The Scientific Foundation of Chinese Herbal Medicine against COVID-19

Traditional Chinese Medicine as the Preventive and Therapeutic Remedy for COVID-19

The coronavirus disease 2019 (COVID-19) pandemic still has tremendous impacts on the global socio-economy and quality of living. The traditional Chinese Medicines (TCM) approach showed encouraging results during previous outbreaks of Severe Acute Respiratory Syndrome-related Coronavirus (SARS-CoV) and the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). With limited treatment availability, TCM herbs and formulations could be useful to reduce COVID-19 symptoms and potential sources for discovering novel therapeutic targets. We reviewed 12 TCM herbs and formulations recommended for COVID-19 management by the National Health Commission and as National Administration of Traditional Chinese Medicine of the People's Republic of China. This article explored the Chinese national authorities' guidelines from 2003 to 2020, the scientific data in public databases for the recommended TCM remedies, and their potential mechanistic actions in COVID-19 management. Several TCM herbs and formulations could potentially benefit COVID-19 management. The recommended TCM oral preparations list includes Huoxiang zhengqi, Jinhua Qinggan, Lianhua Qingwen, and Shufeng jiedu; the recommended injection preparations comprise Xiyanping Xuebijing, Re-Du-Ning, Tanreqing, Xingnaojing, Shenfu, Shengmai, and Shenmai. TCM remedies are viable options for symptom alleviation and management of COVID-19. The current SARS-CoV-2 pandemic presents an opportunity to find novel therapeutic targets from TCM-active ingredients. Despite the recommendations in Chinese National guidelines, these remedies warrant further assessments in well-designed clinical trials to ascertain their efficacy in the treatment of COVID-19.

Recent advances towards natural plants as potential inhibitors of SARS-Cov-2 targets

CONTEXT

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still ongoing and currently the most striking epidemic disease. With the rapid global spread of SARS-CoV-2 variants, new antivirals are urgently needed to avert a more serious crisis. Inhibitors from traditional medicines or natural plants have shown promising results to fight COVID-19 with different mechanisms of action.

OBJECTIVES

To provide comprehensive and promising approaches to the medical community in the fight against this epidemic by reviewing potential plant-derived anti-SARS-CoV-2 inhibitors.

METHODS

Structural databases such as TCMSP (http://lsp.nwu.edu.cn/tcmsp.php), TCM Database @ Taiwan (http://tcm.cmu.edu.tw/), BATMAN-TCM (http://bionet.ncpsb.org/batman-tcm/) and TCMID (http://www.megabionet.org/tcmid/), as well as PubMed, Sci Finder, Research Gate, Science Direct, CNKI, Web of Science and Google Scholar were searched for relevant articles on TCMs and natural products against SARS-CoV-2.

RESULTS

Seven traditional Chinese medicines formulas have unique advantages in regulating the immune system for treating COVID-19. The plant-derived natural compounds as anti-SARS-CoV-2 inhibitors were identified based on 5 SARS-CoV-2 key proteins, namely, angiotensin-converting enzyme 2 (ACE2), 3 C-like protease (3CLpro), papain-like protease (PLpro), spike (S) protein, and nucleocapsid (N) protein.

CONCLUSIONS

A variety of natural products, such as flavonoids, terpenoids, phenols, and alkaloids, were identified, which could be used as potential SASR-Cov-2 inhibitors. These shed new light on the efficient discovery of SASR-Cov-2 inhibitors from natural products.

Electrostatic Self-Assembly of MXene on Ruthenium Dioxide-Modified Carbon Cloth for Electrochemical Detection of Kaempferol

A superior composite material consisting of MXene and ruthenium dioxide-modified carbon cloth is synthesized by pulsed laser deposition and electrostatic self-assembly, which is further utilized to construct a class of novel electrochemical (EC) sensors for kaempferol (KA) detection. The carbon-cloth-based electrodes modified by ruthenium dioxide and then MXene are characterized by X-ray diffraction, scanning electron microscope, and X-ray photoemission spectroscopy. The EC process on the modified electrodes is analyzed by cyclic voltammetry, EC impedance spectroscopy, and differential pulse voltammetry. It is found that positively charged RuO2 not only possesses the remarkable electrical conductivity and electrocatalysis activity but also hampers the restacking of MXene, which accordingly enhances the exposure of the active surface area and greatly boosts the electrocatalysis activity of the entire composite. Consequently, this newly developed composite-based EC sensor exhibits a high sensitivity, selectivity, and remarkable stability to detect KA with two linear ranges of 0.06-1 and 1-15 µM. The inferred limit of detection is 0.039 µM via differential pulse voltammetry. More importantly, this novel EC sensor is found to be applicable for detecting KA in practical traditional Chinese medicines.

Biosynthesis and Pharmacological Activities of Flavonoids, Triterpene Saponins and Polysaccharides Derived from Astragalus membranaceus

Astragalus membranaceus (A. membranaceus), a well-known traditional herbal medicine, has been widely used in ailments for more than 2000 years. The main bioactive compounds including flavonoids, triterpene saponins and polysaccharides obtained from A. membranaceus have shown a wide range of biological activities and pharmacological effects. These bioactive compounds have a significant role in protecting the liver, immunomodulation, anticancer, antidiabetic, antiviral, antiinflammatory, antioxidant and anti-cardiovascular activities. The flavonoids are initially synthesized through the phenylpropanoid pathway, followed by catalysis with corresponding enzymes, while the triterpenoid saponins, especially astragalosides, are synthesized through the universal upstream pathways of mevalonate (MVA) and methylerythritol phosphate (MEP), and the downstream pathway of triterpenoid skeleton formation and modification. Moreover, the Astragalus polysaccharide (APS) possesses multiple pharmacological activities. In this review, we comprehensively discussed the biosynthesis pathway of flavonoids and triterpenoid saponins, and the structural features of polysaccharides in A. membranaceus. We further systematically summarized the pharmacological effects of bioactive ingredients in A. membranaceus, which laid the foundation for the development of clinical candidate agents. Finally, we proposed potential strategies of heterologous biosynthesis to improve the industrialized production and sustainable supply of natural products with pharmacological activities from A. membranaceus, thereby providing an important guide for their future development trend.

Characteristics and result reporting of registered COVID-19 clinical trials of Chinese and Indian traditional medicine: A comparative analysis

Objective

To assess the main characteristics and result reporting of registered COVID-19 interventional trials of traditional Chinese medicine and traditional Indian medicine.

Materials and methods

We assessed design quality and result reporting of COVID-19 trials of traditional Chinese medicine (TCM) and traditional Indian medicine (TIM) registered before 10 February 2021, respectively, on Chinese Clinical Trial Registry (ChiCTR) and Clinical Trial Registry-India (CTRI). Comparison groups included registered COVID-19 trials of conventional medicine conducted in China (WMC), India (WMI), and in other countries (WMO). Cox regression analysis was used to assess the association between time from trial onset to result reporting and trial characteristics.

Results

The proportion of COVID-19 trials investigating traditional medicine was 33.7% (130/386) among trials registered on ChiCTR, and 58.6% (266/454) on CTRI. Planned sample sizes were mostly small in all COVID-19 trials (median 100, IQR: 50-200). The proportion of trials that were randomized was 75.4 and 64.8%, respectively, for the TCM and TIM trials. Blinding measures were used in 6.2% of the TCM trials, and 23.6% of the TIM trials. Cox regression analysis revealed that planned COVID-19 clinical trials of traditional medicine were less likely to have results reported than trials of conventional medicine (hazard ratio 0.713, 95% confidence interval: 0.541-0.939; p = 0.0162).

Conclusion

There were considerable between-country and within-country differences in design quality, target sample size, trial participants, and reporting of trial results. Registered COVID-19 clinical trials of traditional medicine were less likely to report results than trials of conventional medicine.

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

Traditional Chinese medicine (TCM) has been successfully applied worldwide in the treatment of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the pharmacological mechanisms underlying this success remain unclear. Hence, the aim of this review is to combine pharmacological assays based on the theory of TCM in order to elucidate the potential signaling pathways, targets, active compounds, and formulas of herbs that are involved in the TCM treatment of COVID-19, which exhibits combatting viral infections, immune regulation, and amelioration of lung injury and fibrosis. Extensive reports on target screening are elucidated using virtual prediction via docking analysis or network pharmacology based on existing data. The results of these reports indicate that an intricate regulatory mechanism is involved in the pathogenesis of COVID-19. Therefore, more pharmacological research on the natural herbs used in TCM should be conducted in order to determine the association between TCM and COVID-19 and account for the observed therapeutic effects of TCM against COVID-19.

The draft genome and multi-omics analyses reveal new insights into geo-herbalism properties of Citrus grandis 'Tomentosa'

Citrus grandis 'Tomentosa' (CGT) (Huajuhong, HJH) is a widely used medicinal plant, which is mainly produced in Guangdong and Guangxi provinces of South China. Particularly, HJH from Huazhou (HZ) county of Guangdong province has been well-regarded as the best national product for geo-herbalism. But the reasons for geo-herbalism property in HJH from HZ county remains a mystery. Therefore, a multi-omics approach was applied to identify the nature of the geo-herbalism in CGT from three different regions. The comprehensive screening of differential metabolites revealed that the Nobiletin content was significantly different in HZ region compared to other regions, and could be employed as a key indicator to determine the geo-herbalism. Furthermore, the high-quality genome (N50 of 9.12 Mb), coupled with genomics and transcriptomics analyses indicated that CGT and Citrus grandis are closely related, with a predicted divergence time of 19.1 million years ago (MYA), and no recent WGD occurred in the CGT, and the bioactive ingredients of CGT were more abundant than that of Citrus grandis. Interestingly, Nobiletin (Polymethoxyflavones) content was identified as a potential indicator of geo-herbalism, and O-methyltransferase (OMT) genes are involved in the synthesis of Polymethoxyflavones. Further multi-omics analysis led to the identification of a novel OMT gene (CtgOMT1) whose transient overexpression displayed significantly higher Nobiletin content, suggesting that CtgOMT1 was involved in the synthesis of Nobiletin. Overall, our findings provide new data resources for geo-herbalism evaluation, germplasm conservation and insights into Nobiletin biosynthesis pathways for the medicinal plant C. grandis 'Tomentosa'.

Multi-omics approaches for in-depth understanding of therapeutic mechanism for Traditional Chinese Medicine

Traditional Chinese Medicine (TCM) is extensively utilized in clinical practice due to its therapeutic and preventative treatments for various diseases. With the development of high-throughput sequencing and systems biology, TCM research was transformed from traditional experiment-based approaches to a combination of experiment-based and omics-based approaches. Numerous academics have explored the therapeutic mechanism of TCM formula by omics approaches, shifting TCM research from the "one-target, one-drug" to "multi-targets, multi-components" paradigm, which has greatly boosted the digitalization and internationalization of TCM. In this review, we concentrated on multi-omics approaches in principles and applications to gain a better understanding of TCM formulas against various diseases from several aspects. We first summarized frequently used TCM quality assessment methods, and suggested that incorporating both chemical and biological ingredients analytical methods could lead to a more comprehensive assessment of TCM. Secondly, we emphasized the significance of multi-omics approaches in deciphering the therapeutic mechanism of TCM formulas. Thirdly, we focused on TCM network analysis, which plays a vital role in TCM-diseases interaction, and serves for new drug discovery. Finally, as an essential source for storing multi-omics data, we evaluated and compared several TCM databases in terms of completeness and reliability. In summary, multi-omics approaches have infiltrated many aspects of TCM research. With the accumulation of omics data and data-mining resources, deeper understandings of the therapeutic mechanism of TCM have been acquired or will be gained in the future.

Role and molecular mechanism of traditional Chinese medicine in preventing cardiotoxicity associated with chemoradiotherapy

Cardiotoxicity is a serious complication of cancer therapy. It is the second leading cause of morbidity and mortality in cancer survivors and is associated with a variety of factors, including oxidative stress, inflammation, apoptosis, autophagy, endoplasmic reticulum stress, and abnormal myocardial energy metabolism. A number of studies have shown that traditional Chinese medicine (TCM) can mitigate chemoradiotherapy-associated cardiotoxicity via these pathways. Therefore, this study reviews the effects and molecular mechanisms of TCM on chemoradiotherapy-related cardiotoxicity. In this study, we searched PubMed for basic studies on the anti-cardiotoxicity of TCM in the past 5 years and summarized their results. Angelica Sinensis, Astragalus membranaceus Bunge, Danshinone IIA sulfonate sodium (STS), Astragaloside (AS), Resveratrol, Ginsenoside, Quercetin, Danggui Buxue Decoction (DBD), Shengxian decoction (SXT), Compound Danshen Dripping Pill (CDDP), Qishen Huanwu Capsule (QSHWC), Angelica Sinensis and Astragalus membranaceus Bunge Ultrafiltration Extract (AS-AM),Shenmai injection (SMI), Xinmailong (XML), and nearly 60 other herbs, herbal monomers, herbal soups and herbal compound preparations were found to be effective as complementary or alternative treatments. These preparations reduced chemoradiotherapy-induced cardiotoxicity through various pathways such as anti-oxidative stress, anti-inflammation, alleviating endoplasmic reticulum stress, regulation of apoptosis and autophagy, and improvement of myocardial energy metabolism. However, few clinical trials have been conducted on these therapies, and these trials can provide stronger evidence-based support for TCM.

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.

The SARS-CoV-2 main protease (Mpro): Structure, function, and emerging therapies for COVID-19

The main proteases (Mpro), also termed 3-chymotrypsin-like proteases (3CLpro), are a class of highly conserved cysteine hydrolases in β-coronaviruses. Increasing evidence has demonstrated that 3CLpros play an indispensable role in viral replication and have been recognized as key targets for preventing and treating coronavirus-caused infectious diseases, including COVID-19. This review is focused on the structural features and biological function of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease Mpro (also known as 3CLpro), as well as recent advances in discovering and developing SARS-CoV-2 3CLpro inhibitors. To better understand the characteristics of SARS-CoV-2 3CLpro inhibitors, the inhibition activities, inhibitory mechanisms, and key structural features of various 3CLpro inhibitors (including marketed drugs, peptidomimetic, and non-peptidomimetic synthetic compounds, as well as natural compounds and their derivatives) are summarized comprehensively. Meanwhile, the challenges in this field are highlighted, while future directions for designing and developing efficacious 3CLpro inhibitors as novel anti-coronavirus therapies are also proposed. Collectively, all information and knowledge presented here are very helpful for understanding the structural features and inhibitory mechanisms of SARS-CoV-2 3CLpro inhibitors, which offers new insights or inspiration to medicinal chemists for designing and developing more efficacious 3CLpro inhibitors as novel anti-coronavirus agents.

Role of Traditional Chinese Medicine in Treating Severe or Critical COVID-19: A Systematic Review of Randomized Controlled Trials and Observational Studies

Background: The coronavirus disease 2019 (COVID-19) continues to spread globally. Due to the higher risk of mortality, the treatment of severe or critical patients is a top priority. Traditional Chinese medicine (TCM) treatment has played an extremely important role in the fight against COVID-19 in China; a timely evidence summary on TCM in managing COVID-19 is crucial to update the knowledge of healthcare for better clinical management of COVID-19. This study aimed to assess the effects and safety of TCM treatments for severe/critical COVID-19 patients by systematically collecting and synthesizing evidence from randomized controlled trials (RCTs) and observational studies (e.g., cohort).

Methods: We searched nine databases up to 19th March 2022 and the reference lists of relevant publications. Pairs of reviewers independently screened studies, extracted data of interest, and assessed risk of bias. We performed qualitative systematic analysis with visual presentation of results and compared the direction and distribution of effect estimates for each patient’s important outcome. We performed sensitivity analyses to observe the robustness of results by restricting analysis to studies with low risk of bias.

Results: The search yielded 217,761 records, and 21 studies (6 RCTs and 15 observational studies) proved eligible. A total of 21 studies enrolled 12,981 severe/critical COVID-19 patients with a mean age of 57.21 years and a mean proportion of men of 47.91%. Compared with usual supportive treatments, the effect estimates of TCM treatments were consistent in direction, illustrating that TCM treatments could reduce the risk of mortality, rate of conversion to critical cases, and mechanical ventilation, and showed significant advantages in shortening the length of hospital stay, time to viral clearance, and symptom resolution. The results were similar when we restricted analyses to low-risk-bias studies. No serious adverse events were reported with TCM treatments, and no significant differences were observed between groups.

Conclusion: Encouraging evidence suggests that TCM presents substantial advantages in treating severe/critical COVID-19 patients. TCM has a safety profile that is comparable to that of conventional treatment alone. TCMs have played an important role in China’s prevention and treatment of COVID-19, which sets an example of using traditional medicine in preventing and treating COVID-19 worldwide.

Promoting the Development of Astragalus mongholicus Bunge Industry in Guyang County (China) Based on MaxEnt and Remote Sensing

To provide high-quality Astragalus mongholicus Bunge to domestic and foreign markets and maintain sustainable development of the A. mongholicus industry, Firstly, we evaluated the impact of environmental factors and planting areas on the A. mongholicus industry. The maximum entropy method (MaxEnt) was utilized to simulate the suitability distribution of A. mongholicus and establish the relationship between the active component contents of A. mongholicus and ecological factors through linear regression analysis. The random forest algorithm was subsequently used to perform feature selection and classification extraction on Sentinel-2 imagery covering the study area. Furthermore, the planting, processing, and sales of A. mongholicus in Guyang County were investigated, and the roles of stakeholders in the value chains were analyzed. The results demonstrated that precipitation of the warmest quarter, minimum temperature of the coldest month, standard deviation of seasonal temperature changes, range of mean annual temperature, and mean diurnal range [mean of monthly (max temp - min temp)] were the five environmental variables that contributed the most to the growth of A. mongholicus. The most influential factor on the distribution of high-quality A. mongholicus was the mean temperature of the coldest quarter. The classification results of image features showed that the planting areas of A. mongholicus was consistent with the suitable planting areas predicted by MaxEnt, which can provide data support to the relevant departments for the macro development of the A. mongholicus industry. In the production of A. mongholicus, 10 value chains were constructed, and the study demonstrated that the behavior of stakeholders, target markets, and the selected planting area had a significant impact on the quality of A. mongholicus.

Chromosome-level and haplotype-resolved genome provides insight into the tetraploid hybrid origin of patchouli

Patchouli (Pogostemon cablin (Blanco) Benth.), a member of the Lamiaceae family, is an important aromatic plant that has been widely used in medicine and perfumery. Here, we report a 1.94 Gb chromosome-scale assembly of the patchouli genome (contig N50 = 7.97 Mb). The gene annotation reveals that tandem duplication of sesquiterpene biosynthetic genes may be a major contributor to the biosynthesis of patchouli bioactivity components. We further phase the genome into two distinct subgenomes (A and B), and identify a chromosome substitution event that have occurred between them. Further investigations show that a burst of universal LTR-RTs in the A subgenome lead to the divergence between two subgenomes. However, no significant subgenome dominance is detected. Finally, we track the evolutionary scenario of patchouli including whole genome tetraploidization, subgenome divergency, hybridization, and chromosome substitution, which are the key forces to determine the complexity of patchouli genome. Our work sheds light on the evolutionary history of patchouli and offers unprecedented genomic resources for fundamental patchouli research and elite germplasm development.

The ploidy level of patchouli, an aromatic plant in the Lamiaceae family, remain unclear. Here, the authors assemble a chromosome-level and haplotype-resolved genome for patchouli and reveal that it is tetraploid hybrid as well as compensated aneuploidy.

Favipiravir for the treatment of COVID-19 in elderly patients-what do we know after 2 years of COVID-19?

Since the appearance of coronavirus disease 2019 (COVID-19), numerous studies have been conducted to find effective therapeutics. Favipiravir (FVP) is one of the repurposed drugs which has been authorized in a few countries on an emergency basis to treat COVID-19. Elderly individuals especially 65 years or older are more prone to develop severe illness. We aim to provide a short summary of the current knowledge of the antiviral efficacy of favipiravir with respect to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected elderly patients. We found that it is rather controversial whether favipiravir is effective against SARS-CoV-2 infection. Data regarding patients 65 years or older is not sufficient to support or reject the usage of favipiravir for COVD-19 treatment. Further studies would be advisable to elicit the efficiency of favipiravir in elderly COVID-19 patients.

Sinapic acid inhibits pancreatic cancer proliferation, migration, and invasion via downregulation of the AKT/Gsk-3β signal pathway

Among digestive system cancers, the extremely poor prognosis of pancreatic cancer (PC) is a pressing concern. Nonoperative treatments such as targeted and immunotherapy, have improved the current situation, however, the accompanying side effects of these chemicals should not be ignored. Here, we discovered a novel hydroxycinnamic acid named sinapic acid (SA) derived from fruits, vegetables, cereals, and oil crops as an effective anti-PC molecule. Both the in vitro and in vivo models we designed showed that SA exhibited anticancer activities but not apoptosis induction. Research on the underlying mechanisms illustrated that AKT phosphorylation was blocked by SA, and the downstream Gsk-3β was downregulated subsequently. Our study revealed the inhibitory activity and underlying mechanisms of SA, providing evidence that SA is a potential strategy for cancer research and can be a promising option of PC chemotherapy.

Leveraging knowledge of Asian herbal medicine and its active compounds as COVID-19 treatment and prevention

The outbreak of COVID-19 disease has led to a search for effective vaccines or drugs. However, insufficient vaccine supplies to meet global demand and no effective approved prescribed drugs for COVID-19 have led some people to consider the use of alternative or complementary medicines, such as traditional herbal medicine. Medicinal plants have various therapeutic properties that depend on the active compounds they contain. Obviously, herbal medicine has had an essential role in treatment and prevention during COVID-19 outbreak, especially in Asian cultures. Hence, we reviewed the uses of herbal medicine in Asian cultures and described the prominent families and species that are sources of antiviral agents against COVID-19 on the basis of case reports, community surveys, and guidelines available in the literature databases. Antiviral efficacy as determined in laboratory testing was assessed, and several promising active compounds with their molecular targets in cell models against SARS-CoV-2 viral infection will be discussed. Our review findings revealed the highly frequent use of Lamiaceae family members, Zingiber officinale, and Glycyrrhiza spp. as medicinal sources for treatment of COVID-19. In addition, several plant bioactive compounds derived from traditional herbal medicine, including andrographolide, panduratin A, baicalein, digoxin, and digitoxin, have shown potent SARS-CoV-2 antiviral activity as compared with some repurposed FDA-approved drugs. These commonly used plants and promising compounds are recommended for further exploration of their safety and efficacy against COVID-19.

DNA aptamers masking angiotensin converting enzyme 2 as an innovative way to treat SARS-CoV-2 pandemic

All the different coronavirus SARS-CoV-2 variants isolated so far share the same mechanism of infection mediated by the interaction of their spike (S) glycoprotein with specific residues on their cellular receptor: the angiotensin converting enzyme 2 (ACE2). Therefore, the steric hindrance on this cellular receptor created by a bulk macromolecule may represent an effective strategy for the prevention of the viral spreading and the onset of severe forms of Corona Virus disease 19 (COVID-19). Here, we applied a systematic evolution of ligands by exponential enrichment (SELEX) procedure to identify two single strand DNA molecules (aptamers) binding specifically to the region surrounding the K353, the key residue in human ACE2 interacting with the N501 amino acid of the SARS-CoV-2 S. 3D docking in silico experiments and biochemical assays demonstrated that these aptamers bind to this region, efficiently prevent the SARS-CoV-2 S/human ACE2 interaction and the viral infection in the nanomolar range, regardless of the viral variant, thus suggesting the possible clinical development of these aptamers as SARS-CoV-2 infection inhibitors. Our approach brings a significant innovation to the therapeutic paradigm of the SARS-CoV-2 pandemic by protecting the target cell instead of focusing on the virus; this is particularly attractive in light of the increasing number of viral mutants that may potentially escape the currently developed immune-mediated neutralization strategies.

Traditional Chinese medicine in COVID-19

COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread across the globe, posing an enormous threat to public health and safety. Traditional Chinese medicine (TCM), in combination with Western medicine (WM), has made important and lasting contributions in the battle against COVID-19. In this review, updated clinical effects and potential mechanisms of TCM, presented in newly recognized three distinct phases of the disease, are summarized and discussed. By integrating the available clinical and preclinical evidence, the efficacies and underlying mechanisms of TCM on COVID-19, including the highly recommended three Chinese patent medicines and three Chinese medicine formulas, are described in a panorama. We hope that this comprehensive review not only provides a reference for health care professionals and the public to recognize the significant contributions of TCM for COVID-19, but also serves as an evidence-based in-depth summary and analysis to facilitate understanding the true scientific value of TCM.

Determination of the interaction between the receptor binding domain of 2019-nCoV spike protein, TMPRSS2, cathepsin B and cathepsin L, and glycosidic and aglycon forms of some flavonols

The novel coronavirus (COVID-19, SARS-CoV-2) is a rapidly spreading disease with a high mortality. In this research, the interactions between specific flavonols and the 2019-nCoV receptor binding domain (RBD), transmembrane protease, serine 2 (TMPRSS2), and cathepsins (CatB and CatL) were analyzed. According to the relative binding capacity index (RBCI) calculated based on the free energy of binding and calculated inhibition constants, it was determined that robinin (ROB) and gossypetin (GOS) were the most effective flavonols on all targets. While the binding free energy of ROB with the spike glycoprotein RBD, TMPRSS2, CatB, and CatL were -5.02, -7.57, -10.10, and -6.11 kcal/mol, the values for GOS were -4.67, -5.24, -8.31, and -6.76, respectively. Furthermore, both compounds maintained their stability for at least 170 ns on respective targets in molecular dynamics simulations. The molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations also corroborated these data. Considering Lipinski's rule of five, ROB and GOS exhibited 3 (MW>500, N or O>10, NH or OH>5), and 1 (NH or OH>5) violations, respectively. Neither ROB nor GOS showed AMES toxicity or hepatotoxicity. The LD50 of these compounds in rats were 2.482 and 2.527 mol/kg, respectively. Therefore, we conclude that these compounds could be considered as alternative therapeutic agents in the treatment of COVID-19. However, the possible inhibitory effects of these compounds on cytochromes (CYPs) should be verified by in vitro or in vivo tests and their adverse effects on cellular energy metabolism should be minimized by performing molecular modifications if necessary.

Chinese herbal medicine: Fighting SARS-CoV-2 infection on all fronts

ETHNOPHARMACOLOGICAL RELEVANCE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), a highly pathogenic virus that has spread rapidly across the entire world. There is a critical need to develop safe and effective drugs, especially broad-spectrum antiviral and organ protection agents in order to treat and prevent this dangerous disease. It is possible that Chinese herbal medicine may play an essential role in the treatment of patients with SARS-CoV-2 infection.

AIM OF THE REVIEW

We aim to review the use of Chinese herbal medicine in the treatment of COVID-19 both in vitro and in clinical practice. Our goal was to provide a better understanding of the potential therapeutic effects of Chinese herbal medicine and to establish a "Chinese protocol" for the treatment of COVID-19.

MATERIALS AND METHODS

We systematically reviewed published research relating to traditional Chinese herbal medicines and the treatment of SARS-CoV-2 from inception to the 6^th January 2021 by screening a range of digital databases (Web of Science, bioRxiv, medRxiv, China National Knowledge Infrastructure, X-MOL, Wanfang Data, Google Scholar, PubMed, Elsevier, and other resources) and public platforms relating to the management of clinical trials. We included the active ingredients of Chinese herbal medicines, monomer preparations, crude extracts, and formulas for the treatment of COVID-19.

RESULTS

In mainland China, a range of Chinese herbal medicines have been recognized as very promising anti-SARS-CoV-2 agents, including active ingredients (quercetagetin, osajin, tetrandrine, proscillaridin A, and dihydromyricetin), monomer preparations (xiyanping injection, matrine-sodium chloride injection, diammonium glycyrrhizinate enteric-coated capsules, and sodium aescinate injection), crude extracts (Scutellariae Radix extract and garlic essential oil), and formulas (Qingfei Paidu decoction, Lianhuaqingwen capsules, and Pudilan Xiaoyan oral liquid). All these agents have potential activity against SARS-CoV-2 and have attracted significant attention due to their activities both in vitro and in clinical practice.

CONCLUSIONS

As a key component of the COVID-19 treatment regimen, Chinese herbal medicines have played an irreplaceable role in the treatment of SARS-CoV-2 infection. The "Chinese protocol" has already demonstrated clear clinical importance. The use of Chinese herbal medicines that are capable of inhibiting SARS-Cov-2 infection may help to address this immediate unmet clinical need and may be attractive to other countries that are also seeking new options for effective COVID-19 treatment. Our analyses suggest that countries outside of China should also consider protocols involving Chinese herbal medicines combat this fast-spreading viral infection.

Dynamic changes in fibrinogen and D-dimer levels in COVID-19 patients on nafamostat mesylate

Critical illnesses associated with coronavirus disease 2019 (COVID-19) are attributable to a hypercoagulable status. There is limited knowledge regarding the dynamic changes in coagulation factors among COVID-19 patients on nafamostat mesylate, a potential therapeutic anticoagulant for COVID-19. First, we retrospectively conducted a cluster analysis based on clinical characteristics on admission to identify latent subgroups among fifteen patients with COVID-19 on nafamostat mesylate at the University of Tokyo Hospital, Japan, between April 6 and May 31, 2020. Next, we delineated the characteristics of all patients as well as COVID-19-patient subgroups and compared dynamic changes in coagulation factors among each subgroup. The subsequent dynamic changes in fibrinogen and D-dimer levels were presented graphically. All COVID-19 patients　were classified into three subgroups: clusters A, B, and C, representing low, intermediate, and high risk of poor outcomes, respectively. All patients were alive 30 days from symptom onset. No patient in cluster A required mechanical ventilation; however, all patients in cluster C required mechanical ventilation, and half of them were treated with venovenous extracorporeal membrane oxygenation. All patients in cluster A maintained low D-dimer levels, but some critical patients in clusters B and C showed dynamic changes in fibrinogen and D-dimer levels. Although the potential of nafamostat mesylate needs to be evaluated in randomized clinical trials, admission characteristics of patients with COVID-19 could predict subsequent coagulopathy.

COVID-19: Before the Fall, An Evidence-Based Narrative Review of Treatment Options

The 2019 novel coronavirus (COVID-19) has quickly become one of the most dire international pandemic crises since the 1918 Spanish flu. Evidence for COVID-19 pharmacological therapies has shown rapid growth and a diverse array of results, but an assessment of the value of each piece of evidence must be reinforced. This article aims to review utilized therapies, the evidence level supporting these therapies, as well as drugs under investigation for the treatment of COVID-19. Primary scrutinized therapies include antiviral regimens, such as remdesivir, hydroxychloroquine/chloroquine, lopinavir/ritonavir, immunomodulating drugs, such as corticosteroids and interleukin (IL) inhibitors, and other therapies including convalescent plasma. Only one therapy, dexamethasone, has shown a mortality benefit in randomized controlled trials and summarized evidence for other therapies show limited positive results. Reviewing these therapies in a historical way shows how limited evidence can drive therapy decisions. A broad summary of available evidence can assist clinicians in a return to hierarchical assessments of evidence which can lead to safer patient outcomes, improved distribution of resources, and better targets for appropriate therapy decisions.

Molecular dynamics simulation perception study of the binding affinity performance for main protease of SARS-CoV-2

Like common cold and flu, SARC-CoV-2 virus spreads by droplets of sneezes or coughs which virus affects people of various age groups. Today, this virus is almost distributed all over the world. Since binding process plays a crucial role between host and receptor, therefore, we studied the molecules intended toward inhibition process through molecular docking and molecular dynamics simulation process. From the molecular docking study, it is noteworthy that remdesivir shows better binding affinity toward the main protease of SARS-CoV2 compared to other studied drugs. Within studied phytochemicals, carnosic acid shows better binding poses toward main protease of SARS-CoV2 among studied phytochemicals. The amino acid residues GLN110 and PHE294 were almost found in all the studied interactions of drugs and phytochemicals with main protease of SARS-CoV-2. Furthermore, the results show a larger contribution of the Van der Waals energies as compared to others like electrostatic energies suggesting that ligands at the binding pocket are predominantly stabilized by hydrophobic interactions. The conformational change during ligand binding was predicted from Gibbs free energy landscape analysis through molecular dynamics simulation. We observed that, there were two main free energy basins for both docked carnosic acid complex and for docked remdesivir complex, only one main free energy basin was found in the global free energy minimum region.

Communicated by Ramaswamy H. Sarma