Antiviral Properties of R. tanguticum Nanoparticles on Herpes Simplex Virus Type I In Vitro and In Vivo.

Herpes simplex virus type 1 (HSV-1), an enveloped DNA virus, plays a key role in varieties of diseases including recurrent cold sores, keratoconjunctivitis, genital herpes and encephalitis in humans. Great efforts have been made in developing more effective and less side-effects anti-herpes simplex virus agents, including traditional Chinese herbal medicines. In the present study, we evaluated the antiviral efficacy of Rheum tanguticum nanoparticles against HSV-1 in vitro and in vivo. R. tanguticum nanoparticles could inactivate the HSV-1 virions and block the viral attachment and entry into cells. Time-of-addition assay indicated that R. tanguticum nanoparticles could interfere with the entire phase of viral replication. Besides, R. tanguticum nanoparticles showed the ability to inhibit the mRNA expression of HSV-1 immediate early gene ICP4 and early gene ICP8 as well as the expression of viral protein ICP4 and ICP8. Moreover, R. tanguticum nanoparticles have been proved to protect mice against HSV-1 induced lethality by decreasing the viral load and alleviated pathological changes in brain tissues. In conclusion, we demonstrated that R. tanguticum nanoparticles could inhibit HSV-1 infection through multiple mechanisms. These results suggest that R. tanguticum nanoparticles may have novel roles in the treatment of HSV-1 infection.

The cytokine storm of severe influenza and development of immunomodulatory therapy.

Severe influenza remains unusual in its virulence for humans. Complications or ultimately death arising from these infections are often associated with hyperinduction of proinflammatory cytokine production, which is also known as 'cytokine storm'. For this disease, it has been proposed that immunomodulatory therapy may improve the outcome, with or without the combination of antiviral agents. Here, we review the current literature on how various effectors of the immune system initiate the cytokine storm and exacerbate pathological damage in hosts. We also review some of the current immunomodulatory strategies for the treatment of cytokine storms in severe influenza, including corticosteroids, peroxisome proliferator-activated receptor agonists, sphingosine-1-phosphate receptor 1 agonists, cyclooxygenase-2 inhibitors, antioxidants, anti-tumour-necrosis factor therapy, intravenous immunoglobulin therapy, statins, arbidol, herbs, and other potential therapeutic strategies.

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.

Antiviral activity of Folium isatidis derived extracts in vitro and in vivo.

Folium isatidis is a native Chinese herbaceous plant widely used for medicinal purposes for thousands of years. However, few studies have focused on the leaves of Isatis indigotica. In this report, we isolated a series of four fractions (I-IV) from Folium isatidis and explored the antiviral activity of each tested extract. The extracts were active against a panel of RNA and DNA viruses in vitro, namely influenza A virus (IAV), coxsackie virus B3 (CVB3), respiratory syncytial virus (RSV), and adenovirus type 7 (Ad-7). Oral administration of 200 mg/kg/d of fraction III in mice exerted strong antiviral effects in viral replication, accompanied by prolonged survival rate, attenuated lung tissue damage as well as significant reductions in pulmonary virus titers and lung index. Our results provide the first biochemical evidence that Folium isatidis and its extracts could be used as potential antiviral agent in the postexposure prophylaxis for multiple viral infections.

Amelioration of influenza virus-induced reactive oxygen species formation by epigallocatechin gallate derived from green tea.

AIM: To study whether epigallocatechin gallate (EGCG), a green tea-derived polyphenol, exerted anti-influenza A virus activity in vitro and in vivo. METHODS: Madin-Darby canine kidney (MDCK) cells were tested. The antiviral activity of EGCG in the cells was determined using hemagglutination assay and qPCR. Time of addition assay was performed to determine the kinetics of inhibition of influenza A by EGCG. The level of reactive oxygen species (ROS) were determined with confocal microscopy and flow cytometry. BALB/c mice were treated with EGCG (10, 20 or 40 mg·kg(-1)·d(-1), po) for 5 d. On the 3rd d of the treatment, the mice were infected with influenza A virus. Histopathological changes, lung index and virus titers in the lungs were determined. RESULTS: Treatment of influenza A-infected MDCK cells with EGCG (1.25-100 nmol/L) inhibited influenza A replication in a concentration-dependent manner (the ED(50) value was 8.71±1.11 nmol/L). Treatment with EGCG (20 nmol/L) significantly suppressed the increased ROS level in MDCK cells following influenza A infection. In BALB/c mice infected with influenza virus, oral administration of EGCG (40 mg·kg(-1)·d(-1)) dramatically improved the survival rate, decreased the mean virus yields and mitigated viral pneumonia in the lungs, which was equivalent to oral administration of oseltamivir (40 mg·kg(-1)·d(-1)), a positive control drug. CONCLUSION: The results provide a molecular basis for development of EGCG as a novel and safe chemopreventive agent for influenza A infection.

The inhibitory effect of Rheum palmatum against coxsackievirus B3 in vitro and in vivo.

Coxsackievirus B(3)(CVB(3)) infection is the major cause of viral myocarditis, as well as dilated cardiomypathy. Rhubarb is one of the oldest and best-known traditional Chinese medicines. We initiated this study to determine the antiviral effect of an ethanol extract from the roots and rhizoma of Rheum palmatum (R. palmatum, one of the Chinese Rhubarbs), against CVB(3) in tissue culture cells and in a mouse model. The ethanol extract from R. palmatum showed significant inhibitory activity against CVB(3) on HEp-2 cells when added after infection, with IC(50) of 4 µg/ml, TI of 10. The medicated mouse serum still contained the pharmaceutical compound 24 h after intraperitoneal injection, and exhibited an antiviral effect on CVB(3)-infected cells, especially in the 0.3 and 0.5 g/kg/day treatment groups. Furthermore, the CVB(3)-infected mice were treated with the extract solution with dosages of 0.3 g/kg/day beginning 24 h post-CVB(3) exposures. The ethanol extract treated mice showed alleviated clinical signs, better survival rate, prolonged MTD and decreased viral titers compared to the virus control group. Our results indicate that the ethanol extract from R. palmatum has the anti-CVB(3) activity in vitro and in vivo and thus provides a re-evaluation of this old remedy with a broad therapeutic potential.

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

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 24 h post-HSV exposures with dosages of 3.3 g/kg/day, 6.7 g/kg/day, and 11.3 g/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 50 µg/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.

Antiviral activity of the effective monomers from Folium Isatidis against influenza virus in vivo.

In order to evaluate the anti-influenza virus activity of the effective monomer from Folium Isatidis (FI) in vivo, we established mice model with viral pneumonia and divided them into 3 different dose groups, then observed their lung indexes, pulmonary pathological changes, pulmonary virus hemagglitination titers, living time and death rates. The results showed that the monomer could reduce the pulmonary index from 2.64 to 1.93, 1.63 and 1.40 (P<0.01) and decrease the hemagglitination titer from 1.15 to 0.84, 0.70 and 0.59 (P<0.01). In addition, different groups of FI could significantly lessen the mortality rate from 100% to 30%, 25% and 15%, and prolong the living time from 5.1d to 6.5d, 8.4d and 8.9 d respectively(P<0.01). The high dose (75 mg/kg/d) has the similar effect with 100 mg/kg/d dose of virazole(P>0.05), and more effective than 200 mg/kg/d dose of antiviral liquor (P<0.05).

[Antiviral effect of epigallocatechin gallate (EGCG) on influenza A virus].

OBJECTIVE: To investigate the effects of epigallocatechin gallate (EGCG) against the influenza A virus in vitro and in vivo. METHOD: The cell culture technique was used in MDCK cells to get cell viability at different concentration of EGCG by MTT assay. Cytopathic effect (CPE) and MTT were applied to observe the protective function of EGCG and it's ingredients were administered to cells in three different ways (method I: administration before infection, method II: administration upon infection, and method II: administration after infection) to treat the infectious model in vitro. The anti-viral activity in vivo was performed on BALB/c mice, which were divided to receive EGCG. The mean survival days and the pulmonary pathological lesions of the infected mice were observed to evaluate the therapeutic efficacy of EGCG. RESULT: EGCG effectively inhibited influenza A virus in vitro. The death rate and pulmonary pathological lesions were decreased, and the mean survival days were prolonged by oral administration of EGCG in the mice infected by influenza A virus. CONCLUSION: EGCG has a strong effect against influenza A H1 N1 virus in vitro and in vivo, in a dose-dependent manner.

[Effects of Alternanthera philoxeroides Griseb against respiratory syncytial virus infection in mice].

OBJECTIVE: To investigate the effect of an oral preparation of Alternathera philoxeroides Griseb (APG) against respiratory syncytical virus (RSV) in mice. METHODS: APG preparation was administered orally in RSV-infected mice at different daily doses (2.5, 4.5 and 6.5 g/kg) to observe the therapeutic effect of the preparation. RESULTS: Distinct differences were observed between the death rate of the mice treated with APG at daily dose of 4.5 and 6.5 g/kg and that of the untreated mice with infection. After AGP treatment of the mice at 6.5 g/kg, the detection rate of the virus was 31.3% in the blood and 37.5% in the lung tissue, significantly lower than that in the untreated mice. The virus detection rate was 43.8% in the lung tissues of mice treated with APG at 4.5 g/kg, also significantly lower than that in the untreated control. APG treatment at the 3 doses resulted in different lung indices from that of the control. CONCLUSION: APG may be effective for treatment of RSV infection.

[Antiviral effect of Folium Isatidis on herpes simplex virus type I].

OBJECTIVE: To evaluate the antiviral effect of different chemical fractions isolated from Folium Isatidis on herpes simplex virus type I (HSV- I). METHOD: Anti- HSV- I effects of Folium Isatidis were investigated in Hep-2 cell by adopting MTT colorimetric assay and observing cytopathic effect (CPE). Treatment index (TI) was used to evaluate the antiviral activity of different chemical fractions from Folium Isatidis. The antiviral mechanism of Folium Isatidis was investigated by changing the different ways of drug administration. RESULT: The fractions II approximately V from Folium Isatidis inactivate HSV- I directly. None of the chemical fractions had antiviral effects of adsorption-blocking. The chemical fractions except fraction III and fraction V inhibited the biological synthesis of HSV- I. The fraction IV significantly reduce death rate of mice infected with HSV- I. CONCLUSION: The fraction IV from Folium Isatidis has powerful anti-HSV-lI effect in vitro and in vivo.