Scientists Think They Can Use Black to Help Kill Brain-Eating Amoebas

In folklore and movies, is one of the best tools against terrifying monsters like vampires and werewolves. But a recent study seems to show that it could help defeat some real-life horrors, too. Silver nanoparticles loaded with common anti-seizure drugs may be able to safely and effectively treat brain-eating infections caused by amoebas, the study found.

Amoebas are incredibly flexible, single-celled protozoans, capable of creating finger-like protrusions from their body that let them crawl where they need to go. Typically, they are not the least bit interested in people, preferring to live in freshwater or soil, where they feed on bacteria.

But when certain species of amoeba end up in a person's central nervous system and brain- usually by being inhaled through the nose of contaminated water they can literally feast on the brain's tissues. This mind-appointing, coupled with the generalized inflammation of the immune system, eventually shuts down the brain, though not before experiencing severe headaches, a loss of smell and taste, hallucinations, and coma.

The most notorious of these infections (called primary amebic meningoencephalitis, or PAM) is caused by Naegleria fowleri, colorfully known as the brain-eating amoeba.

"These diseases are still considered rare but always result in the patient's demise," lead author Ayaz Anwar, a research fellow at Sunway University in Malaysia, told Gizmodo. "Unfortunately, there are no single drugs available to treat these infections."

Indeed, there were only 30 cases of PAM recorded in the US from 2007 to 2017, according to the Centers for Disease Control and Prevention, with just three known survivors. And while doctors have put some experimental drugs against these infections, with seemingly good results, there remains no official treatment.

Part of what makes treating the brain so badly that it can not reach the brain easily from the bloodstream, thanks to the blood-brain barrier. While these drugs are sometimes used to treat these infections, they often do not work. But some drugs can be broken down into the main nervous system, which is used to treat seizure or anxiety. And Anwar and his team theorized that the right drugs could be retooled to fight PAM.

The three anti-seizure drugs that are used to test out-diazepam (sold as Valium), phenobarbital, and phenytoin-are known to affect cell receptors found in both amoeba and humans. They say, "Anwar told Gizmodo, because of the metal's inherent antimicrobial properties" and ability to be tolerated by the body, target. Other studies of theirs had been shown that antifungal drugs, packaged onto silver nanoparticles, were able to be better off N. fowleri, adding support to their hunch.

The team doused petri dishes containing N. fowleri and another group of amoeba that can cause fatal brain infections, Acanthamoeba, with the drugs alone and in combination with the silver. And while they were able to kill themselves, their effectiveness was amplified by the use of the silver. In the experiments with human cells, the team also found that the drug combinations were largely alive (the Valium / silver combo, in particular, appeared to be entirely non-toxic to cells), while still expanding the infection from spreading further.

The findings, published in ACS Chemical Neuroscience, are early. But studying these drugs-which are already often used to the neurological symptoms of an infection-has its perks, Anwar says.

"The best thing about using FDA-approved, clinically available drugs is that they are known to be safe and easier to procure, so in my opinion these are already having a head start," he said.

Studying potential treatments for rare diseases and diseases PAM is certainly a challenge. And there's still a lot to figure out, including the best way to deliver a treatment to a patient. Since amoebas get your nose through the nose, Anwar speculates that using a nasal spray to get the drugs up there would work just as well. For now, the team next to these studies can work in actual living animals.

[ACS Chemical Neuroscience]