PRB Pharmaceuticals and Lee's Pharmaceuticals have announced that a recent study by Taiwan researchers from the National Health Research Institutes demonstrates TF2b and TF3, two components of v38 AMF-1, inhibit the 3C-like protease encoded by SARS-CoV. v38 AMF-1, a fraction of the flu medication VIRA 38, is best known for its ability to inhibit bird flu virus (H5N1) infections.
The study ("Inhibition of SARS-CoV 3C-like Protease Activity by Theaflavin-3,3'-digallate (TF3)") was published in the June edition of Evid Based Complement Alternat Med. "The 3C-like protease (3CLpro) is one of the most promising targets for anti-SARS-CoV drugs due to its crucial role in the viral life cycle," commented Dr. John T.-A. Hsu, the senior author of the study.
"We are obviously pleased with these findings as we have patents filed on TF2b and TF3 for a number of infectious diseases including SARS and bird flu," said Dr. Charles Hensley, Chairman and CEO of PRB Pharmaceuticals. "In a much earlier study, Dr. John Tam at the Chinese University of Hong Kong showed v38 AMF-1 (TF1, TF2a, TF2b, and TF3) to be effective at inhibiting SARS virus replication. Subsequently, v38 AMF-1 and its fractions were shown to completely block bird flu virus (H5N1) infections."
VIRA 38 was used by the Taiwan Presidential staff and doctors at Sungshan Hospital (SARS management facility) during the SARS outbreak of 2003. "We were in Hong Kong and Taipei for the duration of the SARS epidemic and were able to see the destructive power of uncontrollable viruses," added Hensley. "Once the bird flu outbreak enters the pandemic stage, it's going to make SARS look mild."
VIRA 38, PRB Pharmaceuticals' over-the-counter broad-spectrum anti-viral medication, is known for its effectiveness in treating and preventing influenza. VIRA 38 has recently been shown to contain compounds that inhibit the bird flu (H5N1) virus. Researchers at the Chinese University of Hong Kong have previously discovered these same compounds to be effective against a variety of pathogens including SARS-CoV, the virus responsible for causing severe acute respiratory syndrome.