Chinese herb compound shows promise as treatment for Ebola: study

WASHINGTON - Tetrandrine, a compound common in Chinese traditional medicine, has been found effective in treating the deadly Ebola virus disease in mice, US and German researchers said Thursday.

This may be due to the drug's ability to block two channels needed by the virus to move within a cell and infect it completely, they reported in the US journal Science.

"We are very excited about the progress made in this study and the momentum it provides as scientists across the world vigorously search for effective vaccines and treatments against Ebola virus," lead author Robert Davey of Texas Biomedical Research Institute said in a statement.

Ebola virus begins its entry into a cell by first binding to several types of cell surface proteins. Then the virus is taken into the cell and follows an endosomal route, or membrane-bound route that transports the virus to various cell compartments to complete infection.

The new study identified two calcium channels in endosomes, called two pore channels (TPCs), that control the movement of the Ebola virus within the cells and found that these channels can be blocked therapeutically with several drugs currently used to treat high blood pressure.

Working with a group in Munich, Germany and Southwest Research Institute, Davey's team found Tetrandrine was the most potent blocker of TPCs in mice.

"Starting Tetrandrine treatment soon after infection significantly enhanced the survival of mice without any detectable side effects ... when the treatment was started one day after virus challenge, half the mice survived," their paper wrote. " These results indicate that Tetrandrine is highly effective against disease in mice."

An accompanying article published by Science warned the findings don't indicate that "a viable treatment is close at hand. "

Tetrandrine has not been tested in a macaque model, the "gold standard" for Ebola drug efficacy testing, and it's not approved for use in humans except in China, the article said, noting that the dose given to mice may be toxic when its equivalent is used in humans.

"Given the mode of action, it seems unlikely that Tetrandrine treatment would be superior to the most advanced Ebola post-exposure treatments," it wrote.

So far, there have been more than 9,400 deaths since the Ebola outbreak began last year in Liberia, Sierra Leone and Guinea. The virus causes hemorrhagic fever in humans and currently has no approved therapy or vaccine.