• Food Science and Biotechnology
• /
• v.17 no.5
• /
• pp.1074-1078
• /
• 2008

To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

• Journal of Microbiology
• /
• v.34 no.3
• /
• pp.263-263
• /
• 1996

Infection of fish cells with IHNV resulted in gradual increase in cytosolic free $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in CHSE, gradual decrease in $[Ca^{2+}]_i$ in FHM, and no significant change in RTG cells. The degree of $[Ca^{2+}]_i$ increase or decrease was dependent on the amount of infectious virus, and these $[Ca^{2+}]_i$ variations were maximal at 16 hours after virus infection (p. i.) in both cell lines. When the fish cells were infected with inactivated IHNV, evident variation in $[Ca^{2+}]_i$ was not observed. Thus, infectivity of IHNV appears to correlate with changes in $[Ca^{2+}]_i$ in virus-infected cells. These IHNV-induced $[Ca^{2+}]_i$ changes were partially blocked by cycloheximide, but not affected by cordycepin. It seems to be that virus-induced $Ca^{2+}$ variations were more related with protein synthesis than RNA synthesis. Various $Ca^{2+}$ related drugs were used in search for the mechanisms of the $[Ca^{2+}]_i$, changes following IHNV infection of CHSE cells. Decreasing extracellular $Ca^{2+}$ concentration or blocking $Ca^{2+}$ influx from extracellular media inhibited the IHNV-induced increase in $[Ca^{2+}]_i$, in CHSE cells. Similar results were obtained with intracellular $Ca^{2+}$ blockers. Thus it is suggested that both the extracellular and the intracellular $Ca^{2+}$ sources are important in IHNV-induced $[Ca^{2+}]_i$ increase in CHSE cells.