In vitro antiviral activity of lactoferrin and ribavirin upon hantavirus
Murphy ME, Kariwa H, Mizutani T, Yoshimatsu K, Arikawa J, Takashima I.
Laboratory of Public Health, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Bovine lactoferrin (LF) and ribavirin (Rbv) were tested as antiviral agents against Seoul type hantavirus (SR-11 strain) in vitro.
Hantaviral foci number in Vero E6 cells infected with SR-11 was reduced with LF treatment by 5 days post infection to obtain a 50% effective dose (ED50) of 2500 microg/ml, while pretreatment with LF was highly efficacious having an ED50 of 39 microg/ml. Conversely, 1 h pretreatment with Rbv revealed no inhibition of viral focus formation but could significantly reduce the number of viral foci (ED50: 10 microg/ml) when used from the time of viral infection.
One hour pre-treatment of the cell monolayer with LF and subsequent addition of Rbv revealed a synergistic anti-hantaviral effect against SR-11, <20 FFU/ml as compared to 10(5) foci/ml in the control.
One hour treatment of SR-11 with LF prior to cell inoculation gave an ED50 of 312.5 microg/ml. Whereas, washing the LF-pretreated cell monolayer with PBS demonstrated minimal focus reduction, suggesting LF lightly adheres to cells.
These results indicate that LF has anti-hantaviral activity in vitro and inhibition of virus adsorption to cells which play an important role in revealing the anti-hantaviral activity of LF. This paper reports for the first time the anti-hantaviral effect of LF.
PMID: 11003470 [PubMed - indexed for MEDLINE]