Efficacy and safety of iota-carrageenan nasal spray versus placebo in early treatment of the common cold in adults: the ICICC trial

Structure and properties of polysaccharides from tetrasporophytes of Mazzaella parksii

The structure and anti-SARS-CoV-2 activity of sulfated polysaccharides (Mzpt) obtained in high yield (60 %) from tetrasporophytes of Mazzaella parksii were studied. Stepwise fractionation with KCl showed that Mzpt consisted of eight (MzptF1-MzptF8) carrageenans fractions, differing in structure and molecular weight. The yield of non-gelling MzptF8 was 58.1 % of the original Mzpt. According to IR and NMR spectroscopies, gelling MzptF1 and MzptF2 were mainly kappa/iota/nu-carrageenans. MzptF7 included mainly lambda-carrageenan and in smaller quantities kappa-, iota-, mu- and nu-carrageenans. MzptF8 had a complex composition and included gamma-carrageenan, unsulfated carrageenan, probably, delta-carrageenan and also structural elements of xi-, psi- and omicron-carrageenans. According to atomic force microscopy data, MzptF8 involved several polymer chains associated with each other in a disordered structure, in contrast to MzptF2, which formed three-dimensional networks. Unlike ribavirin and remdesivir, Mzpt was not cytotoxic to Vero E6 cells at concentrations >2000 μg mL-1. Mzpt was shown to inhibit SARS-CoV-2 replication in a dose-dependent manner in CPE inhibition and RT-PCR assays. IC50 was 92.0 μg mL-1, SI - 22. At concentration 250 μg mL-1, Mzpt caused the highest reduction in viral RNA levels with an inhibition coefficient of 31.1 % and exhibited significant inhibition of the early stages of virus-cell interaction.

Over-the-counter carrageenan-based sprays may interfere with PCR testing of nasopharyngeal swabs to detect SARS-CoV-2

Carrageenan-containing nasal sprays, available over-the-counter (OTC), are often marketed as having anti-viral effects. Carrageenan belongs to the glycosaminoglycan family alongside heparin, and heparin is known to inhibit real-time quantitative polymerase chain reaction (RT-qPCR) in nasopharyngeal swabs used to detect SARS-CoV-2. As heparin and carrageenan share structural similarities, this work aimed to investigate the interferent effect of carrageenan on RT-qPCR for SARS-CoV-2 detection across 4 different diagnostic platforms. This work demonstrated that in the presence of carrageenan samples return inaccurate and invalid results on the Seegene STARlet, while qualitative accuracy was maintained on the Cepheid GeneXpert, Roche Cobas LIAT, and Hologic Panther Aptima. Evidence of carrageenan interference on SARS-CoV-2 testing was consistent across two OTC brands and research-grade reconstituted iota-carrageenan, with 80% of results returning invalid regardless of the carrageenan formulation added to the samples. Further, a preliminary in vivo interference study demonstrated an increased Ct value within 15 minutes of carrageenan dosage, with Ct values restored 60 minutes post-application. A direct comparison of carrageenan- and heparin-mediated PCR interference demonstrated that carrageenan PCR interference occurs to a lesser degree, but is not reversible by the addition of heparinase I. As carrageenan is available OTC, interference with PCR testing that causes an increase in false negative results could lead to accidental spread of disease and could therefore have significant public health impacts on community testing of respiratory infectious diseases via PCR.

Decongestant Effect of "Coldamaris Akut", a Carrageenan- and Sorbitol-Containing Nasal Spray in Seasonal Allergic Rhinitis

Purpose

This study aimed to develop a hyperosmolar, barrier-forming nasal spray based on carrageenan and sorbitol, and to demonstrate its decongestant effect in the context of allergic rhinitis (AR).

Methods

The efficacy of the nasal spray components was tested in vitro by barrier function, virus replication inhibition, and water absorption assays. The decongestant effectiveness was assessed in a randomized, controlled, crossover environmental chamber trial, where participants with a history of seasonal grass pollen AR were exposed to grass pollen allergens under controlled conditions. Forty-one adults were randomized to receive either carrageenan- and sorbitol-containing nasal spray (CS) or saline solution (SS). After 1 week, participants repeated the exposure with the treatment they had not received before. The primary efficacy endpoint was the mean change in nasal congestion symptom score (NCSS). Secondary efficacy endpoints were nasal airflow, nasal secretion, total nasal symptom score (TNSS), total ocular symptom score (TOSS) and total respiratory symptom score (TRSS).

Results

Preclinical assays demonstrated barrier-building, virus-blocking, and water-withdrawing properties of the CS components. In the clinical study, there was no significant difference in mean NCSS change from pre- to post-treatment between CS and SS. However, nasal airflow increased over time after treatment with CS, while it declined after SS, leading to a growing difference in airflow between CS and SS (p = 0.04 at 6:00 h). Mean nasal secretion over 2-6 h was reduced by ~25% after CS (p = 0.003) compared to pre-treatment, while it was reduced by only ~16% after SS (p = 0.137). No significant differences in TNSS, TOSS and TRSS were observed between CS and SS.

Conclusion

CS improves nasal airflow and reduces nasal secretion in adults with AR. We propose CS as a safe and effective adjuvant to baseline pharmacological treatments.

Trial Registration

NCT04532762.

Astodrimer sodium nasal spray forms a barrier to SARS-CoV-2 in vitro and preserves normal mucociliary function in human nasal epithelium

COVID-19 remains a severe condition for many including immunocompromised individuals. There remains a need for effective measures against this and other respiratory infections, which transmit via virus-laden droplets that reach the nasal or oral mucosae. Nasal sprays offer potential protection against viruses. Such formulations should preserve normal nasal mucociliary function. The antiviral barrier efficacy and effects on mucociliary function of astodrimer sodium nasal spray (AS-NS) were evaluated and compared with other available nasal sprays-low pH hydroxypropyl methylcellulose (HPMC-NS), iota-carrageenan (Carr-NS), nitric oxide (NO-NS), and povidone iodine (PI-NS). Assays simulated clinical conditions. Antiviral barrier function and cell viability were assessed in airway cell monolayers, while a model of fully differentiated human nasal epithelium (MucilAir™) was utilized to evaluate tissue integrity, cytotoxicity, cilia beating frequency, and mucociliary clearance. AS-NS reduced infectious virus in cell monolayers and demonstrated a benign cytotoxicity profile. In human nasal epithelium ex vivo, AS-NS had no impact on mucociliary function (cilia beating nor mucociliary clearance). Carr-NS, HPMC-NS, NO-NS and PI-NS demonstrated limited antiviral effects, while HPMC-NS caused inhibition of mucociliary function. Astodrimer sodium nasal spray demonstrates an acceptable nonclinical efficacy and safety profile as a barrier nasal spray against respiratory viral infection in the nasal cavity.

Comparative study of HIV-1 inhibition efficiency by carrageenans from red seaweeds family gigartinaceae, Tichocarpaceae and Phyllophoraceae

The efficiency of human immunodeficiency virus-1 (HIV-1) inhibition by sulfated polysaccharides isolated from the various families of red algae of the Far East Pacific coast were studied. The anti-HIV-1 activity of kappa and lambda-carrageenans from Chondrus armatus, original highly sulfated X-carrageenan with low content of 3,6-anhydrogalactose from Tichocarpus crinitus and i/κ-carrageenan with hybrid structure isolated from Ahnfeltiopsis flabelliformis was found. The antiviral action of these polysaccharides and its low-weight oligosaccharide was compared with commercial κ-carrageenan. Here we used the HIV-1-based lentiviral particles and evaluated that these carrageenans in non-toxic concentrations significantly suppress the transduction potential of lentiviral particles pseudotyped with different envelope proteins, targeting cells of neuronal or T-cell origin. The antiviral action of these carrageenans was confirmed using the chimeric replication competent Mo-MuLV (Moloney murine leukemia retrovirus) encoding marker eGFP protein. We found that X-carrageenans from T. crinitus and its low weight derivative and λ-carrageenan from C. armatus effectively suppress the infection caused by retrovirus. The obtained data suggest that the differences in the suppressive effect of carrageenans on the transduction efficiency of HIV-1 based lentiviral particles may be related to the structural features of the studied polysaccharides.

Exploring carrageenan: From seaweed to biomedicine-A comprehensive review

Biomaterials are pivotal in the realms of tissue engineering, regenerative medicine, and drug delivery and serve as fundamental building blocks. Within this dynamic landscape, polymeric biomaterials emerge as the frontrunners, offering unparalleled versatility across physical, chemical, and biological domains. Natural polymers, in particular, captivate attention for their inherent bioactivity. Among these, carrageenan (CRG), extracted from red seaweeds, stands out as a naturally occurring polysaccharide with immense potential in various biomedical applications. CRG boasts a unique array of properties, encompassing antiviral, antibacterial, immunomodulatory, antihyperlipidemic, antioxidant, and antitumor attributes, positioning it as an attractive choice for cutting-edge research in drug delivery, wound healing, and tissue regeneration. This comprehensive review encapsulates the multifaceted properties of CRG, shedding light on the chemical modifications that it undergoes. Additionally, it spotlights pioneering research that harnesses the potential of CRG to craft scaffolds and drug delivery systems, offering high efficacy in the realms of tissue repair and disease intervention. In essence, this review celebrates the remarkable versatility of CRG and its transformative role in advancing biomedical solutions.

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

Preventing upper respiratory tract infections with prophylactic nasal carrageenan: a feasibility study

Aim: To observe upper respiratory tract infection (URTI) symptoms, rhinovirus levels and compliance with daily carrageenan nasal spray. Methods: 102 adults were randomized to carrageenan or saline placebo three times daily for 8 weeks and URTI symptoms were recorded. A control group (n = 42) only recorded URTI symptoms. Participants collected nasal swabs when symptomatic. Results: Regular daily carrageenan prophylaxis resulted in consistent but nonsignificant reductions in URTI symptoms versus the placebo group. Saline placebo decreased and increased some cold symptoms compared with no treatment. Conclusion: Daily prophylactic administration of antiviral carrageenan may not significantly reduce URTI symptoms. Due to low compliance, use in a population with specific reasons to avoid URTIs may be more appropriate. Disease-specific outcomes may be more useful than symptom reporting.

Preparation, structures, and biological functions of rhamnan sulfate from green seaweed of the genus Monostroma: A review

Rhamnan sulfate, a rhamnose-rich sulfated polysaccharide, is present in the cell walls of green seaweed belonging to the genus Monostroma. This macromolecule demonstrates promising therapeutic properties, including anti-coagulant, thrombolytic, anti-viral, anti-obesity, and anti-inflammatory activities, which hold potential applications in food and medical industries. However, rhamnan sulfate has not garnered as much attention from researchers as other seaweed polysaccharides, including alginate, carrageenan, and fucoidan. This review discusses the extraction and purification techniques of rhamnan sulfate, delves into its chemical structures and related elucidation approaches, and provides an overview of its biological functions. Future research should focus on the structure-activity relationship of rhamnan sulfate and the industrial preparation of rhamnan sulfate with a specific homogeneous structure to facilitate its practical applications.

Nasal delivery as a strategy for the prevention and treatment of COVID-19

INTRODUCTION

The upper respiratory tract is a major route of infection for COVID-19 and other respiratory diseases. Thus, it appears logical to exploit the nose as administration site to prevent, fight, or minimize infectious spread and treat the disease. Numerous nasal products addressing these aspects have been considered and developed for COVID-19.

AREAS COVERED

This review gives a comprehensive overview of the different approaches involving nasal delivery, i.e., nasal vaccination, barrier products, and antiviral pharmacological treatments that have led to products on the market or under clinical evaluation, highlighting the peculiarities of the nose as application and absorption site and pointing at key aspects of nasal drug delivery.

EXPERT OPINION

From the analysis of nasal delivery strategies to prevent or fight COVID-19, it emerges that, especially for nasal immunization, formulations appear the same as originally designed for parenteral administration, leading to suboptimal results. On the other hand, mechanical barrier and antiviral products, designed to halt or treat the infection at early stage, have been proven effective but were rarely brought to the clinics. If supported by robust and targeted product development strategies, intranasal immunization and drug delivery can represent valid and sometimes superior alternatives to more conventional parenteral and oral medications.

Biological activity of algal derived carrageenan: A comprehensive review in light of human health and disease

Carrageenans are a family of natural linear sulfated polysaccharides derived from red seaweeds and used as a common food additive. Carrageenan's properties, impact on health, and aesthetic benefits have all been studied for a long time; however, the mechanisms are still unclear. In pharmaceutical aspects, carrageenan displayed potential antioxidant and immunomodulatory properties in both in vivo and in vitro action. It also contributes to potential disease-preventive activities through dynamic modulation of important intracellular signaling pathways, regulation of ROS buildup, and preservation of major cell survival and death processes which leads to potential drug development. Furthermore, the chemical synthesis of the current bioactive medicine with confirmational rearrangement may increase availability and bioactivity needs diligent examination. In this review, we give an up-to-date overview of recent research on Carrageenan with reference to health and therapeutic advantages. In addition, we have focused on structural conformation and its primary strategic deployment in disease prevention, as well as the mechanistic investigation of how it functions to combat various disease-preventive employed for future therapeutic interventions. This review may get new insights into the possible novel role of carrageenan and open up a novel disease-preventive mechanism and enhance human health.

Reduction of Viral Load in Patients with Acute Sore Throats: Results from an Observational Clinical Trial with Echinacea/Salvia Lozenges

BACKGROUND

Acute tonsillopharyngitis or sore throat is an initial sign of viral respiratory tract infection (RTI) and an optimal indicator for early antiviral and anti-inflammatory intervention. Both of these actions have been attributed to Echinacea purpurea and Salvia officinalis.

METHODS

74 patients (age 13-69 years) with acute sore throat symptoms (<48 h) were treated with five Echinacea/Salvia lozenges per day (4,000 mg Echinacea purpurea extract [Echinaforce®] and 1,893 mg Salvia officinalis extract [A. Vogel AG, Switzerland] daily) for 4 days. Symptom intensities were recorded in a diary and oropharyngeal swab samples collected for virus detection and quantification via RT-qPCR.

RESULTS

The treatment was exceptionally well tolerated, no complicated RTI developed, and no antibiotic treatment was required. A single lozenge reduced throat pain by 48% (p < 0.001) and tonsillopharyngitis symptoms by 34% (p < 0.001). Eighteen patients tested virus positive at inclusion. Viral loads in these patients was reduced by 62% (p < 0.03) after intake of a single lozenge and by 96% (p < 0.02) after 4 days of treatment compared to pre-treatment.

CONCLUSIONS

Echinacea/Salvia lozenges represent a valuable and safe option for the early treatment of acute sore throats capable to alleviate symptoms and contribute to reducing viral loads in the throat.

Hintergrund

Akute Tonsillopharyngitis oder Halsschmerzen/entzündungen sind ein erstes Anzeichen einer viralen Atemwegsinfektion (vAWI) und ein optimaler Indikator für eine frühzeitige antivirale und entzündungshemmende Intervention. Beide Wirkungen werden Echinacea purpurea und Salvia officinalis zugeschrieben.

Methoden

74 Patienten (Alter 13–69 Jahre) mit akuten Halsschmerzen/entzündungen (<48 h) wurden mit fünf Echinacea/Salvia-Lutschtabletten pro Tag (Tagesdosis: 4'000 mg Echinacea purpurea-Extrakt [Echinaforce®] und 1'893 mg Salvia officinalis Extrakt [A. Vogel AG, Schweiz]) behandelt für 4 Tage. Die Symptomintensität wurde in einem Tagebuch aufgezeichnet und Rachenabstrichproben wurden zum Virusnachweis und zur Quantifizierung mittels RT-qPCR entnommen.

Resultate

Die Behandlung wurde außergewöhnlich gut vertragen, es entwickelte sich keine komplizierten AWI und es waren keine Antibiotikabehandlungen erforderlich. Eine einzelne Lutschtablette reduzierte die akuten Halsschmerzen um 48% (p < 0,001) und die allgemeinen Tonsillopharyngitis Symptome um 34% (p < 0,001). Achtzehn Patienten wurden bei der Aufnahme viruspositiv getestet. Die Viruslast wurde bei diesen Patienten nach Einnahme einer einzigen Lutschtablette um 62% (p < 0,03), und nach 4-tägiger Behandlung um 96% (p < 0,02) reduziert im Vergleich zu vor der Behandlung.

Schlussfolgerungen

Echinacea/Salvia-Lutschtabletten stellen eine sichere Option für die frühzeitige Behandlung akuter Halsschmerzen/entzündungen dar, die Symptome lindern, und zur Verringerung der Viruslast im Hals beitragen können.

A study protocol for a double-blind randomised placebo-controlled trial evaluating the efficacy of carrageenan nasal and throat spray for COVID-19 prophylaxis—ICE-COVID

Introduction

At present, vaccines form the only mode of prophylaxis against COVID-19. The time needed to achieve mass global vaccination and the emergence of new variants warrants continued research into other COVID-19 prevention strategies. The severity of COVID-19 infection is thought to be associated with the initial viral load, and for infection to occur, viruses including SARS-CoV-2 must first penetrate the respiratory mucus and attach to the host cell surface receptors. Carrageenan, a sulphated polysaccharide extracted from red edible seaweed, has shown efficacy against a wide range of viruses in clinical trials through the prevention of viral entry into respiratory host cells. Carrageenan has also demonstrated in vitro activity against SARS-CoV-2.

Methods and analysis

A single-centre, randomised, double-blinded, placebo-controlled phase III trial was designed. Participants randomised in a 1:1 allocation to either the treatment arm, verum Coldamaris plus (1.2 mg iota-carrageenan (Carragelose®), 0.4 mg kappa-carrageenan, 0.5% sodium chloride and purified water), or placebo arm, Coldamaris sine (0.5% sodium chloride) spray applied daily to their nose and throat for 8 weeks, while completing a daily symptom tracker questionnaire for a total of 10 weeks.

Primary outcome

Acquisition of COVID-19 infection as confirmed by a positive PCR swab taken at symptom onset or seroconversion during the study. Secondary outcomes include symptom type, severity and duration, subsequent familial/household COVID-19 infection and infection with non-COVID-19 upper respiratory tract infections. A within-trial economic evaluation will be undertaken, with effects expressed as quality-adjusted life years.

Discussion

This is a single-centre, phase III, double-blind, randomised placebo-controlled clinical trial to assess whether carrageenan nasal and throat spray reduces the risk of development and severity of COVID-19. If proven effective, the self-administered prophylactic spray would have wider utility for key workers and the general population.

Trial registration

NCT04590365; ClinicalTrials.gov NCT04590365. Registered on 19 October 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06685-z.

Marine Bioactive Compounds Derived from Macroalgae as New Potential Players in Drug Delivery Systems: A Review

The marine algal ecosystem is characterized by a rich ecological biodiversity and can be considered as an unexploited resource for the discovery and isolation of novel bioactive compounds. In recent years, marine macroalgae have begun to be explored for their valuable composition in bioactive compounds and opportunity to obtain different nutraceuticals. In comparison with their terrestrial counterparts, Black Sea macroalgae are potentially good sources of bioactive compounds with specific and unique biological activities, insufficiently used. Macroalgae present in different marine environments contain several biologically active metabolites, including polysaccharides, oligosaccharides, polyunsaturated fatty acids, sterols, proteins polyphenols, carotenoids, vitamins, and minerals. As a result, they have received huge interest given their promising potentialities in supporting antitumoral, antimicrobial, anti-inflammatory, immunomodulatory, antiangiogenic, antidiabetic, and neuroprotective properties. An additional advantage of ulvans, fucoidans and carrageenans is the biocompatibility and limited or no toxicity. This therapeutic potential is a great natural treasure to be exploited for the development of novel drug delivery systems in both preventive and therapeutic approaches. This overview aims to provide an insight into current knowledge focused on specific bioactive compounds, which represent each class of macroalgae e.g., ulvans, fucoidans and carrageenans, respectively, as valuable potential players in the development of innovative drug delivery systems.

Macromolecular Viral Entry Inhibitors as Broad-Spectrum First-Line Antivirals with Activity against SARS-CoV-2

Inhibitors of viral cell entry based on poly(styrene sulfonate) and its core-shell nanoformulations based on gold nanoparticles are investigated against a panel of viruses, including clinical isolates of SARS-CoV-2. Macromolecular inhibitors are shown to exhibit the highly sought-after broad-spectrum antiviral activity, which covers most analyzed enveloped viruses and all of the variants of concern for SARS-CoV-2 tested. The inhibitory activity is quantified in vitro in appropriate cell culture models and for respiratory viral pathogens (respiratory syncytial virus and SARS-CoV-2) in mice. Results of this study comprise a significant step along the translational path of macromolecular inhibitors of virus cell entry, specifically against enveloped respiratory viruses.

Astodrimer sodium antiviral nasal spray for reducing respiratory infections is safe and well tolerated in a randomized controlled trial

Astodrimer sodium is a dendrimer molecule with antiviral and virucidal activity against SARS-CoV-2 and other respiratory viruses in vitro, and has previously been shown to be safe and well tolerated, and not systemically absorbed, when applied to the vaginal mucosa. To investigate its potential utility as a topical antiviral, astodrimer sodium has been reformulated for application to the nasal mucosa to help reduce viral load before or after exposure to respiratory infection. The current investigation assessed the safety, tolerability and absorption of astodrimer sodium 1% antiviral nasal spray. This was a single-centre, double-blinded, randomized, placebo-controlled, exploratory clinical investigation. Forty healthy volunteers aged 18 to 65 years with no clinically significant nasal cavity examination findings were randomized 3:1 to astodrimer sodium nasal spray (N = 30) or placebo (N = 10) at an Australian clinical trials facility. An initial cohort of participants (N = 12 astodrimer, N = 4 placebo) received a single application (one spray per nostril) to assess any acute effects, followed by a washout period, before self-administering the spray four times daily for 14 days to represent an intensive application schedule. Extent of absorption of astodrimer sodium via the nasal mucosa was also assessed in this cohort. A second cohort of participants (N = 18 astodrimer, N = 6 placebo) self-administered the spray four times daily for 14 days. The primary endpoint was safety, measured by frequency and severity of treatment emergent adverse events (TEAEs), including clinically significant nasal cavity examination findings, in the safety population (all participants randomized who administered any spray). Participants were randomized between 6 January 2021 and 29 March 2021. TEAEs occurred in 8/10 (80%) participants in the placebo arm and 19/30 (63.3%) participants in the astodrimer sodium arm; all were of mild intensity. TEAEs considered potentially related to study product occurred in 5/10 (50%) participants receiving placebo and 10/30 (33.3%) of participants receiving astodrimer sodium. No participants experienced serious AEs, or TEAEs leading to withdrawal from the study. No systemic absorption of astodrimer sodium via the nasal mucosa was detected. Astodrimer sodium nasal spray was well tolerated and is a promising innovation warranting further investigation for nasal administration to potentially reduce infection and spread of community acquired respiratory virus infections.

Trial Registration: ACTRN12620001371987, first registered 22-12-2020 (Australia New Zealand Clinical Trials Registry, https://anzctr.org.au/).

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.

COVID-19 Pandemic and Periodontal Practice: The Immunological, Clinical, and Economic Points of View

The recent global health problem, COVID-19, has had far-reaching impacts on lifestyles. Although many effective WHO-approved vaccines have been produced that have reduced the spread and severity of the disease, it appears to persist in humans for a long time and possibly forever as everyday it turns out to have new mutations. COVID-19 involves the lungs and other organs primarily through cytokine storms, which have been implicated in many other inflammatory disorders, including periodontal diseases. COVID-19 is in a close association with dental and periodontal practice from two respects: first, repeated mandatory lockdowns have reduced patient referrals to dentists and limited the dental and periodontal procedures to emergency treatments, whereas it is important to recognize the oral manifestations of COVID-19 as well as the influence of oral and periodontal disease on the severity of COVID-19. Second, dentistry is one of the high-risk professions in terms of close contact with unmasked individuals, necessitating redefining the principles of infection control. The pressures of the economic recession on patients as well as dentists add to the difficulty of resuming elective dental services. Therefore, this study is divided into two parts corresponding to what mentioned above: the first part examines the clinical and immunological associations between COVID-19 and periodontal and oral diseases, and the second part delineates the measures needed to control the disease transmission in dental clinics as well as the economic impact of the pandemic era on dental services.

Influence of the Structural Features of Carrageenans from Red Algae of the Far Eastern Seas on Their Antiviral Properties

The structural diversity and unique physicochemical properties of sulphated polysaccharides of red algae carrageenans (CRGs), to a great extent, determine the wide range of their antiviral properties. This work aimed to compare the antiviral activities of different structural types of CRGs: against herpes simplex virus type 1 (HSV-1) and enterovirus (ECHO-1). We found that CRGs significantly increased the resistance of Vero cells to virus infection (preventive effect), directly affected virus particles (virucidal effect), inhibited the attachment and penetration of virus to cells, and were more effective against HSV-1. CRG1 showed the highest virucidal effect on HSV-1 particles with a selective index (SI) of 100. CRG2 exhibited the highest antiviral activity by inhibiting HSV-1 and ECHO-1 plaque formation, with a SI of 110 and 59, respectively, when it was added before virus infection. CRG2 also significantly reduced the attachment of HSV-1 and ECHO-1 to cells compared to other CRGs. It was shown by molecular docking that tetrasaccharides—CRGs are able to bind with the HSV-1 surface glycoprotein, gD, to prevent virus–cell interactions. The revealed differences in the effect of CRGs on different stages of the lifecycle of the viruses are apparently related to the structural features of the investigated compounds.

Iota-Carrageenan Inhibits Replication of SARS-CoV-2 and the Respective Variants of Concern Alpha, Beta, Gamma and Delta

The COVID-19 pandemic continues to spread around the world and remains a major public health threat. Vaccine inefficiency, vaccination breakthroughs and lack of supply, especially in developing countries, as well as the fact that a non-negligible part of the population either refuse vaccination or cannot be vaccinated due to age, pre-existing illness or non-response to existing vaccines intensify this issue. This might also contribute to the emergence of new variants, being more efficiently transmitted, more virulent and more capable of escaping naturally acquired and vaccine-induced immunity. Hence, the need of effective and viable prevention options to reduce viral transmission is of outmost importance. In this study, we investigated the antiviral effect of iota-, lambda- and kappa-carrageenan, sulfated polysaccharides extracted from red seaweed, on SARS-CoV-2 Wuhan type and the spreading variants of concern (VOCs) Alpha, Beta, Gamma and Delta. Carrageenans as part of broadly used nasal and mouth sprays as well as lozenges have the potential of first line defense to inhibit the infection and transmission of SARS-CoV-2. Here, we demonstrate by using a SARS-CoV-2 spike pseudotyped lentivirus particles (SSPL) system and patient-isolated SARS-CoV-2 VOCs to infect transgenic A549ACE2/TMPRSS2 and Calu-3 human lung cells that all three carrageenan types exert antiviral activity. Iota-carrageenan exhibits antiviral activity with comparable IC₅₀ values against the SARS-CoV-2 Wuhan type and the VOCs. Altogether, these results indicate that iota-carrageenan might be effective for prophylaxis and treatment of SARS-CoV-2 infections independent of the present and potentially future variants.

Management of acute upper respiratory tract infection: the role of early intervention

INTRODUCTION

Upper respiratory tract infection (URTI) is an illness caused by an acute infection by viruses or bacteria of the nose, sinuses, pharynx, and larynx. Most URTIs are short, mild, and self-limiting, but some can lead to serious complications, resulting in heavy social and economic burden on individuals and society.

AREAS COVERED

This article presents the management guidelines and consensus established through the Delphi method during an expert roundtable conducted in November 2020 and results of a targeted literature review.

EXPERT OPINION

The current acute URTI management strategies aim toward symptom alleviation and prevention of URTI virus transmission. The effectiveness of these strategies is highly increased with early intervention, administered prior to the peaking of viral shedding. This reduces the chances of developing a full-blown acute URTI, decreases symptom severity, and reduces viral transmission. Mucoadhesive gel nasal sprays have shown promising results for early intervention of acute URTI. They act by creating a barrier that can trap virus particles, thereby preventing invasion of the mucosa by the virus. Additionally, they deliver broad spectrum activity that is effective against a wide variety of pathogens that cause acute URTI. Acute URTI warrants greater attention and proactive management in reducing its burden.

Efficacy of a Nasal Spray Containing Iota-Carrageenan in the Postexposure Prophylaxis of COVID-19 in Hospital Personnel Dedicated to Patients Care with COVID-19 Disease

BACKGROUND

Iota-Carrageenan (I-C) is a sulfate polysaccharide synthesized by red algae, with demonstrated antiviral activity and clinical efficacy as nasal spray in the treatment of common cold. In vitro, I-C inhibits SARS-CoV-2 infection in cell culture.

RESEARCH QUESTION

Can a nasal spray with Iota-Carrageenan be useful in the prophylaxis of COVID-19 in health care workers managing patients with COVID-19 disease?

STUDY DESIGN AND METHODS

This is a pilot pragmatic multicenter, randomized, double-blind, placebo-controlled study assessing the use of a nasal spray containing I-C in the prophylaxis of COVID-19 in hospital personnel dedicated to care of COVID-19 patients. Clinically healthy physicians, nurses, kinesiologists and other health care providers managing patients hospitalized for COVID-19 were assigned in a 1:1 ratio to receive four daily doses of I-C spray or placebo for 21 days. The primary end point was clinical COVID-19, as confirmed by reverse transcriptase polymerase chain reaction testing, over a period of 21 days. The trial is registered at ClinicalTrials.gov (NCT04521322).

RESULTS

A total of 394 individuals were randomly assigned to receive I-C or placebo. Both treatment groups had similar baseline characteristics. The incidence of COVID-19 differs significantly between subjects receiving the nasal spray with I-C (2 of 196 [1.0%]) and those receiving placebo (10 of 198 [5.0%]). Relative risk reduction: 79.8% (95% CI 5.3 to 95.4; p=0.03). Absolute risk reduction: 4% (95% CI 0.6 to 7.4).

INTERPRETATION

In this pilot study a nasal spray with I-C showed significant efficacy in preventing COVID-19 in health care workers managing patients with COVID-19 disease.

CLINICAL TRIALS REGISTRATION

NCT04521322.

The Saliva of Probands Sucking an Iota-Carrageenan Containing Lozenge Inhibits Viral Binding and Replication of the Most Predominant Common Cold Viruses and SARS-CoV-2

PURPOSE

The aim of this study was to investigate whether sucking of an iota-carrageenan containing lozenge releases sufficient iota-carrageenan into the saliva of healthy subjects to neutralize representatives of the most common respiratory virus families causing common cold and SARS-CoV-2.

PATIENTS AND METHODS

In this monocentric, open label, prospective clinical trial, 31 healthy subjects were included to suck a commercially available iota-carrageenan containing lozenge. Saliva samples from 27 subjects were used for ex vivo efficacy analysis. The study's primary objective was to assess if the mean iota-carrageenan concentration of the saliva samples exceeded 5 µg/mL, which is the concentration known to reduce replication of human rhinovirus (hRV) 1a and 8 by 90%. The iota-carrageenan concentration of the saliva samples was analyzed by UV-Vis spectroscopy. The antiviral effectiveness of the individual saliva samples was determined in vitro against a panel of respiratory viruses including hRV1a, hRV8, human coronavirus OC43, influenza virus A H1N1pdm09, coxsackievirus A10, parainfluenza virus 3 and SARS-CoV-2 using standard virological assays.

RESULTS

The mean iota-carrageenan concentration detected in the saliva exceeds the concentration needed to inhibit 90% of hRV1a and hRV8 replication by 134-fold (95% CI 116.3-160.8-fold; p < 0.001). Thus, the study met the primary endpoint. Furthermore, the iota-carrageenan saliva concentration was 60 to 30,351-fold higher than needed to reduce viral replication/binding of all tested viruses by at least 90% (p < 0.001). The effect was most pronounced in hCoV OC43; in case of SARS-CoV-2, the IC90 was exceeded by 121-fold (p < 0.001).

CONCLUSION

Sucking an iota-carrageenan containing lozenge releases sufficient iota-carrageenan to neutralize and inactivate the most abundant respiratory viruses as well as pandemic SARS-CoV-2. The lozenges are therefore an appropriate measure to reduce the viral load at the site of infection, hereby presumably limiting transmission within a population as well as translocation to the lower respiratory tract.

TRIAL REGISTRATION

NCT04533906.

Rhinovirus Inhibitors: Including a New Target, the Viral RNA

Rhinoviruses (RVs) are the main cause of recurrent infections with rather mild symptoms characteristic of the common cold. Nevertheless, RVs give rise to enormous numbers of absences from work and school and may become life-threatening in particular settings. Vaccination is jeopardised by the large number of serotypes eliciting only poorly cross-neutralising antibodies. Conversely, antivirals developed over the years failed FDA approval because of a low efficacy and/or side effects. RV species A, B, and C are now included in the fifteen species of the genus Enteroviruses based upon the high similarity of their genome sequences. As a result of their comparably low pathogenicity, RVs have become a handy model for other, more dangerous members of this genus, e.g., poliovirus and enterovirus 71. We provide a short overview of viral proteins that are considered potential drug targets and their corresponding drug candidates. We briefly mention more recently identified cellular enzymes whose inhibition impacts on RVs and comment novel approaches to interfere with infection via aggregation, virus trapping, or preventing viral access to the cell receptor. Finally, we devote a large part of this article to adding the viral RNA genome to the list of potential drug targets by dwelling on its structure, folding, and the still debated way of its exit from the capsid. Finally, we discuss the recent finding that G-quadruplex stabilising compounds impact on RNA egress possibly via obfuscating the unravelling of stable secondary structural elements.

Seaweed polysaccharides: Emerging extraction technologies, chemical modifications and bioactive properties

Nowadays, consumers are increasingly aware of the relationship between diet and health, showing a greater preference of products from natural origin. In the last decade, seaweeds have outlined as one of the natural sources with more potential to obtain bioactive carbohydrates. Numerous seaweed polysaccharides have aroused the interest of the scientific community, due to their biological activities and their high potential on biomedical, functional food and technological applications. To obtain polysaccharides from seaweeds, it is necessary to find methodologies that improve both yield and quality and that they are profitable. Nowadays, environmentally friendly extraction technologies are a viable alternative to conventional methods for obtaining these products, providing several advantages like reduced number of solvents, energy and time. On the other hand, chemical modification of their structure is a useful approach to improve their solubility and biological properties, and thus enhance the extent of their potential applications since some uses of polysaccharides are still limited. The present review aimed to compile current information about the most relevant seaweed polysaccharides, available extraction and modification methods, as well as a summary of their biological activities, to evaluate knowledge gaps and future trends for the industrial applications of these compounds.Key teaching pointsStructure and biological functions of main seaweed polysaccharides.Emerging extraction methods for sulfate polysaccharides.Chemical modification of seaweeds polysaccharides.Potential industrial applications of seaweed polysaccharides.Biological activities, knowledge gaps and future trends of seaweed polysaccharides.

Carrageenan nasal spray may double the rate of recovery from coronavirus and influenza virus infections: Re-analysis of randomized trial data

In this individual patient data meta-analysis we examined datasets of two randomized placebo-controlled trials which investigated the effect of nasal carrageenan separately on children and adults. In both trials, iota-carrageenan was administered nasally three times per day for 7 days for patients with the common cold and follow-up lasted for 21 days. We used Cox regression to estimate the effect of carrageenan on recovery rate. We also used quantile regression to calculate the effect of carrageenan on colds of differing lengths. Nasal carrageenan increased the recovery rate from all colds by 54% (95% CI 15%-105%; p = .003). The increase in recovery rate was 139% for coronavirus infections, 119% for influenza A infections, and 70% for rhinovirus infections. The mean duration of all colds in the placebo groups of the first four quintiles were 4.0, 6.8, 8.8, and 13.7 days, respectively. The fifth quintile contained patients with censored data. The 13.7-day colds were shortened by 3.8 days (28% reduction), and 8.8-day colds by 1.3 days (15% reduction). Carrageenan had no meaningful effect on shorter colds. In the placebo group, 21 patients had colds lasting over 20 days, compared with six patients in the carrageenan group, which corresponds to a 71% (p = .003) reduction in the risk of longer colds. Given that carrageenan has an effect on diverse virus groups, and effects at the clinical level on two old coronaviruses, it seems plausible that carrageenan may have an effect on COVID-19. Further research on nasal iota-carrageenan is warranted.

The antiviral activity of iota-, kappa-, and lambda-carrageenan against COVID-19: A critical review

Objective

There is no specific antiviral treatment available for coronavirus disease 2019 (COVID-19). Among the possible natural constituents is carrageenan, a polymer derived from marine algae that possesses a variety of antiviral properties. The purpose of this review was to summarize the evidence supporting carrageenan subtypes' antiviral activity against the emerging severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19.

Methods

PubMed/MEDLINE and Google Scholar searches were conducted for publications using the terms 'carrageenan', 'iota carrageenan', 'kappa carrageenan', lambda-carrageenan', 'coronavirus', 'common cold', 'rhinovirus', and 'SARS-CoV-2' search was also done in grey literature to increase our understanding. A search for the word "carrageenan" was also carried out. Most of the publications were discussed in narrative.

Results

Carrageenan has been shown to have potent antiviral activity against both coronaviruses (coronavirus NL63, SARS-CoV-2) and non-coronaviruses such as dengue virus, herpes simplex virus, cytomegalovirus, vaccinia virus, vesicular stomatitis virus, sindbis virus, human immunodeficiency virus, influenza virus, human papillomavirus, rabies virus, junin virus, tacaribe virus, African swine fever, bovine herpes virus, suid herpes virus, and rhinovirus. No in vivo study has been conducted using carrageenan as an anti-SARS-CoV-2 agent. The majority of the in vivo research was done on influenza, a respiratory virus that causes common cold together with coronavirus. Thus, various clinical trials were conducted to determine the transferability of these in vitro data to clinical effectiveness against SARS-CoV-2. When combined with oral ivermectin, nasally administered iota-carrageenan improved outcome in COVID-19 patients. It is still being tested in clinics for single-dose administration.

Conclusion

Though the carrageenan exhibited potent antiviral activity against SARS-CoV-2 and was used to treat COVID-19 under emergency protocol in conjunction with oral medications such as ivermectin, there is no solid evidence from clinical trials to support its efficacy. Thus, clinical trials are required to assess its efficacy for COVID-19 treatment prior to broad application.

Seaweed Sulfated Polysaccharides against Respiratory Viral Infections

Respiratory viral infections have been a leading cause of morbidity and mortality worldwide. Despite massive advancements in the virology field, no specific treatment exists for most respiratory viral infections. Approved therapies against respiratory viruses rely almost exclusively on synthetic drugs that have potential side effects, restricting their use. This review aims to present natural marine sulfated polysaccharides possessing promising antiviral activity against respiratory viruses that could be a safe alternative to synthetic broad-spectrum antiviral drugs. The antiviral properties of marine sulfated polysaccharides are presented according to their mechanism of action on different types and strains of respiratory viruses, and the potential limits of their use are discussed.

Carrageenan-containing over-the-counter nasal and oral sprays inhibit SARS-CoV-2 infection of airway epithelial cultures

Pharmaceutical interventions are urgently needed to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission. As SARS-CoV-2 infects and spreads via the nasopharyngeal airways, we analyzed the antiviral effect of selected nasal and oral sprays on virus infection in vitro. Two nose sprays showed virucidal activity but were cytotoxic precluding further analysis in cell culture. One nasal and one mouth spray suppressed SARS-CoV-2 infection of TMPRSS2-expressing Vero E6 cells and primary differentiated human airway epithelial cultures. The antiviral activity in both sprays could be attributed to polyanionic ι- and κ-carrageenans. Thus, application of carrageenan-containing nasal and mouth sprays may reduce the risk of acquiring SARS-CoV-2 infection and may limit viral spread, warranting further clinical evaluation.

Broad-Spectrum Antiviral Agents Based on Multivalent Inhibitors of Viral Infectivity

The ongoing pandemic of the coronavirus disease (Covid-19), caused by the spread of the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), highlights the need for broad-spectrum antiviral drugs. In this Essay, it is argued that such agents already exist and are readily available while highlighting the challenges that remain to translate them into the clinic. Multivalent inhibitors of viral infectivity based on polymers or supramolecular agents and nanoparticles are shown to be broadly acting against diverse pathogens in vitro as well as in vivo. Furthermore, uniquely, such agents can be virucidal. Polymers and nanoparticles are stable, do not require cold chain of transportation and storage, and can be obtained on large scale. Specifically, for the treatment of respiratory viruses and pulmonary diseases, these agents can be administered via inhalation/nebulization, as is currently investigated in clinical trials as a treatment against SARS CoV-2/Covid-19. It is believed that with due optimization and clinical validation, multivalent inhibitors of viral infectivity can claim their rightful position as broad-spectrum antiviral agents.

Iota-carrageenan neutralizes SARS-CoV-2 and inhibits viral replication in vitro

In the absence of a vaccine and other effective prophylactic or therapeutic countermeasures the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) remains a significant public health threat. Attachment and entry of coronaviruses including SARS-CoV-2 is mainly mediated by the spike glycoprotein. Here, we show that iota-carrageenan can inhibit the cell entry of the SARS-CoV-2 spike pseudotyped lentivirus in a dose dependent manner. SARS-CoV-2 spike pseudotyped lentivirus particles were efficiently neutralized with an IC₅₀ value of 2.6 μg/ml iota-carrageenan. Experiments with patient isolated wild type SARS-CoV-2 virus showed an inhibition of replication in a similar range. In vitro data on iota-carrageenan against various Rhino- and endemic Coronaviruses showed similar IC₅₀ values and translated readily into clinical effectiveness when a nasal spray containing iota-carrageenan demonstrated a reduction of severity and duration of symptoms of common cold caused by various respiratory viruses. Accordingly, our in vitro data on SARS-CoV-2 spike pseudotyped lentivirus and replication competent SARS-CoV-2 suggest that administration of iota-carrageenan may be an effective and safe prophylaxis or treatment for SARS-CoV-2 infections.

Application of marine natural products in drug research

New diseases are emerging as the environment changes, so drug manufacturers are always on the lookout for new resources to develop effective and safe drugs. In recent years, many bioactive substances have been produced in the marine environment, which represents an alternative resource for new drugs used to combat major diseases such as cancer or inflammation. Many marine-derived medicinal substances are in preclinical or early stage of clinical development, and some marine drugs have been put on the market, such as ET743 (Yondelis®). This review presents the sources, activities, mechanisms of action and syntheses of bioactive substances based on marine natural products in clinical trials and on the market, which is helpful to understand the progress of drug research by application of marine natural products.

Safety and efficacy of iota-carrageenan nasal spray in treatment and prevention of the common cold

The common cold is one of the most frequent viral infections in humans. Although benign, its symptoms result in economic burden and can lead to severe or even fatal complications in children, elderly and groups with comorbidities. The main purpose of the treatment is the relief of symptoms; however, the medication is often associated with adverse effects. Iota-carrageenan is a polysaccharide that reveals antiviral activity by binding to viruses, inhibiting its replications and, consequently, its viral propagation. This systematic review of the literature aims to compare the effectiveness of an iota-carrageenan nasal spray to placebo. This systematic review was conducted through research in Cochrane Database, PubMed, Science Direct, SpringerLink, Oxford Journals, Elsevier, ClinicalKey, Wiley Online Library, Embase databases, in order to collect randomized and controlled clinical trials. In total, the research provided four articles regarding clinical trials for comparing iota-carrageenan nasal spray with placebo. The results show it has potent antiviral activity compared to placebo and a favorable safety profile. Although further research is needed, the concept of a physical barrier capable of reducing viral penetration of epithelial cells in the nasal mucosa is appealing, and could lead to alternative approaches, with positive impact on global health.

Review of the use of nasal and oral antiseptics during a global pandemic

A review of nasal sprays and gargles with antiviral properties suggests that a number of commonly used antiseptics including povidone-iodine, Listerine®, iota-carrageenan and chlorhexidine should be studied in clinical trials to mitigate both the progression and transmission of SARS-CoV-2. Several of these antiseptics have demonstrated the ability to cut the viral load of SARS-CoV-2 by 3-4 log10 in 15-30 s in vitro. In addition, hypertonic saline targets viral replication by increasing hypochlorous acid inside the cell. A number of clinical trials are in process to study these interventions both for prevention of transmission, prophylaxis after exposure, and to diminish progression by reduction of viral load in the early stages of infection.

Marine-Derived Secondary Metabolites as Promising Epigenetic Bio-Compounds for Anticancer Therapy

Sessile organisms such as seaweeds, corals, and sponges continuously adapt to both abiotic and biotic components of the ecosystem. This extremely complex and dynamic process often results in different forms of competition to ensure the maintenance of an ecological niche suitable for survival. A high percentage of marine species have evolved to synthesize biologically active molecules, termed secondary metabolites, as a defense mechanism against the external environment. These natural products and their derivatives may play modulatory roles in the epigenome and in disease-associated epigenetic machinery. Epigenetic modifications also represent a form of adaptation to the environment and confer a competitive advantage to marine species by mediating the production of complex chemical molecules with potential clinical implications. Bioactive compounds are able to interfere with epigenetic targets by regulating key transcriptional factors involved in the hallmarks of cancer through orchestrated molecular mechanisms, which also establish signaling interactions of the tumor microenvironment crucial to cancer phenotypes. In this review, we discuss the current understanding of secondary metabolites derived from marine organisms and their synthetic derivatives as epigenetic modulators, highlighting advantages and limitations, as well as potential strategies to improve cancer treatment.

Progress in Modern Marine Biomaterials Research

The growing demand for new, sophisticated, multifunctional materials has brought natural structural composites into focus, since they underwent a substantial optimization during long evolutionary selection pressure and adaptation processes. Marine biological materials are the most important sources of both inspiration for biomimetics and of raw materials for practical applications in technology and biomedicine. The use of marine natural products as multifunctional biomaterials is currently undergoing a renaissance in the modern materials science. The diversity of marine biomaterials, their forms and fields of application are highlighted in this review. We will discuss the challenges, solutions, and future directions of modern marine biomaterialogy using a thorough analysis of scientific sources over the past ten years.

Carrageenan: Drug Delivery Systems and Other Biomedical Applications

Marine resources are today a renewable source of various compounds, such as polysaccharides, that are used in the pharmaceutical, medical, cosmetic, and food fields. In recent years, considerable attention has been focused on carrageenan-based biomaterials due to their multifunctional qualities, including biodegradability, biocompatibility, and non-toxicity, in addition to bioactive attributes, such as their antiviral, antibacterial, antihyperlipidemic, anticoagulant, antioxidant, antitumor, and immunomodulating properties. They have been applied in pharmaceutical formulations as both their bioactive and physicochemical properties make them suitable biomaterials for drug delivery, and recently for the development of tissue engineering. This article provides a review of recent research on the various types of carrageenan-based biomedical and pharmaceutical applications.

Use of antimicrobial mouthwashes (gargling) and nasal sprays by healthcare workers to protect them when treating patients with suspected or confirmed COVID-19 infection

BACKGROUND

COVID-19 infection poses a serious risk to patients and - due to its contagious nature - to those healthcare workers (HCWs) treating them. If the mouth and nose of HCWs are irrigated with antimicrobial solutions, this may help reduce the risk of active infection being passed from infected patients to HCWs through droplet transmission or direct contact. However, the use of such antimicrobial solutions may be associated with harms related to the toxicity of the solutions themselves, or alterations in the natural microbial flora of the mouth or nose. Understanding these possible side effects is particularly important when the HCWs are otherwise fit and well.

OBJECTIVES

To assess the benefits and harms of antimicrobial mouthwashes and nasal sprays used by healthcare workers (HCWs) to protect themselves when treating patients with suspected or confirmed COVID-19 infection.

SEARCH METHODS

Information Specialists from Cochrane ENT and Cochrane Oral Health searched the Central Register of Controlled Trials (CENTRAL 2020, Issue 6); Ovid MEDLINE; Ovid Embase and additional sources for published and unpublished trials. The date of the search was 1 June 2020.  SELECTION CRITERIA: This is a question that urgently requires evidence, however at the present time we did not anticipate finding many completed randomised controlled trials (RCTs). We therefore planned to include the following types of studies: RCTs; quasi-RCTs; non-randomised controlled trials; prospective cohort studies; retrospective cohort studies; cross-sectional studies; controlled before-and-after studies. We set no minimum duration for the studies.   We sought studies comparing any antimicrobial mouthwash and/or nasal spray (alone or in combination) at any concentration, delivered to HCWs, with or without the same intervention being given to the patients with COVID-19.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Our primary outcomes were: 1) incidence of symptomatic or test-positive COVID-19 infection in HCWs; 2) significant adverse event: anosmia (or disturbance in sense of smell). Our secondary outcomes were: 3) viral content of aerosol, when present (if intervention administered to patients); 4) other adverse events: changes in microbiome in oral cavity, nasal cavity, oro- or nasopharynx; 5) other adverse events: allergy, irritation/burning of nasal, oral or oropharyngeal mucosa (e.g. erosions, ulcers, bleeding), long-term staining of mucous membranes or teeth, accidental ingestion. We planned to use GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We found no completed studies to include in this review. We identified three ongoing studies (including two RCTs), which aim to enrol nearly 700 participants. The interventions included in these trials are povidone iodine, nitric oxide and GLS-1200 oral spray (the constituent of this spray is unclear and may not be antimicrobial in nature).   AUTHORS' CONCLUSIONS: We identified no studies for inclusion in this review. This is not surprising given the relatively recent emergence of COVID-19 infection. It is promising that the question posed in this review is being addressed by two RCTs and a non-randomised study. We are concerned that only one of the ongoing studies specifically states that it will evaluate adverse events and it is not clear if this will include changes in the sense of smell or to the oral and nasal microbiota, and any consequences thereof. Very few interventions have large and dramatic effect sizes. If a positive treatment effect is demonstrated when studies are available for inclusion in this review, it may not be large. In these circumstances in particular, where those receiving the intervention are otherwise fit and well, it may be a challenge to weigh up the benefits against the harms if the latter are of uncertain frequency and severity.

Antimicrobial mouthwashes (gargling) and nasal sprays to protect healthcare workers when undertaking aerosol-generating procedures (AGPs) on patients without suspected or confirmed COVID-19 infection

BACKGROUND

COVID-19 infection poses a serious risk to patients and - due to its contagious nature - to those healthcare workers (HCWs) treating them. The risks of transmission of infection are greater when a patient is undergoing an aerosol-generating procedure (AGP). Not all those with COVID-19 infection are symptomatic, or suspected of harbouring the infection. If a patient who is not known to have or suspected of having COVID-19 infection is to undergo an AGP, it would nonetheless be sensible to minimise the risk to those HCWs treating them. If the mouth and nose of an individual undergoing an AGP are irrigated with antimicrobial solutions, this may be a simple and safe method of reducing the risk of any covert infection being passed to HCWs through droplet transmission or direct contact. Alternatively, the use of antimicrobial solutions by the HCW may decrease the chance of them acquiring COVID-19 infection. However, the use of such antimicrobial solutions may be associated with harms related to the toxicity of the solutions themselves or alterations in the natural microbial flora of the mouth or nose.

OBJECTIVES

To assess the benefits and harms of antimicrobial mouthwashes and nasal sprays administered to HCWs and/or patients when undertaking AGPs on patients without suspected or confirmed COVID-19 infection.

SEARCH METHODS

Information Specialists from Cochrane ENT and Cochrane Oral Health searched the Central Register of Controlled Trials (CENTRAL 2020, Issue 6); Ovid MEDLINE; Ovid Embase and additional sources for published and unpublished trials. The date of the search was 1 June 2020.  SELECTION CRITERIA: This is a question that urgently requires evidence, however at the present time we did not anticipate finding many completed RCTs. We therefore planned to include the following types of studies: randomised controlled trials (RCTs); quasi-RCTs; non-randomised controlled trials; prospective cohort studies; retrospective cohort studies; cross-sectional studies; controlled before-and-after studies. We set no minimum duration for the studies.   We sought studies comparing any antimicrobial mouthwash and/or nasal spray (alone or in combination) at any concentration, delivered to the patient or HCW before and/or after an AGP.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Our primary outcomes were: 1) incidence of symptomatic or test-positive COVID-19 infection in HCWs or patients; 2) significant adverse event: anosmia (or disturbance in sense of smell). Our secondary outcomes were: 3) COVID-19 viral content of aerosol (when present); 4) change in COVID-19 viral load at site(s) of irrigation; 5) other adverse events: changes in microbiome in oral cavity, nasal cavity, oro- or nasopharynx; 6) other adverse events: allergy, irritation/burning of nasal, oral or oropharyngeal mucosa (e.g. erosions, ulcers, bleeding), long-term staining of mucous membranes or teeth, accidental ingestion. We planned to use GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We found no completed studies to include in this review.   AUTHORS' CONCLUSIONS: We identified no studies for inclusion in this review, nor any ongoing studies. The absence of completed studies is not surprising given the relatively recent emergence of COVID-19 infection. However, we are disappointed that this important clinical question is not being addressed by ongoing studies.

Antimicrobial mouthwashes (gargling) and nasal sprays administered to patients with suspected or confirmed COVID-19 infection to improve patient outcomes and to protect healthcare workers treating them

BACKGROUND

COVID-19 infection poses a serious risk to patients and - due to its contagious nature - to those healthcare workers (HCWs) treating them. If the mouth and nose of patients with infection are irrigated with antimicrobial solutions, this may help the patients by killing any coronavirus present at those sites. It may also reduce the risk of the active infection being passed to HCWs through droplet transmission or direct contact. However, the use of such antimicrobial solutions may be associated with harms related to the toxicity of the solutions themselves or alterations in the natural microbial flora of the mouth or nose.

OBJECTIVES

To assess the benefits and harms of antimicrobial mouthwashes and nasal sprays administered to patients with suspected or confirmed COVID-19 infection to both the patients and the HCWs caring for them.

SEARCH METHODS

Information Specialists from Cochrane ENT and Cochrane Oral Health searched the Central Register of Controlled Trials (CENTRAL 2020, Issue 6); Ovid MEDLINE; Ovid Embase and additional sources for published and unpublished trials. The date of the search was 1 June 2020.  SELECTION CRITERIA: This is a question that urgently requires evidence, however at the present time we did not anticipate finding many completed RCTs. We therefore planned to include the following types of studies: randomised controlled trials (RCTs); quasi-RCTs; non-randomised controlled trials; prospective cohort studies; retrospective cohort studies; cross-sectional studies; controlled before-and-after studies. We set no minimum duration for the studies.   We sought studies comparing antimicrobial mouthwash and/or nasal spray (alone or in combination) at any concentration, delivered with any frequency or dosage to suspected/confirmed COVID-19 patients.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Our primary outcomes were: 1) RECOVERY* (www.recoverytrial.net) outcomes in patients (mortality; hospitalisation status; use of ventilation; use of renal dialysis or haemofiltration); 2) incidence of symptomatic or test-positive COVID-19 infection in HCWs; 3) significant adverse event: anosmia (or disturbance in sense of smell). Our secondary outcomes were: 4) change in COVID-19 viral load in patients; 5) COVID-19 viral content of aerosol (when present); 6) other adverse events: changes in microbiome in oral cavity, nasal cavity, oro- or nasopharynx; 7) other adverse events: allergy, irritation/burning of nasal, oral or oropharyngeal mucosa (e.g. erosions, ulcers, bleeding), long-term staining of mucous membranes or teeth, accidental ingestion. We planned to use GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We found no completed studies to include in this review. We identified 16 ongoing studies (including 14 RCTs), which aim to enrol nearly 1250 participants. The interventions included in these trials are ArtemiC (artemisinin, curcumin, frankincense and vitamin C), Citrox (a bioflavonoid), cetylpyridinium chloride, chlorhexidine, chlorine dioxide, essential oils, hydrogen peroxide, hypertonic saline, Kerecis spray (omega 3 viruxide - containing neem oil and St John's wort), neem extract, nitric oxide releasing solution, povidone iodine and saline with baby shampoo.  AUTHORS' CONCLUSIONS: We identified no studies for inclusion in this review. This is not surprising given the relatively recent emergence of COVID-19 infection. It is promising that the question posed in this review is being addressed by a number of RCTs and other studies. We are concerned that few of the ongoing studies specifically state that they will evaluate adverse events such as changes in the sense of smell or to the oral and nasal microbiota, and any consequences thereof. Very few interventions have large and dramatic effect sizes. If a positive treatment effect is demonstrated when studies are available for inclusion in this review, it may not be large. In these circumstances in particular it may be a challenge to weigh up the benefits against the harms if the latter are of uncertain frequency and severity.

Carrageenans as Broad-Spectrum Microbicides: Current Status and Challenges

Different kinds of red algae are enriched with chemically diverse carbohydrates. In particular, a group of sulfated polysaccharides, which were isolated from the cell walls of red algae, gained a large amount of attention due to their broad-spectrum antimicrobial activities. Within that group, carrageenans (CGs) were expected to be the first clinically applicable microbicides that could prevent various viral infections due to their superior antiviral potency and desirable safety profiles in subclinical studies. However, their anticipated beneficial effects could not be validated in human studies. To assess the value of a second attempt at pharmacologically developing CGs as a new class of preventive microbicides, all preclinical and clinical development processes of CG-based microbicides need to be thoroughly re-evaluated. In this review, the in vitro toxicities; in vivo safety profiles; and in vitro, ex vivo, and in vivo antiviral activities of CGs are summarized according to the study volume of their target viruses, which include human immunodeficiency virus, herpesviruses, respiratory viruses, human papillomavirus, dengue virus, and other viruses along with a description of their antiviral modes of action and development of antiviral resistance. This evaluation of the strengths and weaknesses of CGs will help provide future research directions that may lead to the successful development of CG-based antimicrobial prophylactics.

Intranasal Antiviral Drug Delivery and Coronavirus Disease 2019 (COVID-19): A State of the Art Review

OBJECTIVE

To provide a state of the art review of intranasal antiviral drug delivery and to discuss current applications, adverse reactions, and future considerations in the management of coronavirus disease 2019 (COVID-19).

DATA SOURCES

PubMed, Embase, and Clinicaltrials.gov search engines.

REVIEW METHODS

A structured search of the current literature was performed of dates up to and including April 2020. Search terms were queried as related to topics of antiviral agents and intranasal applications. A series of video conferences was convened among experts in otolaryngology, infectious diseases, public health, pharmacology, and virology to review the literature and discuss relevant findings.

CONCLUSIONS

Intranasal drug delivery for antiviral agents has been studied for many years. Several agents have broad-spectrum antiviral activity, but they still require human safety and efficacy trials prior to implementation. Intranasal drug delivery has potential relevance for future clinical trials in the settings of disease spread prevention and treatment of SARS-CoV-2 and other viral diseases.

IMPLICATIONS FOR PRACTICE

Intranasal drug delivery represents an important area of research for COVID-19 and other viral diseases. The consideration of any potential adverse reactions is paramount.

Iota-Carrageenan as an Antiviral Treatment for the Common Cold

Introduction:

The common cold syndrome of acute upper respiratory tract viral infection is the most common disease among mankind and is an extremely common illness in children. There is a great need for a safe and effective antiviral treatment with minimal side effects. The challenge in developing a treatment is the numerous and varied respiratory viruses that cause this common illness and the need for a treatment with good tolerability and safety.

Explanation:

All respiratory viruses must reach the cell surface by passing through respiratory fluid and mucus, and this common feature may allow for the development of antivirals that capture viruses during this transit.

This article discusses how large polyanionic molecules such as iota-carrageenan may trap positively charged respiratory viruses. Iota-carrageenan is a large polysaccharide molecule which is neither absorbed from the respiratory tract nor metabolised. It, therefore, does not have any pharmacological properties. Iota-carrageenan nasal spray has been shown to reduce the titres of respiratory viruses and to reduce the severity of symptoms in placebo-controlled clinical trials, including children and adults. The results of four clinical trials are presented.

Conclusion:

Iota-carrageenan is a good candidate as a safe and effective non-specific antiviral treatment for common cold, and more research is justified on polyanionic molecules like carrageenans as antivirals.