Polyunsaturated fatty acids from Phyllocaulis boraceiensis mucus block the replication of influenza virus

Abstract

Influenza viruses cause worldwide outbreaks and pandemics in humans and animals every year with considerable morbidity and mortality. The molecular diversity of secondary metabolites extracted from mollusks is a good alternative for the discovery of novel bioactive compounds with unique structures and diverse biological activities. Phyllocaulis boraceiensis is a hermaphroditic slug that exudes mucus, in which was detected hydroxy polyunsaturated fatty acids that exhibited potent antiviral activity against measles virus. The objective of this study was to evaluate this property against Influenza viruses. Cell viability and toxicity of the mucus were evaluated on Madin-Darby canine kidney (MDCK) cells by MTT assay. Antiviral activity from mucus against influenza viruses was carried out by determination of the virus infection dose and by immunofluorescence assays. The crude mucus and its fractions exhibited low cytotoxicity on MDCK cells. A significant inhibition of viral replication, reduced by the order of eight times, was observed in influenza-induced cytopathic effect. In immunofluorescence assay was observed a decrease of more than 80% of the viral load on infected MDCK cell treated with mucus and its fractions. The viral glycoproteins hemagglutinin and neuraminidase located on the surface of the virus are crucial for the replications and infectivity of the influenza virus. Some authors demonstrated that lipids, such as, polyunsaturated fatty acids exhibited multiple roles in antiviral innate and adaptive responses, control of inflammation, and in the development of antiviral therapeutics. As corroborated by other studies, hydroxy polyunsaturated fatty acids interfered with the binding of influenza virus on host cell receptor and reduced viral titers. The results obtained indicated that polyunsaturated fatty acids from P. boraceiensis crude mucus and fractions 39 exerted antiviral activity against influenza virus.

Unsaturated Fatty Acids Control Biofilm Formation of Staphylococcus aureus and Other Gram-Positive Bacteria

“…Fatty acids are ubiquitous in nature and have shown many biological activities, such as antimicrobial [19], antifungal [20], antiviral [21], nematicidal [22] or anticancer activities [23]. Recently, linoleic acid has also been identified as essential for the sexual cycle of the pathogen Toxoplasma gondii in the feline gut [24] or the induction of a memory response of increased pathogenicity of Pseudomonas aeruginosa during its passage through the host [25].…”

Lipidomics and metabolomics signatures of SARS-CoV-2 mediators/receptors in peripheral leukocytes, jejunum and colon

“…Notably, 2-hydroxydecanoic acid has shown to inhibit the replication of varicella-zoster virus, poliovirus and HIV-1 [42] . Recently, hydroxy polyunsaturated fatty acids have also shown antiviral activity against measles influenza virus [43] . In line with this, we also found a strong association between the expression of ACE2 in peripheral leukocytes and the circulating levels of 19,20-dihydroxydocosapentaenoic acid.…”

Molluscan Compounds Provide Drug Leads for the Treatment and Prevention of Respiratory Disease

“…By comparison, biomedical research efforts have been focused in Europe (34%), North America (28%), and Asia (China and India, 27%). Only one South American species has been studied [153,154] and Australian species are also underrepresented (Table S1). Numerous sources attest to the importance of molluscs as traditional food sources as opposed to traditional medicines in Australia and throughout the Indo-pacific [155,156].…”

“…Preliminary antibacterial results from disc diffusion assays using some respiratory pathogens are presented by Cilia and Fratini [189], but statistically meaningful data are yet to be derived. de Toledo-Piza et al (2016) demonstrated impressive anti-viral activity with concentrated mucus from the terrestrial shell-less mollusc Phyllocaulis boraceiensis whereby host cell pre-treatment reduced Influenza A (H1N1) and measles virus-induced cytopathic effects by up to 80% with no host cell cytotoxicity [153,154]. Further studies should incorporate bioassay guided fractionation of concentrated mucus extracts to isolate and identify the active factors.…”