Researchers have discovered that drugs containing female estrogen block infection with the Ebola virus, a deadly disease for which there is no cure. Scientists stumbled upon estrogen as a potential weapon against Ebola while looking to find new uses for old drugs.
Ebola hemorrhagic virus is named after a river in the Democratic Republic of Congo in Africa, the continent where the disease is endemic. The infection, discovered in 1976, is extremely deadly, with a mortality rate of up to 90 percent. And amid concerns that the highly lethal virus could be weaponized by bioterrorists, scientists have been looking for ways to prevent infection with Ebola.
Lisa Johansen, director of research programs at Zalicus, a biotechnology company located in Cambridge, Massachusetts, says she and researchers at the U.S. Army Medical Research Institute of Infectious Diseases in Maryland and at the University of Virginia in Charlottesville screened 2,000 existing drugs, looking for chemical compounds that were effective against Ebola.
Investigators discovered that a number of human-made drugs, including selective estrogen receptor modulators, or SERMS, blocked Ebola’s entry into cells in lab cultures and in mice.
But it wasn’t the estrogen drugs’ hormonal activity that thwarted the Ebola virus, preventing infection.
Rather, Johansen says it was the compound’s chemical structure, and the structure of a number of other drugs, that hindered the microorganism, something that surprised researchers.
“I think that’s one of the things that’s exciting…When we looked at our inhibitors, we found that a lot of them are entry inhibitors. And a lot of them have the structure even though the mechanism is for something completely unrelated,” Johansen said.
SERMS are so-called designer drugs designed to act like estrogen without negative side effects. For example, Tamoxifen is an older SERM used to treat breast cancer and the newer Reloxifen is approved for the prevention and treatment of the bone-weakening condition osteoporosis. But they have potentially serious side effects such as an increased risk of other types of cancer.
Johansen envisions using SERMS and other repurposed compounds in a number of situations to prevent infection and death.
“I think they could be used both by a civilian population where outbreaks are as well as potentially by the military if they were in an area where there was an outbreak and they went in to intercede, or if somebody used them for bio-warfare,” Johansen said.
An article on using estrogen drugs and other compounds to prevent Ebola virus infection is published in the journal Science Translational Medicine.