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Saturday, October 25, 2014

Colloidal Silver: Natural Treatment for Ebola?

In the News: Silver and Ebola

There is a tremendous buzz about silver and Ebola …
For example, a Google search for silver and Ebola turns up 25 million hits.   And the FDA sent a cease and desist letter to the makers of Nano Silver, demanding that they stop claiming their product cures Ebola.
Many people who are into alternative health are convinced that colloidal silver cures Ebola.  On the other hand, many mainstream people are positive it’s bunk.
Who’s right? What does the science show?

Can Silver Really Kill Germs?

Metal ions can kill germs through the “oligodynamic effect”. As Wikipedia notes:

The oligodynamic effect …  was discovered in 1893 by the Swiss Karl Wilhelm von Nägeli as a toxic effect of metal ions on living cells, algae, molds, spores, fungi, viruses, prokaryotic and eukaryotic microorganisms, even in relatively low concentrations. This antimicrobial effect is shown by ions of mercury, silver, copper, iron, lead, zinc, bismuth, gold, aluminium, and other metals.
WebMD notes:

Colloidal silver can kill certain germs by binding to and destroying proteins.
Science Daily writes:

Silver has been known to have antibacterial properties since ancient times.
Silver has been used for thousands of years to fight infection.  The father of modern medicine – Hippocrates – discussed the use of silver in wound care.
Before the introduction of modern antibiotics, colloidal silver was used as a germicide and disinfectant.  In the early 20th century, surgeons routinely used silver sutures to reduce the risk of infection, silver-containing eyedrops to treat ophthalmic problems, for various infections,and sometimes internally. During World War I, soldiers used silver leaf  to treat infected wounds.

Today, the World Health Organization includes colloidal silver as a disinfection method for providing safe drinking water in developing countries.
Many modern hospitals filter hot water through copper-silver filters to defeat staph infections and Legionnaires’ disease.
Silver is used to disinfect the drinking water in two space stations: the International Space Station and Russia’s Mir .
The Journal Nanomedicine published a study in 2010 – written by scientists from Harvard Medical School, MIT’s Department of Chemical Engineering, Harvard-MIT Center for Cancer Nanotechnology Excellence, the University of Waterloo’s Nanotechnology Engineering and Brigham and Women’s Hospital – showing:

Inorganic nanoparticles, such as gold and silver, have been shown to have anti-HIV activity in vitro
Inorganic nanoparticles such as silver have antiviral effects or improve antiviral effects of other molecules, as in the case of gold nanoparticles.
Scientists from the University of Texas at Austin, Hong Kong and elsewhere have shown the same thing.
Janice L Speshock and Saber M. Hussain – while at the U.S. Air Force Research Laboratory (Hussain is still there as senior scientist; Speshock is now a professor at Wayne State Medical school) – documented that nano silver can inhibit monkeypox virus and Tacaribe virus.
They note:

Silver nanoparticles possess many unique properties that make them attractive for use in biological applications. Recently they received attention when it was shown that 10 nm silver nanoparticles were bactericidal [i.e. they kill bacteria] ….
And they point out:

Silver-containing nanoparticles have previously demonstrated antimicrobial efficacy against bacteria and viral particles.
(“Efficacy” is the scientific term for “how well it works”.)
They’ve also shown that silver nanoparticles have some effect on  Ebola …
Specifically, Cathepsin B – a type of enzyme which breaks down proteins – is an  essential ingredient for Ebola infection, according to studies by two different teams of American scientists. (But see this.)
Speshock and Hussain explained in a 2010 study:

Cathepsin B activity decreases in a dose-dependent manner with [both silver and gold] nanoparticles …

But Is It SAFE?

While alternative health folks claim that colloidal silver is safe, Speshock and Hussain caution that little is known about the risks of reducing these normal Cathepsin B cell enzymes which have important functions for our health.
Indeed, Dr. Hussain participated in a study showing that silver nanoparticles can decrease body weight and locomotor activity in adult male rats.
A study published last year in Critical Reviews In Microbiology notes:

There is little understanding of [silver nanoparticles'] interactions with microorganisms.
A Chinese team of scientists notes in a 2014 study published in the International Journal of Nanomedicine:

There is a limited number of  well-controlled studies on the potential toxicities of nanosilver, though these studies tend to suggest that NSPs [nanosilver particles] can induce toxicity in living beings. It should be noted that in vitro conditions are drastically different from in vivo conditions; however, longer-term studies and assessment of NSP toxicity must be conducted so that NSP exposure does not exceed toxic levels.
(A study published recently in the journal Nanomedicine: Nanotechnology, Biology and Medicine found no significant adverse effects from colloidal silver.)
And even proponents of a daily colloidal silver supplement admit that it kills beneficial gut bacteria, as well as dangerous bugs. As such, even they say that you shouldn’t overdo it.

Putting It All Together: Colloidal Silver As a Treatment for Ebola?

The University of Michigan’s Risk Science Center notes:

Silver has been used as an antimicrobial agent for thousands of years – the Romans used to use silverware to reduce food and drink-borne infection.  More recently, nanoparticles of silver have been used in everything from food containers to socks in an attempt to imbue them with microbe-killing properties.

When used in the right way, the material certainly does exhibit antimicrobial properties. But there’s a massive jump from odor-resistant socks to curing Ebola patients.

The source of Dr. Laibow’s [the main person touting silver to prevent Ebola] optimism appears to be a 2009 presentation of research carried out by Janice Speshock and Saber Hussain at the US Air Force National Laboratory.  A Powerpoint of this presentation has been declassified, and is currently doing the rounds on the internet.
The presentation reports on research into the effectiveness of silver nanoparticles in rendering hemorrhagic fever viruses like Ebola ineffective.  The study was carried out using cell cultures, and a number of viruses and virus-like particles.  It seemed to indicate that when the silver nanoparticles penetrated into cells along with the virus in sufficient quantities, they were effective at preventing the virus from being active once the cell had been exposed.

While it is impossible to interpret research findings from Powerpoint slides alone, the data do suggest that there are some unusual interactions between silver nanoparticles and Ebola-like viruses, although there are no data indicating whether similar interactions are also seen with other nanoparticles.  More importantly, they do not indicate whether these same interactions would occur in an infected patient.  They also do not indicate the quantity of silver nanoparticles someone wold need to take to render Ebola ineffective, or whether the necessary dose to have an effect would cause medical complications.

This presentation builds on previously published research by Speshock and Hussain that looked at Monkey Pox virus plaque formation inhibition by nano silver.  Using cell cultures, the researchers found that nano silver and and silver ions were effective at reducing Monkey Pox Virus-induced plaques.  However, they also concluded
“The present study demonstrates the feasibility of implementing the use, and characterizing the efficacy, of silver-based nanoparticles against [Monkey Pox Virus] infection in vitro. However, for nanoparticles to be used in therapeutic or prophylactic treatment regimens, it is critical to understand the in vivo toxicity and potential for long-term sequelae [i.e. complications] associated with exposure to these compounds.”
In 2010 Speshock and Hussain published research on the interaction of silver nanoparticles with Tacaribe virus.  The research – published in the Journal of Nanobiotechnology – indicated that in cell cultures, the presence of silver nanoparticles increased the cell uptake of the virus, but also suppressed its activity once in cells. They concluded
“Due to the known toxicity of Ag- NPs [silver nanoparticles] in many human cell lines, and the short time limit of efficacy following infection, the Ag-NPs would likely make a more effective decontamination tool as opposed to an in vivo therapeutic agent. However, if the Ag-NPs do indeed facilitate the uptake of arenaviruses into the cell and inactivate the virus prior to cell entry, further studies should be performed to determine if Ag- NPs can prove to be an effective vaccine adjuvant.” ***
With significantly more research, silver nanoparticles may have some role to play in preventing or managing infections.

But the research does not support clinical applications at this stage.  Even if there was proof that silver nanoparticles are effective in humans in suppressing viral activity (and there is not), there are critical questions over dose and delivery.

To be effective, there would need to be systemic uptake of nano silver within the body at doses that are sufficient to inhibit the Ebola virus, but low enough to prevent unacceptable harm.  Currently, scientists have no ideas what an appropriate dose is.

Even if they did, it is not clear how the silver nanoparticles would be delivered.  Taking the material orally – as would be expected of colloidal silver dietary supplements – is unlikely to be effective as silver nanoparticles dissolve in gastric juices.  Nanoparticle uptake from the gut into the body is also very poor.  Inhaling silver nanoparticles is likewise unlikely to lead to significant nano-silver distribution through the body.  Which leaves direct injection of silver nanoparticles into the bloodstream – not an option to be undertaken lightly with an unproven and untested nanomaterial.
Similarly, Live Science reports:

There is some evidence that silver has antimicrobial properties, said Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center in Nashville, Tennessee.
But as far as taking it orally as medicine, “silver has been tried in various other circumstances against several different infections with very limited effect,” Schaffner told Live Science.

[Dr. Amesh Adalja, an infectious-disease specialist and a senior associate at the University of Pittsburgh Medical Center's Center for Health Security] noted that silver coatings on bed railings, catheters and endotracheal tubes can inhibit bacteria from colonizing those surfaces. Silver is also added to certain topical antibacterial creams, such burn creams, to prevent infection, he said.

But there’s no peer-reviewed evidence that silver could help a person infected with the Ebola virus, Adalja said. And if the drug were actually made of tiny silver nanoparticles, then the particles could potentially penetrate cells and “wreak some havoc there,” Adalja added.
The bottom line is that colloidal silver – like mannose-binding lectins – is a powerful substances which can kill many dangerous germs. But – like lectins – it can also cause health problems in the wrong dosage or form.
As such, I believe that more scientific research has to be conducted before we know whether colloidal silver is effective in the treatment of Ebola and – if so – what the safe and appropriate dosage is.
End notes: In an emergency – say, if one were directly exposed to Ebola – one would have to make his or her own decision about whether to gulp down colloidal silver as a desperate measure. 
I am not a healthcare professional, and this does not constitute medical advice.
Disclosures: None. I don’t work for – or have any investments or other financial interest in – any companies which sell colloidal silver or medicine.