Antiviral Effects of Novel Herbal Medicine KIOM-C, on Diverse Viruses

In silico studies on structural inhibition of SARS-CoV-2 main protease Mpro by major secondary metabolites of Andrographis paniculata and Cinchona officinalis

The COVID-19 infection by Novel Corona Virus (SARS-CoV-2) has become one of the largest pandemic diseases, with cumulative confirmed infections of 275,233,892 and 5,364,996 deaths to date according to World Health Organization. Due to the absence of any approved antiviral drug to treat COVID-19, its lethality is getting severe with time. The main protease of SARS-CoV-2, M^pro is considered one of the potential drug targets because of its role in processing proteins translated from viral RNA. In the present study, four of the plant metabolites, 14-deoxy-11,12-didehydroandrographolide, andrograpanin, quinine, cinchonine from two eminent medicinal plants Andrographis paniculata and Cinchona officinalis, have been evaluated against the main protease of SARS-CoV-2 through in-silico molecular docking and molecular dynamics simulation study. From the result interpretations, it is found that andrograpanin has strong binding affinities with the target protein in its active site with potential negative energies. Molecular Dynamic simulation and MMGBSA studies suggest that earlier reported N3 inhibitor and andrograpanin exhibit effective binding interactions involving identical amino acid residues with the same binding pockets of the main protease of SARS-CoV-2. Therefore, the theoretical experiment suggests that andrograpanin, could be considered the promising inhibitor against SARS-CoV-2 M^pro.

Drug repurposing for SARS-CoV-2 (COVID-19) treatment

Drug repurposing involves the process of investigating already existing drugs with an aim to use them for different therapeutic purposes than the intended one. This approach is relatively faster, less costly, and reliable in terms of safety as the drug under study is already derisked and known for its other chemistry and pharmacokinetic properties. With these benefits in mind, it is a very reliable way to undertake drug development for emerging diseases such as COVID-19 which demand immediate interventions to slow or completely stop its havoc on mankind. One of the biggest challenges that drug repurposing has is the possibility of the occurrence of new mechanisms of action between the drug ligand and some proteins in the human physiology. Drug repurposing appears to have settled in the meantime in drug development, though more studies in the future will be warranted particularly in regards to resistance.

A Herbal Mixture Formula of OCD20015-V009 Prophylactic Administration to Enhance Interferon-Mediated Antiviral Activity Against Influenza A Virus

OCD20015-V009 is an herbal mix of water-extracted Ginseng Radix, Poria (Hoelen), Rehmanniae Radix, Adenophorae Radix, Platycodi Radix, Crataegii Fructus, and Astragali Radix. In this study, its in vitro and in vivo antiviral activity and mechanisms against the influenza A virus were evaluated using a GFP-tagged influenza A virus (A/PR/8/34-GFP) to infect murine macrophages. We found that OCD20015-V009 pre-treatment substantially reduced A/PR/8/34-GFP replication. Also, OCD20015-V009 pre-treatment increased the phosphorylation of type-I IFN-related proteins TBK-1 and STAT1 and the secretion of pro-inflammatory cytokines TNF-α and IL-6 by murine macrophages. Moreover, OCD20015-V009 prophylactic administration increased IFN-stimulated genes-related 15, 20, and 56 and IFN-β mRNA in vitro. Thus, OCD20015-V009 likely modulates murine innate immune response via macrophages. This finding is potentially useful for developing prophylactics or therapeutics against the influenza A virus. Furthermore, pre-treatment with OCD20015-V009 decreased the mortality of the mice exposed to A/PR/8/34-GFP by 20% compared to that in the untreated animals. Thus, OCD20015-V009 stimulates the antiviral response in murine macrophages and mice to viral infections. Additionally, we identified chlorogenic acid and ginsenoside Rd as the antiviral components in OCD20015-V009. Further investigations are needed to elucidate the protective effects of active components of OCD20015-V009 against influenza A viruses.

Herbal Medication to Enhance or Modulate Viral Infections

Viral infections and their emergence continue to pose a threat to human lives. Up to the present, there are limited numbers of vaccines that effectively work and few antivirals licensed for use in clinical practice. Added to this is the increase in antiviral resistance, meaning that drugs that do work are at risk of reduced efficacy. The recent global pandemic of coronavirus 2019 has provided evidence for the risk of a preventative vaccination and effective treatment of viruses' subsequent consequences. The aim of this article is to review traditional and herbal treatments for infections, specifically addressing gastrointestinal and respiratory viral infections.

Antiviral effects and mechanisms of Yinhuapinggan granule against H1N1 influenza virus infection in RAW264.7 cells

Yinhuapinggan granule (YHPG), a modified prescription based on Ma-Huang-Tang (MHT), is used in traditional Chinese medicine (TCM) to treat influenza, cough, and viral pneumonia. In this study, we investigated the antiviral effects of YHPG by means of pre-, post-, and co-treatment, and its underlying mechanisms on regulating the levels of inflammatory-related cytokines, modulating the mRNA expressions of interferon-stimulated genes in influenza virus-infected murine macrophage cells (RAW264.7), and evaluating the protein expressions of key effectors in the Type I IFN and pattern recognition receptor (PRRs) signaling pathways. The results showed that YHPG markedly inhibited influenza virus (IFV) replication in pre-, post- and co-treatment assay, especially in post-treatment assay. Antiviral mechanisms studies revealed that YHPG (500 and 250 μg/mL) significantly up-regulated levels of IFN-β, IFN-stimulated genes (Mx-1, ISG-15 and ISG-56) compared with the IFV control group, while the levels of IL-6 and TNF-α were significantly down-regulated. Furthermore, western blot analysis results revealed that the protein expressions of the phosphorylated forms of TBK1, IRF3, ERK1/2, P38 MAPK and NF-κB p65 were significantly down-regulated in RAW264.7 cells with the YHPG (500 and 250 μg/mL) treatment, while the expression of the phosphorylated form of STAT1 was significantly enhanced. Based on these results, YHPG had antiviral effects in IFV-infected RAW264.7 cells, which might be associated with regulation of the inflammatory cytokines production, evaluation of the levels of IFN-stimulated genes, and modulation of the protein expressions of key effectors in the Type I IFN and PRRs signaling pathways.

Matrix Metalloproteinases: A challenging paradigm of cancer management

Matrix metalloproteinases (MMPs) are members of zinc-dependent endopeptidases implicated in a variety of physiological and pathological processes. Over the decades, MMPs have been studied for their role in cancer progression, migration, and metastasis. As a result, accumulated evidence of MMPs incriminating role has made them an attractive therapeutic target. Early generations of broad-spectrum MMP inhibitors exhibited potent inhibitory activities, which subsequently led to clinical trials. Unexpectedly, these trials failed to meet the desired goals, mainly due to the lack of efficacy, poor oral bioavailability, and toxicity. In this review, we discuss the regulatory role of MMPs in cancer progression, current strategies in targeting MMPs for cancer treatment including prodrug design and tumor imaging, and therapeutic value of MMPs as biomarkers in breast, lung, and prostate cancers.

Protective Effect of Panax notoginseng Root Water Extract against Influenza A Virus Infection by Enhancing Antiviral Interferon-Mediated Immune Responses and Natural Killer Cell Activity

Influenza is an acute respiratory illness caused by the influenza A virus, which causes economic losses and social disruption mainly by increasing hospitalization and mortality rates among the elderly and people with chronic diseases. Influenza vaccines are the most effective means of preventing seasonal influenza, but can be completely ineffective if there is an antigenic mismatch between the seasonal vaccine virus and the virus circulating in the community. In addition, influenza viruses resistant to antiviral drugs are emerging worldwide. Thus, there is an urgent need to develop new vaccines and antiviral drugs against these viruses. In this study, we conducted in vitro and in vivo analyses of the antiviral effect of Panax notoginseng root (PNR), which is used as an herbal medicine and nutritional supplement in Korea and China. We confirmed that PNR significantly prevented influenza virus infection in a concentration-dependent manner in mouse macrophages. In addition, PNR pretreatment inhibited viral protein (PB1, PB2, HA, NA, M1, PA, M2, and NP) and viral mRNA (NS1, HA, PB2, PA, NP, M1, and M2) expression. PNR pretreatment also increased the secretion of pro-inflammatory cytokines [tumor necrosis factor alpha and interleukin 6] and interferon (IFN)-beta and the phosphorylation of type-I IFN-related proteins (TANK-binding kinase 1, STAT1, and IRF3) in vitro. In mice exposed to the influenza A H1N1 virus, PNR treatment decreased mortality by 90% and prevented weight loss (by approximately 10%) compared with the findings in untreated animals. In addition, splenocytes from PNR-administered mice displayed significantly enhanced natural killer (NK) cell activity against YAC-1 cells. Taking these findings together, PNR stimulates an antiviral response in murine macrophages and mice that protects against viral infection, which may be attributable to its ability to stimulate NK cell activity. Further investigations are needed to reveal the molecular mechanisms underlying the protective effects of PNR and its components against influenza virus A infection.

Eupatorium fortunei and Its Components Increase Antiviral Immune Responses against RNA Viruses

Eupatorium fortunei (EF) has long been used as herbal medicine in Korea, China, and Asian countries to treat a variety of diseases. Recent studies have reported that EF has anti-metastatic, anti-angiogenic, anti-bacterial, and anti-oxidant activities, as well as activities against malignant metastatic human cancers. The effect of EF and its components on viruses has not been reported. In the present study, the antiviral activity and mechanism of action of an aqueous extract of EF (WEF) and its components were evaluated in vitro. We found that pretreatment with WEF markedly reduced viral replication, as evaluated using a green fluorescent protein (GFP)-tagged virus (influenza A virus, Newcastle disease virus, and vesicular stomatitis virus) in murine RAW 264.7 macrophage cells. We demonstrated that WEF induces the production of type I IFN including pro-inflammatory cytokines. Additionally, we identified the active anti-viral components of WEF as quercetin, psoralen, and quercitrin. Thus, WEF and its active components are immunomodulators of the innate immune response in murine macrophages, a finding that is potentially useful to developing prophylactic or therapeutic treatments against a range of viruses.

Ethanolic Extract of Melia Fructus Has Anti-influenza A Virus Activity by Affecting Viral Entry and Viral RNA Polymerase

Meliae Fructus (MF) is the dried ripe fruit of Melia toosendan Siebold et Zuccarini, Meliaceae family. MF is widely used in traditional medicine to treat inflammation and helminthic infection and has anti-bacterial, anti-oxidant, anti-cancer, anti-inflammatory, and analgesic activities. However, potential anti-influenza properties of MF have yet to be investigated. We determined whether an ethanolic extract of MF (EMF) has anti-viral activity via an EMF pre-, co-, and post-treatment assay, using the Influenza A/PR/8/34 and H3N2 virus on Madin-Darby canine kidney (MDCK) cells. The EMF had anti-influenza virus activity in pre- and co-treated cells in a dose-dependent manner, but not in post-treated cell. EMF inhibited the activity of hemagglutinin (HA) and neuraminidase (NA) of influenza virus. EMF inhibited viral HA, nucleoprotein (NP), matrix protein 2 (M2), non-structural protein 1 (NS1), polymerase acidic protein (PA), polymerase basic protein 1 (PB1), and polymerase basic protein 2 (PB2) mRNA synthesis at 5 h post infection (hpi), however, the levels of PA, PB1, and PB2 mRNA were increased in pre- and co-EMF treated cells compared with control virus-infected and EMF post-treated cells at 18 hpi. The level of M2 protein expression was also decreased upon pre- and co-treatment with EMF. The PA protein was accumulated and localized in not only the nucleus but also the cytoplasm of virus-infected MDCK cells at 18 hpi. Pre-EMF treatment inhibited the expression of pAKT, which is induced by influenza virus infection, at the stage of virus entry. We also found that treatment of EMF up-regulated the antiviral protein Mx1, which may play a partial role in inhibiting influenza virus infection in pre- and co-EMF treated MDCK cells. In summary, these results strongly suggested that an ethanolic extract of Meliae Fructus inhibited influenza A virus infection by affecting viral entry, PA proteins of the RNA polymerase complex, and Mx1 induction and may be a potential and novel anti-influenza agent.

In vitro Anti-viral Activity of Psoraleae Semen Water Extract against Influenza A Viruses

Influenza causes respiratory infections and poses health risks to humans and animals; its effects are complicated by increasing resistance to existing anti-influenza viral agents. Therefore, novel therapeutic approaches against influenza virus infection are required. Psoraleae semen has been widely used in traditional medicine in Korea, Taiwan, China, and Japan for treating and preventing various diseases. In this study, we examined the anti-viral activities and mechanism of action of the water extract of Psoraleae semen (WPS) using RAW 264.7 and MDCK cells. We found that pre- and post-treatment with 100 μg/mL WPS markedly inhibited influenza A virus replication as assessed using a green fluorescent protein reporter virus, reduced viral protein expression (NS-1, PA, HA, PB-1, M1, and M2), and inhibited NA and HA activities. Mechanism studies revealed that WPS induced type I interferon cytokine secretion and subsequent stimulation of an anti-viral state in RAW 264.7 cells. Further, WPS exerted inhibitory effects on neuraminidase in influenza virus strains H1N1 and H3N2. Meanwhile, WPS exhibited inhibitory effects on hemagglutination in H3N2 but not in H1N1. Based on these results, WPS serves as an immunomodulator and inhibitor of influenza hemagglutinin and neuraminidase. Our results suggest that WPS is a promising source of novel anti-influenza drug candidates.