The Role of Surveillance Inspections in Reducing False-Positives of SARS-CoV-2 Omicron Variants during the COVID-19 Epidemic.

Objective: This study aims to assess the effectiveness of surveillance inspections conducted by the provincial health committee in Quanzhou city during a COVID-19 outbreak in reducing false-positive results in SARS-CoV-2 RT-PCR assays. Method: The team conducted on-site inspections of laboratories that participated in mass screening, recording any violations of rules. Results: The positive cases in five rounds of mass screening were 23, 173, and 4 in Licheng District, Fengze District, and Luojang District, respectively. The false-positive rates in the five rounds of mass screening were 0.0099%, 0.0063%, 0.0018%, 0.0006%, and 0%, respectively. The study also recorded that the number of violations in the seven selected laboratories was 36, 68, 69, 42, 60, 54 and 47. The corresponding false-positive rates were 0.0012%, 0.0060%, 0.0082%, 0.0032%, 0.0060%, 0.0027%, and 0.0021%, respectively. The study found a positive correlation between false-positive rates and the number of violations (r = 0.905, P=0.005), and an inverse correlation between false-positive rates and the frequency of surveillance inspections (r = -0.950, P < 0.001). Conclusion: Daily surveillance inspection in laboratories can remind laboratories to strictly comply with standard procedures, focus on laboratory quality control, and reduce the occurrence of false-positive cases in SARS-CoV-2 nucleic acid tests to some extent. This study recommends that government decision-making departments establish policies and arrange experts to conduct daily surveillance inspections to improve laboratory quality control.

[Exploration and example interpretation of real-world herbal prescription classification based on similarity matching algorithm].

In observational studies, herbal prescriptions are usually studied in the form of "similar prescriptions". At present, the classification of prescriptions is mainly based on clinical experience judgment, but there are some problems in manual judgment, such as lack of unified criteria, labor consumption, and difficulty in verification. In the construction of a database of integrated traditional Chinese and western medicine for the treatment of coronavirus disease 2019(COVID-19), our research group tried to classify real-world herbal prescriptions using a similarity matching algorithm. The main steps include 78 target prescriptions are determined in advance; four levels of importance labeling shall be carried out for the drugs of each target prescription; the combination, format conversion, and standardization of drug names of the prescriptions to be identified in the herbal medicine database; calculate the similarity between the prescriptions to be identified and each target prescription one by one; prescription discrimination is performed based on the preset criteria; remove the name of the prescriptions with "large prescriptions cover the small". Through the similarity matching algorithm, 87.49% of the real prescriptions in the herbal medicine database of this study can be identified, which preliminarily proves that this method can complete the classification of herbal prescriptions. However, this method does not consider the influence of herbal dosage on the results, and there is no recognized standard for the weight of drug importance and criteria, so there are some limitations, which need to be further explored and improved in future research.

Therapeutic drug combinations against COVID-19 obtained by employing a collaborative filtering method

The outbreak of coronavirus disease 2019 (COVID-19) has severely harmed human society and health. Because there is currently no specific drug for the treatment and prevention of COVID-19, we used a collaborative filtering algorithm to predict which traditional Chinese medicines (TCMs) would be effective in combination for the prevention and treatment of COVID-19. First, we performed drug screening based on the receptor structure prediction method, molecular docking using q-vina to measure the binding ability of TCMs, TCM formulas, and neo-coronavirus proteins, and then performed synergistic filtering based on Laplace matrix calculations to predict potentially effective TCM formulas. Combining the results of molecular docking and synergistic filtering, the new recommended formulas were analyzed by reviewing data platforms or tools such as PubMed, Herbnet, the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, the Guide to the Dispensing of Medicines for Clinical Evidence, and the Dictionary of Chinese Medicine Formulas, as well as medical experts' treatment consensus in terms of herbal efficacy, modern pharmacological studies, and clinical identification and typing of COVID-19 pneumonia, to determine the recommended solutions. We found that the therapeutic effect of a combination of six TCM formulas on the COVID-19 virus is the result of the overall effect of the formula rather than that of specific components of the formula. Based on this, we recommend a formula similar to that of Jinhua Qinggan Granules for the treatment of COVID-19 pneumonia. This study may provide new ideas and new methods for future clinical research. Classification Biological Science.

A new framework for host-pathogen interaction research.

COVID-19 often manifests with different outcomes in different patients, highlighting the complexity of the host-pathogen interactions involved in manifestations of the disease at the molecular and cellular levels. In this paper, we propose a set of postulates and a framework for systematically understanding complex molecular host-pathogen interaction networks. Specifically, we first propose four host-pathogen interaction (HPI) postulates as the basis for understanding molecular and cellular host-pathogen interactions and their relations to disease outcomes. These four postulates cover the evolutionary dispositions involved in HPIs, the dynamic nature of HPI outcomes, roles that HPI components may occupy leading to such outcomes, and HPI checkpoints that are critical for specific disease outcomes. Based on these postulates, an HPI Postulate and Ontology (HPIPO) framework is proposed to apply interoperable ontologies to systematically model and represent various granular details and knowledge within the scope of the HPI postulates, in a way that will support AI-ready data standardization, sharing, integration, and analysis. As a demonstration, the HPI postulates and the HPIPO framework were applied to study COVID-19 with the Coronavirus Infectious Disease Ontology (CIDO), leading to a novel approach to rational design of drug/vaccine cocktails aimed at interrupting processes occurring at critical host-coronavirus interaction checkpoints. Furthermore, the host-coronavirus protein-protein interactions (PPIs) relevant to COVID-19 were predicted and evaluated based on prior knowledge of curated PPIs and domain-domain interactions, and how such studies can be further explored with the HPI postulates and the HPIPO framework is discussed.

Therapeutic drug combinations against COVID-19 obtained by employing a collaborative filtering method.

The outbreak of coronavirus disease 2019 (COVID-19) has severely harmed human society and health. Because there is currently no specific drug for the treatment and prevention of COVID-19, we used a collaborative filtering algorithm to predict which traditional Chinese medicines (TCMs) would be effective in combination for the prevention and treatment of COVID-19. First, we performed drug screening based on the receptor structure prediction method, molecular docking using q-vina to measure the binding ability of TCMs, TCM formulas, and neo-coronavirus proteins, and then performed synergistic filtering based on Laplace matrix calculations to predict potentially effective TCM formulas. Combining the results of molecular docking and synergistic filtering, the new recommended formulas were analyzed by reviewing data platforms or tools such as PubMed, Herbnet, the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, the Guide to the Dispensing of Medicines for Clinical Evidence, and the Dictionary of Chinese Medicine Formulas, as well as medical experts' treatment consensus in terms of herbal efficacy, modern pharmacological studies, and clinical identification and typing of COVID-19 pneumonia, to determine the recommended solutions. We found that the therapeutic effect of a combination of six TCM formulas on the COVID-19 virus is the result of the overall effect of the formula rather than that of specific components of the formula. Based on this, we recommend a formula similar to that of Jinhua Qinggan Granules for the treatment of COVID-19 pneumonia. This study may provide new ideas and new methods for future clinical research. Classification: Biological Science.

Controllable self-replicating RNA vaccine delivered intradermally elicits predominantly cellular immunity.

Intradermal delivery of self-replicating RNA (srRNA) is a promising vaccine platform. We have developed an srRNA that functions optimally at around 33°C (skin temperature) and is inactivated at or above 37°C (core body temperature) as a safety switch. This temperature-controllable srRNA (c-srRNA), when tested as an intradermal vaccine against SARS-CoV-2, functions when injected naked without lipid nanoparticles. Unlike most currently available vaccines, c-srRNA vaccines predominantly elicit cellular immunity with little or no antibody production. Interestingly, c-srRNA-vaccinated mice produced antigen-specific antibodies upon subsequent stimulation with antigen protein. Antigen-specific antibodies were also produced when B cell stimulation using antigen protein was followed by c-srRNA booster vaccination. We have thus designed a pan-coronavirus booster vaccine that incorporates both spike-receptor-binding domains as viral surface proteins and evolutionarily conserved nucleoproteins as viral internal proteins, from both severe acute respiratory syndrome coronavirus 2 and Middle East respiratory syndrome coronavirus. c-srRNA may provide a route to activate cellular immunity against a wide variety of pathogens.

Defining conversion therapy for esophageal squamous cell carcinoma.

A multimodality treatment conference with experts from across East Asia was held to establish a consensus for conversion therapy. An agreement was reached that conversion therapy was defined as surgery or chemoradiotherapy (CRT) aiming at cure after initial treatment for tumors that were initially unresectable due to adjacent organ invasion or distant metastasis.

Effect of wearing medical protective masks on treadmill running performance in the postpandemic era: a randomised trial.

BACKGROUND: In the postpandemic era, wearing protective masks in public places will still be an important means of blocking popular viruses in the future. The purpose of this study was to explore whether sports performance was affected by mask wearing and exercise duration during 15-min treadmill running at a speed of 75% maximal aerobic speed. METHODS: Thirty-six males were randomly divided into mask and nonmask groups. The kinematic and kinetic data were obtained at four time points (RN0-1 min, RN5-6 min, RN9-10 min, and RN14-15 min) during running. Two-way mixed ANOVA was applied to examine the effects between groups and times with Bonferroni post hoc comparison and independent samples t-test. RESULTS: The results showed that there was no difference between mask and nonmask group during running (p > 0.05). As running time increased, hip joint ROM, hip joint flexion/extension max, and ankle joint plantarflexion max angles increased; knee joint flexion min and ankle joint dorsiflexion max angles decreased; average peak vertical ground reaction forces (PVGRF) increased after 9 min-running (p < 0.05). CONCLUSIONS: Wearing a medical protective mask does not affect the joint angle and touchdown PVGRF of lower extremities during treadmill running while affected by running time and changed after 9 min-treadmill running. Future studies will examine the effects of wearing masks during the pandemic on muscle activation and blood biochemical values during exercise. TRIAL REGISTRATION NO: ChiCTR2000040535 (date of registration on December 1, 2020). Prospectively registered in the Chinese Clinical Trial Registry.

Analysis of Cognition, Protection, Psychological, and Job-search Intentions Among Medical and Nonmedical College Students During COVID-19 Epidemic.

Context: Since December 2019, medical practitioners discovered a novel coronavirus causing an acute respiratory-tract infection in some hospitals in Wuhan, Hubei Province. COVID-19 has spread globally, making it an epidemic worldwide at present. Understanding the mental-health responses of college students to COVID-19 can help a school staff to better guide students seeking education. Objective: The study aimed to explore the differences between nonmedical and medical college students during the COVID-19 epidemic in their cognitive interest about the disease, preventive behaviors, psychological effects, and job-search intentions, hoping to provide more targeted measures for virus-coping education for college students. Design: The research team conducted a cross-sectional study, using an anonymous online questionnaire. Setting: The study took place at Shanghai, China. Participants: Participants were 1648 college students studying different specialties in various provinces of China, 485 nonmedical students and 1163 medical students. Outcome Measures: The survey's questions covered the respondents': (1) general demographic characteristics, (2) cognitive interest and knowledge about COVID-19 and its infectiousness as well as efforts at active learning about infectious diseases and viruses, (3) awareness of precautionary behaviors against COVID-19, (4) effects on mental health, and (5) effects on job-search intentions. The research team used descriptive statistics and Chi-square tests to analyze the survey data. Results: Among nonmedical students: (1) 297 participants (61.2%) were interested in learning about COVID-19, (2) 321 participants (66.2%) took the initiative to learn about the virus, (3) 301 participants (62.1%) took the initiative to learn about infectious disease, and (4) 151 participants (31.1%) watched medical-themed movies or TV series about COVID-19. Among medical students, the corresponding proportions were 772 participants (66.4%), 855 participants (73.5%), 791 participants (68.1%), and 791 participants (68.1%), respectively. Among nonmedical students, 223 participants (46.0%) had N95 masks available, 429 participants (88.5%) had disinfectant supplies available, 271 participants (55.9%) wore goggles in public places, 75 participants (15.5%) chose public transportation, and 77 participants (15.9%) were exposed to public places in the week prior to the survey. Among medical students, the corresponding proportions were 470 participants (40.4%), 935 participants (80.4%), 575 participants (49.4%), 243 participants (20.9%), and 297 participants (25.5%), respectively. Furthermore, COVID-19 had a stronger effect on medical students' psychology and job-search ambitions. Conclusions: The news about COVID-19 piqued the interest of medical students. Nonmedical students had stronger protective behavior than medical students. The COVID-19 outbreak had a significant influence on medical students' lives, studies, and moods. In addition, COVID-19 had a greater impact on the job-search intentions of medical students.

Reply: SARS-CoV-2 vaccination in inflammatory bowel disease patients with different biological agents.

We thank Dr Mungmunpuntipantip and colleague for their interest and thoughtful comments on our publication. The authors have highlighted several important considerations for the impact of SARS-CoV-2 vaccination in inflammatory bowel disease (IBD) patients with different biological agents. We fully agree with the author's point of view, and we also point out the limitations in our meta-analysis.

Impact of SARS-CoV-2 vaccination in inflammatory bowel disease patients with different biological agents: a systematic review and meta-analysis.

BACKGROUND: There are concerns regarding the effect of biological agents on SARS-CoV-2 vaccination in patients with inflammatory bowel disease (IBD). A systematic review and meta-analysis was performed about the serological responses, breakthrough infections and clinical relapse of IBD patients treated with biological agents following SARS-CoV-2 vaccination. METHODS: Electronic databases were searched to identify relevant studies. Primary outcomes were the pooled seroconversion rates, breakthrough infection rates and clinical relapse rates after SARS-CoV-2 vaccination in IBD patients treated with biological agents. Secondary outcomes were the comparison of seroconversion rates, breakthrough infection rates and clinical relapse rates in IBD patients treated with biological agents and control cohort after SARS-CoV-2 vaccination. RESULTS: Thirty-five studies were included in this meta-analysis. A high percentage of seroconversion (96.6%, 99% and 99.2%) was achieved in IBD patients treated with anti-TNF-α therapy, vedolizumab and ustekinumab after SARS-CoV-2 vaccination, respectively. The pooled breakthrough infection rate was 2.5% and 3.9% in IBD patients treated with anti-TNF-α therapy and vedolizumab, respectively. The breakthrough infection rate in IBD patients treated with anti-TNF-α therapy was significantly lower than control cohort (RR 0.178, 95% CI 0.084-0.378). The pooled clinical relapse rate in IBD patients treated with anti-TNF-α therapy, vedolizumab and ustekinumab was 6.9%, 5.4% and 5.3%, respectively. CONCLUSION: The overall seroconversion rate after SARS-CoV-2 vaccination in IBD patients treated with biological agents is high. The overall breakthrough infection rate and clinical relapse rate in IBD patients treated with biological agents were low.

A comprehensive update on CIDO: the community-based coronavirus infectious disease ontology.

BACKGROUND: The current COVID-19 pandemic and the previous SARS/MERS outbreaks of 2003 and 2012 have resulted in a series of major global public health crises. We argue that in the interest of developing effective and safe vaccines and drugs and to better understand coronaviruses and associated disease mechenisms it is necessary to integrate the large and exponentially growing body of heterogeneous coronavirus data. Ontologies play an important role in standard-based knowledge and data representation, integration, sharing, and analysis. Accordingly, we initiated the development of the community-based Coronavirus Infectious Disease Ontology (CIDO) in early 2020. RESULTS: As an Open Biomedical Ontology (OBO) library ontology, CIDO is open source and interoperable with other existing OBO ontologies. CIDO is aligned with the Basic Formal Ontology and Viral Infectious Disease Ontology. CIDO has imported terms from over 30 OBO ontologies. For example, CIDO imports all SARS-CoV-2 protein terms from the Protein Ontology, COVID-19-related phenotype terms from the Human Phenotype Ontology, and over 100 COVID-19 terms for vaccines (both authorized and in clinical trial) from the Vaccine Ontology. CIDO systematically represents variants of SARS-CoV-2 viruses and over 300 amino acid substitutions therein, along with over 300 diagnostic kits and methods. CIDO also describes hundreds of host-coronavirus protein-protein interactions (PPIs) and the drugs that target proteins in these PPIs. CIDO has been used to model COVID-19 related phenomena in areas such as epidemiology. The scope of CIDO was evaluated by visual analysis supported by a summarization network method. CIDO has been used in various applications such as term standardization, inference, natural language processing (NLP) and clinical data integration. We have applied the amino acid variant knowledge present in CIDO to analyze differences between SARS-CoV-2 Delta and Omicron variants. CIDO's integrative host-coronavirus PPIs and drug-target knowledge has also been used to support drug repurposing for COVID-19 treatment. CONCLUSION: CIDO represents entities and relations in the domain of coronavirus diseases with a special focus on COVID-19. It supports shared knowledge representation, data and metadata standardization and integration, and has been used in a range of applications.

Feasibility of a telephone-delivered educational intervention for knowledge transfer of COVID-19-related information to older adults in Hong Kong: a pre-post-pilot study.

BACKGROUND: During the COVID-19 pandemic, educational interventions have become necessary to prevent the spread of health-related misinformation among Hong Kong older adults. The primary objective of this study was to assess the feasibility of a student-led, telephone-delivered intervention to improve COVID-19-related health knowledge among Hong Kong older adults. The secondary objective was to evaluate the impact of the intervention on the student volunteers. METHODS: Twenty-five participants aged 65 or above who were able to communicate in Cantonese and had no hearing or cognitive impairments were recruited for this longitudinal pre-post-study from a community center in Hong Kong. The pilot telephone-delivered intervention consisted of five telephone call sessions conducted by 25 student volunteers. Each participant was paired with the same volunteer throughout the intervention. The first four sessions included pre-tests that assessed the participants' understanding of three COVID-19-related themes: medication safety, healthcare voucher scheme, and COVID-19 myth-busting. Standardized explanations of the pre-test questions were offered to participants during the phone calls. In the last session, a post-test on all the themes was conducted. The intervention's feasibility was assessed based on (a) percentage changes in the participants' test scores, (b) attrition rate, and (c) the acceptability of the intervention by the participants. The impact of the intervention on the student volunteers was evaluated based on a student feedback survey. There was no control group. RESULTS: Significant improvements in the participants' test scores (out of 100%) for all themes were observed after the intervention: from 76 to 95.2% for medication safety, from 64.0 to 88.8% for the healthcare voucher scheme, and from 78.0 to 93.2% for COVID-19 myth-busting. The average improvement in test scores of the three themes was 18.4% (95% CI 12.2 to 24.6%). Most participants were satisfied with the program. The student feedback survey suggested that the intervention enhanced students' communication skills and understanding of Hong Kong older adults. CONCLUSION: This pilot study offers initial evidence of the potential and feasibility of student-led, telephone-delivered educational interventions for the transfer of COVID-19-related knowledge to older adults and their benefits for the student volunteers. Future studies should include larger samples and a control group.

Leber Hereditary Optic Neuropathy Gene Therapy: Adverse Events and Visual Acuity Results of All Patient Groups.

PURPOSE: To assess safety of gene therapy in G11778A Leber hereditary optic neuropathy (LHON). DESIGN: Phase 1 clinical trial. METHODS: Setting: single institution. PARTICIPANTS: Patients with G11778A LHON and chronic bilateral visual loss >12 months (group 1, n = 11), acute bilateral visual loss <12 months (group 2, n = 9), or unilateral visual loss (group 3, n = 8). INTERVENTION: unilateral intravitreal AAV2(Y444,500,730F)-P1ND4v2 injection with low, medium, high, and higher doses to worse eye for groups 1 and 2 and better eye for group 3. OUTCOME MEASURES: Best-corrected visual acuity (BCVA), adverse events, and vector antibody responses. Mean follow-up was 24 months (range, 12-36 months); BCVAs were compared with a published prospective natural history cohort with designated surrogate study and fellow eyes. RESULTS: Incident uveitis (8 of 28, 29%), the only vector-related adverse event, resulted in no attributable vision sequelae and was related to vector dose: 5 of 7 (71%) higher-dose eyes vs 3 of 21 (14%) low-, medium-, or high-dose eyes (P < .001). Incident uveitis requiring treatment was associated with increased serum AAV2 neutralizing antibody titers (p=0.007) but not serum AAV2 polymerase chain reaction. Improvements of ≥15-letter BCVA occurred in some treated and fellow eyes of groups 1 and 2 and some surrogate study and fellow eyes of natural history subjects. All study eyes (BCVA ≥20/40) in group 3 lost ≥15 letters within the first year despite treatment. CONCLUSIONS: G11778A LHON gene therapy has a favorable safety profile. Our results suggest that if there is an efficacy effect, it is likely small and not dose related. Demonstration of efficacy requires randomization of patients to a group not receiving vector in either eye.

Nab-paclitaxel plus S-1 versus oxaliplatin plus S-1 as first-line treatment in advanced gastric cancer: results of a multicenter, randomized, phase III trial (GAPSO study).

Background: This study aimed to investigate the superiority of nab-paclitaxel plus S-1 (AS) over oxaliplatin plus S-1 (SOX) in patients with advanced gastric cancer (AGC). Methods: In this multicenter, randomized, phase III superiority trial, eligible patients with unresectable, locally advanced gastric adenocarcinoma were recruited and randomly assigned (1:1) to receive AS (nab-paclitaxel 260 mg/m2 on day 1 or 130 mg/m2 on days 1 and 8; oral S-1 40-60 mg twice daily for 14 days) or SOX (130 mg/m2 oxaliplatin on day 1; oral S-1 40-60 mg twice daily for 14 days) every 3 weeks for up to six cycles. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival, objective response rate, and safety. Results: Owing to slow enrolment, an unplanned interim analysis was performed, resulting in the early termination of the study on 31 December 2021 (data cutoff). Between March 2019 and March 2021, 97 patients (AS, n = 48; SOX, n = 49) were treated and evaluated for efficacy and safety of AS and SOX. As of the data cutoff, the median follow-up was 23.13 months [95% confidence interval (CI), 13.39-32.87]. The median PFS was 9.03 months (95% CI, 6.50-11.56) in the AS group and 5.07 months (95% CI, 4.33-5.81) in the SOX group, demonstrating a better PFS tendency following AS treatment than SOX treatment (hazard ratio = 0.59; 95% CI, 0.37-0.94; p = 0.03). The most common grade 3 or worse adverse events were anemia, neutropenia, and leukopenia in both groups, with a higher incidence of thrombocytopenia in the SOX group. Conclusion: Although this study was terminated early, the results demonstrated a better PFS tendency in patients with AGC who were treated with AS than in those treated with SOX, with controllable toxicities. Trial registration: Clinical Trials.gov identifiers: NCT03801668. Registered January 11, 2019.

Self-reported Treatment Goals in Chinese Patients with Inflammatory Bowel Disease During the Coronavirus Disease 2019 Pandemic.

BACKGROUND: Inflammatory bowel disease is a chronic recurrent disease, and the treatment goals of inflammatory bowel disease are mainly based on doctors' perspective, but there are some differences between the doctor's perspective and the patient's perspective. The aim of this study is to understand the treatment goals and the related factors from the patients' perspective during the coronavirus disease 2019 pandemic. METHODS: A total of 212 participants were recruited to fill out the questionnaires including clinical characteristics and treatment goals. Eleven treatment goals were measured by a Short-Form 34 questionnaire. Univariate and multivariate regression analyses were used to explore the related factors about these treatment goals. RESULTS: A total of 212 inflammatory bowel disease patients were enrolled in this study. The most concerned treatment goal was the improvement of quality of life (mean score was 8.54), while mean score of ulcerative colitis patients and Crohn's disease patients was 9.10 and 8.45, respectively. We had also found some related factors such as the type of disease, the course of disease, the frequency of hematochezia, and defecation. CONCLUSION: Our survey showed that inflammatory bowel disease patients pay more attention to the improvement of quality of life and few drugs during the coronavirus disease 2019 pandemic. There are some related factors such as the type of disease, the course of dis- ease, the frequency of hematochezia, and defecation. Our results help clinicians understand the patients' treatment goals, which can contribute to better management of inflammatory bowel disease patients.

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.