A cure for the dreaded Zika virus may soon be on the horizon after scientists identified existing drugs that show promise in killing the infection.
Researchers from Johns Hopkins University (JHU), Florida State University (FSU) and the National Institutes of Health (NIH) examined 6,000 existing compounds that have already been approved for human use or are in the late stage of their clinical trials.
The team's goal was to identify a drug capable of preventing the Zika virus from replicating itself and killing the brain cells of infected individuals.
Developing new drugs often takes years or even decades to finish, something that the researchers didn't have the time to wait for. This is why they decided to screen existing drugs for a potential Zika virus killer.
They were able to find what they were looking for in three compounds that are already available for therapeutic use.
Potential Zika Drugs
The first compound the team found was niclosamide, an FDA-approved drug typically used to treat worm infections in people for almost 50 years.
According to the researchers, the drug is capable of inhibiting the spread of various viruses in culture systems. This includes the Japanese encephalitis flavivirus, a relative of the Zika virus that is also transmitted through mosquito bites.
Niclosamide has been shown to prevent the replication of Zika virus in human brain stem cells during laboratory tests. It has also been tagged as a category B drug, which means that it doesn't produce any threat to animal fetuses.
Another drug known as emricasan has also been identified as a possible killer for the Zika virus. Designed to reduce liver fibrosis and other injury caused by hepatitis C, the compound is already in the second phase of its clinical trials.
"Emricasan was well tolerated in human trials, and there were no significant adverse events," the researchers said.
The researchers also tagged a drug known as PHA-690509 as a potential compound for Zika virus targeting. It was shown to be able to prevent the infection from replicating itself and killing nerve cells.
Despite these recent discoveries, the researchers pointed out that the effects of the three compounds were only shown during tests on laboratory dishes filled with cells. They have yet to determine whether the drugs would have the same effect on human subjects.
Niclosamide, for example, is known to work in the human gut but it is still unclear whether it would also be as effective if used on the brain.
The researchers believe that the three compounds would work best if used as a cocktail. This would allow them to target the Zika virus in different fronts, similar to how drug cocktails are used to treat the AIDS-causing human immunodeficiency virus (HIV).
The team said more studies are needed involving animal and human models in order to find out if the drug compounds are indeed capable of treating Zika infection. It could take scientists several more years to develop an effective cure for the virus.
Zika has been linked to a development of several birth defects in unborn children, including an abnormal growth of infants' heads called microcephaly. The infection can also cause people to suffer from a paralyzing disorder known as Guillain-Barré syndrome.
The virus has already caused widespread epidemics in Caribbean and Latin American countries and several infection cases in Florida and Southeast Asia.
Zika is primarily spread through the bites of infected mosquitoes, but it can also be transmitted through sexual intercourse.
There is no known cure or vaccine for the Zika virus as of the moment.
The findings of the multi-organizational study are featured in the journal Nature Medicine.
