Potential Treatment of COVID-19 with Traditional Chinese Medicine: What Herbs Can Help Win the Battle with SARS-CoV-2?

A Novel pH-Responsive Baicalein@Chitosan Hydrogel for the Topical Treatment of Herpes Simplex Virus Type 1 Skin Infections: Therapeutic Potential and Mechanisms

Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen primarily transmitted through skin-to-skin contact. Traditional antiviral drugs like acyclovir (ACV) have limitations due to viral resistance and side effects, necessitating the development of alternative therapeutic strategies. Drug-loaded hydrogels have emerged as a promising approach for managing various skin infections. Considering the low-pH microenvironment following HSV-1 infection, a pH-responsive baicalein@chitosan (B@C) hydrogel is developed for the topical treatment of HSV-1 skin infections. This hydrogel is synthesized by incorporating baicalein, a natural flavonoid, into a chitosan matrix modified with 4-formylphenylboronic acid and protocatechualdehyde to achieve potent anti-HSV-1 activity and pH-responsiveness. In vitro results demonstrated the hydrogel's pH-dependent inhibitory effect on HSV-1 infections, including ACV-resistant strains. Subsequent investigations confirmed its efficacy in multiple murine infection models. Mechanistically, the B@C hydrogel inhibited viral replication by modulating the phosphorylation of inhibitor of nuclear factor kappa-B kinase subunit beta, promoted collagen synthesis, and decreased reactive oxygen species generation. Ultra-high-performance liquid chromatography-tandem mass spectrometry analysis revealed a sustained release of baicalein from the hydrogel, ensuring long-term drug retention in HSV-1-infected skin tissues. Collectively, these findings suggest that the B@C hydrogel holds significant potential for the therapeutic management of HSV-1 skin infections.

Chinese Medicine for Treatment of COVID-19: A Review of Potential Pharmacological Components and Mechanisms

Coronavirus disease 2019 (COVID-19) is an acute infectious respiratory disease that has been prevalent since December 2019. Chinese medicine (CM) has demonstrated its unique advantages in the fight against COVID-19 in the areas of disease prevention, improvement of clinical symptoms, and control of disease progression. This review summarized the relevant material components of CM in the treatment of COVID-19 by searching the relevant literature and reports on CM in the treatment of COVID-19 and combining with the physiological and pathological characteristics of the novel coronavirus. On the basis of sorting out experimental methods in vivo and in vitro, the mechanism of herb action was further clarified in terms of inhibiting virus invasion and replication and improving related complications. The aim of the article is to explore the strengths and characteristics of CM in the treatment of COVID-19, and to provide a basis for the research and scientific, standardized treatment of COVID-19 with CM.

Exploring the Effect and Mechanism of DaYuan Yin Against Acute Lung Injury by Network Pharmacology, Molecular Docking, and Experimental Validation

Background

DaYuan Yin (DYY), a traditional Chinese medicine for lung diseases, requires further study to understand how it improves acute lung injury (ALI). This study seeks to elucidate the material basis and molecular mechanisms underlying the treatment of ALI with DYY through network pharmacology, molecular docking, and experimental validation.

Methods

DYY's active components and targets were identified using TCMSP and UHPLC-MS/MS, and a herb-component-target network was created with Cytoscape 3.7.2. ALI target genes were sourced from GeneCards, DisGeNET, and DrugBank. A PPI network was built, with core targets analyzed through GO and KEGG enrichment via Metscape. The therapeutic effects and mechanisms of DYY on LPS-induced ALI in rats were explored, and molecular docking evaluated the interactions between Nrf2, HO-1, TLR4, and the components.

Results

The study identified 95 active compounds, 234 therapeutic targets, and 2529 ALI-related genes, with 111 shared targets between DYY and ALI. KEGG analysis indicates that the PI3K-AKT, MAPK, and oxidative stress pathways are associated with DYY's anti-ALI effects. Network pharmacology and UHPLC-MS/MS analysis revealed active ingredients like quercetin, Magnolol, and Wogonin. Compared with the model group, DYY reduced the lung dry-wet ratio (W/D) of ALI rats from (5.31 ± 0.51) to (4.47 ± 0.73)(P < 0.05). Meanwhile, the contents of IL-6 and TNF-α in bronchoalveolar lavage fluid (BALF) and MDA, NO and ROS in lung tissue were also significantly decreased. Notably, DYY enhances UCP2 mRNA expression, boosts Nrf2 and HO-1 expression, and inhibits TLR4-mediated pro-inflammatory mediators. Molecular docking analysis showed that the main components of DYY had strong binding ability with HO-1.

Conclusion

DYY can alleviate inflammation, oxidative stress, and ALI-related changes by targeting the Nrf2/HO-1 mediated TLR4 pathway, providing insights for developing effective ALI treatments.

The high-quality genome of Grona styracifolia uncovers the genomic mechanism of high levels of schaftoside, a promising drug candidate for treatment of COVID-19

Recent study has evidenced that traditional Chinese medicinal (TCM) plant-derived schaftoside shows promise as a potential drug candidate for COVID-19 treatment. However, the biosynthetic pathway of schaftoside in TCM plants remains unknown. In this study, the genome of the TCM herb Grona styracifolia (Osbeck) H.Ohashi & K.Ohashi (GSO), which is rich in schaftoside, was sequenced, and a high-quality assembly of GSO genome was obtained. Our findings revealed that GSO did not undergo recent whole genome duplication (WGD) but shared an ancestral papilionoid polyploidy event, leading to the gene expansion of chalcone synthase (CHS) and isoflavone 2'-hydroxylase (HIDH). Furthermore, GSO-specific tandem gene duplication resulted in the gene expansion of C-glucosyltransferase (CGT). Integrative analysis of the metabolome and transcriptome identified 13 CGTs and eight HIDHs involved in the biosynthetic pathway of schaftoside. Functional studies indicated that CGTs and HIDHs identified here are bona fide responsible for the biosynthesis of schaftoside in GSO, as confirmed through hairy root transgenic system and in vitro enzyme activity assay. Taken together, the ancestral papilionoid polyploidy event expanding CHSs and HIDHs, along with the GSO-specific tandem duplication of CGT, contributes, partially if not completely, to the robust biosynthesis of schaftoside in GSO. These findings provide insights into the genomic mechanisms underlying the abundant biosynthesis of schaftoside in GSO, highlighting the potential of GSO as a source of bioactive compounds for pharmaceutical development.

Development and management of gastrointestinal symptoms in long-term COVID-19

Background

Emerging evidence reveals that SARS-CoV-2 possesses the capability to disrupt the gastrointestinal (GI) homeostasis, resulting in the long-term symptoms such as loss of appetite, diarrhea, gastroesophageal reflux, and nausea. In the current review, we summarized recent reports regarding the long-term effects of COVID-19 (long COVID) on the gastrointestine.

Objective

To provide a narrative review of abundant clinical evidence regarding the development and management of long-term GI symptoms in COVID-19 patients.

Results

Long-term persistent digestive symptoms are exhibited in a majority of long-COVID patients. SARS-CoV-2 infection of intestinal epithelial cells, cytokine storm, gut dysbiosis, therapeutic drugs, psychological factors and exacerbation of primary underlying diseases lead to long-term GI symptoms in COVID-19 patients. Interventions like probiotics, prebiotics, fecal microbiota transplantation, and antibiotics are proved to be beneficial in preserving intestinal microecological homeostasis and alleviating GI symptoms.

Conclusion

Timely diagnosis and treatment of GI symptoms in long-COVID patients hold great significance as they may contribute to the mitigation of severe conditions and ultimately lead to the improvement of outcomes of the patients.

Xuanfei Baidu decoction in the treatment of coronavirus disease 2019 (COVID-19): Efficacy and potential mechanisms

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide and become a major global public health concern. Although novel investigational COVID-19 antiviral candidates such as the Pfizer agent PAXLOVID™, molnupiravir, baricitinib, remdesivir, and favipiravir are currently used to treat patients with COVID-19, there is still a critical need for the development of additional treatments, as the recommended therapeutic options are frequently ineffective against SARS-CoV-2. The efficacy and safety of vaccines remain uncertain, particularly with the emergence of several variants. All 10 versions of the National Health Commission's diagnosis and treatment guidelines for COVID-19 recommend using traditional Chinese medicine. Xuanfei Baidu Decoction (XFBD) is one of the "three Chinese medicines and three Chinese prescriptions" recommended for COVID-19. This review summarizes the clinical evidence and potential mechanisms of action of XFBD for COVID-19 treatment. With XFBD, patients with COVID-19 experience improved clinical symptoms, shorter hospital stay, prevention of the progression of their symptoms from mild to moderate and severe symptoms, and reduced mortality in critically ill patients. The mechanisms of action may be associated with its direct antiviral, anti-inflammatory, immunomodulatory, antioxidative, and antimicrobial properties. High-quality clinical and experimental studies are needed to further explore the clinical efficacy and underlying mechanisms of XFBD in COVID-19 treatment.

Unraveling the mechanism of action of cepharanthine for the treatment of novel coronavirus pneumonia (COVID-19) from the perspectives of systematic pharmacology

Natural products play an irreplaceable role in the treatment of SARS-CoV-2 infection. Nevertheless, the underlying molecular mechanisms involved remain elusive. To better understand their potential therapeutic effects, more validation studies are needed to explore underlying mechanisms systematically. This study aims to explore the potential targets of action and signaling pathways of cepharanthine for the treatment of COVID-19. This study revealed that a total of 173 potential targets of action for Cepharanthine and 86 intersectional targets for Cepharanthine against COVID-19 were screened and collected. Gene Ontology enrichment analysis suggested that inflammatory, immune cell and enzyme activities were the critical terms for cepharanthine against COVID-19. Pathway enrichment analysis showed that five pathways associated with COVID-19 were the main signaling pathways for the treatment of COVID-19 via cepharanthine. Molecular docking and molecular dynamics simulations suggested that 6 core targets were regarded as potential targets for cepharanthine against COVID-19. In brief, the study demonstrates that cepharanthine may play an important role in the treatment of SARS-CoV-2 infection through its harmonious activity against SARS-CoV-2 pathways and multiple related targets. This article provides valuable insights required to respond effectively to concerns of western medical community.

Qi-Dong-Huo-Xue-Yin balances the immune microenvironment to protect against LPS induced acute lung injury

COVID-19 induces acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and leads to severe immunological changes that threatens the lives of COVID-19 victims. Studies have shown that both the regulatory T cells and macrophages were deranged in COVID-19-induced ALI. Herbal drugs have long been utilized to adjust the immune microenvironment in ALI. However, the underlying mechanisms of herbal drug mediated ALI protection are largely unknown. This study aims to understand the cellular mechanism of a traditional Chinese medicine, Qi-Dong-Huo-Xue-Yin (QD), in protecting against LPS induced acute lung injury in mouse models. Our data showed that QD intrinsically promotes Foxp3 transcription via promoting acetylation of the Foxp3 promoter in CD4⁺ T cells and consequently facilitates CD4⁺CD25⁺Foxp3⁺ Tregs development. Extrinsically, QD stabilized β-catenin in macrophages to expedite CD4⁺CD25⁺Foxp3⁺ Tregs development and modulated peripheral blood cytokines. Taken together, our results illustrate that QD promotes CD4⁺CD25⁺Foxp3⁺ Tregs development via intrinsic and extrinsic pathways and balanced cytokines within the lungs to protect against LPS induced ALI. This study suggests a potential application of QD in ALI related diseases.

Bioactive compounds from Huashi Baidu decoction possess both antiviral and anti-inflammatory effects against COVID-19

The coronavirus disease 2019 (COVID-19) pandemic is an ongoing global health concern, and effective antiviral reagents are urgently needed. Traditional Chinese medicine theory-driven natural drug research and development (TCMT-NDRD) is a feasible method to address this issue as the traditional Chinese medicine formulae have been shown effective in the treatment of COVID-19. Huashi Baidu decoction (Q-14) is a clinically approved formula for COVID-19 therapy with antiviral and anti-inflammatory effects. Here, an integrative pharmacological strategy was applied to identify the antiviral and anti-inflammatory bioactive compounds from Q-14. Overall, a total of 343 chemical compounds were initially characterized, and 60 prototype compounds in Q-14 were subsequently traced in plasma using ultrahigh-performance liquid chromatography with quadrupole time-of-flight mass spectrometry. Among the 60 compounds, six compounds (magnolol, glycyrrhisoflavone, licoisoflavone A, emodin, echinatin, and quercetin) were identified showing a dose-dependent inhibition effect on the SARS-CoV-2 infection, including two inhibitors (echinatin and quercetin) of the main protease (Mpro), as well as two inhibitors (glycyrrhisoflavone and licoisoflavone A) of the RNA-dependent RNA polymerase (RdRp). Meanwhile, three anti-inflammatory components, including licochalcone B, echinatin, and glycyrrhisoflavone, were identified in a SARS-CoV-2-infected inflammatory cell model. In addition, glycyrrhisoflavone and licoisoflavone A also displayed strong inhibitory activities against cAMP-specific 3',5'-cyclic phosphodiesterase 4 (PDE4). Crystal structures of PDE4 in complex with glycyrrhisoflavone or licoisoflavone A were determined at resolutions of 1.54 Å and 1.65 Å, respectively, and both compounds bind in the active site of PDE4 with similar interactions. These findings will greatly stimulate the study of TCMT-NDRD against COVID-19.

In silico screening of phenylethanoid glycosides, a class of pharmacologically active compounds as natural inhibitors of SARS-CoV-2 proteases

Since the advent of Covid-19, several natural products have been investigated regarding their in silico interactions with SARS-CoV-2 proteases - 3CL^pro and PL^pro, two of the most important pharmacological targets for antiviral development. Phenylethanoid glycosides (PG) are a class of natural products present in important medicinal plants and a drug containing this group of active ingredients has been successfully used in the treatment of Covid-19 in China. Thus, a dataset with 567 derivatives of this class was built from reviews published between 1994 and 2020, and their interaction against both SARS-CoV-2 proteases was investigated. The virtual screening was performed by filtering the PGs through the evaluation of scores based on the AutoDock Vina, GOLD/ChemPLP, and GOLD/GoldScore evaluation functions. The bRO5 pharmacokinetic parameters of the PGs ranked in the previous step were analyzed and their interaction with key amino acid residues of the 3CL^pro and PL^pro enzymes was evaluated. Ninety-eight compounds were identified by computational approaches against PL^pro and 80 PGs against 3CL^pro. Of these, four interacted with key catalytic residues of PL^pro, which is an indicative of inhibitory activity, and three compounds interacted with catalytic key residues of 3CL^pro. Of these, five PGs occur in plants of the Traditional Chinese Medicine (TCM), while two are components of plants/formulations currently used in the Covid-19 protocols in China. The data presented here show the potential of PGs as selective inhibitors of SARS-CoV-2 3CL^pro and PL^pro.

The Global Impact of COVID-19: Historical Development, Molecular Characterization, Drug Discovery and Future Directions

In December 2019, an outbreak of a respiratory disease called the coronavirus disease 2019 (COVID-19) caused by a new coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began in Wuhan, China. The SARS-CoV-2, an encapsulated positive-stranded RNA virus, spread worldwide with disastrous consequences for people's health, economies, and quality of life. The disease has had far-reaching impacts on society, including economic disruption, school closures, and increased stress and anxiety. It has also highlighted disparities in healthcare access and outcomes, with marginalized communities disproportionately affected by the SARS-CoV-2. The symptoms of COVID-19 range from mild to severe. There is presently no effective cure. Nevertheless, significant progress has been made in developing COVID-19 vaccine for different therapeutic targets. For instance, scientists developed multifold vaccine candidates shortly after the COVID-19 outbreak after Pfizer and AstraZeneca discovered the initial COVID-19 vaccines. These vaccines reduce disease spread, severity, and mortality. The addition of rapid diagnostics to microscopy for COVID-19 diagnosis has proven crucial. Our review provides a thorough overview of the historical development of COVID-19 and molecular and biochemical characterization of the SARS-CoV-2. We highlight the potential contributions from insect and plant sources as anti-SARS-CoV-2 and present directions for future research.

In Silico Identification of Anti-SARS-CoV-2 Medicinal Plants Using Cheminformatics and Machine Learning

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of COVID-19, is spreading rapidly and has caused hundreds of millions of infections and millions of deaths worldwide. Due to the lack of specific vaccines and effective treatments for COVID-19, there is an urgent need to identify effective drugs. Traditional Chinese medicine (TCM) is a valuable resource for identifying novel anti-SARS-CoV-2 drugs based on the important contribution of TCM and its potential benefits in COVID-19 treatment. Herein, we aimed to discover novel anti-SARS-CoV-2 compounds and medicinal plants from TCM by establishing a prediction method of anti-SARS-CoV-2 activity using machine learning methods. We first constructed a benchmark dataset from anti-SARS-CoV-2 bioactivity data collected from the ChEMBL database. Then, we established random forest (RF) and support vector machine (SVM) models that both achieved satisfactory predictive performance with AUC values of 0.90. By using this method, a total of 1011 active anti-SARS-CoV-2 compounds were predicted from the TCMSP database. Among these compounds, six compounds with highly potent activity were confirmed in the anti-SARS-CoV-2 experiments. The molecular fingerprint similarity analysis revealed that only 24 of the 1011 compounds have high similarity to the FDA-approved antiviral drugs, indicating that most of the compounds were structurally novel. Based on the predicted anti-SARS-CoV-2 compounds, we identified 74 anti-SARS-CoV-2 medicinal plants through enrichment analysis. The 74 plants are widely distributed in 68 genera and 43 families, 14 of which belong to antipyretic detoxicate plants. In summary, this study provided several medicinal plants with potential anti-SARS-CoV-2 activity, which offer an attractive starting point and a broader scope to mine for potentially novel anti-SARS-CoV-2 drugs.

Dissection of the Active Ingredients and Potential Mechanism of Han-Shi-Yu-Fei-Decoction in Treating COVID-19 Based on In Vivo Substances Profiling and Clinical Symptom-Guided Network Pharmacology

This work was aimed to elucidate the mechanism of action of Han-Shi-Yu-Fei-decoction (HSYFD) for treating patients with mild coronavirus disease 2019 (COVID-19) based on clinical symptom-guided network pharmacology. Experimentally, an ultra-high performance liquid chromatography technique coupled with quadrupole time-of-flight mass spectrometry method was used to profile the chemical components and the absorbed prototype constituents in rat serum after its oral administration, and 11 out of 108 compounds were identified. Calculatingly, the disease targets of Han-Shi-Yu-Fei symptoms of COVID-19 were constructed through the TCMIP V2.0 database. The subsequent network pharmacology and molecular docking analysis explored the molecular mechanism of the absorbed prototype constituents in the treatment of COVID-19. A total of 42 HSYFD targets oriented by COVID-19 clinical symptom were obtained, with EGFR, TP53, TNF, JAK2, NR3C1, TH, COMT, and DRD2 as the core targets. Enriched pathway analysis yielded multiple COVID-19-related signaling pathways, such as the PI3K/AKT signaling pathway and JAK-STAT pathway. Molecular docking showed that the key compounds, such as 6-gingerol, 10-gingerol, and scopoletin, had high binding activity to the core targets like COMT, JAK2, and NR3C1. Our work also verified the feasibility of clinical symptom-guided network pharmacology analysis of chemical compounds, and provided a possible agreement between the points of views of traditional Chinese medicine and western medicine on the disease.

Integrated network pharmacology analysis, molecular docking, LC-MS analysis and bioassays revealed the potential active ingredients and underlying mechanism of Scutellariae radix for COVID-19

Scutellariae radix ("Huang-Qin" in Chinese) is a well-known traditional herbal medicine and popular dietary supplement in the world, extensively used in prescriptions of TCMs as adjuvant treatments for coronavirus pneumonia 2019 (COVID-19) patients in China. According to the differences in its appearance, Scutellariae radix can be classified into two kinds: ZiQin (1∼3 year-old Scutellariae baicalensis with hard roots) and KuQin (more than 3 year-old S. baicalensis with withered pithy roots). In accordance with the clinical theory of TCM, KuQin is superior to ZiQin in cooling down the heat in the lung. However, the potential active ingredients and underlying mechanisms of Scutellariae radix for the treatment of COVID-19 remain largely unexplored. It is still not clear whether there is a difference in the curative effect of ZiQin and KuQin for the treatment of COVID-19. In this research, network pharmacology, LC-MS based plant metabolomics, and in vitro bioassays were integrated to explore both the potential active components and mechanism of Scutellariae radix for the treatment of COVID-19. As the results, network pharmacology combined with molecular docking analysis indicated that Scutellariae radix primarily regulates the MAPK and NF-κB signaling pathways via active components such as baicalein and scutellarin, and blocks SARS-CoV-2 spike binding to human ACE2 receptors. In vitro bioassays showed that baicalein and scutellarein exhibited more potent anti-inflammatory and anti-infectious effects than baicalin, the component with the highest content in Scutellariae radix. Moreover, baicalein inhibited SARS-CoV-2's entry into Vero E6 cells with an IC₅₀ value of 142.50 μM in a plaque formation assay. Taken together, baicalein was considered to be the most crucial active component of Scutellariae radix for the treatment of COVID-19 by integrative analysis. In addition, our bioassay study revealed that KuQin outperforms ZiQin in the treatment of COVID-19. Meanwhile, plant metabolomics revealed that baicalein was the compound with the most significant increase in KuQin compared to ZiQin, implying the primary reason for the superiority of KuQin over ZiQin in the treatment of COVID-19.

Construction of network pharmacology-based approach and potential mechanism from major components of Coriander sativum L. against COVID-19

Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. Despite the fact that various therapeutic compounds have shown potential prevention or treatment, no specific medicine has been developed for the COVID-19 pandemic. Natural products have recently been suggested as a possible treatment option for COVID-19 prevention and treatment. This study focused on the potential of Coriander sativum L. (CSL) against COVID-19 based on network pharmacology approach. Interested candidates of CSL were identified by searching accessible databases for protein–protein interactions with the COVID-19. An additional GO and KEGG pathway analysis was carried out in order to identify the related mechanism of action. In the end, 51 targets were obtained through network pharmacology analysis with EGFR, AR, JAK2, PARP1, and CTSB become the core target. CSL may have favorable effects on COVID-19 through a number of important pathways, according to GO and KEGG pathway analyses. These findings suggest that CSL may prevent and inhibit the several processes related to COVID-19.

Traditional Chinese medicine against COVID-19: Role of the gut microbiota

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and it has become a public health concern worldwide. In addition to respiratory symptoms, some COVID‑19 patients also show various gastrointestinal symptoms and even consider gastrointestinal symptoms to be the first manifestation. A large amount of evidence has shown that SARS-CoV-2 infection could disrupt the gut microbiota balance, and disorders of the gut microbiota could aggravate the condition of COVID-19 patients. Therefore, maintaining the gut microbiota balance is expected to become a potential new therapeutic target for treating COVID-19. Traditional Chinese medicine (TCM) has significant effects in all stages of the prevention and treatment of COVID-19. It can adjust the gut microbiota and is an ideal intestinal microecological regulator. This review summarizes the advantages and clinical efficacy of TCM in the treatment of COVID-19 and expounds on the relationship between TCM and the gut microbiota, the relationship between COVID-19 and the gut microbiota, the mechanism of gut microbiota disorders induced by SARS-CoV-2, the relationship between cytokine storms and the gut microbiota, and the role and mechanism of TCM in preventing and treating COVID-19 by regulating the gut microbiota to provide new research ideas for TCM in the prevention and treatment of COVID-19.

Transcriptional regulation and small compound targeting of ACE2 in lung epithelial cells

Angiotensin-converting enzyme 2 (ACE2) is the receptor of COVID-19 pathogen SARS-CoV-2, but the transcription factors (TFs) that regulate the expression of the gene encoding ACE2 (ACE2) have not been systematically dissected. In this study we evaluated TFs that control ACE2 expression, and screened for small molecule compounds that could modulate ACE2 expression to block SARS-CoV-2 from entry into lung epithelial cells. By searching the online datasets we found that 24 TFs might be ACE2 regulators with signal transducer and activator of transcription 3 (Stat3) as the most significant one. In human normal lung tissues, the expression of ACE2 was positively correlated with phosphorylated Stat3 (p-Stat3). We demonstrated that Stat3 bound ACE2 promoter, and controlled its expression in 16HBE cells stimulated with interleukin 6 (IL-6). To screen for medicinal compounds that could modulate ACE2 expression, we conducted luciferase assay using HLF cells transfected with ACE2 promoter-luciferase constructs. Among the 64 compounds tested, 6-O-angeloylplenolin (6-OAP), a sesquiterpene lactone in Chinese medicinal herb Centipeda minima (CM), represented the most potent ACE2 repressor. 6-OAP (2.5 µM) inhibited the interaction between Stat3 protein and ACE2 promoter, thus suppressed ACE2 transcription. 6-OAP (1.25-5 µM) and its parental medicinal herb CM (0.125%-0.5%) dose-dependently downregulated ACE2 in 16HBE and Beas-2B cells; similar results were observed in the lung tissues of mice following administration of 6-OAP or CM for one month. In addition, 6-OAP/CM dose-dependently reduced IL-6 production and downregulated chemokines including CXCL13 and CX3CL1 in 16HBE cells. Moreover, we found that 6-OAP/CM inhibited the entry of SARS-CoV-2 S protein pseudovirus into target cells. These results suggest that 6-OAP/CM are ACE2 inhibitors that may potentially protect lung epithelial cells from SARS-CoV-2 infection.

Gu-Ben-Zhi-Ke-Zhong-Yao Alleviated PM2.5-Induced Lung Injury via HMGB1/NF-κB Axis

Background

Inhalation of particles with a diameter of less than 2.5 μm (PM2.5) among air pollutants may cause lung damage. Gu-Ben-Zhi-Ke-Zhong-Yao (GBZK) is a traditional Chinese medicine prescription that has a beneficial effect on the treatment of chronic obstructive pulmonary disease (COPD). However, the effect of GBZK on PM2.5-induced lung injury remains to be elucidated.

Methods

We constructed a mice lung injury model through PM2.5 stimulation and simultaneously performed GBZK gavage treatment. After 4 weeks, the lung tissues of the mice were collected for pathological staining to analyze the degree of damage. The activities of myeloperoxidase (MPO), malondialdehyde (MDA), and oxidative stress-related factors (superoxide dismutase, SOD; glutathione peroxidase, GSH-Px) were detected by commercial kit in lung tissue. Furthermore, the number of neutrophils and related inflammatory factors (interleukin-1, IL-1β; tumor necrosis factor α, TNF-α; interleukin-6, IL-6) in bronchoalveolar lavage fluid (BALF) and serum were collected and tested to evaluate the effect of GBZK on inflammation. Masson staining was used to detect the level of lung fibrosis in mice. The activation of HMGB1 (high-mobility group protein 1) and NFκBp65 (nucleus factor kappa B) in lung tissue was evaluated by immunohistochemistry and western blot.

Results

The result revealed that PM2.5 induces lung damage, and GBZK gavage treatment could reduce the degree of injury in a concentration-dependent manner in mice. After GBZK treatment, the MPO activity, MDA content, and oxidative stress level in the lung tissues of mice decreased. And after GBZK treatment, the expression levels of inflammatory cytokines in BALF and blood were decreased. GBZK treatment also improved pulmonary fibrosis in mice. In addition, we also found that GBZK prevented the up-regulation of the HMGB1/NF-κB axis in the lungs of mice.

Conclusion

These results indicated that GBZK might protect mice from PM2.5-induced lung injury by inhibiting the HMGB1/NFκB pathway, thus repressing inflammation and pulmonary fibrosis.

Distribution, biotransformation, pharmacological effects, metabolic mechanism and safety evaluation of Platycodin D：A comprehensive review

Platycodonis Radix (Jiegeng), the dried root of Platycodon grandiflorum, is a traditional herb used as both medicine and food. Its clinical application for the treatment of cough, phlegm, sore throat, pulmonary and respiratory diseases has been thousands of years in China. Platycodin D is the main active ingredient in Platycodonis Radix, which belongs to the family of pentacyclic triterpenoid saponins because it contains an oleanolane type aglycone linked with double sugar chains. Modern pharmacology has demonstrated that Platycodin D displays various biological activities, such as analgesics, expectoration and cough suppression, promoting weight loss, anti-tumor and immune regulation, suggesting that Platycodin D has the potential to be a drug candidate and an interesting target as a natural product for clinical research. In this review, the distribution and biotransformation, pharmacological effects, metabolic mechanism and safety evaluation of Platycodin D are summarized to lay the foundation for further studies.