC50) ranging from 2.7 to 13.8 µg/ml. However, arbidol showed selective antiviral activity against AdV-7, a DNA virus, only when added after infection (therapeutic index (TI) = 5.5). Orally administered arbidol at 50 or 100 mg/kg/day beginning 24 h pre-virus exposure for 6 days significantly reduced mean pulmonary virus yields and the rate of mortality in mice infected with FLU-A (A/PR/8/34 H1N1). Our results suggest that arbidol has the ability to elicit protective broad-spectrum antiviral activity against a number of human pathogenic respiratory viruses.

Molecular epidemiologic analysis of group A rotaviruses in adults and children with diarrhea in Wuhan city, China, 2000-2006

SummaryTo compare epidemiologic features and genetic characteristics of group A rotaviruses causing diarrhea in children and adults, a survey was conducted in Wuhan, China, during the period of Dec. 2000–May 2006. A total of 3839 stool specimens from diarrheal patients from eight hospitals were analyzed. Winter seasonality was observed for rotavirus diarrhea in both adults and children, showing overall rotavirus-positive rates of 9.0 and 23.9%, respectively. Throughout the study period, G3 was the most frequent G serotype in both adults and children (detection rates 86.2 and 87.8%, respectively), and was mostly associated with VP4 genotype P[8], VP 6 genotype II (subgroup II), and NSP4 genotype B. G3 rotaviruses were differentiated into eight electropherotypes, among which seven types were found in specimens from both adults and children. VP7 gene sequences of G3 rotaviruses from adults and children (6 and 4 strains, respectively), detected in different years and different hospitals, showed extremely high sequence identities (99–100%) to each other and to a few G3 rotavirus strains reported in Asia. However, lower sequence identities (82–96%) were observed to most of the human and animal G3 rotaviruses reported so far, including some Chinese strains. These findings indicate that in Wuhan, China, epidemic and genetic features of rotaviruses are similar in adults and children, and it has been suggested that G3 rotaviruses that might have originated from the same rotavirus were circulating among children and adults as prevailing viruses.In this study, two rotavirus strains, G9P[8] strain L169, derived from an adult, and G4P[6] strain R479, derived from a child, were isolated and genetically analyzed. The VP7 gene of L169 belongs to a major lineage of G9 rotaviruses that are globally widespread, but is distinct from G9 rotaviruses reported previously in China. The strain R479 had a VP7 gene which was divergent from most G4 human rotaviruses and showed an unusual dual subgroup specificity, I + II. The R479 VP6 gene does not belong to the main clusters of subgroup I and II rotaviruses phylogenetically, but is related to those of the porcine rotaviruses and some unusual human rotaviruses represented by the RMC321 strain isolated in eastern India.

The effect of emodin, an anthraquinone derivative extracted from the roots of Rheum tanguticum, against herpes simplex virus in vitro and in vivo

Abstract Aim of the study Herpes simplex viruses (HSV-1 and -2) are important pathogens for humans and the discovery of novel anti-HSV drugs with low toxicity deserves great efforts. Rhubarb is one of the oldest and best-known traditional Chinese medicines. We initiated this study to test if emodin is the active ingredients from Rheum tanguticum (R. tanguticum, one of the Chinese Rhubarb) against HSV infection and to investigate its antiviral activity on HSV infection in tissue culture cells and in a mouse model. Materials and methods Emodin (3-methyl-1,6,8-trihydroxyanthraquinone) was extracted and purified from R. tanguticum (cultivated at high mountainous area in Qinghai) and the purity was determined by high performance liquid chromatography. The antiviral experiments of emodin against HSV infection were performed in vitro and in vivo. In vivo, the HSV-infected mice were orally administered with emodin beginning at 24h post-HSV exposures with dosages of 3.3g/kg/day, 6.7g/kg/day, and 11.3g/kg/day, respectively, for 7 days. Results Emodin was found to inhibit the replication of HSV-1 and HSV-2 in cell culture at the concentration of 50μg/ml with antiviral index of 2.07 and 3.53, respectively. The emodin treatment increased the survival rate of HSV-infected mice, prolonged survival time and showed higher efficacy of HSV elimination from brain, heart, liver and ganglion, compared to the viral controls. In addition, the antiviral activity of emodin was found to be equivalent to that of acyclovir in vivo. Conclusions Our results indicate that emodin has the anti-HSV activity in vitro and in vivo and is thus a promising agent in the clinical therapy of HSV infection.

Immunogenicity, safety, and protective efficacy of an inactivated SARS-associated coronavirus vaccine in rhesus monkeys

Abstract An inactivated vaccine for severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) was evaluated in rhesus monkeys. The monkeys were inoculated intramuscularly (i.m.) with 0.5, 5, 50, or 5000μg of vaccine, or PBS as control, and boosted on day 7. After 3 weeks, they were challenged with the NS-1 strain of SARS-CoV. The humoral and mucosal immune responses, clinical signs, chemical indices and viremia were monitored following the immunization and challenge. The control animals who received PBS developed atypical SAR-CoV infection after viral challenge, according to clinical, virological and pathological findings. No systematic side effects were observed in vaccinated animals post-immunization, even in at the high dose of 5000μg. The 50μg dosage of vaccine elicited SARS-CoV specific immune responses against viral infection as compared to the partial immunity elicited by 0.5 and 5μg doses. The results show that this inactivated vaccine can induce effective concomitant humoral and mucosal immunity against SARS-CoV infection, is safe in monkeys, and the vaccine maybe a good candidate for clinical trials.

In Vitro and in Vivo Studies of the Inhibitory Effects of Emodin Isolated from Polygonum cuspidatum on Coxsakievirus B4

The lack of effective therapeutics for Coxsackievirus B4 (CVB4) infection underscores the importance of finding novel antiviral compounds. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is one of the natural anthraquinone derivatives obtained from the root and rhizome of Polygonum cuspidatum. In the present study, the possibility of using emodin as a potential antiviral to treat CVB4 infection was explored in vitro and in mice. Emodin reduced CVB4 entry and replication on Hep-2 cells in a concentration- and time-dependent manner, with a 50% effective concentration (EC50) of 12.06 μM and selectivity index (SI) of 5.08, respectively. The inhibitory effect of emodin for CVB4 entry and replication was further confirmed by a quantitative real time PCR (qPCR) assay. The results further showed that the mice orally treated with different dosages of emodin displayed a dose dependent increase of survival rate, body weight and prolonged mean time of death (MTD), accompanied by significantly decreased myocardial virus titers and pathologic scores/lesions. Moreover, emodin could inhibit CVB4-induced apoptosis in vitro and in vivo. Our results indicated that emodin could be used as potential antiviral in the post-exposure prophylaxis for CVB4 infection.

The Epidemic Characteristics and Changing Trend of Hemorrhagic Fever with Renal Syndrome in Hubei Province, China

Background Hemorrhagic fever with renal syndrome (HFRS) is caused by different hantaviruses within the Bunyaviridae family. HFRS is a fulminant, infectious disease that occurs worldwide and is endemic in all 31 provinces of China. Since the first HFRS case in Hubei Province was reported in 1957, the disease has spread across the province and Hubei has become one of the seriously affected areas in China with the greatest number of reported HFRS cases in the 1980s. However, the epidemic characteristics of HFRS in Hubei are still not entirely clear and long-term, systematic investigations of this epidemic area have been very limited. Methods The spatiotemporal distribution of HFRS was investigated using data spanning the years 1980 to 2009. The annual HFRS incidence, fatality rate and seasonal incidence between 1980 and 2009 were calculated and plotted. GIS-based spatial analyses were conducted to detect the spatial distribution and seasonal pattern of HFRS. A spatial statistical analysis, using Kulldorffs spatial scan statistic, was performed to identify clustering of HFRS. Results A total of 104,467 HFRS cases were reported in Hubei Province between 1980 and 2009. Incidence of and mortality due to HFRS declined after the outbreak in 1980s and HFRS cases have been sporadic in recent years. The locations and scale of disease clusters have changed during the three decades. The seasonal epidemic pattern of HFRS was characterized by the shift from the unimodal type (autumn/winter peak) to the bimodal type. Conclusions Socioeconomic development has great influence on the transmission of hantaviruses to humans and new epidemic characteristics have emerged in Hubei Province. It is necessary to reinforce preventative measures against HFRS according to the newly-presented seasonal variation and to intensify these efforts especially in the urban areas of Hubei Province.

Characteristics of human infection with avian influenza viruses and development of new antiviral agents

Since 1997, several epizootic avian influenza viruses (AIVs) have been transmitted to humans, causing diseases and even deaths. The recent emergence of severe human infections with AIV (H7N9) in China has raised concerns about efficient interpersonal viral transmission, polygenic traits in viral pathogenicity and the management of newly emerging strains. The symptoms associated with viral infection are different in various AI strains: H5N1 and newly emerged H7N9 induce severe pneumonia and related complications in patients, while some H7 and H9 subtypes cause only conjunctivitis or mild respiratory symptoms. The virulence and tissue tropism of viruses as well as the host responses contribute to the pathogenesis of human AIV infection. Several preventive and therapeutic approaches have been proposed to combat AIV infection, including antiviral drugs such as M2 inhibitors, neuraminidase inhibitors, RNA polymerase inhibitors, attachment inhibitors and signal-transduction inhibitors etc. In this article, we summarize the recent progress in researches on the epidemiology, clinical features, pathogenicity determinants, and available or potential antivirals of AIV.

Efficacy of arbidol on lethal hantaan virus infections in suckling mice and in vitro

AbstractAim:Arbidol is an immunomodulator that was first developed in Russia. In this study, we report the antiviral activity of arbidol against Hantaan virus (HTNV) in vitro and in vivo.Methods:The antiviral activity of arbidol in vitro was determined by plaque-forming assay, ranging from 0.5 to 8 μg/mL. To investigate whether arbidol has an antiviral effect in vivo, suckling BALB/c mice infected with HTNV were treated with arbidol at 24 h before infection with a 5, 10 or 20 mg·kg−1·d−1, once per day, for 10 days. On day 12 and 28 post infection (pi), histopathological changes and viral antigen were detected. On days 4, 8, 12, and 16 pi, the viral load of target organs and serum TNF-α levels of arbidol-treated animals were determined.Results:Arbidol was found to have potent inhibitory activity against HTNV when added in vitro before or after viral infection, with a 50% inhibitory concentration (IC50) of 0.9 and 1.2 μg/mL, respectively. The 50% lethal dose (LD50) of arbidol for suckling mice was 78.42 mg·kg−1·d−1. Oral administration of arbidol increased both survival rate and mean time to death (MTD). Treatment with arbidol reduced histopathological changes, decreased viral load and viral antigen levels, and modulated the level of serum TNF-α.Conclusion:Arbidol has the ability to elicit protective antiviral activity against HTNV in vivo and in vitro.

Jiawei-Yupingfeng-Tang, a Chinese herbal formula, inhibits respiratory viral infections in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE Jiawei-Yupingfeng-Tang (JYT) is a Chinese herbal formula that is widely used to treat respiratory tract illness. However, the effect of JYT on respiratory viruses remains unknown. The influenza virus (IFV) and the human respiratory syncytial virus (HRSV) cause millions of cases of severe illness per year, and many of these illnesses develop into lethal pneumonia. The aim of this study is to evaluate whether JYT can be used to treat these infections. MATERIALS AND METHODS The effect of JYT against IFV and HRSV was tested using a plaque reduction assay in the lower respiratory tract cell line A549. The expression of ICAM-1 was determined by real-time RT-PCR and western blotting. A mouse model infected with lethal influenza developing into interstitial pneumonia was used to evaluate the effect of JYT in vivo. RESULTS JYT extract inhibited both IFV and HRSV in a dose-dependent manner when given before, during and after a viral infection. JYT was effective in blocking the entry of the virus. Furthermore, pre-treatment with JYT reduced the susceptibility of cells to the invasion of HRSV by inhibiting the expression of ICAM-1. Importantly, JYT extract increased the survival rate of lethal influenza-infected mice, prolonged the survival time and alleviated the virus-induced lung lesions, which is comparable with the effects of ribavirin treatment. CONCLUSIONS These data support JYT as an alternative modality to be used in the treatment of respiratory viral infection induced by HRSV and IFV.

Antiviral and anti-inflammatory activity of arbidol hydrochloride in influenza A (H1N1) virus infection

Aim:To investigate the effects of arbidol hydrochloride (ARB), a widely used antiviral agent, on the inflammation induced by influenza virus.Methods:MDCK cells were infected with seasonal influenza A/FM/1/47 (H1N1) or pandemic influenza A/Hubei/71/2009 (H1N1). In vitro cytotoxicity and antiviral activity of ARB was determined using MTT assay. BALB/c mice were infected with A/FM/1/47 (H1N1). Four hours later the mice were administered ARB (45, 90, and 180 mg·kg−1·d−1) or the neuraminidase inhibitor oseltamivir (22.5 mg·kg−1·d−1) via oral gavage once a day for 5 d. Body-weight, median survival time, viral titer, and lung index of the mice were measured. The levels of inflammatory cytokines were examined using real-time RT-PCR and ELISA.Results:Both H1N1 stains were equally sensitive to ARB as tested in vitro. In the infected mice, ARB (90 and 180 mg·kg−1·d−1) significantly decreased the mortality, alleviated virus-induced lung lesions and viral titers. Furthermore, ARB suppressed the levels of IL-1β, IL-6, IL-12, and TNF-α, and elevated the level of IL-10 in the bronchoalveolar lavage fluids and lung tissues. However, ARB did not significantly affect the levels of IFN-α and IFN-γ, but reduced the level of IFN-β1 in lung tissues at 5 dpi. In peritoneal macrophages challenged with A/FM/1/47 (H1N1) or poly I:C, ARB (20 μmol/L) suppressed the levels of IL-1β, IL-6, IL-12, and TNF-α, and elevated the level of IL-10. Oseltamivir produced comparable alleviation of virus-induced lung lesions with more reduction in the viral titers, but less effective modulation of the inflammatory cytokines.Conclusion:ARB efficiently inhibits both H1N1 stains and diminishes both viral replication and acute inflammation through modulating the expression of inflammatory cytokines.