Hemin with Peroxidase Activity Can Inhibit the Oxidative Damage Induced by Ultraviolet A

Area of Science:

• Biochemistry
• Dermatology
• Oxidative Stress Research

Background:

• Ultraviolet A (UVA) radiation induces excessive reactive oxygen species (ROS), leading to significant oxidative damage in skin.
• Hemin is identified as a catalyst for the reaction between tyrosine (Tyr) and hydrogen peroxide (H2O2).

Purpose of the Study:

• To investigate the catalytic and ROS scavenging capabilities of hemin, particularly in combination with tyrosine.
• To evaluate the protective effects of the hemin-tyrosine mixture against oxidative damage in human skin keratinocyte (HaCaT) cells induced by H2O2 or UVA radiation.

Main Methods:

• Assessed hemin's catalytic reaction with tyrosine and hydrogen peroxide.
• Evaluated ROS scavenging activities using pyrogallol autoxidation, DPPH radical assays, and phenanthroline-Fe2+ assays.
• Quantified the protective effects on HaCaT cells by measuring apoptosis, cell death, lactate dehydrogenase (LDH) release, and malondialdehyde (MDA) accumulation.

Main Results:

• The hemin-tyrosine mixture demonstrated potent scavenging activity against H2O2, superoxide anion (O2-·), DPPH radical, and hydroxyl radical (·OH).
• Catalysis significantly reduced HaCaT cell apoptosis and death induced by H2O2 or UVA.
• The treatment inhibited LDH release and MDA accumulation, while enhancing cellular resistance to apoptosis.

Conclusions:

• The mixture of hemin and tyrosine exhibits significant protective effects against oxidative damage to HaCaT cells caused by UVA radiation.
• This combination shows promise as a protective agent for mitigating UVA-induced skin damage.