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.