A new compound that blocks excess free iron in the mitochondria may offer dramatic protection against Ultraviolet A (UVA) radiation in sunlight, according to scientists at the University of Bath and King's College London.

Most sunscreens protect well against solar Ultraviolet B radiation but have limited effectiveness against UVA-induced damage, relying on the reflective properties of creams to defend against dangerous UVA rays.

Free iron concentration is particularly high within the cell’s mitochondria, however upon exposure to UVA in sunlight, excess free iron acts as a catalyst for the production of toxic reactive oxygen species (ROS), damaging DNA, fat and proteins thereby increasing the risk of cell death and cancer.

The new compound, called the 'mitoiron claw,' a custom-designed iron chelator that moves directly to mitochondria where it safely binds the excess free iron, preventing it from reacting upon exposure to UVA rays.

The researchers hope to see the mitoiron claw compound added to sunscreens and skin care products within 3-4 years.

Tests with human skin fibroblast cells exposed to UVA radiation equivalent to 140 min of uninterrupted sun exposure at sea level, showed cells treated with the mitoiron claw were completely protected against cell death. By contrast, untreated cells suffered significant cell death.

“For efficient protection against UVA-induced iron damage of skin strong chelators are needed, but until now these risked toxic effects caused by non-targeted iron starvation of cells,” says researcher Charareh Pourzand, PhD, a senior lecturer in the Department of Pharmacy and Pharmacology at the University of Bath. "Our mitochondria-targeted compound provides a solution to this problem and can address an unmet need in the skincare and sunscreen fields.”

Now the team plans further work to explore the potential of this new type of compound.

The research is published in the Journal of Investigative Dermatology.

CAPTION: Researchers with the UV lamp.