8/22/2023 0 Comments Iota carrageenan bulkVirions are transmitted from person to person by respiratory droplets, aerosols or indirectly via contaminated surfaces. In addition to the nasal epithelium, they infect also other parts of the respiratory tract, such as the pharyngeal mucosa. Respiratory viruses enter the body mainly via the nasopharyngeal cavity. Considering the time- and cost-consuming path for the development of new therapeutics, particularly of specific monoclonal antibodies, the evaluation of existing drugs as well as natural substances for their antiviral activity against SARS-CoV-2 represent a fast and promising alternative. Together, this highlights the unmet urgent need to develop prophylactically as well as safe therapeutic agents, which should be widely available and broadly acting against different viral strains of SARS-CoV-2. Furthermore, herd immunity might be difficult to achieve, as the vaccines do not confer sterile immunity. Moreover, in the light of currently spreading VOCs, the efficacy of current vaccines against mutated virus strains still needs to be evaluated conclusively. There are currently no specific antiviral treatment options apart from monoclonal antibodies for high-risk patients, which need to be administered at an early time point of infection. In the light of this ongoing trend, the development of broadly effective prophylactic and therapeutic countermeasures remains of the utmost importance. These VOCs were suggested to show higher transmissibility and infectivity, causing drastically rising numbers of COVID-19 cases worldwide. VOCs include SARS-CoV-2 Alpha (also referred to as B.1.1.7 ), SARS-CoV-2 Beta (also referred to as B.1.351 ), SARS-CoV-2 Gamma (also referred to as P.1 ), as well as SARS-CoV-2 Delta (also referred to as B.1.617.2 ). Recently, different SARS-CoV-2 variants, that harbor amongst other alterations mutations in the receptor-binding domain (RBD) of the spike glycoprotein, have emerged worldwide and are spreading rapidly. Upon binding, SARS-CoV-2 can enter the cell either via membrane fusion after cleavage of the spike glycoprotein by the protease ACE2 or via endocytosis facilitated by proteases, such as cathepsin L. Both viruses bind to human angiotensin-converting enzyme 2 receptor (hACE2) via their heavily glycosylated spike protein. SARS-CoV-2 belongs to the genus Betacoronaviruses and is closely related to SARS-CoV, which caused an outbreak of atypical pneumonia in 2002–2003. These “Variants of Concern” (VOC) are the result of viral evolution and have the potential to evade vaccine- or infection-induced antiviral immune responses. While vaccination campaigns are ongoing, the emergence and spread of SARS-CoV-2 variants is becoming a major threat to public health. 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.īy now, the COVID-19 pandemic caused by the emergence of the Severe Acute Respiratory Syndrome Coronavirus type-2 (SARS-CoV-2) has resulted in around 256 million global cases and 5.1 million global deaths. Iota-carrageenan exhibits antiviral activity with comparable IC 50 values against the SARS-CoV-2 Wuhan type and the VOCs. 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. 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. 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. Hence, the need of effective and viable prevention options to reduce viral transmission is of outmost importance. 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. 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. The COVID-19 pandemic continues to spread around the world and remains a major public health threat.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |