Cangma Huadu granules, a new drug with great potential to treat coronavirus and influenza infections, exert its efficacy through anti-inflammatory and immune regulation.

ETHNOPHARMACOLOGICAL RELEVANCE: Coronavirus and influenza virus infection seriously threaten human health. Cangma Huadu Granules (CMHD) is an in-hospital preparation composed of eight traditional Chinese medicines (TCM), which has been clinically used against COVID-19 in China and may be a promising candidate for the treatment of influenza. However, the role of its treatment urgently needs to be studied. AIM OF THE STUDY: To evaluate the therapeutic effects of CMHD on pneumonia induced by coronavirus (HCoV-229E) and influenza A virus (H1N1/FM1) in mice and explore its mechanism of anti-infection. MATERIALS AND METHODS: Mice were infected with HCoV-229E or H1N1/FM1 virus through the nasal cavity. CMHD (12.1, 6.05 and 3.03 g/kg/d) or the positive control drugs were administered intragastrically. The lung index and histopathological changes were used to evaluate the therapeutic effect of CMHD. The expression of TNF-α, IL-1ß, IL-6 and IL-4 in Serum and the proportion of CD4+ and CD8+ T lymphocytes in peripheral blood were detected to evaluate the anti-inflammatory and immune regulation effects of CMHD, respectively. Furthermore, the levels of p-NF-κBp65/ NF-κB p65, which was the key targets of the NF-κB pathway was analyzed. RESULTS: In HCoV-229E-induced pneumonia, the lung index was markedly reduced, and lung pathology was improved in mice that treated with CMHD (12.1, 6.05 g/kg/d). Meanwhile, the expression of TNF-α, IL-6 were obviously inhibited, but the expression of IL-4 was significantly increased in CMHD groups. Compared with the model group, CMHD could also markedly upregulate the level of CD4+ and CD8+. Furthermore, CMHD has a markedly effect on inhibit the expression of p-NF-κB p65/NF-κB p65 in the lung. In H1N1-induced pneumonia, the lung index of mice in the CMHD (12.1 g/kg/d) treatment group was lower than that in the model group, and less inflammatory infiltration could be seen in the lung pathological. Moreover, CMHD could also obviously decrease the expression of TNF-α, IL-1ß, IL-6, but significantly increase the expression of IL-4. Except for that, CMHD could also markedly downregulate the level of CD4+ and upregulate the level of CD8+ compared with the model group. In addition, CMHD has a markedly effect on inhibit the expression of p-NF-κB p65/NF-κB p65 in the lung. CONCLUSION: CMHD can significantly combats viral infections caused by HCoV-229E and H1N1, and the mechanism may be related to its multiple functions of anti-inflammatory, immunity regulating and inhibiting NF-κB signal transduction pathway.

Effect of Jinzhen granule on two coronaviruses: The novel SARS-CoV-2 and the HCoV-229E and the evidences for their mechanisms of action.

BACKGROUND: Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human coronavirus 229E (HCoV-229E) pose a huge threat to human public health, no specific treatment is available. Jinzhen granule (JZ) is a traditional eight ingredients-Chinese medicine with prominent efficacy for treating viral-induced diseases. However, little is known about the antiviral effect and mechanism of JZ against SARS-CoV-2 and HCoV-229E. PURPOSE: This study aimed to reveal the antiviral effects of JZ against SARS-CoV-2 and HCoV-229E, and to further explore the underlying mechanisms regulating the host immune response. METHODS: The chromatographic separation of JZ was performed using a Shimadzu analytical high-performance liquid chromatograph with UV detection and Alltech ELSD 2000ES. We conducted cytopathic effect (CPE) and plaque reduction assays to evaluate the antiviral effect of JZ. A lethal human angiotensin converting enzyme 2 (hACE2) transgenic mouse model of SARS-CoV-2 was established to determine the protective effect of JZ on mortality and lung virus titers. Real-time quantitative PCR assays were used to analyze the expression of proinflammatory cytokines in vitro and in vivo. Western blotting was further performed to determine the activities on regulating the nuclear factor kappa B (NF-κB)/MAPK pathway. Finally, mitochondrial membrane potential assays, flow cytometry analysis and western blotting were used to assess the anti-apoptotic potency toward HCoV-229E infection. RESULTS: The results showed that 13 chemical components were identified and five peaks were determined and quantitated (gallic acid 1.97 mg/g, baicalin 20.69 mg/g, glycyrrhizic acid 4.92 mg/g, hyodeoxycholic acid 4.86 mg/g, cholic acid 4.07 mg/g). We found that JZ exerted inhibitory potency against SARS-CoV-2 and HCoV-229E in vitro by using CPE and plaque reduction assays, and it was further found that JZ protected mice infected by SARS-CoV-2 from death and inhibited lung virus titers. JZ also significantly decreased the induction of inflammatory cytokines (IL-1α, IL-6, CCL-5 and MIP-1ß), similar to the observed in vitro effect. Moreover, JZ suppressed the release of inflammatory cytokines in vitro and it decreased the protein expression of p-p38 MAPK, p-JNK, p-NF-κB p65 and p-IκBα induced by HCoV-229E and increased the expression of IκBα. Notably, JZ significantly protected HCoV-229E-infected Huh-7 cells from mitochondrial damage and decreased apoptotic cells. The activation of the mitochondria-mediated apoptotic pathway was inhibited by JZ, as shown by the reduced expression of cleaved caspase-9, caspase-3 and p-PARP. CONCLUSIONS: In conclusion, JZ (gallic acid 1.97 mg/g, baicalin 20.69 mg/g, glycyrrhizic acid 4.92 mg/g, hyodeoxycholic acid 4.86 mg/g, cholic acid 4.07 mg/g) exhibited antiviral activities against SARS-CoV-2 and HCoV-229E by regulating the NF-κB/MAPK pathway and the mitochondria-mediated apoptotic pathway. These findings demonstrated the efficacy of JZ against CoVs and suggested JZ treatment as a novel clinical therapeutic strategy for COVID-19.

EGCG, a green tea polyphenol, inhibits human coronavirus replication in vitro.

COVID-19 pandemic results in record high deaths in many countries. Although a vaccine for SARS-CoV-2 is now available, effective antiviral drugs to treat coronavirus diseases are not available yet. Recently, EGCG, a green tea polyphenol, was reported to inhibit SARS-CoV-2 3CL-protease, however the effect of EGCG on coronavirus replication is unknown. In this report, human coronavirus HCoV-OC43 (beta coronavirus) and HCoV-229E (alpha coronavirus) were used to examine the effect of EGCG on coronavirus. EGCG treatment decreases 3CL-protease activity of HCoV-OC43 and HCoV-229E. Moreover, EGCG treatment decreased HCoV-OC43-induced cytotoxicity. Finally, we found that EGCG treatment decreased the levels of coronavirus RNA and protein in infected cell media. These results indicate that EGCG inhibits coronavirus replication.

Natural and Nature-Derived Products Targeting Human Coronaviruses.

The ongoing pandemic of severe acute respiratory syndrome (SARS), caused by the SARS-CoV-2 human coronavirus (HCoV), has brought the international scientific community before a state of emergency that needs to be addressed with intensive research for the discovery of pharmacological agents with antiviral activity. Potential antiviral natural products (NPs) have been discovered from plants of the global biodiversity, including extracts, compounds and categories of compounds with activity against several viruses of the respiratory tract such as HCoVs. However, the scarcity of natural products (NPs) and small-molecules (SMs) used as antiviral agents, especially for HCoVs, is notable. This is a review of 203 publications, which were selected using PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar, evaluates the available literature since the discovery of the first human coronavirus in the 1960s; it summarizes important aspects of structure, function, and therapeutic targeting of HCoVs as well as NPs (19 total plant extracts and 204 isolated or semi-synthesized pure compounds) with anti-HCoV activity targeting viral and non-viral proteins, while focusing on the advances on the discovery of NPs with anti-SARS-CoV-2 activity, and providing a critical perspective.

Shufeng Jiedu, a promising herbal therapy for moderate COVID-19:Antiviral and anti-inflammatory properties, pathways of bioactive compounds, and a clinical real-world pragmatic study.

BACKGROUND: Shufeng Jiedu capsules (SFJDC), a patented herbal drug composed of eight medicinal plants, is used for the treatment of different viral respiratory tract infectious diseases. Based on its antiviral, anti-inflammatory and immunoregulatory activity in acute lung injury, SFJDC might be a promising candidate for the treatment of COVID-19. PURPOSE: To evaluate the antiviral and anti-inflammatory properties and to discover the mechanism of action of SFJDC as a potential drug for the treatment of COVID-19. Furthermore, the study should determine the clinical effectiveness of SFJDC for the treatment of COVID-19. DESIGN: We analyzed the antiviral and anti-inflammatory effects of SFJDC in a HCoV-229E mouse model on lung index, virus load in the lung, the release of cytokines, and on T- and B-lymphocytes. The mechanism of action was further investigated by network analysis. Additionally, we investigated data from a clinical pragmatic real-world study for patients with confirmed COVID-19, to evaluate the clinical effect of SFJDC and to determine the best time to start the treatment. RESULTS: SFJDC significantly reduced the virus load in the lung of HCoV-229E mice (from 1109.29 ± 696.75 to 0 ± 0 copies/ml), decreased inflammatory factors IL-6, IL-10, TNF-α, and IFN-γ in the lung, and increased the amount of CD4+ and CD8+ cells in the blood compared to the model group. Network analysis revealed that SFJDC reduces the activity of NFκB via several signaling pathways. Quercetin, wogonin, and polydatin bind directly to the main protease (Mpro) of SARS-CoV-2. Clinical data showed that SFJDC, added to standard antiviral therapy (AVD), significantly reduced the clinical recovery time of COVID-19 and fatigue (from 3.55 ± 4.09 to 1.19 ± 2.28 days) as well as cough (from 5.67 ± 5.64 to 3.47 ± 3.75) days compared to AVD alone. SFJDC therapy was significantly more effective when used within the first 8 days after the onset of symptoms. CONCLUSION: SFJDC might be a promising drug for the treatment of COVID-19, but large-scale randomized, double-blinded, placebo-controlled clinical trials are needed to complement the real-world evidence. It might be beneficial to start SFJDC treatment as early as possible in suspected cases of COVID-19.

In vitro virucidal activity of Echinaforce®, an Echinacea purpurea preparation, against coronaviruses, including common cold coronavirus 229E and SARS-CoV-2.

BACKGROUND: Coronaviruses (CoVs) were long thought to only cause mild respiratory and gastrointestinal symptoms in humans but outbreaks of Middle East Respiratory Syndrome (MERS)-CoV, Severe Acute Respiratory Syndrome (SARS)-CoV-1, and the recently identified SARS-CoV-2 have cemented their zoonotic potential and their capacity to cause serious morbidity and mortality, with case fatality rates ranging from 4 to 35%. Currently, no specific prophylaxis or treatment is available for CoV infections. Therefore we investigated the virucidal and antiviral potential of Echinacea purpurea (Echinaforce®) against human coronavirus (HCoV) 229E, highly pathogenic MERS- and SARS-CoVs, as well as the newly identified SARS-CoV-2, in vitro. METHODS: To evaluate the antiviral potential of the extract, we pre-treated virus particles and cells and evaluated remaining infectivity by limited dilution. Furthermore, we exposed cells to the extract after infection to further evaluate its potential as a prophylaxis and treatment against coronaviruses. We also determined the protective effect of Echinaforce® in re-constituted nasal epithelium. RESULTS: In the current study, we found that HCoV-229E was irreversibly inactivated when exposed to Echinaforce® at 3.2 µg/ml IC50. Pre-treatment of cell lines, however, did not inhibit infection with HCoV-229E and post-infection treatment had only a marginal effect on virus propagation at 50 µg/ml. However, we did observe a protective effect in an organotypic respiratory cell culture system by exposing pre-treated respiratory epithelium to droplets of HCoV-229E, imitating a natural infection. The observed virucidal activity of Echinaforce® was not restricted to common cold coronaviruses, as both SARS-CoV-1 and MERS-CoVs were inactivated at comparable concentrations. Finally, the causative agent of COVID-19, SARS-CoV-2 was also inactivated upon treatment with 50µg/ml Echinaforce®. CONCLUSIONS: These results show that Echinaforce® is virucidal against HCoV-229E, upon direct contact and in an organotypic cell culture model. Furthermore, MERS-CoV and both SARS-CoV-1 and SARS-CoV-2 were inactivated at similar concentrations of the extract. Therefore we hypothesize that Echinacea purpurea preparations, such as Echinaforce®, could be effective as prophylactic treatment for all CoVs due to their structural similarities.

Phillyrin (KD-1) exerts anti-viral and anti-inflammatory activities against novel coronavirus (SARS-CoV-2) and human coronavirus 229E (HCoV-229E) by suppressing the nuclear factor kappa B (NF-κB) signaling pathway.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has extensively and rapidly spread in the world, causing an outbreak of acute infectious pneumonia. However, no specific antiviral drugs or vaccines can be used. Phillyrin (KD-1), a representative ingredient of Forsythia suspensa, possesses anti-inflammatory, anti-oxidant, and antiviral activities. However, little is known about the antiviral abilities and mechanism of KD-1 against SARS-CoV-2 and human coronavirus 229E (HCoV-229E). PURPOSE: The study was designed to investigate the antiviral and anti-inflammatory activities of KD-1 against the novel SARS-CoV-2 and HCoV-229E and its potential effect in regulating host immune response in vitro. METHODS: The antiviral activities of KD-1 against SARS-CoV-2 and HCoV-229E were assessed in Vero E6 cells using cytopathic effect and plaque-reduction assay. Proinflammatory cytokine expression levels upon infection with SARS-CoV-2 and HCoV-229E infection in Huh-7 cells were measured by real-time quantitative PCR assays. Western blot assay was used to determine the protein expression of nuclear factor kappa B (NF-κB) p65, p-NF-κB p65, IκBα, and p-IκBα in Huh-7 cells, which are the key targets of the NF-κB pathway. RESULTS: KD-1 could significantly inhibit SARS-CoV-2 and HCoV-229E replication in vitro. KD-1 could also markedly reduce the production of proinflammatory cytokines (TNF-α, IL-6, IL-1ß, MCP-1, and IP-10) at the mRNA levels. Moreover, KD-1 could significantly reduce the protein expression of p-NF-κB p65, NF-κB p65, and p-IκBα, while increasing the expression of IκBα in Huh-7 cells. CONCLUSIONS: KD-1 could significantly inhibit virus proliferation in vitro, the up-regulated expression of proinflammatory cytokines induced by SARS-CoV-2 and HCoV-229E by regulating the activity of the NF-кB signaling pathway. Our findings indicated that KD-1 protected against virus attack and can thus be used as a novel strategy for controlling the coronavirus disease 2019.

Antiviral effects of saikosaponins on human coronavirus 229E in vitro.

1. Saikosaponins represent a group of oleanane derivatives, usually as glucosides, that are found in a number of plant families. Saikosaponins isolated from medicinal plants such as Bupleurum spp., Heteromorpha spp. and Scrophularia scorodonia have been reported to possess various biological activities, specifically antihepatitis, antinephritis, antihepatoma, anti-inflammation, immunomodulation and antibacterial effects. 2. The aim of the present study was to examine the anticoronaviral activity of saikosaponins (A, B2, C and D) and their mode of action. Using the 2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-5-[(phenylamino) carbonyl-2H-tetrazolium hydroxide] (XTT) assay, results showed that all saikosaponins tested demonstrated antiviral activity at concentrations of 0.25-25 micromol/L, with the strongest activity being noted for saikosaponin B2 (IC50 = 1.7 +/- 0.1 micromol/L). Interestingly, both saikosaponins A (50% cellular cytotoxicity (CC50) concentration = 228.1 +/- 3.8 micromol/L; selectivity index (SI) = 26.6) and B2 (CC50 = 383.3 +/- 0.2 micromol/L; SI = 221.9) exhibited no cytotoxic effects on target cells at concentrations that achieved antiviral activity. In the time-of-addition studies, saikosaponin B2, at 6 micromol/L, significantly inhibited human coronavirus 229E infection following its addition at various time pre-infection (-4 to -1 h), coinfection (0 h) and post-infection (1-4 h). Furthermore, saikosaponin B2 also showed an inhibitory effect on viral attachment and penetration. 3. The present results indicate that saikosaponin B2 has potent anticoronaviral activity and that its mode of action possibly involves interference in the early stage of viral replication, such as absorption and penetration of the virus.