Lianhuaqingwen capsule inhibits non-lethal doses of influenza virus-induced secondary Staphylococcus aureus infection in mice

Medicinal plants: bioactive compounds, biological activities, combating multidrug-resistant microorganisms, and human health benefits - a comprehensive review

In recent years, medicinal plants have gained significant attention in modern medicine due to their accessibility, affordability, widespread acceptance, and safety, making herbal remedies highly valued globally. Consequently, ensuring medicinal plants' quality, efficacy, and safety has become a critical concern for developed and developing nations. The emergence of multidrug-resistant microorganisms poses a serious global health threat, particularly in low-income regions, despite significant advancements in antimicrobial drugs and medical research over the past century. The rapid spread of these multidrug-resistant infections is primarily attributed to improper prescriptions, overuse, and unregulated access to antibiotics. Addressing these challenges, the standardization of plant-derived pharmaceuticals could pave the way for a transformative era in healthcare. Preserving and leveraging the historical knowledge of medicinal plants is essential before such valuable information is lost. Recently, there has been growing interest among natural and pharmaceutical scientists in exploring medicinal plants as potential sources of antimicrobial agents. This current review aims to identify the most common pathogens threatening human health, analyze the factors contributing to the rise of drug-resistant microorganisms, and evaluate the widespread use of medicinal plants across various countries as alternative antibiotics, highlighting their unique mechanisms of antimicrobial resistance.

Dual role of Baimao-Longdan-Congrong-Fang in inhibiting Staphylococcus aureus virulence factors and regulating TNF-α/TNFR1/NF-κB/MMP9 axis

BACKGROUND

Baimao-Longdan-Congrong-Fang (BLCF), a traditional Chinese herbal formula described in the Taiping Shenghui Fang (998 AD), consists of medicinal plants with heat-clearing and tonifying properties. BLCF has a promise as a treatment for Staphylococcus aureus (S. aureus) pneumonia, according to its historical use and current pharmacological research.

PURPOSE

In this study, the inhibitory effects of BLCF on S. aureus virulence factors were evaluated in vitro, and its mechanisms of action were investigated in a methicillin-resistant S. aureus (MRSA) pneumonia mouse model.

METHODS

The inhibitory effect of BLCF on S. aureus virulence factors, including sortase A (SrtA) and α-hemolysin (Hla), was investigated by fluorescence resonance energy transfer (FRET) and hemolysis assays. A C57BL/6J mouse model of MRSA pneumonia was employed to evaluate its therapeutic efficacy. Accordingly, an integrated strategy of medicinal chemistry, network pharmacology analysis, GEO database analysis, bioinformatics, molecular docking, molecular dynamics simulation, GeneMANIA-based functional association (GMFA), and GSEA was used to identify and illustrate potential therapeutic targets and mechanisms. Subsequently, the mechanistic results were confirmed by Western blot analysis and RT-qPCR.

RESULTS

While BLCF exhibited weak inhibitory activity against S. aureus USA300, Newman, and SA37 strains, it significantly suppressed SrtA-related virulence functions without affecting bacterial growth. FRET and hemolysis assays confirmed that BLCF inhibited SrtA activity (IC50 = 1.25 mg/mL) while decreasing hemolytic activity. Furthermore, BLCF protected mice from MRSA infection, increasing their survival rates. Bioinformatics analysis identified 26 active compounds and 2 hub genes (Tnf and Mmp9) that were associated with 5 types of immune cell, including activated CD4 T cells, myeloid-derived suppressor cells, activated dendritic cells, macrophages, and mast cells. Molecular docking revealed 3 active compounds (isoacteoside, verbascoside, and echinacoside) that exhibited strong binding affinities to TNF, MMP9, and SrtA. Molecular dynamics simulations validated the stable interactions between isoacteoside and the target proteins, yielding binding energies of -136.76 ± 8.83 kJ/mol, -174.98 ± 14.89 kJ/mol, and -186.34 ± 9.06 kJ/mol, respectively. The therapeutic effect of BLCF was closely linked to the NF-κB signaling pathway, as revealed by GMFA and GSEA analyses. In vivo, BLCF reduced lung bacterial load, improved the wet/dry ratio, and decreased inflammatory cytokines, thereby enhancing lung histopathology through modulation of the TNF-α/TNFR1/NF-κB/MMP9 axis.

CONCLUSIONS

BLCF can effectively treat MRSA pneumonia in mice by inhibiting SrtA activity, decreasing hemolytic activity, and regulating the TNF-α/TNFR1/NF-κB/MMP9 axis. These findings suggest BLCF, a traditional herbal formula, as a promising novel therapeutic approach to treat pneumonia.

Jing-Yin-Gu-Biao formula protects mice from postinfluenza Staphylococcus aureus infection by ameliorating acute lung injury and improving hypercoagulable state via inhibiting NETosis

Background

Jing-Yin-Gu-Biao formula (JYGBF) is a Chinese medicine derived from Yupingfeng power, Huoxiangzhengqi powder and Yinqiao powder, and has been widely used to treat acute respiratory infections. This study aims to observe the effects of JYGBF against postinfluenza Staphylococcus aureus (S. aureus) infection.

Purpose and study design

A mouse model of secondary S. aureus infection following PR8 infection was established to evaluate the protective effects of JYGBF against postinfluenza Staphylococcus aureus (S. aureus) infection and related mechanisms were validated in vivo and in vitro.

Results

The administration of JYGBF significantly ameliorated acute lung injury (ALI) and inhibited overactivated inflammatory response (MIP-2, IL-6, etc.) in mice with postinfluenza S. aureus infection. Single cell RNA-sequencing (scRNA-seq) data indicated that neutrophils had the highest cytokine score in lungs and JYGBF inhibited neutrophil chemotaxis, reactive oxygen species (ROS) biosynthesis and ERK1/2 cascades in neutrophils. Meanwhile, JYGBF inhibited the formation of neutrophil extracellular traps (NETs) in lungs, which is characterized by the production of ROS, peptidyl arginine deiminase 4 (PAD4), citrullinated histone H3 (CitH3), myeloperoxidase (MPO), neutrophil elastase (NE), S100A8/A9 and MPO-CitH3 colocalization. Moreover, JYGBF decreased platelet counts and the expression of its activated markers (CD62P and αIIbβ3) accompanied by the drop of fibrinogen (FIB) and fibrin degradation product (FDP), accounting for alleviating hypercoagulable state. JYGBF inhibited ERK1/2 phosphorylation in neutrophils and in lungs of infected mice. Acacetin, a critical compound from JYGBF, inhibited NET formation via downregulating ERK/ROS axis.

Conclusions

These results indicated that JYGBF inhibited NET formation and overactivated inflammatory response by suppressing ERK/ROS axis in neutrophils, thereby mitigating ALI and improving the hypercoagulable state during postinfluenza S. aureus infection. JYGBF could be considered a potent therapeutic agent for the prevention and treatment of postinfluenza bacterial infection.

Synergistic effects of Lianhuaqingwen in combination with Oseltamivir and Baloxavir against seasonal influenza virus: In vitro and in vivo assessment

ETHNOPHARMACOLOGICAL RELEVANCE

Lianhuaqingwen (LH), a traditional Chinese medicine, presents a broad-spectrum antiviral effect and has been widely used to treat influenza. Given the potential rise of drug-resistant influenza viruses, it is necessary to develop new antiviral drugs and explore combination therapies involving LH in tandem with existing antivirals such as Oseltamivir acid (Osel) or Baloxavir (Bal). These multidrug combinations could help effectively control the seasonal influenza epidemics and reduce the disease burden.

AIM OF THE STUDY

This study aimed to evaluate the antiviral effects of LH, alone and in combination with Osel or Bal, against human seasonal influenza viruses in vitro and in vivo models.

MATERIALS AND METHODS

The antiviral efficacy of LH alone and LH in combination with Osel/Bal against seasonal influenza A viruses (IAVs) (H1N1 and H3N2 subtypes) and influenza B viruses (IBVs) (BV- and BY-lineages) was assessed in vitro using MDCK cells. The median effective concentration (EC50) was determined, and the drug synergies were analyzed. Additionally, the antiviral activity of LH monotherapy and LH + Osel/Bal combination therapy were evaluated in vivo using an H1N1-infected BABL/c mouse model by monitoring changes in body weight, survival rate, lung viral titer, pathological damage, and inflammatory reaction.

RESULTS

In vitro, LH alone and in combination with Osel/Bal exhibited antiviral activity against both IAVs and IBVs. The addition of LH to Osel/Bal improved the therapeutic efficacy compared to Osel/Bal alone. In vivo, LH monotherapy reduced body weight loss and increased the survival rates of H1N1-infected mice. LH in combination with Osel/Bal resulted in lower virus titers, more effective relief of pathological damage, and comparable low expression of inflammatory factors in the lungs of H1N1-infected mice compared to the use of Osel/Bal alone. Transcriptomic analysis of the lungs revealed that LH + Osel/Bal significantly increased the expression of genes associated with antiviral and anti-inflammatory effects.

CONCLUSIONS

This study evaluated the antiviral effects of LH monotherapy and combination therapy with Osel/Bal against human seasonal influenza viruses in vitro and in vivo models. The results suggest that combining LH with Osel or Bal could enhance the antiviral efficiency for influenza viruses compared to the monotherapy using any of these three drugs.

Inhibitory Effect of Jingfang Mixture on Staphylococcus aureus α-Hemolysin

Staphylococcus aureus (S. aureus) is a kind of gram-positive bacteria, and its virulence factors can cause many kinds of infections. Traditional antibiotics can not only kill bacteria, but also easily lead to bacterial resistance. Jingfang Mixture (JFM) is commonly used in clinic to prevent and treat epidemic diseases and infectious diseases. The main purpose of this study is to explore the inhibitory effect of JFM on alpha-hemolysin (Hla) of S. aureus and to alleviate the damage caused by Hla. We found that JFM could inhibit the hemolytic activity, gene and protein level and neutralizing activity of Hla in a dose-dependent manner at the concentrations of 125, 250 and 500 μg/mL, without affecting the growth of bacteria. In addition, JFM reduced the damage of Hla to A549 cells and the release of lactate dehydrogenase (LDH). We also observed that in the S. aureus - induced pneumonia mouse model, JFM could significantly prolong the life of mice, reduce the bacterial load in the lungs, significantly improve the pathological state of the lungs and alleviate the damage caused by inflammatory factors, and the pathogenicity of gene deletion strain DU 1090 of S. aureus to pneumonia mice was also significantly reduced. In conclusion, this study proved that JFM is a potential drug against S. aureus infection, and this study provided a preliminary study for better guidance of clinical drug use.

Inhibitory effect of Jingfang mixture on Staphylococcus aureus α-hemolysin

Staphylococcus aureus is a gram-positive bacteria, and its virulence factors can cause many kinds of infections, such as pneumonia, sepsis, enteritis and osteomyelitis. Traditional antibiotics can not only kill bacteria, but also easily lead to bacterial resistance. Jingfang Mixture (JFM) has the effects of inducing sweating and relieving the exterior, dispelling wind and eliminating dampness, and is commonly used in clinic to prevent and treat epidemic diseases and infectious diseases. The main purpose of this study is to explore the inhibitory effect of JFM on alpha-hemolysin (Hla) of S. aureus and to alleviate the damage caused by Hla. We found that JFM could inhibit the hemolytic activity, transcription level and neutralizing activity of Hla in a dose-dependent manner at the concentrations of 125, 250 and 500 µg/mL, without affecting the growth of bacteria. In addition, JFM reduced the damage of Hla to A549 cells and the release of lactate dehydrogenase (LDH). We also observed that in the S. aureus - induced pneumonia mouse model, JFM could significantly prolong the life of mice, reduce the bacterial load in the lungs, significantly improve the pathological state of the lungs and alleviate the damage caused by inflammatory factors, and the pathogenicity of gene deletion strain DU 1090 of S. aureus to pneumonia mice was also significantly reduced. In conclusion, this study proved that JFM is a potential drug against S. aureus infection, and this study provided a preliminary study for better guidance of clinical drug use.

Staphylococcus aureus wraps around Candida albicans and synergistically escapes from Neutrophil extracellular traps

Background

NETs, a unique neutrophil immune mechanism, are vital in defending against microbial invasions. Understanding the mechanisms of co-infection by Candida albicans and Staphylococcus aureus, which often leads to higher mortality and poorer prognosis, is crucial for studying infection progression.

Methods

In our study, we established a mouse model of subcutaneous infection to characterize the inflammation induced by co-infection. By purifying and extracting NETs to interact with microorganisms, we delve into the differences in their interactions with various microbial species. Additionally, we investigated the differences in NETs production by neutrophils in response to single or mixed microorganisms through the interaction between neutrophils and these microorganisms. Furthermore, we analyzed the gene expression differences during co-infection using transcriptomics.

Results

In vivo, C. albicans infections tend to aggregate, while S. aureus infections are more diffuse. In cases of co-infection, S. aureus adheres to and wraps C. albicans. NETs exhibit strong killing capability against C. albicans but weaker efficacy against S. aureus. When NETs interact with mixed microorganisms, they preferentially target and kill the outer layer of S. aureus. In the early stages, neutrophils primarily rely on phagocytosis to kill S. aureus, but as the bacteria accumulate, they stimulate neutrophils to produce NETs. Interestingly, in the presence of neutrophils, S. aureus promotes the proliferation and hyphal growth of C. albicans.

Conclusion

Our research has showed substantial differences in the progression of co-infections compared to single-microbial infections, thereby providing scientific evidence for NETs as potential therapeutic targets in the treatment of co-infections.

The phytochemistry, pharmacology, pharmacokinetics, quality control, and toxicity of Forsythiae Fructus: An updated systematic review

Forsythiae Fructus (FF), the dried fruit of F. suspensa, is commonly used to treat fever, inflammation, etc in China or other Asian countries. FF is usually used as the core herb in traditional Chinese medicine preparations for the treatment of influenza, such as Shuang-huang-lian oral liquid and Yin-qiao powder, etc. Since the wide application and core role of FF, its research progress was summarized in terms of traditional uses, phytochemistry, pharmacology, pharmacokinetics, quality control, and toxicity. Meanwhile, the anti-influenza substances and mechanism of FF were emphasized. Till now, a total of 290 chemical components are identified in F. suspensa, and among them, 248 components were isolated and identified from FF, including 42 phenylethanoid glycosides, 48 lignans, 59 terpenoids, 14 flavonoids, 3 steroids, 24 cyclohexyl ethanol derivatives, 14 alkaloids, 26 organic acids, and 18 other types. FF and their pure compounds have the pharmacological activities of anti-virus, anti-inflammation, anti-oxidant, anti-bacteria, anti-tumor, neuroprotection, hepatoprotection, etc. Inhibition of TLR7, RIG-I, MAVS, NF-κB, MyD88 signaling pathway were the reported anti-influenza mechanisms of FF and phenylethanoid glycosides and lignans are the main active groups. However, the bioavailability of phenylethanoid glycosides and lignans of FF in vivo was low, which needed to be improved. Simultaneously, the un-elucidated compounds and anti-influenza substances of FF strongly needed to be explored. The current quality control of FF was only about forsythoside A and phillyrin, more active components should be taken into consideration. Moreover, there are no reports of toxicity of FF yet, but the toxicity of FF should be not neglected in clinical applications.

Lianhua Qingwen protects LPS-induced acute lung injury by promoting M2 macrophage infiltration

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine Lianhua Qingwen (LHQW) was used to treat regular seasonal influenza. In recent years, LHQW exerts significant therapeutic effects in treating influenza and Coronavirus Disease 2019 (COVID-19). However, the potential mechanisms are not yet understood and need further study.

AIM OF STUDY

This study aims to look into the influence of LHQW on lung inflammation and macrophage phenotype, and to clarify the connection between macrophage plasticity and LHQW.

METHODS

The cell viability, marker expression, response to LPS stimulation, and phagocytosis of Raw264.7 were detected after LHQW treatment. In an LPS-induced acute lung injury (ALI) mouse model, the alleviating effect of LHQW on lung injury was investigated. The total macrophages and M2 macrophages in mice lungs and the peripheral blood monocytes after LHQW treatment were detected. The cell viability and polarization of peripheral blood macrophages treated with LHQW were detected.

RESULTS

Here, we demonstrate that LHQW protects LPS-induced ALI by promoting M2 macrophage infiltration. LHQW treatment inhibited the inflammatory response and pro-inflammatory phenotype of Raw264.7 macrophages. High concentrations of LHQW promoted the phagocytic capacity of Raw264.7 macrophages. In an ALI mouse model, LHQW alleviated lung injury and no significant hepatotoxicity was observed. By Immunohistochemistry (IHC) analysis, LHQW increased the infiltration of macrophages, mainly M2 macrophages. Consistent with Raw264.7, LHQW also decreased the expression of M1 markers in peripheral blood macrophages. In addition, LHQW blood plasma promoted the M2-type polarization of peripheral blood macrophages.

CONCLUSIONS

Taken together, our data demonstrate that LHQW reduces the inflammatory response and ameliorates acute lung injury by promoting anti-inflammatory polarization of macrophages.

Efficacy and safety of Lianhua Qingwen as an adjuvant treatment for influenza in Chinese patients: A meta-analysis

BACKGROUND

Lianhua Qingwen (LHQW) is a proprietary traditional Chinese medicine for the treatment of influenza (FLu). It is composed of 2 prescriptions, Maxing Shigan and Yinqiao, which has antiviral, antibacterial, and immunomodulatory effects. However its clinical suitability has not yet been investigated.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of LHQW in the treatment of FLu.

METHODS

We searched several databases, including PubMed and China Biomedical Database for literature research, from inception to July 1, 2023. This meta-analysis included RCTs that compared the safety and efficacy of the combination of LHQW and conventional drugs (CD) with CD alone for IFU. The extracted data were analyzed using Revman5.4 software with risk ratio (RR), 95% confidence intervals (CI), and standardized mean difference.

RESULTS

Our meta-analysis included 32 articles with 3592 patients. The results showed that the effects of LHQW adjuvant therapy were superior to those of CD (clinical effective rate: RR = 1.22, 95% CI: 1.18-1.26, P < .00001; cure rate: RR = 1.54, 95% CI: 1.35-1.75, P < .00001), and adverse reactions after treatment were significantly lower than those before treatment (RR = 0.70, 95% CI: 0.50-0.98, P = .04).

CONCLUSION

This meta-analysis indicates that LHQW combined with CD may be more effective than CD alone for the treatment of FLu.

Lonicera japonica Thunb. as a promising antibacterial agent for Bacillus cereus ATCC14579 based on network pharmacology, metabolomics, and in vitro experiments

Lonicera japonica Thunb. has attracted much attention for its treatment of bacterial and viral infectious diseases, while its active ingredients and potential mechanisms of action have not been fully elucidated. Here, we combined metabolomics, and network pharmacology to explore the molecular mechanism of Bacillus cereus ATCC14579 inhibition by Lonicera japonica Thunb. In vitro inhibition experiments showed that the Lonicera japonica Thunb.'s water extracts, ethanolic extract, luteolin, quercetin, and kaempferol strongly inhibited Bacillus cereus ATCC14579. In contrast, chlorogenic acid and macranthoidin B had no inhibitory effect on Bacillus cereus ATCC14579. Meanwhile, the minimum inhibitory concentrations of luteolin, quercetin, and kaempferol against Bacillus cereus ATCC14579 were 15.625 μg mL-1, 31.25 μg mL-1, and 15.625 μg mL-1. Based on the previous experimental basis, the metabolomic analysis showed the presence of 16 active ingredients in Lonicera japonica Thunb.'s water extracts and ethanol extracts, with differences in the luteolin, quercetin, and kaempferol contents between the water extracts and ethanol extracts. Network pharmacology studies indicated that fabZ, tig, glmU, secA, deoD, nagB, pgi, rpmB, recA, and upp were potential key targets. Active ingredients of Lonicera japonica Thunb. may exert their inhibitory effects by inhibiting ribosome assembly, the peptidoglycan biosynthesis process, and the phospholipid biosynthesis process of Bacillus cereus ATCC14579. An alkaline phosphatase activity assay, peptidoglycan concentration assay, and protein concentration assay showed that luteolin, quercetin, and kaempferol disrupted the Bacillus cereus ATCC14579 cell wall and cell membrane integrity. Transmission electron microscopy results showed significant changes in the morphology and ultrastructure of the cell wall and cell membrane of Bacillus cereus ATCC14579, further confirming the disruption of the cell wall and cell membrane integrity of Bacillus cereus ATCC14579 by luteolin, quercetin, and kaempferol. In conclusion, Lonicera japonica Thunb. can be used as a potential antibacterial agent for Bacillus cereus ATCC14579, which may exert its antibacterial activity by destroying the integrity of the cell wall and membrane.