Natural Products, Alone or in Combination with FDA-Approved Drugs, to Treat COVID-19 and Lung Cancer

Daurisoline inhibits glycolysis of lung cancer by targeting the AKT-HK2 axis

Lung cancer, one of the most prevalent tumors, remains a clinical challenge with a poor five-year survival rate. Daurisoline, a bis-benzylisoquinoline alkaloid derived from the traditional Chinese herb Menispermum dauricum, is known to suppress tumor growth effectively. However, its precise mechanism of action remains unclear. In this study, we demonstrate that Daurisoline targets glycolysis and reduces the protein level of HK2, thereby inhibiting lung cancer progression. Mechanistic investigations reveal that Daurisoline directly binds to AKT and antagonizes the AKT-GSK3β-c-Myc-HK2 signaling axis. Furthermore, in an animal model, we validate the in vivo anti-tumor effect of Daurisoline without any observable side effects. Overall, our findings suggest that Daurisoline holds potential as an anti-tumor agent through its targeting of glycolysis.

Synthesis, antiproliferative activity, and biological profiling of C-19 trityl and silyl ether andrographolide analogs in colon cancer and breast cancer cells

Andrographolide, a labdane diterpenoid isolated from Andrographis paniculata, putatively functions through covalent inhibition of NF-κB, a transcription factor that modulates tumor survival and metastasis. Previous studies have found that functionalization of the C-19 hydroxyl alters the primary mode of action from inhibition of NF-κB to the modulation of the Wnt1/β-catenin signaling pathway. Here, we synthesized a series of twelve C-19 trityl and silyl ether analogs, including three novel substituted trityl analogs and four novel substituted silyl analogs of andrographolide. MTT assays revealed cell line selectivity between colorectal and breast cancer cells, which is consistent with known mechanisms of β-catenin-driven cell proliferation in colorectal cancer cell lines. Most compounds exhibited cell line specific antiproliferative activity in HCT-116 and HT-29 colorectal cancer cell lines. Specifically, within 24 h, C-19 analogs of andrographolide exhibit far more limited antiproliferative activity in MCF-7 breast cancer cells compared to HCT-116, HT-29, and MDA-MB-231 cells. Through in vitro TNF-α-dependent NF-κB reporter and Wnt1-dependent luciferase reporter assays, we observed that several analogs generally exhibit greater inhibitory activity compared to andrographolide. Fluorescence imaging demonstrated that cells treated with andrographolide and its C-19 analogs retained similar distributions of active β-catenin, but notable differences in antiproliferative potency upon co-delivery with GSK-3β inhibitor CHIR99021 indicate that several lead compounds exhibit attenuated biological activity selectively in HT-29 cells. Collectively, this work indicates that modest structural modifications at C-19 of andrographolide can have profound implications for its biological activity in mechanisms connected to its anticancer activity.

A computer-aided, carrier-free drug delivery system with enhanced cytotoxicity and biocompatibility: A universal model for multifunctional lung cancer therapy

Erlotinib (ERL) is a first-line targeted therapy for patients with epidermal growth factor receptor (EGFR)-mutant advanced non-small cell lung cancer (NSCLC). However, its effectiveness is hindered by acquired resistance and poor bioavailability. Carrier-free nanodrugs are a research hotspot due to their efficient targeting, high drug loading capacity, and the absence of any excipients. Herein, we report an advanced self-delivery system for multimodal NSCLC therapy using a computer-aided strategy. First, we developed a novel heterodimer, ERL-SS-QM (ERL conjugated with QM-OH-a hydrophobic aggregation-induced emission fluorophore-via a disulfide bond [SS]), which serves as both cargo and carrier material. Self-assembly is driven by multiple noncovalent interactions, including π-π stacking and sulfur bonds. Subsequently, an ERL-SS-QM-based "triadic" drug delivery nanoplatform comprising 21 variants was developed. A case study on ursolic acid (UA)-loaded ERL-SS-QM nanoparticles (named UA@ERL-SS-QM NPs) revealed narrow size distribution, small particle size, and well stabilized (zeta potential = -28.9 mV). The UA@ERL-SS-QM NPs demonstrated concentration-dependent toxicity against targeted A549 cells (IC50 = 4.36 μM), outperforming free monomeric drugs ERL (IC50 = 12.94 μM) and UA (IC50 = 12.21 μM), indicating good efficiency. Conversely, these NPs exhibited minimal cytotoxicity in non-targeted BEAS-2B cells, suggesting favorable biocompatibility. Upon endocytosis and interaction with overexpressed GSH in A549 cells, the disulfide-bond linker is cleaved to release three components: ERL, UA (which downregulates β-catenin/TCF4/CT45A2 signaling pathways, inducing apoptosis in ERL-resistant L858R/T790M mutant cells-a key factor in acquired resistance to ERL treatment), and QM-OH. Hence, this work provides a universal model for multifunctional NSCLC therapy that effectively addresses ERL resistance while enhancing cytotoxicity and biocompatibility.

The Antiviral Activity of Polyphenols

Polyphenols are secondary metabolites produced by a large variety of plants. These compounds that comprise the class of phenolic acids, stilbenes, lignans, coumarins, flavonoids, and tannins have a wide range of employment, from food production to medical usages. Among the beneficial applications of polyphenols, their antiviral activity is gaining importance due to the increased prevalence of drug-resistant viruses such as herpes and hepatitis B viruses. In the present review, we provide an overview of the most promising or commonly used antiviral polyphenols and their mechanisms of action focusing on their effects on enveloped viruses of clinical importance (double-stranded linear or partially double-stranded circular DNA viruses, negative sense single-stranded RNA viruses with nonsegmented or segmented genomes, and positive sense single-stranded RNA viruses). The present work emphasizes the relevance of polyphenols, in particular epigallocatechin-3-gallate and resveratrol, as alternative or supportive antivirals. Polyphenols could interfere with virtually all steps of viral infection, from the adsorption to the release of viral particles. The activity of polyphenols against viruses is especially relevant given the risk of widespread outbreaks associated with viruses, remarked by the recent COVID-19 pandemic.

Synergistic attenuation of complete freund's adjuvant-induced inflammation in mice using shinbaro-pelubiprofen: a novel therapeutic complex

BACKGROUND

Inflammation is a critical protective response in the body, essential for combating infections and healing injuries. However, chronic inflammation can be harmful and significantly contribute to the development and progression of chronic diseases, with macrophage-mediated responses being central to these processes. This study presents "SBR-Pel," a new therapeutic blend of Shinbaro tab (SBR), a traditional herbal formula, and pelubiprofen (Pel), a non-steroidal anti-inflammatory drug, and investigated their combined anti-inflammatory effects to create a treatment that both improves efficacy and reduces side effects.

METHODS

To this end, we performed both in vitro and in vivo analyses, utilizing a mouse model of inflammation. Viability and cytotoxicity assays, immunohistochemistry, enzyme-linked immunosorbent assays, real-time polymerase chain reaction assays, nociception assays, writhing tests, and blood biochemical analyses were performed.

RESULTS

In vitro, SBR-Pel synergistically reduced the production of nitric oxide and reactive oxygen species and the expression of pro-inflammatory cytokines. SBR-Pel also significantly attenuated paw edema in vivo in a Complete Freund's adjuvant-induced inflammation model in adult mice. Furthermore, immunohistochemical analyses showed that treatment with SBR-Pel reduced both the infiltration of CD68+ macrophages and the expression of pro-inflammatory cytokines in inflamed tissues. Additionally, compared with individual treatment alone, SBR-Pel enhanced the expression of anti-inflammatory cytokines CD206, TGF-β, and IL-10, indicating a synergistic effect. Our research demonstrates that SBR-Pel effectively diminishes inflammatory pain by reducing macrophage infiltration and pro-inflammatory cytokine secretion. Additionally, while 1.5 mg/kg of Pel alone increases levels of liver and kidney toxicity markers, such as aspartate aminotransferase, alanine aminotransferase, and creatinine, combining it with SBR at a reduced dosage of 0.5 mg/kg maintains these markers at normal levels.

CONCLUSIONS

This combined effect highlights SBR-Pel's potential as an effective treatment for inflammatory diseases driven by heightened macrophage activity, while also minimizing side effects by reducing the Pel dosage.

Cepharanthine sensitizes gastric cancer cells to chemotherapy by targeting TRIB3-FOXO3-FOXM1 axis to inhibit autophagy

BACKGROUND

Gastric cancer is among the common solid tumors. Chemotherapy resistance is the most common issue in gastric cancer treatment. Inhibiting intracellular autophagy may be a feasible method for overcoming chemotherapy resistance. Cepharanthine (CEP), a natural small molecule extracted from the stephania cephalantha Hayata plant, has been demonstrated to significantly inhibit cancer growth and can regulate autophagy. Although CEP can significantly inhibit cancer growth, it remains unclear whether CEP can regulate autophagy in gastric cancer. This study aimed to investigate whether CEP can enhance the sensitivity of gastric cancer to chemotherapy and elucidate its molecular mechanism.

METHODS

Three gastric cancer cell lines (AGS, SGC7901, and MFC) and one normal gastric mucosal epithelial cell line (GES-1) were used for in vitro experiments. The characterization of autophagy in gastric cancer cells included the detection of autophagy markers and autophagy flux through immunofluorescence staining and Western blotting, as well as the assessment of lysosomal function using fluorescence staining (LysoTracker Red DND-99, Acridine Orange staining) and Western blotting. The cytotoxicity of CEP, autophagy inhibitors (chloroquine [CQ] and 3-methyladenine [3MA]), and chemotherapy drugs (doxorubicin [DOX] and cisplatin [CIS]) was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, cell colony formation, and fluorescence staining techniques (H2DCFDA, Dihydroethidium, and JC-1 staining). The interaction between CEP and autophagy inhibitors was tested in a 615 mice model, and changes in the gut microbiota were determined through accurate 16S absolute quantification sequencing. The signaling pathway and autophagy regulatory target TRIB3-FOXO3-FOXM1 were confirmed through molecular docking, RNA sequencing, bioinformatic analysis, transfection techniques, and Western blotting.

RESULTS

CEP blocked autophagic flux in gastric cancer cells without affecting lysosomal function. As a novel autophagy inhibitor, CEP could combine with conventional autophagy inhibitors (CQ and 3MA) to block intracellular autophagy, thereby inhibiting gastric cancer growth. During this process, changes in the gut microbiota were observed, including low-level changes in Odoribacterium, Erysipelatoclostridium, and ParaPrevotella and high-level changes in Ileibacterium, Enterorhabdus, and Bifidobacterium. Additionally, CEP synergistically inhibited the growth of gastric cancer when combined with chemotherapy drugs. Mechanistically, the TRIB3-FOXO3-FOXM1 signaling axis was found to be involved in the inhibition of gastric cancer by CEP combined with autophagy inhibitors and chemotherapy drugs, thereby mediating cell apoptosis.

CONCLUSION

This study links the TRIB3-FOXO3-FOXM1 axis with chemotherapy efficacy. Our findings demonstrated that CEP inhibits autophagy by modulating the FOXO3-FOXM1 axis. When combined with chemotherapy drugs (DOX and CIS), CEP, as an autophagy inhibitor, can limit TRIB3 protein expression, thereby regulating the FOXO3-FOXM1 axis and enhancing its ability to prevent gastric cancer growth. These findings may contribute to improving the prognosis of patients with gastric cancer. Furthermore, these results enrich the fundamental understanding of how autophagy inhibition can enhance clinical cancer treatment efficacy and provide insights into the potential mechanisms by which CEP functions as an anti-tumor drug, thereby exploring its value for clinical application.

Oral Bioavailability, Tissue Distribution, Metabolism, and Excretion of Panduratin A from Boesenbergia rotunda Extract in Healthy Rats

Background

Our previous studies in vitro and in vivo have shown anti-severe acute respiratory syndrome coronavirus 2 activity of fingerroot extract (Boesenbergia rotunda) and its phytochemical panduratin A.

Aim of Study

Therefore, the objective of this study was to determine the pharmacokinetic profiles of panduratin A, as a pure compound and in fingerroot extract, in rats.

Materials and Methods

Male rats were randomly divided into four groups. Rats underwent intravenous administration of 4.5 mg/kg panduratin A, a single oral administration of 45 mg/kg panduratin A, or a multiple oral administration of 45 mg/kg panduratin A-consisted fingerroot extract for 7 consecutive days. The concentrations of panduratin A in plasma, tissues, and excreta were measured by using LCMS with a validated method.

Results

The rats showed no change in health status after receiving all test preparations. The absolute oral bioavailability of panduratin A administered as pure panduratin A and fingerroot extract were approximately 9% and 6%, respectively. The peak concentrations for the single oral doses of 45 mg/kg panduratin A and fingerroot extract, were 4833 ± 659 and 3269 ± 819 µg/L, respectively. Panduratin A was mostly distributed in gastrointestinal organs, with the highest tissue-to-plasma ratio in the stomach. Approximately 20-30% of unchanged panduratin A from the administered dose was detected in feces while a negligible amount was found in urine. The major metabolites of administered panduratin A were identified in feces as oxidation and dioxidation products.

Conclusion

Panduratin A from fingerroot extract showed low oral bioavailability, good tissue distribution, and partially biotransformed before excretion via feces. These findings will assist in developing fingerroot extract as a phytopharmaceutical product for COVID-19 treatment.

Sedative and hypnotic effects of the saponins from a traditional edible plant Liriope spicata Lour. in PCPA-induced insomnia mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liriope spicata Lour., a species listed in the catalogue of 'Medicinal and Edible Homologous Species', is traditionally used for the treatment of fatigue, restlessness, insomnia and constipation.

AIM OF THE STUDY

This study is aimed to evaluate the sedative and hypnotic effect of the saponins from a natural plant L. spicata Lour. in vivo.

MATERIALS AND METHODS

The total saponin (LSTS) and purified saponin (LSPS) were extracted from L. spicata, followed by a thorough analysis of their major components using the HPLC-MS. Subsequently, the therapeutic efficacy of LSTS and LSPS was evaluated by the improvement of anxiety and depression behaviors of the PCPA-induced mice.

RESULTS

LSTS and LSPS exhibited similar saponin compositions but differ in their composition ratios, with liriopesides-type saponins accounting for a larger proportion in LSTS. Studies demonstrated that both LSTS and LSPS can extend sleep duration and immobility time, while reducing sleep latency in PCPA-induced mice. However, there was no significant difference in weight change among the various mice groups. Elisa results indicated that the LSTS and LSPS could decrease levels of NE, DA, IL-6, and elevate the levels of 5-HT, NO, PGD2 and TNF-α in mice plasma. LSTS enhanced the expression of neurotransmitter receptors, while LSPS exhibited a more pronounced effect in regulating the expression of inflammatory factors. In conclusion, the saponins derived from L. spicata might hold promise as ingredients for developing health foods with sedative and hypnotic effects, potentially related to the modulation of serotonergic and GABAAergic neuron expression, as well as immunomodulatory process.

Synthesis of Rhodamine-Conjugated Lupane Type Triterpenes of Enhanced Cytotoxicity

Various conjugates with rhodamines were prepared by starting with betulinic acid (BA) and platanic acid (PA). The molecules homopiperazine and piperazine, which were identified in earlier research, served as linkers between the rhodamine and the triterpene. The pentacyclic triterpene's ring A was modified with two acetyloxy groups in order to possibly boost its cytotoxic activity. The SRB assays' cytotoxicity data showed that conjugates 13-22, derived from betulinic acid, had a significantly higher cytotoxicity. Of these hybrids, derivatives 19 (containing rhodamine B) and 22 (containing rhodamine 101) showed the best values with EC50 = 0.016 and 0.019 μM for A2780 ovarian carcinoma cells. Additionally, based on the ratio of EC50 values, these two compounds demonstrated the strongest selectivity between malignant A2780 cells and non-malignant NIH 3T3 fibroblasts. A375 melanoma cells were used in cell cycle investigations, which showed that the cells were halted in the G1/G0 phase. Annexin V/FITC/PI staining demonstrated that the tumor cells were affected by both necrosis and apoptosis.

Innovative Delivery Systems for Curcumin: Exploring Nanosized and Conventional Formulations

Curcumin, a polyphenol with a rich history spanning two centuries, has emerged as a promising therapeutic agent targeting multiple signaling pathways and exhibiting cellular-level activities that contribute to its diverse health benefits. Extensive preclinical and clinical studies have demonstrated its ability to enhance the therapeutic potential of various bioactive compounds. While its reported therapeutic advantages are manifold, predominantly attributed to its antioxidant and anti-inflammatory properties, its efficacy is hindered by poor bioavailability stemming from inadequate absorption, rapid metabolism, and elimination. To address this challenge, nanodelivery systems have emerged as a promising approach, offering enhanced solubility, biocompatibility, and therapeutic effects for curcumin. We have analyzed the knowledge on curcumin nanoencapsulation and its synergistic effects with other compounds, extracted from electronic databases. We discuss the pharmacokinetic profile of curcumin, current advancements in nanoencapsulation techniques, and the combined effects of curcumin with other agents across various disorders. By unifying existing knowledge, this analysis intends to provide insights into the potential of nanoencapsulation technologies to overcome constraints associated with curcumin treatments, emphasizing the importance of combinatorial approaches in improving therapeutic efficacy. Finally, this compilation of study data aims to inform and inspire future research into encapsulating drugs with poor pharmacokinetic characteristics and investigating innovative drug combinations to improve bioavailability and therapeutic outcomes.

Natural-product-based, carrier-free, noncovalent nanoparticles for tumor chemo-photodynamic combination therapy

Cancer, with its diversity, heterogeneity, and complexity, is a significant contributor to global morbidity, disability, and mortality, highlighting the necessity for transformative treatment approaches. Photodynamic therapy (PDT) has aroused continuous interest as a viable alternative to conventional cancer treatments that encounter drug resistance. Nanotechnology has brought new advances in medicine and has shown great potential in drug delivery and cancer treatment. For precise and efficient therapeutic utilization of such a tumor therapeutic approach with high spatiotemporal selectivity and minimal invasiveness, the carrier-free noncovalent nanoparticles (NPs) based on chemo-photodynamic combination therapy is essential. Utilizing natural products as the foundation for nanodrug development offers unparalleled advantages, including exceptional pharmacological activity, easy functionalization/modification, and well biocompatibility. The natural-product-based, carrier-free, noncovalent NPs revealed excellent synergistic anticancer activity in comparison with free photosensitizers and free bioactive natural products, representing an alternative and favorable combination therapeutic avenue to improve therapeutic efficacy. Herein, a comprehensive summary of current strategies and representative application examples of carrier-free noncovalent NPs in the past decade based on natural products (such as paclitaxel, 10-hydroxycamptothecin, doxorubicin, etoposide, combretastatin A4, epigallocatechin gallate, and curcumin) for tumor chemo-photodynamic combination therapy. We highlight the insightful design and synthesis of the smart carrier-free NPs that aim to enhance PDT efficacy. Meanwhile, we discuss the future challenges and potential opportunities associated with these NPs to provide new enlightenment, spur innovative ideas, and facilitate PDT-mediated clinical transformation.

Biobran/MGN-3, an Arabinoxylan Rice Bran, Exerts Anti-COVID-19 Effects and Boosts Immunity in Human Subjects

Corona Virus Disease 19 (COVID-19) has been a major pandemic impacting a huge population worldwide, and it continues to present serious health threats, necessitating the development of novel protective nutraceuticals. Biobran/MGN-3, an arabinoxylan rice bran, is a potent immunomodulator for both humans and animals that has recently been demonstrated to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. We here investigate Biobran/MGN-3's potential to enhance an antiviral immune response in humans. Peripheral blood mononuclear cells (PBMCs) derived from eight subjects taking Biobran/MGN-3 (age 55-65 years) and eight age-matched control subjects were stimulated with irradiated SARS-CoV-2 virus and then subjected to immuno-phenotyping and multiplex cytokine/chemokine assays. Results showed that PBMCs from subjects supplemented with Biobran/MGN-3 had significantly increased activation of plasmacytoid dendritic cells (pDCs) coupled with increased IFN-α secretion. We also observed higher baseline expression of HLA-DR (human leukocyte antigen-DR isotype) on dendritic cells (DCs) and increased secretion of chemokines and cytokines, as well as a substantial increase in cytotoxic T cell generation for subjects taking Biobran/MGN-3. Our results suggest that Biobran/MGN-3 primes immunity and therefore may be used for boosting immune responses against SARS-CoV-2 infections and other diseases, particularly in high-risk populations such as the elderly.

Cepharanthine analogs mining and genomes of Stephania accelerate anti-coronavirus drug discovery

Cepharanthine is a secondary metabolite isolated from Stephania. It has been reported that it has anti-conronaviruses activities including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Here, we assemble three Stephania genomes (S. japonica, S. yunnanensis, and S. cepharantha), propose the cepharanthine biosynthetic pathway, and assess the antiviral potential of compounds involved in the pathway. Among the three genomes, S. japonica has a near telomere-to-telomere assembly with one remaining gap, and S. cepharantha and S. yunnanensis have chromosome-level assemblies. Following by biosynthetic gene mining and metabolomics analysis, we identify seven cepharanthine analogs that have broad-spectrum anti-coronavirus activities, including SARS-CoV-2, Guangxi pangolin-CoV (GX_P2V), swine acute diarrhoea syndrome coronavirus (SADS-CoV), and porcine epidemic diarrhea virus (PEDV). We also show that two other genera, Nelumbo and Thalictrum, can produce cepharanthine analogs, and thus have the potential for antiviral compound discovery. Results generated from this study could accelerate broad-spectrum anti-coronavirus drug discovery.

Genistein: a promising modulator of apoptosis and survival signaling in cancer

Genistein, a commonly occurring isoflavone, has recently gained popularity owing to its ever-expanding spectrum of pharmacological benefits. In addition to health benefits such as improved bone health and reduced postmenopausal complications owing to its phytoestrogen properties, it has been widely evaluated for its anti-cancer potential. Several studies have established the potential for its usage in the management of breast, lung, and prostate cancers, and its usage has significantly evolved from early applications in traditional systems of medicine. This review offers an insight into its current status of usage, the chemistry, and pharmacokinetics of the molecule, an exploration of its apoptotic mechanisms in cancer management, and opportunities for synergism to improve therapeutic outcomes. In addition to this, the authors have presented an overview of recent clinical trials, to offer an understanding of contemporary studies and explore prospects for a greater number of focused trials, moving forward. Advancements in the application of nanotechnology as a strategy to improve safety and efficacy have also been highlighted, with a brief discussion of results from safety and toxicology studies.

Polyphenolic natural products as photosensitizers for antimicrobial photodynamic therapy: recent advances and future prospects

Antimicrobial photodynamic therapy (aPDT) has become a potent contender in the fight against microbial infections, especially in the context of the rising antibiotic resistance crisis. Recently, there has been significant interest in polyphenolic natural products as potential photosensitizers (PSs) in aPDT, given their unique chemical structures and inherent antimicrobial properties. Polyphenolic natural products, abundant and readily obtainable from natural sources, are generally regarded as safe and highly compatible with the human body. This comprehensive review focuses on the latest developments and future implications of using natural polyphenols as PSs in aPDT. Paramount polyphenolic compounds, including curcumin, hypericin, quercetin, hypocrellin, celastrol, riboflavin, resveratrol, gallic acid, and aloe emodin, are elaborated upon with respect to their structural characteristics, absorption properties, and antimicrobial effects. Furthermore, the aPDT mechanism, specifically its targeted action on microbial cells and biofilms, is also discussed. Polyphenolic natural products demonstrate immense potential as PSs in aPDT, representing a promising alternate approach to counteract antibiotic-resistant bacteria and biofilm-related infections.

Phytocompound screening, antioxidant activity and molecular docking studies of pomegranate seed: a preventive approach for SARS-CoV-2 pathogenesis

A global hazard to public health has been generated by the coronavirus infection 2019 (COVID-19), which is spreading quickly. Pomegranate is a strong source of antioxidants and has demonstrated a number of pharmacological characteristics. This work was aimed to analyze the phytochemicals present in ethanolic pomegranate seed extract (PSE) and their in vitro antioxidant potential and further in-silico evaluation for antiviral potential against crystal structure of two nucleocapsid proteins i.e., N-terminal RNA binding domain (NRBD) and C-terminal Domain (CTD) of SARS-CoV-2. The bioactive components from ethanolic extract of PSE were assessed by gas chromatography-mass spectroscopy (GC-MS). Free radical scavenging activity of PSE was determined using DPPH dye. Molecular docking was executed through the Glide module of Maestro software. Lipinski's 5 rule was applied for drug-likeness characteristics using cheminformatics Molinspiration software while OSIRIS Data Warrior V5.5.0 was used to predict possible toxicological characteristics of components. Thirty-two phytocomponents was detected in PSE by GC-MS technique. Free radical scavenging assay revealed the high antioxidant capacity of PSE. Docking analysis showed that twenty phytocomponents from PSE exhibited good binding affinity (Docking score ≥ - 1.0 kcal/mol) towards NRBD and CTD nucleocapsid protein. This result increases the possibility that the top 20 hits could prevent the spread of SARS-CoV-2 by concentrating on both nucleocapsid proteins. Moreover, molecular dynamics (MD) simulation using GROMACS was used to check their binding efficacy and internal dynamics of top complexes with the lowest docking scores. The metrics root mean square deviation (RMSD), root mean square fluctuation (RMSF), intermolecular hydrogen bonding (H-bonds) and radius of gyration (Rg) revealed that the lead phytochemicals form an energetically stable complex with the target protein. Majority of the phytoconstituents exhibited drug-likeness with non-tumorigenic properties. Thus, the PSE phytoconstituents could be useful source of drug or nutraceutical development in SARS-CoV-2 pathogenesis.

An Overview on Anti-COVID-19 Drug Achievements and Challenges Ahead

The appearance of several coronavirus pandemics/epidemics during the last two decades (SARS-CoV-1 in 2002, MERS-CoV in 2012, and SARS-CoV-2 in 2019) indicates that humanity will face increasing challenges from coronaviruses in the future. The emergence of new strains with similar transmission characteristics as SARS-CoV-2 and mortality rates similar to SARS-CoV-1 (∼10% mortality) or MERS-CoV (∼35% mortality) in the future is a terrifying possibility. Therefore, getting enough preparations to face such risks is an inevitable necessity. The present study aims to review the drug achievements and challenges in the fight against SARS-CoV-2 with a combined perspective derived from pharmacology, pharmacotherapy, and medicinal chemistry insights. Appreciating all the efforts made during the past few years, there is strong evidence that the desired results have not yet been achieved and research in this area should still be pursued seriously. By expressing some pessimistic possibilities and concluding that the drug discovery and pharmacotherapy of COVID-19 have not been successful so far, this short essay tries to draw the attention of responsible authorities to be more prepared against future coronavirus epidemics/pandemics.

Extracts of Thesium chinense inhibit SARS-CoV-2 and inflammation in vitro

CONTEXT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading rapidly. Relevant research based on the antiviral effects of Thesium chinense Turcz (Santalaceae) was not found.

OBJECTIVE

To investigate the antiviral and anti-inflammatory effects of extracts of T. chinense.

MATERIALS AND METHODS

To investigate the anti-entry and replication effect of the ethanol extract of T. chinense (drug concentration 80, 160, 320, 640, 960 μg/mL) against the SARS-CoV-2. Remdesivir (20.74 μM) was used as positive control, and Vero cells were used as host cells to detect the expression level of nucleocapsid protein (NP) in the virus by real-time quantitative polymerase chain reaction (RT-PCR) and Western blotting. RAW264.7 cells were used as an anti-inflammatory experimental model under lipopolysaccharide (LPS) induction, and the expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The ethanol extract of T. chinense significantly inhibited the replication (half maximal effective concentration, EC50: 259.3 μg/mL) and entry (EC50: 359.1 μg/mL) of SARS-CoV-2 into Vero cells, and significantly reduced the levels of IL-6 and TNF-α produced by LPS-stimulated RAW264.7 cells. Petroleum ether (EC50: 163.6 μg/mL), ethyl acetate (EC50: 22.92 μg/mL) and n-butanol (EC50: 56.8 μg/mL) extracts showed weak inhibition of SARS-CoV-2 replication in Vero cells, and reduced the levels of IL-6 and TNF-α produced by LPS-stimulated RAW264.7 cells.

CONCLUSION

T. chinense can be a potential candidate to fight SARS-CoV-2, and is becoming a traditional Chinese medicine candidate for treating COVID-19.

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.

Bench-to-bedside: Innovation of small molecule anti-SARS-CoV-2 drugs in China

The ongoing COVID-19 pandemic has resulted in millions of deaths globally, highlighting the need to develop potent prophylactic and therapeutic strategies against SARS-CoV-2. Small molecule inhibitors (remdesivir, Paxlovid, and molnupiravir) are essential complements to vaccines and play important roles in clinical treatment of SARS-CoV-2. Many advances have been made in development of anti-SARS-CoV-2 inhibitors in China, but progress in discovery and characterization of pharmacological activity, antiviral mechanisms, and clinical efficacy are limited. We review development of small molecule anti-SARS-CoV-2 drugs (azvudine [approved by the NMPA of China on July 25, 2022], VV116 [approved by the NMPA of China on January 29, 2023], FB2001, WPV01, pentarlandir, and cepharanthine) in China and summarize their pharmacological activity, potential mechanisms of action, clinical trials and use, and important milestones in their discovery. The role of structural biology in drug development is also reviewed. Future studies should focus on development of diverse second-generation inhibitors with excellent oral bioavailability, superior plasma half-life, increased antiviral activity against SARS-CoV-2 and its variants, high target specificity, minimal side effects, reduced drug-drug interactions, and improved lung histopathology.

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.

Real-World Effectiveness of Nirmatrelvir/Ritonavir and Dexamethasone Among Hospitalized Patients with COVID-19: A Prospective Cohort Study

Purpose

Anti-viral and anti-inflammatory therapies were effective in altering virus repletion and immune dysregulation in Coronavirus Disease 2019 (COVID-19) patients. This study aimed to explore the effect of combination therapy on disease progression in a real-world setting.

Patients and Methods

A total of 836 patients confirmed with SARS-CoV-2 infection participated in the study from 15 November to 25 December 2022 at Beijing Youan Hospital, Capital Medical University. A prospective cohort study was implemented to investigate the prognostic effect of the combination therapy on virus shedding and clinical recovery.

Results

About 78% of patients used nirmatrelvir/ritonavir (N/R, Paxlovid®, Pfizer) negatively, 16% of patients were prescribed nirmatrelvir/ritonavir beyond five days of symptom onset, 4% of patients received N/R monotherapy within five days of symptom onset and 2% of patients received N/R combined with dexamethasone. Compared with untreated patients, N/R monotherapy reduced the median time to 10.0 days from 12.0 days according to the negative conversion of nucleic acid amplification test (NAAT), and combination therapy reduced the time to 7.0 days, and increased to a 1.99 (95% CI 0.92, 4.32) and 14.23-fold (95% CI 4.50, 44.95) probability of negative NAAT, respectively. N/R monotherapy reduced the clinical recovery time to 10.0 days from 13.0 days. Single-use and combined-use non-significantly increased the recovery probability by 61% and 69%, respectively. In mild and moderate patients, the HRs for clinical recovery increased to 1.69 (95% CI 0.73, 3.94) and 2.18 (95% CI 0.29, 16.62), respectively.

Conclusion

Combination therapy of N/R and dexamethasone increased negative conversion of NAAT and was associated with a non-significant improvement in clinical recovery. Further studies are warranted to confirm this efficacy.

The Therapeutic Potential of Natural Dietary Flavonoids against SARS-CoV-2 Infection

The exploration of non-toxic and cost-effective dietary components, such as epigallocatechin 3-gallate and myricetin, for health improvement and disease treatment has recently attracted substantial research attention. The recent COVID-19 pandemic has provided a unique opportunity for the investigation and identification of dietary components capable of treating viral infections, as well as gathering the evidence needed to address the major challenges presented by public health emergencies. Dietary components hold great potential as a starting point for further drug development for the treatment and prevention of SARS-CoV-2 infection owing to their good safety, broad-spectrum antiviral activities, and multi-organ protective capacity. Here, we review current knowledge of the characteristics-chemical composition, bioactive properties, and putative mechanisms of action-of natural bioactive dietary flavonoids with the potential for targeting SARS-CoV-2 and its variants. Notably, we present promising strategies (combination therapy, lead optimization, and drug delivery) to overcome the inherent deficiencies of natural dietary flavonoids, such as limited bioavailability and poor stability.

The brief overview, antivirus and anti-SARS-CoV-2 activity, quantitative methods, and pharmacokinetics of cepharanthine: a potential small-molecule drug against COVID-19

To effectively respond to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), an increasing number of researchers are focusing on the antiviral activity of cepharanthine (CEP), which is a clinically approved drug being used for over 70 years. This review aims to provide a brief overview of CEP and summarize its recent findings in quantitative analysis, pharmacokinetics, therapeutic potential, and mechanism in antiviral and anti-SARS-CoV-2 activity. Given its remarkable capacity against SARS-CoV-2 infection in vitro and in vivo, with its primary target organ being the lungs, and its good pharmacokinetic profile; mature and stable manufacturing technique; and its advantages of safety, effectiveness, and accessibility, CEP has become a promising drug candidate for treating COVID-19 despite being an old drug.

Triose Phosphate Isomerase Structure-Based Virtual Screening and In Vitro Biological Activity of Natural Products as Leishmania mexicana Inhibitors

Cutaneous leishmaniasis (CL) is a public health problem affecting more than 98 countries worldwide. No vaccine is available to prevent the disease, and available medical treatments cause serious side effects. Additionally, treatment failure and parasite resistance have made the development of new drugs against CL necessary. In this work, a virtual screening of natural products from the BIOFACQUIM and Selleckchem databases was performed using the method of molecular docking at the triosephosphate isomerase (TIM) enzyme interface of Leishmania mexicana (L. mexicana). Finally, the in vitro leishmanicidal activity of selected compounds against two strains of L. mexicana, their cytotoxicity, and selectivity index were determined. The top ten compounds were obtained based on the docking results. Four were selected for further in silico analysis. The ADME-Tox analysis of the selected compounds predicted favorable physicochemical and toxicological properties. Among these four compounds, S-8 (IC50 = 55 µM) demonstrated a two-fold higher activity against the promastigote of both L. mexicana strains than the reference drug glucantime (IC50 = 133 µM). This finding encourages the screening of natural products as new anti-leishmania agents.

Antiviral Effect of Candies Containing Persimmon-Derived Tannin against SARS-CoV-2 Delta Strain

Inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the mouth has the potential to reduce the spread of coronavirus disease 2019 (COVID-19), due to the virus being readily transmitted by dispersed saliva. Persimmon-derived tannin has strong antioxidant and antimicrobial activity owing to its strong adhesion to proteins, and it also exhibited antiviral effects against non-variant and Alpha-variant SARS-CoV-2 in our previous study. In this study, we first demonstrated the antiviral effects of persimmon-derived tannin against the Delta variant of SARS-CoV-2 in vitro via the plaque assay method. We then examined the effects of candy containing persimmon-derived tannin. Remarkably, the saliva samples provided by healthy volunteers while they were eating tannin-containing candy showed that the virus titers of the SARS-CoV-2 Delta variant were suppressed. In addition, we found that the SARS-CoV-2 viral load in saliva from patients with COVID-19 collected immediately after they had eaten the tannin-containing candy was below the level of detection via PCR for SARS-CoV-2. These data suggest that adding persimmon-derived tannin to candy and holding such candy in the mouth is an effective method for inactivating SARS-CoV-2 in saliva, and the application of this approach shows potential for inhibiting the transmission of COVID-19.

Synergistic Activity of Remdesivir-Nirmatrelvir Combination on a SARS-CoV-2 In Vitro Model and a Case Report

BACKGROUND

This study aims to investigate the activity of the remdesivir-nirmatrelvir combination against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and to report a case of Coronavirus Disease 2019 (COVID-19) cured with this combination.

METHODS

A Vero E6 cell-based infection assay was used to investigate the in vitro activity of the remdesivir-nirmatrelvir combination. The SARS-CoV-2 strains tested were 20A.EU1, BA.1 and BA.5. After incubation, a viability assay was performed. The supernatants were collected and used for viral titration. The Highest Single Agent (HSA) reference model was calculated. An HSA score >10 is considered synergic.

RESULTS

Remdesivir and nirmatrelvir showed synergistic activity at 48 and 72 h, with an HSA score of 52.8 and 28.6, respectively (p < 0.0001). These data were confirmed by performing supernatant titration and against the omicron variants: the combination reduced the viral titer better than the more active compound alone. An immunocompromised patient with prolonged and critical COVID-19 was successfully treated with remdesivir, nirmatrelvir/ritonavir, tixagevimab/cilgavimab and dexamethasone, with an excellent clinical-radiological response. However, she required further off-label prolonged therapy with nirmatrelvir/ritonavir until she tested negative.

CONCLUSIONS

Remdesivir-nirmatrelvir combination has synergic activity in vitro. This combination may have a role in immunosuppressed patients with severe COVID-19 and prolonged viral shedding.

Combination of Chinese herbal medicine and conventional western medicine for coronavirus disease 2019: a systematic review and meta-analysis

Objective

This study aimed to assess the efficacy and safety of Chinese herbal medicine (CHM) plus conventional western medicine (CWM) in comparison with CWM against COVID-19.

Methods

We searched eight electronic databases and three trial registers spanning from January 1, 2020 to May 18, 2023. We included randomized controlled trials (RCTs) comparing the effectiveness and safety of CHM plus CWM and CWM against COVID-19 in our study. The Cochrane Risk of Bias tool 2.0 (RoB2) was applied to evaluate the methodological quality of the included RCTs. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was employed to assess the certainty of evidence. Statistical analysis was implemented in R version 4.1.2.

Results

Our study included 50 RCTs involving 11,624 patients. In comparison with sole CWM, CHM plus CWM against COVID-19 significantly enhanced clinical effective rate (RR = 1.18, 95% CI [1.13, 1.22]), improved chest image (RR = 1.19, 95% CI [1.11, 1.28]), inhibited clinical deterioration (RR = 0.45, 95% CI [0.33, 0.60]), lowered mortality (RR = 0.53, 95% CI [0.40, 0.70]), and reduced the total score of TCM syndrome (SMD = -1.24, 95% CI [-1.82, -0.66]). SARS-CoV-2 nucleic acid conversion time (MD = -2.66, 95% CI [-3.88, -1.44]), duration of hospitalization (MD = -2.36, 95% CI [-3.89, -0.82]), and clinical symptom (fever, cough, fatigue, and shortness of breath) recovery times were shorter in CHM plus CWM groups than in CWM groups. Further, CHM plus CWM treatment was more conducive for some laboratory indicators returning to normal levels. No statistical difference was found in the incidence of total adverse reactions between the two groups (RR = 0.97, 95% CI [0.88, 1.07]). We assessed the risk of bias for 246 outcomes, and categorized 55 into "low risk", 151 into "some concerns", and 40 into "high risk". Overall, the certainty of the evidence ranged from moderate to very low.

Conclusions

Potentially, CHM listed in this study, as an adjunctive therapy, combining with CWM is an effective and safe therapy mode for COVID-19. However, more high-quality RCTs are needed to draw more accurate conclusions.

Clinical trial registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=293963.

Pharmacological Activity of Cepharanthine

Cepharanthine, a natural bisbenzylisoquinoline (BBIQ) alkaloid isolated from the plant Stephania Cephalantha Hayata, is the only bisbenzylisoquinoline alkaloid approved for human use and has been used in the clinic for more than 70 years. Cepharanthine has a variety of medicinal properties, including signaling pathway inhibitory activities, immunomodulatory activities, and antiviral activities. Recently, cepharanthine has been confirmed to greatly inhibit SARS-CoV-2 infection. Therefore, we aimed to describe the pharmacological properties and mechanisms of cepharanthine, mainly including antitumor, anti-inflammatory, anti-pathogen activities, inhibition of bone resorption, treatment of alopecia, treatment of snake bite, and other activities. At the same time, we analyzed and summarized the potential antiviral mechanism of cepharanthine and concluded that one of the most important anti-viral mechanisms of cepharanthine may be the stability of plasma membrane fluidity. Additionally, we explained its safety and bioavailability, which provides evidence for cepharanthine as a potential drug for the treatment of a variety of diseases. Finally, we further discuss the potential new clinical applications of cepharanthine and provide direction for its future development.

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.

Role of Natural Products in the Management of COVID-19: A Saudi Arabian Perspective

The coronavirus disease of 2019 (COVID-19) pandemic has resulted in an unprecedented circumstance that has never previously occurred. This has caused the Saudi Arabian people to recognize the necessity of preventive measures and explore alternative systems, such as using natural products (NPs), for treating their infection. Therefore, the specific objectives of this study were to explore the factors that influence the selection of NPs for COVID-19 management and to know the outcome of using NPs in COVID-19 infection management. This observational cross-sectional study was conducted in Saudi Arabia between February and April 2022. The validated pretested questionnaire was distributed among different regions of the country via a purposive snowball sampling procedure. Both descriptive statistics and stepwise regression analyses were carried out to evaluate the parameters related to the use of medicinal plants for the prevention of COVID-19 and the treatment of respiratory symptoms during the pandemic. The data obtained were statistically analyzed using IBM SPSS Statistics for Windows, version 25 (IBM Corp., Armonk, NY, USA). Of the 677 participants, 65% reported using NPs for themselves or family members during COVID-19. Utilizing NPs is always given priority by a significant (p < 0.001) percentage of survey respondents. Further, a highly significant (p < 0.001) percentage of participants felt that using NPs reduced their COVID-19 symptoms without having any remarkable (p < 0.001) adverse effects. Family and friends (59%) were the most frequent sources of information about utilizing NPs, followed by personal experience (41%). Honey (62.7%) and ginger (53.8%) were the most utilized NP among participants. Moreover, black seeds, garlic and turmeric were used by 40.5%, 37.7% and 26.3% of the surveyors, respectively. Those who used NPs before COVID-19 were 72.9% more likely to use them during COVID-19. NPs are more likely to be used by 75% of people who live in the central part of the country and whose families prefer it. This is true even if other factors are considered, such as the practice of using NPs along with traditional therapies and the fact that some participants' families prefer it. Our findings show that NPs were commonly used to treat COVID-19 infection among Saudi Arabian residents. Close friends and family members mainly encouraged the use of NPs. Overall, the use of NPs was high among those who participated in our study; such practices are strongly impacted by society. It is essential to promote extensive studies to improve the recognition and accessibility of these products. Authorities should also educate the people about the benefits and risks of using commonly used NPs, especially those reported in this study.

Recent Developments and Future Perspectives of Vaccines and Therapeutic Agents against SARS-CoV2 Using the BCOV_S1_CTD of the S Protein

Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, the virus kept developing and mutating into different variants over time, which also gained increased transmissibility and spread in populations at a higher pace, culminating in successive waves of COVID-19 cases. The scientific community has developed vaccines and antiviral agents against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease. Realizing that growing SARS-CoV-2 variations significantly impact the efficacy of antiviral therapies and vaccines, we summarize the appearance and attributes of SARS-CoV-2 variants for future perspectives in drug design, providing up-to-date insights for developing therapeutic agents targeting the variants. The Omicron variant is among the most mutated form; its strong transmissibility and immune resistance capacity have prompted international worry. Most mutation sites currently being studied are in the BCOV_S1_CTD of the S protein. Despite this, several hurdles remain, such as developing vaccination and pharmacological treatment efficacies for emerging mutants of SARS-CoV-2 strains. In this review, we present an updated viewpoint on the current issues faced by the emergence of various SARS-CoV-2 variants. Furthermore, we discuss the clinical studies conducted to assist the development and dissemination of vaccines, small molecule therapeutics, and therapeutic antibodies having broad-spectrum action against SARS-CoV-2 strains.

Luteolin Isolated from Juncus acutus L., a Potential Remedy for Human Coronavirus 229E

The COVID-19 pandemic, caused by SARS-CoV-2, addressed the lack of specific antiviral drugs against coronaviruses. In this study, bioguided fractionation performed on both ethyl acetate and aqueous sub-extracts of Juncus acutus stems led to identifying luteolin as a highly active antiviral molecule against human coronavirus HCoV-229E. The apolar sub-extract (CH₂Cl₂) containing phenanthrene derivatives did not show antiviral activity against this coronavirus. Infection tests on Huh-7 cells, expressing or not the cellular protease TMPRSS2, using luciferase reporter virus HCoV-229E-Luc showed that luteolin exhibited a dose-dependent inhibition of infection. Respective IC₅₀ values of 1.77 µM and 1.95 µM were determined. Under its glycosylated form (luteolin-7-O-glucoside), luteolin was inactive against HCoV-229E. Time of addition assay showed that utmost anti-HCoV-229E activity of luteolin was achieved when added at the post-inoculation step, indicating that luteolin acts as an inhibitor of the replication step of HCoV-229E. Unfortunately, no obvious antiviral activity for luteolin was found against SARS-CoV-2 and MERS-CoV in this study. In conclusion, luteolin isolated from Juncus acutus is a new inhibitor of alphacoronavirus HCoV-229E.

Efficacy of Remdesivir and Neutralizing Monoclonal Antibodies in Monotherapy or Combination Therapy in Reducing the Risk of Disease Progression in Elderly or Immunocompromised Hosts Hospitalized for COVID-19: A Single Center Retrospective Study

INTRODUCTION

Remdesivir (REM) and monoclonal antibodies (mAbs) could alleviate severe COVID-19 in at-risk outpatients. However, data on their use in hospitalized patients, particularly in elderly or immunocompromised hosts, are lacking.

METHODS

All consecutive patients hospitalized with COVID-19 at our unit from 1 July 2021 to 15 March 2022 were retrospectively enrolled. The primary outcome was the progression to severe COVID-19 (P/F < 200). Descriptive statistics, a Cox univariate-multivariate model, and an inverse probability treatment-weighted (IPTW) analysis were performed.

RESULTS

Overall, 331 subjects were included; their median (q1-q3) age was 71 (51-80) years, and they were males in 52% of the cases. Of them, 78 (23%) developed severe COVID-19. All-cause in-hospital mortality was 14%; it was higher in those with disease progression (36% vs. 7%, p < 0.001). REM and mAbs resulted in a 7% (95%CI = 3-11%) and 14% (95%CI = 3-25%) reduction in the risk of severe COVID-19, respectively, after adjusting the analysis with the IPTW. In addition, by evaluating only immunocompromised hosts, the combination of REM and mAbs was associated with a significantly lower incidence of severe COVID-19 (aHR = 0.06, 95%CI = 0.02-0.77) when compared with monotherapy.

CONCLUSIONS

REM and mAbs may reduce the risk of COVID-19 progression in hospitalized patients. Importantly, in immunocompromised hosts, the combination of mAbs and REM may be beneficial.

Remdesivir Use in the Real-World Setting: An Overview of Available Evidence

In the years of Coronavirus Disease 2019 (COVID-19), various treatment options have been utilized. COVID-19 continues to circulate in the global population, and the evolution of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has posed significant challenges to the treatment and prevention of infection. Remdesivir (RDV), an anti-viral agent with in vitro efficacy against coronaviruses, is a potent and safe treatment as suggested by a plethora of in vitro and in vivo studies and clinical trials. Emerging real-world data have confirmed its effectiveness, and there are currently datasets evaluating its efficacy and safety against SARS-CoV-2 infections in various clinical scenarios, including some that are not in the SmPC recommendations according for COVID-19 pharmacotherapy. Remdesivir increases the chance of recovery, reduces progression to severe disease, lowers mortality rates, and exhibits beneficial post-hospitalization outcomes, especially when used early in the course of the disease. Strong evidence suggests the expansion of remdesivir use in special populations (e.g., pregnancy, immunosuppression, renal impairment, transplantation, elderly and co-medicated patients) where the benefits of treatment outweigh the risk of adverse effects. In this article, we attempt to overview the available real-world data of remdesivir pharmacotherapy. With the unpredictable course of COVID-19, we need to utilize all available knowledge to bridge the gap between clinical research and clinical practice and be sufficiently prepared for the future.

Efficacy analysis and research progress of complementary and alternative medicines in the adjuvant treatment of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has impacted human lifestyles around the world, causing huge distress in terms of public health systems, emergency response capacity and economic development. The causative agent of COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with respiratory involvement, cardiovascular-related diseases, and ultimately causes multiple organ failure and death in severely affected individuals. Thus, effective prevention or early treatment of COVID-19 is critical. An effective vaccine offers a way out of the pandemic for governments, the scientific community and people worldwide, but we still lack effective drug therapies, including treatments for the prevention and treatment of COVID-19. This had led to a high global demand for many complementary and alternative medicines (CAMs). Moreover, many healthcare providers are now requesting information about CAMs that prevent, relieve, or treat the symptoms of COVID-19 and even alleviate vaccine-related side effects. Experts and scholars must therefore become familiar with the use of CAMs in COVID-19, current research directions and effectiveness of CAMs for COVID-19. This narrative review updates the current status and research worldwide on the use of CAMs for COVID-19. The review provides reliable evidence on theoretical viewpoints and therapeutic efficacies of CAM combinations, and evidence in support of the therapeutic strategy of Taiwan Chingguan Erhau (NRICM102) against moderate-to-severe novel coronavirus infectious disease in Taiwan.

Impact of Dexamethasone on the Pathogen Profile of Critically Ill COVID-19 Patients

BACKGROUND

Even though several therapeutic options are available, COVID-19 is still lacking a specific treatment regimen. One potential option is dexamethasone, which has been established since the early beginnings of the pandemic. The aim of this study was to determine its effects on the microbiological findings in critically ill COVID-19 patients.

METHODS

A multi-center, retrospective study was conducted, in which all the adult patients who had a laboratory-confirmed (PCR) SARS-CoV-2 infection and were treated on intensive care units in one of twenty hospitals of the German Helios network between February 2020-March 2021 were included. Two cohorts were formed: patients who received dexamethasone and those who did not, followed by two subgroups according to the application of oxygen: invasive vs. non-invasive.

RESULTS

The study population consisted of 1.776 patients, 1070 of whom received dexamethasone, and 517 (48.3%) patients with dexamethasone were mechanically ventilated, compared to 350 (49.6%) without dexamethasone. Ventilated patients with dexamethasone were more likely to have any pathogen detection than those without (p < 0.026; OR = 1.41; 95% CI 1.04-1.91). A significantly higher risk for the respiratory detection of Klebsiella spp. (p = 0.016; OR = 1.68 95% CI 1.10-2.57) and for Enterobacterales (p = 0.008; OR = 1.57; 95% CI 1.12-2.19) was found for the dexamethasone cohort. Invasive ventilation was an independent risk factor for in-hospital mortality (p < 0.01; OR = 6.39; 95% CI 4.71-8.66). This risk increased significantly in patients aged 80 years or older by 3.3-fold (p < 0.01; OR = 3.3; 95% CI 2.02-5.37) when receiving dexamethasone.

CONCLUSION

Our results show that the decision to treat COVID-19 patients with dexamethasone should be a matter of careful consideration as it involves risks and bacterial shifts.

Effectiveness, Tolerability and Prescribing Choice of Antiviral Molecules Molnupiravir, Remdesivir and Nirmatrelvir/r: A Real-World Comparison in the First Ten Months of Use

In 2022, three antiviral drugs-molnupiravir, remdesivir and nirmatrelvir/ritonavir-were introduced for treatment of mild-to-moderate COVID-19 in high-risk patients. The aim of this study is the evaluation of their effectiveness and tolerability in a real-life setting. A single-center observational study was set up, with the involvement of 1118 patients, with complete follow-up data, treated between the 5th of January and the 3rd of October 2022 at Santa Maria Goretti's hospital in Latina, Central Italy. A univariable and a multivariable analysis were performed on clinical and demographic data and composite outcome, the persistence of symptoms at 30 days and time to negativization, respectively. The three antivirals showed a similar effectiveness in containing the progression of the infection to severe COVID-19 and a good tolerability in the absence of serious adverse effects. Persistence of symptoms after 30 days was more common in females than males and less common in patients treated with molnupiravir and nirmatrelvir/r. The availability of different antiviral molecules is a strong tool and, if correctly prescribed, they can have a significant role in changing the natural history of infection for frail persons, in which vaccination could be not sufficient for the prevention of severe COVID-19.

Serial viral load analysis by DDPCR to evaluate FNC efficacy and safety in the treatment of mild cases of COVID-19

Introduction

The SARS-CoV-2 outbreak has threatened the human population globally as the numbers of reinfection cases even after large-scale vaccination. Trials have been carried out to find drugs effective in fighting the disease, as COVID-19 is being considered a treatable disease only after we have antivirals. A clinical candidate originally developed for HIV treatment, AZVUDINE (FNC), is a promising drug in the treatment of COVID-19.

Methods

To predict the clinical outcome of COVID-19, we examined the course of viral load, every 48 h, by RT-PCR, and disease severity using an antiviral drug, FNC, with 281 participants. A randomized clinical trial was performed to evaluate the efficacy of FNC added to standard treatment, compared with placebo group added to standard treatment, for patients with mild COVID-19. RT-qPCR and ddPCR were applied to estimate the viral load in samples from patients. Also, the clinical improvement was evaluated as well as the liver and kidney function.

Results and discussion

Notably, the FNC treatment in the mild COVID-19 patients may shorten the time of the nucleic acid negative conversion (NANC) versus placebo group. In addition, the FNC was effective in reducing the viral load of these participants. The present clinical trial results showed that the FNC accelerate the elimination of the virus in and could reduce treatment time of mild patients and save a lot of medical resources, making it a strong candidate for the outpatient and home treatment of COVID-19.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT05033145, identifier NCT05033145.

Potential Anti-SARS-CoV-2 Prodrugs Activated by Phosphorylation and Their Role in the Aged Population

The COVID-19 pandemic has flared across every part of the globe and affected populations from different age groups differently. People aged from 40 to 80 years or older are at an increased risk of morbidity and mortality due to COVID-19. Therefore, there is an urgent requirement to develop therapeutics to decrease the risk of the disease in the aged population. Over the last few years, several prodrugs have demonstrated significant anti-SARS-CoV-2 effects in in vitro assays, animal models, and medical practice. Prodrugs are used to enhance drug delivery by improving pharmacokinetic parameters, decreasing toxicity, and attaining site specificity. This article discusses recently explored prodrugs such as remdesivir, molnupiravir, favipiravir, and 2-deoxy-D-glucose (2-DG) and their implications in the aged population, as well as investigating recent clinical trials.

Plants as Biofactories for Therapeutic Proteins and Antiviral Compounds to Combat COVID-19

The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had a profound impact on the world's health and economy. Although the end of the pandemic may come in 2023, it is generally believed that the virus will not be completely eradicated. Most likely, the disease will become an endemicity. The rapid development of vaccines of different types (mRNA, subunit protein, inactivated virus, etc.) and some other antiviral drugs (Remdesivir, Olumiant, Paxlovid, etc.) has provided effectiveness in reducing COVID-19's impact worldwide. However, the circulating SARS-CoV-2 virus has been constantly mutating with the emergence of multiple variants, which makes control of COVID-19 difficult. There is still a pressing need for developing more effective antiviral drugs to fight against the disease. Plants have provided a promising production platform for both bioactive chemical compounds (small molecules) and recombinant therapeutics (big molecules). Plants naturally produce a diverse range of bioactive compounds as secondary metabolites, such as alkaloids, terpenoids/terpenes and polyphenols, which are a rich source of countless antiviral compounds. Plants can also be genetically engineered to produce valuable recombinant therapeutics. This molecular farming in plants has an unprecedented opportunity for developing vaccines, antibodies, and other biologics for pandemic diseases because of its potential advantages, such as low cost, safety, and high production volume. This review summarizes the latest advancements in plant-derived drugs used to combat COVID-19 and discusses the prospects and challenges of the plant-based production platform for antiviral agents.

Chemical Characterization and Leishmanicidal Activity In Vitro and In Silico of Natural Products Obtained from Leaves of Vernonanthura brasiliana (L.) H. Rob (Asteraceae)

Vernonanthura brasiliana (L.) H. Rob is a medicinal plant used for the treatment of several infections. This study aimed to evaluate the antileishmanial activity of V. brasiliana leaves using in vitro and in silico approaches. The chemical composition of V. brasiliana leaf extract was determined through liquid chromatography-mass spectrometry (LC-MS). The inhibitory activity against Leishmania amazonensis promastigote was evaluated by the MTT method. In silico analysis was performed using Lanosterol 14alpha-demethylase (CYP51) as the target. The toxicity analysis was performed in RAW 264.7 cells and Tenebrio molitor larvae. LC-MS revealed the presence of 14 compounds in V. brasiliana crude extract, including flavonoids, flavones, sesquiterpene lactones, and quinic acids. Eriodictol (ΔGbind = -9.0), luteolin (ΔGbind = -8.7), and apigenin (ΔGbind = -8.6) obtained greater strength of molecular interaction with lanosterol demethylase in the molecular docking study. The hexane fraction of V. brasiliana showed the best leishmanicidal activity against L. amazonensis in vitro (IC50 12.44 ± 0.875 µg·mL-1) and low cytotoxicity in RAW 264.7 cells (CC50 314.89 µg·mL-1, SI = 25.30) and T. molitor larvae. However, the hexane fraction and Amphotericin-B had antagonistic interaction (FICI index ≥ 4.0). This study revealed that V. brasiliana and its metabolites are potential sources of lead compounds for drugs for leishmaniasis treatment.

Identifying potential pharmacological targets and molecular pathways of Meliae cortex for COVID-19 therapy

Coronavirus disease-19 (COVID-19), caused by SARS-CoV-2, has contributed to a significant increase in mortality. Proinflammatory cytokine-mediated cytokine release syndrome (CRS) contributes significantly to COVID-19. Meliae cortex has been reported for its several ethnomedical applications in the Chinese Pharmacopoeia. In combination with other traditional Chinese medicines (TCM), the Meliae cortex suppresses coronavirus. Due to its phytoconstituents and anti-inflammatory capabilities, we postulated that the Meliae cortex could be a potential therapeutic for treating COVID-19. The active phytonutrients, molecular targets, and pathways of the Meliae cortex have not been explored yet for COVID-19 therapy. We performed network pharmacology analysis to determine the active phytoconstituents, molecular targets, and pathways of the Meliae cortex for COVID-19 treatment. 15 active phytonutrients of the Meliae cortex and 451 their potential gene targets were retrieved from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) and SwissTargetPrediction website tool, respectively. 1745 COVID-19-related gene targets were recovered from the GeneCards. 104 intersection gene targets were determined by performing VENNY analysis. Using the DAVID tool, gene ontology (GO) and KEGG pathway enrichment analysis were performed on the intersection gene targets. Using the Cytoscape software, the PPI and MCODE analyses were carried out on the intersection gene targets, which resulted in 41 potential anti-COVID-19 core targets. Molecular docking was performed with AutoDock Vina. The 10 anti-COVID-19 core targets (AKT1, TNF, HSP90AA1, IL-6, mTOR, EGFR, CASP3, HIF1A, MAPK3, and MAPK1), three molecular pathways (the PI3K-Akt signaling pathway, the HIF-1 signaling pathway, and the pathways in cancer) and three active phytonutrients (4,8-dimethoxy-1-vinyl-beta-carboline, Trichilinin D, and Nimbolin B) were identified as molecular targets, molecular pathways, and key active phytonutrients of the Meliae cortex, respectively that significantly contribute to alleviating COVID-19. Molecular docking analysis further corroborated that three Meliae cortex's key active phytonutrients may ameliorate COVID-19 disease by modulating identified targets. Hence, this research offers a solid theoretic foundation for the future development of anti-COVID-19 therapeutics based on the phytonutrients of the Meliae cortex.

A Synergistic pH-Responsive Serum Albumin-Based Drug Delivery System Loaded with Doxorubicin and Pentacyclic Triterpene Betulinic Acid for Potential Treatment of NSCLC

Nanosized drug delivery systems (DDS) have been studied as a novel strategy against cancer due to their potential to simultaneously decrease drug inactivation and systemic toxicity and increase passive and/or active drug accumulation within the tumor(s). Triterpenes are plant-derived compounds with interesting therapeutic properties. Betulinic acid (BeA) is a pentacyclic triterpene that has great cytotoxic activity against different cancer types. Herein, we developed a nanosized protein-based DDS of bovine serum albumin (BSA) as the drug carrier combining two compounds, doxorubicin (Dox) and the triterpene BeA, using an oil-water-like micro-emulsion method. We used spectrophotometric assays to determine protein and drug concentrations in the DDS. The biophysical properties of these DDS were characterized using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy, confirming nanoparticle (NP) formation and drug loading into the protein structure, respectively. The encapsulation efficiency was 77% for Dox and 18% for BeA. More than 50% of both drugs were released within 24 h at pH 6.8, while less drug was released at pH 7.4 in this period. Co-incubation viability assays of Dox and BeA alone for 24 h demonstrated synergistic cytotoxic activity in the low μM range against non-small-cell lung carcinoma (NSCLC) A549 cells. Viability assays of the BSA-(Dox+BeA) DDS demonstrated a higher synergistic cytotoxic activity than the two drugs with no carrier. Moreover, confocal microscopy analysis confirmed the cellular internalization of the DDS and the accumulation of the Dox in the nucleus. We determined the mechanism of action of the BSA-(Dox+BeA) DDS, confirming S-phase cell cycle arrest, DNA damage, caspase cascade activation, and downregulation of epidermal growth factor receptor (EGFR) expression. This DDS has the potential to synergistically maximize the therapeutic effect of Dox and diminish chemoresistance induced by EGFR expression using a natural triterpene against NSCLC.

An Overview of Potential Natural Photosensitizers in Cancer Photodynamic Therapy

Cancer is one of the main causes of death worldwide. There are several different types of cancer recognized thus far, which can be treated by different approaches including surgery, radiotherapy, chemotherapy or a combination thereof. However, these approaches have certain drawbacks and limitations. Photodynamic therapy (PDT) is regarded as an alternative noninvasive approach for cancer treatment based on the generation of toxic oxygen (known as reactive oxygen species (ROS)) at the treatment site. PDT requires photoactivation by a photosensitizer (PS) at a specific wavelength (λ) of light in the vicinity of molecular oxygen (singlet oxygen). The cell death mechanisms adopted in PDT upon PS photoactivation are necrosis, apoptosis and stimulation of the immune system. Over the past few decades, the use of natural compounds as a photoactive agent for the selective eradication of neoplastic lesions has attracted researchers' attention. Many reviews have focused on the PS cell death mode of action and photonanomedicine approaches for PDT, while limited attention has been paid to the photoactivation of phytocompounds. Photoactivation is ever-present in nature and also found in natural plant compounds. The availability of various laser light setups can play a vital role in the discovery of photoactive phytocompounds that can be used as a natural PS. Exploring phytocompounds for their photoactive properties could reveal novel natural compounds that can be used as a PS in future pharmaceutical research. In this review, we highlight the current research regarding several photoactive phytocompound classes (furanocoumarins, alkaloids, poly-acetylenes and thiophenes, curcumins, flavonoids, anthraquinones, and natural extracts) and their photoactive potential to encourage researchers to focus on studies of natural agents and their use as a potent PS to enhance the efficiency of PDT.

Biobran/MGN-3, an Arabinoxylan Rice Bran, Protects against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): An In Vitro and In Silico Study

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 2019 (COVID-19), poses a serious global public health threat for which there is currently no satisfactory treatment. This study examines the efficacy of Biobran/MGN-3 against SARS-CoV-2. Biobran is an arabinoxylan rice bran that has been shown to significantly inhibit the related influenza virus in geriatric subjects. Here, Biobran's anti-SARS-CoV-2 activity was assessed using MTT and plaque reduction assays, RT-PCR, ELISA techniques, and measurements of SARS-CoV-2-related gene expression and protein levels. For Vero E6 cells infected with SARS-CoV-2, Biobran reduced the viral load by 91.9% at a dose of 100 μg/mL, it reduced viral counts (PFU/mL) by 90.6% at 50 μg/mL, and it exhibited a significant selectivity index (EC₅₀/IC₅₀) of 22.5. In addition, Biobran at 10 μg/mL inhibited papain-like proteinase (PLpro) by 87% and ACE2 SARS-CoV-2 S-protein RBD by 90.5%, and it significantly suppressed SARS-CoV-2 gene expression, down-regulating E-gene and RdRp gene expression by 93% each at a dose of 50 μg/mL and inhibiting the E-protein by 91.3%. An in silico docking study was also performed to examine the protein-protein interaction (PPI) between SARS-CoV-2 RBD and DC-SIGN as well as between serine carboxypeptidase and papain-like protease PLpro. Serine carboxypeptidase, an active ingredient in Biobran, was found to interfere with the binding of SARS-CoV-2 to its receptor DC-SIGN on Vero cells, thus preventing the cell entry of SARS-CoV-2. In addition, it impairs the viral replication cycle by binding to PLpro. We conclude that Biobran possesses potent antiviral activity against SARS-CoV-2 in vitro and suggest that Biobran may be able to prevent SARS-CoV-2 infection. This warrants further investigation in clinical trials.

In Vitro Antiviral Evaluations of Coldmix®: An Essential Oil Blend against SARS-CoV-2

Coldmix® is a commercially available Eucalyptus aetheroleum and, Abies aetheroleum blend for medicinal applications. In this present study, the in vitro antiviral potential of Coldmix®, and its major constituents 1,8-cineole and α-pinene were evaluated by using the in vitro ACE2 enzyme inhibition assay as well as the direct contact test against SARS-CoV-2. The observed ACE2 enzyme inhibitory activity of Coldmix®, 1,8-cineole, and α-pinene were 72%, 88%, and 80%, respectively; whereas in the direct contact test in the vapor phase, the destruction of the virus was 79.9% within 5 min and 93.2% in the 30th min, respectively. In a similar Coldmix® vapor phase setup using the in vitro cytotoxicity cell assay, E6 VERO healthy cells were experimentally not affected by toxicity. According to the promising initial antiviral results of Coldmix® and the individually tested constituents, detailed further in vivo evaluation using different virus classes is suggested.

Traditional Tibetan medicine to fight against COVID-19: Basic theory and therapeutic drugs

The Coronavirus Diseases 2019 (COVID-19) has been rapidly spreading globally and has caused severe harm to the health of people and a substantial social burden. In response to this situation, experts around the world have considered various treatments, including the use of traditional medicine. Traditional Tibetan medicine (TTM), one of the traditional medicines in China, has played an important role in the treatment of infectious diseases in history. It has formed a solid theoretical foundation and accumulated rich experience in the treatment of infectious diseases. In this review, we provide a comprehensive introduction to the basic theory, treatment strategies, and commonly used drugs of TTM for the treatment of COVID-19. In addition, the efficacies and potential mechanisms of these TTM drugs against COVID-19 are discussed based on available experimental data. This review may provide important information for the basic research, clinical application and drug development of traditional medicines for the treatment of COVID-19 or other infectious diseases. More pharmacological studies are needed to reveal the therapeutic mechanisms and active ingredients of TTM drugs in the treatment of COVID-19.

Towards a transactional medicine approach to combating global emerging pathogens: the case of COVID-19

When the COVID-19 pandemic struck and China reported the first case to the World Health Organization in December 2019, there was no evidence-based treatment to combat it. With the catastrophic situation that followed, materialised by a considerable number of deaths, researchers, doctors, traditional healers, and governments of all nations committed themselves to find therapeutic solutions, including preventive and curative. There are effective treatments offered both by modern medicine and traditional medicine for COVID-19 today. However, other therapeutic proposals have not been approved due to the lack of effectiveness and scientific rigour during their development process. Proponents of modern medicine prefer biomedical therapies while in some countries, traditional treatments are used regularly because of their availability, affordability and satisfaction they bring to the population. In this paper, we propose a transactional medicine approach where the interaction between traditional and modern medicine produces a change. With this approach, the promoters of traditional medicine and those of modern medicine will be able to acquire knowledge through the experience produced by their encounters. Transactional medicine aims to be a model for decolonising medicine and recognising the value of both traditional and modern medicine in the fight against COVID-19 and other global emerging pathogens.