Free iron and copper ions (Fe and Cu ions)

Free iron and copper ions are redox-active metal species that function as essential catalysts and cofactors in various biological processes, most notably melanogenesis and the generation of reactive oxygen species (ROS). Copper is a mandatory cofactor for tyrosinase, the primary enzyme responsible for converting L-tyrosine into melanin; without copper, the enzyme remains inactive (Solano, 2014). Free or labile iron contributes to skin damage by catalyzing the Fenton reaction, which converts hydrogen peroxide into highly reactive hydroxyl radicals, leading to lipid peroxidation and DNA damage (Kozlowski et al., 2014). In the context of dermatology, these ions are considered therapeutic targets for treating hyperpigmentation and photoaging. Drugs and cosmeceuticals, such as kojic acid and phytic acid, act by chelating these ions, thereby sequestering them from their biological roles in pigment production and oxidative stress (Sarkar et al., 2013). Managing the levels of these free ions is crucial for maintaining skin homeostasis and preventing conditions like melasma or post-inflammatory hyperpigmentation (Fisher et al., 2002). Therapeutic challenges include ensuring that chelators do not interfere with essential systemic metalloproteins or cause mineral deficiencies. Overall, targeting the labile metal pool provides a non-enzymatic approach to modulating skin pigmentation and protecting against UV-induced oxidative damage.

Other names

Labile iron poolLabile copper poolRedox-active metal ionsCatalytic metal ionsLabile metal ions

Chelation of free copper and iron ions to prevent their participation in tyrosinase activation and Fenton-mediated reactive oxygen species (ROS) generation.