Chronic hepatitis C virus (HCV) infection is the leading risk factor for hepatocellular carcinoma (HCC) and chronic liver disease worldwide. Green tea, in addition to being consumed as a healthy beverage, contains phenolic catechins that have been used as medicinal substances. In the present study, we illustrated that the epicatechin isomers (+)-epicatechin and (−)-epicatechin concentration-dependently inhibited HCV replication at nontoxic concentrations by using in vitro cell-based HCV replicon and JFH-1 infectious systems. In addition to significantly suppressing virus-induced cyclooxygenase-2 (COX-2) expression, our results revealed that the anti-HCV activity of the epicatechin isomers occurred through the down-regulation of COX-2. Furthermore, both the epicatechin isomers additively inhibited HCV replication in combination with either interferon-α or viral enzyme inhibitors [2′-C-methylcytidine (NM-107) or telaprevir]. They also had prominent anti-inflammatory effects by inhibiting the gene expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and inducible nitrite oxide synthase as well as the COX-2 in viral protein-expressing hepatoma Huh-7 cells. Collectively, (+)-epicatechin and (−)-epicatechin may serve as therapeutic supplements for treating HCV-related diseases.

Dengue virus (DENV) infects 400 million people worldwide annually. Infection of more than one serotype of DENV highly corresponds to dengue hemorrhagic fever and dengue shock syndrome, which are the leading causes of high mortality. Due to lack of effective vaccines and unavailable therapies against DENV, discovery of anti-DENV agents is urgently needed. We first characterize that Schisandrin A can inhibit the replication of four serotypes of DENV in a concentration- and time-dependent manner, with an effective half-maximal effective concentration 50% (EC50) value of 28.1 ± 0.42 μM against DENV serotype type 2 without significant cytotoxicity. Furthermore, schisandrin A can effectively protect mice from DENV infection by reducing disease symptoms and mortality of DENV-infected mice. We demonstrate that STAT1/2-mediated antiviral interferon responses contribute to the action of schisandrin A against DENV replication. Schisandrin A represents a potential antiviral agent to block DENV replication in vitro and in vivo. In conclusion, stimulation of STAT1/2-mediated antiviral interferon responses is a promising strategy to develop antiviral drug.

Shiunko is a traditional botanic formula (ointment) which is used clinically for the treatment of wounded skin caused by cuts, abrasions, frost or burn. The aim of this study was to evaluate the effect of Shiunko on epithelization of wounded skin. Experimental cutting wounds on the back skin of Sprague-Dawley rats were induced. Different bacterial inoculations (Pseudomonus aeruginosa and Staphylococcus aureus) and treatment (Shiunko, Povidone-iodine and saline) were arranged herein. The incidences of infection and the speed of epithelization were evaluated. We observed that the incidences of wound infection following Pseudomonas aeruginosa inoculation were lower on both the Shiunko-treated group (0%, p < 0.01) and Povidine-iodine-treated group (5%, p < 0.05), than the saline-treated group (40%). The Shiunko-treated group reported higher percentages of complete epithelization not only on the sterilized wounds (100%) but also on the contaminated wounds (90%) when compared to the saline-treated group (60% sterilized wounds, 40% and 50% contaminated wounds) on day 7 (p < 0.01). Povidone-iodine did not promote epithelization of wounded skin, whereas Shiunko did.

Hepatitis C virus (HCV) infection-induced oxidative stress is a major risk factor for the development of HCV-associated liver disease. Sulforaphane (SFN) is an antioxidant phytocompound that acts against cellular oxidative stress and tumorigenesis. However, there is little known about its anti-viral activity. In this study, we demonstrated that SFN significantly suppressed HCV protein and RNA levels in HCV replicon cells and infectious system, with an IC50 value of 5.7 ± 0.2 μM. Moreover, combination of SFN with anti-viral drugs displayed synergistic effects in the suppression of HCV replication. In addition, we found nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 induction in response to SFN and determined the signaling pathways involved in this process, including inhibition of NS3 protease activity and induction of IFN response. In contrast, the anti-viral activities were attenuated by knockdown of HO-1 with specific inhibitor (SnPP) and shRNA, suggesting that anti-HCV activity of SFN is dependent on HO-1 expression. Otherwise, SFN stimulated the phosphorylation of phosphoinositide 3-kinase (PI3K) leading Nrf2-mediated HO-1 expression against HCV replication. Overall, our results indicated that HO-1 is essential in SFN-mediated anti-HCV activity and provide new insights in the molecular mechanism of SFN in HCV replication.

MicroRNAs (miRNAs) have been reported to directly alter the virus life cycle and virus–host interactions, and so are considered promising molecules for controlling virus infection. In the present study, we observed that miR‐155 time‐dependently downregulated upon dengue virus (DENV) infection. In contrast, exogenous overexpression of miR‐155 appeared to limit viral replication in vitro, suggesting that the low levels of miR‐155 would be beneficial for DENV replication. In vivo, overexpression of miR‐155 protected ICR suckling mice from the life‐threatening effects of DENV infection and reduced virus propagation. Further investigation revealed that the anti‐DENV activity of miR‐155 was due to target Bach1, resulting in the induction of the heme oxygenase‐1 (HO‐1)‐mediated inhibition of DENV NS2B/NS3 protease activity, ultimately leading to induction of antiviral interferon responses, including interferon‐induced protein kinase R (PKR), 2′‐5′‐oligoadenylate synthetase 1 (OAS1), OAS2, and OAS3 expression, against DENV replication. Collectively, our results provide a promising new strategy to manage DENV infection by modulation of miR‐155 expression.