Inhibitory effects and related molecular mechanisms of total flavonoids in Mosla chinensis Maxim against H1N1 influenza virus

Antiviral and anti-inflammatory activities of chemical constituents from twigs of Mosla chinensis Maxim

Seven undescribed compounds, including three flavones (1-3), one phenylpropanoid (19), three monoaromatic hydrocarbons (27-29), were isolated from the twigs of Mosla chinensis Maxim together with twenty-eight known compounds. The structures were characterized by HRESIMS, 1D and 2D NMR, and ECD spectroscopic techniques. Compound 20 displayed the most significant activity against A/WSN/33/2009 (H1N1) virus (IC50 = 20.47 μM) compared to the positive control oseltamivir (IC50 = 6.85 µM). Further research on the anti-influenza mechanism showed that compound 20 could bind to H1N1 virus surface antigen HA1 and inhibit the early attachment stage of the virus. Furthermore, compounds 9, 22, 23, and 25 displayed moderate inhibitory effects on the NO expression in LPS inducing Raw 264.7 cells with IC50 values of 22.78, 20.47, 27.66, and 30.14 µM, respectively.

Moslae Herba: Botany, Traditional Uses, Phytochemistry, and Pharmacology

Moslae Herba (MH) can be used for both medicine and food and has a long history of medicine. MH has the effects of sweating and relieving the exterior, removing dampness and harmonizing, and is mainly used for colds caused by damp heat in summer. It is called "Xiayue Zhi Mahuang" in China. So far, 123 chemical compounds have been isolated and identified from MH, including flavonoids, terpenoids, phenolic acids, phenylpropanoids, and other chemical compounds. Its chemical components have a wide range of pharmacological activities, including antibacterial, antiviral, anti-inflammatory, antioxidant, analgesic sedation, antipyretic, immune regulation, insecticidal, and other effects. In addition, because of its aromatic odor and health care function, MH also has development and utilization value in food, chemical, and other fields. This paper reviewed the research progress of MH in botany, traditional uses, phytochemistry, and pharmacology and provided a possible direction for further research.

Inhibitory Effects and Related Molecular Mechanisms of Huanglian-Ganjiang Combination Against H1N1 Influenza Virus

Influenza is an infectious acute respiratory disease with complications and a high mortality rate; the effective medicines for influenza therapy are limited. "Huanglian" or Coptidis Rhizoma, Coptis chinensis Franch., Ranunculaceae, and "ganjiang" or Zingiberis Rhizoma, Zingiber officinale Roscoe, Zingiberaceae, combination is clinically used for treating respiratory diseases. HPLC was applied for the quantification of berberine hydrochloride (1.101 mg/ml) and 6-gingerol (38.41 μg/ml) in the H₂O-soluble extract of the herbal formulation. In this study, the effect of "huanglian"- "ganjiang" extract on influenza virus H1N1-induced acute pulmonary inflammation was evaluated, in addition to the investigation of its anti-influenza mechanism in a mouse model. The analyzed herbal combination inhibited the expression of cytokine IL-6 and stimulated the expression of IL-2 in the serum of influenza virus-infected mice. Meanwhile, the herbal combination downregulated the gene and protein expression levels of TLR3, TLR7, MyD88, RIG-I, MAVS, TRAF3, and NF-κB p65, which are key targets of toll-like and RIG-I-like receptor signaling pathways in mice. In addition, the herbal combination could also promote the combination of intracellular autophagosomes and lysosomes in autophagosome-lysosome formation and improve impaired fusion of autophagosomes and lysosomes by influenza virus. This study suggested that the "huanglian"- "ganjiang" extract may be a candidate therapeutic strategy for the treatment of H1N1 influenza.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s43450-023-00372-z.

Antiviral Activity of Luteolin against Pseudorabies Virus In Vitro and In Vivo

Pseudorabies virus (PRV) can cause acute swine disease leading to economic losses worldwide and is a potential causative agent of viral encephalitis in humans. Although effective vaccines are available, an increasing number of variants have emerged in China, and identifying effective antiviral agents against PRV to prevent latent infection is essential. In this study, we assessed the antiviral activity of luteolin against PRV in vitro and in vivo. Luteolin was found to significantly inhibit PRV at a noncytotoxic concentration (70 μM), with an IC₅₀ of 26.24 μM and a selectivity index of 5.64. Luteolin inhibited the virus at the replication stage and decreased the expression of viral mRNA and gB protein. Luteolin reduced the apoptosis of PRV-infected cells, improved the survival rate of mice after lethal challenge, reduced the viral loads in the liver, kidney, heart, lung, and brain, reduced brain lesions, and slowed inflammation and oxidation reactions. Our results showed that luteolin has promise as a new alternative antiviral drug for PRV infection.

The crude extract from the flowers of Trollius chinensis Bunge exerts anti-influenza virus effects through modulation of the TLR3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The flowers of Trollius chinensis Bunge (Ranunculaceae) is a traditional Chinese medicine used to treat various inflammatory diseases, including upper respiratory infections, chronic tonsillitis, and pharyngitis. Recently, there has been growing research on the antiviral role of the flowers of T. chinensis Bunge. However, little is known about its anti-influenza virus effects and the underlying mechanisms.

AIM OF THE STUDY

This study aims to evaluate the therapeutic effects of the crude extract from the flowers of T. chinensis Bunge (CEFTC) on mice infected with influenza virus. We further explored its mechanism by detecting the expression of vital proteins (TLR3, TBK1, TAK1, IKKα, IRF3, and IFN-β) related to TLR3 signaling pathway.

MATERIALS AND METHODS

Mice were infected with influenza A virus (H1N1) through the nasal cavity and were intragastrically administered CEFTC at the dose of 0.2 mg/g once daily. The therapeutic effects of CEFTC were evaluated by blood cell count, lung index, spleen index, alveolar lavage fluid testing, and HE staining. Network pharmacology analysis predicted the potential signaling pathway between the flowers of T. chinensis Bunge and pneumonia. The expression of TLR3, TBK1, TAK1, IKKα, IRF3, and IFN-β in lung tissues were examined by Western blot assay. In addition, the immunofluorescence assay was applied to assess the effect of CEFTC on the distribution of IRF3 and IFN-β between nuclei and cytoplasm.

RESULTS

Compared with the infected group, the lung index was markedly reduced, and the pathological damage of the lungs was also attenuated in the CEFTC treatment group. The network pharmacology analysis indicated that the NF-κB pathway was a potential signaling pathway in the flowers of T. chinensis Bunge for the treatment of pneumonia, TLR3, IRF3, and TBK1 were crucial targets associated with pneumonia. Western blot assay demonstrated that in the high-dose virus infected group, CEFTC reduced the expression of TLR3, TAK1, TBK1, and IRF3. Furthermore, CEFTC could increase the nuclear distribution of IRF3 in alveolar epithelial cells after virus infection.

CONCLUSIONS

These results suggested that different doses of influenza virus could cause varying infection symptoms in mice. Moreover, CEFTC could exert anti-influenza virus effects by regulating the expression of TLR3, IRF3, IFN-β, TAK1, and TBK1 in the TLR3 signaling pathway.

Anti-inflammatory effects of Chaishi Tuire Granules on influenza A treatment by mediating TRAF6/MAPK14 axis

Objectives

Influenza is an infectious respiratory disease that can cause severe inflammatory reactions and threaten human life. Chaishi Tuire Granules (CSTRG), a Chinese patent medicine widely used clinically in the treatment of respiratory diseases in China, has a definite anti-inflammatory effect. However, the mechanism of CSTRG in the treatment of influenza is still unclear. This study aimed to demonstrate the anti-inflammatory effect of CSTRG on influenza A treatment and potential mechanisms.

Methods

Influenza-associated mice pneumonia model was used to explore the antiviral and anti-inflammatory effects of CSTRG in vivo. Bioinformatics analysis methods such as network pharmacology and molecular docking were carried out to predict the main active components and potential anti-inflammatory targets of CSTRG. The anti-inflammatory activity of CSTRG was determined using the lipopolysaccharide (LPS)-induced macrophages RAW264.7 cells in vitro.

Results

In vivo results showed that CSTRG can reduce the viral load in the lung tissue of infected mice, reduce the expression of TNF-α and IL-6 in lung tissue and serum, and regulate the host inflammatory response. Additionally, CSTRG treatment markedly improves the sick signs, weight loss, lung index, and lung pathological changes. Bioinformatics analysis predicted that six active compounds of CSTRG including quercetin, kaempferol, luteolin, beta-sitosterol, sitosterol, and stigmasterol could contribute to the anti-influenza activity through regulating the TRAF6/MAPK14 axis. The following research confirmed that CSTRG significantly inhibited pro-inflammatory cytokines (TNF-α and IL-6) by suppressing the expression of TRAF6 and MAPK14 in LPS-stimulated macrophages RAW264.7 cells.

Conclusion

CSTRG might inhibit the inflammatory response by mediating the TRAF6/MAPK14 axis. In the future, in-depth research is still needed to verify the mechanism of CSTRG in the treatment of influenza.

Elsholtzia ciliata (Thunb.) Hyland: A Review of Phytochemistry and Pharmacology

In this paper, the confusion of the sources of medicinal materials was briefly expounded, and the differences among the varieties were pointed out. At the same time, the chemical components and pharmacological properties of Elsholtzia ciliata (Thunb.) Hyland (E. ciliata) were reviewed. The structures of 352 compounds that have been identified are listed. These mainly include flavonoids, terpenoids, phenylpropanoids, alkaloids, and other chemical components. They have antioxidant, anti-inflammatory, antimicrobial, insecticidal, antiviral, hypolipidemic, hypoglycemic, analgesic, antiarrhythmic, antitumor, antiacetylcholinesterase, and immunoregulator activities. At present, there are many researches using essential oil and alcohol extract, and the researches on antioxidant, anti-inflammatory, anti-microbial, and other pharmacological activities are relatively mature. This paper aims to summarize the existing research, update the research progress regarding the phytochemicals and pharmacology of E. ciliate, and to provide convenience for subsequent research.

Chrysin Ameliorates Influenza Virus Infection in the Upper Airways by Repressing Virus-Induced Cell Cycle Arrest and Mitochondria-Dependent Apoptosis

Chrysin has been proven to possess antiviral properties, but the precise underlying anti-influenza mechanism and its anti-influenza efficacy in vivo are largely unclear. In this study, we investigated the involvement of chrysin in the blockade of cell cycle and apoptosis in distinct cell lines subjected to two H1N1 influenza A virus (IAV) strains, as well as its anti-IAV activity in vivo. Here, we found an early unidentified finding that chrysin strongly impeded IAV replication through a mechanism that was autonomous of innate antiviral immune activation and viral protein interaction. Surprisingly, chrysin can suppress IAV-induced cell cycle arrest in the G0/G1 phase by downregulating the expression levels of P53 and P21 while promoting Cyclin D1/CDK4 and Cyclin E1/CDK2 activation. Furthermore, chrysin dramatically inhibited the IAV-triggered mitochondrial apoptotic pathway by altering the balance of Bax/Bcl-xl and reducing caspase-9 and caspase-3 activation. Accumulated reactive oxygen species (ROS) reduction may contribute to the inhibitory role of chrysin in cell cycle arrest and apoptosis following IAV infection. Notably, chrysin preferably inhibited IAV replication in the upper respiratory tract, indicating that it might be a promising drug for restraining the spread of respiratory viruses.

Pharmacologic Activities of Plant-Derived Natural Products on Respiratory Diseases and Inflammations

Respiratory inflammation is caused by an air-mediated disease induced by polluted air, smoke, bacteria, and viruses. The COVID-19 pandemic is also a kind of respiratory disease, induced by a virus causing a serious effect on the lungs, bronchioles, and pharynges that results in oxygen deficiency. Extensive research has been conducted to find out the potent natural products that help to prevent, treat, and manage respiratory diseases. Traditionally, wider floras were reported to be used, such as Morus alba, Artemisia indica, Azadirachta indica, Calotropis gigantea, but only some of the potent compounds from some of the plants have been scientifically validated. Plant-derived natural products such as colchicine, zingerone, forsythiaside A, mangiferin, glycyrrhizin, curcumin, and many other compounds are found to have a promising effect on treating and managing respiratory inflammation. In this review, current clinically approved drugs along with the efficacy and side effects have been studied. The study also focuses on the traditional uses of medicinal plants on reducing respiratory complications and their bioactive phytoconstituents. The pharmacological evidence of lowering respiratory complications by plant-derived natural products has been critically studied with detailed mechanism and action. However, the scientific validation of such compounds requires clinical study and evidence on animal and human models to replace modern commercial medicine.

Phytochemical Profiles and their Anti-inflammatory Responses Against Influenza from Traditional Chinese Medicine or Herbs

Traditional Chinese medicine (TCM) or herbs are widely used in the prevention and treatment of viral infectious diseases. However, the underlying mechanisms of TCMs remain largely obscure due to complicated material basis and multi-target therapeutics. TCMs have been reported to display anti-influenza activity associated with immunoregulatory mechanisms by enhancing host antiinfluenza immune responses. Previous studies have helped us understand the direct harm caused by the virus itself. In this review, we have tried to summarize recent progress in TCM-based anti-influenza research on the indirect harmful immune responses caused by influenza viruses. In particular, the phytochemicals from TCMs responsible for molecular mechanisms of action belonging to different classes, including phenolic compounds, flavonoids, alkaloids and polysaccharides, have been identified and demonstrated. In addition, this review focuses on the pharmacological mechanism, e.g., inflammatory responses and the interferon (IFN) signaling pathway, which can provide a theoretical basis and approaches for TCM based anti-influenza treatment.

Investigating the active compounds and mechanism of HuaShi XuanFei formula for prevention and treatment of COVID-19 based on network pharmacology and molecular docking analysis

Traditional Chinese medicine (TCM) has exerted positive effects in controlling the COVID-19 pandemic. HuaShi XuanFei Formula (HSXFF) was developed to treat patients with mild and general COVID-19 in Zhejiang Province, China. The present study seeks to explore its potentially active compounds and pharmacological mechanisms against COVID-19 based on network pharmacology, molecular docking, and molecular dynamics (MD) simulation. All components of HSXFF were harvested from the pharmacology database of the TCMSP system. COVID-19-related targets were retrieved from using OMIM and GeneCards databases. The herb-compound-targets network was constructed by Cytoscape. The target protein–protein interaction (PPI) network, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed to discover the potential key target genes and mechanism. The main active compounds of HSXFF were docked with 3C-like (3CL) protease hydrolase and angiotensin-converting enzyme 2 (ACE2). The MD simulation confirmed the binding stability of docking results. The herbs-targets network mainly contained 52 compounds and 70 corresponding targets, including key targets such as RELA, TNF, TP53, IL6, MAPK1, CXCL8, IL-1β, and MAPK14. The GO and KEGG indicated that HSXFF may be mainly acting on the IL-17 signaling pathway, TNF signaling pathway, NF-κB signaling pathway, etc. The molecular docking results indicated that isovitexin and procyanidin B1 showed the highest affinity with 3CL and ACE2, respectively, which were confirmed by MD simulation. These findings suggested HSXFF exerted therapeutic effects involving “multi-compounds and multi-targets.” It might be working through directly inhibiting the virus, improving immune function, and reducing the inflammatory in response to anti-COVID-19. In summary, the present study would provide a valuable direction for further research of HSXFF.

Huanglian-Houpo drug combination ameliorates H1N1-induced mouse pneumonia via cytokines, antioxidant factors and TLR/MyD88/NF-κB signaling pathways

Huanglian-Houpo drug combination (HHDC) is a classical traditional Chinese medicine that has been effectively used to treat seasonal colds and flu. However, no systematic studies of the effects of HHDC on H1N1 influenza infection and the associated mechanisms have been reported. The aim of the present study was to determine the anti-H1N1 influenza effects of HHDC and explore the underlying mechanisms. A mouse model of H1N1-induced pneumonia was established and the mice were treated with HHDC (4, 8 and 16 g/kg) for 5 days after viral challenge. The antiviral effects of HHDC and the underlying mechanisms in the mice were investigated and evaluated with respect to inflammation, oxidative stress and Toll-like receptor (TLR)/myeloid differentiation factor (MyD88)/nuclear factor (NF)-κB signaling pathways. HHDC provided significant protection against weight loss and reduced the H1N1 viral load in the lungs. In addition, HHDC significantly decreased the lung index and increased the spleen and thymus indices of the H1N1-infected mice. HHDC also significantly ameliorated the histopathological changes of pneumonia, decreased serum levels of the cytokines interleukin (IL)-6, tumor necrosis factor-α and interferon-γ, and increased the serum level of IL-2. Moreover, HHDC significantly increased the levels of the antioxidant factors superoxide dismutase and glutathione, and reduced the serum level of nitric oxide. Furthermore, the mRNA and protein expression levels of TLR3, TLR7, MyD88, NF-κB p65 and tumor necrosis factor receptor-associated factor 3 in the lung tissues were significantly decreased by HHDC. These findings suggest that HHDC directly inhibited H1N1 infection in vivo and exerted a therapeutic effect on influenza-induced pneumonia in mice by modulating cytokines, antioxidant factors and TLR/MyD88/NF-κB signaling pathways.

Microwave-Assisted Enzymatic Extraction of Flavonoids from Armeniaca mume Sieb. Blossom and Their Immunomodulating Effect in Mice with DSS-Induced Colitis

Armeniaca mume Sieb. blossom is among the traditional Chinese edible flowers, and it is widely used in the food and pharmaceutical industries. Flavonoids are among the most abundant bioactive compounds in A. mume Sieb. blossom. However, the research on the extraction of flavonoids from A. mume Sieb. blossom and their immunomodulating function is insufficient. In this study, we developed a microwave-assisted enzymatic extraction of flavonoids from A. mume Sieb. blossom (FAMB) and explored their immunomodulating effect on mice with dextran sulfate sodium salt-induced colitis. The results showed that the optimum parameters for microwave-assisted enzymatic extraction of FAMB were as follows: cellulase: 2.0%; microwave power: 200 W; microwave action time: 5 min; and enzymatic hydrolysis time: 50 min. FAMB significantly promoted the lymphocyte proliferation and natural killer (NK) cell killing activity in colitis mice, and increased the concentrations of TNF-α, IFN-γ, and IL-2 in serum. FAMB also significantly reduced the apoptosis of spleen lymphocytes in these mice. These results demonstrated that the microwave-assisted enzymatic method could significantly improve the yield and efficacy extraction of FAMB. FAMB showed a good immunomodulation effect on colitis mice.

Herbal medicine, a reliable support in COVID therapy

At present, specific therapies for COVID-19 are not well established, being certain only that the immune system plays a decisive role in the initiation and progression of the disease. Plants have given and continue to give compounds with great efficiency and low toxicity, some of them being a starting point for extremely effective synthetic substances. Although herbal remedies are used mainly for preventive purposes, there are also guidelines issued by some countries that indicate the use of traditional remedies for different stages of COVID-19 disease.Europe has a long and strong tradition of using medicinal plants for therapeutic purposes, but clinical trials for this type of approach are scarce, compared to Asia. In this regard, a bridge between tradition and science, would have a strong impact on the capacity for prevention and treatment of COVID-19. The paper reviews compounds of plant origin that have previously proven effective in counteracting some coronaviruses but also some of their major effects - direct action on virus replicative apparatus (viral entry or replication, action on the viral enzymatic system), collateral action of natural compounds on the immune system and also the contribution of herbal medicine as vaccine adjuvants are tackled.

Punicalagin is a neuraminidase inhibitor of influenza viruses

Influenza A virus (IAV) causes great morbidity and mortality worldwide every year. However, there are only a limited number of drugs clinically available against IAV infection. Further, emergence of drug-resistant strains can render those drugs ineffective. Thus there is an unmet medical need to develop new anti-influenza agents. In this study, we show that punicalagin from plants possesses strong anti-influenza activity with a low micromolar IC₅₀ value in tissue culture. Using a battery of bioassays such as single-cycle replication assay, neuraminidase (NA) inhibition assay, and virus yield reduction assay, we demonstrate that the primary mechanism of action (MOA) of punicalagin is the NA-mediated viral release. Moreover, punicalagin can inhibit replication of different strains of influenza A and B viruses, including oseltamivir-resistant virus (NA/H274Y), indicating that punicalagin is a broad spectrum antiviral against both IAV and IBV. Further, although punicalagin targets NA like oseltamivir, it has a different MOA. These results suggest that punicalagin is an influenza NA inhibitor that may be further developed as a novel antiviral against influenza viruses.

Can network pharmacology identify the anti-virus and anti- inflammatory activities of Shuanghuanglian oral liquid used in Chinese medicine for respiratory tract infection?

Introduction

Shuanghuanglian (SHL) oral liquid is a well-known traditional Chinese medicine preparation administered for respiratory tract infections in China. However, the underlying pharmacological mechanisms remain unclear. The present study aims to determine the potential pharmacological mechanisms of SHL oral liquid based on network pharmacology.

Methods

A network pharmacology-based strategy including collection and analysis of putative compounds and target genes, network construction, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and Gene Ontology (GO) enrichment, identification of key compounds and target genes, and molecule docking was performed in this study.

Results

A total of 82 bioactive compounds and 226 putative target genes of SHL oral liquid were collected. Of note, 28 hub target genes including 4 major hub target genes: estrogen receptor 1 (ESR1), nuclear receptor coactivator 2 (NCOA2), nuclear receptor coactivator 1 (NCOA1), androgen receptor (AR) and 5 key compounds (quercetin, luteolin, baicalein, kaempferol and wogonin) were identified based on network analysis. The hub target genes mainly enriched in pathways including PI3K-Akt signaling pathway, human cytomegalovirus infection, and human papillomavirus infection, which could be the underlying pharmacological mechanisms of SHL oral liquid for treating diseases. Moreover, the key compounds had great molecule docking binding affinity with the major hub target genes.

Conclusion

Using network pharmacology analysis, SHL oral liquid was found to contain anti-virus, anti-inflammatory, and “multi-compounds and multi-targets” with therapeutic actions. These findings may provide a valuable direction for further clinical application and research.

Plants derived therapeutic strategies targeting chronic respiratory diseases: Chemical and immunological perspective

The apparent predicament of the representative chemotherapy for managing respiratory distress calls for an obligatory deliberation for identifying the pharmaceuticals that effectively counter the contemporary intricacies associated with target disease. Multiple, complex regulatory pathways manifest chronic pulmonary disorders, which require chemotherapeutics that produce composite inhibitory effect. The cost effective natural product based molecules hold a high fervor to meet the prospects posed by current respiratory-distress therapy by sparing the tedious drug design and development archetypes, present a robust standing for the possible replacement of the fading practice of poly-pharmacology, and ensure the subversion of a potential disease relapse. This study summarizes the experimental evidences on natural products moieties and their components that illustrates therapeutic efficacy on respiratory disorders.

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Plant derived therapeutics for managing chronic respiratory disorders.

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Activity of natural product based molecules on key regulatory pathways of COPD.

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Preclinical evidence for the efficacy of natural product moieties.

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Clinical significance of plant derived molecules in pulmonary distress.

Total flavonoids suppress lung cancer growth via the COX-2-mediated Wnt/β-catenin signaling pathway

The aim of the present study was to explore the anti-cancer effects of total flavonoids (TF) on lung cancer and to investigate the underlying mechanism. The inhibitory effect of TF on the proliferation of A549 cells in vitro was measured using an MTT assay. The apoptotic rate of TF-treated A549 cells was analyzed using flow cytometry and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling. Migration and invasion assays were performed to investigate the anti-migration effect of TF on A549 cells. Reverse-transcription quantitative PCR was used to analyze BCL2-like 2, BCL2, Bax, Bad, cyclooxygenase 2 (COX-2), Wnt and β-catenin mRNA expression levels in A549 cells. The in vivo anti-cancer effect of TF was investigated in a subcutaneous xenograft model of lung cancer in BALB/c nude mice. The results obtained in the present study revealed that TF exerted a significant inhibitory effect on the proliferation of A549 cells in a dose-dependent manner (P<0.01). TF induced apoptosis of A549 cells, which exhibited increased and decreased expression of pro- and anti- apoptotic genes, respectively. Furthermore, TF had a significant inhibitory effect on the migration and invasion of A549 cells (P<0.01). The mRNA expression levels of COX-2, Wnt and β-catenin were significantly downregulated in TF-treated A549 cells compared with controls. Additionally, treatment with TF inhibited tumor growth in mice, with a tumor inhibition rate of 64.07% compared with the controls. TF exhibited significant tumor inhibitory effects in vivo by promoting the apoptosis of tumor cells. In conclusion, the results suggested that TF may regulate lung cancer growth via the COX-2-Wnt/β-catenin signaling pathway. TF may serve as a novel anti-cancer agent for the treatment of lung cancer.

Flavonoids from Houttuynia cordata attenuate H1N1-induced acute lung injury in mice via inhibition of influenza virus and Toll-like receptor signalling

BACKGROUND

Influenza virus is one of the most important human pathogens, causing substantial seasonal and pandemic morbidity and mortality. Houttuynia cordata is a traditionally used medicinal plant for the treatment of pneumonia. Flavonoids are one of the major bioactive constituents of Houttuynia cordata.

PURPOSE

This study was designed to investigate the therapeutic effect and mechanism of flavonoid glycosides from H. cordata on influenza A virus (IAV)-induced acute lung injury (ALI) in mice.

METHODS

Flavonoids from H. cordata (HCF) were extracted from H. cordata and identified by high-performance liquid chromatography. Mice were infected intranasally with influenza virus H1N1 (A/FM/1/47). HCF (50, 100, or 200 mg/kg) or Ribavirin (100 mg/kg, the positive control) were administered intragastrically. Survival rates, life spans, weight losses, lung indexes, histological changes, inflammatory infiltration, and inflammatory markers in the lungs were measured. Lung virus titers and neuraminidase (NA) activities were detected. The expression of Toll-like receptors (TLRs) and levels of NF-κB p65 phosphorylation (NF-κB p65(p)) in the lungs were analysed. The effects of HCF on viral replication and TLR signalling were further evaluated in cells.

RESULTS

HCF contained 78.5% flavonoid glycosides. The contents of rutin, hyperin, isoquercitrin, and quercitrin in HCF were 8.8%, 26.7%, 9.9% and 31.7%. HCF (50, 100 and 200 mg/kg) increased the survival rate and life span of mice infected with the lethal H1N1 virus. In H1N1-induced ALI, mice treated with HCF (50, 100 and 200 mg/kg) showed lesser weight loss and lower lung index than the model group. The lungs of HCF-treated ALI mice presented more intact lung microstructural morphology, milder inflammatory infiltration, and lower levels of monocyte chemotactic protein 1 (MCP-1), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α) and malondialdehyde (MDA) than in the model group. Further investigation revealed that HCF exerted antiviral and TLR-inhibitory effects in vivo and in vitro. HCF (50, 100 and 200 mg/kg) reduced lung H1N1 virus titers and inhibited viral NA activity in mice. HCF (100 and 200 mg/kg) elevated the levels of interferon-β in lungs. HCF also decreased the expression of TLR3/4/7 and level of NF-κB p65(p) in lung tissues. In vitro experiments showed that HCF (50, 100 and 200 μg/ml) significantly inhibited viral proliferation and suppressed NA activity. In RAW 264.7 cells, TLR3, TLR4, and TLR7 agonist-stimulated cytokine secretion, NF-κB p65 phosphorylation, and nuclear translocation were constrained by HCF treatment. Furthermore, among the four major flavonoid glycosides in HCF, hyperin and quercitrin inhibited both viral replication and TLR signalling in cells.

CONCLUSION

HCF significantly alleviated H1N1-induced ALI in mice, which were associated with its dual antiviral and anti-inflammatory effects via inhibiting influenzal NA activity and TLR signalling. among the four major flavonoid glycosides in HCF, hyperin and quercitrin played key roles in the therapeutic effect of HCF.

The altered gut virome community in rhesus monkeys is correlated with the gut bacterial microbiome and associated metabolites

Background

The gut microbiome is closely associated with the health of the host; although the interaction between the bacterial microbiome and the whole virome has rarely been studied, it is likely of medical importance. Examination of the interactions between the gut bacterial microbiome and virome of rhesus monkey would significantly contribute to revealing the gut microbiome composition.

Methods

Here, we conducted a metagenomic analysis of the gut microbiome of rhesus monkeys in a longitudinal cohort treated with an antibiotic cocktail, and we documented the interactions between the bacterial microbiome and virome. The depletion of viral populations was confirmed at the species level by real-time PCR. We also detected changes in the gut metabolome by GC-MS and LC-MS.

Results

A majority of bacteria were depleted after treatment with antibiotics, and the Shannon diversity index decreased from 2.95 to 0.22. Furthermore, the abundance-based coverage estimator (ACE) decreased from 104.47 to 33.84, and the abundance of eukaryotic viruses also changed substantially. In the annotation, 6 families of DNA viruses and 1 bacteriophage family were present in the normal monkeys but absent after gut bacterial microbiome depletion. Intriguingly, we discovered that changes in the gut bacterial microbiome composition may promote changes in the gut virome composition, and tryptophan, arginine, and quinone may play roles in the interaction between the bacterial microbiome and virome.

Conclusion

Our results indicated that the clearly altered composition of the virome was correlated with depletion in the bacterial community and that metabolites produced by bacteria possibly play important roles in the interaction.

Electronic supplementary material

The online version of this article (10.1186/s12985-019-1211-z) contains supplementary material, which is available to authorized users.