Antiviral activity of carrageenan on hepatitis A virus replication in cell culture

Abstract Sulphated polysaccharides such as iota-, lambda- and kappa-carrageenans showed a potent inhibitory effect on the replication of hepatitis A virus (HAV) in the human hepatoma cell line PLC/PRF/5. No cytotoxic effects were detected with concentrations of carrageenans up to 200 μg/ml. The selectivity indices of these substances, calculated as the ratio of the dose that reduced the number of viable cells to 50 % (CD 50 ) to the effective dose that inhibited 50 % of viral antigen expression (ED 50 ), were > 400 with iota-carrageenan, > 222 with lambda-carrageenan and > 10 with kappa-carrageenan. The selectivity index of ribavirin (reference substance) was only 5. The 3 types of carrageenans resulted in concentration-dependent reduction of HAV-antigen expression and HAV infectivity. Iota-and lambda-carrageenan emerged, from the present study, as promising candidates for chemotherapy of acute hepatitis A.