A potential new weapon in the fight against COVID-19 has been found sitting in plain sight. Kakishibu, the astringent juice of certain types of young persimmons, has been used since ancient times in Japan for everything from dying cloth to treating burns and hangovers. Researchers at Nara Medical University have discovered that the tannin-laden liquid may also prove effective in stopping the coronavirus.
Professors Itō Toshihiro and Yano Hisakazu of NMU announced at a press conference on September 15 that the research team they lead was able to neutralize the coronavirus in samples of human saliva by adding high concentrations of persimmon tannins. In tests, researchers found that after 10 minutes, the concoction had reduced the virus to one ten thousandth of its original potency, rendering it nearly harmless.
The pair were quick to warn that the findings do not imply that people can ward off COVID-19 merely by eating persimmons and are planning more research to determine the exact mechanisms and amount of tannins needed to suppress the coronavirus inside the human mouth. However, they hope their research will lead to preventive medicines that can be incorporated into products like gum and lozenges