Antiviral action of different molecules obtained from invertebrates against avian coronavirus

Abstract Incidences of emerging/re-emerging deadly viral infections have significantly affected human health. For this reason, the search for new products against these agents has become an urgent need. The bioprospecting for bioactive molecules obtained from invertebrates, or their products, sources of research for new antibiotics and antivirals. Honey and propolis obtained from bees and stingless bees demonstrated antimicrobials, anti-inflammatory, antitumor, healing proprieties and several other functions. However, bioactive have also been obtained from other invertebrates, such as caterpillars and spiders, as demonstrated by our group. In this study, we identified potent antiviral effect against avian coronavirus in propolis from Scaptotrigona aff postica, hemolymph of Lonomia obliqua and from mygalin, isolated from hemocytes of spider Acanthoscurria gomesiana. The antiviral focus reduction assay was carried to evaluate the efficacy of treatment by measuring its ability to inhibit viral replication in cultures of infected cells (TCID) treated with sources of three different invertebrates. The main objective was to evaluate if the compounds can contain the infection, reduce the viral load, preventing that new viral particle from leaving the infected cell to spread the infection. Propolis and crude hemolymph reduced avian coronavirus by an average of 256 x. Fraction purified of propolis and a synthetic peptide from hemolymph (transferrin), reduced the virus titer by an average 64-fold. Reduction of 8-fold was observed when 160 µM of crude mygalin was used. Virus reduction with 26 µM of synthetic mygalin was average of 16 times. The antiviral responses of the three substances were dose dependent. The virus titer reduction was 2 times more intense when the substances were added 1 h before cell infection with the virus.