Randomized, double-blind, placebo-controlled clinical trial to assess the safety and effectiveness of a novel dual-action oral topical formulation against upper respiratory infections

From the "One-Molecule, One-Target, One-Disease" Concept towards Looking for Multi-Target Therapeutics for Treating Non-Polio Enterovirus (NPEV) Infections

Non-polio enteroviruses (NPEVs), namely coxsackieviruses (CV), echoviruses (E), enteroviruses (EV), and rhinoviruses (RV), are responsible for a wide variety of illnesses. Some infections can progress to life-threatening conditions in children or immunocompromised patients. To date, no treatments have been approved. Several molecules have been evaluated through clinical trials without success. To overcome these failures, the multi-target directed ligand (MTDL) strategy could be applied to tackle enterovirus infections. This work analyzes registered clinical trials involving antiviral drugs to highlight the best candidates and develops filters to apply to a selection for MTDL synthesis. We explicitly stated the methods used to answer the question: which solution can fight NPEVs effectively? We note the originality and relevance of this proposal in relation to the state of the art in the enterovirus-inhibitors field. Several combinations are possible to broaden the antiviral spectrum and potency. We discuss data related to the virus and data related to each LEAD compound identified so far. Overall, this study proposes a perspective on different strategies to overcome issues identified in clinical trials and evaluate the "MTDL" potential to improve the efficacy of drugs, broaden the antiviral targets, possibly reduce the adverse effects, drug design costs and limit the selection of drug-resistant virus variants.

Antimicrobial cetylpyridinium chloride causes functional inhibition of mitochondria as potently as canonical mitotoxicants, nanostructural disruption of mitochondria, and mitochondrial Ca2+ efflux in living rodent and primary human cells

People are exposed to high concentrations of antibacterial agent cetylpyridinium chloride (CPC) via food and personal care products, despite little published information regarding CPC effects on eukaryotes. Here, we show that low-micromolar CPC exposure, which does not cause cell death, inhibits mitochondrial ATP production in primary human keratinocytes, mouse NIH-3T3 fibroblasts, and rat RBL-2H3 immune mast cells. ATP inhibition via CPC (EC50 1.7 μM) is nearly as potent as that caused by canonical mitotoxicant CCCP (EC50 1.2 μM). CPC inhibition of oxygen consumption rate (OCR) tracks with that of ATP: OCR is halved due to 1.75 μM CPC in RBL-2H3 cells and 1.25 μM in primary human keratinocytes. Mitochondrial [Ca2+] changes can cause mitochondrial dysfunction. Here we show that CPC causes mitochondrial Ca2+ efflux from mast cells via an ATP-inhibition mechanism. Using super-resolution microscopy (fluorescence photoactivation localization) in live cells, we have discovered that CPC causes mitochondrial nanostructural defects in live cells within 60 min, including the formation of spherical structures with donut-like cross section. This work reveals CPC as a mitotoxicant despite widespread use, highlighting the importance of further research into its toxicological safety.

Cetylpyridinium chloride and chlorhexidine show antiviral activity against Influenza A virus and Respiratory Syncytial virus in vitro

BACKGROUND

The oral cavity is the site of entry and replication for many respiratory viruses. Furthermore, it is the source of droplets and aerosols that facilitate viral transmission. It is thought that appropriate oral hygiene that alters viral infectivity might reduce the spread of respiratory viruses and contribute to infection control.

MATERIALS AND METHODS

Here, we analyzed the antiviral activity of cetylpyridinium chloride (CPC), chlorhexidine (CHX), and three commercial CPC and CHX-containing mouthwash preparations against the Influenza A virus and the Respiratory syncytial virus. To do so the aforementioned compounds and preparations were incubated with the Influenza A virus or with the Respiratory syncytial virus. Next, we analyzed the viability of the treated viral particles.

RESULTS

Our results indicate that CPC and CHX decrease the infectivity of both the Influenza A virus and the Respiratory Syncytial virus in vitro between 90 and 99.9% depending on the concentration. Likewise, CPC and CHX-containing mouthwash preparations were up to 99.99% effective in decreasing the viral viability of both the Influenza A virus and the Respiratory syncytial virus in vitro.

CONCLUSION

The use of a mouthwash containing CPC or CHX alone or in combination might represent a cost-effective measure to limit infection and spread of enveloped respiratory viruses infecting the oral cavity, aiding in reducing viral transmission. Our findings may stimulate future clinical studies to evaluate the effects of CPC and CHX in reducing viral respiratory transmissions.

Effects of different antiviral mouthwashes on the surface roughness, hardness, and color stability of composite CAD/CAM materials

OBJECTIVE

To evaluate the effect of COVID-19 preventive mouthwashes on the surface hardness, surface roughness (Ra), and color change (ΔE) of three different polymer-based composite CAD/CAM materials (Vita Enamic (ENA), Grandio Block (GB), Lava Ultimate (LU)).

METHODS

A total of 100 rectangular-shaped specimens with dimensions of 2 mm × 7 mm × 12 mm were obtained by sectioning three different CAD/CAM blocks and randomly divided into five subgroups according to the 30 days of mouthwash immersion protocol as follows: Control: artificial saliva, PVP-I: 1% povidone-iodine, HP: 1.5% hydrogen peroxide, CPC: mouthwash containing 0.075% cetylpyridinium chloride, EO: mouthwash containing essential oils. Microhardness, Ra, and ΔE values were measured at baseline and after 30 days of immersion protocols. Data were analyzed using the Wald Chi-square, two-way ANOVA, and post hoc Tukey tests.

RESULTS

The independent factors (materials and solutions) significantly influenced the microhardness and color (p < 0.001). Ra of the materials was not affected by any of the mouthwashes (p > 0.05). The microhardness and color of each material varied significantly after immersion in PvP-I and HP (p < 0.05). The highest percentage change in microhardness, Ra, and ΔE was found in LU immersed in PvP-I and HP mouthwashes, while the lowest change was found in ENA groups (p < 0.05).

CONCLUSION

Within the limitations of this study, it was found that the surface hardness and color of tested polymer-based composite CAD/CAM materials are susceptible to degradation and change after 30 days of immersion in 1% PvP-I and 1.5% HP mouthwashes.

Hyperthermia inhibits cellular function and induces immunogenic cell death in renal cell carcinoma

BACKGROUND

In recent years, hyperthermia has been widely applied as a novel strategy for cancer treatment due to its multiple antitumour effects. In particular, the potential influences of hyperthermia on the tumour immune microenvironment may improve the efficacy of immunotherapies. However, the effect of hyperthermia on renal cell carcinoma (RCC) has not been well characterized until now.

METHODS

In the present study, we primarily evaluated the effects of hyperthermia on cellular function via cellular proliferation, migration, invasion and apoptosis assays. In addition, the influence of hyperthermia on the immunogenicity of RCC cells was analysed using flow cytometry analysis, enzyme-linked immunosorbent assays, and immunofluorescent (IF) staining.

RESULTS

Our results demonstrate that hyperthermia significantly inhibits RCC cell proliferation, migration, and invasion and promotes cell apoptosis. In addition, we verified that hyperthermia improves the immunogenicity of RCC cells by inducing immunogenic cell death.

CONCLUSION

Our findings suggest that hyperthermia is a promising therapeutic strategy for RCC.

Do Disinfectant Solutions during Gargling Reach the Pharynx?

INTRODUCTION

In times of COVID-19, gargling disinfectant is commonly used. Disinfectant solutions seem to decrease the infection's symptoms. For disinfection, several techniques are reported. So far, there are no data about the regions in the upper airways achieved by gargled fluid.

METHODS

Ten healthy volunteers without any dysphagia were investigated with a high-sensitivity flexible endoscopic evaluation of swallowing (hsFEES®) during and after gargling colored water. One volunteer repeated the gargling process in fast and real-time MRI.

RESULTS

In all cases, no color accumulation was detected on the posterior pharyngeal wall, epi- or hypopharynx during gargling. The MRI scans confirmed the results.

CONCLUSIONS

hsFEES® and fast MRI provide an insight into the gargling pattern. Data show that during gargling, the fluid covers the soft tissue in the oral cavity and the anterior part of the soft palate, but not the posterior pharyngeal wall nor the epi- and hypopharynx.

The role of the oral cavity in SARS-CoV-2- and other viral infections

OBJECTIVE

This study aims to review the role of the oral cavity in SARS-CoV-2- and other viral upper respiratory tract infections.

MATERIAL AND METHODS

Data reviewed in the text have been researched online and also reflect personal expertise.

RESULTS

Numerous respiratory and other viruses replicate in the oral cavity and are transmitted via aerosols (< 5 µm) and droplets (> 5 µm). SARS-CoV-2 replication has been documented in the upper airways as well as in oral mucosa and salivary glands. These sites are also virus reservoirs that can infect other organs, e.g., the lungs and gastrointestinal tract, as well as other individuals. Laboratory diagnosis of viruses in the oral cavity and upper airways focuses on real-time PCR; antigen tests are less sensitive. For screening and monitoring infections, nasopharyngeal and oral swabs are tested; saliva is a good and more comfortable alternative. Physical means like social distancing or masks have been proven successful to reduce the risk of infection. Both wet-lab and clinical studies confirm that mouth rinses are effective against SARS-CoV-2 and other viruses. Antiviral mouth rinses can inactivate all viruses that replicate in the oral cavity.

CONCLUSIONS

The oral cavity plays an important role in viral infections of the upper respiratory tract: it serves as a portal of entry, a site of replication, and a source of infection by droplets and aerosols. Physical means but also antiviral mouth rinses can help reduce the spread of viruses and contribute to infection control.

Preprocedural Viral Load Effects of Oral Antiseptics on SARS-CoV-2 in Patients with COVID-19: A Systematic Review

(1) There are limited clinical trials to support the effectiveness of mouth rinses when used as a preprocedural rinse against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This systematic review aims to evaluate the efficacy of antiseptic mouth rinses as a preprocedural rinse in reducing SARS-CoV-2 oral viral load in-vivo. (2) Methods: A literature search was conducted through November 2022 for the following databases: PubMed, Web of Science, Cochrane Library, and Google Scholar. The evaluated outcomes were quantitative changes in viral load and the statistical significance of that change after using antiseptic mouth rinses. (3) Results: 14 randomized controlled trials (RCT) were selected for risk of bias assessment and data extraction. (4) Conclusion: Within the limits of this systematic review, preprocedural mouth rinses may significantly reduce SARS-CoV-2 in the mouth, thus, reducing the viral particles available for airborne dispersion. Preprocedural mouth rinses may be an effective strategy for reducing airborne SARS-CoV-2 dispersion in the environment. Their use may be a preventive strategy to reduce the spread of COVID-19 in selected medical and healthcare facilities, including dental clinics. Potential preprocedural mouth rinses are identified for use as an integral part of safe practice for healthcare protocols. This systematic review was registered with the National Institute for Health Research, international prospective register of systematic reviews (PROSPERO): CRD42022315177.

Investigation of the impacts of simple electrolytes and hydrotrope on the interaction of ceftriaxone sodium with cetylpyridinium chloride at numerous study temperatures

Herein, interactions between cetylpyridinium chloride (CPC) and ceftriaxone sodium (CTS) were investigated applying conductivity technique. Impacts of the nature of additives (e.g. electrolytes or hydrotrope (HDT)), change of temperatures (from 298.15 to 323.15 K), and concentration variation of CTS/additives were assessed on the micellization of CPC + CTS mixture. The conductometric analysis of critical micelle concentration (CMC) with respect to the concentration reveals that the CMC values were increased with the increase in CTS concentration. In terms of using different mediums, CMC did not differ much with the increase in electrolyte salt (NaCl, Na2SO4) concentration, but increased significantly with the rise of HDT (NaBenz) amount. In the presence of electrolyte, CMC showed a gentle increment with temperature, while the HDT showed the opposite trend. Obtained result was further correlated with conventional thermodynamic relationship, where standard Gibb's free energy change ( Δ G m o ) , change of enthalpy ( Δ H m o ) , and change of entropy ( Δ S m o ) were utilized to investigate. The Δ G m o values were negative for all the mixed systems studied indicating that the micellization process was spontaneous. Finally, the stability of micellization was studied by estimating the intrinsic enthalpy gain (Δ H m o , ∗ ) and compensation temperature (Tc). Here, CPC + CTS mixed system showed more stability in Na2SO4 medium than the NaCl, while in NaBenz exhibited the lowest stability.

Efectividad de enjuagues bucales contra virus de la familia coronavirus

La aparición del virus Sars-CoV-2 y la enfermedad Covid-19 han provocado un estado de emergencia en el sistema de salud. Teniendo en cuenta el potencial de la saliva como material contaminante, la práctica odontológica fue una de las áreas que se vio afectada debido al uso de instrumentos que pueden esparcir aerosoles y salpicaduras que contienen microorganismos hacia el medio ambiente. Por esta razón, conociendo su potencial en la inactivación de patógenos, se propuso la utilización de enjuagues bucales en la práctica clínica previo a la realización de procedimientos dentales, sin embargo la evidencia no es clara respecto a su efectividad. Objetivo. Establecer el estado de evidencia actual del efecto de los enjuagues bucales sobre los coronavirus que se encuentran en cavidad. Métodos. Se realizó una revisión sistemática siguiendo todos los parámetros descritos en las DirectricesPRISMA basada en información obtenida en los buscadores Science direct, Pubmed y Dentistry and Oral Science Source. Los criterios de selección incluyeron estudios in vivo e in vitro de texto completo que evidenciaron la efectividad del enjuague bucal contra coronavirus. Resultados. Se obtuvieron 90 artículos, de los cuales sólo 12 cumplían con los criterios de inclusión,8 in vitro y 4 in vivo, que fueron sometidos a la evaluación de calidad metodológica utilizando la lista de verificación de evaluación crítica del JBI.  Conclusiones. Los resultados sugieren que la povidona yodada es efectiva para la inactivación del virus Sars-coV-2 en todas sus concentraciones.

The efficacy of mouthwashes in reducing SARS-CoV-2 viral loads in human saliva: A systematic review

This systematic review aimed to evaluate existing randomized controlled trials (RCT) and cohort studies on the efficacy of mouthwashes in reducing SARS-CoV-2 viral loads in human saliva. Searches with pertinent search terms were conducted in PubMed, MEDLINE, Scopus, and Web of Science databases for relevant records published up to Oct 15, 2022. Google Scholar and ProQuest were searched for grey literature. Manual searches were conducted as well for any pertinent articles. The protocol was prospectively registered at PROSPERO (CRD42022324894). Eligible studies were critically appraised for risk of bias and quality of evidence to assess the efficacy of mouthwash in reducing the SARS-CoV-2 viral load in human saliva. Eleven studies were included. The effect on viral load using various types of mouthwash was observed, including chlorhexidine (CHX), povidone-iodine (PI), cetylpyridinium chloride (CPC), hydrogen peroxide (HP), ß-cyclodextrin-citrox mouthwash (CDCM), and Hypochlorous acid (HCIO). Eight articles discussed CHX use. Five were found to be significant and three did not show any significant decrease in viral loads. Eight studies reviewed the use of PI, with five articles identifying a significant decrease in viral load, and three not showing a significant decrease in viral load. HP was reviewed in four studies, two studies identified significant viral load reductions, and two did not. CPC was reviewed in four studies, two of which identified significant viral load reductions, and two did not. CDCM was reviewed in one article which found a significant decrease in viral load reduction. Also, HCIO which was evaluated in one study indicated no significant difference in CT value. The current systematic review indicates that based on these eleven studies, mouthwashes are effective at reducing the SARS-CoV-2 viral load in human saliva. However, further studies should be performed on larger populations with different mouthwashes. The overall quality of evidence was high.

Virucidal activity and mechanism of action of cetylpyridinium chloride against SARS-CoV-2

Objective

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen causing the coronavirus disease 2019 (COVID-19) global pandemic. Recent studies have shown the importance of the throat and salivary glands as sites of virus replication and transmission. The viral host receptor, angiotensin-converting enzyme 2 (ACE2), is broadly enriched in epithelial cells of the salivary glands and oral mucosae. Oral care products containing cetylpyridinium chloride (CPC) as a bactericidal ingredient are known to exhibit antiviral activity against SARS-CoV-2 in vitro. However, the exact mechanism of action remains unknown.

Methods

This study examined the antiviral activity of CPC against SARS-CoV-2 and its inhibitory effect on the interaction between the viral spike (S) protein and ACE2 using an enzyme-linked immunosorbent assay.

Results

CPC (0.05%, 0.1% and 0.3%) effectively inactivated SARS-CoV-2 within the contact times (20 and 60 s) in directions for use of oral care products in vitro. The binding ability of both the S protein and ACE2 were reduced by CPC.

Conclusions

Our results suggest that CPC inhibits the interaction between S protein and ACE2, and thus, reduces infectivity of SARS-CoV-2 and suppresses viral adsorption.

Evaluation of Current Evidence on the Use of Oral Antiseptics Against SARS-CoV-2: A Narrative Review

AIMS AND OBJECTIVES

The detection of SARS-COV-2 in the oral cavity has generated endless claims about the efficacy of using oral mouthwashes to reduce viral load. This review aims to assess the current evidence on the use of oral antiseptics against SARS-CoV-2 and to assess the certainty of the evidence according to the GRADE system. The question this study focussed on was what is the efficacy of oral antiseptics against SARS-CoV-2?

MATERIALS AND METHODS

A bibliographic search was performed in Medline databases through PubMed, Science Direct, and Google Scholar (until February 2022), using search terms related to COVID-19 and oral antiseptics. Two independent researchers extracted the information from the articles included in an excel form. The identification and selection of the studies was carried out from August 2021 to February 2022.

RESULTS

It was found that oral antiseptics can have a potential beneficial effect on COVID-19, mainly in reducing viral load. However, these potential benefits are mainly based on in-vitro studies or clinical studies with various methodological limitations. At present, the certainty of the evidence is very low due to inconsistency (heterogeneity), moderate-to-high risk of bias, and imprecision of the results.

CONCLUSION

The certainty of the current evidence on the efficacy of oral antiseptics against SARS-CoV-2 is very low, mainly due to the methodological limitations of the studies. Therefore, for evidence-based decision-making about this intervention, clinical studies with greater methodological rigor are required. Oral antiseptics could present potential benefits in patients with COVID-19 mainly by reducing viral load. However, a careful and conscious evaluation of the evidence is required for decision-making in clinical practice.

Antiseptic Polymer-Surfactant Complexes with Long-Lasting Activity against SARS-CoV-2

Antiseptic polymer gel-surfactant complexes were prepared by incorporating the low-molecular-weight cationic disinfectant cetylpyridinium chloride into the oppositely charged, slightly cross-linked polymer matrices. Three types of polymers were used: copolymers of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate; copolymers of acrylamide and sodium methacrylate; copolymers of vinylpyrrolidone and sodium methacrylate. It was shown that the rate of the release of the cationic disinfectant from the oppositely charged polymer gels could be tuned in a fairly broad range by varying the concentration of the disinfectant, the degree of swelling, and degree of cross-linking of the gel and the content/type of anionic repeat units in the polymer matrix. Polymer-surfactant complexes were demonstrated to reduce SARS-CoV-2 titer by seven orders of magnitude in as little as 5 s. The complexes retained strong virucidal activity against SARS-CoV-2 for at least one week.

Cetylpyridinium chloride (CPC) reduces zebrafish mortality from influenza infection: Super-resolution microscopy reveals CPC interference with multiple protein interactions with phosphatidylinositol 4,5-bisphosphate in immune function

The COVID-19 pandemic raises significance for a potential influenza therapeutic compound, cetylpyridinium chloride (CPC), which has been extensively used in personal care products as a positively-charged quaternary ammonium antibacterial agent. CPC is currently in clinical trials to assess its effects on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) morbidity. Two published studies have provided mouse and human data indicating that CPC may alleviate influenza infection, and here we show that CPC (0.1 μM, 1 h) reduces zebrafish mortality and viral load following influenza infection. However, CPC mechanisms of action upon viral-host cell interaction are currently unknown. We have utilized super-resolution fluorescence photoactivation localization microscopy to probe the mode of CPC action. Reduction in density of influenza viral protein hemagglutinin (HA) clusters is known to reduce influenza infectivity: here, we show that CPC (at non-cytotoxic doses, 5-10 μM) reduces HA density and number of HA molecules per cluster within the plasma membrane of NIH-3T3 mouse fibroblasts. HA is known to colocalize with the negatively-charged mammalian lipid phosphatidylinositol 4,5-bisphosphate (PIP2); here, we show that nanoscale co-localization of HA with the PIP2-binding Pleckstrin homology (PH) reporter in the plasma membrane is diminished by CPC. CPC also dramatically displaces the PIP2-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) from the plasma membrane of rat RBL-2H3 mast cells; this disruption of PIP2 is correlated with inhibition of mast cell degranulation. Together, these findings offer a PIP2-focused mechanism underlying CPC disruption of influenza and suggest potential pharmacological use of this drug as an influenza therapeutic to reduce global deaths from viral disease.

Advances in the Prophylaxis of Respiratory Infections by the Nasal and the Oromucosal Route: Relevance to the Fight with the SARS-CoV-2 Pandemic

In this time of COVID-19 pandemic, the strategies for prevention of the infection are a primary concern. Looking more globally on the subject and acknowledging the high degree of misuse of protective face masks from the population, we focused this review on alternative pharmaceutical developments eligible for self-defense against respiratory infections. In particular, the attention herein is directed to the nasal and oromucosal formulations intended to boost the local immunity, neutralize or mechanically "trap" the pathogens at the site of entry (nose or mouth). The current work presents a critical review of the contemporary methods of immune- and chemoprophylaxis and their suitability and applicability in topical mucosal dosage forms for SARS-CoV-2 prophylaxis.

Influences of NaCl and Na2SO4 on the Micellization Behavior of the Mixture of Cetylpyridinium Chloride + Polyvinyl Pyrrolidone at Several Temperatures

Herein, the conductivity measurement technique is used to determine the interactions that may occur between polyvinyl pyrrolidone (PVP) polymer and cetylpyridinium chloride (CPC) surfactant in the presence of NaCl and Na2SO4 of fixed concentration at variable temperatures (298.15-323.15 K) with an interval of 5 K. In the absence or presence of salts, we observed three critical micelle concentrations (CMC) for the CPC + PVP mixture. In all situations, CMC1 values of CPC + PVP system were found to be higher in water than in attendance of salts (NaCl and Na2SO4). Temperature and additives have the tendency to affect counterion binding values. Various physico-chemical parameters were analyzed and demonstrated smoothly, including free energy (ΔG0m), enthalpy (ΔH0m) and entropy change (ΔS0m). The micellization process is achieved to be spontaneous based on the obtained negative ΔG0m values. The linearity of the ΔHmo and ΔSmo values is excellent. The intrinsic enthalpy gain (ΔH0*m) and compensation temperature (Tc) were calculated and discussed with logical points. Interactions of polymer hydrophobic chains or the polymer + surfactant associated with amphiphilic surface-active drugs can employ a strong impact on the behavior of the gels.

Localization-Based Super-Resolution Microscopy Reveals Relationship between SARS-CoV2 Spike and Phosphatidylinositol (4,5)-bisphosphate

Localization microscopy circumvents the diffraction limit by identifying and measuring the positions of numerous subsets of individual fluorescent molecules, ultimately producing an image whose resolution depends on the uncertainty and density of localization, and whose capabilities are compatible with imaging living specimens. Spectral resolution can be improved by incorporating a dichroic or dispersive element in the detection path of a localization microscope, which can be useful for separation of multiple probes imaged simultaneously and for detection of changes in emission spectra of fluorophores resulting from changes in their environment. These methodological advances enable new biological applications, which in turn motivate new questions and technical innovations. As examples, we present fixed-cell imaging of the spike protein SARS-CoV2 (S) and its interactions with host cell components. Results show a relationship between S and the lipid phosphatidylinositol (4,5)-bisphosphate (PIP2). These findings have ramifications for several existing models of plasma membrane organization.

Cationic Compounds with SARS-CoV-2 Antiviral Activity and Their Interaction with Organic Cation Transporter/Multidrug and Toxin Extruder Secretory Transporters

In the wake of the COVID-19 pandemic, drug repurposing has been highlighted for rapid introduction of therapeutics. Proposed drugs with activity against SARS-CoV-2 include compounds with positive charges at physiologic pH, making them potential targets for the organic cation secretory transporters of kidney and liver, i.e., the basolateral organic cation transporters, OCT1 and OCT2; and the apical multidrug and toxin extruders, MATE1 and MATE2-K. We selected several compounds proposed to have in vitro activity against SARS-CoV-2 (chloroquine, hydroxychloroquine, quinacrine, tilorone, pyronaridine, cetylpyridinium, and miramistin) to test their interaction with OCT and MATE transporters. We used Bayesian machine learning models to generate predictions for each molecule with each transporter and also experimentally determined IC50 values for each compound against labeled substrate transport into CHO cells that stably expressed OCT2, MATE1, or MATE2-K using three structurally distinct substrates (atenolol, metformin and 1-methyl-4-phenylpyridinium) to assess the impact of substrate structure on inhibitory efficacy. For the OCTs substrate identity influenced IC50 values, although the effect was larger and more systematic for OCT2. In contrast, inhibition of MATE1-mediated transport was largely insensitive to substrate identity. Unlike MATE1, inhibition of MATE2-K was influenced, albeit modestly, by substrate identity. Maximum unbound plasma concentration/IC50 ratios were used to identify potential clinical DDI recommendations; all the compounds interacted with the OCT/MATE secretory pathway, most with sufficient avidity to represent potential DDI issues for secretion of cationic drugs. This should be considered when proposing cationic agents as repurposed antivirals. SIGNIFICANCE STATEMENT: Drugs proposed as potential COVID-19 therapeutics based on in vitro activity data against SARS-CoV-2 include compounds with positive charges at physiological pH, making them potential interactors with the OCT/MATE renal secretory pathway. We tested seven such molecules as inhibitors of OCT1/2 and MATE1/2-K. All the compounds blocked transport activity regardless of substrate used to monitor activity. Suggesting that plasma concentrations achieved by normal clinical application of the test agents could be expected to influence the pharmacokinetics of selected cationic drugs.

Repurposing pharmaceutical excipients as an antiviral agent against SARS-CoV-2

The limited time indorsed to face the COVID-19 emergency and large number of deaths across the globe, poses an unrelenting challenge to find apt therapeutic approaches. However, lead candidate selection to phase III trials of new chemical entity is a time-consuming procedure, and not feasible in pandemic, such as the one we are facing. Drug repositioning, an exploration of existing drug for new therapeutic use, could be an effective alternative as it allows fast-track estimation in phase II-III trials, or even forthright compassionate use. Although, drugs repurposed for COVID-19 pandemic are commercially available, yet the evaluation of their safety and efficacy is tiresome and painstaking. In absence of any specific treatment the easy alternatives such as over the counter products, phytotherapies and home remedies have been largely adopted for prophylaxis and therapy as well. In recent years, it has been demonstrated that several pharmaceutical excipients possess antiviral properties making them prospective candidates against SARS-CoV-2. This review highlights the mechanism of action of various antiviral excipients and their propensity to act against SARs-CoV2. Though, repurposing of pharmaceutical excipients against COVID-19 has the edge over therapeutic agents in terms of safety, cost and fast-track approval trial burdened, this hypothesis needs to be experimentally verified for COVID-19 patients.

Oral antiseptics against coronavirus: in-vitro and clinical evidence

Angiotensin converting enzyme 2 (ACE2) is the cellular receptor for SARS-CoV-2, so ACE2-expressing cells can act as target cells and are susceptible to infection. ACE2 receptors are highly expressed in the oral cavity, so this may be a potential high-risk route for SARS-CoV-2 infection. Furthermore, the virus can be detected in saliva, even before COVID-19 symptoms appear, with the consequent high risk of virus transmission in asymptomatic/presymptomatic patients. Reducing oral viral load could lead to a lower risk of transmission via salivary droplets or aerosols and therefore contribute to the control of the pandemic. Our aim was to evaluate the available evidence testing the in-vitro and in-vivo effects of oral antiseptics to inactivate or eradicate coronaviruses. The criteria used were those described in the PRISMA declaration for performing systematic reviews. An electronic search was conducted in Medline (via PubMed) and in Web of Sciences, using the MeSH terms: ‘mouthwash’ OR ‘oral rinse’ OR ‘mouth rinse’ OR ‘povidone iodine’ OR ‘hydrogen peroxide’ OR ‘cetylpyridinium chloride’ AND ‘COVID-19’ OR ‘SARS-CoV-2’ OR ‘coronavirus’ OR ‘SARS’ OR ‘MERS’. The initial search strategy identified 619 articles on two electronic databases. Seventeen articles were included assessing the virucidal efficacy of oral antiseptics against coronaviruses. In conclusion, there is sufficient in-vitro evidence to support the use of antiseptics to potentially reduce the viral load of SARS-CoV-2 and other coronaviruses. However, in-vivo evidence for most oral antiseptics is limited. Randomized clinical trials with a control group are needed to demonstrate its clinical efficacy.

Inactivation of SARS-CoV-2 through Treatment with the Mouth Rinsing Solutions ViruProX® and BacterX® Pro

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic effects daily dental work. Therefore, infection control measures are necessary to prevent infection of dental personnel during dental treatments. The use of a preprocedural mouth rinse with chlorhexidine (CHX), cetylpyridinium chloride (CPC), or hydrogen peroxide (H₂O₂) solution for 30–60 s may reduce the viral load and may protect the personnel in a dental practice. In the present study the virucidal effect of the mouth rinsing solutions ViruProX^® with 0.05% CPC and 1.5% H₂O₂ and BacterX^® pro containing 0.1% CHX, 0.05% CPC, and 0.005% sodium fluoride (F^-) was investigated in vitro. The mouth rinsing solutions successfully inactivated infectious SARS-CoV-2 particles, the causative agent of coronavirus disease 2019 (COVID-19), within 30 s. To determine the effective components, CHX, CPC, H₂O₂, and a combination of CHX and CPC, were tested against SARS-CoV-2 in addition. While a combination of CPC and CHX as well as CPC alone led to a significant reduction of infectious viral particles, H₂O₂ and CHX alone had no virucidal effect against SARS-CoV-2. It can be assumed that preprocedural rinsing of the mouth with ViruProX^® or BacterX^® pro will reduce the viral load in the oral cavity and could thus lower the transmission of SARS-CoV-2 in dental practice.

Topical Oral and Intranasal Antiviral Agents for Coronavirus Disease 2019 (COVID-19)

With the largest viral loads in both symptomatic and asymptomatic patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) present in the oral and nasal cavities, agents that act on these two areas have the potential for large therapeutic and prophylactic benefit. A literature review was conducted to elucidate the possible agents useful in treatment of SARS-CoV-2. These agents were evaluated for their current applications, adverse reactions, their current state of study, and any future considerations in their management of coronavirus disease 2019 (COVID-2019). Our review has found that, while there are many promising agents with proven efficacy in their in-vitro efficacy against SARS-CoV-2, more clinical trials and in-vivo studies, as well as safety trials, must be conducted before these agents can be effectively implemented.

Can preprocedural mouthrinses reduce SARS-CoV-2 load in dental aerosols?

Dental professionals work closely with patients and present an increased risk of person-to-person transmission of SARS-CoV-2. Moreover, the use of ultrasonic scalers, air-water syringes, and slow and high-speed handpieces, which are common in the dental office, generate spatter and aerosol. The use of preprocedural mouthrinses has been proposed to reduce the viral load in saliva and oropharyngeal tissues, thus decreasing viral load in dental aerosol. Although some mouthrinses demonstrates an antiviral effect, there is limited evidence about the clinical efficacy of any mouthrinse in the reduction of SARS-CoV-2 in the dental aerosol. We hypothesized that mouthrinses may reduce SARS-CoV-2 viral load in the oropharynx and its fluids reducing viral load in dental aerosol. The potential use of mouthrinses is discussed, along with proposal of in vitro and clinical studies, in order to evaluate this hypothesis. If this hypothesis holds true, dental professionals and patients may benefit from the routine use of preprocedural mouthrinses.

Efficacy of commercial mouth-rinses on SARS-CoV-2 viral load in saliva: randomized control trial in Singapore

Purpose

One of the key approaches to minimize the risk of COVID-19 transmission would be to reduce the titres of SARS-CoV-2 in the saliva of infected COVID-19 patients. This is particularly important in high-risk procedures like dental treatment. The present randomized control trial evaluated the efficacy of three commercial mouth-rinse viz. povidone–iodine (PI), chlorhexidine gluconate (CHX) and cetylpyridinium chloride (CPC), in reducing the salivary SARS-CoV-2 viral load in COVID-19 patients compared with water.

Methods

A total of 36 SARS-CoV-2-positive patients were recruited, of which 16 patients were randomly assigned to four groups—PI group (n = 4), CHX group (n = 6), CPC group (n = 4) and water as control group (n = 2). Saliva samples were collected from all patients at baseline and at 5 min, 3 h and 6 h post-application of mouth-rinses/water. The samples were subjected to SARS-CoV-2 RT-PCR analysis.

Results

Comparison of salivary Ct values of patients within each group of PI, CHX, CPC and water at 5 min, 3 h and 6 h time points did not show any significant differences. However, when the Ct value fold change of each of the mouth-rinse group patients were compared with the fold change of water group patients at the respective time points, a significant increase was observed in the CPC group patients at 5 min and 6 h and in the PI group patients at 6 h.

Conclusion

The effect of decreasing salivary load with CPC and PI mouth-rinsing was observed to be sustained at 6 h time point. Within the limitation of the current study, as number of the samples analyzed, the use of CPC and PI formulated that commercial mouth-rinses may be useful as a pre-procedural rinse to help reduce the transmission of COVID-19.

ISRCTN (ISRCTN95933274), 09/09/20, retrospectively registered

Use of mouthwashes against COVID-19 in dentistry

The proximity to the patient during dental care, high generation of aerosols, and the identification of SARS-CoV-2 in saliva have suggested the oral cavity as a potential reservoir for COVID-19 transmission. Mouthwashes are widely-used solutions due to their ability to reduce the number of microorganisms in the oral cavity. Although there is still no clinical evidence that they can prevent the transmission of SARS-CoV-2, preoperative antimicrobial mouth rinses with chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), povidone-iodine (PVP-I), and hydrogen peroxide (H₂O₂) have been recommended to reduce the number of microorganisms in aerosols and drops during oral procedures. This paper therefore aims to provide a comprehensive review of the current recommendations on the use of mouthwashes against the COVID-19 pandemic and to analyse the advantages and disadvantages of most conventional antiseptic mouthwashes used in dentistry.

Topical lignocaine anaesthesia for oropharyngeal sampling for COVID-19

OBJECTIVES

To ascertain if topical lignocaine application in oropharynx prior to swab sampling to test for COVID-19 improves a patient's comfort and to assess its effect on the swab sample taken to conduct the RT-PCR.

METHODS

Adult patients testing positive on the RT-PCR COVID-19 test were sampled again within 48 h after administering topical oropharyngeal anaesthesia. Patients were asked to rate their discomfort on a visual analog scale (VAS) for both sample A and B. A qualitative real-time RT-PCR for detection of SARS-CoV-2 RNA, was performed, and the cycle threshold value (Ct), used as a surrogate marker for the viral load, was measured for the sample taken without lignocaine (sample A) and the sample taken post-lignocaine application (sample B). The difference in Ct values of both the groups was checked for any statistical significance using paired t-test. Wilcoxon signed rank test was used on VAS scores to determine any significant decrease in discomfort.

RESULTS

Forty patients were included in the study. Twenty-nine patients (72.5%) reported the procedure to be more comfortable post-lignocaine application. Median (IQR) discomfort on VAS decreased from 7 (1) to 5 (2) after lignocaine use, which was statistically significant (p < 0.05). Mean Ct value for sample A was 17.21 ± 5.25 and for sample B was 18.44 ± 4.8 (p > 0.05), indicating a non-significant effect of lignocaine on SARS-CoV-2 concentration in the sample.

CONCLUSION

Topical lignocaine, while improving the comfort of the procedure of oropharyngeal sampling for patient did not alter the SARS-CoV-2 viral load that was detected in nasal and oropharyngeal samples taken together.

COVID-19: Perspectives for the management of dental care and education

The rapid and abrupt transmission pattern of the SARS-CoV-2 unleashed the current COVID-19 pandemic, as recognized by the World Health Organization in March 2020. Considering the high risk of transmission of the virus in dental environments and the specificities in clinical practice, COVID-19 posed immediate challenges for dental care and education. Due to the need to establish infection prevention and control guidance in dental health settings to enable a safe clinical practice, this review aims to list the challenges and perspectives in managing dental care in services and schools. This review employed materials collected from PubMed and the main guidelines and studies on the novel coronavirus to provide an overview of the clinical procedures and decisions made by health care personnel in dental offices and dental schools. We expect the COVID-19 scenario to promote significant changes in clinical practice and dental education; dentists should seek specific and particular regulations for dental practice established by their state or country. Biosafety checklists are strongly recommended for appointments at dental services and face-to-face activities in dental schools.

Nasal disinfection for the prevention and control of COVID-19: A scoping review on potential chemo-preventive agents

BACKGROUND

Neither pre-exposure nor post-exposure chemo-prophylaxis agents are currently available to prevent COVID-19. On the other hand, high loads of SARS-CoV-2 are shed from the nasal cavity before and after symptoms onset.

OBJECTIVE

To conduct a scoping review on the available evidence on tolerable nasal disinfectants with encouraging health outcomes against SARS-CoV-2, i.e., agents effective against at least two different viruses beyond SARS-CoV-2.

METHODS

Online databases were searched to identify papers published during 2010-2020. Publications were selected if they were relevant to the scoping review. The review was narrative, describing for each treatment the mechanism(s) of action, tolerability, in vitro and in vivo evidence of the effects against SARS-CoV-2 and whether the product had been marketed.

RESULTS

Eight treatments were scrutinized: hypothiocyanite, lactoferrin, N-chlorotaurine, interferon-alpha, povidone-iodine, quaternary ammonium compounds, alcohol-based nasal antiseptics and hydroxychloroquine. In vitro viricidal effect against SARS-CoV-2 was reported for ethanol, alcohol-based hand sanitizers and povidone-iodine. Inhibition of other coronaviruses was described for lactoferrin, ethanol, hydroxychloroquine and quaternary ammonium compound. No treatment has been tested against SARS-CoV-2 in randomized controlled clinical trials thus far. However, interferon-alpha, lactoferrin and hydroxychloroquine were tested in one-arm open label uncontrolled clinical trial. Oxidant activity (hypothiocyanite, N-chlorotaurine and povidone-iodine), enhancement of endocytic and lysosomal pH (quaternary ammonium compounds and hydroxychloroquine) and destruction of the viral capsid (quaternary ammonium compounds, alcohol-based nasal antiseptics) were the main mechanisms of action. Lactoferrin and interferon-alpha have subtle biological mechanisms. With the exception of N-chlorotaurine, all other products available on the market.

CONCLUSIONS

Effective and safe chemo-prophylactic drugs against SARS-CoV-2 do not exist yet but most eligible candidates are already in the market. Whilst the human nasal cavity is the port of entry for SARS-CoV-2, the mouth is involved as exit site through emission of respiratory droplets. The well-known hand-to-nose-to-hand cycle of contamination requires appropriate additional strategies for infection control. To narrow down the subsequent laboratory and clinical investigations, a case-control approach could be employed to compare the use of candidate drugs among individuals testing positive and negative to COVID-19 swabs.

Is the oral cavity relevant in SARS-CoV-2 pandemic?

Objectives

Recent scientific evidences suggest a relevant role of the oral cavity in the transmission and pathogenicity of SARS-CoV-2.

Methods

A literature search was performed in PubMed, up to April 30, 2020, focusing on SARS-CoV-2, COVID-19, oral cavity, and antimicrobial agents.

Results

Oral viral load of SARS-CoV-2 has been associated with the severity of COVID-19, and thus, a reduction in the oral viral load could be associated with a decrease in the severity of the condition. Similarly, a decrease in the oral viral load would diminish the amount of virus expelled and reduce the risk of transmission, since (i) during the first 10 days, the virus mainly accumulates at the nasal, oral, and pharyngeal area; (ii) the number of angiotensin-converting enzyme (ACE2) receptor is greater in the salivary glands as compared with the lungs; and (iii) salivary droplets represent the most relevant transmission route. To reduce the oral viral load, antiseptic agents may be used, although the evidence on its efficacy is indirect and weak.

Conclusions

Antiseptic mouth rinses, such as those containing cetylpyridinium chloride or povidone-iodine, may be able to decrease the severity of COVID-19 by reducing oral viral load in infected subjects and decreasing the risk of transmission by limiting viral load in droplets, generated in normal life, or in aerosols, produced during dental procedures. Well-designed clinical and preclinical research must be conducted to support these hypotheses.

Clinical relevance

Antiseptic mouth rinses may help in decreasing the severity of COVID-19 and in reducing the risk of transmission.

Recommendations for Dental Care during COVID-19 Pandemic

Dental clinics were suspected to be a hotspot for nosocomial transmission of coronavirus disease 19 (COVID-19), yet there has been no clear recommendation about emergency dental care and appropriate personal protective equipment during pandemics. In this paper, we aim to summarize recommendations for (i) patient risk assessment, (ii) patient triage, and (iii) measures to prevent infection of health professionals and nosocomial transmission in dental clinics. The available evidence was collected by performing searches on PubMed, Embase, and Cochrane databases. We reviewed papers on COVID-19, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), influenza, and related respiratory viral diseases. Legal and ethical frameworks, as well as international (e.g., World Health Organization (WHO)) and national (e.g., public health institutes, dental associations) guidelines were screened to summarize recommendations related to dental emergency care. To assess the patient risk, a questionnaire was developed to classify patients at unknown, high, and very high risk. Patient triage recommendations were summarized in a flow chart that graded the emergency level of treatments (i.e., urgent, as soon as possible, and postpone). Measures to prevent disease transmission based on current evidence were grouped for dental health professionals, dental clinics, and patients. The present recommendations may support health professionals implement preventative measures during the pandemic.

Repurposing Quaternary Ammonium Compounds as Potential Treatments for COVID-19

The COVID-19 pandemic has highlighted an important role for drug repurposing. Quaternary ammonium compounds such as ammonium chloride, cetylpyridinium and miramistin represent widely accessible antiseptic molecules with well-known broad-spectrum antiviral activities and represent a repurposing opportunity as therapeutics against SARS-CoV-2.

Better understanding of childhood asthma, towards primary prevention - are we there yet? Consideration of pertinent literature

Asthma is a chronic disease, characterized by reversible airway obstruction, airway inflammation and hyper-reactivity. The prevalence of asthma has risen dramatically over the past decade, affecting around 300,000,000 people. The etiology is multifactorial, with genetic, epigenetic, developmental and environmental factors playing a role. A complex interaction between the intrauterine environment, the developing immune system, the infant's microbiome and infectious organisms may lead to the development of allergic sensitization and asthma. Thus, a large number of studies have investigated the risk factors for childhood asthma, with a meticulous search of modifiable factors that could aid in primary prevention.

We present a current literature review from 2014-2017, as well as older classic publications, on the pathogenesis and the potential modifiable factors for primary prevention of asthma. No ideal preventive measure has yet been found. Rather, creating favorable prenatal and postnatal environments, minimal exposure to hostile environmental factors, prevention of infections in early life, allergic desensitization and nutritional modifications could possibly reduce asthma inception. In the era of personalized medicine, identifying individual risk factors and tailoring specific preventive measures is warranted.

Cetylpyridinium Chloride (CPC) Exhibits Potent, Rapid Activity Against Influenza Viruses in vitro and in vivo

Background:

There is a continued need for strategies to prevent influenza. While cetylpyridinium chloride (CPC), a broad-spectrum antimicrobial agent, has an extensive antimicrobial spectrum, its ability to affect respiratory viruses has not been studied in detail.

Objectives:

Here, we evaluate the ability of CPC to disrupt influenza viruses in vitro and in vivo.

Methods:

The virucidal activity of CPC was evaluated against susceptible and oseltamivir- resistant strains of influenza viruses. The effective virucidal concentration (EC) of CPC was determined using a hemagglutination assay and tissue culture infective dose assay. The effect of CPC on viral envelope morphology and ultrastructure was evaluated using transmission electron microscopy (TEM). The ability of influenza virus to develop resistance was evaluated after multiple passaging in sub-inhibitory concentrations of CPC. Finally, the efficacy of CPC in formulation to prevent and treat influenza infection was evaluated using the PR8 murine influenza model.

Results:

The virucidal effect of CPC occurred within 10 minutes, with mean EC₅₀ and EC_2log ranging between 5 to 20 μg/mL, for most strains of influenza tested regardless of type and resistance to oseltamivir. Examinations using TEM showed that CPC disrupted the integrity of the viral envelope and its morphology. Influenza viruses demonstrated no resistance to CPC despite prolonged exposure. Treated mice exhibited significantly increased survival and maintained body weight compared to untreated mice.

Conclusions:

The antimicrobial agent CPC possesses virucidal activity against susceptible and resistant strains of influenza virus by targeting and disrupting the viral envelope. Substantial virucidal activity is seen even at very low concentrations of CPC without development of resistance. Moreover, CPC in formulation reduces influenza-associated mortality and morbidity in vivo.