Antiviral effects of ascorbic and dehydroascorbic acids in vitro.

In the present study, ascorbic acid weakly inhibited the multiplication of viruses of three different families: herpes simplex virus type 1 (HSV-1), influenza virus type A and poliovirus type 1. Dehydroascorbic acid, an oxidized form of ascorbic acid and hence without reducing ability, showed much stronger antiviral activity than ascorbic acid, indicating that the antiviral activity of ascorbic acid is due to factors other than an antioxidant mechanism. Moreover, addition of 1 mM Fe3+, which oxidizes ascorbic acid to dehydroascorbic acid and also enhances the formation of hydroxyl radicals by ascorbic acid in the culture media, strongly enhanced the antiviral activity of ascorbic acid to a level significantly stronger than that of dehydroascorbic acid.

Butyroyl-arginine as a potent virus inactivation agent.

Virus inactivation is a critical step in the manufacturing of recombinant therapeutic proteins, in particular antibodies, using mammalian expression systems. We have shown in the previous paper that arginine is effective in inactivation of herpes simplex virus type 1 (HSV-1) and influenza virus at low temperature under mildly acidic pH, i.e.

Antiviral activities of coffee extracts in vitro.

Both hot water extracts of coffee grinds and instant coffee solutions inhibited the multiplication of herpes simplex virus type 1, a representative enveloped DNA virus, when they were added to the culture medium of the virus-infected cells at a dose of one fifth the concentration suitable for drinking. The antiherpetic activity was independent of the suppliers (companies) of the coffee grinds and of the locations where the coffee beans were produced. Further characterization revealed that there are two different mechanisms, by which the coffee extracts exert inhibitory activities on the virus infection; (1) a direct inactivation of the infectivity of virus particle (i.

Effect of caffeine on the multiplication of DNA and RNA viruses.

The present study examined the effect of caffeine on RNA and DNA viruses, revealing that it inhibits the multiplication of both. In the presence of caffeine, the progeny virus yield of both herpes simplex virus type 1 (HSV-1) and poliovirus decreased with increasing concentrations of the reagent, although HSV-1 was much more sensitive than poliovirus. The influenza virus was not affected by caffeine at the same concentrations.

Arginine facilitates inactivation of enveloped viruses.

Virus inactivation is a key step for the purification of pharmaceutical proteins derived from recombinant mammalian expression systems and conventionally done using low pH-treatment, which is often harmful to the proteins to be purified. This is particularly true for antibodies, because immunoglobulin proteins undergo conformational changes at acidic pH. We have been developing mild elution solvents using arginine for Protein-A chromatography to minimize the low pH-induced damages on the antibodies.

Antiviral effect of octyl gallate against influenza and other RNA viruses.

Octyl gallate inhibited the multiplication of several RNA viruses with widely different structure and replication strategies; i.e. vesicular stomatitis virus (VSV), influenza virus and poliovirus.

Antiviral effect of octyl gallate against DNA and RNA viruses.

The effects of gallic acid (3,4,5-trihydroxybenzoic acid) and its alkyl esters on virus growth and virion infectivity were examined. All the compounds tested showed an inhibitory effect on the growth of herpes simplex virus type 1 (HSV-1) in HEp-2 or Vero cells. The antiviral activity of gallic acid alkyl esters was enhanced by increasing the number of carbon in the alkyl moieties of the compounds, reaching maximum at a carbon number of 12 (lauryl gallate), but both cytocidal activity and cytopathic effect of the compounds were also significantly increased simultaneously.