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Blue and Green Clays Show Medicinal Properties

Ancient people knew some clays have healing properties. They rubbed it on their skin to cover wounds. Now, U.S. researchers have discovered how the clays work and are researching their effectiveness against antibiotic resistant infections.

Blue and green clays are found in volcanic regions of the world, where native peoples used the clays to improve their health.

“There is evidence of Aboriginals using clays for treating wounds and they eat it. Many cultures eat clays to settle their stomach,” said Lynda Williams, a clay and mineral scientist at Arizona State University’s School of Earth and Space Exploration in Tempe.

Her team found the clay was effective against some pathogens that have evolved a resistance to other antibiotics.

In a paper published in the journal Nature Scientific Reports, Williams and colleagues describe how a blue-colored clay is effective against drug-resistant Staphylococcus aureus or MRSA, a potentially lethal skin infection, in the lab.

“We think it works differently from most antibiotics because it works on antibiotic-resistant strains of bacteria. So, we were just trying to figure out the mechanism that these natural clays, that have been used since the beginning of time, how they work,” she said.

The clay was also effective in treating Buruli ulcer, a flesh-eating skin disease in the African country of Ivory Coast.

Here's how it works: one of the clays’ ingredients is iron that bacteria need for respiration. Some of these same clays also contain aluminum.

But together, the minerals act as a sort of Trojan horse. The aluminum allows iron to flood into harmful bacteria and destroy it.

“In the end what we found is that aluminum is attacking the proteins in the cell wall of the bacterium and allowing pores to open so iron .. goes into the interior of the bacterium and has reactions with the protein inside. It becomes oxidized and it destroys the biomolecules inside the cell, killing the bacteria,” she said.

Williams hopes the research, funded by the National Science Foundation, will attract the interest of pharmaceutical companies eager to explore the healing properties of blue and green clays.