Suppression of iron catalyzed free radical generation by iron tyrosinate protein models

Platelet protein damage by free radicals and glycationin vitro: The pathological consequences

Modification of platelet proteins by free radicals and glycation has been studied in the present work, as anin vitro model. The results of the two parameters, SDS-PAGE and carbonylation study are quite corroborative. We observed that the inducers like ferrous sulphate, ascorbate (mainly in supraphysiological concentration) and glucose attack the protein in a dose dependent manner, of which ferrous sulphate is most potent. Proteins from aged and degenerative conditions like malignancy and diabetes mellitus have suffered greater damage than normal adult and foetal proteins. The individual life expectancy in terms of biological versus chronological age may also be worked out from the individual stress level.

Iron chelators may help prevent photoaging

For years, cosmetic ingredients for anti-aging treatments have attracted consumers. Skin aging is accelerated by reactive oxygen species (ROS), generated by exposure to solar ultraviolet radiation (UVR), in a process known as photoaging. Because cutaneous iron catalyses ROS generation, it is thought to play a key role in photoaging. Iron is essential to almost all forms of life. However, excess iron is potentially toxic as its catalytic activity induces the generation of ROS. Iron-catalysed ROS generation is involved in numerous pathological conditions, including cutaneous damage. When skin is directly exposed to UVR, cutaneous intracellular catalytic iron levels increase because of the release of iron from iron-binding proteins such as ferritin. Consequently, the subsequent ROS generation may overwhelm cutaneous defense systems such as the cellular iron sequestration and ROS scavenging capacity. The harmful role of excess cutaneous iron implies that there may be a potential for topical iron chelator treatments. We now consider cutaneous photodamage skin photoaging as the result of iron-catalysed ROS generation and discuss preventative strategies based on iron chelators.

Reduction of ultraviolet light-induced oxidative stress by amino acid-based iron chelators

The generation of free radicals by ultraviolet (UV) light accelerates skin aging, which is known as photoaging. Cutaneous iron catalyzes the generation of free radicals. We designed novel antioxidants that suppressed the iron-catalyzed free radical generation and the ensuing UV-induced damage by mimicking the binding site of iron sequestering proteins. These antioxidants, N-(2-hydroxybenzyl)amino acids, were prepared by condensation of amino acids such as glycine and L-serine with salicylaldehyde and followed by catalytic reduction. The compounds formed a 2:1 complex to iron ion. These amino acid derivatives inhibited the iron-induced hydroxyl radical generation (the Fenton reaction). The compounds also suppressed UV-induced lipid peroxidation in murine dermal fibroblast homogenates. In addition, N-(2-hydroxybenzyl)-L-serine showed protective activity against UV-induced cytotoxicity in murine dermal fibroblasts. Desferrioxamine, a strong iron sequestering compound, was effective in inhibiting the Fenton reaction and the lipid peroxidation, but it was ineffective in protecting against UV-induced cytotoxicity. The results suggest that UV-induced oxidative stress can be reduced by these amino acid derivatives.