COVID-19 Research: American Led Study Shows That Nasal Sprays With Xylitol And Iota-Carrageenan Might Help Protect Against COVID-19
: A study led by researchers from University of Tennessee, Amcyte Pharmaceutical Inc, 3LogixBio Inc and researchers from Argentina have demonstrated the antiviral effects of three candidate nasal spray formulations against the SARS-CoV-2, the agent that causes the COVID-19 disease that were based using a seaweed extract called Iota-Carrageenan and also Xylitol an artificial sweetener.
The research findings were published on a preprint server and are currently being peer-reviewed. https://www.biorxiv.org/content/10.1101/2020.08.19.225854v1
In the study, it was found that iota-carrageenan, which is commonly used as a thickening agent in food products, successfully inhibited SARS-CoV-2 in cell cultures at a concentration as low as 6 µg/mL.
Dr Julio César Vega at Amcyte Pharma and colleagues at the University of Tennessee Health Science Center and Fundación Pablo Cassará, Argentina, say the results suggest that the clinical use of iota-carrageenan nasal spray may help to prevent and treat COVID-19.
In addition, a low concentration of a hardwood extract called xylitol, which is commonly used as a sugar substitute, also inhibited SARS-CoV-2 in vitro.
The study team says that xylitol, in combination with iota-carrageenan, may also be beneficial.
The researchers say the concentrations at which the compounds showed antiviral activity could easily be achieved with the application of nasal sprays that are already commercially available in a number of countries.
Dr Vega told Thailand Medical News, “Both iota-carrageenan and xylitol are safe for humans, being used in much larger amounts as food additive and sweetener, respectively, than those that may be used for nasal delivery. Both are included in nasal formulations already on the market for use in children and adults.”
To date, there are no effective preventive or treatment approaches, and there is an urgent need to provide easily accessible, affordable therapies that can stop transmission and serve as early treatments.
Numerous studies have shown that during the early stages of infection, the main sites of viral replication are the nasal cavity and the nasopharynx.
Dr Vega added, “Therefore, the use of antiviral nasal sprays would contribute to reducing nasal and nasopharyngeal viral load, thus slowing down the disease progression in the treated patient and the disease transmission to others in close contact with him or her.”
Significantly, Iota-carrageenan has already been shown to exhibit antiviral activity through its interaction with the viral surface, which prevents viral entry and captures viral particles released by infected cells.
Carrageenans are linear sulfated polysaccharides that are often extracted from red seaweeds. Carrageenans are commercially available in the form of kappa (κ), iota (ι) or lambda (λ). They have been used in the food and skincare industry for ages and their antiviral capacity has been descr
ibed decades ago and has been experimentally confirmed on herpes virus type 1 and 2, human papiloma virus, H1N1 influenza virus, dengue virus, rhinovirus, hepatitis A virus, enteroviruses, and coronaviruses. Iota-carrageenan inhibits several viruses based on its interaction with the surface of viral particles, thus preventing them from entering cells and trapping the viral particles released from the infected cells. https://www.hindawi.com/journals/bmri/2015/825203/
In addition, iota-carrageenan has already been formulated into a nasal spray and proved to be effective against the virus that causes the common cold. Iota-carrageenan is most active against common-cold coronavirus, inhibiting the infection up to 90 %. An iota-carrageenan spray reduced mortality by at least 50 % in mice infected with lethal doses of H1N1 influenza virus https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0126577
The compound xylitol has also been shown to exert various health benefits and is already used in the form of a nasal spray to treat rhinosinusitis and middle ear infection. In vitro studies have also demonstrated antiviral activity of xylitol against human respiratory syncytial virus. https://pubmed.ncbi.nlm.nih.gov/27040626/
It should be noted that both iota-carrageenan and xylitol are safe for use in humans and are already included in nasal formulations marketed for use in children and adults.
In the current study, the research team has demonstrated the efficacy of three candidate nasal spray formulations at reducing the viral loads of SARS-CoV-2 coronavirus in Vero cell cultures.
In the case of iota-carrageenan, three sample formulations were tested in a dose-dependent manner (ranging from 600 µg/mL to 0 µg/mL) and compared with formulations containing a placebo.
The study team found that iota-carrageenan concentrations 600 µg/mL, 60 µg/mL, and 6 µg/mL were all effective at inhibiting SARS-CoV-2 in samples 1 and 2.
Interestingly in sample three, which was the most effective at inhibiting the virus, antiviral activity was also observed at all concentrations. However, sample three also contained xylitol, suggesting that this compound, in combination with iota-carrageenan, may provide further benefits.
Dr Vega commented, “Xylitol at a concentration of 5 % m/V has proved to be viricidal on its own, and the association with iota-carrageenan may be beneficial, as well.”
The study team says this hypothesis would need to be thoroughly tested in clinical trials, which are currently underway.
According to the study team, “The data presented here are certainly encouraging in this direction.”
The researchers say they are now starting a number of multicenter randomized controlled trials to assess the effectiveness of iota-carrageenan nasal spray formulations in hospital staff caring for patients with COVID-19, in patients with COVID-19 and in other individuals who have close contact with these individuals.
Dr Vega said, “However, it must be stressed that this and other similar nasal sprays are on the market, and their safety profile is remarkable.”
In a latest development it has been also revealed that many South American countries are now also using this combo of iota-carrageenan and xylitol in nasal sprays as ‘adjuvant prophylactics’ against the SARS-CoV-2 despite no formal studies concluding it effectiveness yet. The public is warned against developing a sense of false security in using drugs or therapeutics that do not have full and proper clinical studies to show its efficacy and also have yet to get any proper regulatory approvals.
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