Encouraged by an evergrowing awareness concerning the faulty approach modern-day science cultivates toward medicine, we've begun searching for more efficient ways and methods of maintaining health. Seemingly unusual treatments the ancient cultures practiced became topics of conversation among the scientists who dare to think outside of the petrochemical box. One of such treatments originates from the Indian medical system (i.e. Ayurveda) which described silver as a potent therapeutic agent for many diseases. In this presentation, I'll take you through some of the scientifically proven health benefits of silver.
History
Silver found its application as a medical agent in 4000 b.c.e. Kings and aristocrats insisted on using silver vessels, not necessarily to denote wealth, but for the ability of silver to eliminate bacteria and preserve the freshness of water. The capability of silver to treat burns, ulcers, infected wounds, and various maladies was well known. Its use in different forms remained widespread until the advent of antibiotics after World War II. Nowadays, silver is being used as a component in various medical devices, such as post-operative incision dressings, blood and urinary catheters, endotracheal tubes, orthopedic devices, vascular prostheses, and the sewing ring of prosthetic heart valves. Silver is also commonly used as an alternative disinfectant in cases when traditional disinfectants such as chlorine may result in the formation of toxic by-products or cause corrosion of surfaces. Aside from medical applications, silver has also become a popular containment of dietary supplements.
Wonders Of Silver Ions
The efficacy of silver ions in inhibiting the growth and multiplication of microorganisms, including Escherichia coli and Staphylococcus aureus, has been proven by Korean scientists from the Laboratory of Toxicology, Seoul National University, and by Mr. James Collin's team, which found that silver, in the form of dissolved ions makes the bacteria cell more permeable and interferes with the cell's metabolism, leading to the overproduction of reactive and toxic oxygen compounds. Transmission electron microscopy showed significant changes in the bacterial cell membranes upon silver ion treatment. The study suggests that silver ions punch holes in bacterial membranes and wreak havoc when inside. They bind to essential cell components (e.g. DNA), thus, preventing the bacteria from performing even their most basic functions. Dead bacteria act like sponges, soaking up silver as they die, which turns them into "zombies" and causes them to wipe out their living compatriots. Silver ions cause Escherichia coli and Staphylococcus aureus bacteria to reach an active but nonculturable state and eventually die. This discovery led Collin's team to the conclusion that silver makes antibiotics up to a thousand times more effective against resistant bacteria. Mr. Vance Fowler, an infectious-disease physician at Duke University in Durham, North Carolina, says before adding silver to antibiotics, we must address toxicity very carefully to avoid causing argyria or harming the heart tissue.
Wonders Of Silver Nanoparticles
Nanotechnology has enabled us to apply pure silver in the size of nanoparticles, which are more efficient than silver ions. Technological breakthroughs opened new therapeutic horizons, and in the case of silver, the currently available data only reveals the surface of the potential benefits and the wide range of applications.
Effects of AgNP (silver nanoparticles) on HIV have been thoroughly examined. Experiments demonstrated the ability of silver nanoparticles to inhibit the transmission of HIV-1 infection in human cervix organ culture, as reported in 2010 by the Journal of Nanobiotechnology. The discovery has laid the ground for the development of new, potent antiviral drugs capable of preventing HIV infection and controlling virus replication.
Silver nanoparticles are attractive as antibacterial agents and virucidal agents because they are non-toxic to the human body at concentrations lower than 6 μg/mL, and have broad-spectrum antibacterial actions (just like silver ions, AgNPs also permeate cells and interfere with bacterial respiratory chain enzymes to inhibit energy production and growth). AgNPs increase the proliferation of lymphocytes and have a potent biocidal effect on at least 12 species of bacteria, including multi-resistant bacteria such as MRSA (Methicillin-resistant Staphylococcus aureus), multidrug-resistant Pseudomonas aeruginosa, ampicillin-resistant Escherichia coli, and erythromycin-resistant Streptococcus pyogenes.
Mr. Raymond Wai-Yin Sun's team reported that AgNPs were superior to gold nanoparticles for cytoprotective activities toward HIV-1-infected (Hut/CCR5) cells. Clinical and Laboratory Standards Institute reports that silver nanocubes also have higher antifungal properties than gold nanocubes, and other forms of silver nanoparticles, (e.g. nanospheres and nanowires).
Conclusion
Silver's oligodynamic (antimicrobial) action is indisputable, which makes it a helpful addition to the armamentarium against infection. Although high concentrations of silver interact with skin cells, the dosage required to alter cell respiration is 2500% greater than that needed to halt the growth of Pseudomonas aeruginosa. The molecular mechanisms of the action of silver against bacteria continue to be analyzed. So far, we have ascertained that silver is an effective bactericidal agent, and can be successfully used in the treatment of resistant bacteria.
Although rare, three known adverse side effects of overdosing with silver are argyria, temporary neurologic sequelae, and heart tissue damage. For that matter, further research is needed. Other than that, it is worth knowing that silver has been unsuccessful in some applications, such as the Silzone heart valve, while in applications such as orthopedic hardware, its benefit remains unproven.
Food for your thought: could it be true that silver coins and jewelry made of pure silver can inhibit the transmission of infections?
References
Nadia S.R., Enue E.S.R., Charles P.G., Kelly R.B. - Silver as a Disinfectant. Reviews of Environmental Contamination and Toxicology. 2007; 191: 23–45. doi: 10.1007/978-0-387-69163-3_2.
Jun S.K., Eunye K., Kyeong N.Y., Jong-Ho K., Sung J.P., Hu J.L., So H.K., Young K.P., Yong H.P., Cheol-Yong H., Yong-Kwon K., Yoon-Sik L., Dae H.J., Myung-Haing C. - Antimicrobial Effects of Silver Nanoparticles. Nanomedicine. 2007 Mar;3(1):95-101. doi: 10.1016/j.nano.2006.12.001.
Brian O., James C. - Silver Makes Antibiotics Thousands of Times More Effective. Science Translational Medicine. 2013.
Racheli B.K.W., Rami P., David A. - Antibacterial Activity of Silver-Killed Bacteria: The "Zombies" Effect. Scientific Reports volume 5, Article number: 9555 (2015).
Ali J., Farzaneh H.E.H., Fereydoun P., Seyedhossein H., Bahram K., Alireza M., Karim D., Najme S. - Silver and Gold Nanostructures: Antifungal Property of Different Shapes of These Nanostructures on Candida Species. Medical Mycology, Volume 52, Issue 1, January 2014, Pages 65–72.
Amani D.P., Kristin T.C., Laura H.R., Robert G.S. - Use of Silver in the Prevention and Treatment of Infections. Surg Infect (Larchmt). 2013 Feb; 14(1): 8–20. doi: 10.1089/sur.2011.097.
Humberto H.L., Elsa N.G.T., Liliana I.T., Dinesh K.S. - Silver Nanoparticles are Broad-Spectrum Bactericidal and Virucidal Compounds. J Nanobiotechnology. 2011; 9: 30. Published online 2011 Aug 3. doi: 10.1186/1477-3155-9-30.
Humberto H.L., Nilda V.A.N., Liliana I.T., Cristina R.P. - Mode of Antiviral Action of Silver Nanoparticles Against HIV-1. J Nanobiotechnology. 2010 Jan. 20;8:1. doi: 10.1186/1477-3155-8-1.
Humberto H.L., Liliana I.T., Elsa N.G.T., Cristina R.P. - PVP Coated Silver Nanoparticles Block the Transmission of Cell-Free and Cell-Associated HIV-1 in Human Cervical Culture. J Nanobiotechnology. 2010 Jul 13;8:15. doi: 10.1186/1477-3155-8-15.
Woo K.J., Hye C.K., Ki W.K., Sook S., So H.K., Yong H.P. - Antibacterial Activity and Mechanism of Action of the Silver Ion in Staphylococcus aureus and Escherichia coli. Appl Environ Microbiol. 2008 Apr; 74(7): 2171–2178. doi: 10.1128/AEM.02001-07
Jose R.M., Jose L.E., Alejandra C., Katherine H., Juan B.K., Jose T.R., Miguel J.Y. - The Bactericidal Effect of Silver Nanoparticles. Nanotechnology. 2005 Oct;16(10):2346-53. doi: 10.1088/0957-4484/16/10/059.
