Discovery and evaluation of active compounds from Xuanfei Baidu formula against COVID-19 via SARS-CoV-2 Mpro

Development of a magnetic beads-based ligand fishing method for screening SARS-CoV-2 NSP5 inhibitors from complex herbal mixtures: Rosmarinus officinalis as a case study

SARS-CoV-2 NSP5, a conserved protease essential for viral replication, represents a critical therapeutic target. Natural products provide diverse chemical scaffolds for antiviral development but remain underexploited. Traditional screening methods struggle to resolve specific inhibitors in complex herbal matrices due to selectivity and throughput limitations. To address these challenges, we developed an innovative magnetic beads-based ligand fishing strategy coupled with UPLC-Q-Exactive-Orbitrap-MS/MS for rapid discovery of SARS-CoV-2 NSP5 inhibitors from complex herbal matrices. Screening of 44 traditional Chinese medicinal extracts identified Rosmarinus officinalis as a potent inhibitor, exhibiting an IC50 of 19.90 ± 3.16 μg/mL against NSP5. Through ligand fishing and mass spectrometry analysis, 15 bioactive compounds were identified, including 8 diterpenoids (predominantly abietane-type) and 3 phenylpropanoids. Notably, rosmarinic acid demonstrated the strongest inhibition (IC50 = 5.784 ± 0.20 μM), surpassing the positive control ebselen in molecular docking studies. Structural characterization revealed that hydroxyl and carboxyl groups in diterpenoids formed critical hydrogen bonds with catalytic residues (Cys145, Ser144) of NSP5. This methodological advancement not only improved the accuracy of natural product screening but also facilitated the development of targeted antiviral strategies against SARS-CoV-2 and other emerging viral pathogens.

Intestinal-pulmonary axis: a 'Force For Good' against respiratory viral infections

Respiratory viral infections are a major global public health concern, and current antiviral therapies still have limitations. In recent years, research has revealed significant similarities between the immune systems of the gut and lungs, which interact through the complex physiological network known as the "gut-lung axis." As one of the largest immune organs, the gut, along with the lungs, forms an inter-organ immune network, with strong parallels in innate immune mechanisms, such as the activation of pattern recognition receptors (PRRs). Furthermore, the gut microbiota influences antiviral immune responses in the lungs through mechanisms such as systemic transport of gut microbiota-derived metabolites, immune cell migration, and cytokine regulation. Studies have shown that gut dysbiosis can exacerbate the severity of respiratory infections and may impact the efficacy of antiviral therapies. This review discusses the synergistic role of the gut-lung axis in antiviral immunity against respiratory viruses and explores potential strategies for modulating the gut microbiota to mitigate respiratory viral infections. Future research should focus on the immune mechanisms of the gut-lung axis to drive the development of novel clinical treatment strategies.

Comprehensive Review on Fruit of Terminalia chebula: Traditional Uses, Phytochemistry, Pharmacology, Toxicity, and Pharmacokinetics

Terminalia chebula Retz., known for its dried fruit, namely Chebulae Fructus, is a medicinal plant with a long-standing global reputation, which was initially recognized for its therapeutic properties during the Jin Dynasty. This review consolidates current knowledge on the traditional uses, phytochemistry, pharmacological properties, toxicity, and pharmacokinetics of Chebulae Fructus, highlighting its clinical significance and the promising therapeutic potential of its compounds. To date, studies have identified approximately 149 compounds within the plant, including tannins, phenolic acids, lignans, triterpenes, flavonoids, and volatiles. These compounds confer a broad spectrum of biological activities in vitro and in vivo, such as antioxidant, anti-inflammatory, antiviral, anticancer, antibacterial, hepatoprotective, nephroprotective, neuroprotective, and anti-diabetic, some of which are already integrated into clinical practice. However, despite substantial advancements, considerable gaps remain in understanding the complete mechanisms of action, pharmacokinetics, and safety profiles of its extracts and compounds. This paper advocates for enhanced focus on these areas to fully elucidate the therapeutic capacities and facilitate the clinical application of Chebulae Fructus. This comprehensive analysis not only reinforces the ethnopharmacological significance of Chebulae Fructus but also lays a foundation for future pharmacological explorations.

A SAR and QSAR study on 3CLpro inhibitors of SARS-CoV-2 using machine learning methods

The 3C-like Proteinase (3CLpro) of novel coronaviruses is intricately linked to viral replication, making it a crucial target for antiviral agents. In this study, we employed two fingerprint descriptors (ECFP_4 and MACCS) to comprehensively characterize 889 compounds in our dataset. We constructed 24 classification models using machine learning algorithms, including Support Vector Machine (SVM), Random Forest (RF), extreme Gradient Boosting (XGBoost), and Deep Neural Networks (DNN). Among these models, the DNN- and ECFP_4-based Model 1D_2 achieved the most promising results, with a remarkable Matthews correlation coefficient (MCC) value of 0.796 in the 5-fold cross-validation and 0.722 on the test set. The application domains of the models were analysed using dSTD-PRO calculations. The collected 889 compounds were clustered by K-means algorithm, and the relationships between structural fragments and inhibitory activities of the highly active compounds were analysed for the 10 obtained subsets. In addition, based on 464 3CLpro inhibitors, 27 QSAR models were constructed using three machine learning algorithms with a minimum root mean square error (RMSE) of 0.509 on the test set. The applicability domains of the models and the structure-activity relationships responded from the descriptors were also analysed.

Risk prediction for severe COVID-19 progressing to critical illness and death in the ICU and efficacy analysis of using traditional Chinese medicine

To reveal the key factors influencing the progression of severe COVID-19 to critical illness and death in the intensive care unit (ICU) and to accurately predict the risk, as well as to validate the efficacy of treatment using traditional Chinese medicine (TCM), thus providing valuable recommendations for the clinical management of patients. A total of 189 patients with COVID-19 in 25 ICUs in Chongqing, China, were enrolled, and 16 eventually died. Statistical models shown that factors influencing the progression of COVID-19 to critical illness include the severity of illness at diagnosis, the mode of respiratory support, and the use of TCM. Risk factors for death include a history of metabolic disease, the use of antiviral drugs and TCM, and invasive endotracheal intubation. The area under curve of the noncollinearity model predicted the risk of progression to critical illness and the risk of death reached 0.847 and 0.876, respectively. The use of TCM is an independent protective factor for the prevention of the progression of severe COVID-19, while uncorrectable hypoxemia and invasive respiratory support are independent risk factors, and antiviral drugs can help reduce mortality. The multifactorial prediction model can assess the risk of critical illness and death in ICU COVID-19 patients, and inform clinicians in choosing the treatment options and medications.

Stand Up to Stand Out: Natural Dietary Polyphenols Curcumin, Resveratrol, and Gossypol as Potential Therapeutic Candidates against Severe Acute Respiratory Syndrome Coronavirus 2 Infection

The COVID-19 pandemic has stimulated collaborative drug discovery efforts in academia and the industry with the aim of developing therapies and vaccines that target SARS-CoV-2. Several novel therapies have been approved and deployed in the last three years. However, their clinical application has revealed limitations due to the rapid emergence of viral variants. Therefore, the development of next-generation SARS-CoV-2 therapeutic agents with a high potency and safety profile remains a high priority for global health. Increasing awareness of the "back to nature" approach for improving human health has prompted renewed interest in natural products, especially dietary polyphenols, as an additional therapeutic strategy to treat SARS-CoV-2 patients, owing to its good safety profile, exceptional nutritional value, health-promoting benefits (including potential antiviral properties), affordability, and availability. Herein, we describe the biological properties and pleiotropic molecular mechanisms of dietary polyphenols curcumin, resveratrol, and gossypol as inhibitors against SARS-CoV-2 and its variants as observed in in vitro and in vivo studies. Based on the advantages and disadvantages of dietary polyphenols and to obtain maximal benefits, several strategies such as nanotechnology (e.g., curcumin-incorporated nanofibrous membranes with antibacterial-antiviral ability), lead optimization (e.g., a methylated analog of curcumin), combination therapies (e.g., a specific combination of plant extracts and micronutrients), and broad-spectrum activities (e.g., gossypol broadly inhibits coronaviruses) have also been emphasized as positive factors in the facilitation of anti-SARS-CoV-2 drug development to support effective long-term pandemic management and control.