Antioxidant Peptides: Properties and Cosmetic Applications

What Are Antioxidant Peptides?

Antioxidant peptides are short chains of amino acids that can help counteract oxidative stress by donating an electron or hydrogen atom to stabilise free radicals. They may also bind metal ions, such as copper, which can be involved in biological processes associated with inflammation and skin ageing.

Oxidative stress can result from factors including mitochondrial metabolism and UV radiation. The accumulation of reactive oxygen species (ROS) is associated with signalling pathways that can affect collagen synthesis and increase the activity of matrix metalloproteinases (MMPs).

Factors Affecting Antioxidant Activity

The antioxidant activity of a peptide depends on several structural characteristics, including:

• Molecular weight: smaller peptides generally have a greater ability to donate hydrogen or electrons.
• Hydrophobicity: greater hydrophobicity may improve interaction with hydrophobic cellular structures such as biological membranes.
• Amino acid sequence: the specific amino acids and their arrangement influence antioxidant activity.

Hydrolyzed Collagen Peptides

Hydrolyzed collagen, also known as collagen hydrolysate, is produced by enzymatic hydrolysis of collagen proteins. Hydrolyzed collagen is widely used in cosmetics because of its biocompatibility, biodegradability and low toxicity when applied topically. It is also used as a moisturising ingredient for the stratum corneum.