Drug-Repositioning Approach for the Discovery of Anti-Influenza Virus Activity of Japanese Herbal (Kampo)‎ Medicines In Vitro: Potent High Activity of Daio-Kanzo-To

Abstract EN

Influenza virus infections are a serious public health concern throughout the world.

Emergence of viral resistance to the currently approved anti-influenza drugs warrants the development of new antiviral agents.

Japanese herbal medicines called Kampo are very commonly used as prescription medication in Japan, and Mao-to is known to be effective against influenza that is caused by oseltamivir-resistant viruses.

However, influenza-related death occurs mainly among the elderly, and for patients with hypertension and diabetes, Mao-to may cause these diseases to worsen.

Therefore, the exploration of more potent and safe Kampo medicines may be a good strategy for developing new influenza medicines.

Here cell-based screening of anti-influenza virus activity for 42 approved Kampo medicines was performed using the drug-repositioning approach.

As a result, four Kampo medicines were selected as potent anti-influenza agents against the A/WSN/33 strain.

It was found that Daio-kanzo-to [50% inhibitory concentration (IC50) = 10.5 μg/mL; 50% cytotoxic concentration (CC50) = 71.6 μg/mL; selective index = 6.8] is more effective than Mao-to.

Daio-kanzo-to and its constituent Japanese Pharmacopoeia (JP) Rhubarb were also effective against H3N2 and H1N1 subtypes of influenza viruses, including oseltamivir-insensitive-2009 pandemic clinical isolates.

These data suggest the potential application of Daio-kanzo-to for influenza treatment.