Anti-fish nodaviral activity of furan-2-yl acetate extracted from marine Streptomyces spp.

The antiviral activity of furan-2-yl acetate (C₆H₆O₃) extracted from Streptomyces VITSDK1 spp. was studied in cultured Sahul Indian Grouper Eye (SIGE) cells infected with fish nodavirus (FNV). The nodavirus infection in the SIGE cells was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) and the antiviral activity of furan-2-yl acetate was assessed by cytopathic effect, as well as reduction in nodaviral titre (TCID₅₀ mL⁻¹, where TCID₅₀) is the 50% tissue culture infective dose) in the cultured SIGE cells under in vitro conditions. Furan-2-yl acetate (20 µg mL⁻¹) effectively inhibited the replication of the FNV-infected SIGE cell lines and the viral titre was reduced from 4.3 to 2.45 log TCID₅₀ mL⁻¹ on treatments. Furan-2-yl acetate (20 µg mL⁻¹)- treated SIGE cell survival was found to be 90%, as determined by methyl thiazol tetrazolium assay. The results of an immunofluorescent assay revealed a strong association between the viral capsid protein inhibition and a decline in viral replication. The results suggest that furan-2-yl acetate suppressed FNV replication in cultured fish cells, providing a potential approach for the control of nodaviral diseases in marine fishes.