An extract from the earthworm Eisenia fetida non-specifically inhibits the activity of influenza and adenoviruses

Abstract

ObjectiveTo test the in vitro antiviral activity of a crude tissue extract (CTE) from the earthworm Eisenia fetida, determine any effective components in the CTE, andelucidatepossiblemechanismsofaction. MethodsA CTE was made by homogenizing earthworms, followed by treatment with ammonium sulfate, then thermal denaturation. Inhibition of virus-induced cytopathic effect (CPE) was used to assess antiviral activity. Chromatographic analysis was used to identify effective components in the CTE. ResultsThe CTE inhibited viral CPE at non-cytotoxic concentrations. Chromatography indicated that antiviral components corresponded to three active peaks indicative of proteases, nucleases and lysozymes. For adenoviruses, reduction in viral activity occurred for 100 μg/mL CTE. The reduction in adenoviral activity for four fractions was 100%, 91.8%, 86.9%, and 94.7%. For influenza viruses, reduction in viral activity of 100%, 86.6%, 69.1% and 88.3% was observed for 37 μg/mL CTE. In addition, three active fractions mixture had stronger antiviral activity (98.7% and 96.7%) than three fractions alone. Gel electrophoresis results indicated that nucleases from E. fetida could degrade the genome of influenza viruses and adenoviruses. ConclusionThe earthworm CTE displayed non-specific antiviral properties, possibly mediated by a combination of proteases, nucleases and lysozymes. Nucleases likely participate in the antiviral process, and degrade the genome of the virus thereby preventing further replication.